WO2003064939A1 - Oil collecting method for refrigerator - Google Patents
Oil collecting method for refrigerator Download PDFInfo
- Publication number
- WO2003064939A1 WO2003064939A1 PCT/JP2003/000704 JP0300704W WO03064939A1 WO 2003064939 A1 WO2003064939 A1 WO 2003064939A1 JP 0300704 W JP0300704 W JP 0300704W WO 03064939 A1 WO03064939 A1 WO 03064939A1
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- WO
- WIPO (PCT)
- Prior art keywords
- refrigerant
- oil
- compressor
- heat source
- source unit
- Prior art date
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B31/00—Compressor arrangements
- F25B31/002—Lubrication
- F25B31/004—Lubrication oil recirculating arrangements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B13/00—Compression machines, plants or systems, with reversible cycle
Definitions
- the present invention relates to an oil recovery method for a refrigeration apparatus, and more particularly to a method for recovering oil in a pipe connecting a heat source unit and a utilization unit.
- refrigeration systems such as air conditioners equipped with a refrigerant circuit performing a vapor compression refrigeration cycle have used CFC (chlorofluorocarbon) -based refrigerants or HCFC (hydrochlorofluorocarbon) -based refrigerants.
- CFC chlorofluorocarbon
- HCFC hydrochlorofluorocarbon
- these CFC-based refrigerants and HCFC-based refrigerants had environmental problems such as destruction of the ozone layer. Therefore, it is desired to replace these existing refrigeration units with new refrigeration units that use HFC (hydrofluorocarbon) -based refrigerants or HC (hydrocarbon) -based refrigerants.
- naphthenic mineral oil or alkylbenzene oil is used as the refrigerating machine oil in a conventional refrigeration system using a CFC-based refrigerant or an HCFC-based refrigerant containing chlorine.
- This refrigerating machine oil is not compatible with HFC refrigerant containing no chlorine. If the refrigerant and the refrigerating machine oil are not compatible, the refrigerating machine oil discharged from the compressor does not return to the compressor again, and thus there is a problem that seizure occurs due to a shortage of the refrigerating machine oil.
- Refrigeration oils mainly used for HFC refrigerants or HC refrigerants that do not contain chlorine are synthetic oils such as polyol esters and polyvinyl ether.
- the refrigerating machine oil which is a synthetic oil, has a problem that, for example, if the conventional refrigerating machine oil such as mineral oil is mixed, the compatibility temperature (lower limit temperature), that is, the temperature at which the refrigerant and the refrigerating machine oil are separated increases according to the mixing ratio. Occurs. Therefore, when diverting existing pipes, it is conceivable to manually clean the pipes, but this has the problem that it takes time and effort.
- This pipe cleaning device includes a compressor, an oil separator, a four-way valve, a high / low pressure heat exchanger, a pressure reducing device, a separating device, a heat source side heat exchanger, and an accumulator. Then, the outdoor unit and the indoor unit are removed from the existing air conditioner, and only the pipe connecting the outdoor unit and the indoor unit is left.
- the pipe cleaning device is connected to one end of the pipe, and the other end of the pipe is connected by a bypass pipe to form a refrigerant circuit.
- the refrigerant circuit is filled with R 407 C of HFC-based refrigerant as a cleaning agent, and the cleaning agent is circulated to remove refrigeration oil inside the piping.
- Solution 1
- R22, R225 or R141b which is a HFCFC-based refrigerant containing chlorine, as a cleaning agent.
- R22 and R141b have a high boiling point of 32 to 56 ° C, they hardly evaporate and remain in the pipe after washing. Therefore, there is a concern that sludge or the like may be generated due to the residual cleaning agent as it is. Therefore, it is necessary to blow the inside of the pipe with nitrogen gas or the like to remove the cleaning agent. As a result, even if the above-mentioned pipe cleaning device is used, it takes a long time to recover. In addition, both cleaning agents have environmental problems.
- alkylbenzene when alkylbenzene is used, its boiling point is as high as about 300 ° C., and the same trouble as the above-mentioned HFCFC-based refrigerant is required. Furthermore, there is almost no cleaning agent having a low boiling point and no dissolution in existing refrigerating machine oil, which has no environmental problem, so that the above-described procedure must be followed.
- the present invention has been made in view of the above, and an object of the present invention is to make it possible to easily remove oil from an existing pipe without using a pipe cleaning device or the like. Disclosure of the invention
- the present invention utilizes a pump-down operation, which is a refrigerant recovery operation, to reduce the amount of oil remaining in a pipe to an allowable value or less.
- the compatibility temperature T1 at which the CFC-based refrigerant or HFCC-based refrigerant and the refrigerating machine oil dissolve is higher than the compatibility temperature T2 at which the HFC-based refrigerant or the HCC refrigerant and the refrigerating machine oil are dissolved.
- the compatible temperature T increases according to the amount of refrigeration oil in the existing refrigeration system remaining in the existing piping.
- the compatibility temperature T in the newly installed refrigeration system is lower than the compatibility temperature T1 in the existing refrigeration system (T ⁇ T1), mixing of refrigeration oil in the existing refrigeration system does not pose a problem. This is evident from the fact that compatibility temperature ⁇ 1 does not matter in existing refrigeration equipment.
- the pump-down operation provided in general refrigerant recovery equipment and refrigeration equipment is intended only for the recovery of refrigerant, and no consideration is given to the recovery of oil remaining in the piping when the pump is down.
- the triangle mark indicates the case where the preliminary operation was not performed, and the amount of oil remaining is twice the allowable value B.
- the squares in Fig. 3 indicate the case where the preliminary operation was performed, and the amount of oil remaining within the allowable value B range.
- the oil becomes mist-like, and even if there is a difference in height between the pipes, it is possible to recover the oil with a certain degree of gravity.
- the indoor heat exchanger use-side heat exchanger
- the steady oil amount in the indoor heat exchanger is the cooling cycle. It is several times as large as. As a result, the amount of oil adhering in the middle of the pipe during refrigerant recovery increases. Therefore, as shown by the circle in Fig. 3, the residual oil amount exceeds the allowable value B.
- the liquid side shutoff valve may be closed after 1-2 minutes of operation. In this case, the amount of residual oil increases rather than decreases.
- the liquid-side shut-off valve is closed before the pump-down operation, which is the refrigerant recovery operation, the amount of oil remaining within the allowable value A will be obtained.
- the liquid-side shutoff valve is closed after the pump-down operation, which is a refrigerant recovery operation, the amount of oil remaining will be several times the allowable value A.
- the existing piping can be used as it is without washing the existing piping or installing an oil recovery device.
- the first invention includes a refrigerant circuit (1A) in which a heat source unit (20) and a utilization unit (30) are connected by piping (51, 52), and performs a vapor compression refrigeration cycle. It is intended for an oil recovery method for a refrigeration system that recovers oil in the refrigerant circuit (1A) to the heat source unit (20) side. Then, in a normal cycle operation state of the refrigerant circuit (1A) in which the refrigerant condenses in the heat source unit (20), the compressor (21) of the refrigerant circuit (1A) is continuously driven, and the refrigerant circuit (1A) is driven.
- the method includes a first step of performing a circulating operation for circulating the refrigerant in the) until a predetermined time elapses.
- a recovery operation is performed in which the compressor (21) is continuously driven to recover the refrigerant in the refrigerant circuit (1A) together with oil to the heat source unit (20) side. It has a second process.
- the circulation operation and the recovery operation of the refrigerant are performed, and the oil in the pipes (51, 52) is recovered to the heat source unit (20) side.
- the second invention provides a refrigerant circuit (1A) in which a heat source unit (20) and a utilization unit (30) are connected by pipes (51, 52) to perform a vapor compression refrigeration cycle.
- the present invention is directed to an oil recovery method for a refrigeration system that recovers oil from the refrigerant circuit (1A) to the heat source unit (20). Then, in a normal cycle operation state of the refrigerant circuit (1A) in which the refrigerant condenses in the heat source unit (20), the compressor (21) of the refrigerant circuit (1A) is continuously driven, and the refrigerant circuit (1A) is driven.
- the method includes a first step of performing a circulating operation for circulating the refrigerant in the) until a predetermined time elapses.
- the circulation operation and the recovery operation of the refrigerant are performed, and in this recovery operation, the compressor (21) is temporarily stopped, and the oil in the pipes (51, 52) is discharged to the heat source unit (20) side. To be collected.
- the heat source unit (20) includes a compressor (21), a heat source side heat exchanger (23), and an expansion mechanism (24).
- the heat source unit (20) is connected to the liquid side pipe (51) via the liquid side shutoff valve (41), and is connected to the gas side pipe (52) via the gas side shutoff valve (42). It is connected to the.
- the recovery operation is started with the liquid-side stop valve (41) closed, and the gas-side stop valve (42) is closed after the completion of the recovery operation.
- the refrigerant and the oil are trapped in the heat source unit (20) by the liquid-side stop valve (41) and the gas-side stop valve (42).
- the utilization unit (30) includes a utilization-side heat exchanger (31) and a utilization-side fan (32) having a variable air volume. . Then, in the first step, the use side fan (32) is driven at a high air flow with a large air flow to perform a circulation operation.
- the utilization unit (30) includes a utilization-side heat exchanger (31) and a utilization-side fan (32) having a variable air volume. . Then, in the first step, the use side fan (32) is driven at a low air flow with a small air flow to perform a circulation operation. Therefore, in the fifth invention, since the air volume of the use side fan (32) is small, the refrigerant in the use unit (30) during the recovery operation is reduced.
- the utilization unit (30) includes a utilization-side heat exchanger (31) and a utilization-side fan (32) having a variable air volume.
- the use side fan (32) is driven at a high air flow with a large air flow in the first half of the circulation operation, and the use side fan (32) is driven at a low air flow with a small air flow in the second half of the circulation operation. Drive.
- the circulation of the refrigerant is promoted by the high air flow of the use side fan (32), and the refrigerant in the use unit (30) at the time of the recovery operation is promoted by the low air flow of the use side fan (32). Is reduced.
- the first step is such that the height difference between the pipes (51, 52) is small in accordance with the height difference between the pipes (51, 52). The shorter the cycle operation time, the shorter the time.
- the circulation operation is shortened in a horizontal pipe or the like.
- the first step is such that the length of the pipe (51, 52) is short corresponding to the length of the pipe (51, 52). The shorter the circulation operation time, the shorter the time.
- the heat source unit (20) includes a compressor (21), a heat source side heat exchanger (23), and an expansion mechanism (24). I have.
- the heat source unit (20) is provided with an oil separator (60) on the discharge side of the compressor (21) or on the downstream side of the expansion mechanism (24) in the normal cycle.
- the oil is recovered by the oil separator (60), so that the degree of freedom in controlling the recovery operation is improved.
- the oil in the pipes (51, 52) is reliably and easily recovered to the heat source unit (20) side.
- the residual amount of the refrigerating machine oil used in the existing CFC-based or HFCC-based refrigerant devices in the pipes (51, 52) can be reduced to an allowable value or less. Therefore, the pipes (51, 52) of the existing CFC-based or HCFC-based refrigerant equipment do not need to be washed with a cleaning device, etc., and the newly installed HFC-based or HC-based refrigerant equipment can be connected to the existing piping (51, 52). ) Can be installed.
- the circulation operation and the recovery operation are continuously performed while the compressor (21) is continuously driven. Oil can be collected on the heat source unit (20) side. As a result, oil recovery can be performed more reliably and promptly.
- the compressor (21) is temporarily stopped to perform the recovery operation, the refrigerant and the oil are mixed with the heat source unit (20) in a state where the refrigerant and the oil are dissolved. Can be collected on the side.
- the liquid-side stop valve (41) and the gas-side stop valve (42) are provided, the refrigerant and the oil can be reliably sealed in the heat source unit (20).
- the air volume of the use side fan (32) is set to a large high air volume, heat exchange in the use side heat exchanger (31) can be promoted to increase the refrigerant circulation.
- the refrigerant and the oil can be rapidly dissolved. As a result, the oil can be reliably recovered.
- the flow rate of the use side fan (32) is set to a small and low flow rate, so that at the end of the circulation operation, the pipes (51, 52) and the use unit are not used. (30)
- the amount of refrigerant and oil in (30) can be reduced. As a result, the oil can be reliably collected.
- the air volume of the first-side usage-side fan (32) is set to a high air volume
- the air volume of the second-half usage-side fan (32) is set to a low air volume.
- increase refrigerant circulation to promote compatibility of refrigerant and oil
- the amount of refrigerant and oil in the pipes (51, 52) and the utilization unit (30) can be reduced. As a result, the oil can be reliably collected.
- the circulation operation in the first step is performed in accordance with the height difference of the pipes (51, 52) as the height difference of the pipes (51, 52) is smaller. Since the length is shortened, the time for circulation operation can be shortened in the case of horizontal piping and the like.
- the circulation operation of the first step is performed in accordance with the length of the pipe (51, 52), and the shorter the length of the pipe (51, 52), the shorter the time of the circulation operation. Therefore, when the pipe length is short, the time of the circulation operation can be shortened.
- the oil separator (60) since the oil separator (60) is provided, it is not necessary to limit the closing time of the heat source unit (20) and the liquid side pipe (51) before the start of the recovery operation. That is, since the oil is collected by the oil separator (60), a large amount of oil does not flow out to the liquid side pipe (51) at the start of the collecting operation. As a result, the degree of freedom of the closing time is improved.
- FIG. 1 is a refrigerant circuit diagram of an air conditioner illustrating a configuration of the present invention.
- FIG. 2 is a characteristic diagram showing the residual oil amount according to the closing timing of the liquid side closing valve.
- FIG. 3 is a characteristic diagram showing the residual oil amount according to the length of the preliminary operation.
- FIG. 4 is a flowchart showing the oil recovery method according to the first embodiment of the present invention.
- FIG. 5 is a flowchart showing an oil recovery method according to Embodiment 2 of the present invention.
- FIG. 6 is a flowchart showing an oil recovery method according to Embodiment 3 of the present invention.
- FIG. 7 is a flowchart showing an oil recovery method according to Embodiment 4 of the present invention.
- the refrigeration apparatus of the present embodiment is an air conditioner (10) that switches between a cooling operation and a heating operation.
- the refrigerant circuit (1A) includes a liquid pipe (51), a gas pipe (52), and an outdoor unit (20), which is a heat source unit, and an indoor unit (30), which is a use unit. It is configured to be connected by.
- the outdoor unit (20) includes a compressor (21), a four-way switching valve (22), an outdoor heat exchanger (23) as a heat source side heat exchanger, and an electric expansion valve (24) as an expansion mechanism. ing.
- the compressor (21), the four-way switching valve (22), the outdoor heat exchanger (23), and the electric expansion valve (24) are sequentially connected by an outdoor pipe (2a) that is a refrigerant pipe.
- the outdoor heat exchanger (23) is provided with an outdoor fan (25) which is a heat source side fan.
- the indoor unit (30) includes an indoor heat exchanger (31) as a use side heat exchanger, and an indoor pipe (3a) as a refrigerant pipe is connected to the indoor heat exchanger (31). .
- the indoor heat exchanger (31) is provided with an indoor fan (32) that is a use-side fan.
- One end of the liquid pipe (51) is connected to an end of the liquid side indoor pipe (3a) in the indoor unit (30) via a connector (33) such as a flare connection.
- the other end of the gas pipe (52) is connected to the end of the indoor pipe (3a) on the gas side in the indoor unit (30) via a connector (34) such as a flare connection.
- This oil recovery method basically includes a first step of performing a preliminary operation, which is a circulation operation in which the refrigerant is circulated in the refrigerant circuit (1A) so that the refrigerant and the oil are sufficiently compatible with each other; And a second step of performing a pump-down operation, which is a recovery operation for recovering the refrigerant and the oil to the outdoor unit (20) in a state where they are sufficiently compatible.
- step ST1 the refrigerant circuit (1A) is set to the cooling operation mode. That is, the four-way switching valve (22) is switched to the solid line side in FIG. 1, and the refrigerant circuit (1A) is set to the state of the cooling cycle, which is the normal cycle. Further, the temperature set value in the room is set to the lowest value so that the compressor (21) is driven continuously.
- step ST2 start the first process, and operate the cooling cycle.
- Start cooling operation (circulation operation).
- step ST3 start counting the operation time of the cooling operation, and proceeds to step ST4 to determine whether or not the compressor (21) has stopped. If the compressor (21) is continuously driven, the process proceeds from step ST4 to step ST5, where it is determined whether or not the cooling operation has been performed for a predetermined time. Returning to ST4, the above operation is repeated, and the compressor (21) performs a preliminary operation in which the compressor (21) is continuously driven.
- the predetermined time of step ST5 is set to, for example, 30 minutes. That is, when the cooling operation is started, the refrigerant circulates in the refrigerant circuit (1A). However, in order for the refrigerant and the refrigerating machine oil to be compatible, the refrigerant circulates in the refrigerant circuit (1A) for a predetermined time. There is a need. Thus, for example, a cooling operation for 30 minutes is performed so that the refrigerant and the refrigerating machine oil are compatible.
- step ST5 determines whether the cooling operation is temporarily stopped. That is, the continuous driving of the compressor (21) is temporarily stopped.
- step ST7 where the liquid-side shutoff valve (41) is fully closed.
- the liquid-side shutoff valve (41) is manually closed, and the outdoor piping (2a) of the outdoor unit (20) and the liquid piping are connected. (51) is closed.
- step ST8 it is determined whether or not the stop time of the compressor (21) is longer than a predetermined time. That is, if the stop time of the compressor (21) is long, the refrigerating machine oil becomes droplets.
- step ST8 YES
- step ST8 determines whether the stop time of the compressor (21) is within the predetermined time. If the stop time of the compressor (21) is within the predetermined time, the determination in step ST8 is NO and the process proceeds to step ST9, where the refrigerant circuit (1A) remains in the normal cycle. Starts the cooling operation which is the recovery operation. That is, although the air-conditioning apparatus (10) of the present embodiment does not have a pump-down function, since the liquid-side stop valve (41) is closed, the pump-down operation is started by the start of the cooling operation. Become. Subsequently, the process proceeds to step ST10, where it is determined whether or not the pump-down operation has been performed for a predetermined time, and the pump-down operation is performed until the predetermined time has elapsed.
- step ST11 the gas side shut-off valve (42) is fully closed, and the process proceeds to step ST12 to stop the cooling operation. That is, the cooling operation, which is the pump-down operation, is stopped, and the second process ends. By this cooling operation, the refrigerating machine oil is confined in the outdoor unit (20).
- step ST4 if the compressor (21) stops during the cooling operation which is the circulation operation, the compatibility of the refrigerant and the oil is not promoted. Therefore, the process proceeds to step ST13 to reset the time count of the cooling operation. And return to step ST3 to continue the cooling operation.
- the indoor fan (32) operates at a high air flow.
- the air volume of the indoor fan (32) can be set to four levels: strong, medium, low, and light, set the maximum air volume to “strong” or a large air volume to “medium”.
- heat exchange in the indoor heat exchanger (31) can be promoted to increase the refrigerant circulation.
- the air volume of the room / fan (32) may be set to “minimum air volume” of the minimum air volume or “weak” of the small air volume.
- the refrigerant circulation amount is small, the refrigerant amount and the oil amount in the liquid pipe (51), the gas pipe (52), and the indoor unit (30) can be reduced at the end of the circulation operation.
- the air volume of the indoor fan (32) is set to “strong” of the maximum air volume or “medium” of the large air volume, and in the second half, the air volume of the indoor fan (32) is minimized.
- the air volume may be set to “light wind” or a small air volume “weak”.
- the refrigerant circulation is increased to promote the compatibility between the refrigerant and the oil, while in the second half, the liquid pipe (51) and the gas pipe (52) are connected to the indoor unit. (30)
- the amount of refrigerant and the amount of oil in (30) can be reduced. Effect of Embodiment 1
- the oil in the liquid pipe (51) and the gas pipe (52) is reliably supplied to the outdoor unit (20) side. And it can be easily collected.
- the residual amount of the refrigerating machine oil used in the existing CFC-based refrigerant or HFCC-based refrigerant in the liquid pipe (51) and the gas pipe (52) can be reduced to an allowable value or less. Therefore, the liquid pipe (51) and gas pipe (52) of the existing CFC-based or HCFC-based refrigerant system need not be cleaned with a cleaning device or the like. It can be connected to the liquid pipe (51) and the gas pipe (52).
- the heat exchange in the indoor heat exchanger (31) can be promoted to increase the circulation of the refrigerant, and the compatibility of the refrigerant and the oil can be rapidly increased. Can be done. As a result, the oil can be reliably recovered.
- the air volume of the indoor fan (32) is set to a small low air volume, so that the amount of refrigerant circulated is small, so that at the end of circulation operation, the liquid pipe (51) and gas pipe (52) and the indoor unit (30) , The amount of refrigerant and the amount of oil can be reduced. As a result, the oil can be reliably recovered.
- an air conditioner (10) having a pump-down function is provided instead of the air conditioner (10) having no pump-down function in the first embodiment. This is the case.
- the oil recovery method of the air conditioner (10) is the same as that of the first embodiment except that step ST9 in FIG. 4 in the first embodiment replaces step ST29 in FIG.
- Step ST 21 the four-way switching valve (22) is switched to the solid line side in Fig. 1, the refrigerant circuit (1A) is set in the cooling cycle state, which is the normal cycle, and the indoor temperature set value is set to the lowest value.
- the cooling operation which is the operation of the cooling cycle
- the operation time of this cooling operation is counted
- the compressor (21) is driven continuously. If so, the above operation is repeated until a predetermined time elapses, and the refrigerant is circulated (step ST22 to step ST25).
- step ST26 the continuous driving of the compressor (21) is temporarily stopped to stop the cooling operation, and the first step is performed.
- the second process starts (step ST26).
- the liquid-side stop valve (41) is fully closed, and it is determined whether or not the stop time of the compressor (21) is longer than a predetermined time. After 30 minutes, the cooling operation, which is the circulation operation, is restarted (step ST27 and step ST28).
- step ST29 the refrigerant recovery operation switch, which is the pump down operation switch, is turned ON.
- the system waits for the refrigerant recovery operation, which is the pump-down operation, to be performed for a predetermined time.
- the gas-side shut-off valve (42) is fully closed, the refrigerant recovery operation is stopped, and the second process is performed. (Step ST30 to Step ST32). This By the refrigerant recovery operation, the refrigerating machine oil is confined in the outdoor unit (20).
- step ST24 the compressor is operated during the cooling operation, which is a circulation operation.
- step ST33 When (21) stops, the process moves to step ST33, resets the time count of the cooling operation, returns to step ST23, and continues the cooling operation.
- Other configurations, operations, and effects are the same as those of the first embodiment.
- the above pump down function is generally a function of automatically performing a pump down operation.
- This automatic pump-down operation simulates a manual pump-down operation.
- the electric expansion valve (24) is fully closed as an alternative to fully closing the liquid-side stop valve (41). There are cases.
- the liquid side closing valve (41) is fully closed in step ST27.
- the timing of fully closing the liquid side closing valve (41) may be the end point of the pump down. . Therefore, in step ST27, the liquid-side stop valve (41) is fully closed.
- the circulation operation is performed while the compressor (21) is continuously driven.
- the recovery operation is performed continuously.
- the oil recovery method in this air conditioner (10) is different from the first embodiment in that steps ST6, ST8, and ST9 in FIG. Other than the above is the same as the first embodiment.
- Step ST41 the four-way switching valve (22) is switched to the solid line side in Fig. 1, the refrigerant circuit (1A) is set in the cooling cycle state, which is the normal cycle, and the indoor temperature set value is set to the lowest value.
- the cooling operation which is the operation of the cooling cycle
- the operation time of this cooling operation is counted
- the compressor (21) is driven continuously. If so, the above operation is repeated until a predetermined time elapses, and the refrigerant is circulated (step ST42 to step ST45).
- the first step is completed while the compressor (21) is continuously driven, and the liquid side is closed simultaneously.
- the second step is started by fully closing the valve (41) (step ST46).
- the liquid-side shut-off valve (41) is closed to start the pumping-down recovery operation. That is, although the air-conditioning apparatus (10) of the present embodiment does not have a pump-down function, the liquid-side closing valve (41) is closed, so that the pump-down operation is started. Wait for the pump-down operation to be performed for a predetermined time, and after the predetermined time has elapsed, close the gas side shut-off valve (42) completely, stop the cooling operation that is the pump-down operation, and execute the second step. The process ends (step ST47 to step ST49). By this cooling operation, the refrigerating machine oil is confined in the outdoor unit (20).
- step ST44 the compressor is operated during the cooling operation, which is the circulation operation.
- step ST50 When (21) stops, the process moves to step ST50, resets the cooling operation time count, returns to step ST43, and continues the cooling operation.
- the circulation operation and the recovery operation are continuously performed while the compressor (21) is continuously driven, so that the refrigerant and the oil are mixed with each other. Refrigerant and oil can be recovered to the outdoor unit (20). As a result, oil recovery can be performed more reliably and promptly.
- Other configurations, operations, and effects are the same as those of the first embodiment.
- an air conditioner (10) having a pump-down function is provided instead of the air conditioner (10) having no pump-down function in the third embodiment. This is the case.
- the oil recovery method of this air conditioner (10) is the same as that of the third embodiment except that step ST67 of FIG. 7 is added after step ST46 of FIG. 6 in the third embodiment. is there.
- Step ST61 the four-way switching valve (22) is switched to the solid line side in Fig. 1, the refrigerant circuit (1A) is set in the cooling cycle state, which is the normal cycle, and the indoor temperature set value is set to the lowest value.
- the cooling operation which is the operation of the cooling cycle
- the operation time of this cooling operation is counted
- the compressor (21) is driven continuously. If so, the above operation is repeated until a predetermined time has elapsed, and the refrigerant is circulated (step ST62 to step ST65).
- the first step is completed while the compressor (21) is continuously driven, and the liquid side is closed simultaneously.
- the second step is started by fully closing the valve (41) (step ST46).
- Step ST67 to Step ST70 the refrigerant recovery operation switch which is the pump down operation switch is turned on, and the recovery operation which is the pump down operation is started.
- Step ST67 to Step ST70 the refrigerant recovery operation that is the pump-down operation, and end the second process.
- step ST64 the compressor is operated during the cooling operation, which is the circulation operation.
- step ST71 When (21) stops, the process moves to step ST71, resets the cooling operation time count, returns to step ST63, and continues the cooling operation.
- the cooling operation is performed as the circulating operation.
- the normal cycle operation cooling cycle operation
- the reheat dehumidification operation the inverter rated cooling operation for performing the inverter control
- the emergency operation the forced operation
- Any of the cooling operation may be used.
- the above emergency operation is temporarily stopped when a protection circuit such as protection of high pressure is operating.
- the operation will be restarted after the elapse of the specified time. Therefore, it is rare that the compressor (21) stops during the emergency operation which is the circulation operation.
- the time when the compressor (21) is restarted is set as a starting point. Start the time measurement again (for example, see step ST4 and step ST13 in Fig. 4).
- the forcible operation is an operation for the purpose of a pump-down operation or a forcible defrosting operation, in which the refrigerant circuit (1A) is fixed, and the actuator also basically has a fixed value.
- this forced operation frequent start / stop due to low load is eliminated, and continuous operation can be reliably performed.
- the cooling operation which is the recovery operation
- the cooling operation is manually stopped, but may be automatically stopped. That is, as shown by the dashed line in FIG. 1, when the compressor (21) has a low-pressure switch (61) on the suction side, when the low-pressure refrigerant pressure falls below the lower limit, the low-pressure switch (61) May be operated to forcibly stop the compressor (21) and stop the recovery operation.
- the driving time may be shortened.
- the time for the pre-operation which is the circulating operation, can be shortened.
- the circulating operation in the first step is such that the shorter the length of the liquid pipe (51) and the gas pipe (52) is, the shorter the length of the liquid pipe (51) and the gas pipe (52) is. May be shortened. As a result, when the pipe length is short, the time for the preliminary operation, which is the circulation operation, can be shortened.
- the outdoor unit (20) has an oil separator (60) on the discharge side of the compressor (21) or on the downstream side of the electric expansion valve (24) in the cooling cycle, as shown by the dashed line in FIG. May be provided.
- this oil separator (60) When this oil separator (60) is installed, the closing time of the liquid side shut-off valve (41) is limited to before the start of the pump-down operation, which is the recovery operation. No need. That is, since the oil is collected by the oil separator (60), a large amount of oil does not flow out to the liquid pipe (51) at the start of the pump-down operation. As a result, the degree of freedom of the closing timing of the liquid side closing valve (41) is improved.
- one indoor unit (30) is provided, but the present invention may include a plurality of indoor units (30).
- the liquid side closing valve (41) is provided as the liquid side closing mechanism.
- the electric expansion valve (24) can be controlled to be fully closed, the liquid side closing mechanism is electrically expanded. It may be constituted by the valve (24) and the liquid-side shut-off valve (41) may be omitted.
- the present invention is not limited to the air conditioner (10), and it is needless to say that the present invention can be applied to various refrigeration devices. Industrial applicability
- the oil recovery method for a refrigerating apparatus is useful for recovering oil from a pipe connecting a heat source unit and a utilization unit, and particularly, an HFC-based refrigerant or an HC-based refrigerant. Suitable for oil recovery when upgrading to a new refrigeration unit using
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Abstract
An oil collecting method for collecting oil in a refrigerating circuit (1A) to an outdoor unit (20) in a refrigerator having the outdoor unit (20) and an indoor unit (30) connected to each other through pipes (51, 52) and the refrigerating circuit (1A) for performing a vapor compression refrigerating cycle, comprising a first step for continuously driving a compressor (21) in the refrigerating circuit (1A) in the operating state of normal cycle of the refrigerating circuit (1A) where refrigerant is condensed in the outdoor unit (20) to perform a circulating operation to circulate the refrigerant in the refrigerant circuit (1A) until a specified time is elapsed and a second step for closing a liquid side stop valve (41) and continuously driving the compressor (21) to perform a collecting operation to collect the refrigerant in the refrigerant circuit (1A) together with oil to the outdoor unit (20).
Description
明 細 書 冷凍装置の油回収方法 技術分野 Description Oil recovery method for refrigeration equipment Technical field
本発明は、 冷凍装置の油回収方法に関し、 特に、 熱源ユニットと利用ュニッ トとを接続する配管の油を回収する方法に係るものである。 背景技術 The present invention relates to an oil recovery method for a refrigeration apparatus, and more particularly to a method for recovering oil in a pipe connecting a heat source unit and a utilization unit. Background art
従来より、 蒸気圧縮式冷凍サイクルを行う冷媒回路を備えた空気調和装置等 の冷凍装置には、 C F C (クロ口フルォロカーボン) 系冷媒又は HC F C (ハイ ドロクロ口フルォロカーボン) 系冷媒が用いられていたが、 この CF C系冷媒及 び HC FC系冷媒は、 オゾン層の破壊等の環境上の問題があった。 そこで、 これ ら既設の冷凍装置から、 HF C (ハイ ドロフルォロカーボン) 系冷媒又は HC (ハ ィ ドロカーボン) 系冷媒を使用した新たな冷凍装置に更新することが望まれてい る。 Conventionally, refrigeration systems such as air conditioners equipped with a refrigerant circuit performing a vapor compression refrigeration cycle have used CFC (chlorofluorocarbon) -based refrigerants or HCFC (hydrochlorofluorocarbon) -based refrigerants. However, these CFC-based refrigerants and HCFC-based refrigerants had environmental problems such as destruction of the ozone layer. Therefore, it is desired to replace these existing refrigeration units with new refrigeration units that use HFC (hydrofluorocarbon) -based refrigerants or HC (hydrocarbon) -based refrigerants.
この冷凍装置の更新時において、 配管が建物内部に埋め込まれていることが 多いので、 配管の入れ替えが難しい。 そこで、 既設の配管をそのまま流用して新 たな冷凍装置を導入することが行われている。 When renewing this refrigeration system, it is difficult to replace the pipes because the pipes are often embedded inside the building. Therefore, a new refrigeration system is being introduced by diverting the existing piping as it is.
一方、 塩素分を含む C F C系冷媒又は H C FC系冷媒を用いた従来の冷凍装 置における冷凍機油は、 ナフテン系の鉱油やアルキルベンゼン油系が使われてい る。 この冷凍機油は、 塩素分を含まない HF C系冷媒と相溶しない。 冷媒と冷凍 機油が相溶しない場合、 圧縮機から吐き出された冷凍機油が再び圧縮機に戻らな いので、 冷凍機油の不足による焼き付きが生じるという問題がある。 On the other hand, naphthenic mineral oil or alkylbenzene oil is used as the refrigerating machine oil in a conventional refrigeration system using a CFC-based refrigerant or an HCFC-based refrigerant containing chlorine. This refrigerating machine oil is not compatible with HFC refrigerant containing no chlorine. If the refrigerant and the refrigerating machine oil are not compatible, the refrigerating machine oil discharged from the compressor does not return to the compressor again, and thus there is a problem that seizure occurs due to a shortage of the refrigerating machine oil.
塩素分を含まない HF C系冷媒又は HC系冷媒に主に使われている冷凍機油 は、 ポリオールエステルやポリビニールエーテルなどの合成油である。 この合成 油である冷凍機油は、 従来の鉱油等の冷凍機油が混入すると、 混入割合に応じて 相溶温度 (下限温度)、 つまり、 冷媒と冷凍機油とが分離する温度が上昇するな どの問題が生ずる。
したがって、 既設の配管を流用する場合、 人手によって配管を洗浄すること が考えられるが、 これでは手間がかかるという問題がある。 Refrigeration oils mainly used for HFC refrigerants or HC refrigerants that do not contain chlorine are synthetic oils such as polyol esters and polyvinyl ether. The refrigerating machine oil, which is a synthetic oil, has a problem that, for example, if the conventional refrigerating machine oil such as mineral oil is mixed, the compatibility temperature (lower limit temperature), that is, the temperature at which the refrigerant and the refrigerating machine oil are separated increases according to the mixing ratio. Occurs. Therefore, when diverting existing pipes, it is conceivable to manually clean the pipes, but this has the problem that it takes time and effort.
そこで、 特開 2 0 0 1— 1 4 1 3 4 0号公報に開示されているように、 配管 を洗浄する配管洗浄装置が提案されている。 この配管洗浄装置は、 圧縮機と油分 離器と四方弁と高低圧熱交換器と減圧装置と分離装置と熱源側熱交換器とアキュ ムレータとを備えている。 そして、 既設の空気調和装置から室外ユニッ トと室内 ュニッ トとを取り外し、 該室外ュニッ トと室内ュニットとを接続する配管のみを 残す。 この配管の一端に上記配管洗浄装置を接続する一方、 上記配管の他端をバ ィパス管によって接続して冷媒回路を構成する。 Therefore, a pipe cleaning device for cleaning pipes has been proposed as disclosed in Japanese Patent Application Laid-Open No. 2001-141340. This pipe cleaning device includes a compressor, an oil separator, a four-way valve, a high / low pressure heat exchanger, a pressure reducing device, a separating device, a heat source side heat exchanger, and an accumulator. Then, the outdoor unit and the indoor unit are removed from the existing air conditioner, and only the pipe connecting the outdoor unit and the indoor unit is left. The pipe cleaning device is connected to one end of the pipe, and the other end of the pipe is connected by a bypass pipe to form a refrigerant circuit.
上記冷媒回路に H F C系冷媒の R 4 0 7 Cを洗浄剤として充填し、 この洗浄 剤を循環させて配管の内部の冷凍機油を除去するようにしている。 一解決課題一 The refrigerant circuit is filled with R 407 C of HFC-based refrigerant as a cleaning agent, and the cleaning agent is circulated to remove refrigeration oil inside the piping. Solution 1
上述したように、 従来の配管洗浄装置を用いると、 極めて高価になるという 問題があった。 As described above, there has been a problem that the use of a conventional pipe cleaning device is extremely expensive.
また一方、 洗浄剤として塩素分を含む H C F C系冷媒である R 2 2、 R 2 2 5又は R 1 4 1 b等を用いることも考えられている。 しかしながら、 この R 2 2 5及び R 1 4 1 bは、 沸点が 3 2〜 5 6 °Cと高いため、 蒸発し難く、 洗浄後も配 管に残留したままとなる。 したがって、 そのままでは残留した洗浄剤によるスラ ッジ等の発生が懸念されるので、 窒素ガス等で配管内をブローして洗浄剤を除去 する必要がある。 この結果、上記配管洗浄装置を使用しても回収に時間がかかる。 加えて、 いずれの洗浄剤も環境上の問題がある。 On the other hand, it has been considered to use R22, R225 or R141b, which is a HFCFC-based refrigerant containing chlorine, as a cleaning agent. However, since R22 and R141b have a high boiling point of 32 to 56 ° C, they hardly evaporate and remain in the pipe after washing. Therefore, there is a concern that sludge or the like may be generated due to the residual cleaning agent as it is. Therefore, it is necessary to blow the inside of the pipe with nitrogen gas or the like to remove the cleaning agent. As a result, even if the above-mentioned pipe cleaning device is used, it takes a long time to recover. In addition, both cleaning agents have environmental problems.
また、アルキルベンゼンを使用した場合も、その沸点が 3 0 0 °C前後と高く、 上述の H C F C系冷媒と同様の手間がかかる。 更に、 環境上の問題がなく沸点が 低い洗浄剤で既存の冷凍機油に溶解しゃすいものはほとんど存在しないため、 上 述した手順を踏まざるを得ないという問題があった。 Also, when alkylbenzene is used, its boiling point is as high as about 300 ° C., and the same trouble as the above-mentioned HFCFC-based refrigerant is required. Furthermore, there is almost no cleaning agent having a low boiling point and no dissolution in existing refrigerating machine oil, which has no environmental problem, so that the above-described procedure must be followed.
本発明は、 斯かる点に鑑みて成されたもので、 配管洗浄装置等を用いること なく、 既設の配管の油を容易に除去し得るようにすることを目的とするものであ る。
発明の開示 The present invention has been made in view of the above, and an object of the present invention is to make it possible to easily remove oil from an existing pipe without using a pipe cleaning device or the like. Disclosure of the invention
—発明の概要一 —Summary of the Invention I
本発明は、 冷媒の回収運転であるポンプダウン運転を利用して配管における 油の残留量を許容値以下になるようにしたものである。 The present invention utilizes a pump-down operation, which is a refrigerant recovery operation, to reduce the amount of oil remaining in a pipe to an allowable value or less.
つまり、 本願発明者らは、 配管の油の除去に関して永年研究した結果、 下記 の事項を見出したものである。 In other words, the inventors of the present application have found the following matters as a result of long-term research on the removal of oil from piping.
C F C系冷媒又は H C F C系冷媒と冷凍機油とが溶解する相溶温度 T 1は、 H F C系冷媒又は H C系冷媒と冷凍機油とが溶解する相溶温度 T 2より高い。 新 設の冷凍装置においては、 既設の配管に残留した既存の冷凍装置の冷凍機油の混 入量に応じて相溶温度 Tが上昇する。 しかし、 この新設の冷凍装置における相溶 温度 Tが既存の冷凍装置における相溶温度 T 1より低ければ (T < T 1 )、 既存 の冷凍装置の冷凍機油の混入は問題とならない。 この点、 既存の冷凍装置におい て、 相溶温度 Τ 1が問題とならないことから明らかである。 The compatibility temperature T1 at which the CFC-based refrigerant or HFCC-based refrigerant and the refrigerating machine oil dissolve is higher than the compatibility temperature T2 at which the HFC-based refrigerant or the HCC refrigerant and the refrigerating machine oil are dissolved. In the new refrigeration system, the compatible temperature T increases according to the amount of refrigeration oil in the existing refrigeration system remaining in the existing piping. However, if the compatibility temperature T in the newly installed refrigeration system is lower than the compatibility temperature T1 in the existing refrigeration system (T <T1), mixing of refrigeration oil in the existing refrigeration system does not pose a problem. This is evident from the fact that compatibility temperature Τ1 does not matter in existing refrigeration equipment.
この結果、 既設の配管において、 既存の冷凍装置における冷凍機油の残留量 に許容値があることになる。 As a result, in the existing piping, there is an allowable value for the residual amount of refrigerating machine oil in the existing refrigerating equipment.
一方、 一般の冷媒回収装置や冷凍装置に備わっているポンプダウン運転は、 冷媒の回収のみを目的としているため、 ポンプダウン時に配管内に残留する油の 回収については全く考慮されていない。 On the other hand, the pump-down operation provided in general refrigerant recovery equipment and refrigeration equipment is intended only for the recovery of refrigerant, and no consideration is given to the recovery of oil remaining in the piping when the pump is down.
しかしながら、 本願発明者らは、 鋭意研究の結果、 既存の冷凍装置のポンプ ダウン運転を利用して冷媒のみならず既設の配管の冷凍機油の残留量を許容範囲 に回収し得る事項を見出したもので、 この事項は次の通りである。 However, as a result of earnest research, the inventors of the present application have found that it is possible to collect not only the refrigerant but also the remaining amount of the refrigerating machine oil in the existing piping to an allowable range using the pump-down operation of the existing refrigerating device. Then, this matter is as follows.
( 1 ) 回収運転であるポンプダウン運転時に油も回収するには、 ポンプダウン運 転前に循環運転である事前運転が必要である。 (1) In order to collect oil during the pump-down operation, which is a recovery operation, a preliminary operation, which is a circulation operation, is required before the pump-down operation.
つまり、 冷媒と冷凍機油の相溶性を高めるために冷媒が冷媒回路を循環する 事前運転が必要である。 この事前運転を行わない場合、 ポンプダウン運転前にお いて、 油が大きな油滴となって利用ュニッ トである室内機に寝込んだ状態となつ ている。 特に、 熱源ユニッ トである室外機を屋上に設置し、 室外機と室内機との 高低差が大きいような設置環境では、 ポンプダウン運転時に室内機に滞留してい
る冷媒と油とを重力に逆らって室外機に回収しなければならない。 油が冷媒から 分離して油滴となっていると、 油が重力に負けて室外機まで回収されず、 配管の 途中に付着したままとなるからである。 そこで、 冷媒と冷凍機油とを充分に相溶 させる事前運転を行うこととした。 In other words, it is necessary to perform a preliminary operation in which the refrigerant circulates through the refrigerant circuit in order to increase the compatibility between the refrigerant and the refrigerating machine oil. If this preliminary operation is not performed, before the pump-down operation, the oil will fall into large oil droplets and be laid down in the indoor unit, which is the utilization unit. In particular, in an installation environment where the outdoor unit, which is a heat source unit, is installed on the rooftop and the height difference between the outdoor unit and the indoor unit is large, the outdoor unit stays in the indoor unit during the pump-down operation. Refrigerant and oil must be recovered by the outdoor unit against gravity. If the oil separates from the refrigerant to form oil droplets, the oil will lose its gravity and will not be collected in the outdoor unit, but will remain attached to the piping. Therefore, we decided to perform preliminary operation to make the refrigerant and the refrigerating machine oil sufficiently compatible.
この点、 図 3に示すように、 三角印は事前運転を行わなかった場合であり、 許容値 Bの 2倍の油の残留量となる。 これに対し、 図 3の四角印は事前運転を行 つた場合であり、 許容値 Bの範囲内の油の残留量となる。 In this regard, as shown in Fig. 3, the triangle mark indicates the case where the preliminary operation was not performed, and the amount of oil remaining is twice the allowable value B. On the other hand, the squares in Fig. 3 indicate the case where the preliminary operation was performed, and the amount of oil remaining within the allowable value B range.
( 2 ) 事前運転 (循環運転) は、 正サイクルである冷房サイクルによる連続運転 でなければならない。 (2) Preliminary operation (circulation operation) must be continuous operation with the cooling cycle, which is the normal cycle.
つまり、 事前運転を行うので、 油がミス ト状となり、 配管に高低差があって も重力にある程度勝って回収することが可能である。 これに対し、 逆サイクルで ある暖房サイクルの運転の場合、 室内熱交換器 (利用側熱交換器) が凝縮器とな るため、 室内熱交換器内の定常的な油量が冷房サイクルの場合に比較して数倍と なる。 この結果、 冷媒回収時に配管の途中における油の付着量が増大する。 この ため、 図 3丸印に示すように、 残油量が許容値 Bを超える。 In other words, since the pre-operation is performed, the oil becomes mist-like, and even if there is a difference in height between the pipes, it is possible to recover the oil with a certain degree of gravity. On the other hand, in the case of the heating cycle operation, which is the reverse cycle, the indoor heat exchanger (use-side heat exchanger) becomes a condenser, and the steady oil amount in the indoor heat exchanger is the cooling cycle. It is several times as large as. As a result, the amount of oil adhering in the middle of the pipe during refrigerant recovery increases. Therefore, as shown by the circle in Fig. 3, the residual oil amount exceeds the allowable value B.
尚、 強制的に連続運転を行う冷房サイクルの強制運転ではなく通常の冷房運 転の場合、 室内及び室外の環境によっては負荷が不足し、 運転及び停止を繰り返 す場合がある。 この場合、 冷媒の循環が悪くなると共に、 再起動時の油の流出量 も多くなるため、 室内熱交換器の油の貯留量が増大する。 つまり、 回収運転時に おける配管に付着する油量が増える。 したがって、 通常の冷房運転で事前運転を 行う場合は、 圧縮機が所定時間連続して稼動することが必要である。 In addition, in the case of normal cooling operation, not forced operation of the cooling cycle in which forced continuous operation is performed, the load may be insufficient depending on the indoor and outdoor environment, and the operation and stop may be repeated. In this case, the circulation of the refrigerant is deteriorated, and the amount of oil flowing out at the time of restart is increased, so that the amount of oil stored in the indoor heat exchanger is increased. In other words, the amount of oil adhering to the piping during the recovery operation increases. Therefore, when pre-operation is performed in normal cooling operation, it is necessary for the compressor to operate continuously for a predetermined time.
( 3 ) 事前運転の終了からポンプダウン運転の開始までの間は運転を停止させず に行う。 または、 運転を停止しなければならない場合は、 原則的に事前運転の終 了後に液側閉鎖弁を閉めてからポンプダウン運転を開始しなければならない。 (3) From the end of the pre-operation to the start of the pump-down operation, perform the operation without stopping. Or, when the operation must be stopped, the pump must be closed after closing the liquid side shut-off valve after the end of the preliminary operation.
つまり、運転開始時には、圧縮機等に溜まりこんだ油が一気に流れ出すため、 ポンプダウン運転の開始後に液側閉鎖弁を閉めると、 配管及び室内熱交換器内に 多大な油が付着して回収が困難となる。 一般のポンプダウン運転には、 1〜2分 運転した後、 液側閉鎖弁を閉める場合がある。 この場合、 油の残留量が減るどこ ろか増大する。
この点、 図 2に示すように、 冷媒の回収運転であるポンプダウン運転前に液 側閉鎖弁を閉めると、 許容値 Aの範囲内の油の残留量となる。 これに対し、 冷媒 の回収運転であるポンプダウン運転後に液側閉鎖弁を閉めると、 許容値 Aの数倍 の油の残留量となる。 In other words, at the start of operation, the oil that has accumulated in the compressor etc. flows out at once, so if the liquid side stop valve is closed after the start of the pump-down operation, a large amount of oil will adhere to the pipes and the indoor heat exchanger and will be recovered. It will be difficult. In general pump-down operation, the liquid side shutoff valve may be closed after 1-2 minutes of operation. In this case, the amount of residual oil increases rather than decreases. At this point, as shown in Fig. 2, if the liquid-side shut-off valve is closed before the pump-down operation, which is the refrigerant recovery operation, the amount of oil remaining within the allowable value A will be obtained. On the other hand, if the liquid-side shutoff valve is closed after the pump-down operation, which is a refrigerant recovery operation, the amount of oil remaining will be several times the allowable value A.
( 4 ) 事前運転の終了後、 運転を一 B停止してからポンプダウン運転を行う場合 は、 事前運転の終了からポンプダウン運転の開始までの時間を極力短くすること が必要である。 (4) When the pump-down operation is performed after stopping the operation by one B after the end of the preliminary operation, it is necessary to minimize the time from the end of the preliminary operation to the start of the pump-down operation.
つまり、 運転を停止している間に急速に冷媒が冷え込み油の粘度が増すと共 に、 油滴となってしまうため、 ポンプダウン運転を開始するまでの停止時間には 制限がある。 特に暖房期には顕著である。 所定時間以上の運転停止が継続した場 合は、 再び事前運転を行うことが必要である。 In other words, while the operation is stopped, the refrigerant rapidly cools down and the viscosity of the oil increases, resulting in oil droplets. Therefore, there is a limit to the stop time before starting the pump-down operation. This is particularly noticeable during the heating period. If the operation has been stopped for more than the specified time, it is necessary to perform the preliminary operation again.
上記 ( 1 ) 〜 (4 ) の事項を遵守することにより、 既設の配管の洗浄や油回 収器等を設置することなく、 既設の配管をそのまま利用することができる。 一解決手段一 By observing the above items (1) to (4), the existing piping can be used as it is without washing the existing piping or installing an oil recovery device. One solution one
具体的に、 第 1の発明は、 熱源ユニッ ト (20) と利用ユニッ ト (30) とが 配管 (51, 52) によって接続され、蒸気圧縮式冷凍サイクルを行う冷媒回路 (1A) を備え、 該冷媒回路 (1A) の油を熱源ユニッ ト (20) 側に回収する冷凍装置の 油回収方法を対象と している。 そして、 上記熱源ユニッ ト (20) で冷媒が凝縮 する冷媒回路 (1A) の正サイクルの運転状態において、 上記冷媒回路 (1A) の 圧縮機 (21 ) を連続して駆動させ、 冷媒回路 (1A) 内で冷媒を循環させる循環 運転を所定時間が経過するまで行う第 1の工程を備えている。 加えて、 上記第 1 の工程に続き、 上記圧縮機 (21 ) を継続して駆動して上記冷媒回路 (1A) の冷 媒を油と共に熱源ユニッ ト (20) 側に回収する回収運転を行う第 2の工程を備 えている。 Specifically, the first invention includes a refrigerant circuit (1A) in which a heat source unit (20) and a utilization unit (30) are connected by piping (51, 52), and performs a vapor compression refrigeration cycle. It is intended for an oil recovery method for a refrigeration system that recovers oil in the refrigerant circuit (1A) to the heat source unit (20) side. Then, in a normal cycle operation state of the refrigerant circuit (1A) in which the refrigerant condenses in the heat source unit (20), the compressor (21) of the refrigerant circuit (1A) is continuously driven, and the refrigerant circuit (1A) is driven. The method includes a first step of performing a circulating operation for circulating the refrigerant in the) until a predetermined time elapses. In addition, following the first step, a recovery operation is performed in which the compressor (21) is continuously driven to recover the refrigerant in the refrigerant circuit (1A) together with oil to the heat source unit (20) side. It has a second process.
したがって、第 1の発明では、冷媒の循環運転と回収運転とを行い、配管(51, 52) の油を熱源ユニッ ト (20) 側に回収する。 Therefore, in the first invention, the circulation operation and the recovery operation of the refrigerant are performed, and the oil in the pipes (51, 52) is recovered to the heat source unit (20) side.
また、 第 2の発明は、 熱源ユニッ ト (20) と利用ユニッ ト (30) とが配管 (51, 52) によって接続され、 蒸気圧縮式冷凍サイクルを行う冷媒回路 (1A)
を備え、 該冷媒回路 (1A) の油を熱源ユニッ ト (20) 側に回収する冷凍装置の 油回収方法を対象としている。 そして、 上記熱源ユニッ ト (20) で冷媒が凝縮 する冷媒回路 (1A) の正サイクルの運転状態において、 上記冷媒回路 (1A) の 圧縮機 (21 ) を連続して駆動させ、 冷媒回路 (1A) 内で冷媒を循環させる循環 運転を所定時間が経過するまで行う第 1の工程を備えている。 加えて、 上記第 1 の工程が終了すると、 上記圧縮機 (21 ) を一旦停止した後、 該圧縮機 (21 ) を 駆動して上記冷媒回路 (1A) の冷媒を油と共に熱源ユニッ ト (20) 側に回収す る回収運転を行う第 2の工程とを備えている。 The second invention provides a refrigerant circuit (1A) in which a heat source unit (20) and a utilization unit (30) are connected by pipes (51, 52) to perform a vapor compression refrigeration cycle. The present invention is directed to an oil recovery method for a refrigeration system that recovers oil from the refrigerant circuit (1A) to the heat source unit (20). Then, in a normal cycle operation state of the refrigerant circuit (1A) in which the refrigerant condenses in the heat source unit (20), the compressor (21) of the refrigerant circuit (1A) is continuously driven, and the refrigerant circuit (1A) is driven. The method includes a first step of performing a circulating operation for circulating the refrigerant in the) until a predetermined time elapses. In addition, when the first step is completed, the compressor (21) is temporarily stopped, and then the compressor (21) is driven to drive the refrigerant of the refrigerant circuit (1A) together with oil to the heat source unit (20). ) Side, and a second step of performing a recovery operation for recovery.
したがって、 第 2の発明では、 冷媒の循環運転と回収運転とを行い、 この回 収運転で圧縮機 (21 ) を一旦停止して配管 (51, 52) の油を熱源ユニッ ト (20) 側に回収する。 Therefore, in the second invention, the circulation operation and the recovery operation of the refrigerant are performed, and in this recovery operation, the compressor (21) is temporarily stopped, and the oil in the pipes (51, 52) is discharged to the heat source unit (20) side. To be collected.
また、第 3の発明は、 第 1又は第 2の発明において、 上記熱源ュニッ ト (20) が圧縮機 (21 ) と熱源側熱交換器 (23) と膨張機構 (24) とを備え、 該熱源ュ ニッ ト (20) は、 液側閉鎖弁 (41 ) を介して液側の配管 (51 ) に接続されると 共に、 ガス側閉鎖弁 (42) を介してガス側の配管 (52) に接続されている。 そ して、 上記第 2の工程は、 液側閉鎖弁 (41 ) を閉鎖した状態で回収運転を開始 し、 該回収運転の終了後にガス側閉鎖弁 (42) を閉鎖する。 In a third aspect, in the first or second aspect, the heat source unit (20) includes a compressor (21), a heat source side heat exchanger (23), and an expansion mechanism (24). The heat source unit (20) is connected to the liquid side pipe (51) via the liquid side shutoff valve (41), and is connected to the gas side pipe (52) via the gas side shutoff valve (42). It is connected to the. In the second step, the recovery operation is started with the liquid-side stop valve (41) closed, and the gas-side stop valve (42) is closed after the completion of the recovery operation.
したがって、 第 3の発明では、 液側閉鎖弁 (41 ) とガス側閉鎖弁 (42) と によって冷媒と油が熱源ユニッ ト (20) に閉じこめられる。 Therefore, in the third invention, the refrigerant and the oil are trapped in the heat source unit (20) by the liquid-side stop valve (41) and the gas-side stop valve (42).
また、第 4の発明は、 第 1又は第 2の発明において、 上記利用ュニッ ト (30) は、 利用側熱交換器 (31 ) と風量の可変な利用側ファン (32) とを備えている。 そして、 上記第 1の工程は、 上記利用側ファン (32) を風量が大きい高風量で 駆動させて循環運転を行う。 In a fourth aspect based on the first or second aspect, the utilization unit (30) includes a utilization-side heat exchanger (31) and a utilization-side fan (32) having a variable air volume. . Then, in the first step, the use side fan (32) is driven at a high air flow with a large air flow to perform a circulation operation.
したがって、 第 4の発明では、 利用側ファン (32) の風量が大きいので、 冷媒の循環が促進される。 Therefore, in the fourth aspect of the present invention, since the air volume of the use side fan (32) is large, the circulation of the refrigerant is promoted.
また、第 5の発明は、 第 1又は第 2の発明において、 上記利用ュニッ ト (30) は、 利用側熱交換器 (31 ) と風量の可変な利用側ファン (32) とを備えている。 そして、 上記第 1の工程は、 上記利用側ファン (32) を風量が小さい低風量で 駆動させて循環運転を行う。
したがって、 第 5の発明では、 利用側ファン (32) の風量が小さいので、 回収運転時の利用ユニッ ト (30) における冷媒が低減される。 In a fifth aspect based on the first or second aspect, the utilization unit (30) includes a utilization-side heat exchanger (31) and a utilization-side fan (32) having a variable air volume. . Then, in the first step, the use side fan (32) is driven at a low air flow with a small air flow to perform a circulation operation. Therefore, in the fifth invention, since the air volume of the use side fan (32) is small, the refrigerant in the use unit (30) during the recovery operation is reduced.
また、 第 6の発明は、 第 1又は第 2の発明において、 上記利用ュニッ ト (30) は、 利用側熱交換器 (31 ) と風量の可変な利用側ファン (32) とを備えている。 そして、 上記第 1の工程は、 循環運転の前半で上記利用側ファン (32) を風量 が大きい高風量で駆動させ、 循環運転の後半で上記利用側ファン (32) を風量 が小さい低風量で駆動させる。 In a sixth aspect based on the first or second aspect, the utilization unit (30) includes a utilization-side heat exchanger (31) and a utilization-side fan (32) having a variable air volume. . In the first step, the use side fan (32) is driven at a high air flow with a large air flow in the first half of the circulation operation, and the use side fan (32) is driven at a low air flow with a small air flow in the second half of the circulation operation. Drive.
したがって、 第 6の発明では、 利用側ファン (32) の高風量によって冷媒 の循環が促進されると同時に、 利用側ファン (32) の低風量によって回収運転 時の利用ユニッ ト (30) における冷媒が低減される。 Therefore, in the sixth invention, the circulation of the refrigerant is promoted by the high air flow of the use side fan (32), and the refrigerant in the use unit (30) at the time of the recovery operation is promoted by the low air flow of the use side fan (32). Is reduced.
また、 第 7の発明は、 第 1又は第 2の発明において、 上記第 1の工程は、 上 記配管 (51 , 52) の高低差に対応して配管 (51 , 52) の高低差が小さいほど循 環運転の時間を短くする。 In a seventh aspect based on the first or second aspect, the first step is such that the height difference between the pipes (51, 52) is small in accordance with the height difference between the pipes (51, 52). The shorter the cycle operation time, the shorter the time.
したがって、 第 7の発明では、 水平配管等では循環運転が短くなる。 Therefore, in the seventh invention, the circulation operation is shortened in a horizontal pipe or the like.
また、 第 8の発明は、 第 1又は第 2の発明において、 上記第 1の工程は、 上 記配管 (51 , 52) の長さに対応して配管 (51 , 52) の長さが短いほど循環運転 の時間を短くする。 In an eighth aspect based on the first or second aspect, the first step is such that the length of the pipe (51, 52) is short corresponding to the length of the pipe (51, 52). The shorter the circulation operation time, the shorter the time.
したがって、 第 8の発明では、 配管 (51 , 52) 長が短い場合、 循環運転が 短くなる。 Therefore, in the eighth invention, when the length of the pipe (51, 52) is short, the circulation operation is short.
また、第 9の発明は、 第 1又は第 2の発明において、 上記熱源ュニッ ト (20) は、 圧縮機 (21 ) と熱源側熱交換器 (23) と膨張機構 (24) とを備えている。 そして、 上記熱源ユニッ ト (20) には、 圧縮機 (21 ) の吐出側又は正サイクル における膨張機構 (24) の下流側に油分離器 (60) が設けられている。 In a ninth aspect, in the first or second aspect, the heat source unit (20) includes a compressor (21), a heat source side heat exchanger (23), and an expansion mechanism (24). I have. The heat source unit (20) is provided with an oil separator (60) on the discharge side of the compressor (21) or on the downstream side of the expansion mechanism (24) in the normal cycle.
したがって、 第 9の発明では、 油分離器 (60) で油が回収されるので、 回 収運転の制御の自由度が向上する。 Therefore, in the ninth invention, the oil is recovered by the oil separator (60), so that the degree of freedom in controlling the recovery operation is improved.
一発明の効果一 Effect of one invention
したがって、 本発明によれば、 冷媒の循環運転と回収運転とを行うようにし たために、 配管 (51, 52) の油を熱源ユニッ ト (20) 側に確実かつ容易に回収
δ Therefore, according to the present invention, since the refrigerant circulation operation and the recovery operation are performed, the oil in the pipes (51, 52) is reliably and easily recovered to the heat source unit (20) side. δ
することができる。 can do.
この結果、 既存の C F C系冷媒又は H C F C系冷媒の装置に用いられていた 冷凍機油の配管 (51, 52) における残留量を許容値以下にすることができる。 したがって、 既存の C F C系冷媒又は H C F C系冷媒の装置の配管 (51 , 52) を洗浄装置等で洗浄することがなく、 新設の H F C系冷媒又は H C系冷媒の装置 を既存の配管 (51, 52) に接続して設置することができる。 As a result, the residual amount of the refrigerating machine oil used in the existing CFC-based or HFCC-based refrigerant devices in the pipes (51, 52) can be reduced to an allowable value or less. Therefore, the pipes (51, 52) of the existing CFC-based or HCFC-based refrigerant equipment do not need to be washed with a cleaning device, etc., and the newly installed HFC-based or HC-based refrigerant equipment can be connected to the existing piping (51, 52). ) Can be installed.
また、 油回収装置等を設ける必要がないので、 部品点数の増加を防止するこ とができる。 Also, since there is no need to provide an oil recovery device or the like, an increase in the number of parts can be prevented.
特に、 第 1の発明によれば、 圧縮機 (21 ) を継続して駆動したまま循環運 転と回収運転を連続して行うようにしたために、 冷媒と油が相溶した状態でこの 冷媒及び油を熱源ユニッ ト (20) 側に回収することができる。 この結果、 油の 回収をより確実にかつ迅速に行うことができる。 In particular, according to the first invention, the circulation operation and the recovery operation are continuously performed while the compressor (21) is continuously driven. Oil can be collected on the heat source unit (20) side. As a result, oil recovery can be performed more reliably and promptly.
また、 第 2の発明によれば、 圧縮機 (21 ) を一旦停止して回収運転を行う 場合であっても、冷媒と油が相溶した状態でこの冷媒及び油を熱源ュニッ ト (20) 側に回収することができる。 According to the second invention, even when the compressor (21) is temporarily stopped to perform the recovery operation, the refrigerant and the oil are mixed with the heat source unit (20) in a state where the refrigerant and the oil are dissolved. Can be collected on the side.
また、 第 3の発明によれば、 液側閉鎖弁 (41 ) 及びガス側閉鎖弁 (42) を 設けているので、 冷媒及び油を確実に熱源ユニッ ト (20) に封じ込めることが できる。 Further, according to the third aspect, since the liquid-side stop valve (41) and the gas-side stop valve (42) are provided, the refrigerant and the oil can be reliably sealed in the heat source unit (20).
また、 第 4の発明によれば、 利用側ファン (32) の風量を大きい高風量に 設定するので、 利用側熱交換器 (31 ) における熱交換を促進させて冷媒循環を 増大させることができ、 冷媒と油の相溶を迅速に行わせることができる。 この結 果、 油の回収を確実に行うことができる。 Further, according to the fourth invention, since the air volume of the use side fan (32) is set to a large high air volume, heat exchange in the use side heat exchanger (31) can be promoted to increase the refrigerant circulation. However, the refrigerant and the oil can be rapidly dissolved. As a result, the oil can be reliably recovered.
また、 第 5の発明によれば、 利用側ファン (32) の風量を小さい低風量に 設定するので、冷媒循環量が少ないことから、循環運転の終期において、配管(51, 52) と利用ユニッ ト (30) における冷媒量及び油量を少なくすることができる。 この結果、 油の回収を確実に行うことができる。 According to the fifth aspect of the present invention, since the flow rate of the use side fan (32) is set to a small and low flow rate, the amount of refrigerant circulating is small, so that at the end of the circulation operation, the pipes (51, 52) and the use unit are not used. (30) The amount of refrigerant and oil in (30) can be reduced. As a result, the oil can be reliably collected.
また、 第 6の発明によれば、 循環運転において、 前半の利用側ファン (32) の風量を高風量に設定し、 後半の利用側ファン (32) の風量を低風量に設定す るので、 循環運転の前半では、 冷媒循環を増大して冷媒と油の相溶を促進させる
一方、 後半では、 配管 (51 , 52) と利用ユニッ ト (30) における冷媒量及び油 量を少なくすることができる。 この結果、 油の回収を確実に行うことができる。 According to the sixth aspect of the invention, in the circulation operation, the air volume of the first-side usage-side fan (32) is set to a high air volume, and the air volume of the second-half usage-side fan (32) is set to a low air volume. In the first half of circulation operation, increase refrigerant circulation to promote compatibility of refrigerant and oil On the other hand, in the latter half, the amount of refrigerant and oil in the pipes (51, 52) and the utilization unit (30) can be reduced. As a result, the oil can be reliably collected.
また、 第 7の発明によれば、 第 1の工程の循環運転を配管 (51 , 52) の高 低差に対応して該配管 (51, 52) の高低差が小さいほど循環運転の時間を短く するので、 水平配管などの場合、 循環運転の時間を短くすることができる。 According to the seventh aspect of the invention, the circulation operation in the first step is performed in accordance with the height difference of the pipes (51, 52) as the height difference of the pipes (51, 52) is smaller. Since the length is shortened, the time for circulation operation can be shortened in the case of horizontal piping and the like.
また、 第 8の発明によれば、 第 1の工程の循環運転を配管 (51 , 52) の長 さに対応して該配管 (51, 52) の長さが短いほど循環運転の時間を短くするの で、 配管長が短い場合、 循環運転の時間を短くすることができる。 According to the eighth invention, the circulation operation of the first step is performed in accordance with the length of the pipe (51, 52), and the shorter the length of the pipe (51, 52), the shorter the time of the circulation operation. Therefore, when the pipe length is short, the time of the circulation operation can be shortened.
また、 第 9の発明によれば、 油分離器 (60) を設けるので、 熱源ユニッ ト (20) と液側の配管 (51 ) の閉鎖時期を回収運転の開始前に限る必要がない。 つまり、 上記油分離器 (60) によって油が回収されるので、 回収運転の開始時 に多量の油が液側の配管 (51 ) に流出することがない。 この結果、 上記閉鎖時 期の自由度が向上する。 図面の簡単な説明 Further, according to the ninth aspect, since the oil separator (60) is provided, it is not necessary to limit the closing time of the heat source unit (20) and the liquid side pipe (51) before the start of the recovery operation. That is, since the oil is collected by the oil separator (60), a large amount of oil does not flow out to the liquid side pipe (51) at the start of the collecting operation. As a result, the degree of freedom of the closing time is improved. BRIEF DESCRIPTION OF THE FIGURES
図 1は、 本発明の構成を示す空気調和装置の冷媒回路図である。 FIG. 1 is a refrigerant circuit diagram of an air conditioner illustrating a configuration of the present invention.
図 2は、 液側閉鎖弁の閉鎖時期による残油量を示す特性図である。 FIG. 2 is a characteristic diagram showing the residual oil amount according to the closing timing of the liquid side closing valve.
図 3は、 事前運転の長さによる残油量を示す特性図である。 FIG. 3 is a characteristic diagram showing the residual oil amount according to the length of the preliminary operation.
図 4は、 本発明の実施形態 1の油回収方法を示すフロー図である。 FIG. 4 is a flowchart showing the oil recovery method according to the first embodiment of the present invention.
図 5は、 本発明の実施形態 2の油回収方法を示すフロー図である。 FIG. 5 is a flowchart showing an oil recovery method according to Embodiment 2 of the present invention.
図 6は、 本発明の実施形態 3の油回収方法を示すフロー図である。 FIG. 6 is a flowchart showing an oil recovery method according to Embodiment 3 of the present invention.
図 7は、 本発明の実施形態 4の油回収方法を示すフロー図である。 発明を実施するための最良の形態 FIG. 7 is a flowchart showing an oil recovery method according to Embodiment 4 of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION
一実施形態 1一 One embodiment 11
以下、 本発明の実施形態 1を図面に基づいて詳細に説明する。 Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings.
図 1に示すように、 本実施形態の冷凍装置は、 冷房運転と暖房運転とを切り 換えて行う空気調和装置 (10) である。 As shown in FIG. 1, the refrigeration apparatus of the present embodiment is an air conditioner (10) that switches between a cooling operation and a heating operation.
上記空気調和装置 (10) は、 冷媒が循環して蒸気圧縮式冷凍サイクルを行
ぅ冷媒回路 (1A) を備えている。 該冷媒回路 (1A) は、 熱源ユニッ トである室 外ユニッ ト (20) と、 利用ユニッ トである室内ユニッ ト (30) とが配管である 液配管 (51 ) とガス配管 (52) とによって接続されて構成されている。 In the air conditioner (10), the refrigerant circulates and performs a vapor compression refrigeration cycle. ぅ Equipped with a refrigerant circuit (1A). The refrigerant circuit (1A) includes a liquid pipe (51), a gas pipe (52), and an outdoor unit (20), which is a heat source unit, and an indoor unit (30), which is a use unit. It is configured to be connected by.
上記室外ユニッ ト (20) は、 圧縮機 (21 ) と四路切換弁 (22) と熱源側熱 交換器でる室外熱交換器 (23) と膨張機構である電動膨張弁 (24) とを備えて いる。 そして、 該圧縮機 (21 ) と四路切換弁 (22) と室外熱交換器 (23) と電 動膨張弁 (24) とは、 冷媒配管である室外配管 (2a) によって順に接続されて いる。 尚、 上記室外熱交換器 (23) には、 熱源側ファンである室外ファン (25) が設けられている。 The outdoor unit (20) includes a compressor (21), a four-way switching valve (22), an outdoor heat exchanger (23) as a heat source side heat exchanger, and an electric expansion valve (24) as an expansion mechanism. ing. The compressor (21), the four-way switching valve (22), the outdoor heat exchanger (23), and the electric expansion valve (24) are sequentially connected by an outdoor pipe (2a) that is a refrigerant pipe. . The outdoor heat exchanger (23) is provided with an outdoor fan (25) which is a heat source side fan.
上記室内ユニッ ト (30) は、 利用側熱交換器である室内熱交換器 (31 ) を 備え、 該室内熱交換器 (31 ) には冷媒配管である室内配管 (3a) が接続されて いる。 尚、 上記室内熱交換器 (31 ) は、 利用側ファンである室内ファン (32) が設けられている。 The indoor unit (30) includes an indoor heat exchanger (31) as a use side heat exchanger, and an indoor pipe (3a) as a refrigerant pipe is connected to the indoor heat exchanger (31). . The indoor heat exchanger (31) is provided with an indoor fan (32) that is a use-side fan.
上記室外ユニッ ト (20) における液側の室外配管 (2a) の端部、 つまり、 室外配管 (2a) の電動膨張弁 (24) 側の端部は、 液側の閉鎖機構である液側閉 鎖弁 (41 ) が設けられると共に、 フレア接続等の接続具 (26) を介して液配管 (51 ) の一端が接続されている。 上記室外ユニッ ト (20) におけるガス側の室 外配管 (2a) の端部、 つまり、 室外配管 (2a) の四路切換弁 (22) 側の端部は、 ガス側の閉鎖機構であるガス側閉鎖弁 (42) が設けられると共に、 フレア接続 等の接続具 (27) を介してガス配管 (52) の一端が接続されている。 The end of the liquid side outdoor pipe (2a) in the outdoor unit (20), that is, the end of the outdoor pipe (2a) on the side of the electric expansion valve (24) is a liquid side closing mechanism which is a liquid side closing mechanism. A chain valve (41) is provided, and one end of a liquid pipe (51) is connected via a connector (26) such as a flare connection. The end of the outdoor pipe (2a) on the gas side in the outdoor unit (20), that is, the end of the outdoor pipe (2a) on the four-way switching valve (22) side is a gas-side closing mechanism. A side stop valve (42) is provided, and one end of a gas pipe (52) is connected via a connector (27) such as a flare connection.
上記室内ユニッ ト (30) における液側の室内配管 (3a) の端部は、 フレア 接続等の接続具 (33) を介して液配管 (51 ) の一端が接続されている。 上記室 内ユニッ ト (30) におけるガス側の室内配管 (3a) の端部は、 フレア接続等の 接続具 (34) を介してガス配管 (52) の他端が接続されている。 One end of the liquid pipe (51) is connected to an end of the liquid side indoor pipe (3a) in the indoor unit (30) via a connector (33) such as a flare connection. The other end of the gas pipe (52) is connected to the end of the indoor pipe (3a) on the gas side in the indoor unit (30) via a connector (34) such as a flare connection.
上記冷媒回路 (1A) は、 四路切換弁 (22) の切換によって正サイクルであ る冷房サイクルの運転と逆サイクルである暖房サイクルの運転とに切り換わるよ うに構成されている。 つまり、 上記四路切換弁 (22) が図 1の実線側に切り換 わると、 上記冷媒回路 (1A) は、 室外ユニッ ト (20) で冷媒が凝縮する正サイ クルの運転である冷房サイクルの運転で冷媒が循環する。 また、 上記四路切換弁
(22) が図 1の破線側に切り換わると、 上記冷媒回路 (1A) は、 室内ユニッ ト (30) で冷媒が凝縮する逆サイクルの運転である暖房サイクルの運転で冷媒が 循環する。 The refrigerant circuit (1A) is configured to switch between a cooling cycle operation, which is a normal cycle, and a heating cycle operation, which is a reverse cycle, by switching the four-way switching valve (22). That is, when the four-way switching valve (22) is switched to the solid line side in FIG. 1, the refrigerant circuit (1A) operates in a cooling cycle in which the refrigerant condenses in the outdoor unit (20). The refrigerant circulates during the operation. In addition, the above four-way switching valve When (22) switches to the broken line side in FIG. 1, the refrigerant circuit (1A) circulates refrigerant in the heating cycle operation, which is the reverse cycle operation in which the refrigerant condenses in the indoor unit (30).
上記正サイクルの運転の一例として冷房運転がある。 この冷房運転は、 冷媒 が圧縮機 (21 ) から吐出して室外熱交換器 (23) で凝縮した後、 電動膨張弁 (24) で膨張し、 室内熱交換器 (31 ) で蒸発して圧縮機 (21 ) に戻る循環を繰り返す。 一方、 上記逆サイクルの運転の一例として暖房運転がある。 この暖房運転は、 冷 媒が圧縮機 (21 ) から吐出して室内熱交換器 (31 ) で凝縮した後、 電動膨張弁 (24) で膨張し、 室外熱交換器 (23) で蒸発して圧縮機 (21 ) に戻る循環を繰 り返す。 一油回収方法一 An example of the operation in the normal cycle is a cooling operation. In this cooling operation, refrigerant is discharged from the compressor (21), condensed in the outdoor heat exchanger (23), expanded by the electric expansion valve (24), and evaporated and compressed in the indoor heat exchanger (31). The circulation returning to the machine (21) is repeated. On the other hand, there is a heating operation as an example of the reverse cycle operation. In this heating operation, the refrigerant is discharged from the compressor (21), condensed in the indoor heat exchanger (31), expanded by the electric expansion valve (24), and evaporated in the outdoor heat exchanger (23). The circulation returning to the compressor (21) is repeated. One oil recovery method
次に、 上述した空気調和装置 (10) における冷凍機油である油の回収方法 について説明する。 つまり、 既設の空気調和装置 (10) を新設の空気調和装置 ( 10) に交換する場合、 液配管 (51 ) 及びガス配管 (52) を再利用する場合が ある。 その際、 上記液配管 (51 ) 及びガス配管 (52) に付着した冷凍機油を回 収する必要がある。 Next, a method of recovering the oil that is the refrigerating machine oil in the above-described air conditioner (10) will be described. In other words, when replacing the existing air conditioner (10) with a new air conditioner (10), the liquid pipe (51) and the gas pipe (52) may be reused. At that time, it is necessary to collect the refrigerating machine oil attached to the liquid pipe (51) and the gas pipe (52).
そこで、 既設の空気調和装置 (10) において、 冷凍機油である油を圧縮機 (21 ) などの室外ユニッ ト (20) 側に回収する。 この油回収方法は、 基本的に、 冷媒を冷媒回路 (1A) 内で循環させて冷媒と油とを充分に相溶させる循環運転 である事前運転を行う第 1の工程と、 冷媒と油とが充分に相溶した状態で冷媒と 油とを室外ユニッ ト (20) に回収する回収運転であるポンプダウン運転を行う 第 2の工程とを備えている。 Therefore, in the existing air conditioner (10), the oil that is the refrigerating machine oil is collected in the outdoor unit (20) such as the compressor (21). This oil recovery method basically includes a first step of performing a preliminary operation, which is a circulation operation in which the refrigerant is circulated in the refrigerant circuit (1A) so that the refrigerant and the oil are sufficiently compatible with each other; And a second step of performing a pump-down operation, which is a recovery operation for recovering the refrigerant and the oil to the outdoor unit (20) in a state where they are sufficiently compatible.
この油回収方法は、 図 4に示すように、 先ず、 ステップ S T 1において、 冷 媒回路 (1A) を冷房運転モードにする。 つまり、 四路切換弁 (22) を図 1の実 線側に切り換え、 正サイクルである冷房サイクルの状態に冷媒回路 (1A) を設 定する。 更に、 室内の温度設定値を最低値にし、 圧縮機 (21 ) が連続して駆動 するようにする。 In this oil recovery method, as shown in FIG. 4, first, in step ST1, the refrigerant circuit (1A) is set to the cooling operation mode. That is, the four-way switching valve (22) is switched to the solid line side in FIG. 1, and the refrigerant circuit (1A) is set to the state of the cooling cycle, which is the normal cycle. Further, the temperature set value in the room is set to the lowest value so that the compressor (21) is driven continuously.
その後、 ステップ S T 2に移り、 第 1の工程を開始し、 冷房サイクルの運転
である冷房運転 (循環運転) を開始する。 続いて、 ステップ S T 3に移り、 上記 冷房運転の運転時間の計数を開始し、 ステップ S T 4に移り、 圧縮機 (21) が 停止したか否かを判定する。 該圧縮機 (21) が連続して駆動している場合、 ス テツプ S T 4からステップ S T 5に移り、 上記冷房運転が所定時間行われた否か を判定し、 所定時間が経過するまで上記ステップ S T 4に戻り、 上述の動作を繰 り返し、 圧縮機 (21) が連続駆動した事前運転を行う。 Then, move to step ST2, start the first process, and operate the cooling cycle. Start cooling operation (circulation operation). Subsequently, the process proceeds to step ST3 to start counting the operation time of the cooling operation, and proceeds to step ST4 to determine whether or not the compressor (21) has stopped. If the compressor (21) is continuously driven, the process proceeds from step ST4 to step ST5, where it is determined whether or not the cooling operation has been performed for a predetermined time. Returning to ST4, the above operation is repeated, and the compressor (21) performs a preliminary operation in which the compressor (21) is continuously driven.
このステップ S T 5の所定時間は、 例えば、 3 0分に設定されている。 つま り、 上記冷房運転を開始すると、 冷媒が冷媒回路 (1A) を循環することになる が、 冷媒と冷凍機油とが相溶するためには、 冷媒が冷媒回路 (1A) を所定時間 循環する必要がある。 そこで、 上記冷媒と冷凍機油が相溶するように、 例えば、 30分の冷房運転を行う。 The predetermined time of step ST5 is set to, for example, 30 minutes. That is, when the cooling operation is started, the refrigerant circulates in the refrigerant circuit (1A). However, in order for the refrigerant and the refrigerating machine oil to be compatible, the refrigerant circulates in the refrigerant circuit (1A) for a predetermined time. There is a need. Thus, for example, a cooling operation for 30 minutes is performed so that the refrigerant and the refrigerating machine oil are compatible.
その後、 上記所定時間が経過し、 圧縮機 (21) が連続して所定時間駆動す ると、 ステップ S T 5の判定が YE Sとなってステップ S T 6に移り、 冷房運転 を一旦停止し、第 1の工程が終了すると同時に、 第 2の工程が開始する。 つまり、 上記圧縮機 (21) の連続駆動を一旦停止する。 Thereafter, when the predetermined time has elapsed and the compressor (21) is continuously driven for the predetermined time, the determination in step ST5 becomes YES, and the process proceeds to step ST6, in which the cooling operation is temporarily stopped, and As soon as the first step is completed, the second step starts. That is, the continuous driving of the compressor (21) is temporarily stopped.
その後、 ステップ S T 7に移り、 液側閉鎖弁 (41) を全閉とし、 例えば、 手動で液側閉鎖弁 (41) を閉じ、 室外ユニッ ト (20) の室外配管 (2a) と液配 管 (51) との間を閉鎖する。 その後、 ステップ S T 8に移り、 上記圧縮機 (21) の停止時間が所定時間以上であるか否かを判定する。 つまり、 上記圧縮機 (21) の停止時間が長いと、 冷凍機油が液滴となるからである。 Thereafter, the process proceeds to step ST7, where the liquid-side shutoff valve (41) is fully closed. For example, the liquid-side shutoff valve (41) is manually closed, and the outdoor piping (2a) of the outdoor unit (20) and the liquid piping are connected. (51) is closed. Thereafter, the process proceeds to step ST8, where it is determined whether or not the stop time of the compressor (21) is longer than a predetermined time. That is, if the stop time of the compressor (21) is long, the refrigerating machine oil becomes droplets.
したがって、 上記圧縮機 (21) の停止時間が、 例えば、 30分以上となる と、 上記ステップ ST 8の判定が YE Sとなってステップ ST 2に戻り、 循環運 転である冷房運転を再度やり直す。 Therefore, if the stop time of the compressor (21) becomes, for example, 30 minutes or more, the determination in step ST8 becomes YES, the process returns to step ST2, and the cooling operation as the circulating operation is performed again. .
—方、 上記上記圧縮機 (21) の停止時間が所定時間内であると、 上記ステ ップ S T 8の判定が NOとなってステップ S T 9に移り、 冷媒回路 (1A) が正 サイクルのままで回収運転である冷房運転を開始する。 つまり、 本実施形態の空 気調和装置 (10) はポンプダウン機能を有しないものの、 上記液側閉鎖弁 (41) を閉じているので、 冷房運転の開始によってポンプダウン運転が開始されたこと となる。
続いて、 ステップ S T 1 0に移り、 上記ポンプダウン運転が所定時間行われ たか否かを判定し、 所定時間が経過するまで上記ポンプダウン運転を行い、 所定 時間が経過すると、 ステップ S T 1 1に移り、 ガス側閉鎖弁 (42) を全閉とし、 ステップ S T 1 2に移り、 冷房運転を停止し、 つまり、 ポンプダウン運転である 冷房運転を停止して第 2の工程を終了する。 この冷房運転によって冷凍機油が室 外ユニッ ト (20) に封じ込められることになる。 On the other hand, if the stop time of the compressor (21) is within the predetermined time, the determination in step ST8 is NO and the process proceeds to step ST9, where the refrigerant circuit (1A) remains in the normal cycle. Starts the cooling operation which is the recovery operation. That is, although the air-conditioning apparatus (10) of the present embodiment does not have a pump-down function, since the liquid-side stop valve (41) is closed, the pump-down operation is started by the start of the cooling operation. Become. Subsequently, the process proceeds to step ST10, where it is determined whether or not the pump-down operation has been performed for a predetermined time, and the pump-down operation is performed until the predetermined time has elapsed. When the predetermined time has elapsed, the process proceeds to step ST11. Then, the gas side shut-off valve (42) is fully closed, and the process proceeds to step ST12 to stop the cooling operation. That is, the cooling operation, which is the pump-down operation, is stopped, and the second process ends. By this cooling operation, the refrigerating machine oil is confined in the outdoor unit (20).
その後、 第 3の工程に移り、 接続具 (26, 27, 33 , 34) から室外ユニッ ト (20) 及び室内ユニッ ト (30) を液配管 (51 ) 及びガス配管 (52) より取り外 す。 そして、 新たな室外ユニッ ト (20) 及び室内ユニッ ト (30) を既設の液配 管 (51 ) 及びガス配管 (52) に接続して新設の空気調和装置 (10) の設置が完 了する。 After that, move to the third step, and remove the outdoor unit (20) and indoor unit (30) from the connecting pipes (26, 27, 33, 34) from the liquid pipe (51) and gas pipe (52). . Then, the new outdoor unit (20) and the new indoor unit (30) are connected to the existing liquid piping (51) and gas piping (52), and the installation of the new air conditioner (10) is completed. .
尚、 上記ステップ S T 4において、循環運転である冷房運転中に圧縮機(21 ) が停止すると、 冷媒と油の相溶が促進されないので、 ステップ S T 1 3に移り、 冷房運転の時間計数をリセットしてステップ S T 3に戻り、冷房運転を継続する。 In step ST4, if the compressor (21) stops during the cooling operation which is the circulation operation, the compatibility of the refrigerant and the oil is not promoted. Therefore, the process proceeds to step ST13 to reset the time count of the cooling operation. And return to step ST3 to continue the cooling operation.
また、 上記循環運転である冷房運転と、 回収運転である冷房運転において、 室内ファン (32) は、 高風量で運転する。 例えば、 上記室内ファン (32) の風 量が、 強、 中、 弱、 微風の 4段階に設定することができる場合、 最大風量の 「強」 又は大きい風量の 「中」 などに設定する。 この結果、 室内熱交換器 (31 ) にお ける熱交換を促進させて冷媒循環を増大させることができる。 In addition, in the cooling operation as the circulation operation and the cooling operation as the recovery operation, the indoor fan (32) operates at a high air flow. For example, if the air volume of the indoor fan (32) can be set to four levels: strong, medium, low, and light, set the maximum air volume to “strong” or a large air volume to “medium”. As a result, heat exchange in the indoor heat exchanger (31) can be promoted to increase the refrigerant circulation.
また、 逆に、 上記循環運転において、 室內ファン (32) の風量を最小風量 の 「微風」 又は小さい風量の 「弱」 などに設定するようにしてもよい。 この場合、 冷媒循環量が少ないので、 循環運転における終期において、 液配管 (51 ) 及び ガス配管 (52) と室内ユニッ ト (30) における冷媒量及び油量を少なくするこ とができる。 Conversely, in the above-mentioned circulation operation, the air volume of the room / fan (32) may be set to “minimum air volume” of the minimum air volume or “weak” of the small air volume. In this case, since the refrigerant circulation amount is small, the refrigerant amount and the oil amount in the liquid pipe (51), the gas pipe (52), and the indoor unit (30) can be reduced at the end of the circulation operation.
更に、 上記循環運転において、 前半は、 上記室内ファン (32) の風量を最 大風量の 「強」 又は大きい風量の 「中」 などに設定し、 後半は、 室内ファン (32) の風量を最小風量の 「微風」 又は小さい風量の 「弱」 などに設定するようにして もよい。 この場合、 循環運転の前半では、 冷媒循環を増大して冷媒と油の相溶を 促進させる一方、 後半では、 液配管 (51 ) 及びガス配管 (52) と室内ユニッ ト
(30) における冷媒量及び油量を少なくすることができる。 一実施形態 1の効果一 Furthermore, in the above-mentioned circulation operation, in the first half, the air volume of the indoor fan (32) is set to “strong” of the maximum air volume or “medium” of the large air volume, and in the second half, the air volume of the indoor fan (32) is minimized. The air volume may be set to “light wind” or a small air volume “weak”. In this case, in the first half of the circulation operation, the refrigerant circulation is increased to promote the compatibility between the refrigerant and the oil, while in the second half, the liquid pipe (51) and the gas pipe (52) are connected to the indoor unit. (30) The amount of refrigerant and the amount of oil in (30) can be reduced. Effect of Embodiment 1
以上のように、 本実施形態によれば、 冷媒の循環運転と回収運転とを行うよ うにしたために、 液配管 (51 ) 及びガス配管 (52) の油を室外ユニッ ト (20) 側に確実かつ容易に回収することができる。 As described above, according to this embodiment, since the circulation operation and the recovery operation of the refrigerant are performed, the oil in the liquid pipe (51) and the gas pipe (52) is reliably supplied to the outdoor unit (20) side. And it can be easily collected.
この結果、 既存の C F C系冷媒又は H C F C系冷媒の装置に用いられていた 冷凍機油の液配管 (51 ) 及びガス配管 (52) における残留量を許容値以下にす ることができる。 したがって、 既存の C F C系冷媒又は H C F C系冷媒の装置の 液配管 (51 ) 及びガス配管 (52) を洗浄装置等で洗浄することがなく、 新設の H F C系冷媒又は H C系冷媒の装置を既存の液配管 (51 ) 及びガス配管 (52) に接続して設置することができる。 As a result, the residual amount of the refrigerating machine oil used in the existing CFC-based refrigerant or HFCC-based refrigerant in the liquid pipe (51) and the gas pipe (52) can be reduced to an allowable value or less. Therefore, the liquid pipe (51) and gas pipe (52) of the existing CFC-based or HCFC-based refrigerant system need not be cleaned with a cleaning device or the like. It can be connected to the liquid pipe (51) and the gas pipe (52).
また、 油回収装置等を設ける必要がないので、 部品点数の増加を防止するこ とができる。 Also, since there is no need to provide an oil recovery device or the like, an increase in the number of parts can be prevented.
また、 上記液側閉鎖弁 (41 ) 及びガス側閉鎖弁 (42) を設けているので、 冷媒及び油を確実に室外ユニッ ト (20) に封じ込めることができる。 Further, since the liquid-side shut-off valve (41) and the gas-side shut-off valve (42) are provided, the refrigerant and the oil can be reliably sealed in the outdoor unit (20).
また、 上記室内ファン (32) の風量を大きい高風量に設定すると、 室内熱 交換器 (31 ) における熱交換を促進させて冷媒循環を増大させることができ、 冷媒と油の相溶を迅速に行わせることができる。 この結果、 油の回収を確実に行 うことができる。 Further, when the air volume of the indoor fan (32) is set to a large high air volume, the heat exchange in the indoor heat exchanger (31) can be promoted to increase the circulation of the refrigerant, and the compatibility of the refrigerant and the oil can be rapidly increased. Can be done. As a result, the oil can be reliably recovered.
また、 上記室内ファン (32) の風量を小さい低風量に設定すると、 冷媒循 環量が少ないので、 循環運転の終期において、 液配管 (51 ) 及びガス配管 (52) と室内ユニッ ト (30) における冷媒量及び油量を少なくすることができる。 こ の結果、 油の回収を確実に行うことができる。 If the air volume of the indoor fan (32) is set to a small low air volume, the amount of refrigerant circulated is small, so that at the end of circulation operation, the liquid pipe (51) and gas pipe (52) and the indoor unit (30) , The amount of refrigerant and the amount of oil can be reduced. As a result, the oil can be reliably recovered.
また、 上記循環運転において、 前半の室内ファン (32) の風量を高風量に 設定し、 後半の室内ファン (32) の風量を低風量に設定すると、 循環運転の前 半では、 冷媒循環を増大して冷媒と油の相溶を促進させる一方、 後半では、 液配 管 (51 ) 及びガス配管 (52) と室内ユニッ ト (30) における冷媒量及び油量を 少なくすることができる。 この結果、 油の回収を確実に行うことができる。
一実施形態 2— Also, in the above-mentioned circulation operation, if the air volume of the first half indoor fan (32) is set to a high air volume and the air volume of the second half indoor fan (32) is set to a low air volume, the refrigerant circulation will increase in the first half of the circulation operation. In the latter half, the amount of refrigerant and oil in the liquid pipe (51), the gas pipe (52) and the indoor unit (30) can be reduced. As a result, the oil can be reliably collected. Embodiment 2—
次に、 本発明の実施形態 2を図面に基づいて詳細に説明する。 Next, a second embodiment of the present invention will be described in detail with reference to the drawings.
図 5に示すように、 本実施形態は、 実施形態 1がポンプダウン機能を有しな い空気調和装置 (10) であったのに代わり、 ポンプダウン機能を有する空気調 和装置 (10) とした場合である。 As shown in FIG. 5, in the present embodiment, instead of the air conditioner (10) having no pump-down function in the first embodiment, an air conditioner (10) having a pump-down function is provided. This is the case.
この空気調和装置 (10) における油回収方法は、 実施形態 1における図 4 のステップ S T 9が図 5のステップ S T 2 9に代わったもので、 その他は、 実施 形態 1 と同じである。 The oil recovery method of the air conditioner (10) is the same as that of the first embodiment except that step ST9 in FIG. 4 in the first embodiment replaces step ST29 in FIG.
つまり、 先ず、 四路切換弁 (22) を図 1の実線側に切り換え、 正サイクル である冷房サイクルの状態に冷媒回路 (1A) を設定し、 更に、 室内の温度設定 値を最低値に設定する (ステップ S T 2 1 )。 That is, first, the four-way switching valve (22) is switched to the solid line side in Fig. 1, the refrigerant circuit (1A) is set in the cooling cycle state, which is the normal cycle, and the indoor temperature set value is set to the lowest value. (Step ST 21).
その後、 第 1の工程を開始し、 冷房サイクルの運転である冷房運転 (循環運 転) を開始してこの冷房運転の運転時間を計数し、 圧縮機 (21 ) が連続して駆 動している場合、 所定時間が経過するまで上述の動作を繰り返し、 冷媒を循環さ せる (ステップ S T 2 2〜ステップ S T 2 5 )。 After that, the first step is started, the cooling operation (circulation operation), which is the operation of the cooling cycle, is started, the operation time of this cooling operation is counted, and the compressor (21) is driven continuously. If so, the above operation is repeated until a predetermined time elapses, and the refrigerant is circulated (step ST22 to step ST25).
その後、 上記所定時間が経過し、 圧縮機 (21 ) が連続して所定時間駆動す ると、 圧縮機 (21 ) の連続駆動を一旦停止して冷房運転をー且停止し、 第 1の 工程が終了すると同時に、 第 2の工程が開始する (ステップ S T 2 6 )。 Thereafter, when the predetermined time has elapsed and the compressor (21) has been continuously driven for a predetermined time, the continuous driving of the compressor (21) is temporarily stopped to stop the cooling operation, and the first step is performed. At the same time, the second process starts (step ST26).
その後、 液側閉鎖弁 (41 ) を全閉と し、 上記圧縮機 (21 ) の停止時間が所 定時間以上であるか否かを判定し、 上記圧縮機 (21 ) の停止時間が、 例えば、 3 0分以上となると、 循環運転である冷房運転を再度やり直す (ステップ S T 2 7及びステップ S T 2 8 )。 Thereafter, the liquid-side stop valve (41) is fully closed, and it is determined whether or not the stop time of the compressor (21) is longer than a predetermined time. After 30 minutes, the cooling operation, which is the circulation operation, is restarted (step ST27 and step ST28).
一方、 上記上記圧縮機 (21 ) の停止時間が所定時間内であると、 ステップ S T 2 9において、 ポンプダウン運転スィツチである冷媒回収運転スィツチを O Nする。 On the other hand, if the stop time of the compressor (21) is within the predetermined time, in step ST29, the refrigerant recovery operation switch, which is the pump down operation switch, is turned ON.
続いて、 上記ポンプダウン運転である冷媒回収運転が所定時間行われるのを 待ち、 所定時間が経過すると、 ガス側閉鎖弁 (42) を全閉とし、 冷媒回収運転 を停止して第 2の工程を終了する (ステップ S T 3 0〜ステップ S T 3 2 )。 こ
の冷媒回収運転によって冷凍機油が室外ユニッ ト (20) に封じ込められること になる。 Subsequently, the system waits for the refrigerant recovery operation, which is the pump-down operation, to be performed for a predetermined time. After the predetermined time has elapsed, the gas-side shut-off valve (42) is fully closed, the refrigerant recovery operation is stopped, and the second process is performed. (Step ST30 to Step ST32). This By the refrigerant recovery operation, the refrigerating machine oil is confined in the outdoor unit (20).
その後、 第 3の工程に移り、 接続具 (26, 27, 33, 34) から室外ユニッ ト After that, the process moves to the third step, where the outdoor unit is connected through the fittings (26, 27, 33, 34).
(20) 及び室内ユニッ ト (30) を液配管 (51 ) 及びガス配管 (52) より取り外 す。 そして、 新たな室外ユニッ ト (20) 及び室内ユニッ ト (30) を既設の液配 管 (51 ) 及びガス配管 (52) に接続して新設の空気調和装置 (10) の設置が完 了する。 Remove (20) and the indoor unit (30) from the liquid pipe (51) and gas pipe (52). Then, the new outdoor unit (20) and the new indoor unit (30) are connected to the existing liquid piping (51) and gas piping (52), and the installation of the new air conditioner (10) is completed. .
尚、 上記ステップ S T 2 4において、 循環運転である冷房運転中に圧縮機 It should be noted that in step ST24, the compressor is operated during the cooling operation, which is a circulation operation.
(21 ) が停止すると、 ステップ S T 3 3に移り、 冷房運転の時間計数をリセッ トしてステップ S T 2 3に戻り、 冷房運転を継続する。 その他の構成、 作用及び 効果は、 実施形態 1と同様である。 When (21) stops, the process moves to step ST33, resets the time count of the cooling operation, returns to step ST23, and continues the cooling operation. Other configurations, operations, and effects are the same as those of the first embodiment.
また、 上記ポンプダウン機能は、 一般的にポンプダウン運転を自動で行う機 能である。 この自動ポンプダウン運転は、人手によるポンプダウン作業を模擬し、 数分間ならし運転を行った後、 液側閉鎖弁 (41 ) の全閉の代替として電動膨張 弁 (24) を全閉として行う場合がある。 このならし運転により室外ュニット (20) の油が一気に室外ユニッ ト (20) から流出するのを防止するため、 ステップ S T 2 7において、 液側閉鎖弁 (41 ) を全閉としている。 In addition, the above pump down function is generally a function of automatically performing a pump down operation. This automatic pump-down operation simulates a manual pump-down operation. After performing a running-in operation for several minutes, the electric expansion valve (24) is fully closed as an alternative to fully closing the liquid-side stop valve (41). There are cases. In order to prevent the oil of the outdoor unit (20) from flowing out of the outdoor unit (20) at a stretch due to this leveling operation, the liquid side closing valve (41) is fully closed in step ST27.
また、 上記ポンプダウン機能は、 電動膨張弁 (24) が液側閉鎖弁 (41 ) の 代替となっているため液側閉鎖弁 (41 ) 全閉のタイミングをポンプダウン終了 時点としている場合がある。 このため、 ステップ S T 2 7において、 液側閉鎖弁 (41 ) を全閉としている。 一実施形態 3— Also, in the above pump down function, since the electric expansion valve (24) is an alternative to the liquid side closing valve (41), the timing of fully closing the liquid side closing valve (41) may be the end point of the pump down. . Therefore, in step ST27, the liquid-side stop valve (41) is fully closed. Embodiment 3—
次に、 本発明の実施形態 3を図面に基づいて詳細に説明する。 Next, a third embodiment of the present invention will be described in detail with reference to the drawings.
図 6に示すように、 本実施形態は、 実施形態 1が第 2の工程で圧縮機 (21 ) を一旦停止したのに代えて、 圧縮機 (21 ) を継続して駆動したまま循環運転と 回収運転を連続して行うようにしたものである。 As shown in FIG. 6, in the present embodiment, instead of temporarily stopping the compressor (21) in the second step in the first embodiment, the circulation operation is performed while the compressor (21) is continuously driven. The recovery operation is performed continuously.
この空気調和装置 (10) における油回収方法は、 実施形態 1における図 4 のステップ S T 6 , ステップ S T 8及びステップ S T 9が省略されたもので、 そ
の他は、 実施形態 1と同じである。 The oil recovery method in this air conditioner (10) is different from the first embodiment in that steps ST6, ST8, and ST9 in FIG. Other than the above is the same as the first embodiment.
つまり、 先ず、 四路切換弁 (22) を図 1の実線側に切り換え、 正サイクル である冷房サイクルの状態に冷媒回路 (1A) を設定し、 更に、 室内の温度設定 値を最低値に設定する (ステップ S T 4 1 )。 That is, first, the four-way switching valve (22) is switched to the solid line side in Fig. 1, the refrigerant circuit (1A) is set in the cooling cycle state, which is the normal cycle, and the indoor temperature set value is set to the lowest value. (Step ST41).
その後、 第 1の工程を開始し、 冷房サイクルの運転である冷房運転 (循環運 転) を開始してこの冷房運転の運転時間を計数し、 圧縮機 (21 ) が連続して駆 動している場合、 所定時間が経過するまで上述の動作を繰り返し、 冷媒を循環さ せる (ステップ S T 4 2〜ステップ S T 4 5 )。 After that, the first step is started, the cooling operation (circulation operation), which is the operation of the cooling cycle, is started, the operation time of this cooling operation is counted, and the compressor (21) is driven continuously. If so, the above operation is repeated until a predetermined time elapses, and the refrigerant is circulated (step ST42 to step ST45).
その後、 上記所定時間が経過し、 圧縮機 (21 ) が連続して所定時間駆動す ると、 圧縮機 (21 ) の連続して駆動させたまま第 1の工程が終了すると同時に、 液側閉鎖弁 (41 ) を全閉として第 2の工程が開始する (ステップ S T 4 6 )。 Thereafter, when the predetermined time has elapsed and the compressor (21) is continuously driven for a predetermined time, the first step is completed while the compressor (21) is continuously driven, and the liquid side is closed simultaneously. The second step is started by fully closing the valve (41) (step ST46).
つまり、 上記圧縮機 (21 ) が連続して駆動しているので、 液側閉鎖弁 (41 ) の閉鎖によってポンプダウン運転である回収運転が開始される。 つまり、 本実施 形態の空気調和装置 (10) はポンプダウン機能を有しないものの、 上記液側閉 鎖弁 (41 ) を閉じるので、 ポンプダウン運転が開始されたこととなる。 このポ ンプダウン運転が所定時間行われるのを待ち、 所定時間が経過すると、 ガス側閉 鎖弁 (42) を全閉と し、 ポンプダウン運転である冷房運転を停止して第 2のェ 程を終了する (ステップ S T 4 7〜ステップ S T 4 9 )。 この冷房運転によって 冷凍機油が室外ユニッ ト (20) に封じ込められることになる。 That is, since the compressor (21) is continuously driven, the liquid-side shut-off valve (41) is closed to start the pumping-down recovery operation. That is, although the air-conditioning apparatus (10) of the present embodiment does not have a pump-down function, the liquid-side closing valve (41) is closed, so that the pump-down operation is started. Wait for the pump-down operation to be performed for a predetermined time, and after the predetermined time has elapsed, close the gas side shut-off valve (42) completely, stop the cooling operation that is the pump-down operation, and execute the second step. The process ends (step ST47 to step ST49). By this cooling operation, the refrigerating machine oil is confined in the outdoor unit (20).
その後、 第 3の工程に移り、 接続具 (26, 27, 33, 34) から室外ユニッ ト After that, the process moves to the third step, where the outdoor unit is connected via the fittings (26, 27, 33, 34).
(20) 及び室内ユニッ ト (30) を液配管 (51 ) 及びガス配管 (52) より取り外 す。 そして、 新たな室外ユニッ ト (20) 及び室内ユニッ ト (30) を既設の液配 管 (51 ) 及びガス配管 (52) に接続して新設の空気調和装置 (10) の設置が完 了する。 Remove (20) and the indoor unit (30) from the liquid pipe (51) and gas pipe (52). Then, the new outdoor unit (20) and the new indoor unit (30) are connected to the existing liquid piping (51) and gas piping (52), and the installation of the new air conditioner (10) is completed. .
尚、 上記ステップ S T 4 4において、 循環運転である冷房運転中に圧縮機 In step ST44, the compressor is operated during the cooling operation, which is the circulation operation.
(21 ) が停止すると、 ステップ S T 5 0に移り、 冷房運転の時問計数をリセッ トしてステップ S T 4 3に戻り、 冷房運転を継続する。 When (21) stops, the process moves to step ST50, resets the cooling operation time count, returns to step ST43, and continues the cooling operation.
したがって、 本実施形態では、 圧縮機 (21 ) を継続して駆動したまま循環 運転と回収運転を連続して行うようにしたために、 冷媒と油が相溶した状態でこ
の冷媒及び油を室外ユニッ ト (20) 側に回収することができる。 この結果、 油 の回収をより確実にかつ迅速に行うことができる。 その他の構成、 作用及び効果 は、 実施形態 1と同様である。 一実施形態 4一 Therefore, in the present embodiment, the circulation operation and the recovery operation are continuously performed while the compressor (21) is continuously driven, so that the refrigerant and the oil are mixed with each other. Refrigerant and oil can be recovered to the outdoor unit (20). As a result, oil recovery can be performed more reliably and promptly. Other configurations, operations, and effects are the same as those of the first embodiment. One embodiment 41
次に、 本発明の実施形態 4を図面に基づいて詳細に説明する。 Next, a fourth embodiment of the present invention will be described in detail with reference to the drawings.
図 7に示すように、 本実施形態は、 実施形態 3がポンプダウン機能を有しな い空気調和装置 (10) であったのに代わり、 ポンプダウン機能を有する空気調 和装置 (10) とした場合である。 As shown in FIG. 7, in the present embodiment, instead of the air conditioner (10) having no pump-down function in the third embodiment, an air conditioner (10) having a pump-down function is provided. This is the case.
この空気調和装置 (10) における油回収方法は、 実施形態 3における図 6 のステップ S T 4 6の次に図 7のステップ S T 6 7が追加されたもので、 その他 は、 実施形態 3と同じである。 The oil recovery method of this air conditioner (10) is the same as that of the third embodiment except that step ST67 of FIG. 7 is added after step ST46 of FIG. 6 in the third embodiment. is there.
つまり、 先ず、 四路切換弁 (22) を図 1の実線側に切り換え、 正サイクル である冷房サイクルの状態に冷媒回路 (1A) を設定し、 更に、 室内の温度設定 値を最低値に設定する (ステップ S T 6 1 )。 That is, first, the four-way switching valve (22) is switched to the solid line side in Fig. 1, the refrigerant circuit (1A) is set in the cooling cycle state, which is the normal cycle, and the indoor temperature set value is set to the lowest value. (Step ST61).
その後、 第 1の工程を開始し、 冷房サイクルの運転である冷房運転 (循環運 転) を開始してこの冷房運転の運転時間を計数し、 圧縮機 (21 ) が連続して駆 動している場合、 所定時間が経過するまで上述の動作を繰り返し、 冷媒を循環さ せる (ステップ S T 6 2〜ステップ S T 6 5 )。 After that, the first step is started, the cooling operation (circulation operation), which is the operation of the cooling cycle, is started, the operation time of this cooling operation is counted, and the compressor (21) is driven continuously. If so, the above operation is repeated until a predetermined time has elapsed, and the refrigerant is circulated (step ST62 to step ST65).
その後、 上記所定時間が経過し、 圧縮機 (21 ) が連続して所定時間駆動す ると、 圧縮機 (21 ) の連続して駆動させたまま第 1の工程が終了すると同時に、 液側閉鎖弁 (41 ) を全閉として第 2の工程が開始する (ステップ S T 4 6 )。 Thereafter, when the predetermined time has elapsed and the compressor (21) is continuously driven for a predetermined time, the first step is completed while the compressor (21) is continuously driven, and the liquid side is closed simultaneously. The second step is started by fully closing the valve (41) (step ST46).
つまり、 上記圧縮機 (21 ) が連続して駆動している状態において、 ポンプ ダウン運転スィツチである冷媒回収運転スィツチを O Nし、 ポンプダウン運転で ある回収運転が開始される。このポンプダウン運転が所定時間行われるのを待ち、 所定時間が経過すると、 ガス側閉鎖弁 (42) を全閉とし、 ポンプダウン運転で ある冷媒回収運転を停止して第 2の工程を終了する (ステップ S T 6 7〜ステツ プ S T 7 0 )。 この冷媒回収運転によって冷凍機油が室外ユニット (20) に封じ 込められることになる。
その後、 第 3の工程に移り、 接続具 (26, 27, 33, 34) から室外ユニッ トThat is, in a state where the compressor (21) is continuously driven, the refrigerant recovery operation switch which is the pump down operation switch is turned on, and the recovery operation which is the pump down operation is started. Wait for the pump-down operation to be performed for a predetermined time, and when the predetermined time has elapsed, close the gas-side shut-off valve (42) completely, stop the refrigerant recovery operation that is the pump-down operation, and end the second process. (Step ST67 to Step ST70). By this refrigerant recovery operation, the refrigerating machine oil is sealed in the outdoor unit (20). After that, the process moves to the third step, where the outdoor unit is connected through the fittings (26, 27, 33, 34).
(20) 及び室内ユニッ ト (30) を液配管 (51 ) 及びガス配管 (52) より取り外 す。 そして、 新たな室外ユニッ ト (20) 及び室内ユニッ ト (30) を既設の液配 管 (51 ) 及びガス配管 (52) に接続して新設の空気調和装置 (10) の設置が完 了する。 Remove (20) and the indoor unit (30) from the liquid pipe (51) and gas pipe (52). Then, the new outdoor unit (20) and the new indoor unit (30) are connected to the existing liquid piping (51) and gas piping (52), and the installation of the new air conditioner (10) is completed. .
尚、 上記ステップ S T 6 4において、 循環運転である冷房運転中に圧縮機 In step ST64, the compressor is operated during the cooling operation, which is the circulation operation.
(21 ) が停止すると、 ステップ S T 7 1に移り、 冷房運転の時間計数をリセッ トしてステップ S T 6 3に戻り、 冷房運転を継続する。 When (21) stops, the process moves to step ST71, resets the cooling operation time count, returns to step ST63, and continues the cooling operation.
したがって、 本実施形態では、 圧縮機 (21 ) を継続して駆動したまま循環 運転と回収運転を連続して行うようにしたために、 冷媒と油が相溶した状態でこ の冷媒及び油を室外ユニッ ト (20) 側に回収することができる。 この結果、 油 の回収をより確実にかつ迅速に行うことができる。 その他の構成、 作用及び効果 は、 実施形態 3と同様である。 また、 上記ポンプダウン機能については、 実施形 態 2と同様であるので、 ステップ S T 6 6において、 液側閉鎖弁 (41 ) を全閉 としている。 一他の実施形態一 Therefore, in the present embodiment, since the circulation operation and the recovery operation are continuously performed while the compressor (21) is continuously driven, the refrigerant and the oil are mixed in a state where the refrigerant and the oil are mixed. It can be collected at the unit (20) side. As a result, oil recovery can be performed more reliably and promptly. Other configurations, operations, and effects are the same as those of the third embodiment. Further, since the pump-down function is the same as in the second embodiment, the liquid-side stop valve (41) is fully closed in step ST66. Another embodiment one
上記実施形態においては、 循環運転として冷房運転を行うようにしたが、 正 サイクルの運転 (冷房サイクルの運転) としては、 再熱除湿運転、 インバータ制 御を行うインバータ定格冷房運転、 応急運転及び強制冷房運転の何れであっても よい。 In the above embodiment, the cooling operation is performed as the circulating operation. However, as the normal cycle operation (cooling cycle operation), the reheat dehumidification operation, the inverter rated cooling operation for performing the inverter control, the emergency operation, and the forced operation are performed. Any of the cooling operation may be used.
上記再熱除湿運転は、 室内ユニッ ト (30) に室内熱交換器 (31 ) の他に再 熱熱交換器を設けて除湿運転を行う運転である。 The reheat dehumidification operation is an operation in which a reheat heat exchanger is provided in the indoor unit (30) in addition to the indoor heat exchanger (31) to perform the dehumidification operation.
上記応急運転は、 センサ異常や室外ユニッ ト (20) と室内ユニッ ト (30) との間の伝送異常などの理由により通常運転ができなくなった場合に、 サービス マンによる修理までの間で強制的に運転しつづけるため運転であって、 ァクチュ エータが基本的に固定値になる。 この応急運転の場合、 低負荷による発停の頻発 がなくなり連続運転を確実に行うことができる。 If the normal operation cannot be performed due to a sensor error, transmission error between the outdoor unit (20) and the indoor unit (30), etc. This is the operation to keep the operation, and the actuator basically becomes a fixed value. In the case of this emergency operation, frequent start / stop due to low load is eliminated and continuous operation can be reliably performed.
また、 上記応急運転は、 高圧圧力の保護等の保護回路の動作時には一旦停止
するが、 所定時間の経過後に再運転を行う。 したがって、 この循環運転である応 急運転において、 停止することはまれであるが、 この循環運転中に圧縮機 (21 ) が停止した場合は、 圧縮機 (21 ) が再起動した時点を起点として時間計測をや り直す (例えば、 図 4のステップ S T 4及びステップ S T 1 3参照)。 In addition, the above emergency operation is temporarily stopped when a protection circuit such as protection of high pressure is operating. However, the operation will be restarted after the elapse of the specified time. Therefore, it is rare that the compressor (21) stops during the emergency operation which is the circulation operation. However, when the compressor (21) stops during the circulation operation, the time when the compressor (21) is restarted is set as a starting point. Start the time measurement again (for example, see step ST4 and step ST13 in Fig. 4).
上記強制運転は、 ポンプダウン運転や強制的な除霜運転を目的とした運転で あって、 冷媒回路 (1A) が固定され、 ァクチユエータも基本的に固定値になる。 この強制運転の場合、 低負荷による発停の頻発がなくなり連続運転を確実に行う ことができる。 The forcible operation is an operation for the purpose of a pump-down operation or a forcible defrosting operation, in which the refrigerant circuit (1A) is fixed, and the actuator also basically has a fixed value. In the case of this forced operation, frequent start / stop due to low load is eliminated, and continuous operation can be reliably performed.
また、 上記強制運転においては、 高圧圧力の保護等の保護回路の動作時には 一旦停止し、 再運転が行われない。 この循環運転である強制運転が停止すること はまれと考えられるが、 圧縮機 (21 ) が停止した場合は、 圧縮機 (21 ) が再起 動した時点を起点として時間計測をやり直す。 Also, in the above-mentioned forced operation, when the protection circuit such as the protection of the high pressure is operated, the operation is temporarily stopped and the operation is not performed again. It is rare that the forced operation, which is the circulating operation, stops. However, when the compressor (21) stops, the time measurement is performed again starting from the time when the compressor (21) restarts.
また、 本各実施形態では、 回収運転である冷房運転 (冷媒回収運転) を手動 で停止するようにしたが、 自動停止するようにしてもよい。 つまり、 図 1の一点 鎖線で示すように、 圧縮機 (21 ) の吸入側に低圧圧力開閉器 (61 ) を有する場 合、 低圧冷媒圧力が下限値以下になると、 低圧圧力開閉器 (61 ) が作動し、 圧 縮機 (21 ) を強制的に停止し、 回収運転を停止するようにしてもよい。 Further, in each of the embodiments, the cooling operation (refrigerant recovery operation), which is the recovery operation, is manually stopped, but may be automatically stopped. That is, as shown by the dashed line in FIG. 1, when the compressor (21) has a low-pressure switch (61) on the suction side, when the low-pressure refrigerant pressure falls below the lower limit, the low-pressure switch (61) May be operated to forcibly stop the compressor (21) and stop the recovery operation.
また、 上記第 1の工程の循環運転は、 液配管 (51 ) 及びガス配管 (52) の 高低差に対応して該液配管 (51 ) 及びガス配管 (52) の高低差が小さいほど循 環運転の時間を短くするようにしてもよい。 この結果、 水平配管などの場合、 循 環運転である事前運転の時間を短くすることができる。 In addition, in the circulation operation of the first step, the smaller the height difference between the liquid pipe (51) and the gas pipe (52) is, the smaller the difference in height is between the liquid pipe (51) and the gas pipe (52). The driving time may be shortened. As a result, in the case of a horizontal pipe or the like, the time for the pre-operation, which is the circulating operation, can be shortened.
また、 上記第 1の工程の循環運転は、 液配管 (51 ) 及びガス配管 (52) の 長さに対応して該液配管 (51 ) 及びガス配管 (52) の長さが短いほど循環運転 の時間を短くするようにしてもよい。 この結果、 配管長が短い場合、 循環運転で ある事前運転の時間を短くすることができる。 In addition, the circulating operation in the first step is such that the shorter the length of the liquid pipe (51) and the gas pipe (52) is, the shorter the length of the liquid pipe (51) and the gas pipe (52) is. May be shortened. As a result, when the pipe length is short, the time for the preliminary operation, which is the circulation operation, can be shortened.
また、 上記室外ユニッ ト (20) には、 図 1の一点鎖線で示すように、 圧縮 機 (21 ) の吐出側又は冷房サイクルにおける電動膨張弁 (24) の下流側に油分 離器 (60) を設けるようにしてもよい。 この油分離器 (60) を設ける場合、 液 側閉鎖弁 (41 ) の閉鎖時期を回収運転であるポンプダウン運転の開始前に限る
必要がない。 つまり、 上記油分離器 (60) によって油が回収されるので、 ボン プダウン運転の開始時に多量の油が液配管 (51 ) に流出することがない。 この 結果、 液側閉鎖弁 (41 ) の閉鎖時期の自由度が向上する。 The outdoor unit (20) has an oil separator (60) on the discharge side of the compressor (21) or on the downstream side of the electric expansion valve (24) in the cooling cycle, as shown by the dashed line in FIG. May be provided. When this oil separator (60) is installed, the closing time of the liquid side shut-off valve (41) is limited to before the start of the pump-down operation, which is the recovery operation. No need. That is, since the oil is collected by the oil separator (60), a large amount of oil does not flow out to the liquid pipe (51) at the start of the pump-down operation. As a result, the degree of freedom of the closing timing of the liquid side closing valve (41) is improved.
また、 本各実施形態は、 一台の室内ユニッ ト (30) を設けたが、 本発明は、 複数の室内ユニッ ト (30) を有するものであってもよい。 Further, in each of the embodiments, one indoor unit (30) is provided, but the present invention may include a plurality of indoor units (30).
また、 本各実施形態は、 液側閉鎖機構として液側閉鎖弁 (41 ) を設けたが、 電動膨張弁 (24) を全閉に制御することができる場合、 液側閉鎖機構を電動膨 張弁 (24) で構成し、 液側閉鎖弁 (41 ) を省略するようにしてもよい。 Further, in each of the embodiments, the liquid side closing valve (41) is provided as the liquid side closing mechanism. However, when the electric expansion valve (24) can be controlled to be fully closed, the liquid side closing mechanism is electrically expanded. It may be constituted by the valve (24) and the liquid-side shut-off valve (41) may be omitted.
また、 本発明は、 空気調和装置 (10) に限られず、 各種の冷凍装置に適用 することができることは勿論である。 産業上の利用可能性 In addition, the present invention is not limited to the air conditioner (10), and it is needless to say that the present invention can be applied to various refrigeration devices. Industrial applicability
以上のように、 本発明に係る冷凍装置の油回収方法は、 熱源ユニッ トと利用 ユニッ トとを接続する配管の油を回収する場合に有用であり、 特に、 H F C系冷 媒又は H C系冷媒を使用した新たな冷凍装置に更新する場合の油回収に適してい る。
As described above, the oil recovery method for a refrigerating apparatus according to the present invention is useful for recovering oil from a pipe connecting a heat source unit and a utilization unit, and particularly, an HFC-based refrigerant or an HC-based refrigerant. Suitable for oil recovery when upgrading to a new refrigeration unit using
Claims
1 . 熱源ユニッ ト (20) と利用ユニッ ト (30) とが配管 (51 , 52) によって接 続され、蒸気圧縮式冷凍サイクルを行う冷媒回路(1A) を備え、該冷媒回路 (1A) の油を熱源ユニッ ト (20) 側に回収する冷凍装置の油回収方法であって、 1. The heat source unit (20) and the utilization unit (30) are connected by pipes (51, 52) and have a refrigerant circuit (1A) for performing a vapor compression refrigeration cycle. An oil recovery method for a refrigeration system that recovers oil to the heat source unit (20) side,
上記熱源ユニッ ト (20) で冷媒が凝縮する冷媒回路 (1A) の正サイクルの 運転状態において、 上記冷媒回路 (1A) の圧縮機 (21 ) を連続して駆動させ、 冷媒回路 (1A) 内で冷媒を循環させる循環運転を所定時間が経過するまで行う 第 1の工程と、 In a normal cycle operation state of the refrigerant circuit (1A) in which the refrigerant condenses in the heat source unit (20), the compressor (21) of the refrigerant circuit (1A) is continuously driven, and the refrigerant circuit (1A) A first step of performing a circulation operation to circulate the refrigerant until a predetermined time elapses,
該第 1の工程に続き、 上記圧縮機 (21 ) を継続して駆動して上記冷媒回路 ( 1A) の冷媒を油と共に熱源ユニッ ト (20) 側に回収する回収運転を行う第 2 の工程とを備えている Subsequent to the first step, a second step of performing a recovery operation of continuously driving the compressor (21) to recover the refrigerant of the refrigerant circuit (1A) together with oil to the heat source unit (20) side. Has
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
2 . 熱源ユニッ ト (20) と利用ユニッ ト (30) とが配管 (51, 52) によって接 続され、蒸気圧縮式冷凍サイクルを行う冷媒回路(1A) を備え、該冷媒回路 (1A) の油を熱源ユニッ ト (20) 側に回収する冷凍装置の油回収方法であって、 2. The heat source unit (20) and the utilization unit (30) are connected by pipes (51, 52) and have a refrigerant circuit (1A) for performing a vapor compression refrigeration cycle. An oil recovery method for a refrigeration system that recovers oil to the heat source unit (20) side,
上記熱源ユニッ ト (20) で冷媒が凝縮する冷媒回路 (1A) の正サイクルの 運転状態において、 上記冷媒回路 (1A) の圧縮機 (21 ) を連続して駆動させ、 冷媒回路 (1A) 内で冷媒を循環させる循環運転を所定時間が経過するまで行う 第 1の工程と、 In a normal cycle operation state of the refrigerant circuit (1A) in which the refrigerant condenses in the heat source unit (20), the compressor (21) of the refrigerant circuit (1A) is continuously driven, and the refrigerant circuit (1A) A first step of performing a circulation operation to circulate the refrigerant until a predetermined time elapses,
該第 1の工程が終了すると、 上記圧縮機 (21 ) を一旦停止した後、 該圧縮 機 (21 ) を駆動して上記冷媒回路 (1A) の冷媒を油と共に熱源ユニッ ト (20) 側に回収する回収運転を行う第 2の工程とを備えている When the first step is completed, the compressor (21) is temporarily stopped, and then the compressor (21) is driven to transfer the refrigerant in the refrigerant circuit (1A) together with oil to the heat source unit (20) side. And a second step of performing a recovery operation for recovery.
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
3 . 請求項 1又は 2において、 3. In Claim 1 or 2,
上記熱源ュニッ ト (20) が圧縮機 (21 ) と熱源側熱交換器 (23) と膨張機 構 (24) とを備え、 該熱源ユニッ ト (20) は、 液側閉鎖弁 (41 ) を介して液側
の配管 (51 ) に接続されると共に、 ガス側閉鎖弁 (42) を介してガス側の配管 (52) に接続される一方、 The heat source unit (20) includes a compressor (21), a heat source side heat exchanger (23), and an expansion mechanism (24), and the heat source unit (20) has a liquid side closing valve (41). Through the liquid side While being connected to the gas side pipe (52) via the gas side shutoff valve (42),
上記第 2の工程は、 液側閉鎖弁 (41 ) を閉鎖した状態で回収運転を開始し、 該回収運転の終了後にガス側閉鎖弁 (42) を閉鎖する In the second step, the recovery operation is started with the liquid-side stop valve (41) closed, and the gas-side stop valve (42) is closed after the completion of the recovery operation.
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
4 . 請求項 1又は 2において、 4. In Claim 1 or 2,
上記利用ユニッ ト (30) は、 利用側熱交換器 (31 ) と風量の可変な利用側 ファン (32) とを備える一方、 The usage unit (30) includes a usage-side heat exchanger (31) and a usage-side fan (32) having a variable air volume,
上記第 1の工程は、 上記利用側ファン (32) を風量が大きい高風量で駆動 させて循環運転を行う In the first step, the utilization side fan (32) is driven at a high air flow with a large air flow to perform a circulation operation.
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
5 . 請求項 1又は 2において、 5. In Claim 1 or 2,
上記利用ユニッ ト (30) は、 利用側熱交換器 (31 ) と風量の可変な利用側 ファン (32) とを備える一方、 The usage unit (30) includes a usage-side heat exchanger (31) and a usage-side fan (32) having a variable air volume,
上記第 1の工程は、 上記利用側ファン (32) を風量が小さい低風量で駆動 させて循環運転を行う In the first step, the utilization side fan (32) is driven at a low air flow with a small air flow to perform a circulation operation.
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
6 . 請求項 1又は 2において、 6. In Claim 1 or 2,
上記利用ユニッ ト (30) は、 利用側熱交換器 (31 ) と風量の可変な利用側 ファン (32) とを備える一方、 The usage unit (30) includes a usage-side heat exchanger (31) and a usage-side fan (32) having a variable air volume,
上記第 1の工程は、 循環運転の前半で上記利用側ファン (32) を風量が大 きい高風量で駆動させ、 循環運転の後半で上記利用側ファン (32) を風量が小 さい低風量で駆動させる In the first step, the use side fan (32) is driven at a high air flow with a large air flow in the first half of the circulation operation, and the use side fan (32) is driven at a low air flow with a small air flow in the second half of the circulation operation. Drive
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
7 . 請求項 1又は 2において、
上記第 1の工程は、 上記配管 (51, 52) の高低差に対応して配管 (51, 52) の高低差が小さいほど循環運転の時間を短くする 7. In Claim 1 or 2, In the first step, the circulation operation time is shortened as the height difference of the pipes (51, 52) is smaller in accordance with the height difference of the pipes (51, 52).
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
8 . 請求項 1又は 2において、 8. In Claim 1 or 2,
上記第 1の工程は、 上記配管 (51, 52) の長さに対応して配管 (51, 52) の長さが短いほど循環運転の時間を短くする In the first step, the circulation operation time is shortened as the length of the pipe (51, 52) is shorter in accordance with the length of the pipe (51, 52).
ことを特徴とする冷凍装置の油回収方法。 An oil recovery method for a refrigeration apparatus, comprising:
9 . 請求項 1又は 2において、 9. In Claim 1 or 2,
上記熱源ユニッ ト (20) は、 圧縮機 (21 ) と熱源側熱交換器 (23) と膨張 機構 (24) とを備え、 The heat source unit (20) includes a compressor (21), a heat source side heat exchanger (23), and an expansion mechanism (24).
上記熱源ユニッ ト (20) には、 圧縮機 (21 ) の吐出側又は正サイクルにお ける膨張機構 (24) の下流側に油分離器 (60) が設けられている The heat source unit (20) is provided with an oil separator (60) on the discharge side of the compressor (21) or on the downstream side of the expansion mechanism (24) in the normal cycle.
ことを特徴とする冷凍装置の油回収方法。
An oil recovery method for a refrigeration apparatus, comprising:
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JPH08200895A (en) * | 1995-01-31 | 1996-08-06 | Daikin Ind Ltd | Refrigerant recovery method of freezer |
JPH08226731A (en) * | 1995-02-22 | 1996-09-03 | Hitachi Ltd | Air conditioning equipment |
JPH09138017A (en) * | 1995-11-16 | 1997-05-27 | Sanyo Electric Co Ltd | Multi-chamber split type cooling and heating apparatus |
EP1018628A1 (en) * | 1997-09-12 | 2000-07-12 | Daikin Industries, Limited | Refrigerant recovering apparatus and refrigerant recovering method |
JP2000161749A (en) * | 1998-11-24 | 2000-06-16 | Matsushita Refrig Co Ltd | Controller for air conditioner |
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