CN113418328A - Control method for refrigerating and freezing unit and refrigerating and freezing unit - Google Patents
Control method for refrigerating and freezing unit and refrigerating and freezing unit Download PDFInfo
- Publication number
- CN113418328A CN113418328A CN202110592704.2A CN202110592704A CN113418328A CN 113418328 A CN113418328 A CN 113418328A CN 202110592704 A CN202110592704 A CN 202110592704A CN 113418328 A CN113418328 A CN 113418328A
- Authority
- CN
- China
- Prior art keywords
- shutdown
- compressor
- indoor
- unit
- control method
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 82
- 238000007710 freezing Methods 0.000 title claims abstract description 79
- 230000008014 freezing Effects 0.000 title claims abstract description 78
- 238000005057 refrigeration Methods 0.000 claims abstract description 56
- 239000003507 refrigerant Substances 0.000 description 37
- 239000007788 liquid Substances 0.000 description 33
- 239000003921 oil Substances 0.000 description 10
- 238000010257 thawing Methods 0.000 description 9
- 238000004891 communication Methods 0.000 description 8
- 230000001276 controlling effect Effects 0.000 description 8
- 238000001704 evaporation Methods 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 238000012271 agricultural production Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000002274 desiccant Substances 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Images
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
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention relates to a control method for a refrigerating and freezing unit. The refrigeration and refrigeration unit comprises an outdoor unit and an indoor unit which can be interconnected, the outdoor unit is provided with an outdoor dry contact terminal, the outdoor dry contact terminal forms a short circuit or is connected with an indoor dry contact terminal of the indoor unit through a signal wire, and after the refrigeration and refrigeration unit is powered on, the control method comprises the following steps: detecting the indoor temperature; judging whether the indoor temperature reaches a preset starting temperature value or not; when the indoor temperature reaches a preset starting temperature value, closing an indoor electromagnetic valve of the refrigerating and freezing unit; judging whether the outdoor unit is powered on for the first time; when the outdoor unit is not powered on for the first time, judging whether the previous shutdown memory of the compressor is the signal shutdown memory or the pressure shutdown memory; when the signal is the signal shutdown memory, controlling the compressor to start in a first starting mode; and when it is a pressure shutdown memory, controlling the compressor to start in a second start-up mode. The control method can ensure that the refrigerating and freezing unit is started accurately and timely.
Description
Technical Field
The invention relates to the technical field of refrigeration, in particular to a control method for a refrigeration and freezing unit and the refrigeration and freezing unit.
Background
In the modern industrial and agricultural production process, the refrigerating and freezing unit can provide effective temperature control, so that the continuous improvement of the production efficiency and the product quality is promoted, and therefore, the refrigerating and freezing unit is widely applied to various fields of food processing, mechanical manufacturing, medicine production, grain storage and the like. Refrigeration and freezing units, including but not limited to water-cooled units and air-cooled units, may be used to cool refrigerators directly with a refrigerant (also referred to as "refrigerant") to provide suitable refrigeration and/or freezing temperatures. Some refrigeration and freezing units employ a vapor compression refrigeration cycle, such as using a screw compressor or scroll compressor. The refrigeration and freezing unit further includes at least a condenser, an evaporator, and an expansion device. The refrigerating and freezing unit can be divided into two parts, an outdoor unit (which is usually placed in an outdoor environment) and an indoor unit (which is usually placed in an indoor environment to be temperature-regulated) which are interconnected with each other. The compressor and the condenser are disposed in the outdoor unit, and the evaporator and the expansion device are disposed in the indoor unit. In the refrigeration cycle, the compressor sucks a low-temperature and low-pressure gaseous refrigerant through the suction port and compresses the refrigerant into a high-temperature and high-pressure gaseous refrigerant. The high-temperature and high-pressure gaseous refrigerant is discharged from a discharge port of the compressor and flows into the condenser along a pipe. In the condenser, a high-temperature and high-pressure gaseous refrigerant is condensed into a medium-temperature and high-pressure liquid refrigerant by means of an air cooling or water cooling method. The medium-temperature high-pressure liquid refrigerant flows from the condenser to the expansion device along the pipeline, and is throttled in the expansion device into low-temperature low-pressure liquid refrigerant. The low-temperature low-pressure liquid refrigerant flows along the pipeline to the evaporator. In the evaporator, the liquid refrigerant is evaporated into a low-temperature and low-pressure gaseous refrigerant by absorbing heat of the indoor air, and the indoor air is cooled to a predetermined target refrigerating temperature or a target freezing temperature. The low-temperature and low-pressure gaseous refrigerant is then sucked and compressed again by the compressor, thereby starting a new refrigeration cycle.
The outdoor unit of the refrigeration and freezing unit may be provided with outdoor dry contact terminals including positive and negative outdoor dry contact terminals. Some indoor units are equipped with corresponding indoor dry contact terminals, including positive and negative indoor dry contact terminals, and the indoor dry contact terminals are generally combined with indoor solenoid valves provided in the indoor units, so that the closing and opening of the indoor solenoid valves controls the closing and opening between the indoor dry contact terminals. When the indoor unit has an indoor dry contact terminal, communication between the indoor unit and the outdoor unit can be performed through a signal line connecting the indoor dry contact terminal and the outdoor dry contact terminal, a generated communication signal can be called a "dry contact signal", and the dry contact signal can be interrupted under certain conditions, such as shutdown of the indoor unit or when the indoor temperature reaches a set temperature. When the outdoor unit is provided with the outdoor dry contact terminal and the indoor unit is not provided with the indoor dry contact terminal, no communication connection exists between the outdoor unit and the indoor unit, the outdoor dry contact terminal can form a short circuit, and a dry contact signal is generated under the condition. The dry contact signal is only switched off when the outdoor unit is powered off, and otherwise remains switched on.
When the outdoor unit or the indoor unit has no dry contact terminal, a signal line can be saved without considering the matching of the indoor unit and the outdoor unit, and the outdoor unit can be matched with various indoor units (with/without terminals). However, the start and stop control of the refrigerating and freezing unit is entirely dependent on the system pressure and is single in control. Furthermore, the system control is greatly influenced by the setting of the start-stop pressure value, the working condition range of the running environment of the refrigerating and freezing unit is limited, and if the pressure value is not accurately set, the low-pressure early warning risk is caused; the frequency of start and stop is more and the energy saving performance is poor. User/after-market installation misoperation (including setting the evaporation temperature out of range and the like) has the probability of causing unit false start and false stop.
Accordingly, there is a need in the art for a new solution to the above problems.
Disclosure of Invention
In order to solve the above-mentioned problems in the prior art, that is, in order to solve the technical problem that the refrigerator-freezer unit can be accurately and timely started under the condition that the communication connection and the non-communication connection exist between the outdoor unit and the indoor unit of the refrigerator-freezer unit, the invention provides a control method for the refrigerator-freezer unit, wherein the refrigerator-freezer unit comprises the outdoor unit and the indoor unit which can be interconnected, the outdoor unit is provided with an outdoor dry contact terminal, and the outdoor dry contact terminal forms a short circuit or is connected with an indoor dry contact terminal of the indoor unit through a signal wire, and when the refrigerator-freezer unit is electrified, the control method comprises the following steps:
detecting the indoor temperature;
judging whether the indoor temperature reaches a preset starting temperature value or not;
when the indoor temperature reaches the preset starting temperature value, closing an indoor electromagnetic valve of the refrigerating and freezing unit;
judging whether the outdoor unit is powered on for the first time;
when the outdoor unit is not powered on for the first time, judging whether the previous shutdown memory of the compressor is signal shutdown memory or pressure shutdown memory;
when the previous shutdown memory is the signal shutdown memory, controlling the compressor to start in a first starting mode; and is
And when the previous shutdown memory is the pressure shutdown memory, controlling the compressor to start in a second starting mode.
As can be understood by those skilled in the art, in the technical solution of the control method for the refrigerating and freezing unit of the present invention, the outdoor unit group of the refrigerating and freezing unit is provided with the outdoor dry contact terminal, and the outdoor dry contact terminal itself forms a short circuit or is connected with the indoor dry contact terminal of the indoor unit through a signal line. When the outdoor dry contact terminal and the indoor dry contact terminal are connected through a signal line under the condition that the refrigerating and freezing unit is electrified, a dry contact signal can be generated in the signal line when the indoor dry contact is triggered to be closed. Alternatively, the dry contact signal may be generated when the outdoor dry contact terminal itself is short-circuited (i.e., a short circuit is formed between the outdoor positive and negative dry contact terminals) when the refrigeration and freezing unit is energized. Furthermore, when the outdoor dry contact terminal is connected with the indoor dry contact terminal through a signal line, the start and stop of the refrigerating and freezing unit can be controlled through the dry contact signal, and the start and stop control mode of the dry contact signal can accurately control the start and stop of the refrigerating and freezing unit. When the outdoor dry contact terminal forms a short circuit, the dry contact signal start-stop control mode is not applicable any more, and an alternative start-stop control mode is required. In order to satisfy both of the above two cases, the control method of the present invention adopts the following manner. Firstly, detecting the indoor temperature and judging whether the indoor temperature reaches a preset starting temperature value or not. The preset starting temperature value is set according to different working conditions and use environments of the refrigerating and freezing unit, so that the preset starting temperature value is variable, and the preset starting temperature value is matched with the actual working conditions and the environments. And when the indoor temperature reaches the preset starting temperature value, closing an indoor electromagnetic valve of the refrigerating and freezing unit. When the outdoor dry contact terminal is connected with the indoor dry contact terminal through the signal line, the indoor solenoid valve is closed to cause the indoor dry contact terminal to be closed, so that a dry contact signal is generated in the signal line, namely the dry contact signal is connected. And after the indoor electromagnetic valve is closed, judging whether the outdoor unit is powered on for the first time. And if the outdoor unit is not powered on for the first time, judging whether the previous shutdown memory of the compressor is the signal shutdown memory or the pressure shutdown memory. When the previous shutdown memory is the signal shutdown memory, controlling the compressor to start in a first starting mode; when the previous shutdown memory is the pressure shutdown memory, the compressor is controlled to start in a second starting mode. The method for controlling the starting of the compressor according to the last shutdown memory fully considers the two conditions of the signal line and the signal line absence between the outdoor unit and the indoor unit so as to ensure that the refrigerating and freezing unit can be accurately and timely started under the two conditions.
In a preferred embodiment of the control method for a refrigerator-freezer unit, in the first start-up mode, the control method includes:
determining a current live shutdown duration of the compressor;
and starting the compressor when the current electrified shutdown time reaches a preset shutdown time. The last shutdown memory is the signal shutdown memory, which indicates that the dry contact signal connection exists between the outdoor unit and the indoor unit, so that the starting of the refrigerating and freezing unit can be controlled through the dry contact signal. In this case, closing of the indoor solenoid valve of the refrigeration and freezing unit causes the indoor dry contact terminal to be closed, and the dry contact signal is turned on. Therefore, in the first start-up mode, it is only necessary to determine whether the current electrified shutdown period of the compressor reaches the predetermined shutdown period. The compressor can be started immediately if the current live shutdown period of the compressor reaches the predetermined shutdown period. And if the current electrified shutdown time of the compressor does not reach the preset shutdown time, the compressor cannot be started so as to maintain the start-stop service life of the compressor.
In a preferred embodiment of the control method for a refrigerator-freezer unit, in the second start-up mode, the control method includes:
determining the current electrified shutdown time length of the compressor and detecting the current suction pressure of the compressor;
and starting the compressor when the current electrified shutdown time reaches a preset shutdown time and the current suction pressure reaches a preset starting pressure value. If the last shutdown memory is a pressure shutdown memory, it indicates that no dry contact signal connection exists between the outdoor unit and the indoor unit (i.e., the outdoor dry contact terminal is short-circuited), or the pressure of the refrigeration and freezing unit is abnormal, and the refrigeration and freezing unit cannot be started through the dry contact signal under the two conditions. Thus, the start-up of the compressor adopts the second start-up mode. In the second starting mode, whether the current electrified shutdown time of the compressor reaches the preset shutdown time or not is judged, and whether the current suction pressure of the compressor reaches the preset starting pressure value or not is also judged. If either of the two conditions is not satisfied, the compressor cannot be started, thereby achieving the purpose of protecting the compressor.
In a preferred embodiment of the control method for the refrigeration and freezing unit, when the outdoor unit is powered on for the first time, the compressor is controlled to start in the first starting mode. Under the condition that the outdoor unit is electrified for the first time, the previous shutdown memory does not exist, so that whether the current electrified shutdown time of the compressor reaches the preset shutdown time or not is only judged. The compressor can be started immediately if the current live shutdown period of the compressor reaches the predetermined shutdown period. And if the current electrified shutdown time of the compressor does not reach the preset shutdown time, the compressor cannot be started so as to maintain the start-stop service life of the compressor.
In a preferred embodiment of the above-described control method for a refrigeration-freezer unit,
short circuit of the outdoor dry contact terminal generates a dry contact signal; or
The outdoor dry contact terminal and the indoor dry contact terminal of the indoor unit are connected through the signal line, and the indoor dry contact terminal and the indoor solenoid valve are combined together such that the dry contact signal is generated in the signal line when the indoor solenoid valve is closed. The indoor dry contact terminal is combined with the indoor electromagnetic valve, so that the action of the indoor electromagnetic valve can trigger the action of the indoor dry contact terminal, namely when the indoor electromagnetic valve is closed, the indoor dry contact terminal is also closed, and therefore a dry contact signal is generated in the signal wire; when the indoor solenoid valve is opened, the indoor dry contact terminal is also opened, and thus the dry contact signal in the signal line is also interrupted. On the contrary, when the unit is energized, the dry contact signal generated by the short circuit of the outdoor dry contact terminal is always kept on, and the interruption does not occur. Therefore, whether the dry contact signal connection exists between the outdoor unit and the indoor unit can be judged based on whether the dry contact signal is interrupted.
In a preferred embodiment of the control method for a refrigerator-freezer unit, the control method further includes:
judging whether the indoor temperature reaches a preset shutdown temperature value or not;
when the indoor temperature reaches the preset shutdown temperature value, disconnecting the indoor electromagnetic valve;
judging whether the dry contact signal is disconnected or not;
when the dry contact signal is off, the compressor is shut down and the signal shutdown memory is generated. And if the dry contact signal is disconnected, the outdoor unit is connected with the indoor unit through a signal line, so that the outdoor unit is controlled to stop through the disconnection of the dry contact signal.
In a preferred embodiment of the above control method for a refrigerator-freezer unit, when the dry contact signal is not turned off, the control method includes:
judging whether the precision shutdown mode is shielded or not;
controlling the compressor to enter a lowest pressure shutdown mode when the precision shutdown mode is masked; and is
Controlling the compressor to enter a precision shutdown mode when the precision shutdown mode is not masked. When the indoor electromagnetic valve is disconnected, the dry contact signal is not disconnected, which indicates that no signal line is connected between the outdoor unit and the indoor unit. In this case, consideration is again given to the case where the accuracy control requirement is masked, in order to ensure that the refrigerator-freezer unit can be stopped accurately and promptly in these cases.
In a preferred embodiment of the control method for a refrigeration and freezing unit, in the minimum pressure stop mode, the control method includes:
detecting a current suction pressure of the compressor;
comparing the current suction pressure to a predetermined minimum shutdown pressure value;
when the current suction pressure is less than or equal to the predetermined minimum shutdown pressure value, the compressor is shutdown and the pressure shutdown memory is generated. The technical scheme considers the condition that no signal wire exists between the outdoor unit and the indoor unit and the precision control is shielded, so that the refrigeration and freezing unit can be accurately stopped in time under the condition.
In a preferred embodiment of the control method for a refrigerator-freezer unit described above, in the precision stop mode, the control method includes:
detecting a current suction pressure of the compressor;
comparing the current suction pressure with a preset precision shutdown pressure value;
when the current suction pressure is less than or equal to the precision shutdown pressure value, the compressor is shut down and the pressure shutdown memory is generated. The technical scheme considers the condition that no signal wire exists between the outdoor unit and the indoor unit and the precision control is not shielded, so that the refrigeration and freezing unit can be accurately and timely stopped under the condition.
The invention also relates to a refrigerator-freezer unit comprising a compressor and the compressor is controlled using a control method according to any of the above. By the control method for the refrigerating and freezing unit, the refrigerating and freezing unit can be ensured to accurately and timely start and/or stop under the two conditions of signal lines and no signal lines between the outdoor unit and the indoor unit.
Drawings
Preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:
FIG. 1 is a system schematic of an embodiment of a refrigeration and freezing assembly of the present invention;
fig. 2 is a flow chart of a control method for a refrigeration and freezing assembly according to the present invention;
fig. 3 is a start-up flow chart of an embodiment of the control method for a refrigeration and freezing unit according to the present invention;
fig. 4 is a stop flow diagram of an embodiment of the control method for a refrigeration and freezing assembly of the present invention.
List of reference numerals:
1. a refrigeration and freezing unit; 11. an outdoor unit; 111. a compressor; 111a, compressor heating belt; 112a, an exhaust pipe; 112b, liquid pipe; 112c, a gas pipe; 112d, an air suction pipe; 113. a high voltage protection switch; 114. an oil separator; 115. an oil return capillary tube; 116. a one-way valve; 117. a high pressure sensor; 118. an outdoor heat exchanger; 119. a high pressure reservoir; 119a, a high-pressure reservoir heating belt; 120. drying the filter; 121. a liquid viewing mirror; 122. a liquid pipe stop valve; 123. an air pipe stop valve; 124. a gas-liquid separator; 125. a low pressure sensor; 126. a hot defrosting bypass pipeline; 127. a hot defrosting stop valve; 128. an outdoor balanced bypass line; 129. an outdoor bypass electromagnetic valve; 21. an indoor unit; 211. an indoor heat exchanger; 212. an expansion valve; 213. an indoor solenoid valve.
Detailed Description
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and are not intended to limit the scope of the present invention.
In order to solve the technical problem that the refrigerating and freezing unit can be accurately and timely started under the conditions that the outdoor unit and the indoor unit of the refrigerating and freezing unit are in communication connection and are not in communication connection, the invention provides a control method for the refrigerating and freezing unit, wherein the refrigerating and freezing unit comprises the outdoor unit and the indoor unit which can be interconnected, the outdoor unit is provided with an outdoor dry contact terminal, the outdoor dry contact terminal forms a short circuit or is connected with an indoor dry contact terminal of the indoor unit through a signal line, and when the refrigerating and freezing unit is electrified, the control method comprises the following steps:
detecting an indoor temperature (step S1);
judging whether the indoor temperature reaches a preset starting temperature value or not (step S2);
when the indoor temperature reaches the preset starting temperature value, closing an indoor electromagnetic valve of the refrigerating and freezing unit (step S3);
judging whether the outdoor unit is powered on for the first time or not (step S4);
when the outdoor unit is not powered on for the first time, judging whether the previous shutdown memory of the compressor is a signal shutdown memory or a pressure shutdown memory (step S5);
controlling the compressor to start in a first start mode when the previous shutdown memory is the signal shutdown memory (step S6); and is
And controlling the compressor to start in a second starting mode when the previous shutdown memory is the pressure shutdown memory (step S7).
The process steps referred to herein are not necessarily required to be in the order of their presentation unless specifically stated, e.g., some process steps may be performed concurrently.
Figure 1 is a system schematic of an embodiment of a refrigeration and freezing assembly of the present invention. As shown in fig. 1, in one or more embodiments, the refrigeration-freezer unit 1 includes an outdoor unit 11 (which is typically disposed in an outdoor environment) and one indoor unit 21 (which is typically disposed indoors or in a room). Alternatively, the refrigerating-freezing unit 1 may be provided with a plurality of parallel-connected indoor units, for example two, three, four or another suitable number of indoor units. Fig. 1 shows only one indoor unit 21. In the case where a plurality of indoor units are arranged, the arrangement of the plurality of indoor units may be the same or different depending on actual needs. The outdoor unit 11 has a control panel (not shown) or a computer board. The control panel is provided with an outdoor dry contact terminal (not shown in the figure), which comprises a positive outdoor dry contact terminal and a negative outdoor dry contact terminal. In one or more embodiments, the indoor unit 21 is provided with an indoor dry contact terminal, and the indoor dry contact terminal and the outdoor dry contact terminal are connected by a signal line, thereby allowing communication between the outdoor unit and the indoor unit. Alternatively, the indoor unit 21 is not provided with an indoor dry contact terminal. In this case, the outdoor dry contact terminal itself forms a short.
As shown in fig. 1, in one or more embodiments, the outdoor unit 11 mainly includes a compressor 111, an outdoor heat exchanger 118, a high-pressure accumulator 119, and a gas-liquid separator 124; the indoor unit 21 mainly includes an indoor heat exchanger 211, an expansion valve 212, and an indoor solenoid valve 213. In the case where the indoor unit 21 is provided with an indoor dry contact terminal, the indoor dry contact terminal is integrated with the indoor solenoid valve 213, and the closing of the indoor solenoid valve 213 may cause the indoor dry contact terminal to be closed; conversely, when the indoor solenoid valve 213 is opened, the indoor dry contact terminal is also opened. The compressor 111 has a discharge port and a suction port (not shown). The discharge port of the compressor 111 is connected to the input end of the outdoor heat exchanger 118 through a discharge pipe 112 a; the output end of the outdoor heat exchanger 118 is connected to the high-pressure reservoir 119, the expansion valve 212 of the indoor unit 21, and the indoor heat exchanger 211 in this order through the liquid pipe 112 b; the indoor heat exchanger 211 is connected to an inlet of the gas-liquid separator 124 through a gas pipe 112c, and an outlet of the gas-liquid separator 124 is connected to an inlet of the compressor 111 through a suction pipe 112d, thereby being interconnected to form a refrigeration cycle allowing a refrigerant to flow therein.
As shown in FIG. 1, in one or more embodiments, the compressor 111 is an inverter compressor. Alternatively, the compressor 111 may include two or more compressors in parallel. These compressors may be all inverter compressors or may include some inverter compressors. In one or more embodiments, a high pressure protection switch 113 is disposed on the discharge line 112a near the discharge of the compressor 111 to provide shutdown protection when the discharge pressure of the compressor 111 is too high. In one or more embodiments, an oil separator 114 is disposed on the exhaust pipe 112a, wherein a gas input end of the oil separator 114 is connected to an exhaust port of the compressor 111; the gas output of the oil separator 114 is connected to the input of the outdoor heat exchanger 118 through the gas discharge pipe 112 a; the oil return discharge end of the oil separator 114 is connected to an oil return capillary tube 115 and is connected to the suction port of the compressor 111 through a pipe so as to return the lubricating oil to the compressor 111 in time. In one or more embodiments, a compressor heating zone 111a is provided at the bottom of the compressor 111 to preheat the compressor when needed. In one or more embodiments, a check valve 116 for preventing the refrigerant from flowing backwards and a high pressure sensor 117 for detecting the discharge pressure of the compressor 111 are further disposed on the discharge pipe 112a, and both the check valve 116 and the pressure sensor 117 are located downstream of the gas output end of the oil separator 114.
As shown in fig. 1, in one or more embodiments, the outdoor heat exchanger 118 may be, but is not limited to, a finned coil heat exchanger or a plate heat exchanger, and is equipped with an outdoor heat exchanger fan (not shown). The high pressure accumulator 119 may receive the liquid refrigerant condensed by the outdoor heat exchanger 118 to adjust and ensure a refrigerant circulation amount in the refrigeration system. In one or more embodiments, a high pressure accumulator heating belt 119a is provided on the high pressure accumulator 119 to preheat the liquid refrigerant, ensuring accurate supply of the refrigerant. A dry filter 120, a sight glass 121, and a liquid pipe shutoff valve 122 are also connected in series in this order to the liquid pipe 112b downstream of the high-pressure accumulator 119. The desiccant filter 120 may dry moisture in the liquid refrigerant, the liquid sight glass 121 may be used to observe a flow condition of the liquid refrigerant and detect a water content in the refrigerant, and the liquid tube stop valve 122 may help to temporarily store the refrigerant in the refrigeration cycle loop outside the room, so as to perform disassembly, maintenance and service on the refrigeration and freezing unit 1. In one or more embodiments, an indoor solenoid valve 213 is further disposed at a position of the liquid pipe 112b upstream of the expansion valve 212 to control the liquid refrigerant to flow into the indoor unit 21.
As shown in fig. 1, in one or more embodiments, the expansion valve 212 is a thermal expansion valve. Alternatively, the expansion valve 212 may be an electronic expansion valve, or other suitable expansion valve. The indoor heat exchanger 211 includes, but is not limited to, a fin-and-coil heat exchanger and a plate heat exchanger, and is provided with an indoor heat exchanger fan (not shown in the drawings). The gas pipe 112c is further provided with a gas pipe shutoff valve 123 to assist the refrigerant in the refrigeration cycle circuit to be temporarily stored outside the room in cooperation with the liquid pipe shutoff valve 122.
As shown in fig. 1, in one or more embodiments, a low pressure sensor 125 is further disposed on the suction pipe 112d to detect a suction pressure of the compressor 111. In one or more embodiments, a hot defrosting bypass line 126 is connected in parallel between the gas output end close to the oil-gas separator 114 and the output end of the indoor heat exchanger 211, and a hot defrosting stop valve 127 is arranged on the hot defrosting bypass line 126, so that when the indoor heat exchanger 211 needs defrosting, the hot defrosting stop valve 127 is opened, and high-temperature steam output from the exhaust port of the compressor 111 is allowed to be directly conveyed to the indoor heat exchanger 211 through the hot defrosting bypass line 126 for defrosting treatment. In one or more embodiments, an outdoor balance bypass line 128 is connected in parallel between the exhaust pipe 112a and the suction pipe 112d, and an outdoor bypass solenoid valve 129 is disposed on the outdoor balance bypass line 128.
When the refrigerating and freezing unit 1 receives a cooling instruction, the compressor 111 starts to operate, and the refrigerant (for example, R410a) is compressed by the compressor 111 and then enters the outdoor heat exchanger 113 (which serves as a condenser) through the exhaust pipe 112a in the form of a high-temperature and high-pressure gas. In the outdoor heat exchanger 113, the high-temperature and high-pressure gas refrigerant is condensed into a high-temperature and high-pressure liquid refrigerant by transferring heat to an air flow caused by the outdoor heat exchanger fan. The high-temperature and high-pressure liquid refrigerant flows through the high-pressure accumulator 119, the dry filter 120, the liquid scope 121, and the liquid tube shutoff valve 122 in this order, and flows to the expansion valve 212 of the indoor unit 21. The expansion valve 212 throttles the high-temperature and high-pressure liquid refrigerant to a low-temperature and low-pressure liquid refrigerant, and distributes the refrigerant to the indoor heat exchanger 211. The low-temperature and low-pressure liquid refrigerant is evaporated into a low-temperature and low-pressure gas refrigerant by absorbing heat of the indoor air, and the indoor air is cooled. The low-temperature and low-pressure gaseous refrigerant exits the indoor heat exchanger 211, passes through the corresponding gas pipe 112c and the gas pipe shutoff valve 123, and then enters the gas-liquid separator 124. The gas-liquid separated refrigerant gas is sucked into the compressor 111 through the suction port. A complete refrigeration cycle is completed and such refrigeration cycle can be performed without interruption in order to achieve the target refrigeration temperature.
The control method for a refrigeration and freezing unit of the present invention will be described below based on the above-described refrigeration and freezing unit. Fig. 2 is a flow chart of a control method for a refrigeration and freezing unit according to the present invention. As shown in fig. 2, the control method begins when the refrigeration-freezer unit 1 is powered on. In step S1, the indoor temperature is detected. The indoor temperature is an indoor ambient temperature, such as a warehouse temperature. The indoor temperature may be a temperature measured from an indoor unit air inlet or other suitable location in the room. Then, the control method proceeds to step S2 to determine whether the indoor temperature reaches a preset startup temperature value. The preset startup temperature value is, for example, 2 deg.C, -10 deg.C, etc. The specific preset starting temperature value is determined according to actual requirements. When the indoor temperature reaches the preset startup temperature value, the indoor solenoid valve 213 of the refrigeration and freezing unit 1 is closed. In the case where the indoor unit 21 has an indoor dry contact terminal, and thus a dry contact signal line connection is made between the outdoor unit group 11 and the indoor unit 21, when the indoor solenoid valve 213 is closed, the indoor dry contact terminal is closed, and thus a dry contact signal is generated between the outdoor unit group 11 and the indoor unit 21. In contrast, in the case where the indoor unit 21 has no dry contact terminal, the outdoor dry contact forms a short circuit, and there is a dry contact signal at this time. Therefore, when the indoor solenoid valve 213 is closed, the dry contact signal is in the on state.
As shown in fig. 2, after the indoor solenoid valve 213 is closed, the control method proceeds to step S4 to determine whether the outdoor unit set 11 is powered on for the first time. When it is determined that the outdoor unit group 11 is not powered on for the first time, it is determined whether the previous shutdown memory of the compressor 111 is the signal shutdown memory or the pressure shutdown memory (step S5). When it is determined that the previous shutdown memory is the signal shutdown memory, the compressor 111 is controlled to be started in the first startup mode (step S6). When it is determined that the previous shutdown memory is the pressure shutdown memory, the compressor 111 is controlled to be started in the second start-up mode. Therefore, the control method can determine the starting mode adopted by the next starting according to the previous actual stopping mode.
Fig. 3 is a start-up flow chart of the control method for the refrigeration and freezing unit according to the embodiment of the invention. As shown in fig. 3, after the control method is started, the indoor temperature is detected (step S1), and it is determined whether the indoor temperature is equal to or greater than a preset turn-on temperature value (step S2). If the indoor temperature is less than the preset startup temperature value, control returns to step S1. If the indoor temperature is equal to or higher than the preset startup temperature value, the control method proceeds to step S3 to close the indoor solenoid valve 213. As mentioned above, the dry contact signal is in the on state once the indoor solenoid valve 213 is closed. Then, the control method proceeds to step S4, where it is determined whether the outdoor unit 11 is powered on for the first time. If the outdoor unit set 11 is first powered up, the first start-up mode is implemented, and therefore the control method proceeds to step S61 where the current live shutdown period of the compressor 111 is determined. Then, in step S62, the current electrification shutdown time period is compared with a predetermined shutdown time period. The predetermined shutdown period may be a minimum powered-on shutdown period of the compressor, such as 4 minutes, 5 minutes, or the like as appropriate. The preset shutdown time can be calculated according to the minimum start-stop service life of the compressor specified by the specification of the compressor. When the current electrified shutdown time period of the compressor 111 is less than the predetermined shutdown time period, the control method returns to step S61 to continue determining the current electrified shutdown time period of the compressor 111. When the current electrified shutdown period of the compressor 111 is greater than or equal to the predetermined shutdown period, the compressor is directly started (step S63).
As shown in fig. 3, when the outdoor unit 11 is not first powered on, the control method proceeds to step S51 to determine whether the previous shutdown memory is the signal shutdown memory. If the last shutdown memory was the signaled shutdown memory, the control method implements a first startup mode, i.e., determines the current live shutdown duration of the compressor 111. Then, in step S62, the current electrification shutdown time period is compared with a predetermined shutdown time period. When the current electrified shutdown time period of the compressor 111 is less than the predetermined shutdown time period, the control method returns to step S61 to continue determining the current electrified shutdown time period of the compressor 111. When the current electrified shutdown period of the compressor 111 is greater than or equal to the predetermined shutdown period, the compressor is directly started (step S63).
As shown in fig. 3, when the last shutdown memory is not the signal shutdown memory, it may be determined to be the pressure shutdown memory (step S52). Then, the control method proceeds to step S71 and step S72, respectively. In step S71, the current electrified shutdown time period of the compressor 111 is determined. Then, in step S73, the current electrification shutdown time period is compared with a predetermined shutdown time period. When the current electrified shutdown time period of the compressor 111 is less than the predetermined shutdown time period, the control method returns to step S71 to continue determining the current electrified shutdown time period of the compressor 111. In step S72, the current suction pressure of the compressor 111 is detected. Then, in step S74, the current suction pressure is compared with a predetermined starting pressure value. When the current suction pressure of the compressor 111 is less than the predetermined starting pressure value, the control method returns to step S72 to continue to determine the current suction pressure of the compressor 111. The compressor 111 is started only when the current electrified shutdown period of the compressor 111 is greater than or equal to the predetermined shutdown period and the current suction pressure is greater than or equal to the predetermined startup pressure value (step S75). The control method fully considers two conditions of a signal line and a no-signal line between the outdoor unit 11 and the indoor unit 21, when the refrigeration and freezing unit is started after being stopped with electricity, firstly, the mode (stop memory) of the previous electrified stop is detected and judged, and then, the starting judgment is carried out, so that the aim of accurately starting the refrigeration and freezing unit can be fulfilled.
Fig. 4 is a stop flow diagram of an embodiment of the control method for a refrigeration and freezing assembly of the present invention. As shown in fig. 4, after the control method is started, the indoor temperature is detected (step S1), and it is determined whether the indoor temperature is equal to or less than a preset shutdown temperature value (step S8). If the indoor temperature is greater than the preset shutdown temperature value, control returns to step S1. If the indoor temperature is equal to or less than the preset shutdown temperature value, indicating that the indoor temperature has reached the predetermined target temperature, the control method proceeds to step S9 to turn off the indoor solenoid valve 213. Then, the control method proceeds to step S10 to determine whether the dry contact signal is off. When the indoor solenoid valve 213 is turned off when a signal line is connected between the outdoor unit 11 and the indoor unit 21, the dry contact signal is turned off. Alternatively, in the case of a signal line connection between the outdoor unit 11 and the indoor unit 21, the dry contact signal is also turned off when the temperature of the coil of the indoor unit or the indoor heat exchanger is manually turned off to reach a set value. Therefore, the dry contact signal is turned off by the indoor unit. On the contrary, under the condition that the outdoor unit is electrified, if the outdoor dry contact is short-circuited, the dry contact signal is not disconnected. If it is determined that the dry contact signal is turned off, the control method proceeds to step S11 to directly stop the compressor 111 and generate a signal stop memory. The signal shutdown memory may be stored in a controller of the outdoor unit for a next startup control of the outdoor unit.
As shown in fig. 4, if the dry contact signal is not off, the control method proceeds to step S20 to determine whether the precision shutdown mode is masked. When the refrigerating and freezing unit is in the initial starting stage, the oil return process, part of protection control stages and the like, the precision shutdown mode is shielded. If the precision shutdown mode is masked, the control method proceeds to step S21 to control the compressor to enter the lowest pressure shutdown mode. In the lowest pressure stop mode, the control method proceeds to step S22 to detect a current suction pressure of the compressor. Then, in step S23, it is determined whether or not the current suction pressure is equal to or less than a predetermined minimum shutdown pressure value. If the current suction pressure is greater than the predetermined minimum shutdown pressure value, control returns to step S22 to continue sensing the current suction pressure of the compressor. If the current suction pressure is less than or equal to the predetermined minimum shutdown pressure value, control proceeds to step S25 to shutdown the compressor and generate a pressure shutdown memory. The predetermined minimum shutdown pressure value may be determined based on the evaporation temperature usage range of the refrigeration and freezing assembly. For example, a minimum evaporating temperature of-20 ℃ is used, corresponding to a saturation pressure of 0.3MPa, and the predetermined minimum shut-down pressure value may be set to a pressure value lower than 0.3MPa, for example 0.2 MPa. If the lowest shutdown pressure value is set to 0.3MPa, low-pressure early warning risks can be caused, and then the problem of low-pressure shutdown is caused. The pressure shutdown memory may be stored in a controller of the outdoor unit for a next startup control of the outdoor unit.
As shown in fig. 4, if the precision stop mode is not masked, the control method proceeds to step S26 to control the compressor to enter the precision stop mode. In the precision stop mode, the control method proceeds to step S27 to detect the current suction pressure of the compressor. Then, in step S28, it is determined whether or not the current suction pressure is equal to or less than a predetermined precision stop pressure value. If the current suction pressure is greater than the predetermined shutdown pressure value, control returns to step S27 to continue sensing the current suction pressure of the compressor. If the current suction pressure is less than or equal to the predetermined precision shutdown pressure value, control proceeds to step S29 to shutdown the compressor and generate a pressure shutdown memory. The pressure shutdown memory may be stored in a controller of the outdoor unit for a next startup control of the outdoor unit. The predetermined precision shutdown pressure value is higher than the predetermined minimum shutdown pressure value and is also determined according to the evaporation temperature use range of the refrigeration and freezing unit. For example, when the lowest evaporation temperature is used at-20 ℃, the corresponding saturation pressure is 0.3 MPa. The accuracy is set to 2 deg.c and the deviation design value for accuracy shutdown, e.g., 3 deg.c, then the accuracy shutdown pressure value may be 0.23 MPa. The control method sets a triple shutdown logic, and can ensure that the refrigeration and freezing unit can be normally and accurately shut down in each operation stage.
So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.
Claims (10)
1. A control method for a refrigerating and freezing unit is characterized in that the refrigerating and freezing unit comprises an outdoor unit and an indoor unit which can be interconnected, the outdoor unit is provided with an outdoor dry contact terminal, the outdoor dry contact terminal forms a short circuit or is connected with an indoor dry contact terminal of the indoor unit through a signal wire, and after the refrigerating and freezing unit is powered on, the control method comprises the following steps:
detecting the indoor temperature;
judging whether the indoor temperature reaches a preset starting temperature value or not;
when the indoor temperature reaches the preset starting temperature value, closing an indoor electromagnetic valve of the refrigerating and freezing unit;
judging whether the outdoor unit is powered on for the first time;
when the outdoor unit is not powered on for the first time, judging whether the previous shutdown memory of the compressor is signal shutdown memory or pressure shutdown memory;
when the previous shutdown memory is the signal shutdown memory, controlling the compressor to start in a first starting mode; and is
And when the previous shutdown memory is the pressure shutdown memory, controlling the compressor to start in a second starting mode.
2. A control method for a refrigeration and freezing assembly as claimed in claim 1, wherein in the first mode of operation the control method comprises:
determining a current live shutdown duration of the compressor;
and starting the compressor when the current electrified shutdown time reaches a preset shutdown time.
3. A control method for a refrigeration and freezing assembly as claimed in claim 1, wherein in the second mode of operation the control method comprises:
determining the current electrified shutdown time length of the compressor and detecting the current suction pressure of the compressor;
and starting the compressor when the current electrified shutdown time reaches a preset shutdown time and the current suction pressure reaches a preset starting pressure value.
4. A control method for a refrigeration and freezing assembly as claimed in claim 1, wherein the compressor is controlled to start in the first start-up mode when the outdoor assembly is first powered up.
5. A control method for a refrigeration and freezing unit according to claim 1,
short circuit of the outdoor dry contact terminal generates a dry contact signal; or
The outdoor dry contact terminal and the indoor dry contact terminal of the indoor unit are connected through the signal line, and the indoor dry contact terminal and the indoor solenoid valve are combined together such that the dry contact signal is generated in the signal line when the indoor solenoid valve is closed.
6. A control method for a refrigeration and freezing assembly as set forth in claim 5 further comprising:
judging whether the indoor temperature reaches a preset shutdown temperature value or not;
when the indoor temperature reaches the preset shutdown temperature value, disconnecting the indoor electromagnetic valve;
judging whether the dry contact signal is disconnected or not;
when the dry contact signal is off, the compressor is shut down and the signal shutdown memory is generated.
7. A control method for a refrigeration and freezing assembly as claimed in claim 6, wherein when the dry contact signal is not off, the control method comprises:
judging whether the precision shutdown mode is shielded or not;
controlling the compressor to enter a lowest pressure shutdown mode when the precision shutdown mode is masked; and is
Controlling the compressor to enter a precision shutdown mode when the precision shutdown mode is not masked.
8. A control method for a refrigeration and freezing assembly as set forth in claim 7 wherein in the lowest pressure shutdown mode, the control method includes:
detecting a current suction pressure of the compressor;
comparing the current suction pressure to a predetermined minimum shutdown pressure value;
when the current suction pressure is less than or equal to the predetermined minimum shutdown pressure value, the compressor is shutdown and the pressure shutdown memory is generated.
9. A control method for a refrigeration and freezing assembly as claimed in claim 7, wherein in the precision shutdown mode, the control method comprises:
detecting a current suction pressure of the compressor;
comparing the current suction pressure with a preset precision shutdown pressure value;
when the current suction pressure is less than or equal to the precision shutdown pressure value, the compressor is shut down and the pressure shutdown memory is generated.
10. A refrigerator-freezer unit, characterized in that the refrigerator-freezer unit comprises a compressor and the compressor is controlled using a control method according to any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110592704.2A CN113418328B (en) | 2021-05-28 | 2021-05-28 | Control method for refrigerating and freezing unit and refrigerating and freezing unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110592704.2A CN113418328B (en) | 2021-05-28 | 2021-05-28 | Control method for refrigerating and freezing unit and refrigerating and freezing unit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113418328A true CN113418328A (en) | 2021-09-21 |
| CN113418328B CN113418328B (en) | 2023-02-03 |
Family
ID=77713236
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110592704.2A Active CN113418328B (en) | 2021-05-28 | 2021-05-28 | Control method for refrigerating and freezing unit and refrigerating and freezing unit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113418328B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114738939A (en) * | 2022-03-04 | 2022-07-12 | 青岛海尔空调电子有限公司 | Method and device for controlling outdoor unit, outdoor unit and storage medium |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6711445B1 (en) * | 1998-12-17 | 2004-03-23 | Kysor/Warren | Refrigeration control apparatus and method |
| CN1862130A (en) * | 2005-05-09 | 2006-11-15 | 海尔集团公司 | Controlling method of safety stop of air conditioner |
| CN1906450A (en) * | 2004-09-13 | 2007-01-31 | 大金工业株式会社 | Refrigerating device |
| CN101135487A (en) * | 2006-08-29 | 2008-03-05 | 海尔集团公司 | Device for preventing compressor from start-up with liquid of multiple air-conditioning unit |
| CN102116550A (en) * | 2009-12-31 | 2011-07-06 | 丹佛斯（上海）自动控制有限公司 | Evaporation control device used in refrigerating system |
| CN102788404A (en) * | 2012-07-31 | 2012-11-21 | 宁波奥克斯电气有限公司 | Control method for preventing direct current variable frequency air conditioner from accidentally shutting down due to low voltage |
| JP2016003848A (en) * | 2014-06-19 | 2016-01-12 | 日立アプライアンス株式会社 | Air conditioning system and control method for the same |
| CN110173854A (en) * | 2019-05-29 | 2019-08-27 | 青岛海尔空调电子有限公司 | A kind of air conditioner low-temperature heating starting control method and air conditioner |
-
2021
- 2021-05-28 CN CN202110592704.2A patent/CN113418328B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6711445B1 (en) * | 1998-12-17 | 2004-03-23 | Kysor/Warren | Refrigeration control apparatus and method |
| CN1906450A (en) * | 2004-09-13 | 2007-01-31 | 大金工业株式会社 | Refrigerating device |
| CN1862130A (en) * | 2005-05-09 | 2006-11-15 | 海尔集团公司 | Controlling method of safety stop of air conditioner |
| CN101135487A (en) * | 2006-08-29 | 2008-03-05 | 海尔集团公司 | Device for preventing compressor from start-up with liquid of multiple air-conditioning unit |
| CN102116550A (en) * | 2009-12-31 | 2011-07-06 | 丹佛斯（上海）自动控制有限公司 | Evaporation control device used in refrigerating system |
| CN102788404A (en) * | 2012-07-31 | 2012-11-21 | 宁波奥克斯电气有限公司 | Control method for preventing direct current variable frequency air conditioner from accidentally shutting down due to low voltage |
| JP2016003848A (en) * | 2014-06-19 | 2016-01-12 | 日立アプライアンス株式会社 | Air conditioning system and control method for the same |
| CN110173854A (en) * | 2019-05-29 | 2019-08-27 | 青岛海尔空调电子有限公司 | A kind of air conditioner low-temperature heating starting control method and air conditioner |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114738939A (en) * | 2022-03-04 | 2022-07-12 | 青岛海尔空调电子有限公司 | Method and device for controlling outdoor unit, outdoor unit and storage medium |
| CN114738939B (en) * | 2022-03-04 | 2024-02-23 | 青岛海尔空调电子有限公司 | Method and device for controlling outdoor unit, outdoor unit and storage medium |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113418328B (en) | 2023-02-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110914609B (en) | Control method for an economizer of a transport refrigeration unit | |
| CN109668350B (en) | High-stability heat pump system | |
| US5749237A (en) | Refrigerant system flash gas suppressor with variable speed drive | |
| CN1982808A (en) | Refrigerating apparatus | |
| US9683767B2 (en) | Cooling system and control method thereof | |
| US10508845B2 (en) | Refrigeration cycle system | |
| JP2012072920A (en) | Refrigeration apparatus | |
| CN106931545B (en) | Heat pump enthalpy-spraying system, control method thereof and air conditioner | |
| CN113465129A (en) | Control method of air conditioner and air conditioner | |
| US11274851B2 (en) | Air conditioning apparatus | |
| CN114294715A (en) | Multi-split air-supplementing enthalpy-increasing system with economizer and control method thereof | |
| CN113418328B (en) | Control method for refrigerating and freezing unit and refrigerating and freezing unit | |
| CN113375356A (en) | Control method of multi-split refrigerating and freezing unit and multi-split refrigerating and freezing unit | |
| CN113418329A (en) | Control method of refrigeration and freezing unit and refrigeration and freezing unit | |
| JP6611929B2 (en) | Refrigeration equipment | |
| KR20100120323A (en) | Chiller system | |
| CN113432269A (en) | Control method of refrigeration and freezing unit and refrigeration and freezing unit | |
| CN106796056B (en) | Refrigeration cycle device | |
| US20220186988A1 (en) | Refrigeration apparatus | |
| EP2153138A1 (en) | Refrigerating system and method for controlling compressor sets in such a refrigerating system | |
| JP7411929B2 (en) | Refrigeration equipment | |
| CN113513852A (en) | Cooling system, refrigeration equipment and cooling method | |
| CN113432343B (en) | Oil return control method of refrigeration and freezing unit and refrigeration and freezing unit | |
| KR20210094213A (en) | An air conditioning apparatus | |
| CN113418327B (en) | Oil return control method of refrigeration and freezing unit and refrigeration and freezing unit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |