CN210569394U - Air conditioner - Google Patents

Abstract

The air conditioner is provided with: a refrigerant circuit including a compressor; and a plurality of accumulators connected in parallel to a suction port of the compressor in the refrigerant circuit, the plurality of accumulators being disposed in a vertical direction with respect to the ground.

Description

Air conditioner

Technical Field

The utility model relates to an air conditioning equipment who has the structure that is connected with the accumulator in the refrigerant return circuit.

Background

Conventionally, an air conditioning apparatus such as a multi-type air conditioner for a building performs a cooling operation or a heating operation by circulating a refrigerant between an outdoor unit, which is a heat source unit disposed outdoors, and an indoor unit disposed indoors, for example.

In a compressor of an air conditioner, an accumulator is connected to a suction port side of refrigerant. The accumulator is an example of a container that separates refrigerant into gas and liquid and stores the liquid refrigerant. In an air conditioner, an accumulator is connected to a pipe connecting an evaporator and a compressor, and thus, even when refrigerant is not completely evaporated in the evaporator, the refrigerant is prevented from flowing into the compressor while remaining in a liquid state. When the compressor compresses the liquid refrigerant, the compressor fails, but the accumulator prevents the failure from occurring.

The size of the accumulator volume is mainly determined by the amount of refrigerant enclosed in the air conditioning apparatus. The smaller the volume of each energy storage device, the lighter the energy storage device is and the cheaper it can be manufactured. On the other hand, if one accumulator is to have a large capacity, the thickness of the casing needs to be increased in order to increase the strength against the refrigerant pressure. In this case, the manufacturing cost is increased due to an increase in material cost and processing cost.

An example of a countermeasure is disclosed in patent document 1. Patent document 1 discloses an air conditioning apparatus having a structure in which two accumulators having the same volume are connected in parallel to a refrigerant circuit.

Patent document 1: international publication No. 2011/099056

In the air conditioning apparatus disclosed in patent document 1, if two accumulators are installed on the same floor surface in the outdoor unit, the installation area occupied by one accumulator is required to be twice as large as the installation area occupied by one accumulator. If the capacity of one accumulator is increased to two times while maintaining the installation area for one accumulator, the manufacturing cost of the accumulator increases as described above.

SUMMERY OF THE UTILITY MODEL

The present invention has been made to solve the above-described problems, and provides an air conditioner that can increase the capacity of an accumulator while suppressing an increase in the installation area of the accumulator.

The utility model discloses an air conditioning device has: a refrigerant circuit including a compressor; and two accumulators connected in parallel to a suction port of the compressor in the refrigerant circuit, the two accumulators being provided in a vertical direction with respect to a ground surface such that one of the two accumulators is positioned above the other accumulator.

Preferably, there is also a pressure equalizing tube connecting the interiors of the two energy stores to one another.

Preferably, in each of the two accumulators, a nozzle of the pressure equalizing pipe in the accumulator is located at a position higher than a nozzle of an outflow pipe in the accumulator through which the refrigerant flows out from the accumulator to the compressor.

Preferably, the height of the orifice of the pressure equalizing tube in the accumulator in the vertical direction is different from the height of the orifice of the suction tube in the accumulator through which the refrigerant flows from the refrigerant circuit to the accumulator in the vertical direction.

Preferably, the orifice of the pressure equalizing pipe in the energy accumulator is located within a preset range from the center of the energy accumulator in a horizontal plane.

Preferably, the pressure equalizer is a structure that extends linearly from one accumulator to the other accumulator in the vertical direction among the two accumulators.

Preferably, the refrigerant circuit further includes a T-branch pipe connected to the refrigerant circuit, and including two branch portions that branch horizontally in two directions, the two branch portions being connected to two suction pipes through which the refrigerant flows into the two accumulators, and branching the refrigerant flowing from the refrigerant circuit to the two accumulators.

Preferably, the refrigerant compressor further includes a T-junction pipe that joins two outflow pipes through which the refrigerant flows out of the two accumulators and is connected to a suction port of the compressor via one refrigerant pipe.

Preferably, the volumes of the two accumulators storing refrigerant are different from each other.

The utility model discloses a plurality of accumulators set up in the vertical direction, consequently store the volume increase of refrigerant to can restrain the increase of setting up the area that the accumulator occupy.

Drawings

Fig. 1 is a refrigerant circuit diagram showing an example of a configuration of an air conditioner according to embodiment 1 of the present invention.

Fig. 2 is a refrigerant circuit diagram for explaining an operation of the air-conditioning apparatus shown in fig. 1 in a cooling operation.

Fig. 3 is a refrigerant circuit diagram for explaining an operation of the air-conditioning apparatus shown in fig. 1 in a heating operation.

Fig. 4 is a schematic diagram showing an example of arrangement of the accumulator shown in fig. 1.

Fig. 5A is a side view showing one configuration example of the accumulator shown in fig. 1.

Fig. 5B is a top view of the accumulator shown in fig. 5A.

Fig. 5C is a side view of the accumulator shown in fig. 5A, viewed from a different direction than fig. 5A.

Fig. 6 is a perspective view showing one configuration example of the suction pipe in the first accumulator shown in fig. 5B.

Fig. 7 is a plan view showing a configuration of modification 1 of the accumulator shown in fig. 5A to 5C.

Fig. 8 is a side view showing the structure of modification 2 of the accumulator shown in fig. 5A to 5C.

Fig. 9 is a side view showing an arrangement example in the case where three accumulators are provided in the accumulator shown in fig. 5C.

Fig. 10 is a refrigerant circuit diagram showing another configuration example of the air conditioner according to embodiment 1 of the present invention.

Detailed Description

Embodiment mode 1

The structure of the air conditioner of embodiment 1 will be explained. Fig. 1 is a refrigerant circuit diagram showing an example of a configuration of an air conditioner according to embodiment 1 of the present invention. In fig. 1, there is a case where the relative size difference between the devices is different from the actual one.

As shown in fig. 1, the air conditioner 1 includes an outdoor unit 10 and a plurality of indoor units 20a to 20 d. The outdoor unit 10 is an example of a heat source unit, and the indoor units 20a to 20d are examples of load-side devices. The outdoor unit 10 includes a compressor 11, an oil separator 12, a flow path switching valve 13, a heat source side heat exchanger 14, an accumulator 15, an oil return capillary tube 16, and a control unit 35. The compressor 11, the oil separator 12, the flow path switching valve 13, the heat source side heat exchanger 14, the accumulator 15, and the oil return capillary tube 16 are connected by a refrigerant pipe 30 b.

The indoor unit 20a includes a load-side heat exchanger 22a and an expansion device 21 a. The indoor unit 20b includes a load-side heat exchanger 22b and an expansion device 21 b. The indoor unit 20c includes a load-side heat exchanger 22c and an expansion device 21 c. The indoor unit 20d includes a load-side heat exchanger 22d and an expansion device 21 d. In the indoor unit 20a, the load-side heat exchanger 22a and the expansion device 21a are connected via the refrigerant pipe 30 a. The other indoor units 20b to 20d have the same configuration as the indoor unit 20a, and therefore, detailed description thereof is omitted. The refrigerant circuit 2 is configured by the compressor 11, the flow path switching valve 13, the heat source side heat exchanger 14, the load side heat exchangers 22a to 22d and the expansion devices 21a to 21d, and refrigerant pipes 30a and 30b connecting these devices.

As shown in fig. 1, the outdoor unit 10 and the indoor units 20a to 20d are connected to each other via refrigerant pipes 30a and 30 b. Specifically, the load-side heat exchangers 22a to 22d are connected to the flow path switching valve 13 of the outdoor unit 10 via the refrigerant pipe 30 b. The expansion devices 21a to 21d are connected to the heat source side heat exchanger 14 via a refrigerant pipe 30 a.

Fig. 1 shows a case where there are four indoor units, but the number of indoor units is not limited to four. In fig. 1, the control unit 35 is provided in the outdoor unit 10, but the control unit 35 may be provided in any of the indoor units 20a to 20 d.

The configuration of each device of the air conditioner 1 shown in fig. 1 will be described. The accumulator 15 separates the refrigerant into gas and liquid, and stores excess refrigerant in liquid form. The accumulator 15 prevents the refrigerant from flowing into the compressor 11 in a liquid state. The energy storage 15 has a first energy storage 15a and a second energy storage 15b connected in parallel. The details of the structures of the first energy storage 15a and the second energy storage 15b will be described later.

The compressor 11 has a refrigerant suction port connected to the accumulator 15 and a refrigerant discharge port connected to the oil separator 12. The compressor 11 compresses the refrigerant sucked from the accumulator 15 and discharges the compressed refrigerant to the oil separator 12 side. The oil separator 12 separates refrigerating machine oil from the refrigerant discharged from the compressor 11. The oil return capillary tube 16 functions to make the refrigerant oil returned from the oil separator 12 to the compressor 11 as free as possible from the refrigerant. The flow path switching valve 13 switches the flow path of the refrigerant according to the operating state of the air conditioner 1. The flow path switching valve 13 is, for example, a four-way switching valve.

The heat source side heat exchanger 14 exchanges heat between outdoor air and the refrigerant. The heat source side heat exchanger 14 functions as a condenser when the air conditioner 1 performs a cooling operation, and functions as an evaporator when the air conditioner 1 performs a heating operation. The load-side heat exchangers 22a to 22d exchange heat between the indoor air and the refrigerant. The load-side heat exchangers 22a to 22d function as evaporators when the air conditioner 1 performs a cooling operation, and function as condensers when the air conditioner 1 performs a heating operation. The expansion devices 21a to 21d reduce the pressure of the high-pressure refrigerant liquefied in the condenser to the pressure of the evaporator, and evaporate the refrigerant in the evaporator.

The control unit 35 is, for example, a microcomputer. The control unit 35 is connected to the compressor 11, the flow path switching valve 13, and the expansion devices 21a to 21d via signal lines not shown in the drawings. The control unit 35 controls the refrigeration cycle by adjusting the rotational frequency of the compressor 11, the flow path of the flow path switching valve 13, and the throttle amounts of the throttle devices 21a to 21 d. The refrigerant is, for example, R410A. The type of refrigerant is not limited to R410A.

A fan not shown in the drawings may be provided in the heat source side heat exchanger 14 and a fan not shown in the drawings may be provided in the load side heat exchangers 22a to 22 d. In this case, the control unit 35 may control the rotational frequency of the fans. Further, a sensor for measuring temperature and a sensor for measuring pressure may be provided in the refrigerant circuit 2, and the controller 35 may adjust the degree of supercooling and the degree of superheat based on the measurement values of the plurality of sensors.

Next, the operation of the air conditioner 1 according to embodiment 1 will be described. First, an operation of the air conditioner 1 during the cooling operation will be described. Fig. 2 is a refrigerant circuit diagram for explaining an operation of the air-conditioning apparatus shown in fig. 1 in a cooling operation. The direction of the refrigerant flow is indicated by arrows in fig. 2.

First, when the high-temperature and high-pressure refrigerant discharged from the compressor 11 flows into the oil separator 12, the refrigerating machine oil is separated from the refrigerant in the oil separator 12. The refrigerant oil separated here is returned to the suction side of the compressor 11 through the oil return capillary tube 16, and the inside of the compressor 11 is lubricated again. The high-temperature and high-pressure refrigerant having passed through the oil separator 12 flows into the heat source side heat exchanger 14 through the flow path switching valve 13, and releases its heat to the outside to be liquefied. The refrigerant flows out of the heat source side heat exchanger 14 in a liquid state. In this way, the heat-source-side heat exchanger 14 functions as a condenser during the cooling operation.

Then, the refrigerant in a high-pressure state and having a reduced temperature flows from the outdoor unit 10 into the indoor units 20a to 20d through the refrigerant pipe 30 a. The refrigerant flowing into the indoor units 20a to 20d is decompressed by the expansion devices 21a to 21d, and enters a low-temperature and low-pressure state of a gas-liquid two-phase state. The low-temperature and low-pressure refrigerant flows into the load-side heat exchangers 22a to 22d, exchanges heat with indoor air to become low-pressure gas refrigerant, and flows out of the indoor units 20a to 20 d.

Although not shown in the drawings, temperature sensors are attached to the refrigerant outlets and the refrigerant inlets of the load-side heat exchangers 22a to 22d, respectively. The control unit 35 adjusts the throttle amounts of the throttle devices 21a to 21d so that the degree of superheat (outlet temperature — inlet temperature) is about 2 to 5 ° based on the measurement values of these temperature sensors. In this way, the load-side heat exchangers 22a to 22d function as evaporators during the cooling operation.

The refrigerant that has flowed out of the indoor units 20a to 20d and becomes low-pressure gas flows into the outdoor unit 10 through the refrigerant pipe 30 b. The refrigerant flowing into the outdoor unit 10 passes through the flow switching valve 13 and flows into the first accumulator 15a and the second accumulator 15 b. The refrigerant flowing into the first accumulator 15a and the second accumulator 15b is separated into gas and liquid, and the gas refrigerant is sucked into the compressor 11 again.

Next, an operation in the heating operation of the air conditioner 1 according to embodiment 1 will be described. Fig. 3 is a refrigerant circuit diagram for explaining an operation of the air-conditioning apparatus shown in fig. 1 in a heating operation. The direction of the refrigerant flow is indicated by arrows in fig. 3.

The high-temperature and high-pressure refrigerant discharged from the compressor 11 is separated into the refrigerant oil by the oil separator 12, and then flows out of the oil separator 12. The high-temperature and high-pressure refrigerant having passed through the oil separator 12 passes through the refrigerant pipe 30b by the flow path switching valve 13 and flows into the indoor units 20a to 20 d. The high-temperature and high-pressure refrigerant flowing into the indoor units 20a to 20d releases its heat into the room in the load side heat exchangers 22a to 22d, and liquefies. The refrigerant flows out of the load side heat exchangers 22a to 22d in a liquid state. The refrigerant in a liquid state flowing out of the load side heat exchangers 22a to 22d passes through the expansion devices 21a to 21d, is depressurized, and becomes a low-temperature, low-pressure, two-phase gas-liquid refrigerant. The refrigerant in a gas-liquid two-phase state flows into the outdoor unit 10 through the refrigerant pipe 30 a.

Although not shown in the drawings, a pressure sensor is attached to the refrigerant outlet of the compressor 11, and a temperature sensor is attached to the refrigerant outlet of the load-side heat exchangers 22a to 22 d. The control unit 35 adjusts the throttle amounts of the throttle devices 21a to 21d so that the degree of supercooling (saturation temperature-outlet temperature converted from pressure) becomes about 2 to 5 ° based on the measurement values of the pressure sensor and the temperature sensor. In this way, during the heating operation, the load-side heat exchangers 22a to 22d function as condensers.

The low-temperature, low-pressure refrigerant flowing into the outdoor unit 10 flows into the heat source side heat exchanger 14, exchanges heat with ambient air, and gradually increases in dryness as it enters the heat source side heat exchanger 14. At the outlet of the heat source side heat exchanger 14, the refrigerant flows out in a gas-liquid two-phase state with high dryness. The refrigerant flowing out of the heat source side heat exchanger 14 passes through the flow switching valve 13 and flows into the first accumulator 15a and the second accumulator 15 b. The refrigerant flowing into the first accumulator 15a and the second accumulator 15b is separated into gas and liquid, and the gas refrigerant is sucked into the compressor 11 again. In this way, the heat source side heat exchanger 14 functions as an evaporator during the heating operation.

Next, the structure of the accumulator 15 in embodiment 1 will be described in detail. In the case where the refrigerant is, for example, R410A, the design pressure of the accumulator is 2.3 MPa. Thus, in order to produce an energy store which can withstand higher pressures, the wall thickness of the vessel must be increased. In an air conditioning apparatus having a short length of refrigerant piping, as in a household room air conditioner, the capacity of the accumulator may be small because the amount of extra refrigerant is small. On the other hand, in a system such as a multi-type air conditioner for a building in which the number of connected indoor units is large and the length of refrigerant piping is also long, the amount of extra refrigerant is large, and the capacity required for the accumulator becomes several tens of liters. The production of containers with large volumes and high pressure resistance is not only technically difficult, but also leads to an increase in the unit price of the energy store.

As a structure for sufficiently securing a pressure resistance against the refrigerant pressure and reducing the product cost, a structure may be considered in which two or more accumulators are connected in parallel to the refrigerant circuit. However, if two or more accumulators are installed on the same ground, the installation area of the accumulators is increased as compared with the case of one accumulator, as described in the subject column. For example, if two accumulators are installed on the floor of the casing of the outdoor unit 10, the installation area of one accumulator needs to be twice as large as the installation area of one accumulator.

Therefore, in embodiment 1, two or more accumulators connected in parallel are arranged in the vertical direction with respect to the ground. Fig. 4 is a schematic diagram showing an example of arrangement of the accumulator shown in fig. 1. Hereinafter, a case where two accumulators are used will be described, but three or more accumulators may be used.

As shown in fig. 4, the second energy storage 15b and the first energy storage 15a are sequentially disposed in a vertical direction (a direction of an arrow of a Z axis) with respect to the ground of the outdoor unit 10. In the arrangement shown in fig. 4, the first energy store 15a is arranged above the second energy store 15b at a distance from the second energy store 15 b. As shown in fig. 4, for example, the distance is a distance necessary for surrounding the suction pipe 41b and the discharge pipe 42b between the two accumulators and attaching these pipes to the upper surface of the second accumulator 15 b.

As shown in fig. 4, in the first accumulator 15a, an inlet pipe 41a is connected to an inlet side into which the refrigerant flows from the flow path switching valve 13 via the refrigerant pipe 30b, and an outlet pipe 42a is connected to an outlet side from which the refrigerant flows out to the compressor 11. In the second accumulator 15b, an intake pipe 41b is connected to the refrigerant inlet side, and an outlet pipe 42b is connected to the refrigerant outlet side. The first energy storage device 15a may be supported by the second energy storage device 15b provided on the floor surface of the outdoor unit 10 via the suction pipes 41a and 41b and the discharge pipes 42a and 42b, or may be supported on the wall of the casing of the outdoor unit 10 or the floor surface via a holding unit, which is not shown in the drawings. As the holding means attached to the wall, for example, there is a ratchet belt.

In the air conditioning apparatus 1 according to embodiment 1, as shown in fig. 4, a large required volume can be ensured by providing a plurality of small-volume accumulators. In addition, by increasing the number of small-volume accumulators to be manufactured, not only can the manufacturing cost per 1 unit of small-volume accumulators be reduced, but also the manufacturing cost can be further reduced in the entire number of small-volume accumulators by the mass production effect. Since the plurality of energy storages are provided in the vertical direction, the installation area of the energy storages with respect to the floor surface of the outdoor unit 10 may be an area corresponding to the installation area of the energy storage in the lowermost layer. As a result, even if the volume of the entire accumulator increases, the installation area of the accumulator can be suppressed from increasing.

In the installation example shown in fig. 4, it is considered that the gas-liquid two-phase refrigerant flowing from the flow path switching valve 13 into the accumulator 15 is equally divided into the suction pipe 41a and the suction pipe 41b when the gas ratio is larger than the liquid ratio, for example. However, when the ratio of the liquid to the refrigerant flowing into the accumulator 15 is larger than that of the gas, it is considered that the amount of the refrigerant accumulated in the second accumulator 15b is larger than that in the first accumulator 15 a. In this case, the liquid refrigerant may overflow in the second accumulator 15 b.

In the installation example shown in fig. 4, the suction pipe 41b is longer than the suction pipe 41a by comparing the lengths of the suction pipes 41a and 41b from the branch point of the refrigerant pipe 30 b. The suction pipe 41b is larger than the suction pipe 41a in pressure loss in the piping. Therefore, even if the ratio of the gas to the liquid is the same for the refrigerant flowing from the flow path switching valve 13 into the accumulator 15, it is considered that the amount of the refrigerant accumulated in the first accumulator 15a is larger than that in the second accumulator 15 b. In this case, the liquid refrigerant may overflow in the first accumulator 15 a.

In the case where two accumulators are connected in parallel as in the example of arrangement shown in fig. 4, if the refrigerant and the refrigerating machine oil are not distributed evenly to the two accumulators, the refrigerant and the refrigerating machine oil are biased toward one accumulator, and the refrigerant and the refrigerating machine oil overflow at one accumulator. In the case where three or more accumulators are provided, there is a possibility that the refrigerant and the refrigerating machine oil may overflow from a part of the accumulators in the three or more accumulators.

In the installation example shown in fig. 4, when the lengths of the outflow pipes 42a and 42b from the branch point of the refrigerant pipe 30b are compared, the outflow pipe 42b is longer than the outflow pipe 42 a. In addition, when attention is paid to the potential energy of the refrigerant, the potential energy of the first accumulator 15a is higher than the potential energy of the second accumulator 15 b. It appears that the refrigerant of the first accumulator 15a flows out more easily than the refrigerant of the second accumulator 15 b. However, since the refrigerant flowing out of the outflow pipes 42a and 42b is gas, it is considered that the influence of pressure loss or the like does not become a problem as compared with the suction pipes 41a and 41 b.

Next, a configuration in which the accumulator 15 in embodiment 1 can distribute the refrigerant and the refrigerating machine oil more evenly to the two accumulators without being affected by the state of the refrigerant flowing in will be described.

Fig. 5A is a side view showing one configuration example of the accumulator shown in fig. 1. Fig. 5B is a top view of the accumulator shown in fig. 5A. Fig. 5C is a side view of the accumulator shown in fig. 5A, viewed from a different direction than fig. 5A. In fig. 5A to 5C, the outer shapes of the pipe provided inside the accumulator and the pipe provided behind the accumulator are shown by broken lines and are shown as perspective views.

As shown in fig. 5A and 5C, the second energy storage 15b and the first energy storage 15A are arranged in the vertical direction (Z-axis arrow direction) with respect to the ground. In fig. 5A to 5C, the flow of the refrigerant is indicated by arrows, but is indicated by arrows of patterns different from each other, in order to clarify the respective flows of the refrigerant passing through the first accumulator 15A and the refrigerant passing through the second accumulator 15 b. As shown in fig. 5A to 5C, the suction pipe 41a and the suction pipe 41b are connected to the refrigerant pipe 30b via the T-branch pipe 18. The outflow pipe 42a and the outflow pipe 42b are connected to the suction port of the compressor 11 via the T-shaped junction pipe 19 and the refrigerant pipe 30 b.

As shown in fig. 5B, the T-shaped branch pipe 18 includes a base portion 18c connected to the refrigerant pipe 30B, and branch portions 18a and 18B that branch off from the base portion 18c in two directions in a horizontal direction. The branch portions 18a, 18b extend from the base portion 18c in opposite directions to each other in the Y axis. The branch portion 18a is connected to the suction pipe 41a, and the branch portion 18b is connected to the suction pipe 41 b.

As described with reference to fig. 2 and 3, the refrigerant drawn from the accumulator 15 into the compressor 11 returns to the accumulator 15 with the refrigerant circuit 2 as one cycle. The refrigerant returned to the accumulator 15 is branched at the T-branch pipe 18 into the branch portion 18a and the branch portion 18b, and flows into the suction pipe 41a and the suction pipe 41b in a balanced manner. By providing the T-branch pipe 18 at a portion where the accumulator 15 is connected to the refrigerant pipe 30b, the refrigerant and the refrigerating machine oil are distributed uniformly to the second accumulator 15b and the first accumulator 15a without being affected by the state of the refrigerant.

Further, a T-junction pipe 19 is connected to the outflow pipe 42a of the first accumulator 15a and the outflow pipe 42b of the second accumulator 15 b. The T-junction pipe 19 has the same structure as the T-branch pipe 18. The T-junction pipe 19 is configured to join the outflow pipes 42a and 42b and connect the outflow pipes to the suction port of the compressor 11 via the refrigerant pipe 30 b. According to this configuration, the outflow pipes 42a and 42b do not need to extend to the compressor 11 and be connected to the compressor 11, respectively, and thus the increase in the manufacturing cost of the piping can be suppressed.

As shown in fig. 5A, the outflow pipe 42a is bent in a U shape inside the first accumulator 15A, and a nozzle 51a through which the refrigerant of the gas flows is directed upward. This is to prevent the liquid refrigerant stored in the first accumulator 15a from entering the outflow pipe 42 a. The outflow pipe 42b in the second accumulator 15b has the same structure as the outflow pipe 42a, and therefore, a detailed description thereof will be omitted.

As shown in fig. 5A to 5C, the first accumulator 15A and the second accumulator 15b are connected to each other by a pressure equalizer 17. According to this configuration, the difference in pressure loss due to the difference in the pipe length between the suction pipe 41a and the suction pipe 41b is reduced, and the pressure inside the first accumulator 15a and the second accumulator 15b is more equalized. The diameter of the pressure equalizer tube 17 is, for example, about 9.52 mm.

Next, the positions of the orifice 71a of the pressure equalizer 17 connected to the first accumulator 15a and the orifice 71b of the pressure equalizer 17 connected to the second accumulator 15b will be described. The first energy storage 15a and the second energy storage 15b have the same structure, and therefore the case of the first energy storage 15a will be described here.

As shown in fig. 5A, the nozzle 71a is located higher than the nozzle 51a of the outflow pipe 42 a. This is to prevent the liquid refrigerant stored in the first accumulator 15a from entering the pressure equalizing tube 17. In the second accumulator 15b, the positional relationship between the nozzle 51b and the nozzle 71b of the outflow tube 42b is the same as the positional relationship between the nozzle 51a and the nozzle 71a, and therefore, detailed description thereof is omitted.

Further, the nozzle 71a is preferably located at a position close to the nozzle 52a (see fig. 5A) of the suction pipe 41a in the first accumulator 15A and at a different height from the nozzle 52 a. In the configuration example shown in fig. 5A, the nozzle 71a is located higher than the nozzle 52 a. The reason why the nozzle 71a is preferably located at a different height from the nozzle 52a will be described with reference to fig. 5A and 6. Fig. 6 is a perspective view showing one configuration example of the suction pipe in the first accumulator shown in fig. 5B.

The nozzle 52a of the suction pipe 41a is formed by obliquely cutting a cylindrical pipe, and has an elliptical cross-sectional shape. This is to cause the refrigerant flowing into the first accumulator 15a to flow along the wall of the cylindrical container and generate a swirling flow. The arrows in fig. 6 indicate the direction of the swirling flow. The liquid refrigerant separates near the side walls of the container and the gaseous refrigerant separates near the center of the container according to the difference in density between the liquid and the gas of the refrigerant. The pressure near the side wall of the vessel is higher than the average pressure inside the vessel due to the swirling flow. Therefore, when the pressure equalizer 17 is attached to the side wall of the first accumulator 15a, the height of the position of the orifice 71a is made different from the height of the position of the orifice 52a as shown in fig. 5C. The positional relationship between nozzle 71b and nozzle 52b in second accumulator 15b is the same as the positional relationship between nozzle 71a and nozzle 52a, and therefore, the detailed description thereof will be omitted.

Further, as described above, since the pressure of the swirling flow rises near the side wall of the tank, the vicinity of the center of the tank approaches the average pressure inside the tank in the first accumulator 15 a. Therefore, it is preferable that the orifice 71a is located in the first accumulator 15a within a predetermined range from the center in the horizontal plane. This range can be determined by performing experiments in advance, measuring the pressure distribution from the center of the container to the side wall, and determining the pressure distribution based on the measurement result. When the nozzle 71a is located within a predetermined range from the center in the horizontal plane in the first energy storage 15a, the position of the nozzle 71a may be the same height as the position of the nozzle 52 a. In the second energy storage device 15b, the position of the horizontal plane of the nozzle 71b is also the same as that of the nozzle 71a in the first energy storage device 15a, and therefore, detailed description thereof is omitted.

Here, a modified example 1 of the structure of the pressure equalizer 17 in embodiment 1 will be described. Fig. 7 is a plan view showing a configuration of modification 1 of the accumulator shown in fig. 5A to 5C. Fig. 7 corresponds to a plan view when the first accumulator 15a in modification 1 is viewed from the same direction as fig. 5B.

In modification 1, the pressure equalizing pipe 17 is connected to the center of the upper surface of the tank of each of the first accumulator 15a and the second accumulator 15 b. As shown in fig. 7, the orifice 71a of the pressure equalizing pipe 17 is connected to the first accumulator 15a at the center of the upper surface of the first accumulator 15 a. Although not shown in the figure, the second accumulator 15b is connected to the center of the upper surface of the first accumulator 15a at the orifice 71a of the pressure equalizer 17.

In the structure of modification 1, of the orifices 71a, 71b of the pressure equalizer 17, the orifice 71a is centered on the level of the first accumulator 15a, and the orifice 71b is centered on the level of the second accumulator 15 b. Thus further suppressing the influence of the swirling flow.

Next, a modified example 2 of the structure of the pressure equalizer 17 in embodiment 1 will be described.

Fig. 8 is a side view showing the structure of modification 2 of the accumulator shown in fig. 5A to 5C. Fig. 8 corresponds to a side view when the first accumulator 15A and the second accumulator 15b in modification 2 are viewed from the same direction as fig. 5A.

As shown in fig. 8, the pressure equalizer 17 extends linearly from the second energy storage 15b to the first energy storage 15a in the vertical direction (Z-axis arrow direction). The pressure equalizing pipe 17 penetrates the wall of the upper surface of the second accumulator 15b at the opening 81b and penetrates the wall of the lower surface of the first accumulator 15a at the opening 81 a. The opening 81a is centrally located in the horizontal plane of the first energy reservoir 15a and the opening 81b is centrally located in the horizontal plane of the second energy reservoir 15 b. The pressure equalizing pipe 17 is welded to the wall of the upper surface of the second energy storage 15b at the opening 81b and to the wall of the lower surface of the first energy storage 15a at the opening 81 a. In modification 2, as in fig. 5A, nozzle 71a is located at a higher position than nozzles 51a and 52a, and nozzle 71b is located at a higher position than nozzles 51b and 52 b.

In the structure of modification 2, the first accumulator 15a is supported by the second accumulator 15b via the pressure equalizer 17, thereby improving the stability of the accumulator 15. Further, since the pressure equalizer 17 extends from the second accumulator 15b to the first accumulator 15a in a straight line, the pipe does not need to be bent. The number of the connection points between the pressure equalizer 17 and the first accumulator 15A and the second accumulator 15b is the same as that described with reference to fig. 5A to 5C. Thus, an increase in welding work can be prevented.

In embodiment 1, the case where two accumulators are used has been described, but three or more accumulators may be used. The case where three accumulators are provided will be described.

Fig. 9 is a side view showing an arrangement example in the case where three accumulators are provided in the accumulator shown in fig. 5C. In fig. 9, the suction pipe and the outflow pipe are omitted from the drawing. As shown in fig. 9, a third energy storage 15C is provided in addition to the first energy storage 15A and the second energy storage 15b shown in fig. 5A to 5C. The third energy storage device 15c is provided as the lowermost layer on the floor of the outdoor unit 10, and two energy storage devices are provided above the third energy storage device 15c in this order from the second energy storage device 15b to the first energy storage device 15 a. As shown in fig. 9, the pressure equalizing pipe 17 is connected to the side wall of the third energy storage 15c, similarly to the first energy storage 15a and the second energy storage 15 b. Even when there are three accumulators, the pressure inside the three accumulators can be equalized by providing the pressure equalizing pipe 17.

In addition, when four accumulators are provided, the refrigerant flowing in from the flow path switching valve 13 can be distributed to the four accumulators in a balanced manner by combining the three T-branch pipes 18 with the four accumulators. This will be specifically described. Of the three T-branch pipes 18, the base portions 18c of the other two T-branch pipes 18 are connected to the two branch portions 18a, 18b of one T-branch pipe 18, respectively. The suction pipes of the two accumulators are connected to the branch portions 18a and 18b of the respective T-branch pipes 18 for the other two T-branch pipes 18. According to this configuration, the refrigerant flowing from the flow path switching valve 13 is bisected by the first T-branch pipe 18, and the bisected refrigerant is further bisected by the remaining two T-branch pipes 18. As a result, the refrigerant flowing from the flow path switching valve 13 is equally divided into four parts, and the refrigerant can be equally distributed to the four accumulators.

In embodiment 1, if the number of accumulators to be provided is even, refrigerant can be distributed evenly to the plurality of accumulators by combining three or more T-branch pipes 18. In this case, three or more T-shaped confluence pipes 19 may be combined with the pipe on the side from which the refrigerant flows out of the accumulator 15.

The air conditioner 1 according to embodiment 1 includes: a refrigerant circuit 2 including a compressor 11; and a plurality of accumulators connected in parallel to a suction port of the compressor 11 in the refrigerant circuit 2, the plurality of accumulators being disposed in a vertical direction with respect to the ground.

In embodiment 1, since the plurality of accumulators are provided in the vertical direction, the volume of the refrigerant to be stored increases, and an increase in the installation area of the accumulators in the outdoor unit 10 can be suppressed.

In addition, in embodiment 1, a large volume can be secured even if the volume of 1 accumulator is reduced by using a plurality of accumulators in combination. Therefore, the energy storage device can be manufactured at low cost without manufacturing a large-volume energy storage device which is technically difficult and requires high withstand voltage. The unit price of the energy accumulator can be reduced by mass production of the energy accumulators with the same specification. In addition, when the amount of refrigerant required for each air conditioner is different, the number of combined accumulators may be changed according to the required capacity.

As described in embodiment 1, the configuration may be such that: the air conditioning system 1 has a pressure equalizing pipe 17 that connects the interiors of the plurality of energy storages to one another. In this case, the difference in pressure loss due to the difference in the pipe length of the suction pipes 41a and 41b of the plurality of accumulators is reduced, and the internal pressure between the plurality of accumulators becomes more balanced.

As described in embodiment 1, the configuration may be such that: in each of the plurality of accumulators, the orifices 71a, 71b of the pressure equalizing tube 17 are located at a higher position than the orifices 51a, 51b of the outflow tubes 42a, 42 b. In this case, the liquid refrigerant is prevented from entering the pressure equalizing tube 17, and the pressure equalizing tube 17 can play a role of equalizing the internal pressure among the plurality of accumulators.

As described in embodiment 1, the configuration may be such that: in each of the plurality of accumulators, the height of the orifice 71a, 71b of the pressure equalizing pipe 17 is different from the height of the orifice 52a, 52b of the suction pipe 41a, 41 b. In this case, since the influence of the swirling flow near the orifices 71a, 71b of the pressure equalizer 17 is small, the internal pressure equalization between the accumulators is improved.

As described in embodiment 1, the configuration may be such that: in each of the plurality of accumulators, the orifices 71a, 71b of the pressure equalizing pipe 17 are located within a predetermined range from the center of the accumulator in a horizontal plane. In this case, the influence of the swirling flow is further suppressed, and the balance of the internal pressure among the plurality of accumulators can be improved.

As described in embodiment 1, the configuration may be such that: the pressure equalizer 17 extends from the second energy storage 15b to the first energy storage 15a linearly in the vertical direction. In this case, the first energy storage device 15a is supported by the second energy storage device 15b via the pressure equalizing pipe 17, and the stability of the energy storage device 15 is improved.

As described in embodiment 1, the configuration may be such that: the refrigerant circuit 2 includes a T-branch pipe 18, the T-branch pipe 18 includes two branch portions 18a and 18b that branch horizontally in two directions, and the two branch portions 18a and 18b are connected to two suction pipes 41a and 41b, and branch the refrigerant flowing from the refrigerant circuit 2 to the first accumulator 15a and the second accumulator 15 b. In this case, the refrigerant and the refrigerating machine oil are distributed evenly to the second accumulator 15b and the first accumulator 15a without being affected by the state of the refrigerant.

As described in embodiment 1, the configuration may be such that: the air conditioner 1 includes a T-junction pipe 19, and the T-junction pipe 19 joins two outflow pipes 42a and 42b and is connected to a suction port of the compressor 11 via a refrigerant pipe 30 b. In this case, the outflow pipes 42a and 42b do not need to be extended to the compressor 11, and thus the increase in the manufacturing cost of the pipes can be suppressed.

In embodiment 1, the case where the pressure equalizer 17 is used as means for equalizing the pressure in the plurality of accumulators has been described, but the present invention is not limited to the case where the pressure equalizer 17 is used. For example, bernoulli's law may be applied to the suction pipes 41a and 41b of the accumulator 15 described with reference to fig. 5A to 5C. Bernoulli's law refers to a pressure drop if the velocity of a fluid increases. It is conceivable to design the thicknesses of the suction pipe 41a and the suction pipe 41b based on this law so that the difference in pressure loss due to the length of the piping is reduced. In this case, the T-branch pipe 18 may not be used on the refrigerant suction side of the accumulator 15.

In the accumulator 15 described with reference to fig. 5A to 5C, instead of providing the pressure equalizing pipe 17, a throttle device may be provided in the suction pipe 41 a. Fig. 10 is a refrigerant circuit diagram showing another configuration example of the air conditioner according to embodiment 1 of the present invention. In the air conditioner 1a shown in fig. 10, a throttle device 60 is provided in the suction pipe 41 a. The throttle device 60 adjusts the throttle amount so that the difference between the pressures of the first accumulator 15a and the second accumulator 15b becomes small. For example, it is conceivable that pressure sensors, not shown, are provided in the first accumulator 15a and the second accumulator 15b, respectively, and the control unit 35 adjusts the throttle amount of the throttle device 60 based on the measurement values of these pressure sensors.

In embodiment 1, the description has been given of the case where the volumes of the plurality of accumulators are the same, but the volumes of the plurality of accumulators may be different from each other. The case where the volumes of the plurality of accumulators are different will be described with reference to the accumulator 15 described with reference to fig. 4. The energy accumulator 15 shown in fig. 4 is not provided with a T-branch 18 and a pressure equalizer 17.

It is considered that the amounts of refrigerant distributed to the two accumulators are greatly affected by the difference in pressure loss due to the difference in the pipe lengths of the suction pipes 41a and 41 b. As explained with reference to fig. 4, there is a tendency for the amount of refrigerant allocated to the first accumulator 15a to be greater than the amount of refrigerant allocated to the second accumulator 15 b. In this case, the volume of the first energy storage device 15a may be made larger than the volume of the second energy storage device 15 b. But the area of the first energy storage 15a is made smaller than twice the area of the second energy storage 15 b.

On the other hand, it is considered that the amount of refrigerant distributed to the two accumulators is greatly affected by the ratio of liquid in the refrigerant, compared to the difference in pressure loss due to the difference in pipe length. For example, the air conditioning apparatus 1 mainly performs an operation for increasing the ratio of the refrigerant liquid flowing into the accumulator 15. As explained with reference to fig. 4, there is a tendency for the amount of refrigerant allocated to the second accumulator 15b to be greater than the amount of refrigerant allocated to the first accumulator 15 a. In this case, the volume of the second energy storage device 15b may be made larger than the volume of the first energy storage device 15 a. But the second energy storage 15b is provided in an area smaller than twice the area of the first energy storage 15 a.

Thus, even if the volumes of the plurality of accumulators are different, the installation area of the accumulator on the ground can be made smaller than the area obtained by doubling the installation area of one accumulator having a smaller volume. In addition, since the second energy storage 15b is disposed below the first energy storage 15a, if the volume of the second energy storage 15b is larger than that of the first energy storage 15a, the stability of the energy storage 15 is improved.

Description of reference numerals: 1. 1a … air conditioning unit; 2 … refrigerant circuit; 10 … outdoor unit; 11 … compressor; 12 … oil separator; 13 … flow path switching valve; 14 … heat source side heat exchanger; 15 … an energy storage device; 15a … first energy store; 15b … second energy store; 15c … third energy store; 16 … oil return capillary; 17 … pressure equalizing tube; 18 … T branch pipe; 18a, 18b … branch portions; 18c … base; 19 … T-shaped confluence pipe; 20a to 20d … indoor units; 21 a-21 d … throttle devices; 22a to 22d … load side heat exchangers; 30a, 30b … refrigerant pipes; 35 … control unit; 41a, 41b … suction tube; 42a, 42b … outflow tube; 51a, 51b, 52a, 52b … spout; 60 … throttle device; 71a, 71b … orifice; 81a, 81b … are open.

Claims (10)

1. An air conditioning apparatus, comprising:

a refrigerant circuit including a compressor; and

two accumulators connected in parallel to a suction port of the compressor in the refrigerant circuit,

the two accumulators are provided in a vertical direction with respect to the ground such that one accumulator of the two accumulators is located above the other accumulator.

2. The air conditioner according to claim 1,

there is also a pressure equalizing tube connecting the interiors of the two energy stores to one another.

3. Air conditioning unit according to claim 2,

in each of the two accumulators, an orifice of the pressure equalizing pipe in the accumulator is located at a position higher than an orifice of an outflow pipe in the accumulator through which the refrigerant flows out from the accumulator to the compressor.

4. Air conditioning unit according to claim 3,

the height of the orifice of the pressure equalizer in the accumulator in the vertical direction is different from the height of the orifice of the suction pipe in the accumulator through which the refrigerant flows from the refrigerant circuit to the accumulator in the vertical direction.

5. Air conditioning unit according to claim 3 or 4,

the pipe orifice of the pressure equalizing pipe in the energy accumulator is positioned in a preset range away from the center of the energy accumulator in the horizontal plane.

6. Air conditioning unit according to claim 5,

the pressure equalizer is configured to extend linearly from one accumulator to the other accumulator in the vertical direction of the two accumulators.

7. An air conditioning apparatus according to any one of claims 1 to 4,

further comprises a T-branch pipe connected to the refrigerant circuit and having two branch portions branched horizontally in two directions,

the two branch portions are connected to two suction pipes through which the refrigerant flows into the two accumulators, and branch the refrigerant flowing from the refrigerant circuit to the two accumulators.

8. Air conditioning unit according to claim 5,

further comprises a T-branch pipe connected to the refrigerant circuit and having two branch portions branched horizontally in two directions,

the two branch portions are connected to two suction pipes through which the refrigerant flows into the two accumulators, and branch the refrigerant flowing from the refrigerant circuit to the two accumulators.

9. Air conditioning unit according to claim 6,

the compressor further includes a T-junction pipe that joins two outflow pipes through which the refrigerant flows out of the two accumulators, and is connected to a suction port of the compressor via one refrigerant pipe.

10. An air conditioning apparatus according to any one of claims 1 to 4,

the two accumulators have different volumes of stored refrigerant from each other.

Images