CN113834144A

CN113834144A - Air conditioning system

Info

Publication number: CN113834144A
Application number: CN202010586016.0A
Authority: CN
Inventors: 张利; 王瑞雄
Original assignee: Shanghai Highly Electrical Appliances Co Ltd
Current assignee: Shanghai Highly Electrical Appliances Co Ltd
Priority date: 2020-06-24
Filing date: 2020-06-24
Publication date: 2021-12-24
Anticipated expiration: 2040-06-24
Also published as: CN113834144B

Abstract

The invention provides an air conditioning system, which comprises a compressor, wherein a shell is provided with a first air inlet hole, a second air inlet hole, an exhaust hole and a first exhaust hole, the first air inlet hole, a first air cylinder and the first exhaust hole are communicated, and the second air inlet hole, the second air cylinder and the exhaust hole are communicated; the first port of the medium-pressure storage tank is communicated with the exhaust hole; a first port of the first four-way valve is communicated with the air inlet of the first liquid storage device, a second port of the first four-way valve is communicated with the air inlet of the second liquid storage device, a third port of the first four-way valve is communicated with the first air suction port, and a fourth port of the first four-way valve is communicated with the second air suction port; the first port of the second four-way valve is communicated with the first air inlet, the second port of the second four-way valve is communicated with the air outlet of the first liquid storage device, the third port of the second four-way valve is communicated with the second port of the medium-pressure storage tank, and the fourth port of the second four-way valve is communicated with the second air outlet; this application makes air conditioning system can adapt to different operating mode demands, has improved the efficiency of compressor.

Description

Air conditioning system

Technical Field

The invention relates to the field of refrigeration equipment, in particular to an air conditioning system.

Background

In the conventional double-suction double-row compressor, in order to realize a good heating effect under the condition of low-temperature heating, the pressure ratio of the compressor needs to be improved as much as possible. However, this has two undesirable effects: first, the efficiency of the compressor is reduced when the pressure ratio is high; secondly, when the pressure ratio is higher, the exhaust temperature is also higher, and the heat dissipation of the motor in the compressor is influenced, so that the service life of the motor is influenced, and even the motor can be burnt.

In the existing two-stage compression type compressor, the pressure ratio in the two-stage compression process is relatively small under the condition of low-load operation. For this type of rolling rotor compressor, the back pressure of the vanes will be very small when the pressure ratio is very small, and the vanes may be separated from the piston surface during operation, causing the compressor to idle.

Therefore, the existing double-suction double-row compressor is not suitable for severe working conditions such as low-temperature heating and the like although being suitable for low-load working conditions; the existing two-stage compression type compressor is suitable for severe working conditions but not suitable for low-load working conditions. The two compressors cannot adapt to different working condition requirements.

Disclosure of Invention

In view of this, the present invention provides an air conditioning system, which is adapted to the use requirements under different working conditions, and improves the energy efficiency and performance of the compressor.

According to an aspect of the present invention, there is provided an air conditioning system including:

the compressor comprises a shell, a first liquid storage device, a second liquid storage device, a first air cylinder and a second air cylinder, wherein the first air cylinder and the second air cylinder are arranged in the shell;

the first port of the medium-pressure storage tank is communicated with the exhaust hole, and the medium-pressure storage tank is used for storing the entering gas and cooling the entering gas so as to enable the temperature of the discharged gas to be lower than that of the entering gas;

a first port of the first four-way valve is communicated with an air inlet of the first liquid storage device, a second port of the first four-way valve is communicated with an air inlet of the second liquid storage device, a third port of the first four-way valve is communicated with the first air suction port, and a fourth port of the first four-way valve is communicated with the second air suction port; and

a first port of the second four-way valve is communicated with the first air inlet, a second port of the second four-way valve is communicated with an air outlet of the first liquid storage device, a third port of the second four-way valve is communicated with a second port of the medium-pressure storage tank, and a fourth port of the second four-way valve is communicated with a second air outlet;

the air conditioning system has at least two working states, and under the working state of parallel connection of the double cylinders, a first port and a third port of the first four-way valve are communicated, and a second port and a fourth port are communicated; a first port of the second four-way valve is communicated with a second port, and a third port of the second four-way valve is communicated with a fourth port; under the working state of the two cylinders connected in series, the second port and the third port of the first four-way valve are communicated, and the first port and the fourth port are communicated; and a first port and a third port of the second four-way valve are communicated, and a second port and a fourth port are communicated.

Preferably, the air conditioning system further comprises an enthalpy-increasing control valve, the third port of the medium-pressure storage tank is connected with an external air supply source through an air supply pipeline, and the enthalpy-increasing control valve is arranged in the air supply pipeline and controls the air supply pipeline to be switched on or switched off.

Preferably, in a parallel operation state of the two cylinders, the gas sucked by the first air intake enters the first cylinder of the compressor through the first reservoir and the first air intake in sequence, is compressed, and is discharged from the first exhaust port; and the gas sucked by the second air suction port enters a second cylinder of the compressor through the second liquid storage device and a second air inlet hole in sequence to be compressed, is output to the medium-pressure storage tank from the air exhaust hole and is exhausted through the second air exhaust hole.

Preferably, in a working state of two cylinders connected in series, the gas sucked by the first air intake enters the second cylinder of the compressor through the second reservoir and the second air intake for first-stage compression, and after being output to the medium-pressure reservoir from the air outlet, the gas enters the first cylinder of the compressor again through the first air intake for second-stage compression, and is discharged from the first air outlet; the gas sucked through the second suction port is discharged from the second discharge port via the first reservoir.

Preferably, the air conditioning system further includes a one-way valve located between the second exhaust port and the fourth port of the second four-way valve, the one-way valve having a state of being turned on in a direction directed to the second exhaust port by the second four-way valve and being turned off in a reverse direction.

Preferably, the air conditioning system further has a two-stage compression zone injection working state, and in the two-stage compression zone injection working state, the enthalpy-increasing control valve controls the conduction of the air supply pipeline, so that the external air supply source flows to the medium-pressure storage tank for supplying air, and the temperature of the external air supply source is lower than that of the gas discharged from the exhaust hole, so as to reduce the temperature of the gas in the medium-pressure storage tank.

Preferably, when the external environment temperature is lower than a second preset threshold or higher than a third preset threshold, the air conditioning system is in the double-cylinder series working state, and the second preset threshold is smaller than the third preset threshold.

Preferably, when the external environment temperature is lower than a fourth preset threshold or higher than a fifth preset threshold, the air conditioning system is in the two-stage compression band spraying working state, the fourth preset threshold is smaller than the fifth preset threshold, the fourth preset threshold is smaller than the second preset threshold, and the fifth preset threshold is larger than the third preset threshold.

Preferably, the air conditioning system further includes a first evaporator, a second evaporator, a first condenser, a second condenser, a first throttle valve and a second throttle valve, the first throttle valve is disposed between the first evaporator and the first condenser, the first evaporator is further connected to the first air intake, and the first condenser is further connected to the first exhaust port;

the second throttle valve is arranged between the second evaporator and the second condenser, the second evaporator is further connected with the second air suction port, and the second condenser is further connected with the second air exhaust port.

Compared with the prior art, the invention has the beneficial effects that:

the air conditioning system provided by the invention solves the problems that the service life of a motor is influenced by higher exhaust temperature and the efficiency of the compressor is influenced by high pressure ratio of the existing double-suction double-row type compressor, and the back pressure of the existing two-stage compression type compressor is small under a low-load working condition, so that blades are separated from a piston, and the air conditioning system can be switched among three operation modes in one air conditioning system, thereby adapting to different working condition requirements and improving the performance and the energy efficiency of the compressor in the air conditioning system.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

FIG. 1 is a schematic view of a pipeline communication structure of an air conditioning system in a double-cylinder parallel working state according to an embodiment of the present invention;

fig. 2 is a schematic view of a pipeline communication structure of an air conditioning system in a double-cylinder series working state according to an embodiment of the present invention.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the subject matter of the present disclosure can be practiced without one or more of the specific details, or with other methods, materials, devices, etc. In other instances, well-known technical solutions have not been shown or described in detail to avoid obscuring aspects of the present disclosure. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements/components/parts/etc.; the terms "comprising," "having," and "providing" are intended to be inclusive and mean that there may be additional elements/components/etc. other than the listed elements/components/etc.

As shown in fig. 1 and 2, an embodiment of the present invention discloses an air conditioning system. The air conditioning system comprises a compressor 11, a medium-pressure storage tank 12, a first four-way valve 13, a second four-way valve 14 and an enthalpy-increasing control valve 15.

The compressor 11 includes a housing 21, a first accumulator 22, a second accumulator 23, a first cylinder 24, and a second cylinder 25. The first cylinder 24 and the second cylinder 25 are provided in the housing 21. The housing 21 is provided with a first intake hole 31, a second intake hole 32, an exhaust hole 33, and a first exhaust port 34. The first intake port 31, the first cylinder 24, and the first exhaust port 34 communicate with each other, and the second intake port 32, the second cylinder 25, and the exhaust port 33 communicate with each other.

The first port of the medium-pressure tank 12 communicates with the exhaust hole 33. The medium pressure storage tank 12 is used to store the incoming gas and cool the incoming gas so that the temperature of the outgoing gas is less than the temperature of the incoming gas.

The first port 131 of the first four-way valve 13 is connected to the air inlet of the first accumulator 22, the second port 132 of the first four-way valve 13 is connected to the air inlet of the second accumulator 23, the third port 133 of the first four-way valve 13 is connected to the first air inlet 35, and the fourth port 134 of the first four-way valve 13 is connected to the second air inlet 36.

The first port 141 of the second four-way valve 14 is communicated with the first air inlet hole 31, the second port 142 of the second four-way valve 14 is communicated with the air outlet of the first reservoir 22, the third port 143 of the second four-way valve 14 is communicated with the second port of the medium pressure storage tank 12, and the fourth port 144 of the second four-way valve 14 is communicated with the second air outlet 37.

And a third port of the medium-pressure storage tank 12 is connected with an external air supply source through an air supply pipeline, and the enthalpy-increasing control valve 15 controls the on and off of the air supply pipeline.

In this embodiment, the air conditioning system further includes a first evaporator, a second evaporator, a first condenser, a second condenser, a first throttle valve, and a second throttle valve (not shown), the first throttle valve is disposed between the first evaporator and the first condenser, the first evaporator is further connected to the first air intake port 35, and the first condenser is further connected to the first exhaust port 34. The first evaporator, the first condenser, the first throttle valve and the piping between the first intake port 35 and the first exhaust port 34 constitute a first air conditioning subsystem.

The second throttle valve is provided between the second evaporator and the second condenser, the second evaporator is further connected to the second air intake port 36, and the second condenser is further connected to the second air exhaust port 37. The second evaporator, the second condenser, the second throttle valve and the piping between the second suction port 36 and the second discharge port 37 constitute a second air conditioning subsystem. The first air conditioning subsystem and the second air conditioning subsystem constitute the air conditioning system described above in this application.

In this embodiment, the air conditioning system has three operating states, which are a two-cylinder parallel operating state, a two-cylinder series operating state, and a two-stage compression band injection operating state. When the air conditioning system is in a double-cylinder parallel working state, the refrigerant can be simultaneously provided for the first air conditioning subsystem and the second air conditioning subsystem. When the air conditioning system is in a double-cylinder series working state and a two-stage compression band injection working state, only one air conditioning subsystem can provide the refrigerant.

The two-cylinder parallel operation mode is a double suction and double row operation mode, and in the two-cylinder parallel operation mode, the first port 131 of the first four-way valve 13 is connected to the third port 133 of the first four-way valve 13, and the second port 132 of the first four-way valve 13 is connected to the fourth port 134 of the first four-way valve 13. The first port 141 of the second four-way valve 14 is in communication with the second port 142 of the second four-way valve 14, and the third port 143 of the second four-way valve 14 is in communication with the fourth port 144 of the second four-way valve 14.

In the parallel operation of the two cylinders, the gas sucked through the first suction port 35 sequentially flows into the first cylinder 24 of the compressor 11 through the first accumulator 22 and the first suction port 31, is compressed, and is discharged through the first discharge port 34. The gas sucked through the second suction port 36 sequentially enters the second cylinder 25 of the compressor 11 through the second accumulator 23 and the second suction port 32, is compressed, is discharged from the discharge port 33 to the intermediate pressure tank 12, and is discharged through the second discharge port 37.

Wherein, the parallel working state of the double cylinders is suitable for running under the condition of low load. Therefore, the problem that the pressure ratio is too low when the two-stage compression compressor 11 is used under the condition of low load can be solved. The compressor 11 is switched from a double-cylinder series working state to a double-cylinder parallel working state, and meanwhile, the refrigerant is supplied to the first air-conditioning subsystem and the second air-conditioning subsystem, so that the pressure ratio of the two cylinders in the compressor 11 is improved, and the problem of low back pressure of the compressor is solved.

The two-cylinder series operating state is a two-stage compression operating mode, and in the two-cylinder series operating state, the second port 132 of the first four-way valve 13 is connected to the third port 133 of the first four-way valve 13, and the first port 131 of the first four-way valve 13 is connected to the fourth port 134 of the first four-way valve 13. The first port 141 of the second four-way valve 14 is in communication with the third port 143 of the second four-way valve 14, and the second port 142 of the second four-way valve 14 is in communication with the fourth port 144 of the second four-way valve 14.

In the two-cylinder tandem operation, the gas sucked through the first suction port 35 is introduced into the second cylinder 25 of the compressor 11 through the second accumulator 23 and the second suction port 32, is compressed in the first stage, is discharged from the discharge port 33 to the intermediate pressure storage tank 12, is introduced into the first cylinder 24 of the compressor 11 again through the first suction port 31, is compressed in the second stage, and is discharged from the first discharge port 34. The gas sucked through the second inlet port 36 is discharged from the second outlet port 37 through the first reservoir 22. The second air conditioning subsystem is deactivated and two stages of compression are achieved by the air drawn through the first air intake port 35.

The double-cylinder series working state is suitable for operation under the conditions of low-temperature heating or high-temperature refrigeration. In this case, the motor may be burnt out in order to improve the energy efficiency of the compressor and prevent the pressure ratio of the compressor from being excessively high. One subsystem in the air conditioning system is closed, only the refrigerant is supplied to the other air conditioning subsystem with higher priority, the parallel working state of the double cylinders of the compressor 11 is switched into the serial working state of the double cylinders, and the large pressure ratio is divided into two smaller pressure ratios through two-stage compression. The gas discharged from the gas discharge hole 33 after the first stage compression is discharged into the medium-pressure tank 12, and pressure pulsation at the time of gas discharge can be reduced. And the medium-pressure storage tank 12 has a certain heat exchange effect, the temperature of the first-stage exhaust gas can be reduced, the mass flow of the refrigerant during the second-stage suction can be improved, and the volumetric efficiency is improved. By switching the double-suction double-row mode of the compressor 11 into the two-stage compression working mode under the severe working condition, the problem that the service life of the motor of the compressor 11 is shortened under the severe working condition is solved.

It should be noted that, in the present embodiment, in the working state of the two cylinders connected in series, the first air conditioning subsystem performs two times of compression, and the second air conditioning subsystem fails as an example. In other embodiments, the first air conditioning subsystem may be disabled and the second air conditioning subsystem may be subjected to two stages of compression.

When low-temperature heating or high-temperature refrigeration is carried out under worse working conditions, the air conditioning system under the working state of the double-cylinder series connection still cannot meet the use requirement. At this time, the compressor 11 is turned on in the two-stage compression band injection operation state. The two-stage compression zone injection working state is that the enthalpy-increasing control valve 15 is opened, namely the air supplement pipeline is opened on the basis of the working state of the double-cylinder series connection. Specifically, in the two-stage compression zone injection operating state, the enthalpy-increasing control valve 15 controls the conduction of the air supply pipe, so that the external air supply source flows to the medium-pressure storage tank 12 for air supply, and the temperature of the external air supply source is lower than the temperature of the gas discharged from the exhaust hole 33, so as to further reduce the air suction temperature of the second-stage compressor 11, increase the air suction flow of the second-stage compressor 11, and improve the performance of the compressor 11.

For example, in this embodiment, when the dual-cylinder parallel operating state is turned on, the corresponding low-load operating condition is that the difference between the set temperature of the air conditioner (i.e., the temperature set by the user) and the external environment temperature is smaller than a first preset threshold, where the first preset threshold may be 4 ℃, for example, in spring and autumn, the load of the compressor when the air conditioner is in use is generally low.

When the double-cylinder series working state is started, the corresponding severe working condition is that the external environment temperature is lower than a second preset threshold or higher than a third preset threshold, and the second preset threshold is smaller than the third preset threshold.

When the two-stage compression zone injection working state is started, the corresponding worse working condition is that the external environment temperature is lower than a fourth preset threshold or higher than a fifth preset threshold. The fourth preset threshold is smaller than the fifth preset threshold, the fourth preset threshold is smaller than the second preset threshold, and the fifth preset threshold is larger than the third preset threshold.

For example, the second preset threshold may be 2 ℃, the third preset threshold may be 33 ℃, the fourth preset threshold may be-3 ℃, and the fifth preset threshold may be 38 ℃. But the application is not so limited.

It should be noted that the above examples for the low load condition, the severe condition and the worse condition are only for helping understanding the present invention, and should not be regarded as a specific limitation to the present invention.

According to the embodiment, the air conditioning system can use the double-cylinder parallel working state under the low-load working condition, can use the double-cylinder serial working state under the severe working condition, and can use the two-stage compression belt injection working state under the severe working condition, so that the air conditioning system adapts to the use requirements of different working conditions, and the performance and the energy efficiency of the compressor are improved.

The working process of the air conditioning system of the embodiment may be the following steps: in the working state of parallel connection of the two cylinders, the low-temperature low-pressure gaseous refrigerant is compressed by the first cylinder 24 of the compressor 11 and then becomes a high-temperature high-pressure refrigerant, and then enters the first condenser to release heat, the liquid refrigerant after heat release is throttled by the first throttle valve and then becomes a low-temperature low-pressure gas-liquid two-phase mixture, and then enters the first evaporator to evaporate and absorb heat, and the liquid refrigerant after heat absorption becomes a low-temperature low-pressure gaseous refrigerant and then enters the first cylinder 24 of the compressor 11.

The low-temperature low-pressure gas refrigerant is compressed by the second cylinder 25 of the compressor 11 and then becomes a high-temperature high-pressure refrigerant, then enters the second condenser for heat release, the liquid refrigerant after heat release is throttled by the second throttle valve and then becomes a low-temperature low-pressure gas-liquid two-phase mixture, then enters the second evaporator for evaporation and heat absorption, and then becomes a low-temperature low-pressure gas refrigerant after heat absorption, and then enters the second cylinder 25 of the compressor 11. The above steps are repeated to form a complete refrigeration cycle. Therefore, the effect that one compressor corresponds to two sets of air conditioning systems is achieved.

In a preferred embodiment of the present invention, the air conditioning system further comprises a check valve 16, and the check valve 16 is located between the second exhaust port 37 and the fourth port 144 of the second four-way valve 14. The check valve 16 is in a state of being turned on in a direction from the second four-way valve 14 to the second exhaust port 37 and being turned off in the opposite direction. The one-way valve 16 prevents the refrigerant from flowing back from the condenser to the second four-way valve 14.

In summary, the air conditioning system disclosed by the invention at least has the following advantages:

the air conditioning system disclosed by the embodiment solves the problems that the service life of a motor is influenced by higher exhaust temperature and the efficiency of the compressor is influenced by high pressure ratio of the existing double-suction double-row type compressor, and the backpressure of the existing two-stage compression type compressor is small under a low-load working condition, so that blades are separated from a piston, and the switching among three operation modes in one air conditioning system is realized, thereby adapting to different working condition requirements, and improving the performance and the energy efficiency of the compressor in the air conditioning system.

In the description of the present invention, it is to be understood that the terms "bottom", "longitudinal", "lateral", "upper", "lower", "front", "rear", "vertical", "horizontal", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, are used only for convenience in describing the present invention and for simplification of description, and do not indicate or imply that the structures or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, are not to be construed as limiting the present invention. Furthermore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more and "several" means one or more unless otherwise specified.

In the description herein, references to the description of "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," etc., indicate that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. An air conditioning system, characterized in that the air conditioning system comprises:

2. The air conditioning system as claimed in claim 1, further comprising an enthalpy-increasing control valve, wherein the third port of the medium-pressure storage tank is connected to an external make-up air source through an air supplement pipeline, and the enthalpy-increasing control valve is disposed in the air supplement pipeline and controls the air supplement pipeline to be turned on or off.

3. The air conditioning system as claimed in claim 1, wherein in the parallel operation of the two cylinders, the gas sucked from the first suction port sequentially enters the first cylinder of the compressor through the first accumulator and the first suction port to be compressed, and is discharged from the first discharge port; and the gas sucked by the second air suction port enters a second cylinder of the compressor through the second liquid storage device and a second air inlet hole in sequence to be compressed, is output to the medium-pressure storage tank from the air exhaust hole and is exhausted through the second air exhaust hole.

4. The air conditioning system as claimed in claim 1, wherein in the two-cylinder series operation, the gas sucked from the first suction port enters the second cylinder of the compressor through the second accumulator and the second suction port to perform the first stage compression, and after being output from the discharge port to the medium pressure storage tank, the gas reenters the first cylinder of the compressor through the first suction port to perform the second stage compression, and is discharged from the first discharge port; the gas sucked through the second suction port is discharged from the second discharge port via the first reservoir.

5. The air conditioning system as claimed in claim 1, further comprising a check valve between the second exhaust port and the fourth port of the second four-way valve, the check valve having a state of being turned on in a direction directed to the second exhaust port by the second four-way valve and being turned off in a reverse direction.

6. The air conditioning system as claimed in claim 2, wherein the air conditioning system further has a two-stage compression band injection operating state, and in the two-stage compression band injection operating state, the enthalpy-increasing control valve controls the conduction of the air supply line, so that the external air supply source flows to the medium-pressure storage tank for air supply, and the temperature of the external air supply source is lower than that of the gas discharged from the exhaust hole, so as to lower the temperature of the gas in the medium-pressure storage tank.

7. The air conditioning system as claimed in claim 6, wherein when the external ambient temperature is lower than a second preset threshold or higher than a third preset threshold, the air conditioning system is in the dual-cylinder series operation state, and the second preset threshold is smaller than the third preset threshold.

8. The air conditioning system as claimed in claim 7, wherein when the external ambient temperature is lower than a fourth preset threshold or higher than a fifth preset threshold, the air conditioning system is in the two-stage compression band spraying operation state, the fourth preset threshold is smaller than the fifth preset threshold, the fourth preset threshold is smaller than the second preset threshold, and the fifth preset threshold is larger than the third preset threshold.

9. The air conditioning system as claimed in claim 1, further comprising a first evaporator, a second evaporator, a first condenser, a second condenser, a first throttle valve and a second throttle valve, the first throttle valve being provided between the first evaporator and the first condenser, the first evaporator being further connected to the first suction port, the first condenser being further connected to the first discharge port;