Multi-stage compressor and air conditioning unit

Abstract

The present disclosure provides a multi-stage compressor and an air conditioning unit, the multi-stage compressor including a flash tank, the flash tank being disposed within the multi-stage compressor, a refrigerant inlet of the flash tank being configured to communicate with a condenser, a vapor outlet of the flash tank being configured to communicate with a high-pressure stage suction inlet of the multi-stage compressor, and a liquid outlet of the flash tank being configured to communicate with an evaporator, the multi-stage compressor and the air conditioning unit of the present disclosure effectively improve the efficiency of the compressor.

Description

[Technical field]

[0001] This disclosure claims priority from Chinese Application No. 202111526275.5, filed on December 14, 2021, the contents of which are incorporated by reference in their entirety into this disclosure.

[0002] The present disclosure relates to the field of refrigeration technology, and in particular to multi-stage compressors and air conditioning units. [Background technology]

[0003] A multi-stage compressor (such as a screw compressor) is the main part of a commercial air conditioning unit and is called the "heart" of the commercial air conditioning device. At present, large commercial air conditioning units generally use a compressor and an external make-up air structure (such as an external plate heat exchanger) to adjust the compressor discharge temperature and improve the refrigeration capacity. However, such an external structure has complex pipelines and large pressure losses that affect the efficiency of the compressor. Summary of the Invention [Problem to be solved by the invention]

[0004] In the related art known to the inventor, the complicated pipelines and large pressure loss of the compressor's external supply structure reduce the compressor's efficiency. [Means for solving the problem]

[0005] A multi-stage compressor and air conditioning unit is provided in the embodiments of the present disclosure to solve the problem of low efficiency of compressors in the related art.

[0006] In order to achieve the above object, according to one aspect of the present disclosure, there is provided a multi-stage compressor including a flash tank, the flash tank being disposed within the multi-stage compressor, a refrigerant inlet of the flash tank being configured to communicate with a condenser, a vapor outlet of the flash tank being configured to communicate with a high-pressure stage suction inlet of the multi-stage compressor, and a liquid outlet of the flash tank being configured to communicate with an evaporator.

[0007] In some embodiments, the multi-stage compressor includes a housing formed with a flash chamber and a liquid storage area of ​​the flash tank, the liquid storage area being located below the flash chamber, the refrigerant inlet and liquid outlet both being located on the housing, and the vapor outlet and high pressure stage suction both being located within the housing.

[0008] In some embodiments, the multi-stage compressor further includes a high pressure stage structure and a low pressure stage structure disposed within the housing, and the flash tank is disposed between the high pressure stage structure and the low pressure stage structure.

[0009] In some embodiments, the high pressure stage structure and the low pressure stage structure are symmetrically arranged and connected by a coupler, the flash chamber is located at the coupler, and the liquid storage area is located below the coupler.

[0010] In some embodiments, the refrigerant inlet is in communication with the flash chamber and is disposed above the flash chamber, and the liquid outlet is in communication with the liquid storage area.

[0011] In some embodiments, a baffle plate is provided within the housing, the baffle plate being disposed between the coupler and the liquid storage area.

[0012] In some embodiments, a porous filter screen is provided within the housing, the porous filter screen being disposed between the connector and the liquid storage area.

[0013] In some embodiments, the flash tank includes a tank structure disposed within the multi-stage compressor, the tank structure forming a flash chamber and a liquid storage area of ​​the flash tank.

[0014] In some embodiments, the tank structure is disposed on the exhaust side of the multi-stage compressor.

[0015] In some embodiments, the multi-stage compressor further includes a high pressure stage arrangement and a low pressure stage arrangement disposed within the multi-stage compressor, the tank arrangement being disposed between the high pressure stage arrangement and the low pressure stage arrangement.

[0016] In some embodiments, the multi-stage compressor is a two-stage compressor.

[0017] According to another aspect of the present disclosure, there is provided an air conditioning unit including a multi-stage compressor as described above.

[0018] In some embodiments, the air conditioning unit further includes a condenser and an evaporator, the condenser in communication with the refrigerant inlet of the flash tank and the evaporator in communication with the liquid outlet of the flash tank.

[0019] The structure in which the flash tank is located in the compressor allows the enthalpy difference of the main loop refrigerant entering the evaporator to be enlarged, so that the refrigeration capacity of the compressor per unit mass of refrigerant is increased, and the efficiency of the compressor is further improved. Compared with the prior art compressor and external make-up air structure, the present disclosure allows the flash tank to be located in the compressor, and the external pipeline can be reduced or even omitted to reduce the pressure loss caused by the connection of the pipeline, and by reducing the pressure loss, the efficiency of the compressor can be effectively improved. Furthermore, the flash tank built into the compressor can make the entire air conditioning unit more compact and reduce the installation area. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a structural diagram of a multi-stage compressor according to Example I of the present disclosure. [Diagram 2] FIG. 2 is an internal structural diagram of a multi-stage compressor according to Example I of the present disclosure. [Diagram 3] FIG. 2 is an internal structural diagram of a multi-stage compressor according to Example II of the present disclosure. [Figure 4] FIG. 2 is a flow diagram of a refrigerant in a multi-stage compressor according to Example I of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Further detailed description of the present disclosure is provided below in conjunction with the accompanying drawings and specific examples, which do not limit the present disclosure.

[0022] 1 and 2, according to embodiment I of the present disclosure, a multi-stage compressor including a flash tank 10 is provided. The flash tank 10 is disposed in the multi-stage compressor (the dashed box in FIG. 1 is a structural part of the flash tank). A refrigerant inlet 101 of the flash tank 10 is configured to communicate with a condenser 21, a vapor outlet 102 of the flash tank 10 is configured to communicate with a high-pressure stage suction port of the multi-stage compressor, and a liquid outlet 103 of the flash tank 10 is configured to communicate with an evaporator 22.

[0023] In relation to the refrigerant flow diagram of Figure 4, the refrigerant from the condenser 21 enters the flash tank 10 at low pressure, where it rapidly evaporates to generate refrigerant vapor, and then enters the high-pressure stage inlet 35 of the multi-stage compressor through the vapor outlet 102 to undergo two-stage compression. Another portion of the refrigerant cools to form saturated liquid refrigerant, passes through the liquid outlet to the evaporator 22 in the main loop, enters the evaporator 22 for heat transfer and evaporation, and is sucked into the compressor, thereby completing the full cycle. The structure in which the flash tank 10 is located within the compressor allows for a larger enthalpy difference of the main loop refrigerant entering the evaporator, which increases the refrigeration capacity of the compressor per unit mass of refrigerant, and further improves the efficiency of the compressor.

[0024] Compared with the compressor and external make-up air structure of the related art, the present disclosure allows the flash tank 10 to be arranged inside the compressor, so as to reduce the pressure loss caused by the connection of the pipeline, the external pipeline can be reduced or even omitted, and the efficiency of the compressor can be effectively improved by reducing the pressure loss. Moreover, the flash tank arranged inside the compressor can make the whole air conditioning unit more compact and reduce the installation area.

[0025] 2, the multi-stage compressor includes a housing 31. The housing 31 is formed with the flash chamber 11 and the liquid storage area 12 of the flash tank 10. The liquid storage area 12 is disposed below the flash chamber 11. The refrigerant inlet 101 and the liquid outlet 103 are both provided on the housing 31, and the vapor outlet 102 and the high-pressure stage suction port 35 are both disposed within the housing 31. That is, the flash tank 10 is a structure that is cast and molded integrally with the multi-stage compressor. The flash chamber 11 and the liquid storage area 12 (generally, a liquid storage tank structure or a liquid storage chamber structure) are formed within the housing 31, and the refrigerant inlet 101 and the liquid outlet 103 are formed at corresponding positions on the housing 31.

[0026] Furthermore, in this embodiment, the vapor outlet 102 and the high-pressure stage inlet 35 (the inlet of the high-pressure stage structure of the multi-stage compressor) are structurally merged into the high-pressure stage inlet. That is, the high-pressure stage inlet is both the original inlet and the vapor outlet 102 of the flash chamber 11. The refrigerant vapor formed by the rapid evaporation in the flash chamber 11 directly enters the high-pressure stage inlet 35. Of course, in other embodiments not shown, the vapor outlet 102 and the high-pressure stage inlet 35 may be in communication with each other by a pipeline or by a channel formed in the compressor.

[0027] The high-pressure stage structure 32 and the low-pressure stage structure 33 are provided in a housing 31, the low-pressure stage structure 33 is configured to perform a first stage compression of the refrigerant, the high-pressure stage structure 32 is configured to perform a second stage compression of the refrigerant, and the flash tank 10 is disposed between the high-pressure stage structure 32 and the low-pressure stage structure 33. That is, the flash tank 10 is disposed at the intermediate pressure stage position of the multi-stage compressor. The advantage of such a configuration is that the size of the entire compressor can be reduced, making the entire compressor have a more compact structure and reducing the installation area.

[0028] In order to further utilize the internal structural space of the multi-stage compressor, in this embodiment, the high pressure stage structure 32 and the low pressure stage structure 33 are symmetrically arranged and connected by a coupler 34, the flash chamber 11 is located at the position of the coupler 34, and the liquid storage area 12 is located below the coupler 34. The high pressure stage structure and the low pressure stage structure are in a mirror arrangement and connected by a coupler.

[0029] The refrigerant inlet 101 communicates with the flash chamber 11 and is disposed above the flash chamber 11, and the liquid outlet 103 communicates with the liquid storage area 12. By utilizing the action of gravity, the refrigerant inlet 101 is disposed above the flash chamber 11, so that the liquid refrigerant formed after evaporation of the refrigerant (refrigerant) entering the flash chamber 11 falls along the inner wall of the housing into the liquid storage area 12 under the action of gravity, and the liquid outlet 103 introduces the saturated liquid refrigerant accumulated to a certain level into the evaporator 22.

[0030] In some embodiments, the baffle plate 13 is provided in the housing 31, and the baffle plate 13 is arranged between the connector 34 and the liquid storage area 12. The provision of the baffle plate 13 makes it possible, on the one hand, to increase the turbulence of the cryogen to achieve rapid evaporation, and, on the other hand, to avoid the liquid cryogen being carried away from the flash tank by the airflow during the suction process. Naturally, in other embodiments not shown, the baffle plate 13 can be replaced by a porous filter screen, which is essentially the same in basic structure as the present embodiment, with the difference that the porous filter screen is provided in the housing 31, and the porous filter screen is arranged between the connector 34 and the liquid storage area 12. The porous filter screen serves to filter oil, while preventing liquid from being carried away during suction.

[0031] The multi-stage compressor of this embodiment is a two-stage compressor, and is a screw compressor.

[0032] The refrigerant from the condenser 21 and after passing through the throttling element 23 enters the flash chamber 11 at low pressure through the refrigerant inlet 101 above the connector 34, where it rapidly evaporates to generate refrigerant vapor, then enters the high pressure stage of the multi-stage compressor together with the intake air flow to undergo two-stage compression. Another part of the refrigerant cools down to form saturated liquid refrigerant that accumulates in the liquid storage area 12 at the bottom of the flash tank 10, and after accumulating to a certain level, the refrigerant at the bottom of the flash tank 10 exits through the liquid outlet 103 and is further restricted by the second throttling element 24 (which may be a throttling orifice plate, electronic expansion valve, etc.) in the main loop, then enters the evaporator 22 to undergo heat transfer and evaporation, and then is sucked into the compressor, thereby completing the full cycle.

[0033] As shown in FIG. 3, according to embodiment II of the present disclosure, a multi-stage compressor including a flash tank 10 is provided. The flash tank 10 is disposed in the multi-stage compressor. A refrigerant inlet 101 of the flash tank 10 is configured to communicate with a condenser 21, a vapor outlet 102 of the flash tank 10 is configured to communicate with a high-pressure stage suction port of the multi-stage compressor, and a liquid outlet 103 of the flash tank 10 is configured to communicate with an evaporator 22. The flash tank 10 includes a tank structure 10' disposed inside the multi-stage compressor, and the tank structure 10' forms a flash chamber 11 and a liquid storage area 12 of the flash tank 10.

[0034] In this embodiment, the tank structure 10' is disposed at the discharge side of the multi-stage compressor. Referring to the refrigerant flow direction arrow for the multi-stage compressor in Figure 3, the right side is the discharge side of the multi-stage compressor. The refrigerant from the condenser 21 enters into the tank structure 10' from the bottom pipeline and flash evaporates, then the gas enters the intermediate pressure stage from the above pipeline, and the refrigerant liquid is restrained from flowing from the bottom of the side, and then returns to the evaporator 22.

[0035] The tank structure 10' can be arranged at a position according to the structure and the internal space of the multi-stage compressor. In another embodiment not shown, the high pressure stage structure 32 and the low pressure stage structure 33 may be provided in the multi-stage compressor, and the tank structure 10' is arranged between the high pressure stage structure 32 and the low pressure stage structure 33. This allows the tank structure to be arranged closer to or at the intermediate pressure stage, thereby reducing the refrigerant flow distance.

[0036] According to embodiment II of the present disclosure, there is provided an air conditioning unit including the multi-stage compressor of the above embodiment.

[0037] The refrigerant inlet cycle of the air conditioning unit includes a condenser 21 and an evaporator 22. The condenser 21 communicates with the refrigerant inlet 101 of the flash tank 10, and the evaporator 22 communicates with the liquid outlet 103 of the flash tank 10.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting to the exemplary embodiments according to the present application. As used herein, the singular forms are intended to include the plural forms unless the context clearly dictates otherwise. Furthermore, it should be understood that the terms "comprise" and / or "include" as used herein indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0039] It should be noted that in the specification and claims of this application, as well as in the drawings described above, terms such as "first," "second," and the like are used to distinguish between similar objects and are not necessarily used to describe a particular sequence or order. Such uses should be understood to be interchangeable in appropriate circumstances such that the embodiments of the application described herein can be performed in sequences other than those illustrated or described herein.

[0040] Of course, the preferred embodiments of the present disclosure are described above. It should be noted that those skilled in the art can also make some improvements and modifications without departing from the basic principles of the present disclosure, and these improvements and modifications should also fall within the protection scope of the present disclosure.

Claims

1. A multi-stage compressor comprising a flash tank (10), wherein the flash tank (10) is disposed within the multi-stage compressor, a refrigerant inlet (101) of the flash tank (10) is configured to communicate with a condenser (21), a vapor outlet (102) of the flash tank (10) communicates with a high-pressure stage suction port (35) of the multi-stage compressor, and a liquid outlet (103) of the flash tank (10) is configured to communicate with an evaporator (22).

2. The multi-stage compressor according to claim 1, further comprising a housing (31) formed with a flash chamber (11) and a liquid storage region (12) of the flash tank (10), wherein the liquid storage region (12) is disposed below the flash chamber (11), the refrigerant inlet (101) and the liquid outlet (103) are both provided on the housing (31), and the vapor outlet (102) and the high-pressure stage suction port (35) are both disposed within the housing (31).

3. The multi-stage compressor according to claim 2, further comprising a high-pressure stage structure (32) and a low-pressure stage structure (33) provided within the housing (31), wherein the flash tank (10) is disposed between the high-pressure stage structure (32) and the low-pressure stage structure (33).

4. The high-pressure stage structure (32) and the low-pressure stage structure (33) are symmetrically disposed and connected by a connector (34), the flash chamber (11) is disposed at a position of the connector (34), and the liquid storage region (12) is disposed below the connector (34).

5. The refrigerant inlet (101) communicates with the flash chamber (11) and is disposed above the flash chamber (11), the liquid outlet (103) communicates with the liquid storage region (12).

6. The baffle plate (13) is provided in the housing (31), and the baffle plate (13) is disposed between the coupler (34) and the liquid storage region (12). The multi-stage compressor according to claim 4.

7. The porous filter screen is provided in the housing (31), and the porous filter screen is disposed between the coupler (34) and the liquid storage region (12). The multi-stage compressor according to any one of claims 2 to 4.

8. The flash tank (10) includes a tank structure (10') disposed inside the multi-stage compressor, and the tank structure forms a flash chamber (11) of the flash tank (10) and a liquid storage region (12). The multi-stage compressor according to claim 1.

9. The tank structure (10') is disposed on the exhaust side of the multi-stage compressor. The multi-stage compressor according to claim 8.

10. The multi-stage compressor further includes a high-pressure stage structure (32) and a low-pressure stage structure (33) provided therein, and the tank structure (10') is disposed between the high-pressure stage structure (32) and the low-pressure stage structure (33). The multi-stage compressor according to claim 8 or 9.

11. The multi-stage compressor is a two-stage compressor. The multi-stage compressor according to any one of claims 1 to 4.

12. An air conditioning unit including the multi-stage compressor according to any one of claims 1 to 4, 6, 8, and 9.

13. The air conditioning unit further includes the condenser (21) and the evaporator (22), the condenser (21) communicates with the refrigerant inlet (101) of the flash tank (10), and the evaporator (22) communicates with the liquid outlet (103) of the flash tank (10). The air conditioning unit according to claim 12.

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