A refrigeration cycle system

Abstract

The application provides a refrigeration cycle system. The refrigeration cycle system comprises: a first compressor configured to suck refrigerant of a low-pressure side component in the refrigeration cycle, compress the refrigerant, and discharge the compressed refrigerant, and the first compressor comprises an aerostatic bearing configured to support a rotor of the compressor by using lubricating gas provided by a lubricating gas inlet, and the lubricating gas inlet; a gas supply pipeline connected between the low-pressure side component and the lubricating gas inlet and used to supply part of refrigerant gas in the low-pressure side component to the lubricating gas inlet as lubricating gas. The refrigeration cycle system of the application separately provides the gas supply pipeline, uses the gas supply pipeline to separately provide lubricating gas for the aerostatic bearing, and solves the problem of slow start of the aerostatic bearing centrifugal compressor in the prior art. Moreover, the gas supply pipeline obtains the lubricating gas from the low-pressure side component of the system, and the energy consumption required for supplying gas to the aerostatic bearing is also reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of compressors, and in particular to a refrigeration cycle system. BACKGROUND

[0002] In a static pressure gas bearing, the frictional resistance between the gas and the rotor is small, and compared with a magnetic bearing, the static pressure gas bearing does not need a complicated control system, and has a simple structure and low cost, so in recent years, the static pressure gas bearing has been applied to centrifugal compressors. Since the static pressure gas bearing uses an external gas supply to provide its suspension pressure, in order to make the static pressure gas bearing work stably, a reasonable gas supply system design is particularly important.

[0003] In the existing gas supply scheme, one is to use a liquid pump to extract liquid refrigerant from a condenser, and then after passing through a throttling device and a gas-liquid separator, the liquid refrigerant is supplied to the static pressure gas bearing. The entire system structure is relatively complex, and since there is a throttling process, the effective energy loss is large. The second scheme is to heat and evaporate the liquid refrigerant, and then deliver the gaseous refrigerant to the static pressure gas bearing. This scheme leads to high energy consumption of the gas supply, and the gas supply is discontinuous, which affects the stability of the static pressure gas bearing. SUMMARY

[0004] An object of the present application is to provide a refrigeration cycle system that can at least solve any of the above problems.

[0005] A further object of the present application is to solve the problem of slow start of a gas suspension bearing compressor.

[0006] Another further object of the present application is to solve the problem of excessive energy consumption of the gas supply of a gas suspension bearing.

[0007] Another further object of the present application is to solve the problem of unstable gas supply pressure of a gas suspension bearing.

[0008] In particular, the present application provides a refrigeration cycle system, comprising a first compressor configured to suck refrigerant of a low-pressure side component in a refrigeration cycle, compress the refrigerant, and discharge the compressed refrigerant, and the first compressor comprises a gas suspension bearing configured to support a rotor of the compressor by using lubricating gas provided by a lubricating gas inlet, and a gas supply pipeline connected between the low-pressure side component and the lubricating gas inlet, and used to supply part of refrigerant gas in the low-pressure side component to the lubricating gas inlet as lubricating gas.

[0009] Further, the low-pressure side component comprises an evaporator, which comprises a first refrigerant outlet connected to the first compressor, and used to supply refrigerant to the first compressor, and a second refrigerant outlet connected to the gas supply pipeline, and used to supply lubricating gas.

[0010] Furthermore, the refrigeration cycle system also includes a second compressor located in the gas supply line for compressing the lubricating gas supplied from the second refrigerant outlet.

[0011] Furthermore, the second compressor is an oil-free compressor.

[0012] Furthermore, the second compressor is either an air-float compressor or a magnetic levitation compressor.

[0013] Furthermore, the refrigeration cycle system also includes a pressure stabilizing device disposed between the second compressor and the lubricating gas inlet, used to stabilize the pressure of the lubricating gas flowing from the second compressor to the first compressor.

[0014] Furthermore, the refrigeration cycle system also includes a filter, located between the second compressor and the second refrigerant outlet, for filtering the lubricating gas flowing from the evaporator to the second compressor.

[0015] Furthermore, the refrigeration cycle system also includes a one-way valve, which is located between the second compressor and the pressure regulator to allow lubricating gas to flow unidirectionally from the second compressor to the pressure regulator.

[0016] Furthermore, the first compressor is a centrifugal compressor and includes a first compression chamber and a second compression chamber; the first compression chamber and the second compression chamber are respectively connected to the gas supply pipeline through a lubricating gas inlet.

[0017] Furthermore, the air suspension bearing is a hydrostatic gas bearing.

[0018] In the refrigeration cycle system provided by this invention, the first compressor serves as the compression power source for the refrigeration cycle system, providing power for the refrigerant flow. An air-bearing bearing supports the rotor within the first compressor. The air-bearing bearing is equipped with a lubricating gas inlet connected to a gas supply line. The gas supply line is located between the low-pressure side component of the refrigeration cycle system and the lubricating gas inlet of the air-bearing bearing, providing lubricating gas to the air-bearing bearing. Compared to the prior art method of using a portion of the drawn-in refrigerant for air-bearing bearing lubrication, the refrigeration cycle system of this invention has a dedicated gas supply line, which separately provides lubricating gas for the air-bearing bearing, thus solving the problem of slow start-up in existing air-bearing centrifugal compressors.

[0019] Furthermore, the low-pressure side component includes an evaporator, comprising: a first refrigerant outlet connected to the first compressor for supplying refrigerant to the first compressor; and a second refrigerant outlet connected to the gas supply line for supplying the lubricating gas. The evaporator serves as both a low-pressure side device in the refrigeration cycle system and a means of supplying lubricating gas to the gas supply line via the second refrigerant outlet. Obtaining the lubricating gas directly from the evaporator also reduces the energy consumption required to supply gas to the air suspension bearing.

[0020] Furthermore, a second compressor, located in the gas supply pipeline, is used to compress the lubricating gas supplied from the second refrigerant outlet; a pressure stabilizing device, located between the second compressor and the lubricating gas inlet, is used to stabilize the pressure of the lubricating gas flowing from the second compressor to the first compressor. The pressure stabilizing device solves the problem of unstable gas supply pressure for the air suspension bearing, enabling the air suspension bearing to operate more continuously.

[0021] The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0022] The following sections will describe some specific embodiments of the invention in detail by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or portions. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0023] Figure 1 This is a schematic diagram of a refrigeration cycle system according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the gas supply pipeline of a refrigeration cycle system according to an embodiment of the present invention. Detailed Implementation

[0025] Figure 1 This is a schematic diagram of a refrigeration cycle system according to an embodiment of the present invention.

[0026] refer to Figure 1 In some embodiments, the refrigerant circulation system includes: a first compressor 10, an evaporator 20, a condenser 30, an expansion valve 40, and a gas supply line 100. The first compressor 10 draws in gaseous refrigerant from the evaporator 20, compresses the gaseous refrigerant to a high-temperature, high-pressure state, and inputs it into the condenser 30. The high-temperature, high-pressure refrigerant is condensed by the condenser 30 and converted into a high-temperature, high-pressure liquid refrigerant. After being depressurized by the expansion valve 40, it becomes a low-temperature, low-pressure liquid refrigerant and enters the evaporator 20. The gaseous refrigerant absorbs heat and evaporates in the evaporator 20, becoming a low-temperature, low-pressure gaseous refrigerant, and then returns to the first compressor 10 for the next refrigeration cycle.

[0027] In some embodiments, the first compressor 10 includes an air suspension bearing (not shown) configured to support the compressor rotor, thereby keeping the compressor rotor in a suspended state. The air suspension bearing can be a hydrostatic gas bearing or a thrust bearing.

[0028] The first compressor 10 may be a centrifugal compressor and includes two compression chambers. An air-suspension bearing is internally provided in the first compressor 10, and a lubricating gas inlet 101 is externally provided for connecting to the air-suspension bearing. The lubricating gas inlet 101 is used to connect to a gas supply line 100 to obtain lubricating gas for supplying the air-suspension bearing. In other embodiments, the first compressor 10 may also be other types of compressors, such as screw compressors, vane compressors, etc.

[0029] The gas supply line 100 is connected between the low-pressure side component of the refrigeration cycle and the lubricating gas inlet 101, and is used to supply a portion of the refrigerant gas in the low-pressure side component of the refrigeration cycle to the lubricating gas inlet 101 as the lubricating gas. The gas supply line 100 is specifically designed separately for the air suspension bearing to avoid the problem that the refrigerant drawn in when the first compressor 10 starts needs to be supplied to both the air suspension bearing for lubrication and the refrigeration cycle at the same time, which would cause the first compressor 10 to start slowly.

[0030] In this embodiment, the low-pressure side component of the refrigeration cycle refers to the component on the side with lower refrigerant pressure, which can also be understood as the device upstream of the refrigerant flow direction of the first compressor 10. The low-pressure side component may include an evaporator 20, which includes a first refrigerant outlet 202, a second refrigerant outlet 204, and a lubricating gas return port 203. The first refrigerant outlet 202 is connected to the first compressor 10 and is used to supply refrigerant to the first compressor 10; the second refrigerant outlet 204 is connected to the gas supply line 100 and is used to supply lubricating gas. Because the lubricating gas is taken from the low-pressure side component of the refrigeration cycle system and supplied to the air suspension bearing, energy loss is reduced.

[0031] The first compressor 10 draws in gaseous refrigerant from the evaporator 20 through the first refrigerant outlet 202, then compresses the gaseous refrigerant and supplies it to the condenser 30. The gaseous refrigerant is condensed into high-pressure liquid refrigerant in the condenser 30, then enters the expansion valve 40 to reduce its pressure, and then returns to the evaporator 20. This process constitutes the main refrigeration cycle.

[0032] In addition to the main refrigeration cycle, an extra gas supply line 100 is provided. Part of the refrigerant in the evaporator 20 enters the gas supply line 100 through the second refrigerant outlet 204, and enters the first compressor 10 through the lubricating gas inlet 101, serving as the lubricating gas for the air suspension bearing.

[0033] Figure 2 This is a schematic diagram of the gas supply pipeline of a refrigeration cycle system according to an embodiment of the present invention. (Reference) Figure 2 In some embodiments, the main components of the gas supply line 100 are, in sequence, a first compressor 10, an evaporator 20, a filter 130, a second compressor 140, a one-way valve 150, and a pressure stabilizing device 160.

[0034] The first compressor 10 is a centrifugal compressor and includes two compression chambers: a first compression chamber 110 and a second compression chamber 120. The first compression chamber 110 includes an air suspension bearing (not shown in the figure) and is provided with a first lubricating gas inlet 111. The second compression chamber 120 also includes an air suspension bearing (not shown in the figure) and is provided with a second lubricating gas inlet 121. Both the first lubricating gas inlet 111 and the second lubricating gas inlet 121 belong to the lubricating gas inlet 101 and are connected to the gas supply pipeline 100 to obtain lubricating gas to supply the air suspension bearings in the first compression chamber 110 and the second compression chamber 120, respectively.

[0035] The second compressor 140 is disposed in the gas supply line 100 and is used to compress the lubricating gas supplied from the second refrigerant outlet 204. The second compressor 140 may be a small-flow compressor with a smaller flow rate than the first compressor 10, and the second compressor 140 is an oil-free compressor, such as an air-float compressor or a magnetic levitation compressor. Using an oil-free compressor for the second compressor 140 avoids contamination of the refrigerant by lubricating oil. In other embodiments, the second compressor 140 may obtain refrigerant from multiple locations on the low-pressure side of the main refrigeration circuit.

[0036] A filter 130 is disposed between the second compressor 140 and the second refrigerant outlet 204 to filter the lubricating gas flowing from the evaporator 20 to the second compressor 140.

[0037] The pressure stabilizing device 160 is located between the second compressor 140 and the lubricating gas inlet 106 to stabilize the pressure of the lubricating gas flowing from the second compressor 140 to the first compressor 10, thereby solving the problem of unstable gas pressure when supplying gas to the air suspension bearing.

[0038] A one-way valve 150 is disposed between the second compressor 140 and the pressure regulator 160, so that the lubricating gas flows unidirectionally from the second compressor 140 to the pressure regulator 160.

[0039] like Figure 2As shown, in some embodiments, the second compressor 140 in the gas supply line 100 draws a portion of refrigerant from the evaporator 20, which is then supplied as lubricating gas to the air suspension bearings. The lubricating gas enters the second compressor 140 after being filtered by filter 130, which prevents liquid refrigerant from entering the second compressor 140 and causing damage. The refrigerant, pressurized by the second compressor 140, enters the pressure stabilizing device 160 through a one-way valve 150. The one-way valve 150 is designed to prevent refrigerant backflow into the second compressor 140 due to pressure differences in the pipeline. The pressure stabilizing device 160 stabilizes the lubricating gas, maintaining a stable pressure input to the first lubricating gas inlet 111 and the second lubricating gas inlet 121, supplying the air suspension bearings in the first compression chamber 110 and the second compression chamber 120, thereby ensuring the smooth operation of the air suspension bearings in the first compression chamber 110 and the second compression chamber 120. The lubricating gas, having completed its lubrication task, returns to the evaporator 20 through the lubricating gas outlet 104, completing the refrigerant circulation within the gas supply line 100. By supplying gas to the air suspension bearing in the first compressor 10 through the gas supply line 100, the problem of slow start-up of the first compressor 10 is solved. Drawing gas from the evaporator 20 reduces energy consumption when supplying gas to the air suspension bearing. A filter 130 is installed to remove liquid refrigerant, preventing it from entering the second compressor 140 and causing damage. The second compressor 140 is configured as an oil-free compressor to avoid lubricating oil contaminating the refrigerant. A pressure stabilizing device 160 addresses the problem of unstable gas supply pressure to the air suspension bearing, enabling it to operate stably for extended periods.

[0040] Therefore, those skilled in the art should recognize that although numerous exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the invention. Thus, the scope of the present invention should be understood and construed as covering all such other variations or modifications.

Claims

1. A refrigeration cycle system comprising: a first compressor configured to take in refrigerant of a low-pressure side component in a refrigeration cycle and discharge the taken-in refrigerant after compression, and the first compressor includes an aerostatic bearing configured to support a rotor of the compressor with lubrication gas supplied from a lubrication gas inlet, and the lubrication gas inlet; a gas supply line connected between the low-pressure side component and the lubrication gas inlet and configured to supply part of refrigerant gas in the low-pressure side component to the lubrication gas inlet as the lubrication gas.

2. The refrigeration cycle system according to claim 1, wherein the low-pressure side component includes: an evaporator including: a first refrigerant outlet connected to the first compressor and configured to supply refrigerant to the first compressor; a second refrigerant outlet connected to the gas supply line and configured to supply the lubrication gas.

3. The refrigeration cycle system according to claim 2, further comprising: a second compressor provided in the gas supply line and configured to compress the lubrication gas supplied from the second refrigerant outlet.

4. The refrigeration cycle system according to claim 3, wherein the second compressor is an oil-free compressor.

5. The refrigeration cycle system according to claim 4, wherein, the second compressor is an aerostatic compressor or a magnetic bearing compressor.

6. The refrigeration cycle system according to claim 3, further comprising: a pressure stabilizing device provided between the second compressor and the lubrication gas inlet and configured to stabilize pressure of the lubrication gas flowing from the second compressor to the first compressor.

7. The refrigeration cycle system according to claim 3, further comprising: a filter provided between the second compressor and the second refrigerant outlet and configured to filter the lubrication gas flowing from the evaporator to the second compressor.

8. The refrigeration cycle system according to claim 6, wherein a check valve is provided between the second compressor and the pressure stabilizing device and configured to allow one-way flow of the lubrication gas from the second compressor to the pressure stabilizing device.

9. The refrigeration cycle system according to claim 1, wherein the first compressor is a centrifugal compressor and includes a first compression chamber and a second compression chamber; the first compression chamber and the second compression chamber are connected to the lubrication gas inlet and the gas supply line, respectively.

10. The refrigeration cycle system according to claim 1, wherein, the aerostatic bearing is a static pressure gas bearing.

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