Compressor unit for ammonia refrigeration system, anti-surge control method and ammonia refrigeration system

Abstract

The embodiment of the application discloses a compressor unit applied to an ammonia refrigeration system, an anti-surge control method and the ammonia refrigeration system. The compressor unit comprises: a first compressor, which can compress low-temperature and low-pressure ammonia gas to form one-stage compressed ammonia gas; a second compressor, which can compress the one-stage compressed ammonia gas and the low-temperature and low-pressure ammonia gas to finally obtain target compressed ammonia gas; an ammonia inlet circuit, which is arranged between an ammonia gas supply assembly and the first compressor and between the ammonia gas supply assembly and the second compressor; a return gas circuit, which is arranged between the first compressor and the ammonia inlet circuit and between the second compressor and the ammonia inlet circuit; an outlet gas circuit, which is in communication with the second compressor; and an anti-surge circuit, an inlet end of the anti-surge circuit being in communication with the outlet gas circuit, and an outlet end of the anti-surge circuit being in communication with the ammonia inlet circuit.

Description

Technical Field

[0001] This application relates to the field of compressor anti-surge technology, and in particular to a compressor unit for an ammonia refrigeration system, an anti-surge control method, and an ammonia refrigeration system. Background Technology

[0002] The compressor unit in the ammonia refrigeration system can compress low-temperature and low-pressure ammonia gas to obtain high-temperature and high-pressure ammonia gas for use by subsequent equipment. However, during the operation of the compressor, insufficient flow at the inlet or excessive pressure at the outlet may cause the compressor to surge. In order to avoid compressor surge as much as possible, related technologies often design a corresponding number of anti-surge circuits based on the number of compressor inlets. This results in a large number of pipelines in the compressor unit, high construction costs, and greater maintenance difficulties. Summary of the Invention

[0003] This application discloses a compressor unit for an ammonia refrigeration system, an anti-surge control method, and an ammonia refrigeration system. By setting an anti-surge circuit for a three-stage compression compressor unit, the pipeline structure of the compressor unit is simplified, reducing construction costs and maintenance difficulty.

[0004] To achieve the above objectives, in a first aspect, embodiments of this application disclose a compressor unit for an ammonia refrigeration system, the ammonia refrigeration system including an ammonia supply assembly capable of outputting low-temperature, low-pressure ammonia gas, and the compressor unit comprising: Steam turbine; The first compressor is coaxially arranged with the steam turbine so that the steam turbine can drive the first compressor to work. The first compressor can compress the low-temperature and low-pressure ammonia gas to form a section of compressed ammonia gas. The second compressor is located on the side of the first compressor away from the steam turbine. The second compressor is coaxially connected to the steam turbine so that the steam turbine can drive the second compressor to work. The second compressor can compress the first-stage compressed ammonia and the low-temperature, low-pressure ammonia to finally obtain the target compressed ammonia. An air intake circuit is provided between the ammonia supply component and the first compressor, and between the ammonia supply component and the second compressor; A return air path is provided between the first compressor and the intake circuit, and between the second compressor and the intake circuit; The exhaust gas path is connected to the second compressor; An anti-surge circuit, wherein the air inlet of the anti-surge circuit is connected to the air outlet, and the air outlet of the anti-surge circuit is connected to the air inlet circuit.

[0005] In one possible implementation, the intake circuit includes: An intake air passage is connected to the first compressor, and the outlet of the anti-surge circuit is connected to the intake air passage. The low-temperature, low-pressure ammonia gas can enter the first compressor through the intake air passage. The first gas filling path is connected to the second compressor. The low-temperature and low-pressure ammonia gas can be mixed with the first stage of compressed ammonia gas through the first gas filling path to form a first stage of mixed ammonia gas, which then enters the second compressor. The second compressor compresses the first stage of mixed ammonia gas to obtain a second stage of compressed ammonia gas. The second gas filling path is connected to the second compressor. The low-temperature, low-pressure ammonia gas can be mixed with the two-stage compressed ammonia gas through the second gas filling path to form a two-stage mixed ammonia gas before entering the second compressor. The second compressor can compress the two-stage mixed ammonia gas to obtain the target compressed ammonia gas.

[0006] In one possible implementation, the return gas path includes: The first return gas path has an inlet end connected to the first compressor and an outlet end connected to the first gas filling path. The compressed ammonia gas can enter the second compressor through the first return gas path. The second return gas path has an inlet end connected to the second compressor and an outlet end connected to the second gas filling path. The two-stage compressed ammonia gas can re-enter the second compressor through the second return gas path.

[0007] In one possible implementation, the first compressor includes: The first air inlet is connected to the aforementioned section of the air intake passage; The first air outlet is connected to the air inlet of the first return air path.

[0008] In one possible implementation, the intake air passage includes: An intake pipe is connected to the ammonia supply assembly and the first intake port; A gas return port is provided in the section of the air inlet pipe, and the gas return port is connected to the air outlet of the anti-surge circuit.

[0009] In one possible implementation, the second compressor includes: The second air inlet is connected to the first refueling air passage; The second air outlet is connected to the air inlet of the second return air path; The third air inlet is connected to the second refueling air passage; The main air outlet is connected to the air outlet path.

[0010] In one possible implementation, the anti-surge circuit includes: A return pipe, wherein the inlet end of the return pipe is connected to the outlet air passage, and the outlet end of the return pipe is connected to the inlet air passage. An anti-surge valve is installed in the return pipe. When the compressor unit experiences surge, the anti-surge valve can open to allow the target compressed ammonia gas to flow through the return pipe to the first section of the intake air path.

[0011] In one possible implementation, the ammonia refrigeration system further includes a liquid ammonia supply assembly, and the anti-surge circuit further includes: A cooling pipeline is provided between the liquid ammonia supply component and the return pipeline. The cooling pipeline is used to introduce liquid ammonia from the liquid ammonia supply component into the return pipeline to cool the target compressed ammonia gas in the return pipeline. A temperature control valve is installed on the cooling pipeline. The temperature control valve can open when the temperature in the return pipeline reaches a predetermined temperature.

[0012] In one possible implementation, the compressor unit further includes: A first monitoring component is installed in the air intake circuit; The second monitoring component is installed in the return gas path; The third monitoring component is located in the outlet gas path.

[0013] Secondly, embodiments of this application provide an anti-surge control method, applied to a compressor unit for an ammonia refrigeration system as described in any one of the first aspects above, the anti-surge control method comprising: A first surge curve and a second surge curve are generated based on the expected performance of the first compressor and the second compressor and historical surge data, respectively. The first surge curve and the second surge curve are deviated from the first direction by a first distance, respectively, to obtain a first anti-surge curve and a second anti-surge curve. Acquire the first intake data at the first intake port, the first exhaust data at the first outlet, the second intake data at the second intake port, and the target gas data at the total outlet. Based on the first intake data and the first exhaust data, a first actual operating point is determined, and based on the positional relationship between the first actual operating point and the first anti-surge curve satisfying a first preset condition, the anti-surge valve is controlled to open; and / or Based on the second intake data and the target gas data, a second actual operating point is determined, and based on the second actual operating point and the second anti-surge curve, the positional relationship between the second actual operating point and the second anti-surge curve satisfies a second preset condition, the anti-surge valve is controlled to open.

[0014] Thirdly, embodiments of this application provide an ammonia refrigeration system, comprising: Compressor unit for ammonia refrigeration system as described in any one of the first aspects above; A liquid ammonia supply assembly is connected to the compressor unit; The ammonia supply component is connected to the compressor unit.

[0015] Thus, the compressor unit for an ammonia refrigeration system provided in this application embodiment drives a first compressor and a second compressor coaxially via a steam turbine, and incorporates an anti-surge circuit. This ensures the compressor unit can mitigate surge while simultaneously reducing construction costs. Furthermore, the series connection of single-cylinder and multi-cylinder compressors optimizes the matching between compression stages. The single-cylinder compressor, the multi-cylinder compressor, and the different compression cylinders of the multi-cylinder compressor are connected via a return gas path, ensuring smooth flow of ammonia between different compression stages. The anti-surge circuit rapidly reduces outlet pressure and increases inlet flow when surge occurs in the compressor unit, thereby improving the stability and safety of the compressor unit's operation.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This application provides a schematic diagram of the structure of a compressor unit for an ammonia refrigeration system. Figure 2 This is a second schematic diagram of the structure of a compressor unit for an ammonia refrigeration system provided in an embodiment of this application; Figure 3 This is shown as a third schematic diagram of the structure of a compressor unit for an ammonia refrigeration system according to an embodiment of this application; Figure 4 A flowchart illustrating an anti-surge control method provided in an embodiment of this application is shown.

[0019] Explanation of reference numerals in the attached figures: 10-Compressor unit, 101-Steam turbine, 102-First compressor, 1021-First air inlet, 1022-First air outlet, 103-Second compressor, 1031-Second air inlet, 1032-Second air outlet, 1033-Third air inlet, 1034-Main air outlet, 104-Intake circuit, 1041-First intake air path, 1042-First intake pipe, 1043-Gas return port, 1044-First gas filling air path, 10 45-Second gas filling line, 105-Return gas line, 1051-First return gas line, 1052-First cooler, 1053-Second return gas line, 1054-Second cooler, 106-Outlet gas line, 107-Anti-surge circuit, 1071-Return pipe, 1072-Anti-surge valve, 1073-Cooling pipe, 1074-Temperature control valve, 1081-First monitoring component, 1082-Second monitoring component, 1083-Third monitoring component. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0022] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0024] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0025] Ammonia refrigeration systems use ammonia as a refrigerant to provide cooling for various processes in food processing, refrigeration, and petrochemical industries. During operation, a turbine drives a compressor to compress low-temperature, low-pressure ammonia gas into high-temperature, high-pressure ammonia gas. However, during actual operation, compressor surge may occur due to changes in flow rates at the compressor's inlets or variations in the demand from downstream equipment. Compressor surge not only shortens the compressor's lifespan but can also, in severe cases, threaten the safety of personnel. Therefore, please refer to... Figures 1 to 3 This application provides a compressor unit 10 for an ammonia refrigeration system. The compressor unit 10 is applied in the ammonia refrigeration system, which includes an ammonia supply assembly capable of outputting low-temperature, low-pressure ammonia. The compressor unit 10 includes a steam turbine 101, which is capable of operating under the drive of steam.

[0026] The ammonia refrigeration system includes a boiler that generates high-temperature and high-pressure steam and sends the steam into a steam turbine 101. The impeller of the steam turbine 101 rotates after being impacted by the high-temperature and high-pressure steam, thereby converting the kinetic energy of the steam into mechanical energy.

[0027] The compressor unit 10 includes a first compressor 102. The first compressor 102 is coaxially arranged with the steam turbine 101 so that the steam turbine 101 can drive the first compressor 102 to work. The first compressor 102 can compress low-temperature and low-pressure ammonia gas to form a compressed ammonia gas.

[0028] When the steam turbine 101 starts working under the drive of steam, it can drive the first compressor 102, which is coaxially arranged with the steam turbine 101, to work, thereby enabling the first compressor 102 to compress the low-temperature and low-pressure ammonia gas entering the first compressor 102, and thus obtain a section of compressed ammonia gas.

[0029] The compressor unit 10 includes a second compressor 103. The second compressor 103 is located on the side of the first compressor 102 away from the turbine 101. The second compressor 103 is coaxially connected to the turbine 101 so that the turbine 101 can drive the second compressor 103 to work. The second compressor 103 can compress a section of compressed ammonia and low-temperature, low-pressure ammonia to finally obtain the target compressed ammonia.

[0030] The second compressor 103 is also coaxially mounted with the steam turbine 101, enabling the steam turbine 101 to drive both the first compressor 102 and the second compressor 103 simultaneously. The second compressor 103 can compress both the first-stage compressed ammonia from the first compressor 102 and the low-temperature, low-pressure ammonia directly entering the second compressor 103. Preferably, the second compressor 103 can be a multi-cylinder compressor, thus achieving two-stage compression of the ammonia. The combination of the second compressor 103 and the first compressor 102 enables three-stage compression of the low-temperature, low-pressure ammonia, ultimately yielding the target compressed ammonia.

[0031] The compressor unit 10 includes an intake circuit 1044. The intake circuit 1044 is disposed between the ammonia supply assembly and the first compressor 102, and between the ammonia supply assembly and the second compressor 103.

[0032] The intake circuit 1044 includes multiple intake air passages, the intake ends of which are all connected to the ammonia supply component, and the outlet ends of which are connected to the first compressor 102 or the second compressor 103, so that low-temperature, low-pressure ammonia can flow into the compression cylinders of the first compressor 102 and the second compressor 103 respectively through the intake circuit 1044.

[0033] The compressor unit 10 includes a return air passage 105. The return air passage 105 is located between the first compressor 102 and the intake circuit 1044, and between the second compressor 103 and the intake circuit 1044.

[0034] Since the compressor unit 10 includes a first compressor 102 and a second compressor 103, and the second compressor 103 is a multi-cylinder compressor, the first stage of compressed ammonia gas generated by the first compressor 102 can flow into the intake circuit 1044 of the low-pressure cylinder connected to the second compressor 103 via the return gas passage 105, and the second stage of compressed ammonia gas generated in the low-pressure cylinder of the second compressor 103 can flow into the intake circuit 1044 of the high-pressure cylinder connected to the second compressor 103 via the return gas passage 105.

[0035] The compressor unit 10 includes an exhaust gas passage 106. The exhaust gas passage 106 is connected to the second compressor 103.

[0036] The outlet gas passage 106 of the compressor unit 10 is connected to the high-pressure cylinder of the second compressor 103, so that the target compressed ammonia gas generated in the high-pressure cylinder of the second compressor 103 can flow out of the second compressor 103 through the outlet gas passage 106 and flow to the subsequent equipment.

[0037] The compressor unit 10 includes an anti-surge circuit 107. The inlet end of the anti-surge circuit 107 is connected to the outlet air passage 106, and the outlet end of the anti-surge circuit 107 is connected to the inlet air passage 1044.

[0038] The anti-surge circuit 107 is disposed between the outlet air passage 106 and the inlet air passage 1044 connected to the first compressor 102. The inlet end of the anti-surge circuit 107 is connected to the outlet air passage 106 so as to quickly reduce the outlet pressure of the second compressor 103 when the compressor in the compressor unit 10 experiences surge. The outlet end of the anti-surge circuit 107 is connected to the inlet air passage 1044 connected to the first compressor 102 so as to increase the flow rate at the gas inlet of the first compressor 102 when the compressor unit 10 experiences surge, thereby indirectly increasing the flow rate at each gas inlet of the second compressor 103, and ultimately achieving the purpose of suppressing the surge of the compressor unit 10.

[0039] Thus, the compressor unit 10 for an ammonia refrigeration system provided in this application embodiment drives the first compressor 102 and the second compressor 103 coaxially via a steam turbine 101, and incorporates an anti-surge circuit 107. This ensures that the compressor unit 10 has the function of mitigating surge while also saving on construction costs. Furthermore, the series connection of single-cylinder and multi-cylinder compressors optimizes the matching between compression stages. The first compressor 102 and the second compressor 103, as well as the different compression cylinders of the second compressor 103, are connected via a return gas path 105, ensuring smooth flow of ammonia between different compression stages. The anti-surge circuit 107 can rapidly reduce the outlet pressure and increase the inlet flow when surge occurs in the compressor unit 10, thereby improving the stability and safety of the compressor unit 10's operation.

[0040] In some embodiments, the intake circuit 1044 includes an intake passage 1041. The intake passage 1041 is connected to the first compressor 102, and the outlet of the anti-surge circuit 107 is connected to the intake passage 1041, so that low-temperature and low-pressure ammonia gas can enter the first compressor 102 through the intake passage 1041.

[0041] The intake circuit 1044 includes a first gas filling passage 1044. The first gas filling passage 1044 is connected to the second compressor 103. Low-temperature and low-pressure ammonia gas can be mixed with a first stage of compressed ammonia gas through the first gas filling passage 1044 to form a first stage of mixed ammonia gas, which then enters the second compressor 103. The second compressor 103 compresses the first stage of mixed ammonia gas to obtain a second stage of compressed ammonia gas.

[0042] The intake circuit 1044 includes a second gas filling passage 1045. The second gas filling passage 1045 is connected to the second compressor 103. Low-temperature, low-pressure ammonia gas can be mixed with the second-stage compressed ammonia gas through the second gas filling passage 1045 to form a two-stage mixed ammonia gas before entering the second compressor 103. The second compressor 103 can compress the two-stage mixed ammonia gas to obtain the target compressed ammonia gas.

[0043] Since the compressor unit 10 for the ammonia refrigeration system provided in this application embodiment can perform three-stage compression of ammonia, the intake circuit 1044 of the compressor unit 10 needs to include three intake air paths: a first intake air path 1041, a first gas filling air path 1044, and a second gas filling air path 1045. The first intake air path 1041 is connected to the first compressor 102, while the first gas filling air path 1044 and the second gas filling air path 1045 are respectively connected to the low-pressure cylinder and the high-pressure cylinder of the second compressor 103. Low-temperature, low-pressure ammonia enters the first compressor 102 through the first intake air path 1041, and the first compressor 102 compresses the low-temperature, low-pressure ammonia to obtain compressed ammonia. The low-temperature, low-pressure ammonia in the ammonia supply assembly flows into the first refueling path 1044. In the first refueling path 1044, a first stage of compressed ammonia mixes with the low-temperature, low-pressure ammonia to form a first stage of mixed ammonia, which then enters the low-pressure cylinder of the second compressor 103. The low-pressure cylinder of the second compressor 103 compresses the first stage of mixed ammonia to obtain a second stage of compressed ammonia. The low-temperature, low-pressure ammonia in the ammonia supply assembly can also flow into the second refueling path 1045, where it mixes with the second stage of compressed ammonia to form a second stage of mixed ammonia. The second stage of mixed ammonia finally flows into the high-pressure cylinder of the second compressor 103, where the second compressor 103 further compresses the second stage of mixed ammonia to obtain the target compressed ammonia.

[0044] In the above embodiments, through the coordinated operation of an intake air passage 1041, a first gas filling air passage 1044, and a second gas filling air passage 1045, the low-pressure cylinder of the first compressor 102 and the high-pressure cylinder of the second compressor 103 can sequentially complete a three-stage compression process. The intake circuit 1044 not only optimizes the matching of intake parameters before each compression stage, improving the compression efficiency of the compressor unit 10, but also replenishes the second compressor 103 with gas through the first gas filling air passage 1044 and the second gas filling air passage 1045, thereby reducing the single-stage compression load. Furthermore, the independent control capability of each gas filling air passage enhances the adaptability of the compressor unit 10 to different operating conditions, ensuring the stability of the pressure and flow rate of the target compressed ammonia gas, thereby improving the stability and flexibility of the entire compressor unit 10 operation.

[0045] In some embodiments, the return gas path 105 includes a first return gas path 1051. The inlet end of the first return gas path 1051 is connected to the first compressor 102, and the outlet end of the first return gas path 1051 is connected to the first gas filling path 1044. A section of compressed ammonia gas can enter the second compressor 103 through the first return gas path 1051.

[0046] The return gas path 105 includes a second return gas path 1053. The inlet end of the second return gas path 1053 is connected to the second compressor 103, and the outlet end of the second return gas path 1053 is connected to the second gas filling path 1045. The ammonia gas compressed in the second stage can re-enter the second compressor 103 through the second return gas path 1053.

[0047] Specifically, the first return gas path 1051 directs a portion of compressed gas from the first compressor 102 to the first filling gas path 1044, where the compressed ammonia mixes with the low-temperature, low-pressure ammonia in the first filling gas path 1044, ultimately forming a mixed ammonia. The low-pressure cylinder of the second compressor 103 compresses the mixed ammonia, resulting in a second-stage compressed ammonia. Similarly, the second return gas path 1053 directs the second-stage compressed ammonia generated in the low-pressure cylinder of the second compressor 103 to the second filling gas path 1045, where the compressed ammonia mixes with the low-temperature, low-pressure ammonia in the second filling gas path 1045, resulting in a second-stage mixed ammonia. The high-pressure cylinder of the second compressor 103 then compresses the second-stage mixed ammonia, ultimately yielding the target compressed ammonia.

[0048] Preferably, a first cooler 1052 can be installed on the first return gas path 1051 to cool a section of compressed ammonia gas in the first return gas path 1051, and a second cooler 1054 can be installed on the second return gas path 1053 to cool a second section of compressed ammonia gas in the second return gas path 1053, thereby preventing the ammonia gas temperature entering the second compressor 103 from being too high and causing mechanical failure of the compressor unit 10.

[0049] In the above embodiments, the first return gas path 1051 and the second return gas path 1053 can respectively transport the first-stage compressed ammonia and the second-stage compressed ammonia generated by the previous stage compression to the corresponding gas filling path, where they are fully mixed with the low-temperature, low-pressure ammonia before entering the next stage compression cylinder. This achieves smooth flow of ammonia between the low-pressure cylinder of the first compressor 102, the low-pressure cylinder of the second compressor 103, and the high-pressure cylinder of the second compressor 103, minimizing energy loss during interstage transmission of the compressed ammonia. Furthermore, the outlet of the return gas path 105 is directly connected to the gas filling path, simplifying the pipeline layout and further reducing the construction and operation / maintenance costs of the compressor unit 10.

[0050] In some embodiments, the first compressor 102 includes a first air inlet 1021. The first air inlet 1021 is connected to an air intake passage 1041.

[0051] The first compressor 102 includes a first air outlet 1022. The first air outlet 1022 is connected to the air inlet of the first return air passage 1051.

[0052] The first air inlet 1021 of the first compressor 102 is connected to the air outlet of a section of air intake passage 1041, and the first air outlet 1022 of the first compressor 102 is connected to the air inlet of the first return air passage 1051. After passing through the section of air intake passage 1041, the low-temperature and low-pressure ammonia gas can flow into the first compressor 102 through the first air inlet 1021. The compressed ammonia gas obtained after the first compressor 102 compresses the low-temperature and low-pressure ammonia gas can flow out of the first compressor 102 through the first air outlet 1022 and flow into the first gas filling passage 1044 through the first return air passage 1051, and finally enter the low-pressure cylinder of the second compressor 103.

[0053] In the above embodiment, low-temperature and low-pressure ammonia gas can flow into the first compressor 102 through the first inlet 1021, and the compressed ammonia gas is discharged through the first outlet 1022 to the first return gas path 1051, and then sent into the low-pressure cylinder of the second compressor 103. The independent setting of the inlet and outlet ensures that the intake and exhaust of the first compressor 102 are smooth and do not interfere with each other during continuous operation, which enhances the stability of the working process of the first compressor 102, and provides a reliable gas source interface for the mixing of ammonia gas in the first return gas path 1051 and the first gas filling path 1044, thereby further improving the operating efficiency and safety reliability of the entire compressor unit 10 in the three-stage compression process.

[0054] In some embodiments, an intake air passage 1041 includes an intake pipe 1042 and a gas return port 1043. The intake pipe 1042 is connected to the ammonia supply assembly and the first intake port 1021, and the gas return port 1043 is disposed in the intake pipe 1042 and is connected to the outlet end of the anti-surge circuit 107.

[0055] Specifically, the inlet end of an intake pipe 1042 is connected to an ammonia supply assembly, and the outlet end of an intake pipe 1042 is connected to the first inlet 1021 of the first compressor 102. A gas return port 1043 is also provided on the intake pipe 1042, which is connected to the outlet end of the anti-surge circuit 107, so that when the compressor unit 10 experiences surge, the target compressed ammonia can flow back into the intake pipe 1042 through the anti-surge circuit 107 and the gas return port 1043, and finally re-enter the first compressor 102.

[0056] In the above embodiment, by providing a gas return port 1043 connected to the outlet of the anti-surge circuit 107 on a section of the intake pipe 1042, the target compressed ammonia gas can be directly returned to the first compressor 102 when surge occurs in the compressor unit 10. This makes the anti-surge response path shorter and more efficient, achieving the goal of quickly returning the target compressed ammonia gas to the inlet of the first compressor 102. At the same time, it increases the inlet flow rate of the compressor unit 10, which can more effectively suppress the surge phenomenon of the compressor unit 10. The integrated design of the gas return port 1043 and the intake pipe avoids the need to add other pipelines, reduces the modification cost and maintenance difficulty, and ensures that low-temperature, low-pressure ammonia gas can be stably supplied to the first compressor 102 when the compressor unit 10 is under normal operating conditions. Thus, while ensuring the safe operation of the compressor unit 10, it improves the simplicity and economy of the compressor unit 10 structure.

[0057] In some embodiments, the second compressor 103 includes a second air inlet 1031, a second air outlet 1032, a third air inlet 1033, and a total air outlet 1034. The second air inlet 1031 is connected to the first gas filling passage 1044, the second air outlet 1032 is connected to the air inlet of the second return gas passage 1053, the third air inlet 1033 is connected to the second gas filling passage 1045, and the total air outlet 1034 is connected to the air outlet passage 106.

[0058] The low-pressure cylinder of the second compressor 103 has a second inlet 1031 and a second outlet 1032. A section of mixed ammonia gas in the first gas supply path 1044 can enter the low-pressure cylinder of the second compressor 103 through the second inlet 1031. After the low-pressure cylinder of the second compressor 103 compresses the section of mixed ammonia gas, it can obtain two-stage compressed ammonia gas. The two-stage compressed ammonia gas can flow out of the low-pressure cylinder of the second compressor 103 through the second outlet 1032, and then flow sequentially into the second return gas path 1053 and the second gas supply path 1045, and then combine with the ammonia gas supply assembly to supply the second The low-temperature, low-pressure ammonia gas supplied in the gas filling passage 1045 is mixed in the second gas filling passage 1045 to form a two-stage mixed ammonia gas. The two-stage mixed ammonia gas can flow from the second gas filling passage 1045 through the third air inlet 1033 into the high-pressure cylinder of the second compressor 103. The high-pressure cylinder of the second compressor 103 compresses the two-stage mixed ammonia gas to generate the target compressed ammonia gas. The target compressed ammonia gas can finally flow out of the high-pressure cylinder of the second compressor 103 through the total air outlet 1034, flow into the air outlet passage 106, and finally flow to the subsequent equipment in the ammonia refrigeration system.

[0059] In the above embodiment, by sequentially connecting the second air inlet 1031 with the first gas filling passage 1044, the second air outlet 1032 with the second return gas passage 1053, the third air inlet 1033 with the second gas filling passage 1045, and the total air outlet 1034 with the air outlet passage 106, independent air intake and exhaust of the low-pressure cylinder and the high-pressure cylinder and between the compressor unit 10 are achieved. This allows a first stage of mixed ammonia gas to smoothly enter the low-pressure cylinder of the second compressor 103 for compression. The second stage of compressed ammonia gas produced by the low-pressure cylinder of the second compressor 103 can be smoothly discharged and mixed with low-temperature and low-pressure ammonia gas before entering the high-pressure cylinder of the second compressor 103 for further compression. Finally, the target compressed ammonia gas can be stably output to subsequent equipment through the total air outlet 1034, avoiding interstage cross-flow and pressure interference, ensuring the continuity of the three-stage compression in the compressor unit 10 and the reasonable distribution of the compression ratio, thereby improving the compression efficiency of the compressor unit 10 and ensuring the stability of the compressor unit 10 during operation.

[0060] In some embodiments, the anti-surge circuit 107 includes a return pipe 1071 and an anti-surge valve 1072. The inlet end of the return pipe 1071 is connected to the outlet gas passage 106, and the outlet end of the return pipe 1071 is connected to a section of the inlet gas passage 1041. The anti-surge valve 1072 is disposed in the return pipe 1071. When the compressor unit 10 experiences surge, the anti-surge valve 1072 can open to allow the target compressed ammonia gas to flow through the return pipe 1071 to the section of the inlet gas passage 1041.

[0061] When compressor unit 10 experiences surge, the controller of compressor unit 10 can open the anti-surge valve 1072, allowing the target compressed ammonia gas in the outlet gas path 106 to flow into the return pipe 1071, thereby reducing the gas pressure at the total outlet of the second compressor 103 and alleviating the surge phenomenon of compressor unit 10. The target compressed ammonia gas flowing into the return pipe 1071 can then flow back into a section of the intake gas path 1041 through the gas return port 1043, thereby increasing the gas flow rate at the first intake port 1021 of the first compressor 102 and further alleviating the surge phenomenon of compressor unit 10.

[0062] In the above embodiment, the cooperation between the return pipe 1071 and the anti-surge valve 1072 enables the compressor unit 10 to quickly open the anti-surge valve 1072 when surge occurs, so as to guide the target compressed ammonia gas in the outlet gas path 106 back to a section of the inlet gas path 1041 through the return pipe 1071. Guiding the target compressed ammonia gas from the outlet gas path 106 back to a section of the inlet gas path 1041 can not only quickly reduce the outlet pressure of the second compressor 103, but also increase the inlet flow of the first compressor 102 by using the return gas. Surge is suppressed from both the outlet pressure and inlet flow of the compressor unit 10, thereby improving the surge suppression speed of the compressor unit 10. Furthermore, compared to the design in related technologies where the number of anti-surge circuits 107 and intake air paths are the same, the compressor unit 10 for an ammonia refrigeration system provided in this application embodiment has three intake air paths, but only one anti-surge circuit 107 is designed. This greatly simplifies the air path structure of the compressor unit 10 while ensuring stable operation, and at the same time reduces the construction and subsequent maintenance costs of the compressor unit 10. In some embodiments, the ammonia refrigeration system further includes a liquid ammonia supply assembly, and the anti-surge circuit 107 further includes a cooling pipeline 1073. The cooling pipeline 1073 is disposed between the liquid ammonia supply assembly and the return pipeline 1071, and is used to introduce liquid ammonia from the liquid ammonia supply assembly into the return pipeline 1071 to cool the target compressed ammonia gas in the return pipeline 1071.

[0063] The anti-surge circuit 107 also includes a temperature control valve 1074. The temperature control valve 1074 is installed on the cooling pipe 1073 and can open when the temperature in the return pipe 1071 reaches a predetermined temperature.

[0064] Since the target compressed ammonia gas entering the anti-surge circuit 107 directly from the outlet gas path 106 is high-temperature and high-pressure ammonia gas, there is still a risk of overheating when the target compressed ammonia gas mixes with low-temperature and low-pressure ammonia gas and enters the first compressor 102. If the ammonia gas temperature entering the first compressor 102 is too high, it may damage the internal structure of the compressor unit 10. In order to avoid mechanical failure of the compressor unit 10 due to the excessively high temperature of the ammonia gas entering the first compressor 102, a cooling pipe 1073 can be installed on the anti-surge circuit 107. The liquid inlet end of the cooling pipe 1073 is connected to the liquid ammonia supply component in the ammonia refrigeration system, and the liquid outlet end of the cooling pipe 1073 is connected to the return pipe 1071 between the anti-surge valve 1072 and the outlet end of the return pipe 1071, so that the cooling pipe can introduce liquid ammonia into the return pipe 1071 to cool and depressurize the target compressed ammonia gas in the return pipe 1071. A temperature control valve 1074 is installed on the cooling pipeline 1073. The temperature control valve 1074 can automatically open when the temperature of the target compressed ammonia gas in the return pipeline 1071 is higher than the predetermined temperature, so that liquid ammonia can flow into the return pipeline 1071, thereby reducing the temperature and pressure of the target compressed ammonia gas in the return pipeline 1071.

[0065] The above embodiment utilizes a temperature control valve 1074 to automatically open and close the cooling pipeline 1073. This allows for the introduction of low-temperature liquid ammonia from the liquid ammonia supply component into the return pipeline 1071 when the compressor unit 10 experiences surge and the temperature in the return pipeline 1071 becomes excessively high. This achieves timely cooling and depressurization of the high-temperature, high-pressure target compressed ammonia gas, effectively preventing the overheating risk that still exists after the high-temperature target compressed ammonia gas mixes with the low-temperature, low-pressure ammonia gas. It also avoids high-temperature gas entering the first compressor 102 and causing thermal damage or mechanical failure to internal components, thereby improving the operational safety of the compressor unit 10 under anti-surge conditions. Simultaneously, the automatic sensing control of the temperature control valve 1074 requires no manual intervention, ensuring timely cooling response and avoiding unnecessary consumption of liquid ammonia, thus improving the economy and reliability of the compressor unit 10.

[0066] In some embodiments, the compressor unit 10 further includes a first monitoring component 1081, a second monitoring component 1082, and a third monitoring component 1083. The first monitoring component 1081 is disposed in the intake circuit 1044, the second monitoring component 1082 is disposed in the return air passage 105, and the third monitoring component 1083 is disposed in the outlet air passage 106.

[0067] Specifically, the monitoring components include pressure monitoring elements, flow monitoring elements, and temperature monitoring elements. The pressure monitoring element can be a pressure sensor, the flow monitoring element can be a venturi, which can represent the gas flow data through the differential pressure value of the gas passing through both ends of a pipeline, and the temperature monitoring element can be a temperature sensor.

[0068] The first monitoring component 1081 includes a gas monitoring sub-component, a first refueling gas monitoring sub-component, and a second refueling gas monitoring sub-component. The gas monitoring sub-component is disposed on a first intake gas passage 1041, the first refueling gas monitoring sub-component is disposed on a first refueling gas passage 1044, and the second refueling gas monitoring sub-component is disposed on a second refueling gas passage 1045.

[0069] A gas monitoring sub-assembly includes a first pressure monitoring element, a first flow monitoring element, and a first temperature monitoring element. The first pressure monitoring element is disposed on a section of inlet pipe 1042, between the gas return port 1043 and the outlet of a section of inlet gas passage 1041. The first flow monitoring element is disposed between the first pressure monitoring element and the outlet of a section of inlet gas passage 1041. The first temperature monitoring element is disposed between the first flow monitoring element and the outlet of a section of inlet gas passage 1041.

[0070] The first gas refueling monitoring sub-assembly includes a second pressure monitoring element, a second flow monitoring element, and a second temperature monitoring element. The second pressure monitoring element is disposed on the pipeline between the connection between the first return gas path 1051 and the first refueling gas path 1044 and the outlet end of the first refueling gas path 1044. The second flow monitoring element is disposed on the pipeline between the second pressure monitoring element and the outlet end of the first refueling gas path 1044. The second temperature monitoring element is disposed on the pipeline between the second flow monitoring element and the outlet end of the first refueling gas path 1044.

[0071] The second gas refueling monitoring sub-assembly includes a third pressure monitoring element and a third temperature monitoring element. The third pressure monitoring element is installed in the pipeline between the connection point of the second return gas path 1053 and the second refueling gas path 1045 and the outlet end of the second refueling gas path 1045. The third temperature monitoring element is installed in the pipeline between the third pressure monitoring element and the outlet end of the second refueling gas path 1045. Specifically, since the flow rate of the two-stage mixed ammonia gas in the second refueling gas path 1045 is the same as the target compressed gas flow rate in the outlet gas path 106, only one flow monitoring element is installed in the outlet gas path 106, and no flow monitoring element is installed in the second refueling gas path 1045.

[0072] The second monitoring component 1082 includes a first-stage compressed gas monitoring sub-component and a second-stage compressed gas monitoring sub-component. The first-stage compressed gas monitoring sub-component is located in the first return gas path 1051, and the second-stage compressed gas monitoring sub-component is located in the second return gas path 1053. Further, the first-stage compressed gas monitoring sub-component is located between the inlet end of the first return gas path 1051 and the first cooler 1052, and the second-stage compressed gas monitoring sub-component is located between the inlet end of the second return gas path 1053 and the second cooler 1054.

[0073] A compressed gas monitoring sub-assembly includes a fourth pressure monitoring element and a fourth temperature monitoring element. The fourth pressure monitoring element is located between the inlet end of the first return gas passage 1051 and the first cooler 1052, and the fourth temperature monitoring element is located between the inlet end of the first return gas passage 1051 and the fourth pressure monitoring element.

[0074] The two-stage compressed gas monitoring sub-assembly includes a fifth pressure monitoring element and a fifth temperature monitoring element. The fifth pressure monitoring element is located between the inlet end of the second return gas passage 1053 and the second cooler 1054, and the fifth temperature monitoring element is located between the inlet end of the second return gas passage 1053 and the fifth pressure monitoring element.

[0075] The third monitoring component 1083 includes a sixth pressure monitoring element, a third flow rate monitoring element, and a sixth temperature monitoring element. The third monitoring component 1083 is located between the inlet end of the outlet gas path 106 and the connection point between the outlet gas path 106 and the return pipe 1071. The sixth temperature monitoring component is located between the inlet end of the outlet gas path 106 and the connection point between the outlet gas path 106 and the return pipe 1071. The third flow rate monitoring element is located between the inlet end of the outlet gas path 106 and the sixth temperature monitoring element. The sixth pressure monitoring component is located between the inlet end of the outlet gas path 106 and the third flow rate monitoring component.

[0076] The above embodiments, by setting gas monitoring components in the intake circuit 1044, return gas path 105, and outlet gas path 106 respectively, realize comprehensive and real-time acquisition of the status parameters of the first-stage intake ammonia, the first-stage compressed ammonia, the first-stage mixed ammonia, the second-stage compressed ammonia, the second-stage mixed ammonia, and the target compressed ammonia in the entire working process of the compressor unit 10. This provides a solid and reliable basis for the operation status assessment, surge prevention and control of the compressor unit 10, and lays a solid foundation for the safe and stable operation and intelligent control of the compressor unit 10.

[0077] This application also provides an anti-surge control method, which is applied to the compressor unit 10 for an ammonia refrigeration system provided in any of the above embodiments. Therefore, the executing entity of this anti-surge control method can be the controller of the compressor unit 10 for the ammonia refrigeration system. Please refer to... Figure 4 The anti-surge control method can be implemented through steps 401 to 404: Step 401: The controller generates a first surge curve and a second surge curve based on the expected performance of the first compressor 102 and the second compressor 103 and historical surge data, respectively. The controller deviates the first surge curve and the second surge curve from the first direction by a first distance, respectively, to obtain a first anti-surge curve and a second anti-surge curve.

[0078] The first surge curve and the second surge curve are plotted from the critical points when the first compressor 102 and the second compressor 103 experience surge during operation. The controller generates the first surge curve and the second surge curve based on the expected performance and historical surge data of the first compressor 102 and the expected performance and historical surge data of the second compressor 103, respectively. That is, the surge curve of the first compressor 102 is the first surge curve, and the surge curve of the second compressor 103 is the second surge curve. The historical surge data of the first compressor 102 includes the first historical intake data at the first intake port 1021 and the first historical exhaust data at the first exhaust port 1023 when the first compressor 102 experiences surge. The historical surge data of the second compressor 103 includes the second historical intake data at the second intake port 1031 and the target historical gas data at the total exhaust port 1034 when the second compressor 103 experiences surge. The first historical intake data includes the first historical intake pressure and the first historical intake flow rate; the first historical exhaust data includes the first historical exhaust pressure; the second historical intake data includes the second historical intake pressure and the second historical intake flow rate; and the target historical exhaust data includes the target historical exhaust pressure and the target historical exhaust flow rate.

[0079] The abscissa of each first surge point on the first surge curve is the ratio of the first historical outlet pressure to the first historical inlet pressure. The abscissa of the first surge curve is a dimensionless number calculated using a preset formula along with the first historical inlet flow rate, the first historical inlet pressure, and the first historical outlet pressure. Similarly, the abscissa of each third surge point on the third surge curve is the ratio of the target historical outlet pressure to the third historical inlet pressure. The abscissa of the third surge curve is a dimensionless number calculated using a preset formula along with the third historical inlet pressure, the target historical outlet pressure, and the target historical outlet flow rate.

[0080] The controller shifts the first surge curve and the second surge curve by a first distance along the positive direction of the horizontal axis, thereby obtaining the first anti-surge curve and the second anti-surge curve. The magnitude of the first distance can be determined based on the performance of the compressor unit 10 itself.

[0081] Specifically, the controller keeps the ordinates of each surge point on the first surge curve and the second surge curve unchanged, directly using them as the ordinates of each anti-surge point on the first anti-surge curve and the second anti-surge curve. The controller increases the abscissas of each surge point on the first surge curve and the second surge curve by a first preset threshold, and uses the increased abscissas as the abscissas of each anti-surge point. Based on the abscissas and ordinates of each anti-surge point, the controller plots the first anti-surge curve and the second anti-surge curve in the coordinate system on which the first surge curve and the second surge curve are plotted.

[0082] Step 402: The controller acquires the first intake data at the first intake port 1021, the first exhaust data at the first exhaust port 1023, the second intake data at the second intake port 1031, and the target gas data at the total exhaust port 1034.

[0083] A first intake data monitoring component is installed before the first intake port 1021 of the compressor unit 10. The first intake data monitoring component is used to acquire the first intake data of a section of ammonia gas entering the first compressor 102 and send the first intake data to the controller. A first outlet data monitoring component is installed after the first outlet port 1023. The first outlet data monitoring component is used to acquire the first outlet data of the first compressed ammonia gas formed by the first compressor 102 and flowing out of the first outlet port 1023, and send the first outlet data to the controller. A second intake data monitoring component is installed after the first outlet data monitoring component of the compressor unit 10 and before the second intake port 1031. The second intake data monitoring component is used to acquire the second intake data of the second mixed ammonia gas entering the second compressor 103 and send the second intake data to the controller. A target gas data monitoring component is installed after the total outlet port 1034. The target gas data monitoring component is used to acquire the target gas data of the third compressed ammonia gas formed by the second compressor 103 and flowing out of the total outlet port 1034, and send the target gas data to the controller.

[0084] Step 403: The controller determines the first actual operating point based on the first intake data and the first exhaust data, and controls the anti-surge valve 1072 to open based on the positional relationship between the first actual operating point and the first anti-surge curve satisfying the first preset condition.

[0085] The first preset condition is: the first operating point is located on the first anti-surge curve, or the first operating point is located between the first surge curve and the first anti-surge curve.

[0086] The controller calculates the first compression ratio of the first compressor 102 based on the first intake pressure and the first outlet pressure, and then determines the first operating point of the first compressor 102 based on the first compression ratio and the first intake flow rate. In the coordinate system, the area on the side of the first anti-surge curve that deviates from the first surge curve is defined as the first safe zone, the area between the first anti-surge curve and the first surge curve is defined as the first circulation zone, and the area on the side of the first surge curve that deviates from the first anti-surge curve is defined as the first surge zone. When the first operating point is on the first anti-surge curve or between the first surge curve and the first anti-surge curve, that is, when the first operating point is in the first circulation zone, it indicates that the first compressor 102 is at risk of surge. Therefore, the controller immediately controls the anti-surge valve 1072 to open to reduce the risk of surge in the first compressor 102.

[0087] Furthermore, while implementing step 403, the controller can also implement step 404: Step 404: The controller determines the second actual operating point based on the second intake data and the target gas data, and controls the anti-surge valve 1072 to open based on the second actual operating point and the second anti-surge curve meeting the second preset condition.

[0088] The second preset condition is: the second operating point is located on the second anti-surge curve, or the second operating point is located between the second surge curve and the second anti-surge curve.

[0089] The controller calculates the second compression ratio of the second compressor 103 based on the second intake pressure and the target outlet pressure, and then determines the second operating point of the second compressor 103 based on the second compression ratio and the second intake flow rate. In the coordinate system, the area on the side of the second anti-surge curve that deviates from the second surge curve is defined as the second safe zone, the area between the second anti-surge curve and the second surge curve is defined as the second circulation zone, and the area on the side of the second surge curve that deviates from the second anti-surge curve is defined as the second surge zone. When the second operating point is on the second anti-surge curve or between the second surge curve and the second anti-surge curve, that is, when the second operating point is in the second circulation zone, it indicates that the second compressor 103 is at risk of surge. Therefore, the controller immediately controls the anti-surge valve 1072 to open to reduce the risk of surge in the second compressor 103.

[0090] Furthermore, after steps 403 and 404, the controller can also perform steps 405 to 406: Step 405: The controller shifts the first surge curve and the second surge curve in the first direction by a second distance to obtain the first fast opening line and the second fast opening line, wherein the first distance is greater than the second distance.

[0091] Specifically, the controller keeps the ordinates of each surge point on the first and second surge curves unchanged and directly uses them as the ordinates of each fast-opening point on the first and second fast-opening lines. The controller increases the abscissas of each surge point on the first and second surge curves by a second preset threshold, and uses the increased abscissas as the abscissas of each fast-opening point. Based on the abscissas and ordinates of each fast-opening point, the controller draws the first and second fast-opening lines in the coordinate system on which the first and second surge curves are plotted.

[0092] Step 406: Based on the positional relationship between the first operating point and the first fast-opening line, the controller controls the anti-surge valve 1072 to open to the maximum degree.

[0093] The first preset full-open condition is: the first operating point is located on the first fast-opening line, or the first operating point is located between the first surge curve and the first fast-opening line.

[0094] While implementing step 406, the controller can also implement step 407: Step 407: Based on the positional relationship between the second operating point and the second fast-opening line, the controller controls the anti-surge valve 1072 to open to the maximum degree.

[0095] The second preset full-open condition is: the second operating point is located on the second fast-opening line, or the second operating point is located between the second surge curve and the second fast-opening line.

[0096] The controller compares the positional relationship between the first working point and the first fast-opening line, and the positional relationship between the second working point and the second fast-opening line. When the positional relationship between the first working point and the first fast-opening line meets the first preset full-opening condition, and / or the positional relationship between the second working point and the second fast-opening line meets the second preset full-opening condition, the controller immediately outputs a valve full-opening command to the anti-surge valve 1072 to control the anti-surge valve 1072 to open to the maximum degree.

[0097] Thus, the anti-surge control method provided in this application constructs personalized surge curves and anti-surge curves for the two-stage compressor units 10 of the ammonia refrigeration system based on historical surge data and expected performance, respectively. Based on the positional relationship between the compressor's operating point and the anti-surge curve, the anti-surge valve 1072 is opened in a timely manner to actively avoid surge. Furthermore, when the compressor's operating point approaches the surge zone, the valve is fully opened via a quick-opening line, rapidly releasing pressure and forcibly increasing the flow rate, thereby providing emergency protection for the compressor unit 10. Ultimately, while ensuring the safe operation of the unit, frequent or excessive operation of the anti-surge valve 1072 is avoided, improving the stability, response speed, and economy of the ammonia refrigeration system. This application also provides an ammonia refrigeration system, which includes the compressor unit 10, liquid ammonia supply component, and ammonia gas supply component provided in any of the above embodiments. The liquid ammonia supply component is connected to the compressor unit 10, and the ammonia gas supply component is also connected to the compressor unit 10. The ammonia refrigeration system provided in this application has the advantages of any of the above embodiments of the compressor unit 10 for the ammonia refrigeration system, which will not be described in detail here.

[0098] The anti-surge control device provided in this application embodiment can realize the various processes implemented in the above-described anti-surge control method embodiment. To avoid repetition, it will not be described again here.

[0099] This application also provides an electronic device, which includes a processor and a memory. The memory stores a program or instructions that can run on the processor. When the program or instructions are executed by the processor, they implement the various steps of the above-described anti-surge control method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0100] Memory can be used to store software programs and various data. Memory can primarily include a first storage area for storing programs or instructions and a second storage area for storing data. The first storage area can store the operating system, application programs or instructions required for at least one function (such as sound playback, image playback, etc.). Furthermore, memory can include volatile memory or non-volatile memory, or both. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM), static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (Synchlink DRAM, SLDRAM), and direct memory bus RAM (DRRAM). The memory in the embodiments of this application includes, but is not limited to, these and any other suitable types of memory.

[0101] The processor may include one or more processing units; optionally, the processor integrates an application processor and a modem processor, wherein the application processor mainly handles operations related to the operating system, user interface, and applications, while the modem processor mainly handles wireless communication signals, such as a baseband processor. It is understood that the aforementioned modem processor may also not be integrated into the processor.

[0102] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described anti-surge control method embodiments and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0103] This application also provides a chip, which includes a processor and a communication interface. The communication interface and the processor are coupled. The processor is used to run programs or instructions to implement the various processes of the above-described anti-surge control method embodiments and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0104] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0105] This application also provides a computer program product, which is stored in a storage medium and executed by at least one processor to implement the various processes of the above-described anti-surge control method embodiments, and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A compressor unit applied to an ammonia refrigeration system, characterized in that, The ammonia refrigeration system includes an ammonia supply component, which is capable of outputting low-temperature, low-pressure ammonia gas. The compressor unit includes: Steam turbine; The first compressor is coaxially arranged with the steam turbine so that the steam turbine can drive the first compressor to work. The first compressor can compress the low-temperature and low-pressure ammonia gas to form a section of compressed ammonia gas. The second compressor is located on the side of the first compressor away from the steam turbine. The second compressor is coaxially connected to the steam turbine so that the steam turbine can drive the second compressor to work. The second compressor can compress the first-stage compressed ammonia and the low-temperature, low-pressure ammonia to finally obtain the target compressed ammonia. An air intake circuit is provided between the ammonia supply component and the first compressor, and between the ammonia supply component and the second compressor; A return air path is provided between the first compressor and the intake circuit, and between the second compressor and the intake circuit; The exhaust gas path is connected to the second compressor; An anti-surge circuit, wherein the air inlet of the anti-surge circuit is connected to the air outlet, and the air outlet of the anti-surge circuit is connected to the air inlet circuit.

2. The compressor unit applied to an ammonia refrigeration system according to claim 1, characterized in that, The intake circuit includes: An intake air passage is connected to the first compressor, and the outlet of the anti-surge circuit is connected to the intake air passage. The low-temperature, low-pressure ammonia gas can enter the first compressor through the intake air passage. The first gas filling path is connected to the second compressor. The low-temperature and low-pressure ammonia gas can be mixed with the first stage of compressed ammonia gas through the first gas filling path to form a first stage of mixed ammonia gas, which then enters the second compressor. The second compressor compresses the first stage of mixed ammonia gas to obtain a second stage of compressed ammonia gas. The second gas filling path is connected to the second compressor. The low-temperature, low-pressure ammonia gas can be mixed with the two-stage compressed ammonia gas through the second gas filling path to form a two-stage mixed ammonia gas before entering the second compressor. The second compressor can compress the two-stage mixed ammonia gas to obtain the target compressed ammonia gas.

3. The compressor unit applied to an ammonia refrigeration system according to claim 2, characterized in that, The return gas path includes: The first return gas path has an inlet end connected to the first compressor and an outlet end connected to the first gas filling path. The compressed ammonia gas can enter the second compressor through the first return gas path. The second return gas path has an inlet end connected to the second compressor and an outlet end connected to the second gas filling path. The two-stage compressed ammonia gas can re-enter the second compressor through the second return gas path.

4. The compressor unit applied to an ammonia refrigeration system according to claim 3, characterized in that, The intake air passage includes: An intake pipe is connected to the ammonia supply assembly and the first intake port; A gas return port is provided in the section of the air inlet pipe, and the gas return port is connected to the air outlet of the anti-surge circuit.

5. The compressor unit applied to an ammonia refrigeration system according to claim 4, characterized in that, The second compressor includes: The second air inlet is connected to the first refueling air passage; The second air outlet is connected to the air inlet of the second return air path; The third air inlet is connected to the second refueling air passage; The main air outlet is connected to the air outlet path.

6. The compressor unit applied to an ammonia refrigeration system according to claim 2, characterized in that, The anti-surge circuit includes: A return pipe, wherein the air inlet end of the return pipe is connected to the air outlet path, and the air outlet end of the return pipe is connected to the section of the air inlet path; An anti-surge valve is installed in the return pipe. When the compressor unit experiences surge, the anti-surge valve can open to allow the target compressed ammonia gas to flow through the return pipe to the first section of the intake air path.

7. The compressor unit applied to an ammonia refrigeration system according to claim 6, characterized in that, The ammonia refrigeration system also includes a liquid ammonia supply component, and the anti-surge circuit also includes: A cooling pipeline is provided between the liquid ammonia supply component and the return pipeline. The cooling pipeline is used to introduce liquid ammonia from the liquid ammonia supply component into the return pipeline to cool the target compressed ammonia gas in the return pipeline. A temperature control valve is installed on the cooling pipeline. The temperature control valve can open when the temperature in the return pipeline reaches a predetermined temperature.

8. The compressor unit for an ammonia refrigeration system according to any one of claims 1 to 7, characterized in that, The compressor unit also includes: A first monitoring component is installed in the air intake circuit; The second monitoring component is installed in the return gas path; The third monitoring component is located in the outlet gas path.

9. A surge control method, characterized in that, The anti-surge control method, applied to a compressor unit for an ammonia refrigeration system as described in any one of claims 1 to 8, comprises: A first surge curve and a second surge curve are generated based on the expected performance of the first compressor and the second compressor and historical surge data, respectively. The first surge curve and the second surge curve are deviated from the first direction by a first distance, respectively, to obtain a first anti-surge curve and a second anti-surge curve. Acquire the first intake data at the first intake port, the first exhaust data at the first outlet, the second intake data at the second intake port, and the target gas data at the total outlet. Based on the first intake data and the first exhaust data, a first actual operating point is determined, and based on the positional relationship between the first actual operating point and the first anti-surge curve satisfying a first preset condition, the anti-surge valve is controlled to open; and / or Based on the second intake data and the target gas data, a second actual operating point is determined, and based on the second actual operating point and the second anti-surge curve, the positional relationship between the second actual operating point and the second anti-surge curve satisfies a second preset condition, the anti-surge valve is controlled to open.

10. An ammonia refrigeration system, characterized in that, include: Compressor unit for an ammonia refrigeration system as described in any one of claims 1 to 8 above; A liquid ammonia supply assembly is connected to the compressor unit; The ammonia supply component is connected to the compressor unit.

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