Anti-surge system for a refrigeration station and compressor group

Abstract

The embodiment of the present application discloses an anti-surge system for a refrigeration station and a compressor unit, the anti-surge system comprising: a centrifugal compressor comprising a gas outlet; a first gas path for receiving a section of gas, the section of gas being compressed by the centrifugal compressor to form first compressed gas; a second gas path for receiving first supplementary gas, the first supplementary gas being mixed with the first compressed gas and compressed by the centrifugal compressor to form second compressed gas; a third gas path for receiving second supplementary gas, the second supplementary gas being mixed with the second compressed gas and compressed by the centrifugal compressor to form third compressed gas; an exhaust gas path connected to the gas outlet, the exhaust gas path being used for discharging the third compressed gas from the anti-surge system; and an anti-surge gas path selectively connected to the first gas path, the second gas path and the third gas path, the anti-surge gas path being used for feeding the first compressed gas into the first gas path, or feeding the second compressed gas into the second gas path, or feeding the third compressed gas into the third gas path.

Description

Technical Field

[0001] This application relates to the field of compressors, and more particularly to an anti-surge system and compressor unit for refrigeration plants. Background Technology

[0002] A chiller plant is a centralized refrigeration system whose main task is to produce chilled water or other refrigerants and transport them through pipelines to various terminal devices that require cooling, thus meeting the needs of building comfort cooling or industrial production cooling. A chiller plant contains a compressor that compresses refrigerant gas and drives its circulation within the plant. However, in practice, the compressor may experience surge due to insufficient inlet flow or excessive outlet pressure, which can prevent it from operating normally. Summary of the Invention

[0003] This application discloses an anti-surge system and compressor unit for a refrigeration plant. By setting an anti-surge circuit, the problem of compressor surge caused by insufficient intake flow or excessive outlet pressure is solved.

[0004] To achieve the above objectives, in a first aspect, embodiments of this application disclose an anti-surge system for a refrigeration plant, the anti-surge system comprising: Centrifugal compressor, including the air outlet; The first gas path includes a first inlet for receiving a section of gas. The first gas path is connected to the centrifugal compressor. The section of gas enters the centrifugal compressor through the first gas path to form a first compressed gas. The second gas path is connected to the centrifugal compressor. The second gas path includes a second inlet for receiving the first supplementary gas. After the first supplementary gas enters the centrifugal compressor through the second gas path, it mixes with the first compressed gas and is compressed by the centrifugal compressor to form the second compressed gas. The third gas path is connected to the centrifugal compressor. The third gas path includes a third inlet for receiving the second supplementary gas. After the second supplementary gas enters the centrifugal compressor through the third gas path, it mixes with the second compressed gas and is compressed by the centrifugal compressor to form the third compressed gas. An exhaust gas path is connected to the air outlet, and the exhaust gas path is used to discharge the third compressed gas from the anti-surge system; An anti-surge air passage is connected to the exhaust air passage. The anti-surge air passage can be selectively connected to the first air passage, the second air passage, and the third air passage. The anti-surge air passage is used to send the first compressed gas into the first air passage, or the second compressed gas into the second air passage, or the third compressed gas into the third air passage.

[0005] In one possible implementation, the anti-surge air path includes: The first branch is connected to the exhaust gas path, and the first branch is equipped with a first valve. The first branch and the first gas path are selectively connected through the first valve. The second branch is connected to the exhaust gas path. The second branch is equipped with a second valve, and the second branch and the second gas path can be selectively connected through the second valve. The third branch is connected to the exhaust gas path, and the third branch is equipped with a third valve. The third branch is selectively connected to the second gas path through the third valve.

[0006] In one possible implementation, the first gas path includes: The first pipeline is connected to the first air inlet and is connected to the centrifugal compressor. A first intake valve is installed in the first pipeline, and the gas in a certain section is controlled to enter the centrifugal compressor by opening the first intake valve. A first sensing element group is disposed in the first pipeline. The first sensing element group is capable of acquiring first gas data about the gas segment, wherein the first gas data includes: first temperature data, first pressure data, and first flow rate data.

[0007] In one possible implementation, the second gas path includes: The second pipeline is connected to the second air inlet and is connected to the centrifugal compressor. The second intake valve is located in the second pipeline. By opening the second intake valve, the first supplementary gas is controlled to enter the centrifugal compressor. The second sensing element group is disposed in the second pipeline. The second sensing element group is capable of acquiring second gas data about the first supplementary gas, wherein the second gas data includes: second temperature data, second pressure data, and second flow rate data.

[0008] In one possible implementation, the third gas path includes: The third pipeline is connected to the third air inlet and is connected to the centrifugal compressor; The third intake valve is located in the third pipeline. By opening the third intake valve, the second supplementary gas is controlled to enter the centrifugal compressor. A third sensing element group is disposed in the third pipeline. The third sensing element group is capable of acquiring third gas data regarding the second supplementary gas, wherein the third gas data includes third temperature data and third pressure data.

[0009] In one possible implementation, the exhaust path includes: The air distribution pipeline is located between the air outlet and the anti-surge air path; An exhaust pipe is connected to the gas distribution pipe and is arranged in parallel with the anti-surge gas path, and the third compressed gas can be discharged from the anti-surge system through the exhaust pipe; A fourth sensing element group is disposed in the gas distribution pipeline. The fourth sensing element group is capable of acquiring fourth gas data about the third compressed gas, wherein the fourth gas data includes: fourth temperature data, fourth pressure data, and fourth flow rate data.

[0010] In one possible implementation, the gas distribution pipeline includes: A cooler is disposed in the gas distribution line, and the cooler is disposed away from the centrifugal compressor compared to the fourth sensing element group.

[0011] In one possible implementation, the anti-surge system further includes: The controller is communicatively connected to the centrifugal compressor, the first intake valve, the second intake valve, and the third intake valve. The controller can control the opening of the first intake valve, the second intake valve, or the third intake valve based on the operating state of the centrifugal compressor.

[0012] In one possible implementation, the controller is also communicatively connected to the first sensing element group, the second sensing element group, the third sensing element group, the fourth sensing element group, the first valve, the second valve, and the third valve, and the controller is also capable of: Acquire the first gas data, the second gas data, the third gas data, and the fourth gas data; When the centrifugal compressor generates the first compressed gas, a surge occurs. The first valve is controlled to open so that the first branch is connected to the first gas path. The opening and closing degree of the first valve is controlled based on the first gas data and the second gas data. When the centrifugal compressor generates the second compressed gas, a surge occurs, and the second valve is controlled to open so that the second branch is connected to the second gas path. The opening and closing degree of the second valve is controlled based on the first gas data, the second gas data, and the third gas data. When the centrifugal compressor generates the third compressed gas, a surge occurs, and the third valve is controlled to open so that the third branch is connected to the third gas path. The opening and closing degree of the third valve is controlled based on the first gas data, the second gas data, the third gas data, and the fourth gas data.

[0013] Secondly, embodiments of this application provide a compressor unit for a refrigeration plant, comprising: Anti-surge system for refrigeration plants as described in any one of the first aspects above.

[0014] By setting an anti-surge air path that can be selectively connected to the first, second, and third air paths, graded control can be performed according to the different locations where surge occurs. When the centrifugal compressor is running stably, the anti-surge air path is not connected to the first, second, and third air paths, and the gas is discharged from the centrifugal compressor after being compressed step by step along the normal path. When surge occurs, the anti-surge system performs corresponding recirculation operations based on the surge location: if surge occurs in the first compression stage, the anti-surge gas path is connected to the first gas path, allowing exhaust gas to flow back to the first inlet, increasing the intake flow rate of a section of gas and reducing the outlet pressure of the first compression chamber in the centrifugal compressor; if surge occurs in the second compression stage, the anti-surge gas path is connected to the second gas path, allowing exhaust gas to bypass the first compression chamber and directly replenish the second inlet, rapidly increasing the inlet flow rate of the second compression chamber in the centrifugal compressor and reducing the outlet pressure of the second compression chamber in the centrifugal compressor; if surge occurs in the third compression stage, the anti-surge gas path is connected to the third gas path, allowing exhaust gas to flow back to the third inlet, thereby rapidly increasing the inlet flow rate of the third compression chamber in the centrifugal compressor and reducing the outlet pressure of the third compression chamber in the centrifugal compressor. In this embodiment, the anti-surge gas path can be selectively connected to the intake gas path of each compression stage, allowing the recirculated gas to reach the compression stage experiencing surge via the shortest path, reducing the delay caused by the recirculated gas traveling through other compression stages, and also reducing interference with the normal operation of other compression stages. This design allows for more direct regulation of flow fluctuations in each compression stage when the centrifugal compressor is operating under varying load conditions, thereby improving the operational stability of the centrifugal compressor.

[0015] 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

[0016] 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.

[0017] Figure 1 This is one of the structural schematic diagrams of an anti-surge system provided in an embodiment of this application; Figure 2 This is a second schematic diagram of the structure of an anti-surge system provided in an embodiment of this application; Figure 3 This is the third structural schematic diagram of an anti-surge system provided in an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures: 10-Anti-surge system, 101-Centrifugal compressor, 1011-Outlet, 102-First air path, 1021-First air inlet, 1022-First pipeline, 1023-First intake valve, 1024-First sensor group, 103-Second air path, 1031-Second air inlet, 1032-Second pipeline, 1033-Second intake valve, 1034-Second sensor group, 104-Third air path, 1041-Third air inlet 1042-Third pipeline, 1043-Third intake valve, 1044-Third sensor element group, 105-Exhaust air path, 1051-Distribution air pipeline, 1052-Cooler, 1053-Exhaust pipeline, 1054-Fourth sensor element group, 106-Anti-surge air path, 1061-First branch, 1062-First valve, 1063-Second branch, 1064-Second valve, 1065-Third branch, 1066-Third valve. Detailed Implementation

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] This application provides an anti-surge system 10 for a refrigeration plant. The anti-surge system 10 includes a centrifugal compressor 101, which includes an outlet 1011. The centrifugal compressor 101 is capable of compressing gases. In this application embodiment, gases such as ammonia, carbon dioxide, and propane can be selected as refrigerants in the refrigeration plant. The centrifugal compressor can be a single-cylinder multi-stage compressor or a multi-cylinder compressor.

[0025] The anti-surge system 10 includes a first air passage 102. The first air passage 102 includes a first air inlet 1021 for receiving a section of gas. The first air passage 102 is connected to a centrifugal compressor 101, and a section of gas enters the centrifugal compressor 101 through the first air passage 102 to form a first compressed gas.

[0026] The anti-surge system 10 includes a second air passage 103. The second air passage 103 is connected to the centrifugal compressor 101. The second air passage 103 includes a second air inlet 1031 for receiving a first supplementary gas. After the first supplementary gas enters the centrifugal compressor 101 through the second air passage 103, it mixes with the first compressed gas and is compressed by the centrifugal compressor 101 to form a second compressed gas.

[0027] The anti-surge system 10 includes a third air passage 104. The third air passage 104 is connected to the centrifugal compressor 101. The third air passage 104 includes a third air inlet 1041 for receiving the second supplementary gas. After the second supplementary gas enters the centrifugal compressor 101 through the third air passage 104, it mixes with the second compressed gas and is compressed by the centrifugal compressor 101 to form the third compressed gas.

[0028] The anti-surge system 10 includes an exhaust air passage 105. The exhaust air passage 105 is connected to the air outlet 1011 and is used to discharge the third compressed gas from the anti-surge system 10.

[0029] The anti-surge system 10 includes an anti-surge air passage 106. The anti-surge air passage 106 is connected to the exhaust air passage 105. The anti-surge air passage 106 can be selectively connected to a first air passage 102, a second air passage 103, and a third air passage 104. The anti-surge air passage 106 is used to send a first compressed gas into the first air passage 102, a second compressed gas into the second air passage 103, or a third compressed gas into the third air passage 104.

[0030] Specifically, in this embodiment, the operation of the centrifugal compressor 101 is as follows: A segment of gas enters the centrifugal compressor 101 through the first air inlet 1021 and the first air passage 102. After the centrifugal compressor 101 performs a first compression stage on the segment of gas and obtains a first compressed gas, a first supplementary gas enters the centrifugal compressor 101 through the second air inlet 1031 and the second air passage 103. The first supplementary gas and the first compressed gas mix in the centrifugal compressor 101 to form a first mixed gas. The centrifugal compressor 101 performs a second compression stage on the first mixed gas to form a second compressed gas. Then, the second supplementary gas enters the centrifugal compressor 101 through the third air inlet 1041 and the third air passage 104. The second supplementary gas mixes with the second compressed gas in the centrifugal compressor 101 to form a second mixed gas. The centrifugal compressor 101 then performs a third compression stage on the second mixed gas to obtain a third compressed gas. The third compressed gas enters the exhaust gas passage 105 through the outlet 1011 of the centrifugal compressor 101 and finally flows to the downstream equipment. It can be seen that the centrifugal compressor 101 has a three-stage gas compression process. Surge may occur in each stage of gas compression. Therefore, an anti-surge circuit is provided in the anti-surge system 10. The anti-surge circuit can be selectively connected to the first air passage 102, the second air passage 103, and the third air passage 104 used for air intake.

[0031] When the centrifugal compressor is a single-cylinder multi-stage compressor, since the centrifugal compressor has only one compression cylinder, the first compression stage, the second compression stage, and the third compression stage all occur in the same compression chamber. At this time, the first air passage, the second air passage, and the third air passage are all connected to the same compression chamber. However, when the centrifugal compressor is a multi-cylinder compressor, the first compression stage, the second compression stage, and the third compression stage all occur in different compression chambers. At this time, the first air passage, the second air passage, and the third air passage are connected to different compression chambers to accurately replenish the compression chambers of different compression stages.

[0032] like Figure 1As shown, when the centrifugal compressor 101 does not experience surge, the anti-surge air path 106 is not connected to the first air path 102, the second air path 103, or the third air path 104. When the centrifugal compressor 101 experiences surge during the first compression stage of a gas segment, the anti-surge circuit is connected to the first air path 102 to reduce the pressure in the compression chamber of the centrifugal compressor 101 and allow the gas in the compression chamber to flow back to the first air path 102 through the anti-surge air path 106 to increase the flow rate of the gas segment. When the centrifugal compressor 101 experiences surge during the second compression stage of the first mixed gas... If surge occurs, the anti-surge circuit is connected to the second gas path 103 to reduce the pressure in the compression chamber of the centrifugal compressor 101 and allow the gas in the compression chamber to flow back to the second gas path 103 through the anti-surge gas path 106 to increase the flow rate of the first supplementary gas. If surge occurs when the centrifugal compressor 101 is in the third compression stage of the second mixed gas, the anti-surge circuit is connected to the third gas path 104 to reduce the pressure in the compression chamber of the centrifugal compressor 101 and allow the gas in the compression chamber to flow back to the third gas path 104 through the anti-surge gas path 106 to increase the flow rate of the second supplementary gas.

[0033] By setting an anti-surge air passage 106 that can be selectively connected to the first air passage 102, the second air passage 103, and the third air passage 104, graded control can be performed according to the different locations where surge occurs. When the centrifugal compressor 101 is running stably, the anti-surge air passage 106 is not connected to the first air passage 102, the second air passage 103, and the third air passage 104, and the gas is discharged from the centrifugal compressor 101 after being compressed step by step along the normal path. When surge occurs, the anti-surge system 10 performs corresponding backflow operations according to the surge location: if surge occurs in the first compression stage, the anti-surge air passage 106 is connected to the first air passage 102, allowing the exhaust gas to flow back to the first air inlet 1021, increasing the intake flow rate of a section of gas and reducing the outlet pressure of the first compression chamber in the centrifugal compressor 101; if surge occurs in the second compression stage, the anti-surge air passage 106 is connected to the second air passage 103, allowing the exhaust gas to bypass the first compression chamber and directly supplement the second air inlet 1031, rapidly increasing the inlet flow rate of the second compression chamber in the centrifugal compressor 101 and reducing the outlet pressure of the second compression chamber in the centrifugal compressor 101; if surge occurs in the third compression stage, the anti-surge air passage 106 is connected to the third air passage 104, allowing the exhaust gas to flow back to the third air inlet 1041, thereby rapidly increasing the inlet flow rate of the third compression chamber in the centrifugal compressor 101 and reducing the outlet pressure of the third compression chamber in the centrifugal compressor 101. In this embodiment, the anti-surge air passage 106 is selectively connected to the intake air passages of each compression stage, allowing the return gas to reach the compression stage experiencing surge via the shortest path. This reduces the delay caused by the return gas traveling through other compression stages and also minimizes interference with the normal operation of other compression stages. This design enables more direct regulation of flow fluctuations in each compression stage when the centrifugal compressor 101 operates under variable load conditions, thereby improving the operational stability of the centrifugal compressor 101.

[0034] In some embodiments, the anti-surge air passage 106 includes a first branch 1061. The first branch 1061 is connected to the exhaust air passage 105, and the first branch 1061 is provided with a first valve 1062. The first branch 1061 and the first air passage 102 are selectively connected through the first valve 1062.

[0035] The anti-surge air passage 106 includes a second branch 1063. The second branch 1063 is connected to the exhaust air passage 105. The second branch 1063 is equipped with a second valve 1064. The second branch 1063 and the second air passage 103 can be selectively connected through the second valve 1064.

[0036] The anti-surge air passage 106 includes a third branch passage 1065. The third branch passage 1065 is connected to the exhaust air passage 105. The third branch passage 1065 is equipped with a third valve 1066. The third branch passage 1065 and the second air passage 103 can be selectively connected through the third valve 1066.

[0037] Specifically, if surge occurs during the first compression stage of the centrifugal compressor 101, the first valve 1062 is opened to allow gas in the compression chamber of the centrifugal compressor 101 to flow back to the first gas path 102 via the first branch 1061, thereby reducing the gas pressure in the compression chamber and increasing the gas flow rate in the first gas path 102. Similarly, if surge occurs during the second compression stage of the centrifugal compressor 101, the second valve 1064 is opened to allow gas in the compression chamber of the centrifugal compressor 101 to flow back to the second gas path 103 via the second branch 1063, thereby reducing the gas pressure in the compression chamber and increasing the gas flow rate in the second gas path 103. If surge occurs during the third compression stage of the centrifugal compressor 101, the third valve 1066 is opened to allow gas in the compression chamber of the centrifugal compressor 101 to flow back to the third gas path 104 via the third branch 1065, thereby reducing the gas pressure in the compression chamber and increasing the gas flow rate in the third gas path 104.

[0038] The above embodiment, by setting up an anti-surge branch with an independent valve for each compression stage, enables independent and precise control of surge occurring during each compression stage. When surge occurs in a certain compression stage, simply opening the valve of the corresponding branch allows high-pressure gas to flow directionally back from the exhaust port of the centrifugal compressor 101 to the intake air path corresponding to the compression stage, thereby quickly reducing the pressure in the compression chamber and increasing the intake flow rate. This independently controlled anti-surge design improves the targetedness and immediacy of solving surge problems in the centrifugal compressor 101, ultimately achieving the goal of alleviating or eliminating surge in the centrifugal compressor 101. It also improves the operational stability, control accuracy, and reliability of the anti-surge system 10 under complex operating conditions.

[0039] In some embodiments, the first air passage 102 includes a first pipe 1022. The first pipe 1022 is connected to a first air inlet 1021 and is connected to a centrifugal compressor 101.

[0040] The first gas passage 102 includes a first intake valve 1023. The first intake valve 1023 is located in the first pipeline 1022, and by opening the first intake valve 1023, a section of gas is controlled to enter the centrifugal compressor 101.

[0041] The first gas path 102 includes a first sensing element group 1024. The first sensing element group 1024 is disposed in the first pipeline 1022 and is capable of acquiring first gas data about a gas segment, wherein the first gas data includes: first temperature data, first pressure data and first flow rate data.

[0042] Please refer to Figure 2A first intake valve 1023 is provided at one end of the first pipeline 1022 near the first intake port 1021, and a first sensing element group 1024 is provided at the other end of the first pipeline 1022 near the centrifugal compressor 101. The first intake valve 1023 can control whether a segment of gas enters the centrifugal compressor 101. The first sensing element group 1024 includes a first pressure sensor, a first temperature sensor, and a first flow sensor, wherein a Venturi sensor can be selected as the first flow sensor. The first flow sensor is located at the end of the first pipeline 1022 near the centrifugal compressor 101 to obtain the first flow rate data of a segment of gas entering the centrifugal compressor 101 through the first pipeline 1022; the first temperature sensor can be located on the side opposite to the centrifugal compressor 101 relative to the first flow sensor to obtain the first temperature data of a segment of gas; the first pressure sensor can be located between the first flow sensor and the first temperature sensor to obtain the first pressure data.

[0043] In the above embodiment, by integrating a first intake valve 1023 and a first sensing element group 1024 into the first gas path 102, effective control and real-time monitoring of the gas entering the centrifugal compressor 101 are achieved. The opening and closing of the first intake valve 1023 reliably controls the flow of the gas path; while in the first sensing element group 1024, the first flow sensor can measure the intake flow rate instantly and accurately, and the first temperature sensor and first pressure sensor can monitor the temperature and pressure of the gas in real time, respectively. This enables the anti-surge system 10 to acquire relevant information about the gas in real time, providing basic parameters for the operation monitoring of the centrifugal compressor 101, and laying the foundation for subsequent surge prediction, performance optimization, and automated control. This improves the intelligence level and response accuracy of the anti-surge system 10, thereby better ensuring the safe and stable operation of the centrifugal compressor 101.

[0044] In some embodiments, the second air passage 103 includes a second pipe 1032. The second pipe 1032 is connected to the second air inlet 1031 and is connected to the centrifugal compressor 101.

[0045] The second gas passage 103 includes a second intake valve 1033. The second intake valve 1033 is located in the second pipeline 1032, and the first supplementary gas is controlled to enter the centrifugal compressor 101 by opening the second intake valve 1033.

[0046] The second gas path 103 includes a second sensing element group 1034. The second sensing element group 1034 is disposed in the second pipeline 1032 and is capable of acquiring second gas data about the first supplementary gas, wherein the second gas data includes: second temperature data, second pressure data and second flow rate data.

[0047] The second gas passage 103 has the same structure as the first gas passage 102. A second intake valve 1033 is located at one end of the second pipe 1032 near the second intake port 1031. A second sensing element group 1034 is located at one end of the second pipe 1032 near the centrifugal compressor 101. The second intake valve 1033 controls whether the first supplementary gas enters the centrifugal compressor 101. The second sensing element group 1034 includes a second pressure sensor, a second temperature sensor, and a second flow sensor. A Venturi sensor can be used as the second flow sensor. The second flow sensor is located at one end of the second pipe 1032 near the centrifugal compressor 101 to obtain second flow data of the first supplementary gas entering the centrifugal compressor 101 via the second pipe 1032. The second temperature sensor can be located on the side opposite to the centrifugal compressor 101 relative to the second flow sensor to obtain second temperature data of the first supplementary gas. The second pressure sensor can be located between the second flow sensor and the second temperature sensor to obtain second pressure data.

[0048] In the above embodiment, the second intake valve 1033 in the second gas path 103 can control the first supplementary gas to enter the centrifugal compressor 101, and the second sensing element group 1034 can monitor the relevant data of the first supplementary gas entering the centrifugal compressor 101 in real time. When the centrifugal compressor 101 compresses the first mixed gas and surges, the acquired relevant data can be used to resolve the surge situation of the centrifugal compressor 101, so as to ensure the long-term stable operation of the centrifugal compressor 101.

[0049] In some embodiments, please refer to Figure 3 The third air passage 104 includes a third pipe 1042. The third pipe 1042 is connected to the third air inlet 1041 and is connected to the centrifugal compressor 101.

[0050] The third gas passage 104 includes a third intake valve 1043. The third intake valve 1043 is located in the third pipeline 1042, and the second supplementary gas is controlled to enter the centrifugal compressor 101 by opening the third intake valve 1043.

[0051] The third gas path 104 includes a third sensing element group 1044. The third sensing element group 1044 is disposed in the third pipeline 1042 and is capable of acquiring third gas data about the second supplementary gas, wherein the third gas data includes: third temperature data and third pressure data.

[0052] The third gas path 104 is identical in structure to the first gas path 102 and the second gas path 103, except that the third sensing element group 1044 no longer contains a flow sensor. Specifically, the structure is as follows: a third intake valve 1043 is installed at the end of the third pipeline 1042 near the third intake port 1041, and the third sensing element group 1044 is installed at the end of the third pipeline 1042 near the centrifugal compressor 101. The third intake valve 1043 controls whether the second supplementary gas enters the centrifugal compressor 101. The third sensing element group 1044 includes a third pressure sensor and a third temperature sensor. The third pressure sensor is located at the end of the third pipeline 1042 near the centrifugal compressor 101 to obtain third pressure data of the second supplementary gas entering the centrifugal compressor 101 via the third pipeline 1042; the third temperature sensor can be located on the side opposite to the centrifugal compressor 101 relative to the third pressure sensor to obtain second temperature data of the second supplementary gas.

[0053] In the above embodiment, since the third gas path 104 mainly introduces the second supplementary gas, the required flow rate data can be directly measured at the outlet 1011 of the centrifugal compressor 101. Therefore, the flow sensor in the third sensing element group is eliminated, thereby simplifying the structure of the anti-surge system 10 and reducing manufacturing costs and maintenance complexity. At the same time, the setting of the third intake valve 1043 still ensures the controllability of the gas path opening and closing, making the entire anti-surge system 10 more economical and adaptable while ensuring monitoring and control capabilities.

[0054] In some embodiments, the exhaust air passage 105 includes a distribution air passage 1051. The distribution air passage 1051 is disposed between the air outlet 1011 and the anti-surge air passage 106.

[0055] The exhaust gas path 105 includes an exhaust pipe 1053. The exhaust pipe 1053 is connected to the distribution pipe 1051 and is arranged in parallel with the anti-surge gas path 106. The third compressed gas can be discharged from the anti-surge system 10 through the exhaust pipe 1053.

[0056] The exhaust gas path 105 includes a fourth sensing element group 1054. The fourth sensing element group 1054 is disposed in the gas distribution line 1051, and the fourth sensing element group 1054 is capable of acquiring fourth gas data about the third compressed gas, wherein the fourth gas data includes: fourth temperature data, fourth pressure data, and fourth flow rate data.

[0057] Specifically, one end of the gas distribution pipeline 1051 is connected to the outlet 1011 of the centrifugal compressor 101. The gas discharged from the outlet 1011 of the centrifugal compressor 101 can flow to the anti-surge circuit or the exhaust pipeline 1053 only after passing through the gas distribution pipeline 1051. When the centrifugal compressor 101 does not experience surge during the third compression stage, the obtained third compressed gas can flow to the exhaust pipeline 1053 through the gas distribution pipeline 1051, and then flow out of the anti-surge system 10 and into the subsequent equipment. Therefore, a fourth sensing element group 1054 is installed on the gas distribution pipeline 1051 to monitor the fourth pressure data, fourth temperature data, and fourth flow rate data of the third compressed gas flowing out of the centrifugal compressor 101 in real time.

[0058] In the above embodiment, by setting the gas distribution pipeline 1051 as a common link connecting the outlet 1011 with the anti-surge gas path 106 and the exhaust pipeline 1053, it is ensured that the third compressed gas can flow smoothly to the downstream equipment through the exhaust pipeline 1053 under normal operating conditions, and a channel is provided for the gas that needs to flow back when the centrifugal compressor 101 experiences surge. The fourth sensing element group 1054 can acquire the temperature, pressure and flow data of the third compressed gas in real time, providing the anti-surge system 10 with complete status information of the centrifugal compressor 101 at the end of operation, enhancing the monitoring capability of the centrifugal compressor 101's operating conditions, and providing reliable data for predicting surge in the centrifugal compressor 101, evaluating the performance of the centrifugal compressor 101, and optimizing the anti-surge system 10, thereby improving the operational safety and reliability of the anti-surge system 10 under complex operating conditions.

[0059] In some embodiments, the gas distribution line 1051 includes a cooler 1052. The cooler 1052 is disposed in the gas distribution line 1051 and is disposed away from the centrifugal compressor 101 relative to the fourth sensing element group 1054.

[0060] After compression, the gas temperature rises. To lower the gas temperature, a cooler 1052 can be installed at the end of the gas distribution line 1051 near the exhaust line 1053 to reduce the temperature of the gas entering the anti-surge gas path 106 or the exhaust line 1053 from the gas distribution line 1051. Since the fourth sensing element group 1054 needs to collect the temperature of the third compressed gas formed by the centrifugal compressor 101, and the temperature of the third compressed gas will drop after entering the cooler 1052, the data needs to be collected before the third compressed gas enters the cooler 1052. Therefore, the fourth sensing element group 1054 is placed closer to the centrifugal compressor 101 than the cooler 1052, so that the fourth temperature data can be measured before the third compressed gas is cooled, improving the effectiveness of the acquired fourth temperature data.

[0061] In the above embodiment, by setting a cooler 1052 in the gas distribution pipeline 1051 and determining the positional relationship between the cooler 1052 and the fourth sensing element group 1054 on the gas distribution pipeline 1051, the embodiment achieves the goal of cooling the gas whose temperature rises after compression while ensuring the accuracy of the fourth temperature data of the third compressed gas. The cooler 1052 can cool the gas discharged from the centrifugal compressor 101 that is about to enter the anti-surge gas path 106 or the exhaust pipeline 1053 in a timely manner, thereby improving the safety and stability of the anti-surge system 10. By setting the fourth sensing element group 1054 before the cooler 1052 and closer to the centrifugal compressor 101, it is ensured that the temperature of the third compressed gas is accurately collected before it is cooled, avoiding temperature data distortion caused by cooling processing.

[0062] In some embodiments, the anti-surge system 10 further includes a controller. The controller is communicatively connected to the centrifugal compressor 101, the first intake valve 1023, the second intake valve 1033, and the third intake valve 1043. The controller can control the opening of the first intake valve 1023, the second intake valve 1033, or the third intake valve 1043 based on the operating state of the centrifugal compressor 101.

[0063] In actual operation, the first intake valve 1023, the second intake valve 1033, and the third intake valve 1043 are all controlled by the controller to open or close. The controller is connected to the centrifugal compressor 101 to obtain the working status of the centrifugal compressor 101. The controller determines that the centrifugal compressor 101 is in the first compression stage and controls the first intake valve 1023 to open, or determines that the centrifugal compressor 101 is in the second compression stage and controls the second intake valve 1033 to open, or determines that the centrifugal compressor 101 is in the third compression stage and controls the third intake valve 1043 to open, and automatically performs subsequent work.

[0064] In the above embodiments, the controller acquires the compressor's operating status in real time and accurately determines the current compression stage, thereby automatically controlling the opening of the corresponding intake valve to ensure that gas from each stage enters the centrifugal compressor 101 at the correct time. By automatically controlling the intake valve, control errors caused by human misjudgment or delay are avoided. Furthermore, the controller can respond quickly and accurately to the real-time operating conditions of the centrifugal compressor 101, ensuring the stable and efficient operation of the entire anti-surge system 10.

[0065] In some embodiments, the controller is also communicatively connected to the first sensing element group 1024, the second sensing element group 1034, the third sensing element group 1044, the fourth sensing element group 1054, the first valve 1062, the second valve 1064, and the third valve 1066, and the controller is also capable of performing steps 101 to 102: Step 101: The controller acquires the first gas data, the second gas data, the third gas data, and the fourth gas data.

[0066] Step 102: The controller controls the opening of the first valve 1062 to connect the first branch 1061 with the first gas path 102 based on the surge that occurs in the centrifugal compressor 101 during the first compression stage, and controls the opening degree of the first valve 1062 based on the first gas data and the second gas data.

[0067] The controller controls the opening of the second valve 1064 to connect the second branch 1063 with the second gas path 103 based on the surge that occurs in the centrifugal compressor 101 during the second compression stage, and controls the opening degree of the second valve 1064 based on the first gas data, the second gas data and the third gas data. The controller controls the opening of the third valve 1066 based on the surge that occurs in the centrifugal compressor 101 during the third compression stage, so that the third branch 1065 is connected to the third gas line 104, and controls the opening degree of the third valve 1066 based on the first gas data, the second gas data, the third gas data and the fourth gas data.

[0068] When the centrifugal compressor 101 in the refrigeration station is working, since the three stages of gas compression all occur in the same centrifugal compressor 101, it is impossible to obtain relevant data on the first compressed gas, the first mixed gas, the second compressed gas, and the second mixed gas. However, relevant data may be needed to control the first valve 1062, the second valve 1064, or the third valve 1066. Therefore, in this embodiment, the second pressure data is used to replace the pressure of the first compressed gas and the first mixed gas, the first flow data and the second flow data are superimposed to obtain the flow data of the second compressed gas, and the third pressure data is used to replace the pressure data of the second mixed gas, so that the controller can complete the relevant calculations.

[0069] After the controller determines that surge has occurred in the first compression stage, it then determines that the first valve 1062 needs to be opened. Subsequently, based on the first pressure data, the first flow data, and the second pressure data, it determines the first target pressure data and / or the first target flow data that the centrifugal compressor 101 needs to be adjusted, and determines the opening degree of the first valve 1062 based on the first target pressure data and / or the first target flow data. Similarly, after the controller determines that surge has occurred in the second compression stage, it then determines that the second valve 1064 needs to be opened. Based on the first temperature data, first flow data, second pressure data, second temperature data, second flow data, and third pressure data, it determines the second target pressure data and / or second target flow data that the centrifugal compressor 101 currently needs to adjust, and determines the opening degree of the second valve 1064 based on the second target pressure data and / or second target flow data. After the controller determines that surge has occurred in the third compression stage, it then determines that the third valve 1066 needs to be opened. Subsequently, based on the first temperature data, second temperature data, third pressure data, fourth pressure data, and fourth flow data, it determines the third target pressure data and / or third target flow data that the centrifugal compressor 101 currently needs to adjust, and determines the opening degree of the third valve 1066 based on the third target pressure data and / or third target flow data.

[0070] The above embodiments establish communication connections between the controller and each sensing element group and the anti-surge valve, enabling the controller to integrate acquired gas data in real time. When surge is detected at a certain compression stage, the controller automatically opens the corresponding branch's anti-surge valve and precisely adjusts the valve opening based on relevant gas data to determine the flow rate of the return gas and / or the released pressure, thereby quickly and effectively suppressing surge. For intermediate compression stage data that cannot be directly obtained, the controller performs relevant calculations using pre-configured alternative data, indirectly deriving relevant pressure and flow data. The control method provided by the above embodiments makes control decisions more scientific and accurate, improves the response speed and control precision of the anti-surge system 10, effectively reduces the burden of manual operation, and provides strong technical support for the safe, stable, and efficient operation of the centrifugal compressor 101 under complex multi-stage operating conditions.

[0071] This application also provides a compressor unit for a refrigeration plant, which includes the anti-surge system 10 for a refrigeration plant provided in any of the above embodiments. The compressor unit provided in this application has the anti-surge system 10 for a refrigeration plant as described in any of the above embodiments, and therefore has the beneficial effects of any of the above embodiments of the anti-surge system 10 for a refrigeration plant, which will not be elaborated here.

[0072] 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. An anti-surge system for a refrigeration station, characterized in that, include: Centrifugal compressor, including the air outlet; The first gas path includes a first inlet for receiving a section of gas. The first gas path is connected to the centrifugal compressor. The section of gas enters the centrifugal compressor through the first gas path to form a first compressed gas. The second gas path is connected to the centrifugal compressor. The second gas path includes a second inlet for receiving the first supplementary gas. After the first supplementary gas enters the centrifugal compressor through the second gas path, it mixes with the first compressed gas and is compressed by the centrifugal compressor to form the second compressed gas. The third gas path is connected to the centrifugal compressor. The third gas path includes a third inlet for receiving the second supplementary gas. After the second supplementary gas enters the centrifugal compressor through the third gas path, it mixes with the second compressed gas and is compressed by the centrifugal compressor to form the third compressed gas. An exhaust gas path is connected to the air outlet, and the exhaust gas path is used to discharge the third compressed gas from the anti-surge system; An anti-surge air passage is connected to the exhaust air passage. The anti-surge air passage can be selectively connected to the first air passage, the second air passage, and the third air passage. The anti-surge air passage is used to send the first compressed gas into the first air passage, or the second compressed gas into the second air passage, or the third compressed gas into the third air passage.

2. The anti-surge system for a refrigeration plant according to claim 1, characterized in that, The anti-surge airflow path includes: The first branch is connected to the exhaust gas path, and the first branch is equipped with a first valve. The first branch and the first gas path are selectively connected through the first valve. The second branch is connected to the exhaust gas path. The second branch is equipped with a second valve, and the second branch and the second gas path can be selectively connected through the second valve. The third branch is connected to the exhaust gas path, and the third branch is equipped with a third valve. The third branch is selectively connected to the second gas path through the third valve.

3. The anti-surge system for a refrigeration plant according to claim 2, characterized in that, The first air path includes: The first pipeline is connected to the first air inlet and is connected to the centrifugal compressor. A first intake valve is installed in the first pipeline, and the gas in a certain section is controlled to enter the centrifugal compressor by opening the first intake valve. A first sensing element group is disposed in the first pipeline. The first sensing element group is capable of acquiring first gas data about the gas segment, wherein the first gas data includes: first temperature data, first pressure data, and first flow rate data.

4. The anti-surge system for a refrigeration plant according to claim 3, characterized in that, The second air passage includes: The second pipeline is connected to the second air inlet and is connected to the centrifugal compressor. The second intake valve is located in the second pipeline. By opening the second intake valve, the first supplementary gas is controlled to enter the centrifugal compressor. The second sensing element group is disposed in the second pipeline. The second sensing element group is capable of acquiring second gas data about the first supplementary gas, wherein the second gas data includes: second temperature data, second pressure data, and second flow rate data.

5. The anti-surge system for a refrigeration plant according to claim 4, characterized in that, The third air passage includes: The third pipeline is connected to the third air inlet and is connected to the centrifugal compressor; The third intake valve is located in the third pipeline. By opening the third intake valve, the second supplementary gas is controlled to enter the centrifugal compressor. A third sensing element group is disposed in the third pipeline. The third sensing element group is capable of acquiring third gas data regarding the second supplementary gas, wherein the third gas data includes third temperature data and third pressure data.

6. The anti-surge system for a refrigeration plant according to claim 5, characterized in that, The exhaust gas path includes: The air distribution pipeline is located between the air outlet and the anti-surge air path; An exhaust pipe is connected to the gas distribution pipe and is arranged in parallel with the anti-surge gas path, and the third compressed gas can be discharged from the anti-surge system through the exhaust pipe; A fourth sensing element group is disposed in the gas distribution pipeline. The fourth sensing element group is capable of acquiring fourth gas data about the third compressed gas, wherein the fourth gas data includes: fourth temperature data, fourth pressure data, and fourth flow rate data.

7. The anti-surge system for a refrigeration plant according to claim 6, characterized in that, The gas distribution pipeline includes: A cooler is disposed in the gas distribution line, and the cooler is disposed away from the centrifugal compressor compared to the fourth sensing element group.

8. The anti-surge system for a refrigeration plant according to any one of claims 6 or 7, wherein the anti-surge system further comprises: The controller is communicatively connected to the centrifugal compressor, the first intake valve, the second intake valve, and the third intake valve. The controller can control the opening of the first intake valve, the second intake valve, or the third intake valve based on the operating state of the centrifugal compressor.

9. The anti-surge system for a refrigeration plant according to claim 8, wherein the controller is further communicatively connected to the first sensing element group, the second sensing element group, the third sensing element group, the fourth sensing element group, the first valve, the second valve, and the third valve, and the controller is further capable of: Acquire the first gas data, the second gas data, the third gas data, and the fourth gas data; When the centrifugal compressor generates the first compressed gas, a surge occurs. The first valve is controlled to open so that the first branch is connected to the first gas path. The opening and closing degree of the first valve is controlled based on the first gas data and the second gas data. When the centrifugal compressor generates the second compressed gas, a surge occurs, and the second valve is controlled to open so that the second branch is connected to the second gas path. The opening and closing degree of the second valve is controlled based on the first gas data, the second gas data, and the third gas data. When the centrifugal compressor generates the third compressed gas, a surge occurs, and the third valve is controlled to open so that the third branch is connected to the third gas path. The opening and closing degree of the third valve is controlled based on the first gas data, the second gas data, the third gas data, and the fourth gas data.

10. A compressor unit for a refrigeration plant, characterized in that, include: Anti-surge system for refrigeration plants as described in any one of claims 1 to 9 above.

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