Control system and method for controlling compressor

Abstract

The invention relates to the technical field of compressors, and discloses a control system and a control method of a compressor. An air suction flow path of the control system is connected with the air suction end of a compressor, an exhaust flow path is connected with the exhaust end of the compressor, and the air suction flow path and the exhaust flow path are further connected through a return valve. The control system has a boost mode. And in the boosting mode, the compressor is controlled to work, and the opening degree of the return valve is reduced, so that the exhaust pressure value rises to the set exhaust pressure value. In other words, the compressor adopts an automatic boosting design, so that the stability of the compressor in the boosting process can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of compressors, and in particular to a control system and a control method for a compressor. Background Art

[0002] Screw compressor is a commonly used industrial compressor, which is widely used in air compression, refrigeration, air conditioning, chemical industry, petroleum, natural gas and other fields. The screw compressor consists of two intermeshing screws (main screw and slave screw), which suck gas or steam from the air inlet end and compress it to the air outlet end through their rotational motion. The working principle of the screw compressor is to suck gas or steam from the air inlet end into the screw groove of the screw through the rotational motion of the screw. As the screw rotates, the gas or steam is gradually compressed and discharged at the air outlet end of the screw. The meshing shape and rotational motion of the screw cause the gas or steam to gradually reduce its volume and increase its density and pressure during the compression process. However, the current screw compressor has poor stability during operation under variable working conditions (such as boosting conditions, etc.). Summary of the invention

[0003] The present application provides a control system and a control method for a compressor, which can improve the stability of the compressor during a pressure boosting process.

[0004] The present application provides a control system. The control system includes a compressor. The control system also includes an intake flow path, which is connected to the intake end of the compressor. The control system also includes an exhaust flow path, which is connected to the exhaust end of the compressor, and the exhaust flow path is provided with an exhaust pressure detection element, which is used to detect the exhaust pressure value. The control system also includes a return valve, which is respectively connected to the intake flow path and the exhaust flow path. Among them, the control system has a boost mode. In the boost mode, the compressor is controlled to work, and the opening of the return valve is reduced so that the exhaust pressure value rises to the set exhaust pressure value.

[0005] In one embodiment of the present application, the control system also includes: an exhaust shut-off valve, which is arranged in the exhaust flow path; wherein, in the boost mode, the compressor is controlled to work and the exhaust shut-off valve is controlled to block the exhaust flow path, and the opening of the return valve is gradually reduced, so that the exhaust pressure value gradually increases until the exhaust pressure value rises to the set exhaust pressure value.

[0006] In one embodiment of the present application, the control system also includes: an intake pressure detection element, which is arranged in the intake air flow path, and the intake pressure detection element is used to detect the intake pressure value; and an oil pressure balancing plate, which is connected to the compressor; wherein the difference between the exhaust pressure value and the intake pressure value is the target difference; after each reduction in the opening of the return valve, and when the target difference is greater than the set pressure difference, the oil pressure balancing plate is used to balance the axial force applied to the compressor by the pressure difference between the exhaust air flow path and the intake air flow path; the set pressure difference is the maximum value of the target difference that the compressor can withstand.

[0007] In one embodiment of the present application, the control system also includes: an oil pressure regulating valve, connected to the oil pressure balancing disk; and an oil pressure detection element, connected to the oil pressure balancing disk, the oil pressure detection element being used to detect the oil pressure of the oil pressure balancing disk; wherein, after each reduction in the opening of the return valve, and when the target difference is greater than the set pressure difference, the set value of the oil pressure detected by the oil pressure detection element is the difference between the target difference and the set pressure difference, and the oil pressure regulating valve automatically adjusts its opening according to the set value.

[0008] In one embodiment of the present application, the control system also has a preparation mode; wherein, in the preparation mode, the compressor is in a shutdown state, the exhaust flow path is in a blocked state, and the opening of the return valve in the preparation mode is greater than the opening of the return valve in the boost mode.

[0009] In one embodiment of the present application, the control system also includes: an oil pressure balancing plate connected to the compressor; an oil pressure regulating valve connected to the oil pressure balancing plate; and an oil pressure detection element connected to the oil pressure balancing plate, the oil pressure detection element being used to detect the oil pressure of the oil pressure balancing plate; wherein, in the preparation mode, the set value of the oil pressure detected by the oil pressure detection element is the target oil pressure, and the oil pressure regulating valve automatically adjusts its opening according to the target oil pressure.

[0010] In one embodiment of the present application, the control system further includes: an intake cut-off valve disposed in the intake air flow path, the intake cut-off valve being configured to control the intake air flow path to be open in the boost mode and the preparation mode.

[0011] In one embodiment of the present application, the control system also has a shutdown mode; wherein, in the shutdown mode, the compressor is in a shutdown state, the intake air flow path and the exhaust air flow path are in a blocked state, and the opening of the return valve in the shutdown mode is greater than the opening of the return valve in the boost mode.

[0012] In one embodiment of the present application, the control system also includes: an oil pressure balancing plate connected to the compressor; an oil pressure regulating valve connected to the oil pressure balancing plate; and an oil pressure detection element connected to the oil pressure balancing plate, the oil pressure detection element being used to detect the oil pressure of the oil pressure balancing plate; wherein, in the shutdown mode, the set value of the oil pressure detected by the oil pressure detection element is the target oil pressure, and the oil pressure regulating valve automatically adjusts its opening according to the target oil pressure.

[0013] Accordingly, the present application also provides a control method for a compressor, which is based on the control system described in the above embodiment, and the control method includes: in response to a boost mode instruction, controlling the control system to enter a boost mode; in the boost mode, controlling the compressor of the control system to work, and reducing the opening of the return valve of the control system, so that the exhaust pressure value of the exhaust flow path of the control system rises to the set exhaust pressure value.

[0014] In one embodiment of the present application, the boost mode further includes: gradually increasing the set value of the exhaust pressure value; after each increase in the set value of the exhaust pressure value, reducing the opening of the return valve according to the set value of the exhaust pressure value, so that the exhaust pressure value rises to the current set value and maintains it for a preset time; until the exhaust pressure value rises to the set exhaust pressure value.

[0015] In one embodiment of the present application, after the step of the exhaust pressure value rising to the current set value and maintaining it for a preset time period includes: determining whether the difference between the exhaust pressure value and the intake pressure value of the intake air flow path is greater than the set pressure difference; if so, setting the set value of the oil pressure detected by the oil pressure detection element to the difference between the target difference and the set pressure difference, and controlling the oil pressure regulating valve to automatically adjust its opening according to the set value, wherein the target difference is the difference between the exhaust pressure value and the intake pressure value.

[0016] In one embodiment of the present application, in the boost mode, the exhaust flow path is in a blocked state; after the exhaust pressure value of the exhaust flow path of the control system rises to the set exhaust pressure value, the step includes: controlling the exhaust flow path to be conductive to complete the control system grid connection.

[0017] In one embodiment of the present application, after the step of the exhaust pressure value of the exhaust flow path of the control system rising to the set exhaust pressure value includes: judging whether the intake pressure value of the intake flow path of the control system is less than the set intake pressure value; if so, increasing the opening of the return valve.

[0018] The beneficial effects of the present application are as follows: Different from the prior art, the present application provides a control system and a control method for a compressor. The air intake flow path of the control system is connected to the air intake end of the compressor, and the exhaust flow path is connected to the exhaust end of the compressor, and the air intake flow path and the exhaust flow path are also connected via a return valve. The control system has a boost mode. In the boost mode, the compressor is controlled to work, and the opening of the return valve is reduced so that the exhaust pressure value rises to the set exhaust pressure value. In other words, the compressor of the present application adopts an automated boost design, which can improve the stability of the compressor during the boost process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of an embodiment of a control system of the present application;

[0021] Figure 2 It is a flow chart of the first embodiment of the control method of the compressor of the present application;

[0022] Figure 3 It is a flow chart of the second embodiment of the compressor control method of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application and are not used to limit the present application. In the present application, unless otherwise stated, the directional words used, such as "up", "down", "left", and "right", generally refer to the up, down, left, and right of the device in actual use or working state, specifically the drawing direction in the accompanying drawings.

[0024] In this application, unless otherwise clearly specified and limited, the terms "connected", "connected", "stacked" and the like should be understood in a broad sense, for example, it can be fixedly connected, detachably connected, or integrated; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0025] The present application provides a control system and a control method for a compressor, which are described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of the present application. In the following embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0026] In order to solve the technical problem of poor stability of screw compressors in the prior art during variable operating conditions, an embodiment of the present application provides a control system. The control system includes a compressor. The control system also includes an intake air flow path, which is connected to the intake end of the compressor. The control system also includes an exhaust air flow path, which is connected to the exhaust end of the compressor, and the exhaust air flow path is provided with an exhaust pressure detection element, which is used to detect the exhaust pressure value. The control system also includes a return valve, which is respectively connected to the intake air flow path and the exhaust air flow path. Among them, the control system has a boost mode. In the boost mode, the compressor is controlled to work, and the opening of the return valve is reduced so that the exhaust pressure value rises to the set exhaust pressure value. It is elaborated in detail below.

[0027] See also Figure 1 , Figure 1 It is a schematic diagram of an embodiment of a control system of the present application.

[0028] In one embodiment, the control system includes a compressor 10, an intake air flow path 20, and an exhaust air flow path 30. The intake air flow path 20 is connected to the intake end of the compressor 10, and the exhaust air flow path 30 is connected to the exhaust end of the compressor 10. The compressor 10 in this embodiment may be a screw compressor, etc. When the compressor 10 is working, a gas phase working medium is sucked into the compressor 10 from the intake air flow path 20, and the compressor 10 compresses the sucked gas phase working medium and discharges it through the exhaust air flow path 30.

[0029] Furthermore, the control system further includes an electric motor 80 , which is connected to the compressor 10 , and is used to drive the compressor 10 to work.

[0030] In one embodiment, the control system further includes an oil pressure balancing plate 50, which is connected to the compressor 10. When the axial force on the screw rotor of the compressor 10 is large, the oil pressure balancing plate 50 uses lubricating oil as a medium to balance the pressure to both sides through oil holes or channels, thereby balancing the axial force directed from the exhaust end to the suction end. In the case where the oil pressure balancing plate 50 is controlled by a manual valve, when the compressor 10 is started and shut down, the adjustment ability, adaptability, and timeliness of the oil pressure balancing plate 50 are relatively poor, and manual operation is cumbersome, prone to misoperation and untimely response. In view of this, this embodiment automatically realizes the oil pressure adjustment of the oil pressure balancing plate 50 by setting a control system, which can efficiently, accurately, safely and labor-savingly solve the stability problem of the compressor 10 during variable operating conditions, that is, ensure the stability of the compressor 10 during variable operating conditions.

[0031] In one embodiment, the control system further includes an oil pressure regulating valve 60, which is connected to the oil pressure balancing disk 50. The oil inlet 51 is connected to the oil pressure balancing disk 50 through the oil pressure regulating valve 60, and the oil pressure of the oil pressure balancing disk 50 can be adjusted by adjusting the opening of the oil pressure regulating valve 60. The control system further includes an oil pressure detection element 70, which is connected to the oil pressure balancing disk 50, and the oil pressure detection element 70 is used to detect the oil pressure of the oil pressure balancing disk 50. Optionally, the oil pressure detection element 70 can be connected to the flow path between the oil pressure regulating valve 60 and the oil pressure balancing disk 50.

[0032] In one embodiment, the air intake port 23 is connected to the air intake end of the compressor 10 through the air intake flow path 20, and the external gas phase working medium enters the air intake flow path 20 from the air intake port 23 and is sucked into the compressor 10 through the air intake flow path 20. The control system further includes an air intake cut-off valve 22, which is disposed on the air intake flow path 20 and is configured to control whether the air intake flow path 20 is blocked or opened.

[0033] In one embodiment, the control system further includes an intake pressure detection element 21, which is disposed in the intake air flow path 20 and is used to detect an intake pressure value. Optionally, the intake pressure detection element 21 can be connected to the intake air flow path 20 between the intake shut-off valve 22 and the compressor 10.

[0034] In one embodiment, the control system also includes an exhaust shut-off valve 32, and the compressor 10 is connected to the exhaust port 33 through the exhaust shut-off valve 32. The gas phase working fluid compressed by the compressor 10 flows through the exhaust flow path 30 and is discharged from the exhaust port 33. The exhaust shut-off valve 32 is configured to control whether the exhaust flow path 30 is blocked or opened.

[0035] In one embodiment, the control system further includes an exhaust pressure detection element 31, which is disposed in the exhaust flow path 30 and is used to detect the exhaust pressure value. Optionally, the exhaust pressure detection element 31 can be connected to the exhaust flow path 30 between the compressor 10 and the exhaust shut-off valve 32.

[0036] In one embodiment, the control system further includes a return valve 40, which is respectively connected to the intake air path 20 and the exhaust air path 30. In other words, the intake air path 20 and the exhaust air path 30 are connected not only through the compressor 10, but also through the return valve 40. The return valve 40 is configured to adjust the pressure difference between the intake air path 20 and the exhaust air path 30. Specifically, by adjusting the opening of the return valve 40, the degree of conduction between the intake air path 20 and the exhaust air path 30 can be adjusted, thereby adjusting the pressure difference between the intake air path 20 and the exhaust air path 30.

[0037] The following is an explanation of the control method of the compressor according to the embodiment of the present application. It should be noted that the control method of the compressor according to the following is based on the control system explained in the above embodiment.

[0038] See also Figure 2 , Figure 2 It is a flow chart of the first embodiment of the compressor control method of the present application.

[0039] S101: In response to a boost mode instruction, controlling a control system to enter a boost mode.

[0040] In this embodiment, in response to the boost mode instruction, the control system is controlled to enter the boost mode. In the boost mode, the control system automatically controls the compressor 10 to work to compress the gas phase working medium, so that the pressure of the gas phase working medium compressed by the compressor 10 reaches a set value. This embodiment realizes the automatic boost design of the compressor 10 through the control system, which can improve the stability of the compressor 10 during the boost process.

[0041] S102: In the boost mode, the compressor of the control system is controlled to operate, and the opening of the return valve of the control system is reduced, so that the exhaust pressure value of the exhaust flow path of the control system increases to a set exhaust pressure value.

[0042] In this embodiment, after the control system enters the boost mode, in the boost mode, the compressor 10 is controlled to work and the opening of the return valve 40 is reduced, that is, the degree of conductivity between the intake flow path 20 and the exhaust flow path 30 is reduced, and the exhaust pressure value of the exhaust flow path 30 will gradually increase, and finally the exhaust pressure value of the exhaust flow path 30 will increase to the set exhaust pressure value, thereby completing the boost process.

[0043] See also Figure 3 , Figure 3 It is a flow chart of the second embodiment of the compressor control method of the present application.

[0044] S201: The control system enters a preparation mode.

[0045] In this embodiment, the control system enters the preparation mode. In the preparation mode, the exhaust flow path 30 is in a blocked state, specifically, the exhaust flow path 30 is blocked by the exhaust shut-off valve 32. The compressor 10 is in a shutdown state. The return valve 40 is in a fully open state, that is, the opening of the return valve 40 reaches the maximum, so that the suction pressure value of the suction flow path 20 and the exhaust pressure value of the exhaust flow path 30 are as consistent as possible.

[0046] When the compressor 10 is shut down, there is still an axial force inside the compressor 10 that needs to be balanced by the oil pressure balancing disk 50. The oil pressure regulating valve 60 switches to the automatic adjustment state. The set value of the oil pressure detected by the oil pressure detection element 70 is the target oil pressure, and the target oil pressure is defined as the oil pressure corresponding to the oil pressure balancing disk 50 balancing the internal axial force of the compressor 10 when the compressor 10 is shut down. The oil pressure regulating valve 60 automatically adjusts its opening according to the target oil pressure, so that the oil pressure detected by the oil pressure detection element 70 is maintained at the target oil pressure as much as possible. This embodiment automatically realizes the oil pressure regulation of the oil pressure balancing disk 50 through the control system, and avoids as much as possible the poor adjustment ability, adaptability and timeliness of the oil pressure balancing disk 50 when the manual valve control is adopted, the manual operation is cumbersome, and it is easy to have problems such as misoperation and untimely response. It can efficiently, accurately, safely and labor-savingly solve the stability problem of the compressor 10 in the process of variable working conditions, that is, to ensure the stability of the compressor 10 in the process of variable working conditions.

[0047] Furthermore, in the preparation mode, the intake cut-off valve 22 is configured to control the conduction of the intake air flow path 20, which can avoid the formation of negative pressure in the intake air flow path 20 as much as possible, which is conducive to ensuring compression matching.

[0048] S202: Control the compressor and the motor to start.

[0049] In this embodiment, the compressor 10 and the motor 80 are controlled to start, and the speed of the motor 80 reaches the rated speed and maintains stable operation.

[0050] S203: The control system enters a boost mode.

[0051] In this embodiment, the control system enters the boost mode. In the boost mode, the compressor 10 is controlled to work, and the opening of the return valve 40 is reduced so that the exhaust pressure value of the exhaust flow path 30 rises to the set exhaust pressure value. The opening of the return valve 40 in the preparation mode is greater than the opening of the return valve 40 in the boost mode. Specifically, in the boost mode, the compressor 10 is in a working state, and the exhaust shut-off valve 32 remains in a state of blocking the exhaust flow path 30; and, the opening of the return valve 40 is gradually reduced so that the exhaust pressure value gradually rises until the exhaust pressure value rises to the set exhaust pressure value. In the boost mode, the intake shut-off valve 22 is configured to control the conduction of the intake flow path 20, which can avoid the formation of negative pressure in the intake flow path 20 as much as possible, which is conducive to ensuring compression matching.

[0052] Furthermore, the boost mode of the control system specifically includes: gradually increasing the set value of the exhaust pressure value; after each increase in the set value of the exhaust pressure value, reducing the opening of the return valve 40 according to the current set value of the exhaust pressure value, so that the exhaust pressure value rises to the current set value and maintains it for a preset time; until the exhaust pressure value rises to the set exhaust pressure value.

[0053] Furthermore, the difference between the exhaust pressure value and the suction pressure value is the target difference. A set pressure difference is defined, and the set pressure difference is the maximum value of the target difference that the compressor 10 can withstand. After each increase in the set value of the exhaust pressure value, wait for the exhaust pressure value to rise to the current set value and maintain the preset time, and judge whether the difference between the exhaust pressure value and the suction pressure value is greater than the set pressure difference. If the difference between the exhaust pressure value and the suction pressure value is greater than the set pressure difference, the set value of the oil pressure detected by the oil pressure detection element 70 is set to the difference between the target difference and the set pressure difference, and control the oil pressure regulating valve 60 to automatically adjust its opening according to the set value, and automatically adjust the oil pressure of the oil pressure balancing plate 50, so as to balance the axial force applied to the compressor 10 by the pressure difference between the current exhaust flow path 30 and the suction flow path 20 through the oil pressure balancing plate 50.

[0054] Through the above-mentioned method, in this embodiment, when the target difference is greater than the set pressure difference, the oil pressure of the oil pressure balancing plate 50 is adjusted to balance the axial force applied to the compressor 10 by the pressure difference between the current exhaust flow path 30 and the intake flow path 20, which is beneficial to ensuring the stability of the compressor 10 and extending the service life of the compressor 10. In addition, this embodiment automatically realizes the oil pressure regulation of the oil pressure balancing plate 50 through the control system, and avoids as much as possible the problems of poor adjustment ability, adaptability and timeliness of the oil pressure balancing plate 50 when the manual valve control is adopted, cumbersome manual operation, and prone to misoperation and untimely response. The stability problem of the compressor 10 in the process of variable operating conditions can be solved efficiently, accurately, safely and labor-savingly, that is, the stability of the compressor 10 in the process of variable operating conditions can be ensured.

[0055] For example, the suction pressure value is defined as P1, the exhaust pressure value is defined as P2, and the set pressure difference value is M.

[0056] Adjust the exhaust pressure value P2 for the first time: set the current setting value of the exhaust pressure value P2 to n1, n1=P1+p (p can be 0.1MPa, etc.); close the opening of the return valve 40, and the exhaust pressure value P2 rises. Wait for the exhaust pressure value P2 to rise to the current setting value n1 and maintain it for a preset time.

[0057] Adjust the exhaust pressure value P2 for the second time: set the current setting value of the exhaust pressure value P2 to n2, n2 = n1 + p; the opening of the return valve 40 is closed, the exhaust pressure value P2 rises, and the exhaust pressure value P2 rises to the current setting value n2 and maintains the preset time. Determine whether the difference between the exhaust pressure value P2 and the suction pressure value P1 is greater than the set pressure difference M. If the difference between the exhaust pressure value P2 and the suction pressure value P1 is greater than the set pressure difference M, then set the setting value of the oil pressure detected by the oil pressure detection element 70 to the difference between the target difference and the set pressure difference, that is, the current setting value of the oil pressure detected by the oil pressure detection element 70 is P2-P1-M, and control the oil pressure regulating valve 60 to automatically adjust its opening according to the setting value, and automatically adjust the oil pressure of the oil pressure balancing plate 50, so as to balance the axial force applied to the compressor 10 by the pressure difference between the current exhaust flow path 30 and the suction flow path 20 through the oil pressure balancing plate 50. If the difference between the exhaust pressure value P2 and the intake pressure value P1 is less than or equal to the set pressure difference value M, the oil pressure regulating valve 60 does not operate.

[0058] Adjust the exhaust pressure value P2 for the third time: set the current setting value of the exhaust pressure value P2 to n3, n3 = n2 + p; the opening of the return valve 40 is closed, the exhaust pressure value P2 rises, and the exhaust pressure value P2 rises to the current setting value n3 and maintains the preset time. Determine whether the difference between the exhaust pressure value P2 and the suction pressure value P1 is greater than the set pressure difference M. If the difference between the exhaust pressure value P2 and the suction pressure value P1 is greater than the set pressure difference M, then set the setting value of the oil pressure detected by the oil pressure detection element 70 to the difference between the target difference and the set pressure difference, that is, the current setting value of the oil pressure detected by the oil pressure detection element 70 is P2-P1-M, and control the oil pressure regulating valve 60 to automatically adjust its opening according to the setting value, and automatically adjust the oil pressure of the oil pressure balancing plate 50, so as to balance the axial force applied to the compressor 10 by the pressure difference between the current exhaust flow path 30 and the suction flow path 20 through the oil pressure balancing plate 50. If the difference between the exhaust pressure value P2 and the intake pressure value P1 is less than or equal to the set pressure difference value M, the oil pressure regulating valve 60 does not operate.

[0059] And so on, until the exhaust pressure value P2 rises to the set exhaust pressure value, the pressure boosting process of the control system is completed.

[0060] S204: Control system connected to the grid.

[0061] In this embodiment, in the boost mode, the exhaust flow path 30 is in a blocked state. When the exhaust pressure value rises to the set exhaust pressure value, the exhaust flow path 30 is controlled to be connected to complete the control system grid connection. Specifically, when the exhaust pressure value rises to the set exhaust pressure value, the exhaust shut-off valve 32 can be controlled to connect the exhaust flow path 30, and the compressed gas phase working medium is output to the subsequent links through the exhaust flow path 30 to achieve the control system grid connection.

[0062] Furthermore, the suction pressure value of the suction flow path 20 can be adjusted by adjusting the opening of the return valve 40. After the exhaust pressure value of the exhaust flow path 30 of the above-mentioned control system rises to the set exhaust pressure value, it includes: judging whether the suction pressure value of the suction flow path 20 of the control system is less than the set suction pressure value; if so, increasing the opening of the return valve 40. Specifically, after the control system is connected to the grid, the exhaust pressure value of the exhaust flow path 30 is constant; if the suction pressure value is less than the set suction pressure value (which can be reasonably set according to actual needs), that is, the suction pressure value is too small, the opening of the return valve 40 can be increased, so that the gas phase working medium in the exhaust flow path 30 flows back to the suction flow path 20 through the return valve 40, thereby increasing the suction pressure value. If the suction pressure value is too large, the rotation speed of the compressor 10 can be increased, and the processing capacity of the compressor 10 can be increased, so that the suction pressure value decreases to a certain extent.

[0063] It should be noted that the control system also has a shutdown mode, and the control system enters the shutdown mode when a fault interlock shutdown or a normal shutdown occurs. In the shutdown mode, the compressor 10 is in a shutdown state, the intake air flow path 20 and the exhaust air flow path 30 are in a blocked state, and the opening of the return valve 40 in the shutdown mode is greater than the opening of the return valve 40 in the boost mode. Specifically, in the shutdown mode, the intake cut-off valve 22 is controlled to block the intake air flow path 20, and the exhaust cut-off valve 32 is controlled to block the exhaust air flow path 30; the return valve 40 is opened, and the pressure difference between the intake air flow path 20 and the exhaust cut-off valve 32 is balanced by the return valve 40 to avoid damage to the control system (especially the compressor 10); the set value of the oil pressure detected by the oil pressure detection element 70 is the target oil pressure, and the oil pressure regulating valve 60 automatically adjusts its opening according to the target oil pressure, so that the oil pressure detected by the oil pressure detection element 70 is kept at the target oil pressure as much as possible, so as to balance the axial force of the compressor 10 in the shutdown state through the oil pressure balancing disk 50. This embodiment automatically achieves a balanced pressure difference between the intake air flow path 20 and the exhaust shut-off valve 32, and avoids as much as possible the use of manual valve control, which has poor adjustment ability, adaptability, and timeliness, and cumbersome manual operation, and is prone to misoperation and untimely response. It can efficiently, accurately, safely and labor-savingly solve the stability problem of the compressor 10 during variable operating conditions, that is, ensure the stability of the compressor 10 during variable operating conditions.

[0064] The control system and the compressor control method provided by the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for general technicians in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A control system, characterized in that: include: compressor; An air intake path connected to the air intake end of the compressor; An exhaust flow path connected to the exhaust end of the compressor, wherein the exhaust flow path is provided with an exhaust pressure detection element, and the exhaust pressure detection element is used to detect the exhaust pressure value; as well as a reflux valve connected to the intake flow path and the exhaust flow path respectively; Wherein, the control system has a boost mode; in the boost mode, the compressor is controlled to work and the opening of the return valve is reduced so that the exhaust pressure value rises to a set exhaust pressure value.

2. The control system according to claim 1, characterized in that: The control system further comprises: an exhaust shut-off valve, disposed in the exhaust flow path; Among them, in the boost mode, the compressor is controlled to work and the exhaust shut-off valve is controlled to block the exhaust flow path, and the opening of the return valve is gradually reduced, so that the exhaust pressure value gradually increases until the exhaust pressure value increases to the set exhaust pressure value.

3. The control system according to claim 2, characterized in that: The control system further comprises: an inhalation pressure detection element, disposed in the inhalation flow path, the inhalation pressure detection element being used to detect an inhalation pressure value; and An oil pressure balancing plate connected to the compressor; Among them, the difference between the exhaust pressure value and the intake pressure value is a target difference; after each reduction in the opening of the return valve, and when the target difference is greater than a set pressure difference, the oil pressure balancing plate is used to balance the axial force applied to the compressor by the pressure difference between the exhaust flow path and the intake flow path; the set pressure difference is the maximum value of the target difference that the compressor can withstand.

4. The control system according to claim 3, characterized in that: The control system further comprises: an oil pressure regulating valve connected to the oil pressure balancing disk; and An oil pressure detection element connected to the oil pressure balancing plate, the oil pressure detection element is used to detect the oil pressure of the oil pressure balancing plate; Among them, after each reduction in the opening of the return valve, and when the target difference is greater than the set pressure difference, the set value of the oil pressure detected by the oil pressure detection element is the difference between the target difference and the set pressure difference, and the oil pressure regulating valve automatically adjusts its opening according to the set value.

5. The control system according to claim 1, characterized in that: The control system also has a preparation mode; Wherein, in the preparation mode, the compressor is in a stopped state, the exhaust flow path is in a blocked state, and the opening degree of the return valve in the preparation mode is greater than the opening degree of the return valve in the boost mode.

6. The control system according to claim 5, characterized in that: The control system further comprises: An oil pressure balancing plate connected to the compressor; an oil pressure regulating valve connected to the oil pressure balancing disk; and An oil pressure detection element connected to the oil pressure balancing plate, the oil pressure detection element is used to detect the oil pressure of the oil pressure balancing plate; Wherein, in the preparation mode, the set value of the oil pressure detected by the oil pressure detection element is the target oil pressure, and the oil pressure regulating valve automatically adjusts its opening according to the target oil pressure.

7. The control system according to claim 5 or 6, characterized in that: The control system further comprises: An air intake cutoff valve is provided in the air intake passage, and the air intake cutoff valve is configured to control the flow of the air intake passage in the pressure increase mode and the preparation mode.

8. The control system according to claim 1, characterized in that: The control system also has a shutdown mode; Wherein, in the shutdown mode, the compressor is in a shutdown state, the intake air path and the exhaust air path are in a blocked state, and the opening of the return valve in the shutdown mode is greater than the opening of the return valve in the boost mode.

9. The control system according to claim 8, characterized in that: The control system further comprises: An oil pressure balancing plate connected to the compressor; an oil pressure regulating valve connected to the oil pressure balancing disk; and An oil pressure detection element connected to the oil pressure balancing plate, the oil pressure detection element is used to detect the oil pressure of the oil pressure balancing plate; Wherein, in the shutdown mode, the set value of the oil pressure detected by the oil pressure detection element is the target oil pressure, and the oil pressure regulating valve automatically adjusts its opening according to the target oil pressure.

10. A method for controlling a compressor, characterized in that: The control method is based on the control system according to any one of claims 1 to 9, and the control method includes: In response to a boost mode instruction, controlling the control system to enter a boost mode; In the boost mode, the compressor of the control system is controlled to operate, and the opening of the return valve of the control system is reduced, so that the exhaust pressure value of the exhaust flow path of the control system increases to a set exhaust pressure value.

11. The control method according to claim 10, characterized in that: The boost mode further includes: gradually increasing the set value of the exhaust pressure value; After each increase in the set value of the exhaust pressure value, the opening of the return valve is reduced according to the set value of the exhaust pressure value, so that the exhaust pressure value rises to the current set value and is maintained for a preset time; Until the exhaust pressure value rises to the set exhaust pressure value.

12. The control method according to claim 11, characterized in that: The step of increasing the exhaust pressure value to the current set value and maintaining it for a preset time period includes: Determine whether the difference between the exhaust pressure value and the intake pressure value of the intake air flow path is greater than a set pressure difference; If so, the set value of the oil pressure detected by the oil pressure detection element is set as the difference between the target difference and the set pressure difference, and the oil pressure regulating valve is controlled to automatically adjust its opening according to the set value, wherein the target difference is the difference between the exhaust pressure value and the intake pressure value.

13. The control method according to claim 10, characterized in that: In the boost mode, the exhaust flow path is in a blocked state; After the exhaust pressure value of the exhaust flow path of the control system rises to the set exhaust pressure value, the step includes: The exhaust gas flow path is controlled to be open to complete the control system being connected to the grid.

14. The control method according to claim 10, characterized in that: After the exhaust pressure value of the exhaust flow path of the control system rises to the set exhaust pressure value, the step includes: Determining whether the inhalation pressure value of the inhalation flow path of the control system is less than a set inhalation pressure value; If so, the opening of the return valve is increased.

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