Stepless control system device and method of multistage compressor, equipment and medium

Abstract

The invention relates to a stepless control system device and method of a multistage compressor, equipment and a medium, in particular to the field of ultrahigh pressure copolymer production. The compression unit comprises a first-stage compressor, a second-stage compressor, a third-stage compressor, a fourth-stage compressor, a fifth-stage compressor and a sixth-stage compressor which are connected in sequence; the first-stage compressor is provided with a first return valve; a second reflux valve is arranged between an exhaust port of the third-stage compressor and an air inlet of the first-stage compressor; the fourth-stage compressor is provided with a third reflux valve; a fourth reflux valve is arranged between an exhaust port of the sixth-stage compressor and an air inlet of the fifth-stage compressor; and both the first return valve and the third return valve are provided with stepless adjusting equipment. According to the device provided by the invention, the return valve is arranged at the specific position of the compressor unit, and the specific return valve is provided with the stepless adjusting equipment, so that the gas displacement and the shaft power of the compressor in the compression unit within the adjusting range are in a linear relation, and the shaft power of the compressor is reduced on year-on-year basis.

Description

Technical Field

[0001] The present invention relates to the field of ultra-high pressure copolymer production, and specifically to a stepless control system device and method, equipment, and medium for a multi-stage compressor, and more particularly to a stepless control system device and method, equipment, and medium for a multi-stage compressor used in ultra-high pressure copolymer production, and more particularly to a stepless control system device and method, equipment, and medium for a multi-stage compressor used in ethylene-vinyl acetate copolymer production. Background Art

[0002] At present, the load regulation of the compressor used in the ultra-high pressure copolymer production device, such as the ethylene-vinyl acetate copolymer production, is regulated by a reflux valve on the compressor gas pipeline, although 0-100% load control of the compressor can be achieved.

[0003] However, the actual work done by the compressor has not changed. During normal production of the compressor, the rated air volume is always greater than the actual required air volume, causing the opening of the reflux valve to be basically close to 30%-50%, resulting in the compressor doing useless work, seriously increasing the energy consumption of the compressor, and being unfavorable to the green and low-energy development of ethylene-vinyl acetate copolymer. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide a stepless control system device and method, equipment, and medium for a multi-stage compressor to solve the defects of the compressor unit in the current ultra-high pressure copolymer production device, such as the compressor doing useless work and high energy consumption.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a stepless control system device for a multi-stage compressor, the stepless control system device comprising:

[0007] at least one compression unit;

[0008] The compression unit comprises a primary compressor, a secondary compressor, a tertiary compressor, a quaternary compressor, a quintuple compressor and a sixth compressor connected in sequence;

[0009] The first stage compressor is provided with a first return valve via a first branch;

[0010] A second return valve is provided between the exhaust port of the three-stage compressor and the air inlet of the first-stage compressor;

[0011] The four-stage compressor is provided with a third return valve via a second branch;

[0012] A fourth return valve is provided between the exhaust port of the six-stage compressor and the air inlet of the five-stage compressor;

[0013] The first return valve and the third return valve are both equipped with stepless adjustment devices.

[0014] The stepless control system device provided by the present invention sets a return valve at a specific position of the compressor unit and configures a stepless adjustment device for the specific return valve, thereby achieving a linear relationship between the exhaust volume and the shaft power of the compressor in the compression unit within the adjustment range, reducing the compressor shaft power year-on-year, thereby effectively reducing the energy consumption of the compression unit.

[0015] As a preferred technical solution of the present invention, the first reflux valve, the second reflux valve, the third reflux valve, the fourth reflux valve and the stepless regulating device are all connected to the control unit.

[0016] In a second aspect, the present invention provides a stepless control system method for a multi-stage compressor, the stepless control system method comprising:

[0017] S1, start-up self-test, check whether the speed of the compression unit motor is the rated speed, if it is the rated speed, put the stepless adjustment device into use, otherwise confirm the motor;

[0018] S2, open the pressure relief valve and hydraulic oil input device of the stepless regulating device, and then control the OP value of the stepless regulating device to 100% load;

[0019] S3, adjust the opening of the pressure relief valve to control the outlet pressure of the hydraulic oil pump to the preset pressure value;

[0020] S4, lowering the OP value of the stepless regulating device corresponding to the first return valve until the valve positions of the first return valve and the second return valve are in a closed state, after which the stepless regulating device corresponding to the first return valve is automatically controlled to ensure that the first return valve and the second return valve are in a closed state;

[0021] S5. Reduce the OP value of the stepless regulating device corresponding to the third return valve until the controller output value of the stepless regulating device corresponding to the third return valve is ≥80%.

[0022] As a preferred technical solution of the present invention, the power-on self-test includes:

[0023] Check whether the compression unit motor speed is the rated speed. If it is the rated speed, use the stepless adjustment device. Otherwise, confirm the motor.

[0024] As a preferred technical solution of the present invention, when the hydraulic oil input device is turned on, the oil pressure is 0 bar. If the oil pressure is greater than 0 bar, the machine will shut down.

[0025] As a preferred technical solution of the present invention, the preset pressure value is 9-10MPa.

[0026] As a preferred technical solution of the present invention, the operating range of reducing the OP value of the stepless regulating device corresponding to the first reflux valve is ≤5%.

[0027] Preferably, the first return valve corresponding to the stepless regulating device is automatically controlled including: based on the set pressure value being 1.1-1.2 times the inlet pressure of the first-stage compressor, by controlling the OP value of the first return valve corresponding to the stepless regulating device so that the actual pressure value of the first return valve corresponding to the stepless regulating device is the same as the set pressure value.

[0028] As a preferred technical solution of the present invention, the operating range of reducing the OP value of the stepless regulating device corresponding to the third reflux valve is ≤1%.

[0029] Preferably, after the controller output value of the stepless regulating device corresponding to the third return valve is ≥80%, by adjusting the OP value of the stepless regulating device corresponding to the third return valve, the actual pressure value of the stepless regulating device corresponding to the third return valve is made the same as the set pressure value based on the set pressure value being 1.1-1.2 times the inlet pressure of the three-stage compressor.

[0030] In a third aspect, the present invention provides an electronic device, the electronic device comprising:

[0031] at least one processor; and a memory communicatively coupled to the at least one processor;

[0032] Wherein, the memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the stepless control system method described in the second aspect.

[0033] In a fourth aspect, the present invention provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the stepless control system method described in the first aspect is implemented.

[0034] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0035] (1) By applying the control method of the present invention, the unit can be slowly put into use after it is started and running stably, which can realize the load regulation of the compressor and also achieve the effect of reducing the useless work of the compressor, thus promoting energy saving and consumption reduction of the device.

[0036] (2) When the stepless regulating system corresponding to the compressor of the device provided by the present invention reports a fault, after a delay of 3-5 seconds, each return valve of the compressor automatically jumps to the valve position during normal production, which will not affect the outlet pressure of the compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic diagram of a stepless control system device for a multi-stage compressor provided by an embodiment of the present invention;

[0038] Figure 2 is a schematic diagram of an electronic device provided by an embodiment of the present invention;

[0039] Figure 3 This is a trend diagram of the compressor current after the stepless regulation control system in Example 1 of the present invention is put into use.

[0040] In the figure: 1-a first-stage compressor, 1.1-a first return valve, 2-a second-stage compressor, 3-a third-stage compressor, 3.1-a second return valve, 4-a fourth-stage compressor, 4.1-a third return valve, 5-a fifth-stage compressor, 6-a sixth-stage compressor, 6.1-a fourth return valve, 7-a stepless regulating device, 8-a control unit, 10-an electronic device, 11-a processor, 12-a ROM, 13-a RAM, 14-a bus, 15-an I / O interface, 16-an input unit, 17-an output unit, 18-a storage unit, 19-a communication unit;

[0041] The green line is the output value of the first return valve corresponding to the stepless adjustment device, the blue line is the output value of the third return valve corresponding to the stepless adjustment device, and the purple line is the total current of all compressors.

[0042] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0043] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0044] This embodiment provides a stepless control system device for a multi-stage compressor, such as Figure 1 As shown, the stepless control system device includes:

[0045] at least one compression unit;

[0046] The compression unit comprises a first-stage compressor 1, a second-stage compressor 2, a third-stage compressor 3, a fourth-stage compressor 4, a fifth-stage compressor 5 and a sixth-stage compressor 6 connected in sequence;

[0047] The first stage compressor 1 is provided with a first return valve 1.1 via a first branch;

[0048] A second return valve 3.1 is provided between the exhaust port of the third-stage compressor 3 and the air inlet of the first-stage compressor 1;

[0049] The four-stage compressor 4 is provided with a third return valve 4.1 via a second branch;

[0050] A fourth return valve 6.1 is provided between the exhaust port of the six-stage compressor 6 and the air inlet of the five-stage compressor 5;

[0051] The first return valve 1 . 1 and the third return valve 4 . 1 are both equipped with a stepless regulating device 7 .

[0052] The first return valve 1 . 1 , the second return valve 3 . 1 , the third return valve 4 . 1 , the fourth return valve 6 . 1 and the stepless regulating device 7 are all connected to a control unit 8 .

[0053] Furthermore, the present invention provides a stepless control system method for a multi-stage compressor, the stepless control system method comprising:

[0054] S1. After the power-on self-test, the pressure relief valve and hydraulic oil input device of the stepless regulating device 7 are turned on, and then the OP value of the stepless regulating device 7 is controlled to be 100% load;

[0055] S2. Adjust the opening of the pressure relief valve to control the outlet pressure of the hydraulic oil pump to the preset pressure value;

[0056] S3, lowering the OP value of the stepless regulating device 7 corresponding to the first return valve 1.1 until the valve positions of the first return valve 1.1 and the second return valve 3.1 are in a closed state, after which the stepless regulating device 7 corresponding to the first return valve 1.1 is automatically controlled to ensure that the first return valve 1.1 and the second return valve 3.1 are in a closed state;

[0057] S4, reducing the OP value of the stepless regulating device 7 corresponding to the third return valve 4.1 until the controller output value of the stepless regulating device 7 corresponding to the third return valve 4.1 is ≥80%.

[0058] When the hydraulic oil input device is turned on, the oil pressure is 0 bar. If the oil pressure is greater than 0 bar, the machine will shut down.

[0059] Wherein, the preset pressure value is 9-10MPa.

[0060] The operating range of reducing the OP value of the first return valve 1.1 corresponding to the stepless regulating device 7 is ≤5%.

[0061] Among them, the first return valve corresponding to the stepless regulating device is automatically controlled including: according to the set pressure value being 1.1-1.2 times of the inlet pressure of the first-stage compressor 1, by controlling the OP value of the first return valve 1.1 corresponding to the stepless regulating device 7, the actual pressure value of the first return valve 1.1 corresponding to the stepless regulating device 7 is made the same as the set pressure value.

[0062] The operating range of reducing the OP value of the stepless regulating device 7 corresponding to the third return valve 4.1 is ≤1%.

[0063] Among them, after the controller output value of the stepless regulating device corresponding to the third return valve is ≥80%, the OP value of the stepless regulating device 7 corresponding to the third return valve 4.1 is manually adjusted, and the actual pressure value of the stepless regulating device 7 corresponding to the third return valve 4.1 is made the same as the set pressure value based on the set pressure value being 1.1-1.2 times the inlet pressure of the three-stage compressor 3.

[0064] In the present invention, when the stepless regulating device fails, the stepless regulating control valves corresponding to the first return valve 1.1 and the third return valve 4.1 will automatically return to the initial state 100%, and the first return valve 1.1, the second return valve 3.1, the third return valve 4.1 and the fourth return valve 6.1 of the original compressor will also return to the original valve position state during normal operation. At this time, the pressure of each level of the compressor will fluctuate slightly, and the operator is required to fine-tune the bypass valve in time according to the pressure of each level to ensure that the pressure of each level of the compressor is stable.

[0065] In the present invention, when the stepless adjustment system needs to be manually cut out during the operation of the device, the controllers of the stepless adjustment devices corresponding to the first return valve 1.1 and the third return valve 4.1 can be manually adjusted to manual control, and slowly retreated to 100%. At this time, the original four bypass valves of the compressor are all in the automatic control state, and the valve positions of the four valves will return to the valve positions required during the normal operation of the compressor when the stepless adjustment system is exited. At this time, the stepless adjustment system can be shut down, and the pressure of each level of the compressor will not fluctuate, so that the stepless adjustment system of the compressor can be cut out without disturbance.

[0066] Further, the present embodiment provides an electronic device, which is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0067] like Figure 2As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. The I / O interface 15 is also connected to the bus 14.

[0068] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0069] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a stepless control system method for a multi-stage compressor.

[0070] In some embodiments, the stepless control system method for a multi-stage compressor can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the stepless control system method for a multi-stage compressor described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the stepless control system method for a multi-stage compressor by any other appropriate means (for example, by means of firmware).

[0071] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0072] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0073] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0074] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0075] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0076] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0077] The server provided in this embodiment includes: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the stepless control system method of the multi-stage compressor is implemented.

[0078] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0079] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments of the present invention may all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. A skilled person may implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present invention.

[0080] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0081] For software implementation, the techniques described in the present invention can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in the present application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0082] Further, in order to illustrate the good control effect that can be achieved by the stepless control system device for a multi-stage compressor provided by the present invention, the following practical examples are used for illustration, as follows:

[0083] Example 1

[0084] This embodiment provides a stepless control process for a multi-stage compressor used in the production of ethylene-vinyl acetate copolymer:

[0085] (1) Start the main motor of the primary machine and keep it running after the reflux valves at each level are adjusted stably. Confirm that the speed collected by the stepless cabinet touch screen is the rated speed of the main motor of the primary machine. If the speed is not the rated speed of the main motor of the primary machine, do not use the stepless control. Otherwise, use the stepless control.

[0086] (2) If there is no alarm information and the rated speed of the main motor is displayed as normal, the stepless regulation system is put into use first, and the pressure relief valve of the stepless regulation device 7 is opened.

[0087] (3) Turn the oil pressure bypass button in the DCS stepless interlocking logic diagram to "bypass" to ensure that the oil pressure of the stepless regulation equipment is normal.

[0088] (4) Start the on-site stepless adjustment system hydraulic oil station. At this time, the oil pressure should show 0 bar (if the pressure gauge is found to be upward, stop the pump immediately).

[0089] (5) The OP value of the controller of the stepless regulating device 7 corresponding to the first return valve 1.1 and the third return valve 4.1 is adjusted to 100% load.

[0090] (6) Start to pressurize, and the hydraulic oil pump outlet pressure is maintained at 10MPa.

[0091] (7) The OP value of the controller of the stepless regulating device 7 corresponding to the first return valve 1.1 is gradually reduced, and each operation is 3%. At this time, the original first return valve 1.1 and the second return valve 3.1 still maintain the automatic control state, and the return valve opening will be gradually and automatically reduced with the OP value of the controller until the valve positions of the first return valve 1.1 and the second return valve 3.1 are all closed to 0%. At this time, the controller of the stepless regulating device 7 corresponding to the first return valve 1.1 can be set to automatic control. The automatic control is based on a set pressure value of 1.1 times the inlet pressure of the first-stage compressor 1. By controlling the OP value of the stepless regulating device 7 corresponding to the first return valve 1.1, the actual pressure value of the stepless regulating device 7 corresponding to the first return valve 1.1 is made the same as the set pressure value, and the commissioning of the stepless regulating device 7 corresponding to the first return valve 1.1 is completed. The process and equipment professionals can be arranged on site to check whether the compressor is running normally.

[0092] (8) Gradually reduce the OP value of the controller of the stepless regulating device corresponding to the third return valve 4.1, and each operation is 1%. Because the overall pressure is high, the output value of the controller of the stepless regulating device corresponding to the third return valve 4.1 is guaranteed to be above 80% to prevent the output value from being too large, which will cause certain fluctuations in the original compressor valve action and the compressor outlet pressure. At this time, the control of the stepless regulating device corresponding to the third return valve 4.1 can still be manually controlled. By manually adjusting the OP value of the stepless regulating device 7 corresponding to the third return valve 4.1, the actual pressure value of the stepless regulating device 7 corresponding to the third return valve 4.1 is made the same as the set pressure value. The set pressure value is 1.2 times the inlet pressure of the three-stage compressor 3. When the controller of the stepless regulating device corresponding to the third return valve 4.1 reaches 80%, the process and equipment professionals can be arranged to check whether the operation of the compressor is normal.

[0093] After the stepless regulation control system of this embodiment is put into use, the compressor current trend diagram is as follows: Figure 3 As shown in the figure, the compressor current trend is downward, which significantly reduces the power used by the compressor and improves the energy utilization rate of the system.

[0094] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0095] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0096] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A stepless control system device for a multi-stage compressor, characterized in that: The stepless control system device comprises: at least one compression unit; The compression unit comprises a primary compressor, a secondary compressor, a tertiary compressor, a quaternary compressor, a quintuple compressor and a sixth compressor connected in sequence; The first stage compressor is provided with a first return valve via a first branch; A second return valve is provided between the exhaust port of the three-stage compressor and the air inlet of the first-stage compressor; The four-stage compressor is provided with a third return valve via a second branch; A fourth return valve is provided between the exhaust port of the six-stage compressor and the air inlet of the five-stage compressor; The first return valve and the third return valve are both equipped with stepless adjustment devices.

2. The stepless control system device according to claim 1, characterized in that: The first return valve, the second return valve, the third return valve, the fourth return valve and the stepless regulating device are all connected to the control unit.

3. A stepless control system method for a multi-stage compressor, characterized in that: The stepless control system method comprises: S1, start-up self-test, check whether the speed of the compression unit motor is the rated speed, if it is the rated speed, put the stepless adjustment device into use, otherwise confirm the motor; S2, open the pressure relief valve and hydraulic oil input device of the stepless regulating device, and then control the OP value of the stepless regulating device to 100% load; S3, adjust the opening of the pressure relief valve to control the outlet pressure of the hydraulic oil pump to the preset pressure value; S4, lowering the OP value of the stepless regulating device corresponding to the first return valve until the valve positions of the first return valve and the second return valve are in a closed state, after which the stepless regulating device corresponding to the first return valve is automatically controlled to ensure that the first return valve and the second return valve are in a closed state; S5. Reduce the OP value of the stepless regulating device corresponding to the third return valve until the controller output value of the stepless regulating device corresponding to the third return valve is ≥80%.

4. The stepless control system method according to claim 3, characterized in that: The power-on self-test includes: Check whether the compression unit motor speed is the rated speed. If it is the rated speed, use the stepless adjustment device. Otherwise, confirm the motor.

5. The stepless control system method according to claim 3, characterized in that: When the hydraulic oil input device is turned on, the oil pressure is 0 bar. If the oil pressure is greater than 0 bar, the machine will shut down.

6. The stepless control system method according to claim 3, characterized in that: The preset pressure value is 9-10 MPa.

7. The stepless control system method according to claim 3, characterized in that: The operation range of reducing the OP value of the stepless regulating device corresponding to the first reflux valve is ≤5%; The first return valve corresponding to the stepless regulating device is automatically controlled including: according to the set pressure value being 1.1-1.2 times of the inlet pressure of the first-stage compressor, by controlling the OP value of the first return valve corresponding to the stepless regulating device so that the actual pressure value of the first return valve corresponding to the stepless regulating device is the same as the set pressure value.

8. The stepless control system method according to claim 3, characterized in that: The operation range of reducing the OP value of the stepless regulating device corresponding to the third return valve is ≤1%; After the controller output value of the stepless regulating device corresponding to the third return valve is ≥80%, by adjusting the OP value of the stepless regulating device corresponding to the third return valve, the actual pressure value of the stepless regulating device corresponding to the third return valve is made the same as the set pressure value based on the set pressure value being 1.1-1.2 times the inlet pressure of the three-stage compressor.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively coupled to the at least one processor; The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the stepless control system method described in any one of claims 3-8.

10. A computer storage medium, characterized in that: The computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the stepless control system method described in any one of claims 3 to 8 is implemented.

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