A multi-stage coordinated gas supply system and control method

Abstract

The application discloses a kind of multistage coordinated gas supply system and control method, belong to industrial gas supply technical field, system contains main gas supply module, at least one auxiliary gas supply module, gas storage module and electric control module, main gas supply module is by frequency conversion main air compressor sequentially connected check valve, pressure transmitter by pipeline, auxiliary gas supply module is by fixed-frequency auxiliary air compressor sequentially connected buffer tank, pressure transmitter, electric regulating valve and check valve, electromagnetic pressure relief valve and electric regulating valve are connected in parallel, two-way gas source is merged after access gas storage module, and electric control module is based on dynamic pressure sampling control main auxiliary module start-stop and valve opening degree.The scheme solves the problems of low energy efficiency, large pressure fluctuation, response lag and poor redundancy of traditional gas supply system, can effectively suppress pipe network pressure oscillation, reduce comprehensive energy consumption, improve gas supply stability and operation reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial gas supply, and specifically relates to a multi-stage cooperative gas supply system and control method. Background Art

[0002] A gas supply system mainly compresses and stores gas, then delivers the gas at a certain pressure to a pneumatic mechanism. Traditional compressed air systems mostly adopt a simple gas source matching main equipment, a single air compressor gas source, or a simple primary-standby mode, which has the following defects: low energy efficiency, a single variable-frequency air compressor or fixed-frequency air compressor needs to operate at high frequency when there is a high-pressure demand, leading to a sharp increase in energy consumption, and long-term high-frequency operation accelerates equipment loss, resulting in a shortened service life of the equipment; large pressure fluctuations, sudden gas demand easily causes pressure oscillation of the pipe network, affecting the operation of precision equipment; when multiple units are connected in parallel, the superposition of airflow pulsations easily causes pressure oscillation of the pipe network, and even leads to surge phenomenon; response lag, the fixed sampling period cannot adapt to the working condition of sudden pressure change, and control delay leads to overshoot or regulation failure; poor redundancy, the switching delay of the standby unit is long, and seamless connection cannot be realized; the intervention logic of auxiliary modules is single, and there is a lack of rapid pressure relief protection in case of pressure imbalance, which easily causes equipment failure.

[0003] The Chinese patent with the publication number CN218563852U discloses a parallel air supply system for air compressors, which includes three ten thousand air compressors, the bottom of the three ten thousand air compressors is provided with forty thousand air compressors, one side of the three ten thousand air compressors and the forty thousand air compressors is communicated with a first connecting pipe, one end of the first connecting pipe is communicated with a second connecting pipe, one side of the second connecting pipe is communicated with a third connecting pipe, the other end of the third connecting pipe is communicated with an air storage tank, one side of the air storage tank is communicated with a fourth connecting pipe, a pressure sensor is bolted inside the fourth connecting pipe, and the pressure sensor is connected with a DCS distributed control system; this parallel gas supply system adopts a centralized gas supply mode, two air compressors operate at the same time, the set operating pressure difference is controlled at 5-10kpa, and the three ten thousand air compressors are used to increase the air delivery volume to the forty thousand air compressors. However, this parallel gas supply system still has the problem that the superposition of airflow pulsations when multiple units are connected in parallel is not considered, which may cause pressure oscillation of the pipe network; relying only on a single pressure sensor inside the fourth connecting pipe, it is difficult to achieve fast response and precise regulation; the air compressors also adopt the power frequency mode, and the energy consumption of the system is relatively high. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-level coordinated gas supply system and control method, comprising a variable frequency main gas supply module, a fixed frequency auxiliary gas supply module, a gas storage module, and an electronic control module. The main and auxiliary gas sources merge and are connected to the gas storage tank output. The auxiliary branch is equipped with a buffer tank and parallel electric regulating valves and electromagnetic pressure relief valves. The electronic control module dynamically adjusts the sampling period based on the pressure change rate and achieves smooth switching between the main and auxiliary gas supply modes through graded threshold logic. The auxiliary gas source adopts a progressive grid-connected control at a fractional rate. This scheme can effectively reduce the overall energy consumption of the gas supply system, reduce equipment losses under high load operation, significantly smooth pipeline pressure fluctuations, eliminate surge phenomena in multi-machine parallel operation, and improve the response speed under sudden pressure changes. Simultaneously, it constructs a gas source redundancy and multi-level protection mechanism, balancing gas supply stability, energy efficiency, and operational reliability, thus solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A multi-stage coordinated gas supply system includes a main gas supply module, at least one auxiliary gas supply module, a gas storage module, and an electrical control module;

[0007] The main air supply module includes a main air compressor, a first pressure pipeline, a first check valve, and a first pressure transmitter. The exhaust end of the main air compressor is connected to the beginning end of the first pressure pipeline. The first check valve and the first pressure transmitter are installed sequentially on the first pressure pipeline along the airflow direction.

[0008] The auxiliary air supply module includes an auxiliary air compressor, a second pressure pipeline, a buffer tank, a second pressure transmitter, an electric regulating valve, a second check valve, and an electromagnetic pressure relief valve. The exhaust end of the auxiliary air compressor is connected to the beginning end of the second pressure pipeline. The buffer tank, the second pressure transmitter, the electric regulating valve, and the second check valve are installed sequentially on the second pressure pipeline along the airflow direction. The inlet end of the electromagnetic pressure relief valve is connected to the second pressure pipeline on the inlet side of the electric regulating valve, and the outlet end of the electromagnetic pressure relief valve is connected to the second pressure pipeline on the outlet side of the electric regulating valve.

[0009] The gas storage module includes a third pressure pipeline, a gas storage tank, a fourth pressure pipeline, and a third pressure transmitter. The first end of the third pressure pipeline is connected to the end of the first pressure pipeline and the end of the second pressure pipeline, respectively. The end of the third pressure pipeline is connected to the inlet end of the gas storage tank. The outlet end of the gas storage tank is connected to the first end of the fourth pressure pipeline. The third pressure transmitter is installed on the fourth pressure pipeline.

[0010] The electrical control module includes an industrial computer, a PLC controller, a frequency converter, a main air compressor controller, and an auxiliary air compressor controller. The PLC controller is electrically connected to the industrial computer, the frequency converter, the main air compressor controller, the auxiliary air compressor controller, the first pressure transmitter, the second pressure transmitter, the electric regulating valve, the electromagnetic pressure relief valve, and the third pressure transmitter. The frequency converter is electrically connected to the main air compressor, the main air compressor controller is electrically connected to the main air compressor, and the auxiliary air compressor controller is electrically connected to the auxiliary air compressor.

[0011] Preferably, the main air compressor is a permanent magnet synchronous variable frequency screw air compressor, the auxiliary air compressor is a fixed frequency screw air compressor, and the sum of the rated discharge capacity of all auxiliary air compressors is greater than or equal to the rated discharge capacity of the main air compressor.

[0012] Preferably, the volume V of the buffer tank is related to the rated discharge capacity Q of the corresponding auxiliary air compressor. 辅 The buffer tank satisfies V=(0.15~0.25)Qauxiliary, the volume range of the buffer tank is 0.3m³-1m³, and the length-to-diameter ratio of the buffer tank is 1.5:1-3:1.

[0013] Preferably, the frequency adjustment range of the frequency converter is 15Hz-75Hz.

[0014] A control method for a multi-level coordinated gas supply system, based on a multi-level coordinated gas supply system, including a main gas supply mode and an auxiliary gas supply mode;

[0015] The control steps for the main gas supply mode are as follows: The PLC controller acquires the pressure value Pstore from the third pressure transmitter and compares it with the set value Pset. set In comparison, when |P 储 -P set ≤0.5%P set When the frequency converter maintains the current frequency, the inverter will maintain the current frequency; when 0.5%P set <|P 储 -P set |≤2%P set At that time, the PID algorithm is used to adjust the speed of the main air compressor; |P 储 -P set |>2%P set When the main air compressor frequency is ≥70Hz or lasts for 10 seconds, the auxiliary air supply mode is triggered.

[0016] The control steps for the auxiliary gas supply mode are as follows:

[0017] S1, Triggering Phase: Start the auxiliary air compressor to pressurize the buffer tank to P. 缓 ≥0.95P set When P 缓 >1.1P set The auxiliary air compressor must not be started at this time;

[0018] S2, Pre-synchronization Phase: When |P 缓 -P 储 When the pressure is ≤0.05MPa, open the electric regulating valve to 10% opening.

[0019] S3. Smooth grid connection stage: Based on the real-time pressure difference ΔP=P 辅 -P 主 The opening rate of the main dynamic regulating electric regulating valve is as follows: when ΔP≤0.03MPa, it opens at a rate of 15% per second; when 0.03MPa<ΔP≤0.05MPa, it opens at a rate of 5% per second; when ΔP>0.05MPa, it pauses opening and triggers the electromagnetic pressure relief valve.

[0020] S4. Exit Phase: When the main air compressor frequency stabilizes within ±5Hz of the target frequency and P... 储 If the fluctuation is ≤±1% for 5 minutes, turn off the auxiliary gas supply mode.

[0021] Preferably, the electromagnetic pressure relief valve is opened when the pressure difference ΔP between the second pressure pipeline and the first pressure pipeline is greater than 0.05 MPa and lasts for more than 2 seconds, and is closed when the pressure difference ΔP is less than or equal to 0.05 MPa.

[0022] Preferably, the sampling period of the first pressure transmitter, the second pressure transmitter, and the third pressure transmitter is dynamically adjusted according to the pressure change rate. When the pressure change rate dP / dt ≥ 0.1 MPa / s, the sampling period is 50 ms; when dP / dt < 0.1 MPa / s, the sampling period is 100 ms.

[0023] Preferably, when multiple sets of auxiliary gas supply modules are provided, each set of auxiliary gas supply modules is triggered to enter the network in sequence according to the pressure deviation. If the pressure still does not meet the requirements after a single set of auxiliary gas supply modules is put into operation, the next set of auxiliary gas supply modules is triggered to start.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This invention adopts a multi-level collaborative air supply architecture that combines a variable frequency main air source and a fixed frequency auxiliary air source, with a mode switching triggered on demand. Overall, the main air compressor is prioritized to operate in the optimal energy efficiency range, and the auxiliary unit supplements the air supply only when the load exceeds the limit. This avoids the long-term high-frequency full-load operation of a single device, which not only reduces the overall system energy consumption and delays the aging of core components, but also naturally forms a redundant air source configuration. This improves the shortcomings of traditional standby unit switching delay and inability to seamlessly connect, and enhances the continuity of air supply.

[0026] 2. This invention combines a buffer pressure stabilization structure with a progressive grid connection control, forming a complete pressure stabilization link from auxiliary gas source output to main grid connection and then to terminal gas storage output. It can first suppress the exhaust pulsation of the auxiliary gas source, then avoid airflow impact on the main grid through a controllable grid connection process, and finally the gas storage module further smooths out instantaneous load fluctuations. It weakens the transmission and superposition of pressure oscillations throughout the process, reduces the overall pipeline pressure fluctuation rate, avoids the surge risk of multi-machine parallel operation from the root, and ensures the operational stability of precision gas-using equipment.

[0027] 3. This invention adopts a dynamic sampling mechanism based on the pressure change rate, combined with graded threshold control logic and pre-synchronization grid connection process. It can automatically increase the sampling frequency under pressure change conditions, quickly capture pressure change characteristics and perform control, and reduce the sampling frequency when the pressure is stable to reduce system resource consumption. At the same time, with the control steps of pre-synchronization preparation and rate-based grid connection, the overall response time of the system to load fluctuations is shortened and the control accuracy is improved. Attached Figure Description

[0028] Figure 1 This is a flowchart of the main gas supply mode control logic of the present invention;

[0029] Figure 2 This is a flowchart of the auxiliary gas supply mode control logic of the present invention;

[0030] Figure 3 This is a schematic diagram of the overall structure of the present invention.

[0031] In the diagram: 101, main air compressor; 102, first pressure pipeline; 103, first check valve; 104, first pressure transmitter; 201, auxiliary air compressor; 202, second pressure pipeline; 203, buffer tank; 204, second pressure transmitter; 205, electric regulating valve; 206, second check valve; 207, electromagnetic pressure relief valve; 301, third pressure pipeline; 302, air tank; 303, fourth pressure pipeline; 304, third pressure transmitter; 401, industrial computer; 402, PLC controller; 403, frequency converter; 404, main air compressor controller; 405, auxiliary air compressor controller. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] To address the issues of low energy efficiency, large pressure fluctuations, slow response, and poor redundancy in existing gas supply systems, please refer to [link / reference]. Figure 1-3 This embodiment provides the following technical solution:

[0034] A multi-level coordinated gas supply system consists of a main gas supply module, at least one auxiliary gas supply module, a gas storage module, and an electrical control module.

[0035] The main air supply module is formed by connecting the main air compressor 101 to the first check valve 103 and the first pressure transmitter 104 in sequence through the first pressure pipeline 102.

[0036] The main air compressor 101 adopts a permanent magnet synchronous variable frequency screw air compressor. Under normal operating conditions, only the main air compressor 101 is started to supply air to the air storage module. The selection of the main air compressor 101 can be based on the air consumption of the terminal. The variable frequency speed regulation is used to match the air demand of the terminal in real time, thereby minimizing energy consumption.

[0037] The variable frequency speed regulation range of the main air compressor 101 is 15-75Hz, which is set based on the working efficiency and service life of the equipment. When the target frequency reaches 70Hz, if the system pressure is still lower than the set value, the auxiliary air supply module will be automatically triggered.

[0038] The first pressure pipeline 102 is used to sequentially connect the components in the main air supply module, and its diameter meets the flow rate requirements of the main air compressor 101. The first check valve 103 is used to prevent backflow of downstream airflow into the main air compressor 101. The first pressure transmitter 104 is used to collect the real-time air pressure of the first pressure pipeline 102.

[0039] The auxiliary air supply module consists of an auxiliary air compressor 201 connected in sequence to a buffer tank 203, a second pressure transmitter 204, an electric regulating valve 205, and a second check valve 206 via a second pressure pipeline 202. An electromagnetic pressure relief valve 207 is connected in parallel with the electric regulating valve 205.

[0040] Auxiliary air compressor 201 is a fixed-frequency screw air compressor, serving as a supplementary air source for the main air supply module. It starts in case of sudden changes in load demand or failure of the main air supply module. The power of auxiliary air compressor 201 can be equal to or less than that of main air compressor 101, but the discharge volume must meet ΣQ. 辅 ≥Q 主 .

[0041] The second pressure pipe 202 is used to sequentially connect the components in the auxiliary air supply module, and its diameter meets the flow rate requirements of the auxiliary air compressor 201. The buffer tank 203 is used to buffer the exhaust pressure fluctuations of the auxiliary air compressor 201 and the uneven flow rate of the second pressure pipe 202; the volume V of the buffer tank 203 is designed proportionally to the exhaust volume Q of the auxiliary air compressor 201, satisfying V = (0.15~0.25)Q. 辅 Q 辅The exhaust volume at rated pressure is expressed in m³ / min, which can effectively suppress airflow pulsation and achieve pressure balance in conjunction with the gradual opening strategy of the electric regulating valve 205; at the same time, the volume is limited to 0.3-1m³ to avoid airflow pulsation transmission caused by small volume or response delay caused by large volume; the length-to-diameter ratio is 1.5:1-3:1, which can take into account both pressure buffering and installation stability.

[0042] The second pressure transmitter 204 is used to collect the real-time pressure of the second pressure pipeline 202. The electric regulating valve 205, in conjunction with PID control, achieves gradual opening and balanced grid connection. The second check valve 206 prevents backflow of downstream airflow into the auxiliary air compressor 201. The electromagnetic pressure relief valve 207 prevents the pressure in the second pressure pipeline 202 from exceeding the set threshold of the first pressure pipeline 102, automatically releasing pressure; the trigger condition for the electromagnetic pressure relief valve 207 is: when the pressure Pauxiliary in the second pressure pipeline equals the pressure Pauxiliary in the first pressure pipeline. 主 The system opens when the pressure difference ΔP > 0.05 MPa and lasts for more than 2 seconds, and closes when ΔP ≤ 0.05 MPa. At least one auxiliary gas supply module is provided, with all modules connected in parallel and connected to the third pressure pipeline 301.

[0043] The gas storage module is connected to the confluence of the first pressure pipeline 102 and the second pressure pipeline 202 via a third pressure pipeline 301. The end of the third pressure pipeline 301 is connected to the inlet of the gas storage tank 302, and the outlet of the gas storage tank 302 is sequentially connected to a fourth pressure pipeline 303 and a third pressure transmitter 304. The third pressure pipeline 301 is connected to the ends of the first pressure pipeline 102 and the second pressure pipeline 202 respectively, introducing gas into the gas storage tank 302 for storage. The pipe diameter meets the gas flow rate requirements of the main air compressor 101 and the auxiliary air compressor 201 simultaneously. The volume of the gas storage tank 302 is determined based on the gas consumption of the end user; when the end user gas consumption is large, multiple gas storage tanks can be connected in parallel to increase the gas storage capacity. The fourth pressure pipeline 303 delivers compressed gas to the gas user. The third pressure transmitter 304 is used to collect the real-time pressure of the gas storage tank 302.

[0044] The electrical control module includes an industrial computer 401 and a PLC controller 402. The electrical control module coordinates and controls the following via the PLC controller 402: the frequency converter 403 of the main air compressor 101, the main air compressor controller 404, the auxiliary air compressor controller 405, the opening degree of the electric regulating valve 205, and the triggering conditions of the solenoid pressure relief valve 207. The PLC controller 402 can connect to each actuator via a PROFIBUS-DP bus.

[0045] The first pressure transmitter 104, the second pressure transmitter 204, and the third pressure transmitter 304 are 4-20mA output type pressure transmitters with an accuracy of 0.5 class. They dynamically adjust the sampling period by calculating the pressure change rate dP / dt in real time. When the pressure fluctuation is large, i.e., dP / dt≥0.1MPa / s, a high-frequency sampling period of t=50ms is used; when the pressure is stable, i.e., dP / dt<0.1MPa / s, a low-frequency sampling period of t=100ms is used to reduce system resource consumption.

[0046] The control process of the multi-level coordinated gas supply system of this invention is divided into main gas supply mode and auxiliary gas supply mode. Under normal operating conditions, the system operates in main gas supply mode. The PLC controller 402 receives real-time feedback data from the third pressure transmitter 304 and compares the collected pressure value Pstore with the set value Pset.

[0047] When |P 储 -P set ≤0.5%P set At this time, inverter 403 maintains the current frequency to avoid frequent adjustments;

[0048] When 0.5% P set <|P 储 -P set |≤2%P set At that time, the PID algorithm is used to finely adjust the speed of the main air compressor 101 in real time;

[0049] When |P 储 -P set |>2%P set If the main air compressor frequency is ≥70Hz for 10 seconds or longer, the system will automatically trigger the auxiliary air supply module and switch to the auxiliary air supply mode.

[0050] The auxiliary gas supply mode operates in four stages:

[0051] During the triggering phase, the auxiliary air compressor 201 is started to pressurize the buffer tank 203 until the buffer tank pressure P is reached. 缓 ≥0.95P set When P 缓 >1.1P set Auxiliary air compressor 201 must not be started at this time to avoid the risk of overpressure.

[0052] During the pre-synchronization phase, the pressure of the buffer tank and the gas storage tank are compared in real time. When |P 缓 -P 储 When the pressure is ≤0.05MPa, pre-open the electric regulating valve to 205 to 10% of its opening to prepare for gas source grid connection;

[0053] During the smooth grid connection phase, based on the real-time pressure difference ΔP=P 辅 -P 主The valve opening rate is dynamically adjusted. When ΔP ≤ 0.03MPa, it opens rapidly at a rate of 15% per second to shorten the response time; when 0.03MPa < ΔP ≤ 0.05MPa, it opens slowly at a rate of 5% per second to avoid pressure shock; when ΔP > 0.05MPa, the opening is paused and the electromagnetic pressure relief valve 207 is triggered for forced pressure relief protection.

[0054] When the system operation status meets the exit conditions, that is, when the frequency of the main air compressor 101 is stable within the target frequency ±5Hz and the pressure fluctuation of the air tank is ≤±1% for 5 minutes, the PLC controller 402 shuts down the auxiliary air compressor 201 and the electric regulating valve 205, and the system switches back to the main air supply mode.

[0055] Working principle: Under normal operating conditions, the system operates in the main air supply mode. The compressed gas generated by the main air compressor 101 is transported along the first pressure pipeline 102. After passing through the first check valve 103, the pipeline pressure is collected by the first pressure transmitter 104. Then it flows into the third pressure pipeline 301 and is sent to the air storage tank 302 to complete pressure stabilization and storage. Finally, it is supplied to the gas-using terminal through the fourth pressure pipeline 303.

[0056] The third pressure transmitter 304 collects the outlet pressure of the gas storage tank in real time and feeds it back to the PLC controller 402. The PLC controller 402 dynamically adjusts the speed of the main air compressor 101 through the frequency converter 403 to match the real-time gas demand of the terminal. When the main gas supply mode cannot meet the pressure requirements, the system switches to the auxiliary gas supply mode. The auxiliary air compressor controller 405 drives the auxiliary air compressor 201 to start. The gas enters the buffer tank 203 along the second pressure pipeline 202 to suppress airflow pulsation. The second pressure transmitter 204 collects the branch pressure in real time. The electric regulating valve 205 adjusts the opening rate according to the pressure difference between the main and auxiliary branches to achieve stable grid connection of the auxiliary gas source. The second check valve 206 prevents backflow of airflow. When the pressure difference exceeds the limit, the electromagnetic pressure relief valve 207 automatically opens to relieve pressure.

[0057] The industrial computer 401 is responsible for setting system parameters and monitoring operating status. The main air compressor controller 404 cooperates to execute the main unit operation control. After the load drops and meets the exit conditions, the auxiliary module is shut down and the system resumes single main air supply operation.

[0058] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A multi-stage coordinated gas supply system, characterized in that, It includes a main gas supply module, at least one auxiliary gas supply module, a gas storage module, and an electrical control module; The main air supply module includes a main air compressor (101), a first pressure pipeline (102), a first check valve (103), and a first pressure transmitter (104). The exhaust end of the main air compressor (101) is connected to the beginning end of the first pressure pipeline (102). The first check valve (103) and the first pressure transmitter (104) are installed sequentially on the first pressure pipeline (102) along the airflow direction. The auxiliary air supply module includes an auxiliary air compressor (201), a second pressure pipeline (202), a buffer tank (203), a second pressure transmitter (204), an electric regulating valve (205), a second check valve (206), and an electromagnetic pressure relief valve (207). The exhaust end of the auxiliary air compressor (201) is connected to the beginning end of the second pressure pipeline (202). The buffer tank (203), the second pressure transmitter (204), the electric regulating valve (205), and the second check valve (206) are installed sequentially on the second pressure pipeline (202) along the airflow direction. The inlet end of the electromagnetic pressure relief valve (207) is connected to the second pressure pipeline (202) on the inlet side of the electric regulating valve (205), and the outlet end of the electromagnetic pressure relief valve (207) is connected to the second pressure pipeline (202) on the outlet side of the electric regulating valve (205). The gas storage module includes a third pressure pipeline (301), a gas storage tank (302), a fourth pressure pipeline (303), and a third pressure transmitter (304). The first end of the third pressure pipeline (301) is connected to the end of the first pressure pipeline (102) and the end of the second pressure pipeline (202), respectively. The end of the third pressure pipeline (301) is connected to the inlet end of the gas storage tank (302). The outlet end of the gas storage tank (302) is connected to the first end of the fourth pressure pipeline (303). The third pressure transmitter (304) is installed on the fourth pressure pipeline (303). The electrical control module includes an industrial computer (401), a PLC controller (402), a frequency converter (403), a main air compressor controller (404), and an auxiliary air compressor controller (405). The PLC controller (402) is electrically connected to the industrial computer (401), the frequency converter (403), the main air compressor controller (404), the auxiliary air compressor controller (405), the first pressure transmitter (104), the second pressure transmitter (204), the electric regulating valve (205), the electromagnetic pressure relief valve (207), and the third pressure transmitter (304), respectively. The frequency converter (403) is electrically connected to the main air compressor (101), the main air compressor controller (404) is electrically connected to the main air compressor (101), and the auxiliary air compressor controller (405) is electrically connected to the auxiliary air compressor (201).

2. The multi-stage coordinated gas supply system according to claim 1, characterized in that, The main air compressor (101) is a permanent magnet synchronous variable frequency screw air compressor, and the auxiliary air compressor (201) is a fixed frequency screw air compressor. The sum of the rated discharge capacity of all auxiliary air compressors (201) is greater than or equal to the rated discharge capacity of the main air compressor (101).

3. The multi-stage coordinated gas supply system according to claim 1, characterized in that, The volume V of the buffer tank (203) is related to the rated discharge capacity Q of the corresponding auxiliary air compressor (201). 辅 Satisfying V = (0.15 ~ 0.25)Q 辅 The volume of the buffer tank (203) ranges from 0.3m³ to 1m³, and the length-to-diameter ratio of the buffer tank (203) is 1.5:1 to 3:

1.

4. The multi-stage coordinated gas supply system according to claim 1, characterized in that, The frequency conversion range of the inverter (403) is 15Hz-75Hz.

5. The control method for a multi-level coordinated gas supply system according to claim 1, characterized in that, The sampling period of the first pressure transmitter (104), the second pressure transmitter (204), and the third pressure transmitter (304) is dynamically adjusted according to the pressure change rate. When the pressure change rate dP / dt ≥ 0.1 MPa / s, the sampling period is 50 ms; when dP / dt < 0.1 MPa / s, the sampling period is 100 ms.

6. A control method for a multi-stage coordinated gas supply system, implemented based on the multi-stage coordinated gas supply system according to any one of claims 1-5, characterized in that, Including main gas supply mode and auxiliary gas supply mode; The control steps for the main gas supply mode are as follows: The PLC controller (402) acquires the pressure value Pstore from the third pressure transmitter (304) and compares it with the set value Pset. set In comparison, when |P 储 -P set ≤0.5%P set When the frequency converter (403) maintains the current frequency, when 0.5%P set <|P 储 -P set |≤2%P set At that time, the PID algorithm is used to adjust the speed of the main air compressor (101); |P 储 -P set |>2%P set When the main air compressor (101) frequency is ≥70Hz for 10 seconds, the auxiliary air supply mode is triggered. The control steps for the auxiliary gas supply mode are as follows: S1, Triggering stage: Start the auxiliary air compressor (201) to pressurize the buffer tank (203) to P. 缓 ≥0.95P set When P 缓 >1.1P set The auxiliary air compressor must not be started at this time (201); S2, Pre-synchronization Phase: When |P 缓 -P 储 When the pressure is ≤0.05MPa, open the electric regulating valve (205) to 10% opening; S3. Smooth grid connection stage: Based on the real-time pressure difference ΔP=P 辅 -P 主 The opening rate of the main dynamic regulating electric regulating valve (205) is as follows: when ΔP≤0.03MPa, it opens at a rate of 15% per second; when 0.03MPa<ΔP≤0.05MPa, it opens at a rate of 5% per second; when ΔP>0.05MPa, it pauses opening and triggers the electromagnetic pressure relief valve (207). S4, Exit Phase: When the frequency of the main air compressor (101) stabilizes within the target frequency ±5Hz and P 储 If the fluctuation is ≤±1% for 5 minutes, turn off the auxiliary gas supply mode.

7. The control method for a multi-level coordinated gas supply system according to claim 6, characterized in that, The electromagnetic pressure relief valve (207) is opened when the pressure difference between the second pressure pipeline and the first pressure pipeline is greater than 0.05 MPa and lasts for more than 2 seconds, and is closed when the pressure difference is less than or equal to 0.05 MPa.

8. The control method for a multi-level coordinated gas supply system according to claim 6, characterized in that, When multiple sets of the auxiliary gas supply module are set, each set of auxiliary gas supply module is triggered to enter the network in sequence according to the pressure deviation. If the pressure still does not meet the requirements after a single set of auxiliary gas supply module is put into operation, the next set of auxiliary gas supply module is triggered to start.

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