Pressure flow regulating system of explosion-proof positive pressure cabinet

Abstract

The utility model provides a kind of pressure flow regulating system of explosion-proof positive pressure cabinet, including electric regulating valve, pressure sensor, flow sensor and controller;External high-pressure gas is input into explosion-proof positive pressure cabinet after being adjusted by electric regulating valve;Pressure sensor is arranged in explosion-proof positive pressure cabinet, and flow sensor is arranged at the air inlet of explosion-proof positive pressure cabinet;Controller includes first PID module and second PID module;Pressure sensor is electrically connected with the PV input port of first PID module, the output port of first PID module is electrically connected with the SP input port of second PID module, flow sensor is electrically connected with the PV input port of second PID module, and the output port of second PID module is electrically connected with electric regulating valve;Electric regulating valve is used to carry out opening degree adjustment according to the control signal output by second PID module.The utility model can quickly respond to the flow fluctuation caused by gas source, suppress the pressure fluctuation of explosion-proof positive pressure cabinet by quickly adjusting flow, and ensure pressure stability.

Description

Technical Field

[0001] This utility model belongs to the field of positive pressure cabinet technology, specifically relating to a pressure and flow regulation system for an explosion-proof positive pressure cabinet. Background Technology

[0002] An explosion-proof positive pressure cabinet is a device specifically designed for operation in explosive gas or dust environments. Through a pressure control system, the cabinet introduces clean and safe compressed air into the positive pressure chamber, maintaining internal positive pressure to prevent the entry of hazardous gases and dust from the outside, thus achieving explosion protection.

[0003] The safe operation of explosion-proof positive pressure cabinets requires maintaining internal pressure. Therefore, existing pressure control systems for explosion-proof positive pressure cabinets mostly regulate the air intake flow by detecting the internal pressure, such as using electrically controlled valves and pressure sensors. The opening of the electrically controlled valve is adjusted based on the internal pressure detected by the pressure sensor. When the gas source pressure or flow rate fluctuates, it will affect the gas flow rate into the cabinet, thereby changing the internal pressure. Because gas is compressible, pressure changes lag significantly behind flow rate changes. Therefore, existing pressure control systems have slow response speeds and are prone to causing unstable internal pressure. Utility Model Content

[0004] This invention addresses the shortcomings of existing technologies by providing a pressure and flow regulation system for an explosion-proof positive pressure cabinet.

[0005] To solve one, some, or all of the above-mentioned technical problems, the technical solution adopted by this utility model is: A pressure and flow regulation system for an explosion-proof positive pressure cabinet includes an electric regulating valve, a pressure sensor, a flow sensor, and a controller. External high-pressure gas is regulated by the electric regulating valve and then input into the explosion-proof positive pressure cabinet. The pressure sensor is located inside the explosion-proof positive pressure cabinet, and the flow sensor is located at the air inlet of the cabinet. The controller includes a first PID module and a second PID module. The pressure sensor is electrically connected to the PV input port of the first PID module, the output port of the first PID module is electrically connected to the SP input port of the second PID module, the flow sensor is electrically connected to the PV input port of the second PID module, and the output port of the second PID module is electrically connected to the electric regulating valve. The electric regulating valve is used to adjust its opening degree according to the control signal output by the second PID module.

[0006] Furthermore, it also includes a pressure-reducing filter valve; the pressure-reducing filter valve is connected to an external high-pressure gas source through a gas source interface and delivers the filtered gas to the electric regulating valve.

[0007] Furthermore, the high-pressure gas is an inert gas or clean air.

[0008] Furthermore, the explosion-proof positive pressure cabinet is a Px type explosion-proof positive pressure cabinet, the electric regulating valve, the pressure sensor and the flow sensor are all explosion-proof products, the controller is located in a safe area, and the electric regulating valve is equipped with an explosion-proof housing.

[0009] Furthermore, the controller is a C3100 / C4100 series controller.

[0010] Furthermore, the electric regulating valve is a flow-controlled regulating valve.

[0011] Furthermore, the electric regulating valve is an APU series positive pressure flow control type regulating valve, and it is housed in an explosion-proof housing.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows: The second PID module of this invention adjusts the opening of the electric regulating valve based on the actual gas flow rate and the target flow rate. The flow sensor can detect flow rate changes caused by gas source fluctuations in real time. Therefore, the second PID module can quickly adjust the electric regulating valve to stabilize the flow rate before flow fluctuations significantly affect the pressure inside the cabinet, resulting in a rapid response. The first PID module determines the target flow rate value based on the actual and target pressure values ​​inside the cabinet and provides it to the second PID module, ensuring that the goal of the second PID module in regulating flow is to maintain pressure stability.

[0013] This invention can quickly respond to flow fluctuations caused by the gas source and suppress pressure fluctuations in the explosion-proof positive pressure cabinet by rapidly adjusting the flow rate, thus ensuring pressure stability. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings.

[0015] Figure 1 : A schematic diagram of this utility model; Figure 2 : A schematic diagram of the signal flow of this utility model; Among them: 1-Gas source interface, 2-Pressure reducing filter valve, 3-Electric regulating valve, 4-Pressure sensor, 5-Flow sensor, 6-Controller, 61-First PID module, 62-Second PID module, 8-Explosion-proof positive pressure cabinet. Detailed Implementation

[0016] To better understand this utility model, the content of this utility model is further explained clearly below with reference to the embodiments and accompanying drawings. However, the protection scope of this utility model is not limited to the embodiments described below. Numerous specific details are set forth in the following description to provide a more thorough understanding of this utility model. However, it will be apparent to those skilled in the art that this utility model can be practiced without one or more of these details.

[0017] Example 1: See Figures 1-2 The purpose of this embodiment is to provide a pressure and flow regulation system for an explosion-proof positive pressure cabinet. It includes a pressure reducing filter valve 2, an electric regulating valve 3, a pressure sensor 4, a flow sensor 5, and a controller 6. The pressure reducing filter valve 2 is connected to an external high-pressure gas source via a gas source interface 1. The high-pressure gas output from the pressure reducing filter valve 2 is regulated by the electric regulating valve 3 and then input into the positive pressure chamber of the explosion-proof positive pressure cabinet 8. The pressure sensor 4 is installed inside the positive pressure chamber of the explosion-proof positive pressure cabinet 8 to acquire internal gas pressure data. The flow sensor 5 is installed at the air inlet of the explosion-proof positive pressure cabinet 8 to acquire gas flow data. Both the pressure sensor 4 and the flow sensor 5 are electrically connected to the controller 6, transmitting pressure and flow signals to the controller 6.

[0018] The external high-pressure gas source is inert gas or clean air. The pressure reducing filter valve 2 is used to filter water vapor that may be present in the gas source, providing a clean gas source for subsequent pipelines.

[0019] The controller 6 is electrically connected to the electric regulating valve 3. It generates control signals based on pressure and flow signals and sends these signals to the electric regulating valve 3 to adjust its opening, thereby stabilizing the pressure inside the positive pressure cabinet. Specifically, the controller 6 includes a first PID module 61 and a second PID module 62. The pressure sensor 4 is electrically connected to the PV input port of the first PID module 61, the output port of the first PID module 61 is electrically connected to the SP input port of the second PID module 62, and the flow sensor 5 is electrically connected to the PV input port of the second PID module 62. The output port of the second PID module 62 is electrically connected to the electric regulating valve 3.

[0020] It should be noted that the PV input port of the PID module is used to input the target signal, and the SP input port is used to input the real-time signal. Both the first PID module 61 and the second PID module 62 are tuned.

[0021] like Figure 2As shown, the first PID module 61 targets the pressure value required for the normal operation of the explosion-proof positive pressure cabinet 8 (this pressure value is stored in the memory chip of the controller 6), uses the actual pressure value detected by the pressure sensor 4 as the current value, and outputs a control signal as the target flow rate value. The second PID module 62 targets the target flow rate value output by the first PID module 61, uses the actual flow rate value detected by the flow sensor 5 as the current value, and outputs a control signal for the electric regulating valve 3.

[0022] The controller 6 uses a controller product with two PID control modules (corresponding to the first PID module 61 and the second PID module 62). For example, the C3100 / C4100 series controller from Supcon Technology Co., Ltd., such as the specific model C3100-02-A0-C4-PL1-PID2-24VDC / SCH (2 PID modules, 2 channels of analog 4-20mA input, RS-485 communication interface, 24VDC power supply).

[0023] Electric regulating valve 3 uses a flow control type regulating valve. For example, the positive pressure flow control type regulating valve of the APU series from Nagano Fukuda (Tianjin) Instrument Co., Ltd., such as the specific model APU-508W-PF-2 (positive pressure flow control type, pressure range ±2kPa).

[0024] Example 2: The pressure and flow regulation system of the explosion-proof positive pressure cabinet provided in this example has the following main improvements compared with Example 1: The explosion-proof positive pressure cabinet 8 is a Px type explosion-proof positive pressure cabinet. The electric regulating valve 3, pressure sensor 4 and flow sensor 5 are all explosion-proof products. The controller 6 is located in the safe area, and the electric regulating valve 3 is equipped with an explosion-proof housing.

[0025] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solution of this utility model, as long as they do not depart from the spirit and scope of the technical solution of this utility model, should be covered within the scope of the claims of this utility model.

Claims

1. A pressure and flow regulation system for an explosion-proof positive pressure cabinet, characterized in that, Includes electric regulating valves, pressure sensors, flow sensors, and controllers; External high-pressure gas is introduced into the explosion-proof positive pressure cabinet after being regulated by the electric regulating valve. The pressure sensor is installed inside the explosion-proof positive pressure cabinet, and the flow sensor is installed at the air inlet of the explosion-proof positive pressure cabinet. The controller includes a first PID module and a second PID module; the pressure sensor is electrically connected to the PV input port of the first PID module, the output port of the first PID module is electrically connected to the SP input port of the second PID module, the flow sensor is electrically connected to the PV input port of the second PID module, and the output port of the second PID module is electrically connected to the electric regulating valve; the electric regulating valve is used to adjust its opening degree according to the control signal output by the second PID module.

2. The pressure and flow regulation system for the explosion-proof positive pressure cabinet according to claim 1, characterized in that, It also includes a pressure reducing filter valve; the pressure reducing filter valve is connected to an external high-pressure gas source through a gas source interface and delivers the filtered gas to the electric regulating valve.

3. The pressure and flow regulation system for the explosion-proof positive pressure cabinet according to claim 1, characterized in that, The high-pressure gas is either an inert gas or clean air.

4. The pressure and flow regulation system for the explosion-proof positive pressure cabinet according to claim 1, characterized in that, The explosion-proof positive pressure cabinet is a Px type explosion-proof positive pressure cabinet. The electric regulating valve, the pressure sensor and the flow sensor are all explosion-proof products. The controller is located in a safe area, and the electric regulating valve is equipped with an explosion-proof housing.

5. The pressure and flow regulation system for the explosion-proof positive pressure cabinet according to claim 1, characterized in that, The controller is a C3100 / C4100 series controller.

6. The pressure and flow regulation system for the explosion-proof positive pressure cabinet according to claim 1, characterized in that, The electric regulating valve is a flow control type regulating valve.

7. The pressure and flow regulation system for the explosion-proof positive pressure cabinet according to claim 6, characterized in that, The electric regulating valve is an APU series positive pressure flow control type regulating valve, and it is housed in an explosion-proof enclosure.

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