Intelligent anti-explosion positive pressure control system and pressure control method

Abstract

The invention belongs to the technical field of pressure control, and mainly relates to an intelligent anti-explosion positive pressure control system and a pressure control method.The control system comprises a positive pressure cabinet, and the air inlet end of an air channel of the positive pressure cabinet is sequentially communicated with a throttling valve, a pressure reduction filter valve, a first valve and an air source connector; an explosion-proof high-pressure differential pressure switch, an explosion-proof low-pressure differential pressure switch and a pressure gauge are respectively communicated with a gas path of the positive pressure cabinet; the pressure reduction filter valve is communicated with an anti-explosion air supply electromagnetic valve; the anti-explosion air supply electromagnetic valve is communicated with the air inlet end of the positive pressure cabinet air path; and the gas outlet end of the positive pressure cabinet gas circuit is communicated with an anti-explosion exhaust electromagnetic valve. When the explosion-proof low-pressure differential pressure switch detects that the pressure reaches a low-pressure set value, the explosion-proof air supply electromagnetic valve automatically starts to work, and the air inlet amount is increased to supply air into the cabinet; when the explosion-proof high-pressure differential pressure switch detects that the pressure is higher than a high-pressure set value, the explosion-proof exhaust electromagnetic valve can automatically start to work, the gas displacement is increased to exhaust gas in the cabinet, manual operation of workers is avoided, the labor intensity is reduced, and the efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure control, and mainly relates to an intelligent explosion-proof positive pressure control system and a pressure control method. Background Art

[0002] In petrochemical and other manufacturing enterprises, the working environment contains high levels of volatile gases such as flammable and explosive gases. Once these gases come into contact with sparks, flash explosions are very likely to occur. Therefore, equipment that generates sparks should be avoided as much as possible in the production workshop. However, due to production requirements, some control cabinets must be installed in dangerous areas of these explosive gas environments.

[0003] In the prior art, explosion-proof positive pressure cabinets are often used to replace control cabinets. Explosion-proof positive pressure cabinets are widely used in special working places such as explosion-proof, petrochemical, air conditioning and refrigeration, textile and pharmaceutical industries. However, the gas circuit design of explosion-proof positive pressure cabinets is often composed of air pipes, mechanical hand valves, etc. Once the gas source fluctuates and the pressure in the cabinet drops, on-site personnel need to manually adjust it, which is extremely inconvenient. Summary of the invention

[0004] The present invention provides an intelligent explosion-proof positive pressure control system and a pressure control method to solve the problem in the prior art that pressure changes in a cabinet require manual adjustment by staff.

[0005] To solve the above problems, the present invention adopts the following technical solutions: An intelligent explosion-proof positive pressure control system comprises a positive pressure cabinet, wherein the air inlet end of the air circuit of the positive pressure cabinet is sequentially connected with a throttle valve, a pressure reducing filter valve, a first valve and an air source interface; The gas path of the positive pressure cabinet is respectively connected with an explosion-proof high-pressure differential pressure switch, an explosion-proof low-pressure differential pressure switch and a pressure gauge, wherein the explosion-proof high-pressure differential pressure switch is used to set the high-pressure setting value of the positive pressure cabinet, the explosion-proof low-pressure differential pressure switch is used to set the low-pressure setting value of the positive pressure cabinet, and the pressure gauge is used to display the pressure in the positive pressure cabinet; The pressure reducing filter valve is connected to an explosion-proof air supply solenoid valve, which is connected to the air inlet end of the positive pressure cabinet gas circuit, so that the explosion-proof air supply solenoid valve and the throttle valve are arranged in parallel. When the pressure in the positive pressure cabinet is lower than the low pressure setting value, the explosion-proof air supply solenoid valve is opened to supply air to the positive pressure cabinet; The gas outlet end of the positive pressure cabinet gas circuit is connected with an explosion-proof exhaust solenoid valve. When the pressure in the positive pressure cabinet is higher than the high pressure setting value, the explosion-proof exhaust solenoid valve is opened to exhaust the positive pressure cabinet.

[0006] It has the following beneficial effects: when the explosion-proof low-pressure differential pressure switch detects that the pressure in the positive pressure cabinet has reached the low-pressure setting value, the explosion-proof air supply solenoid valve will automatically start working, increase the air intake to supply air to the cabinet until the air pressure meets the positive pressure setting value; when the explosion-proof high-pressure differential pressure switch detects that the pressure in the positive pressure cabinet is higher than the high-pressure setting value, the explosion-proof exhaust solenoid valve will automatically start working, increase the exhaust volume to exhaust the cabinet until the air pressure meets the positive pressure setting value. It runs continuously and stably, avoids manual operation by staff, reduces labor intensity, improves efficiency, and ensures stable system operation.

[0007] Furthermore, the gas outlet end of the positive pressure cabinet gas circuit is connected to a second valve, so that the second valve and the explosion-proof exhaust solenoid valve are arranged in parallel.

[0008] The invention has the following beneficial effects: the second valve and the explosion-proof exhaust solenoid valve can work in parallel at the same time.

[0009] Furthermore, the gas outlet ends of the second valve and the explosion-proof exhaust solenoid valve are provided with fire-blocking plates to limit the discharge of hazardous substances.

[0010] The fire barrier has the following beneficial effects: the fire barrier can effectively prevent flames or hot particles from entering the dangerous area.

[0011] Furthermore, the gas source interface is connected to a gas supply device, and the gas supply device is used to provide inert gas or air to the gas source interface.

[0012] The invention has the following beneficial effects: the gas supply equipment can ensure the normal pressure in the positive pressure cabinet.

[0013] Furthermore, an air circuit is provided in the positive pressure cabinet, and the air circuit has an air inlet end and an air outlet end.

[0014] Furthermore, the first valve and the second valve are both manual valves.

[0015] Furthermore, the first valve and the second valve are both electric valves.

[0016] The invention has the following beneficial effects: the electric valve can be remotely controlled, thus avoiding manual operation by the staff and reducing the workload.

[0017] Furthermore, the explosion-proof air supply solenoid valve, the explosion-proof exhaust solenoid valve, the first valve, the second valve, the explosion-proof high-pressure differential pressure switch and the explosion-proof low-pressure differential pressure switch are all electrically connected to a controller.

[0018] The invention has the following beneficial effects: the controller can control various components, thus reducing the labor of manual operation and improving efficiency.

[0019] The intelligent explosion-proof positive pressure control method comprises the following steps: connecting the gas source interface, opening the first valve, adjusting the pressure reducing filter valve and the throttle valve to provide positive pressure for the positive pressure cabinet; setting the low pressure and high pressure setting values, so that the positive pressure cabinet maintains positive pressure to the outside and meets the explosion-proof standard requirements; When the explosion-proof low-pressure differential pressure switch detects that the pressure in the positive pressure cabinet reaches the low-pressure setting value, the explosion-proof air supply solenoid valve works to increase the air intake to supply air to the cabinet until the air pressure meets the positive pressure setting value; When the explosion-proof high-pressure differential pressure switch detects that the pressure in the positive pressure cabinet is higher than the high-pressure setting value, the explosion-proof exhaust solenoid valve will work, increase the exhaust volume to exhaust the cabinet until the air pressure meets the positive pressure setting value, and operate continuously and stably.

[0020] The invention has the following beneficial effects: manual operation is avoided and efficiency is improved.

[0021] Furthermore, when the positive pressure of the positive pressure cabinet is no longer controlled, the second valve can be opened to release the pressure in the positive pressure cabinet. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood. In the accompanying drawings, several embodiments of the present invention are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 It is a structural schematic diagram of the present invention.

[0023] Description of reference numerals: 1. Gas source interface; 2. First valve; 3. Pressure reducing filter valve; 4. Throttle valve; 5. Explosion-proof high-pressure differential pressure switch; 6. Explosion-proof low-pressure differential pressure switch; 7. Pressure gauge; 8. Air pipe; 9. Explosion-proof air supply solenoid valve; 10. Explosion-proof exhaust solenoid valve; 11. Fire barrier; 12. Positive pressure cabinet; 13. Second valve. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0025] Various non-limiting embodiments of the present invention are described in detail below. Any number of elements in the accompanying drawings is for illustration and not for limitation, and any naming is only for distinction and does not have any limiting meaning. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0026] Control system embodiment like Figure 1 As shown, the intelligent explosion-proof positive pressure control system includes a positive pressure cabinet 12, in which an air circuit is provided, and the air circuit has an air inlet end and an air outlet end. The air inlet end of the air circuit of the positive pressure cabinet 12 is connected to a throttle valve 4, a pressure reducing filter valve 3, a first valve 2 and an air source interface 1 in sequence, and these components are connected through an air pipe 8. The air source interface 1 is connected to an air supply device, which is used to provide an inert gas or air to the air source interface 1. The air supply device provides gas to ensure the normal pressure in the positive pressure cabinet 12. The gas provided by the gas supply device enters from the air source interface 1, and then passes through the first valve 2, the pressure reducing filter valve 3 and the throttle valve 4 in sequence, and finally enters the air circuit in the positive pressure cabinet 12 to provide positive pressure for the positive pressure cabinet 12.

[0027] In this embodiment, the inert gas is nitrogen.

[0028] In other embodiments, the inert gas is argon or helium.

[0029] In this embodiment, the pressure reducing filter valve 3 is a valve device that combines pressure reducing and filtering functions, and is widely used in industrial production, laboratories, and some specific civilian scenarios. The following is an introduction from three aspects: structure, principle, and application: Structure: The pressure reducing filter valve 3 consists of the valve body, valve core, valve seat, spring, filter screen and other main components. The valve body is the outer shell of the valve, which supports and protects the internal components. The valve core and valve seat cooperate to control the on-off and flow rate of the fluid. The spring provides pressure so that the valve core can maintain a stable position under different working conditions. The filter screen is generally installed at the inlet of the valve to intercept impurities in the fluid.

[0030] Working principle: ① Pressure reduction principle: When high-pressure fluid enters the valve, the throttling effect between the valve core and the valve seat reduces the pressure of the fluid to the set value. The elastic force of the spring can be adjusted as needed to change the position of the valve core, thereby achieving precise control of the outlet pressure. ② Filtration principle: When the fluid enters the valve, it first passes through the filter. The filter can effectively intercept solid particles, impurities, etc. in the fluid, making the fluid passing through the valve purer and achieving the purpose of filtration.

[0031] Application scenarios: ①Industrial field: In the chemical, petroleum, electric power and other industries, the pressure reducing filter valve 3 can be used to reduce pressure and filter various fluids (such as steam, liquid, gas, etc.) to meet the requirements of the production process. For example, in chemical production, it is necessary to reduce the pressure of high-pressure reaction raw materials and transport them to the subsequent reactor, and filter out impurities in the raw materials to ensure the smooth progress of the reaction. ②Laboratory: In the laboratory, the pressure reducing filter valve 3 is often used to reduce pressure and filter the gas or liquid supply system of the experimental equipment to ensure the stability of the experimental environment and the accuracy of the experimental results. For example, in some experiments that require precise control of gas pressure, the pressure reducing filter valve 3 can provide a stable gas source. ③Civil field: In the water supply systems of some high-end residences, hotels and other places, the pressure reducing filter valve 3 can reduce the high pressure of municipal water supply to a suitable level, filter out impurities in the water, and improve the safety and comfort of water use.

[0032] In this embodiment, the throttle valve 4 is a valve that controls the fluid flow rate by changing the throttle cross section or throttle length. The following is a detailed introduction to the throttle valve 4: Working principle: The operation of the throttle valve 4 is based on the principle of fluid mechanics. It controls the flow rate of the fluid by changing the flow area between the valve disc and the valve seat. When the valve disc is opened to a large extent, the fluid flow area is large and the flow rate is large; conversely, when the valve disc is opened to a small extent, the fluid flow area becomes smaller, the resistance to the fluid increases, and the flow rate decreases accordingly. At the same time, during the throttling process, since the fluid channel becomes smaller and the flow rate increases, according to the Bernoulli principle, the pressure of the fluid will decrease accordingly, so the throttle valve 4 can also adjust the pressure of the fluid to a certain extent.

[0033] Structural features: ① Valve body: It is the main structure of the throttle valve 4, which is used to accommodate other components and is connected to the pipeline so that the fluid can flow in the valve body. The material of the valve body is selected according to different usage scenarios and fluid properties. Common ones are cast iron, cast steel, stainless steel, etc. ② Valve disc: It is a key component of the throttle valve 4. It controls the fluid flow by changing the size of the gap between it and the valve seat. The shape and structure of the valve disc are diverse, and the common ones are needle type, ball type, cone type, etc. ③ Valve stem: Connect the valve disc and the handwheel or actuator. By turning the handwheel or driving the actuator, the valve stem moves up and down, thereby driving the valve disc to change the opening degree. ④ Seal: Used to ensure the sealing of the throttle valve 4 and prevent fluid leakage. Common sealing materials include rubber, polytetrafluoroethylene, etc.

[0034] Types: ① Needle-type throttle valve 4: The valve disc is needle-shaped, with a small contact area with the valve seat. The needle-type valve disc is moved up and down by rotating the valve stem to achieve fine adjustment of the flow rate. It is suitable for occasions that require high flow regulation accuracy and small flow, such as laboratory instruments, chemical instruments, etc. ② Ball-type throttle valve 4: The valve disc is a sphere with a circular through hole on the sphere. The flow rate is controlled by rotating the sphere to adjust the degree of alignment between the through hole and the pipeline. It has the characteristics of simple structure and large flow capacity. It is suitable for some occasions that do not require particularly high flow regulation accuracy but require a large flow to pass. ③ Conical throttle valve 4: The valve disc is conical in shape and cooperates with the valve seat to achieve throttling. Its adjustment performance is between the needle-type and ball-type throttle valves 4, and can be selected according to different working conditions.

[0035] Application fields: ①Industrial field: In the chemical, petroleum, electric power and other industries, the throttle valve 4 is used to control the flow and pressure of the fluid to meet the requirements of the production process. For example, in chemical production, the flow of the reaction material is controlled by the throttle valve 4 to ensure that the reaction proceeds at a predetermined rate; in petroleum refining, it is used to adjust the flow and pressure of the oil in the pipeline. ②Refrigeration and air-conditioning system: In the refrigeration system, the throttle valve 4 is one of the important components. It reduces the pressure by throttling, so that the high-temperature and high-pressure refrigerant liquid becomes a low-temperature and low-pressure gas-liquid mixture, providing the evaporator with a suitable refrigerant flow, thereby achieving a refrigeration effect. Common ones include capillary throttle valves 4 and thermal expansion valves. ③Hydraulic system: In the hydraulic system, the throttle valve 4 is used to adjust the flow of hydraulic oil, thereby controlling the movement speed of the actuator (such as a hydraulic cylinder and a hydraulic motor). By adjusting the opening of the throttle valve 4, the working speed of the hydraulic system can be accurately controlled.

[0036] Selection points: ① Flow range: According to the actual flow rate of the fluid to be controlled, select a throttle valve 4 that can meet the maximum flow and minimum flow requirements. Make sure that the rated flow of the throttle valve 4 is greater than the maximum working flow of the system to ensure the normal operation of the system. ② Pressure level: According to the working pressure of the pipeline system, select a throttle valve 4 of the corresponding pressure level. The rated pressure of the throttle valve 4 should not be lower than the maximum working pressure of the system to ensure the safety and reliability of the valve. ③ Fluid properties: Consider the type, temperature, viscosity, corrosiveness and other properties of the fluid. For corrosive fluids, a throttle valve 4 made of corrosion-resistant materials should be selected; for high-temperature fluids, materials and seals that can withstand the corresponding temperature should be selected. ④ Regulation accuracy requirements: If the flow regulation accuracy requirements are high, a needle-type throttle valve 4 or other types with high regulation accuracy should be selected; if the flow regulation accuracy requirements are not high, a ball-type throttle valve 4 with a simple structure and low cost can be selected.

[0037] like Figure 1As shown, the gas path of the positive pressure cabinet 12 is respectively connected with an explosion-proof high-pressure differential pressure switch 5, an explosion-proof low-pressure differential pressure switch 6 and a pressure gauge 7, and these three gauges are arranged on the positive pressure cabinet 12. The explosion-proof high-pressure differential pressure switch 5 is used to set the high-pressure setting value of the positive pressure cabinet 12, the explosion-proof low-pressure differential pressure switch 6 is used to set the low-pressure setting value of the positive pressure cabinet 12, and the pressure gauge 7 is used to display the pressure in the positive pressure cabinet 12. A pressure value range of the positive pressure cabinet 12 is formed by setting the low-pressure setting value and the high-pressure setting value. Within this range, the explosion-proof high-pressure differential pressure switch 5 and the explosion-proof low-pressure differential pressure switch 6 will not be triggered. Only outside this range, the explosion-proof high-pressure differential pressure switch 5 and the explosion-proof low-pressure differential pressure switch 6 will be triggered accordingly.

[0038] In this embodiment, the explosion-proof high-pressure differential pressure switch 5 and the explosion-proof low-pressure differential pressure switch 6 have certain similarities in structure, but there are also some differences. The following are their specific details: 1. Structure ① Explosion-proof high-pressure differential pressure switch 5: It is mainly composed of high-pressure chamber, low-pressure chamber, pressure-sensitive diaphragm, spring, lever, micro switch, etc. The high-pressure chamber and the low-pressure chamber are respectively connected to the two parts that need to monitor the pressure difference. When there is a pressure difference between the high-pressure chamber and the low-pressure chamber, the pressure-sensitive diaphragm will deform, and this deformation is transmitted to the micro switch through the spring and lever, thereby triggering the switch action and outputting an electrical signal.

[0039] ② Explosion-proof low-pressure differential pressure switch 6: It also contains two chambers (high-pressure chamber and low-pressure chamber), sealing diaphragm, differential pressure sensing diaphragm, spring and micro switch and other components. The working principle of low-pressure differential pressure switch is similar to that of high-pressure differential pressure switch, but it is designed to detect lower pressure difference. Its two chambers are respectively connected to the high-pressure side and low-pressure side of the measured system. When the pressure difference on both sides reaches the set value, the differential pressure sensing diaphragm deforms, triggers the micro switch through mechanical structures such as springs, and outputs electrical signals.

[0040] 2. Similarities and differences ①Similarities: Basic structure: It is composed of two cavities (high-pressure chamber and low-pressure chamber), sealing diaphragm, differential pressure diaphragm, spring, micro switch and other basic components.

[0041] Working principle: The pressure difference between the two cavities is used to deform the pressure-sensitive diaphragm, and the deformation is transmitted to the micro switch through the mechanical structure, thereby realizing the action of the switch and the output of the electrical signal.

[0042] Explosion-proof performance: They all have explosion-proof functions and can be used safely in environments with explosion hazards. Their casings are usually made of explosion-proof materials and comply with relevant explosion-proof standards and certifications.

[0043] ② Differences: Pressure detection range: The explosion-proof high-pressure differential pressure switch 5 is used to detect higher pressure differences, and its tolerable pressure range and set action pressure value are relatively high; while the explosion-proof low-pressure differential pressure switch 6 is suitable for detecting lower pressure differences, and its pressure detection range and action pressure value are relatively low.

[0044] Design of diaphragm and spring: Due to the need to withstand different pressures, the diaphragm and spring of the explosion-proof high-pressure differential pressure switch 5 are usually designed to be stronger to adapt to the high-pressure environment; while the diaphragm and spring of the explosion-proof low-pressure differential pressure switch 6 are relatively more sensitive and can respond to smaller pressure changes.

[0045] like Figure 1 As shown, the pressure reducing filter valve 3 is connected to the explosion-proof air supply solenoid valve 9, which is connected to the air inlet end of the air circuit of the positive pressure cabinet 12, so that the explosion-proof air supply solenoid valve 9 and the throttle valve 4 are arranged in parallel, that is, the gas can pass through the explosion-proof air supply solenoid valve 9 and the throttle valve 4 to enter the positive pressure cabinet 12 at the same time. When the pressure in the positive pressure cabinet 12 is lower than the low pressure setting value, the explosion-proof air supply solenoid valve 9 is opened to supply air to the positive pressure cabinet 12, thereby increasing the pressure in the positive pressure cabinet 12.

[0046] At the same time, the air outlet end of the positive pressure cabinet 12 gas circuit is connected to an explosion-proof exhaust solenoid valve 10. When the pressure inside the positive pressure cabinet 12 is higher than the high pressure setting value, the explosion-proof exhaust solenoid valve 10 is opened to exhaust the positive pressure cabinet 12, thereby reducing the pressure inside the positive pressure cabinet 12.

[0047] When the explosion-proof low-pressure differential pressure switch 6 detects that the pressure in the positive pressure cabinet 12 reaches the low-pressure setting value, the explosion-proof air supply solenoid valve 9 will automatically start working, increase the air intake to supply air to the cabinet until the air pressure meets the positive pressure setting value; when the explosion-proof high-pressure differential pressure switch 5 detects that the pressure in the positive pressure cabinet 12 is higher than the high-pressure setting value, the explosion-proof exhaust solenoid valve 10 will automatically start working, increase the exhaust volume to exhaust the cabinet until the air pressure meets the positive pressure setting value. It operates continuously and stably, avoids manual operation by staff, reduces labor intensity, improves efficiency, and ensures stable system operation.

[0048] In this embodiment, Figure 1 As shown, the air outlet end of the air circuit of the positive pressure cabinet 12 is connected to a second valve 13, so that the second valve 13 and the explosion-proof exhaust solenoid valve 10 are arranged in parallel structure, so that the second valve 13 and the explosion-proof exhaust solenoid valve 10 can work side by side at the same time, that is, the gas can be discharged from the positive pressure cabinet 12 through the second valve 13 and the explosion-proof exhaust solenoid valve 10 at the same time.

[0049] like Figure 1 As shown, the second valve 13 and the gas outlet of the explosion-proof exhaust solenoid valve 10 are both provided with a fire barrier 11 to limit the discharge of dangerous substances. The fire barrier 11 can effectively prevent flames or hot particles from entering the dangerous area.

[0050] The fire barrier sheet 11 is mainly used to prevent the flame from spreading in the flammable gas or liquid pipeline, and prevent the occurrence of explosion and fire. The following is a detailed introduction to the fire barrier sheet 11: 1. Working Principle ① Heat transfer effect: Combustion needs to reach a certain temperature, namely the ignition point. When the flame passes through the numerous small channels of the fire barrier sheet 11, it will be divided into several small flames. The fire barrier sheet 11 increases the contact area between the small flames and the channel wall, strengthens the heat transfer, and reduces the flame temperature below the ignition point, thereby preventing the flame from spreading.

[0051] ② Wall effect: Combustion and explosion are the process of free radicals generated by the destruction of molecular bonds due to the stimulation of external energy, and the free radicals react with other molecules. When the combustible gas passes through the narrow channel of the fire barrier 11, the probability of collision between the free radicals and the channel wall increases, and the number of free radicals decreases sharply. When the channel is narrow to a certain extent, the collision between the free radicals and the channel wall dominates, the combustion reaction cannot continue, and the flame is blocked.

[0052] 2. Structure and material ① Structural form: Common ones are metal mesh type and corrugated type. The metal mesh type fire barrier sheet 11 is composed of multiple layers of metal mesh. Domestically, 16-22 mesh metal mesh is usually used, which is 4-12 layers. The corrugated type fire barrier sheet 11 is made of corrugated thin plates and flat plates made of stainless steel, copper-nickel alloy, aluminum or aluminum alloy, etc., alternately wound around the central axis to form a stacked triangular pore fire barrier layer, or a corrugated thin plate material folded in two directions, and the corrugations are separated into many small pores and channels.

[0053] ② Material selection: Generally, materials such as stainless steel, copper-nickel alloy, etc. are used that are corrosion-resistant, high-temperature-resistant, and have a certain strength. These materials can maintain stable performance in harsh working environments, ensuring the reliability and service life of the fire barrier sheet 11.

[0054] 3. Performance characteristics ① Explosion-proof performance: A qualified fire-barrier sheet 11 should be able to prevent the passage of subsonic flames for multiple consecutive times, for example, it should be able to prevent the passage of flames each time after 13 consecutive subsonic flame tests.

[0055] ② Burning resistance: There is no tempering phenomenon in the burning resistance test for a certain period of time, such as no tempering in the burning resistance test for 1 hour, to ensure that the flame can be effectively prevented from spreading under the continuous action of the flame.

[0056] ③ Pressure resistance: The shell and the overall structure where the fire barrier sheet 11 is located should be able to withstand a certain pressure, such as passing a water pressure test of 2.4Mpa without leakage, to ensure that there will be no damage or leakage when the pressure in the pipeline changes.

[0057] In this embodiment, the first valve 2 and the second valve 13 are both electric valves, which can be opened by remote control, thus avoiding manual operation by staff and reducing workload.

[0058] In other embodiments, the first valve 2 and the second valve 13 are both manual valves. When the first valve 2 and the second valve 13 need to be opened, they need to be opened manually.

[0059] The explosion-proof air supply solenoid valve 9, the explosion-proof exhaust solenoid valve 10, the first valve 2, the second valve 13, the explosion-proof high-pressure differential pressure switch 5 and the explosion-proof low-pressure differential pressure switch 6 are all electrically connected to a controller. The controller can control each component, reducing the labor of manual operation and improving efficiency.

[0060] The working process of the present invention is as follows: Connect the air source interface 1, open the first valve 2, adjust the pressure reducing filter valve 3 and the throttle valve 4 to provide positive pressure for the positive pressure cabinet 12; set the low pressure and high pressure setting values ​​so that the positive pressure cabinet 12 maintains positive pressure to the outside and meets the explosion-proof standard requirements. When the explosion-proof low-pressure differential pressure switch 6 detects that the pressure in the positive pressure cabinet 12 reaches the low-pressure setting value, the explosion-proof air supply solenoid valve 9 works to increase the air intake to supply air to the cabinet until the air pressure meets the positive pressure setting value. When the explosion-proof high-pressure differential pressure switch 5 detects that the pressure in the positive pressure cabinet 12 is higher than the high pressure setting value, the explosion-proof exhaust solenoid valve 10 works to increase the exhaust volume to exhaust the cabinet until the air pressure meets the positive pressure setting value, and it runs continuously and stably.

[0061] Embodiment of the pressure control method The intelligent explosion-proof positive pressure control method includes the following steps: connecting the air source interface 1, opening the first valve 2, adjusting the pressure reducing filter valve 3 and the throttle valve 4, and providing positive pressure for the positive pressure cabinet 12; setting the low pressure and high pressure setting values, so that the positive pressure cabinet 12 maintains positive pressure to the outside and meets the explosion-proof standard requirements. When the explosion-proof low-pressure differential pressure switch 6 detects that the pressure in the positive pressure cabinet 12 reaches the low pressure setting value, the explosion-proof air supply solenoid valve 9 works, and increases the air intake to supply air to the cabinet until the air pressure meets the positive pressure setting value. When the explosion-proof high-pressure differential pressure switch 5 detects that the pressure in the positive pressure cabinet 12 is higher than the high pressure setting value, the explosion-proof exhaust solenoid valve 10 works, and increases the exhaust volume to exhaust the cabinet until the air pressure meets the positive pressure setting value, and the operation is continuous and stable. This avoids manual operation and improves efficiency.

[0062] When the positive pressure of the positive pressure cabinet 12 is no longer controlled, the second valve 13 can be opened to release the pressure in the positive pressure cabinet 12.

Claims

1. Intelligent explosion-proof positive pressure control system, including positive pressure cabinet, characterized in that: The air inlet end of the positive pressure cabinet air circuit is connected in sequence with a throttle valve, a pressure reducing filter valve, a first valve and an air source interface; The gas path of the positive pressure cabinet is respectively connected with an explosion-proof high-pressure differential pressure switch, an explosion-proof low-pressure differential pressure switch and a pressure gauge, wherein the explosion-proof high-pressure differential pressure switch is used to set the high-pressure setting value of the positive pressure cabinet, the explosion-proof low-pressure differential pressure switch is used to set the low-pressure setting value of the positive pressure cabinet, and the pressure gauge is used to display the pressure in the positive pressure cabinet; The pressure reducing filter valve is connected to an explosion-proof air supply solenoid valve, which is connected to the air inlet end of the positive pressure cabinet gas circuit, so that the explosion-proof air supply solenoid valve and the throttle valve are arranged in parallel. When the pressure in the positive pressure cabinet is lower than the low pressure setting value, the explosion-proof air supply solenoid valve is opened to supply air to the positive pressure cabinet; The gas outlet end of the positive pressure cabinet gas circuit is connected with an explosion-proof exhaust solenoid valve. When the pressure in the positive pressure cabinet is higher than the high pressure setting value, the explosion-proof exhaust solenoid valve is opened to exhaust the positive pressure cabinet.

2. The intelligent explosion-proof positive pressure control system according to claim 1 is characterized in that: The gas outlet end of the positive pressure cabinet gas circuit is connected with a second valve, so that the second valve and the explosion-proof exhaust solenoid valve are arranged in parallel structure.

3. The intelligent explosion-proof positive pressure control system according to claim 2 is characterized in that: The gas outlet ends of the second valve and the explosion-proof exhaust solenoid valve are provided with fire-blocking plates to limit the discharge of hazardous substances.

4. The intelligent explosion-proof positive pressure control system according to claim 3 is characterized in that: The gas source interface is connected to a gas supply device, and the gas supply device is used to provide inert gas or air to the gas source interface.

5. The intelligent explosion-proof positive pressure control system according to claim 4 is characterized in that: An air circuit is arranged in the positive pressure cabinet, and the air circuit has an air inlet end and an air outlet end.

6. The intelligent explosion-proof positive pressure control system according to any one of claims 2 to 5, characterized in that: The first valve and the second valve are both manual valves.

7. The intelligent explosion-proof positive pressure control system according to any one of claims 2 to 5, characterized in that: The first valve and the second valve are both electric valves.

8. The intelligent explosion-proof positive pressure control system according to claim 7 is characterized in that: The explosion-proof air supply solenoid valve, the explosion-proof exhaust solenoid valve, the first valve, the second valve, the explosion-proof high-pressure differential pressure switch and the explosion-proof low-pressure differential pressure switch are all electrically connected to a controller.

9. Intelligent explosion-proof positive pressure control method, characterized in that: The method comprises the following steps: connecting the air source interface, opening the first valve, adjusting the pressure reducing filter valve and the throttle valve to provide positive pressure for the positive pressure cabinet; setting the low pressure and high pressure setting values ​​so that the positive pressure cabinet maintains positive pressure to the outside and meets the explosion-proof standard requirements; When the explosion-proof low-pressure differential pressure switch detects that the pressure in the positive pressure cabinet reaches the low-pressure setting value, the explosion-proof air supply solenoid valve works to increase the air intake to supply air to the cabinet until the air pressure meets the positive pressure setting value; When the explosion-proof high-pressure differential pressure switch detects that the pressure in the positive pressure cabinet is higher than the high-pressure setting value, the explosion-proof exhaust solenoid valve will work, increase the exhaust volume to exhaust the cabinet until the air pressure meets the positive pressure setting value, and operate continuously and stably.

10. The intelligent explosion-proof positive pressure control method according to claim 9, characterized in that: When the positive pressure of the positive pressure cabinet is no longer controlled, the second valve can be opened to release the pressure in the positive pressure cabinet.

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