Preparation device and method of air-nitrogen double-medium compressed air source

Abstract

The invention discloses a preparation device and method of an air-nitrogen double-medium compressed air source, the preparation device comprises a pipeline system and a preparation system of the compressed air source, the pipeline system comprises an air inlet pipeline, a connecting pipeline, a nitrogen-rich gas outlet pipeline, an oxygen-rich gas outlet pipeline and a compressed air outlet pipeline; the preparation system of the compressed air source comprises an air compressor, a cooler, a gas-liquid separator, a multi-stage filter, a heat exchanger and a separation membrane group; aiming at the problem that a compressed nitrogen drilling machine brings safety threats to operators when the drilling machine is in a drilling state, a solution that an air-nitrogen double-medium compressed air source serves as drilling power is provided, and the two-position three-way valve is adopted; the drilling machine matched with the double-medium compressed air source outputs compressed air in the tapping state, after a drill rod and a drill bit enter a coal seam, compressed nitrogen is output, and double-mode output is formed so as to adapt to the air supply requirements in different environments, and the applicability of the equipment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mine underground gas source devices, and in particular to a device and method for preparing an air-nitrogen dual-medium compressed gas source. Background Art

[0002] Underground coal mine gas extraction is the process of extracting gas from coal seams and goafs to the surface using gas extraction equipment during the mining process. Gas extraction not only helps reduce gas outbursts during mining and prevent gas explosions, but also allows gas to be developed and utilized as a coal-associated resource. Drilling rigs for gas extraction are essential equipment for underground coal mine operations. Drilling rigs can be powered by hydraulic power or compressed air. Hydraulic power not only provides power but also removes slag and cools the drill bit, making it widely used. However, in soft coal seams, hydraulic drilling can easily cause hole collapse, hindering drilling. Compressed air drilling power is the preferred choice. However, a mixture of gas and air within a certain range can explode when exposed to a fire source. Compressed nitrogen, as an inert gas, effectively prevents the risk of spontaneous combustion underground.

[0003] Compressed nitrogen drilling rigs compress nitrogen from low pressure to high pressure. As the nitrogen flows through the drill bit, it cools the drill and carries drill cuttings before being discharged through the wellhead and sand removal pipeline, achieving the desired drilling result. Furthermore, it protects low-pressure oil and gas reservoirs and aquifers, preventing reservoir damage and increasing production efficiency. However, when a compressed nitrogen drilling rig is in the drilling phase, the drill rod and drill bit have not yet entered the coal seam, leaving the rig exposed. Nitrogen levels in the drilling plant surge, while oxygen levels plummet, posing a significant risk to operators. The Coal Mine Safety Regulations stipulate that the oxygen concentration in underground work areas must not be less than 20%. Therefore, different work stages require different levels of nitrogen and air. Existing nitrogen generation equipment is unable to adapt to the requirements of air drilling processes and must switch between nitrogen and air output modes based on actual needs.

[0004] Furthermore, due to the conditions of underground coal mine construction, nitrogen generators are located in the main tunnels of the mine. Their function is to provide a fire-fighting and slag-removing gas source for drilling rigs in the drilling field. The nitrogen generators are typically hundreds of meters away from the drilling rigs. Currently, nitrogen generator control typically involves a staff member stationed nearby. When gas users need it, they notify the personnel at the nitrogen generator via phone calls. This prevents proper synchronization between gas demand and supply, resulting in poor safety and reliability. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a device and method for preparing an air-nitrogen dual-medium compressed gas source, so as to solve the problems that the nitrogen production equipment in the existing technology cannot adapt to the requirements of the air drilling process, cannot switch between the output nitrogen or air modes according to actual needs, and cannot achieve good synchronization between gas demand and supply, resulting in poor safety and reliability.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution to achieve them: a preparation device for an air-nitrogen dual-medium compressed gas source, including a pipeline system and a compressed gas source preparation system installed on the pipeline system.

[0007] The pipeline system includes an air inlet pipeline, a connecting pipeline, a nitrogen-rich gas outlet pipeline, an oxygen-rich gas outlet pipeline and a compressed air outlet pipeline.

[0008] The compressed gas source preparation system includes an air compressor, a cooler, a gas-liquid separator, a multi-stage filter, a heat exchanger and a separation membrane group.

[0009] A two-position three-way valve is provided between the heat exchanger and the separation membrane group. The two-position three-way valve is a solenoid valve, and a control end of the valve is connected to a control signal line.

[0010] The air inlet pipeline is connected to the inlet end of the air compressor, and the outlet end of the air compressor is connected to the connecting pipeline.

[0011] The cooler, gas-liquid separator, multi-stage filter, heat exchanger, separation membrane group and two-position three-way valve are all installed on the connecting pipeline.

[0012] The inlet of the two-position three-way valve is connected to the outlet of the heat exchanger, one of the two outlets of the two-position three-way valve is connected to the compressed air outlet pipeline, and the other is connected to the inlet of the separation membrane group.

[0013] The separation membrane group further comprises two outlet ends, one of which is connected to a nitrogen-rich gas outlet pipeline, and the other is connected to an oxygen-rich gas outlet pipeline.

[0014] The present invention also has the following technical features:

[0015] The multi-stage filter comprises a precision filter, an ultra-precision filter, an activated carbon filter and a particle filter which are connected in sequence.

[0016] The precision filter, ultra-precision filter, activated carbon filter and particle filter are all arranged on the connecting pipeline.

[0017] The precision filter is communicated with the gas-liquid separator, and the particle filter is communicated with the heat exchanger.

[0018] The compressed gas source preparation system also includes an oxygen analyzer, a meter and a purity control valve.

[0019] The oxygen analyzer, meter and purity control valve are installed on the nitrogen-rich gas outlet pipeline.

[0020] The cooler is a partition-type heat exchanger, with cooling fluid flowing on one side and compressed air flowing on the other side.

[0021] The heat exchanger is also a partition-type heat exchanger, with filtered compressed air passing through one side and hot fluid passing through the other side.

[0022] The cold fluid in the cooler is connected to the hot fluid in the heat exchanger through pipelines and pumps. The cold and hot fluid pipelines are also provided with bypasses to introduce cold and hot fluids supplied from the outside.

[0023] The air inlet pipeline, connecting pipeline, nitrogen-rich gas outlet pipeline, oxygen-rich gas outlet pipeline and compressed air outlet pipeline are all equipped with pressure gauges, temperature sensors and flow meters.

[0024] It also includes a closed shell, and the compressed gas source preparation system on the pipeline system is placed in the closed shell.

[0025] The bottom of the closed shell is provided with movable rollers, and the outside of the closed shell is provided with doors and windows for convenient passage of pipelines and lines.

[0026] The present invention also provides a method for preparing an air-nitrogen dual-medium compressed gas source, which is completed using the above-mentioned air-nitrogen dual-medium compressed gas source preparation device.

[0027] Step 1: Equipment preparation: At the beginning, complete the initialization of the two-position three-way valve, set parameters, calibrate the valve, etc.

[0028] Step 2: Signal reception: When the PLC control system receives the signal sent by the gas end, the signal will be converted into an electrical signal.

[0029] Step 3: Signal processing: The PLC control system processes the received electrical signal, including amplification, filtering, and shaping of the signal to adapt to the next step.

[0030] Step 4: Solenoid valve control: The processed electrical signal is sent to the solenoid valve, which converts the electrical signal into a pneumatic signal to control the opening and closing of the two-position three-way valve.

[0031] Step 5: Execute the operation: The opening and closing of the two-position three-way valve will be controlled by the pneumatic signal. When the pneumatic signal reaches a certain intensity, the two-position three-way valve will be opened or closed.

[0032] Step 6: Process execution: When the two-position three-way valve is opened or closed, the free switching process of using clean compressed air and producing nitrogen by the membrane module is realized.

[0033] Compared with the prior art, the present invention has the following technical effects:

[0034] (I) The present invention provides a preparation device for an air-nitrogen dual-medium compressed gas source. Aiming at the safety threat posed to operators by a compressed nitrogen drilling rig when the drilling rig is in the drilling state, the present invention proposes a solution using an air-nitrogen dual-medium compressed gas source as a drilling power source. A two-position three-way valve is used to match the drilling rig with the dual-medium compressed gas source to output compressed air in the drilling state. When the drill rod and drill bit enter the coal seam, the valve switches to outputting compressed nitrogen, forming a dual-mode output to adapt to the gas supply needs in different environments, thereby improving the applicability of the equipment.

[0035] (II) The present invention provides a device for preparing an air-nitrogen dual-medium compressed gas source. By modifying a traditional nitrogen generator, a dual-mode output is adopted to realize that the compressed air discharged from the air compressor of the nitrogen generator can be supplied to the nitrogen-making membrane to produce nitrogen for user use after treatment, and can also supply clean compressed air through a three-way valve switching. The dual-mode automatic switching is realized by combining a remote and proximal combined control method.

[0036] (III) The method for preparing an air-nitrogen dual-medium compressed gas source provided by the present invention is simple to operate and easy to maintain, reduces the cost of use, and has high economic and social benefits.

[0037] (IV) The method for preparing an air-nitrogen dual-medium compressed gas source provided by the present invention effectively reduces the occupational disease risk of operators and protects the health of workers. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0039] The meaning of each reference numeral in the accompanying drawings:

[0040] 1- Piping system, 2- Compressed gas source preparation system.

[0041] 1-1-air inlet pipe, 1-2-connecting pipe, 1-3-nitrogen-rich gas outlet pipe, 1-4-oxygen-rich gas outlet pipe, 1-5-compressed air outlet pipe.

[0042] 2-1-Air compressor, 2-2-Cooler, 2-3-Gas-liquid separator, 2-4-Multi-stage filter, 2-5-Heat exchanger, 2-6-Separation membrane group, 2-7-Two-position three-way valve, 2-8-Oxygen analyzer, 2-9-Metering instrument, 2-10-Purity control valve.

[0043] 2-4-1 precision filter, 2-4-2 ultra-precision filter, 2-4-3 activated carbon filter, 2-4-4 particle filter.

[0044] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0045] Unless otherwise specified, all components in the present invention are components known in the prior art.

[0046] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0047] Example 1:

[0048] This embodiment provides a preparation device for an air-nitrogen dual-medium compressed gas source, such as Figure 1 As shown, it includes a pipeline system 1 and a compressed gas source preparation system 2 installed on the pipeline system 1.

[0049] The pipeline system 1 includes an air inlet pipeline 1-1, a connecting pipeline 1-2, a nitrogen-rich gas outlet pipeline 1-3, an oxygen-rich gas outlet pipeline 1-4 and a compressed air outlet pipeline 1-5.

[0050] The compressed gas source preparation system 2 includes an air compressor 2-1, a cooler 2-2, a gas-liquid separator 2-3, a multi-stage filter 2-4, a heat exchanger 2-5 and a separation membrane group 2-6.

[0051] A two-position three-way valve 2-7 is provided between the heat exchanger 2-5 and the separation membrane group 2-6. The two-position three-way valve 2-7 is a solenoid valve, and a control end of the valve is connected to a control signal line.

[0052] The air inlet pipe 1-1 is connected to the inlet end of the air compressor 2-1, and the outlet end of the air compressor 2-1 is connected to the connecting pipe 1-2.

[0053] The cooler 2-2, gas-liquid separator 2-3, multi-stage filter 2-4, heat exchanger 2-5, separation membrane group 2-6, and two-position three-way valve 2-7 are all installed on the connecting pipeline 1-2.

[0054] The inlet of the two-position three-way valve 2-7 is connected to the outlet of the heat exchanger 2-5, one of the two outlets of the two-position three-way valve 2-7 is connected to the compressed air outlet pipeline 1-5, and the other is connected to the inlet of the separation membrane group 2-6.

[0055] The separation membrane group 2-6 includes two outlet ends, one of which is connected to the nitrogen-rich gas outlet pipeline 1-3, and the other is connected to the oxygen-rich gas outlet pipeline 1-4.

[0056] The air compressor 2-1 is a screw compressor.

[0057] After being compressed by the screw compressor and cooled by the cooler 2-2, the air enters the gas-liquid separator 2-3 and the precision filter 2-4-1 to remove the liquid and oil mist in the compressed air. The air is then filtered by the first-level ultra-precision filter 2-4-2 and the first-level activated carbon filter 2-4-3 to remove the micro oil mist and VOC, which can reduce the oil content in the compressed air to below 0.01 mg / m3 and can filter out all solid particles with a diameter greater than 0.01 m. The air then enters the heat exchanger 2-5 for heat exchange, so that the separation membrane group 2-6 works under the optimal temperature conditions.

[0058] After the purification process, the compressed air at a constant temperature and pressure enters the separation membrane group 2-6 for oxygen / nitrogen separation. The membrane separation produces high-pressure nitrogen slightly lower than the inlet pressure. The two-position three-way valve 2-7 switches between outputting nitrogen through the nitrogen-enriched gas outlet line 1-3 and outputting compressed air through the compressed air outlet line 1-5.

[0059] Compared with the single purpose of traditional nitrogen generators, the air-nitrogen dual-medium compressed gas source preparation device disclosed in the present invention can realize the supply of two compressed gas sources by one machine, meeting the changing needs of mine drilling rigs or other gas users for the gas medium at different stages, and controlling the two-position three-way valve by sending signals after monitoring real-time data for judgment, which is more accurate and quicker than manually starting and stopping the gas.

[0060] As a preferred embodiment of this invention:

[0061] The multi-stage filter 2-4 includes a precision filter 2-4-1, an ultra-precision filter 2-4-2, an activated carbon filter 2-4-3 and a particle filter 2-4-4 which are connected in sequence.

[0062] The precision filter 2-4-1, ultra-precision filter 2-4-2, activated carbon filter 2-4-3 and particle filter 2-4-4 are all arranged on the connecting pipe 1-2.

[0063] The precision filter 2-4-1 is connected to the gas-liquid separator 2-3, and the particle filter 2-4-4 is connected to the heat exchanger 2-5.

[0064] The filtration accuracy of precision filters is usually 1 to 50 microns (μm), which can intercept particles, suspended matter, some bacteria, etc. Its application scenarios include industrial pretreatment, drinking water purification, food and beverage production, etc. Common types include bag filters, melt-blown filter elements (PP cotton), stainless steel filters, etc.

[0065] The filtration accuracy of ultra-precision filters is as high as 0.1 to 0.01 microns (100 to 10 nanometers), and they can remove viruses, colloids, large molecular organic matter, etc. Their application scenarios include semiconductor ultrapure water, biopharmaceuticals, high-end laboratories, nanomaterial preparation, etc. Common types include hollow fiber membranes, ceramic membranes, reverse osmosis (RO) membranes, etc.

[0066] Activated carbon filter is a purification device with activated carbon as the core filter material. It absorbs pollutants in water or air, including organic matter, odor, heavy metals and harmful gases, through its developed pore structure and huge specific surface area.

[0067] A particle filter is a filtration device that uses solid granular materials (such as activated carbon or quartz sand) as its core filter material. It removes impurities from liquids or gases through physical interception and adsorption. The core filter material (such as activated carbon particles) has a porous structure and high specific surface area, effectively intercepting suspended solids, organic matter, odors, and some soluble pollutants.

[0068] As a preferred embodiment of this invention:

[0069] The compressed gas source preparation system 2 also includes an oxygen analyzer 2-8, a meter 2-9 and a purity control valve 2-10.

[0070] The oxygen analyzer 2-8, meter 2-9 and purity control valve 2-10 are installed on the nitrogen-rich gas outlet pipeline 1-3.

[0071] As a preferred embodiment of this invention:

[0072] The cooler 2-2 is a partition-type heat exchanger, with cold fluid flowing on one side and compressed air flowing on the other side.

[0073] The heat exchangers 2-5 are also partition-type heat exchangers, with filtered compressed air passing through one side and hot fluid passing through the other side.

[0074] The cold fluid in the cooler 2-2 is connected to the hot fluid in the heat exchanger 2-5 through a pipeline and a pump. The cold and hot fluid pipelines are also provided with a bypass, which introduces cold and hot fluids supplied from the outside. The compressed air coming out of the heat exchanger is controlled at 45-55℃.

[0075] As a preferred embodiment of this invention:

[0076] The air inlet pipeline 1-1, the connecting pipeline 1-2, the nitrogen-rich gas outlet pipeline 1-3, the oxygen-rich gas outlet pipeline 1-4 and the compressed air outlet pipeline 1-5 are all equipped with pressure gauges, temperature sensors and flow meters.

[0077] As a preferred embodiment of this invention:

[0078] It also includes a closed shell, in which the compressed gas source preparation system 2 on the pipeline system 1 is placed.

[0079] The bottom of the closed shell is provided with movable rollers, and the outside of the closed shell is provided with doors and windows for convenient passage of pipelines and lines.

[0080] Example 2:

[0081] A method for preparing an air-nitrogen dual-medium compressed gas source is characterized in that it is completed using the air-nitrogen dual-medium compressed gas source preparation device as described in Example 1.

[0082] Step 1: Equipment preparation: At the beginning, complete the initialization settings of the two-position three-way valve 2-7, set parameters, calibrate the valve, etc.

[0083] Step 2: Signal reception: When the PLC control system receives the signal sent by the gas end, the signal will be converted into an electrical signal.

[0084] Step 3: Signal processing: The PLC control system processes the received electrical signal, including amplification, filtering, and shaping of the signal to adapt to the next step.

[0085] Step 4: Solenoid valve control: The processed electrical signal is sent to the solenoid valve, which converts the electrical signal into a pneumatic signal to control the opening and closing of the two-position three-way valve 2-7.

[0086] Step 5: Execute the operation: The opening and closing of the two-position three-way valve 2-7 will be controlled by the pneumatic signal. When the pneumatic signal reaches a certain intensity, the two-position three-way valve 2-7 will be opened or closed.

[0087] Step 6: Process execution: When the two-position three-way valve 2-7 is opened or closed, the free switching process of using clean compressed air and producing nitrogen by the membrane module is realized.

[0088] This method uses two SIMATIC S7-1200 series controllers to realize the joint control of the gas production end and the gas consumption end, which are respectively arranged on the proximal dual-medium compressed gas generator car body and the distal gas consumption end car body.

[0089] The controller CPU combines a microprocessor, integrated power supply, input and output circuits, built-in PROFINET, high-speed motion control I / O, and onboard analog inputs into a compact housing to form an overall controller.

[0090] The SIMATIC S7-1200 series controller has 14 digital inputs, 2 analog inputs, and 10 digital outputs. The controller also supports expansion functions and can be equipped with optional SM1231 and SM1232 expansion boards, which can provide 8 analog inputs and 4 analog outputs, respectively, which are sufficient for 2-6 separation membrane groups.

[0091] The PLC input includes: 3 pressure transmitters, 3 temperature sensors, 1 flow meter, and 1 oxygen concentration analyzer. The input is intended to adopt analog input. The pressure transmitter and temperature sensor respectively detect the pressure and temperature of raw air, membrane group intake air, and membrane group exhaust air. The flow meter can monitor the gas flow in the pipeline in real time. The oxygen concentration analyzer can detect the oxygen concentration in the finished gas to determine whether the nitrogen concentration of the finished gas reaches the set threshold.

[0092] The output of the PLC includes: 1 two-position three-way valve, 1 exhaust valve, 1 vent valve, and 1 sound and light alarm. The output is intended to adopt digital limit output. The two-position three-way valve is used to switch the air / nitrogen working mode, the exhaust valve is used to discharge the finished gas, and the vent valve is used to discharge unqualified finished gas. When the gas pressure or temperature in the system exceeds the safe range, an alarm can be given through the sound and light alarm.

[0093] The control method is implemented by connecting the PROFINET port of the PLC device to an external display screen to realize visualization of various state parameters during system operation.

[0094] The PLC is also equipped with CM CANopen and CM1241 communication modules, providing CAN communication and RS422 / 485 communication, facilitating the access of sensors with various interface types and data interaction.

[0095] The remote controller can be equipped with a remote controller to send operation instructions to the controller wirelessly.

[0096] The preparation and control method of the air-nitrogen dual-medium compressed gas source has the following workflow:

[0097] Before drilling, drilling site construction personnel manually set the air compressor exhaust pressure, select the output pressure, and set the separation membrane group 2-6 working mode (air supply / nitrogen supply) and the product gas concentration index when nitrogen supply is used through the remote control according to the drilling process requirements.

[0098] After completing the settings, press the start button, and the start command and setting parameters are transmitted to the nitrogen generator proximal controller via the bus or ring network. The system is started through the main electrical control box, and the air compressor onboard temperature and pressure transmitter monitors the air compressor inlet temperature and pressure.

[0099] If the intake air temperature and pressure exceed the standard, the main electrical control box will automatically stop and sound a visual alarm. If the intake air temperature and pressure are normal, the air compressor 2-1 will start working and filter, deoil and purify the air source in turn. The system monitors the gas temperature and pressure in the pipeline in real time to ensure that it always meets the set requirements.

[0100] Before the gas pre-treated by the air compressor 2-1 enters the separation membrane group 2-6, its inlet pressure, flow rate and operating temperature are measured. If they exceed the set range, the system will issue an alarm. If all indicators are normal, the system will start operation.

[0101] At this time, the separation membrane group 2-6 performs actions according to the working mode set by the operator. If it is an air supply mode, the valve is opened directly to supply gas. If it is a nitrogen supply mode, the gas source is passed into the separation membrane group 2-6 for nitrogen and oxygen separation. After the separation is completed, the nitrogen concentration in the finished gas is detected. If the concentration reaches the manually set threshold, the valve is opened to supply gas, otherwise the bypass is emptied to ensure that the product gas meets the concentration standard. The gas pressure, temperature and other information during the system operation are sent to the remote controller display screen via the bus or ring network for visualization, providing operation information for drilling construction personnel.

[0102] Compared with traditional nitrogen generators that require personnel to perform remote operations through signal communication, the air-nitrogen dual-medium compressed gas source preparation device and control method disclosed in the present invention can achieve multiple controls at the remote and near ends, which is more timely than manual control and improves the flexibility and safety of device operation.

[0103] This embodiment combines "dual-medium compressed gas source generator near-end control" with "drilling rig-end remote control." Drilling personnel at the drilling site can start and stop the nitrogen generator and set its operating mode based on the rig's operating status and drilling process. They also have real-time access to information such as the nitrogen generator's internal gas pressure and temperature. In the event of an unexpected situation, a one-touch emergency stop is supported. The near-end safety officer of the dual-medium compressed gas source generator can also perform safe operations based on the generator's operating status. "Near-end control" and "remote control" are implemented using two controllers, which communicate via a bus or mine ring network.

[0104] To further optimize the system's functionality, based on Examples 1 and 2, the oxygen-enriched gas outlet line 16 is connected to a compressed oxygen cylinder. When oxygen is urgently needed at the gas-consuming end, pure oxygen can be supplied from the oxygen cylinder, achieving alternating production of compressed air and compressed nitrogen while also producing high-quality, high-pressure, enriched oxygen. A small buffer tank is connected behind each of the nitrogen-enriched gas outlet line 15 and the compressed air outlet line 17. This allows for a smooth transition in line pressure when the two-position, three-way valve 13 is switched. In the event of an emergency power outage, the compressed gas in the buffer tank can be manually operated to provide a gas source.

[0105] The above technical solutions are only preferred specific implementation methods of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be thought of by any technician familiar with the field within the technical scope disclosed by the present invention without creative work are all covered by the protection scope of the present invention.

Claims

1. A device for preparing an air-nitrogen dual-medium compressed gas source, comprising a pipeline system (1) and a compressed gas source preparation system (2) installed on the pipeline system (1), characterized in that: The pipeline system (1) comprises an air inlet pipeline (1-1), a connecting pipeline (1-2), a nitrogen-rich gas outlet pipeline (1-3), an oxygen-rich gas outlet pipeline (1-4) and a compressed air outlet pipeline (1-5); The compressed gas source preparation system (2) includes an air compressor (2-1), a cooler (2-2), a gas-liquid separator (2-3), a multi-stage filter (2-4), a heat exchanger (2-5) and a separation membrane group (2-6); A two-position three-way valve (2-7) is provided between the heat exchanger (2-5) and the separation membrane group (2-6). The two-position three-way valve (2-7) is a solenoid valve, and a control end of the valve is connected to a control signal line. The air inlet pipeline (1-1) is connected to the inlet end of the air compressor (2-1), and the outlet end of the air compressor (2-1) is connected to the connecting pipeline (1-2); The cooler (2-2), gas-liquid separator (2-3), multi-stage filter (2-4), heat exchanger (2-5), separation membrane group (2-6), and two-position three-way valve (2-7) are all installed on the connecting pipeline (1-2); The inlet end of the two-position three-way valve (2-7) is connected to the outlet end of the heat exchanger (2-5), one of the two outlet ends of the two-position three-way valve (2-7) is connected to the compressed air outlet pipeline (1-5), and the other is connected to the inlet end of the separation membrane group (2-6); The separation membrane group (2-6) further comprises two outlet ends, one of which is connected to the nitrogen-rich gas outlet pipeline (1-3), and the other is connected to the oxygen-rich gas outlet pipeline (1-4).

2. The air-nitrogen dual-medium compressed gas source preparation device according to claim 1, characterized in that: The multi-stage filter (2-4) comprises a precision filter (2-4-1), an ultra-precision filter (2-4-2), an activated carbon filter (2-4-3) and a particle filter (2-4-4) which are sequentially connected. The precision filter (2-4-1), ultra-precision filter (2-4-2), activated carbon filter (2-4-3) and particle filter (2-4-4) are all arranged on the connecting pipeline (1-2); The precision filter (2-4-1) is connected to the gas-liquid separator (2-3), and the particle filter (2-4-4) is connected to the heat exchanger (2-5).

3. The air-nitrogen dual-medium compressed gas source preparation device according to claim 1, characterized in that: The compressed gas source preparation system (2) further comprises an oxygen analyzer (2-8), a meter (2-9) and a purity control valve (2-10); The oxygen analyzer (2-8), meter (2-9) and purity control valve (2-10) are installed on the nitrogen-rich gas outlet pipeline (1-3).

4. The air-nitrogen dual-medium compressed gas source preparation device according to claim 2, characterized in that: The cooler (2-2) is a partition-type heat exchanger, with cold fluid flowing on one side and compressed air flowing on the other side; The heat exchanger (2-5) is also a partition-type heat exchanger, with filtered compressed air passing through one side and hot fluid passing through the other side; The cold fluid in the cooler (2-2) is connected to the hot fluid in the heat exchanger (2-5) through a pipeline and a pump. The cold and hot fluid pipelines are also provided with a bypass, which introduces cold and hot fluids supplied from the outside.

5. The device for preparing an air-nitrogen dual-medium compressed gas source according to claim 2, characterized in that: The air inlet pipeline (1-1), the connecting pipeline (1-2), the nitrogen-rich gas outlet pipeline (1-3), the oxygen-rich gas outlet pipeline (1-4) and the compressed air outlet pipeline (1-5) are all equipped with a pressure gauge, a temperature sensor and a flow meter.

6. The air-nitrogen dual-medium compressed gas source preparation device according to claim 4, characterized in that: It also includes a closed shell, in which the compressed gas source preparation system (2) on the pipeline system (1) is placed; The bottom of the closed shell is provided with movable rollers, and the outside of the closed shell is provided with doors and windows for convenient passage of pipelines and lines.

7. A method for preparing an air-nitrogen dual-medium compressed gas source, characterized in that: The method is completed by using the air-nitrogen dual-medium compressed gas source preparation device as described in any one of claims 1 to 6; Step 1: Equipment preparation: At the beginning, complete the initialization setting of the two-position three-way valve (2-7); Step 2: Signal reception: When the PLC control system receives the signal sent by the gas end, the signal will be converted into an electrical signal; Step 3: Signal processing: The PLC control system processes the received electrical signal, including amplification, filtering, and shaping of the signal to adapt to the next step; Step 4: Solenoid valve control: The processed electrical signal is sent to the solenoid valve, which converts the electrical signal into a pneumatic signal to control the opening and closing of the two-position three-way valve (2-7); Step 5: Execute the operation: The opening and closing of the two-position three-way valve (2-7) will be controlled by the pneumatic signal. When the pneumatic signal reaches a certain intensity, the two-position three-way valve (2-7) will be opened or closed; Step 6: Process execution: When the two-position three-way valve (2-7) is opened or closed, the free switching process of using clean compressed air and producing nitrogen by the membrane module is realized.

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