Mine zero-energy self-cooling cold nitrogen generating device and method

Abstract

The present application relates to the field of prevention and treatment of coal mine goaf spontaneous combustion disaster, and specifically discloses a mine zero-energy-consumption self-cooling cold nitrogen generating device and method. The device comprises a vortex tube connected with a normal-temperature nitrogen supply source, a cold end pipe for discharging low-temperature nitrogen gas and a hot end pipe for discharging high-temperature nitrogen gas arranged on the vortex tube; a bubble atomizing pipe receives high-temperature nitrogen gas discharged by the hot end pipe and normal-temperature cooling water provided by a normal-temperature cooling water source at one end, and is connected with a gas-water separator at the other end, and outputs nitrogen gas-fine water mist two-phase flow into the gas-water separator; the gas-water separator discharges high-temperature waste water into a drainage ditch and discharges dry near-normal-temperature nitrogen gas into a low-temperature nitrogen gas-near-normal-temperature nitrogen gas mixing chamber; the low-temperature nitrogen gas-near-normal-temperature nitrogen gas mixing chamber receives low-temperature nitrogen gas discharged by the cold end pipe and near-normal-temperature nitrogen gas discharged by the gas-water separator, and the discharged cold nitrogen is injected into a goaf through an outlet joint. The temperature, pressure and flow parameters of the cold nitrogen discharged by the present application are continuously adjustable within a certain range, and can be monitored in real time.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of prevention and treatment of coal mine goaf spontaneous combustion, and particularly discloses a mine zero-energy-consumption self-cooling cold nitrogen generating device and method. BACKGROUND

[0002] Mine fire is one of the five major disasters in coal mines, causing a large number of casualties and property losses. Most of the mine fires are caused by goaf spontaneous combustion. Goaf spontaneous combustion can consume a large amount of coal resources, burn mechanical equipment, cause gas and coal dust explosion, produce a large amount of high-temperature flame and toxic and harmful gases, and seriously threaten the safety production of coal mines. At present, common goaf spontaneous combustion prevention and treatment measures include nitrogen injection fire prevention and extinguishing, yellow mud grouting fire prevention and extinguishing, fire prevention by using resistance agent, gel fire prevention and extinguishing, and three-phase foam fire prevention and extinguishing. Nitrogen injection fire prevention and extinguishing is widely used due to its simple process, convenient operation, and no pollution to the fire prevention and extinguishing area. However, in the daily nitrogen injection fire prevention process, the normal-temperature nitrogen prepared by the nitrogen generator is directly injected into the goaf, and the cooling effect is poor. A large number of studies have shown that the environmental temperature plays a decisive role in the coal-oxygen reaction in the goaf, and reducing the temperature of the nitrogen injected into the goaf can effectively reduce the risk of goaf spontaneous combustion. At present, the nitrogen is cooled by using the traditional air conditioning refrigeration method, but this method has high cost and lacks economic benefits. Therefore, it is urgent to propose a more economical and effective nitrogen cooling method and device. SUMMARY

[0003] The present application provides a mine zero-energy-consumption self-cooling cold nitrogen generating device and method to solve the above problems.

[0004] The present application adopts the following technical scheme: a mine zero-energy-consumption self-cooling cold nitrogen generating device, comprising a vortex tube connected with a normal-temperature nitrogen source, a cold end tube for discharging low-temperature nitrogen and a hot end tube for discharging high-temperature nitrogen arranged on the vortex tube; a bubble atomization tube, one end of the bubble atomization tube receiving the high-temperature nitrogen discharged by the hot end tube and normal-temperature cooling water provided by a normal-temperature cooling water source, the other end of the bubble atomization tube being connected with a gas-water separator, and outputting nitrogen-fine water mist two-phase flow into the gas-water separator; the gas-water separator discharging high-temperature waste water to a drainage ditch and discharging dry near-normal-temperature nitrogen to a low-temperature nitrogen-near-normal-temperature nitrogen mixing chamber; the low-temperature nitrogen-near-normal-temperature nitrogen mixing chamber receiving the low-temperature nitrogen discharged by the cold end tube and the near-normal-temperature nitrogen discharged by the gas-water separator, and the discharged cold nitrogen being injected into the goaf through an outlet joint.

[0005] The normal-temperature nitrogen supply source comprises a nitrogen generator, the nitrogen generator is connected with a nitrogen buffer tank, a nitrogen switch valve is arranged at the outlet of the nitrogen buffer tank, and the nitrogen buffer tank is connected with a normal-temperature nitrogen conveying pipe through a normal-temperature nitrogen inlet joint; a normal-temperature nitrogen pressure gauge P1, a normal-temperature nitrogen regulating valve, a normal-temperature nitrogen temperature gauge T1, a normal-temperature nitrogen mass flowmeter S1 and a normal-temperature nitrogen pressure gauge P2 are arranged on the normal-temperature nitrogen conveying pipe; and the normal-temperature nitrogen conveying pipe is connected with an air inlet flow channel of the vortex pipe.

[0006] In some embodiments, the normal-temperature cooling water source comprises a mine surface water pool, the mine surface water pool is connected with an underground dustproof pipe network, a cooling water switch valve is arranged at the outlet of the underground dustproof pipe network, and the underground dustproof pipe network is connected with a cooling water conveying pipe through a cooling water inlet joint; a cooling water pressure gauge P4, a cooling water regulating valve, a cooling water temperature gauge T4, a cooling water flowmeter S4 and a cooling water pressure gauge P5 are arranged on the cooling water conveying pipe.

[0007] In some embodiments, the bubble atomization pipe comprises a bubble atomization chamber, one end of the bubble atomization chamber is connected with the high-temperature nitrogen conveying pipe and the cooling water external sleeve, the high-temperature nitrogen conveying pipe extends into the bubble atomization chamber, the other end of the bubble atomization chamber is a bubble atomization nozzle, and the bubble atomization nozzle is connected with the gas-water separator through a connecting head.

[0008] In some embodiments, the gas-water separator is connected with the low-temperature nitrogen-near-normal-temperature nitrogen mixing chamber through a near-normal-temperature nitrogen conveying pipe, and a near-normal-temperature nitrogen temperature gauge T5 is arranged on the near-normal-temperature nitrogen conveying pipe.

[0009] In some embodiments, a cold end outlet temperature gauge T3, a cold end outlet low-temperature nitrogen mass flowmeter S3 and a cold end outlet low-temperature nitrogen pressure gauge P4 are arranged on a connecting pipeline between the cold end pipe and the low-temperature nitrogen-near-normal-temperature nitrogen mixing chamber.

[0010] In some embodiments, the end of the high-temperature nitrogen conveying pipe is embedded in the cooling water external sleeve.

[0011] A use method of a mine zero-energy-consumption self-cooling cold nitrogen generating device, comprising the following steps,

[0012] The vortex pipe automatically separates the normal-temperature nitrogen into two gas flows of high-temperature nitrogen and low-temperature nitrogen;

[0013] The normal-temperature cooling water in the cooling water external sleeve indirectly contacts and performs first-stage cooling treatment on the high-temperature nitrogen, and the atomized normal-temperature cooling water in the bubble atomization pipe directly contacts and performs second-stage cooling treatment on the high-temperature nitrogen, and the generated gas-water mixture is discharged from the bubble atomization nozzle;

[0014] The gas-water mixture is separated in the gas-water separator to obtain near-normal-temperature nitrogen and high-temperature wastewater;

[0015] The low-temperature nitrogen discharged from the vortex tube is mixed with the near-normal-temperature nitrogen in a low-temperature nitrogen-near-normal-temperature nitrogen mixing chamber to generate cold nitrogen.

[0016] The cold nitrogen is discharged through an outlet joint and injected into the goaf.

[0017] The present application uses a vortex tube to automatically separate normal-temperature nitrogen into high-temperature nitrogen and low-temperature nitrogen, uses normal-temperature water in a dust prevention pipe network to indirectly contact and directly contact the high-temperature nitrogen for two-stage cooling treatment to obtain near-normal-temperature nitrogen, and uniformly mixes the near-normal-temperature nitrogen with the low-temperature nitrogen to generate cold nitrogen. The device mainly comprises a vortex tube, a bubble atomization pipe, a gas-water separator, regulating valves, monitoring instruments (pressure, flow rate and temperature), gas-water pipelines and connecting joints.

[0018] The high-temperature nitrogen pipe is embedded in the cooling water pipe to realize the primary cooling of the high-temperature nitrogen through indirect contact with water. The nitrogen after the primary cooling is branched with the cooling water into the bubble atomization pipe to generate nitrogen-fine water mist two-phase flow, and the high-temperature nitrogen is realized secondary cooling through large-area direct contact with the fine water mist. The nitrogen-fine water mist two-phase flow is separated into high-temperature waste water and dry near-normal-temperature nitrogen through the gas-water separator. The high-temperature waste water is discharged to the drainage ditch in the main roadway through the drainage pipe. The dry near-normal-temperature nitrogen is fully mixed with the low-temperature nitrogen discharged from the cold end of the vortex tube to generate cold nitrogen. The cold nitrogen is transported to the coal mine goaf gas using area through the heat preservation pipe.

[0019] The compressed nitrogen at the inlet end of the vortex tube is provided by a nitrogen injection machine, and the gas supply pressure and flow rate are adjustable. The temperature regulating valve is installed at the hot end of the vortex tube, and the temperature and flow rate of the outlet gas flow at the cold end and the temperature and flow rate of the outlet gas flow at the hot end are controlled by adjusting the proportion of the gas flows at the cold end and the hot end. The high-pressure water at the water inlet end of the bubble atomization pipe is provided by the dust prevention pipe network, and the water supply pressure and flow rate are adjustable. During the operation of the device, the optimal nitrogen gas supply pressure and flow rate, the vortex tube hot end pipe outlet flow rate, the cooling water supply pressure and flow rate can be determined according to the temperature, pressure and flow rate of the outlet cold nitrogen. The temperature, pressure and flow rate parameters of the cold nitrogen at the outlet of the device are continuously adjustable within a certain range, and can be monitored in real time. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a kind of mine zero energy consumption self-cooling cold nitrogen generating device internal structure;

[0021] Figure: 1: nitrogen generator, 2: nitrogen buffer tank, 3: nitrogen switch valve, 4: normal temperature nitrogen inlet joint, 5: normal temperature nitrogen conveying pipe, 6: normal temperature nitrogen pressure gauge P1, 7: normal temperature nitrogen regulating valve, 8: normal temperature nitrogen temperature gauge T1, 9: normal temperature nitrogen mass flow meter S1, 10: normal temperature nitrogen pressure gauge P2, 11: vortex tube, 11-1: inlet flow channel, 11-2: vortex chamber, 11-3: separation orifice plate, 11-4: cold end pipe, 11-5: hot end pipe, 11-6: temperature regulating valve, 11-7: hot end silencer, 12: hot end outlet temperature gauge T2, 13: hot end outlet high temperature nitrogen mass flow meter S2, 14: hot end outlet high temperature nitrogen pressure gauge P3, 15: high temperature nitrogen conveying pipe, 16: mine ground water pool, 17: underground dust prevention pipe network, 18: cooling water switch valve, 19: cooling water inlet joint, 20: cooling water conveying pipe, 21: cooling water pressure gauge P4, 22: cooling water regulating valve, 23: cooling water temperature gauge T4, 24: cooling water flow meter S4, 25: cooling water pressure gauge P5, 26: cooling water external sleeve, 27: bubble atomizing pipe, 27-1: bubble atomizing pipe water inlet, 27-2: bubble atomizing pipe air inlet hole, 27-3: bubble atomizing chamber, 27-4: bubble atomizing nozzle, 28: bubble atomizing pipe and air-water separator joint, 29: air-water separator, 29-1: air-water inlet, 29-2: reversing plate, 29-3: liquid separation plate, 29-4: near normal temperature nitrogen outlet, 30: air-water separator and near normal temperature nitrogen conveying pipe joint, 31: cold end outlet temperature gauge T3, 32: cold end outlet low temperature nitrogen mass flow meter S3, 33: cold end outlet low temperature nitrogen pressure gauge P4, 34: near normal temperature nitrogen temperature gauge T5, 35: near normal temperature nitrogen conveying pipe, 36: air-water separator internal high temperature waste water temperature gauge T6, 37: air-water separator high temperature waste water switch valve, 38: high temperature waste water conveying pipe, 39: high temperature waste water outlet joint, 40: main roadway, 41: drainage ditch, 42: cold nitrogen conveying pipe heat preservation sleeve, 43: low temperature nitrogen-near normal temperature nitrogen mixing chamber, 44: cold nitrogen outlet temperature gauge T7, 45: cold nitrogen outlet joint. DETAILED DESCRIPTION

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0023] As Figure 1As shown, a kind of mine zero-energy self-cooling cold nitrogen generating device, including with normal temperature nitrogen supply source connection vortex tube 11, vortex tube 11 is provided with the cold end pipe 11-4 of low-temperature nitrogen gas and the hot end pipe 11-5 of high-temperature nitrogen gas.

[0024] Bubble atomization pipe 27, bubble atomization pipe 27 one end receives the high-temperature nitrogen gas of hot end pipe 11-5 discharge and the normal temperature cooling water provided by normal temperature cooling water source, the other end is connected with gas-water separator 29, and nitrogen gas-fine water mist two-phase flow is exported to gas-water separator 29.

[0025] Gas-water separator 29 discharges high-temperature wastewater to drain ditch 41, and dry near-normal temperature nitrogen gas is discharged to low-temperature nitrogen-near-normal temperature nitrogen gas mixing chamber 43.

[0026] Low-temperature nitrogen-near-normal temperature nitrogen gas mixing chamber 43 receives the low-temperature nitrogen gas of cold end pipe 11-4 discharge and the near-normal temperature nitrogen gas of gas-water separator 29 discharge, and low-temperature nitrogen-near-normal temperature nitrogen gas mixing chamber 43 discharges cold nitrogen and is injected into goaf through outlet joint 45.

[0027] Normal temperature nitrogen supply source includes nitrogen generator 1, nitrogen generator 1 is connected with nitrogen buffer tank 2, nitrogen buffer tank 2 is provided with nitrogen switch valve 3 at the outlet, and is connected with normal temperature nitrogen gas inlet joint 4 and normal temperature nitrogen gas conveying pipe 5 by normal temperature nitrogen gas, normal temperature nitrogen gas conveying pipe 5 is provided with normal temperature nitrogen gas pressure gauge P16, normal temperature nitrogen gas regulating valve 7, normal temperature nitrogen gas temperature table T18, normal temperature nitrogen gas mass flow meter S19, normal temperature nitrogen gas pressure gauge P210, and normal temperature nitrogen gas conveying pipe 5 is connected with the air inlet channel 11-1 of vortex tube 11.

[0028] Normal temperature cooling water source includes mine surface water pool 16, mine surface water pool 16 is connected with underground dust prevention pipe network 17, cooling water switch valve 18 is arranged at the outlet of underground dust prevention pipe network 17, and is connected with cooling water inlet joint 19 and cooling water conveying pipe 20, cooling water conveying pipe 20 is provided with cooling water pressure gauge P421, cooling water regulating valve 22, cooling water temperature table T423, cooling water flow meter S424 and cooling water pressure gauge P525.

[0029] Bubble atomization pipe 27 includes bubble atomization chamber 27-3, bubble atomization chamber 27-3 one end is provided with bubble atomization pipe water inlet 27-1 and bubble atomization pipe air inlet hole 27-2 (located at the end of high-temperature nitrogen gas conveying pipe 15), and the other end of bubble atomization chamber 27-3 is bubble atomization nozzle 27-4, bubble atomization nozzle 27-4 is connected with gas-water separator 29 through bubble atomization pipe and gas-water separator connecting head 28.

[0030] Gas-water separator 29 is connected with low-temperature nitrogen-near-normal temperature nitrogen gas mixing chamber 43 through near-normal temperature nitrogen gas conveying pipe 35, and near-normal temperature nitrogen gas temperature table T534 is arranged on near-normal temperature nitrogen gas conveying pipe 35.

[0031] A cold end outlet temperature table T331, a cold end outlet low-temperature nitrogen mass flow meter S332, and a cold end outlet low-temperature nitrogen pressure gauge P433 are arranged on a connecting pipeline between the cold end pipe 11-4 and the low-temperature nitrogen-near-normal-temperature nitrogen mixing chamber 43.

[0032] A use method of the mine zero-energy-consumption self-cooling cold nitrogen generating device, comprising the following steps:

[0033] The nitrogen buffer tank 2 is connected with the normal-temperature nitrogen inlet joint 4 of the device, the underground dustproof pipe network 17 is connected with the cooling water inlet joint 19 of the device, and the drainage ditch 41 is connected with the warm waste water outlet joint. The nitrogen switch valve 3, the cooling water switch valve 18, and the gas-water separator high-temperature waste water switch valve 37 are opened.

[0034] After the normal-temperature nitrogen enters the vortex pipe 11, it is discharged through the cold end pipe 11-4 and the hot end pipe 11-5 respectively. By adjusting the normal-temperature nitrogen regulating valve 7 and the temperature regulating valve 11-6, the temperature of the nitrogen at the outlet of the cold end pipe 11-4 and the hot end pipe 11-5 is changed.

[0035] The cooling water pressure source of the device is provided by the mine ground pool 16. The cooling water enters the cooling water external sleeve 26 through the underground dustproof pipe network 17, the cooling water switch valve 18, the cooling water inlet joint 19, and the cooling water conveying pipe 20.

[0036] After the gas flow in the hot end pipe 11-5 is processed by the hot end silencer 11-7, the high-temperature nitrogen gas enters the cooling water external sleeve 26 through the high-temperature nitrogen conveying pipe 15, and is initially cooled under the indirect contact of the cooling water.

[0037] After the initial cooling, the high-temperature nitrogen gas enters the bubble atomization pipe 27, and is discharged to the bubble atomization chamber 27-3 through the bubble atomization pipe gas inlet hole 27-2. The cooling water enters the bubble atomization chamber 27-3 through the bubble atomization pipe water inlet hole 27-1. In the bubble atomization chamber 27-3, a large number of liquid droplets and liquid lines wrapped in gas bubbles are generated by the strong shearing and tearing action of the high-temperature nitrogen gas, so that the cooling water is atomized for the first time. The nitrogen gas bubbles wrapped in the cooling water "explode" under the action of the internal and external pressure difference after being sprayed out of the bubble atomization nozzle 27-4, so that the cooling water is atomized for the second time. Through the two times of atomization of the cooling water, the nitrogen gas-fine water mist two-phase flow is formed, so that the high-temperature nitrogen gas and the cooling water are fully contacted, and the heat in the nitrogen gas is forced to be conducted to the cooling water.

[0038] The nitrogen gas-fine water mist two-phase flow enters the gas-water separator 29 through the bubble atomization pipe and the gas-water separator connecting joint 28, and the gas-water inlet 29-1. After the separation action of the gas-water separator 29, dry near-normal-temperature nitrogen gas and high-temperature waste water are discharged.

[0039] The high-temperature waste water is discharged into the drainage ditch 41 in the main roadway 40 through the gas-water separator high-temperature waste water switch valve 37, the high-temperature waste water conveying pipe 38 and the high-temperature waste water outlet joint 39.

[0040] The near-normal-temperature nitrogen gas enters the low-temperature nitrogen gas-near-normal-temperature nitrogen gas mixing chamber 43 through the near-normal-temperature nitrogen gas outlet 29-4, the gas-water separator and the near-normal-temperature nitrogen gas conveying pipe joint 30, the near-normal-temperature nitrogen gas conveying pipe 35, and is mixed with the low-temperature nitrogen gas to form cold nitrogen.

[0041] The cold nitrogen is discharged through the outlet joint 45 and injected into the goaf. The cold nitrogen conveying pipe is wrapped with a heat preservation sleeve.

[0042] During the operation of the whole device, the normal-temperature nitrogen gas pressure and flow, the cold end pipe and hot short pipe temperature, the cooling water pressure and flow are continuously adjustable, and the related parameters can be displayed on the panel of the device.

[0043] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A zero-energy-consumption self-cooling cold nitrogen generator for mining, characterized in that: It includes a vortex tube (11) connected to a room temperature nitrogen supply source, and the vortex tube (11) is provided with a cold end tube (11-4) for discharging low temperature nitrogen and a hot end tube (11-5) for discharging high temperature nitrogen. The bubble atomizing tube (27) receives high-temperature nitrogen gas discharged from the hot end tube (11-5) and room-temperature cooling water provided by the room-temperature cooling water source at one end, and the other end is connected to the gas-water separator (29), outputting nitrogen gas-fine water mist two-phase flow into the water separator (29); The gas-water separator (29) discharges high-temperature wastewater to the drainage ditch (41) and discharges dry near-room temperature nitrogen to the low-temperature nitrogen-near-room temperature nitrogen mixing chamber (43). The low-temperature nitrogen-near-normal temperature nitrogen mixing chamber (43) receives the low-temperature nitrogen discharged from the cold end pipe (11-4) and the near-normal temperature nitrogen discharged from the water separator (29). The discharged cold nitrogen is injected into the goaf area through the outlet connector (45). The bubble atomizing tube (27) includes a bubble atomizing chamber (27-3). One end of the bubble atomizing chamber (27-3) is provided with a bubble atomizing tube water inlet (27-1) and a bubble atomizing tube air inlet (27-2). The bubble atomizing tube air inlet (27-2) is located at the end of the high-temperature nitrogen delivery tube (15). The other end of the bubble atomizing chamber (27-3) is a bubble atomizing nozzle (27-4). The bubble atomizing nozzle (27-4) is connected to the gas-water separator (29) through the bubble atomizing tube and gas-water separator connector (28). The end section of the high-temperature nitrogen delivery pipe (15) is embedded in the cooling water outer sleeve (26).

2. The zero-energy-consumption self-cooling nitrogen generator for mining as described in claim 1, characterized in that: The ambient temperature nitrogen supply source includes a nitrogen generator (1), which is connected to a nitrogen buffer tank (2). The outlet of the nitrogen buffer tank (2) is equipped with a nitrogen switch valve (3) and is connected to an ambient temperature nitrogen delivery pipe (5) through an ambient temperature nitrogen inlet connector (4). The ambient temperature nitrogen delivery pipe (5) is equipped with an ambient temperature nitrogen pressure gauge P1 (6), an ambient temperature nitrogen regulating valve (7), an ambient temperature nitrogen temperature gauge T1 (8), an ambient temperature nitrogen mass flow meter S1 (9), and an ambient temperature nitrogen pressure gauge P2 (10). The ambient temperature nitrogen delivery pipe (5) is connected to the inlet channel (11-1) of the vortex tube (11).

3. The zero-energy-consumption self-cooling nitrogen generator for mining according to claim 1, characterized in that: The ambient temperature cooling water source includes a mine surface water tank (16), which is connected to the underground dust control network (17). A cooling water switch valve (18) is installed at the outlet of the underground dust control network (17), and is connected to the cooling water delivery pipe (20) through a cooling water inlet connector (19). The cooling water delivery pipe (20) is equipped with a cooling water pressure gauge P4 (21), a cooling water regulating valve (22), a cooling water temperature gauge T4 (23), a cooling water flow meter S4 (24), and a cooling water pressure gauge P5 (25).

4. The zero-energy-consumption self-cooling nitrogen generator for mining according to claim 1, characterized in that: The gas-water separator (29) is connected to the low-temperature nitrogen-near-room temperature nitrogen mixing chamber (43) via a near-room temperature nitrogen delivery pipe (35), and a near-room temperature nitrogen thermometer T5 (34) is installed on the near-room temperature nitrogen delivery pipe (35).

5. The zero-energy-consumption self-cooling nitrogen generator for mining according to claim 1, characterized in that: The cold end pipe (11-4) and the low-temperature nitrogen-near-room temperature nitrogen mixing chamber (43) are connected by a cold end outlet temperature gauge T3 (31), a cold end outlet low-temperature nitrogen mass flow meter S3 (32), and a cold end outlet low-temperature nitrogen pressure gauge P4 (33).

6. A method of using the zero-energy-consumption self-cooling nitrogen generator for mining as described in claim 1, characterized in that: Includes the following steps, The vortex tube (11) automatically separates room temperature nitrogen into two streams: high temperature nitrogen and low temperature nitrogen. In the cooling water outer sleeve (26), ambient temperature cooling water indirectly contacts high temperature nitrogen for primary cooling treatment, while in the bubble atomizing tube (27), ambient temperature cooling water directly contacts high temperature nitrogen for secondary cooling treatment, and the generated gas-water mixture is discharged through the bubble atomizing nozzle (27-4). The gas-water mixture is separated into near-room temperature nitrogen and high temperature wastewater in the gas-water separator (29); Near-room temperature nitrogen and low-temperature nitrogen discharged from the vortex tube (11) are uniformly mixed in the low-temperature nitrogen-near-room temperature nitrogen mixing chamber (43) to generate cold nitrogen; Cold nitrogen is discharged through the outlet connector (45) and then injected into the goaf.

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