阅读说明：本技术 一种新型液氮、液态二氧化碳防灭火系统及方法 (Novel liquid nitrogen and liquid carbon dioxide fire preventing and extinguishing system and method ) 是由 陈付坤 宋亮 陈春雷 田国徽 刘传滨 侯玉文 于 2021-08-06 设计创作，主要内容包括：本发明涉及一种新型液氮、液态二氧化碳防灭火系统及方法,属于防灭火技术领域。技术方案是：液氮低温储罐(1)底部与液氮储罐出液管口(2)连通后分为两路,一路通过储罐自增压装置连接与液氮低温储罐(1)顶部的气相空间连接,使液氮低温储罐(1)压力升高,另一路通过低压液氮管路(4)连接到增压装置(5),增压装置(5)与气化装置(8)连接,气化装置(8)与电加热辅热装置(12)连接,电加热辅热装置(12)与稳压稳流装置(15)连接,稳压稳流装置(15)与用户总管(21)连接。本发明的积极效果：可满足用户和环境等多个因素影响下的气体流量和压力需求,且能保证气量的稳定供应。(The invention relates to a novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing system and method, and belongs to the technical field of fire prevention and extinguishing. The technical scheme is as follows: the bottom of the liquid nitrogen low-temperature storage tank (1) is communicated with a liquid outlet pipe orifice (2) of the liquid nitrogen storage tank and then divided into two paths, one path is connected with a gas phase space at the top of the liquid nitrogen low-temperature storage tank (1) through a storage tank self-pressurization device to enable the pressure of the liquid nitrogen low-temperature storage tank (1) to rise, the other path is connected to a pressurization device (5) through a low-pressure liquid nitrogen pipeline (4), the pressurization device (5) is connected with a gasification device (8), the gasification device (8) is connected with an electric heating auxiliary heating device (12), the electric heating auxiliary heating device (12) is connected with a voltage-stabilizing and current-stabilizing device (15), and the voltage-stabilizing and current-stabilizing device (15) is connected with a user header pipe (21). The invention has the following positive effects: the gas flow and pressure requirements under the influence of a plurality of factors such as users and environment can be met, and stable supply of gas quantity can be ensured.)

1. The utility model provides a novel liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing systems which characterized in that: at least comprises the following components: the system comprises a liquid nitrogen low-temperature storage tank (1), a liquid carbon dioxide storage tank (22), a supercharging device (5), a storage tank self-supercharging device, an air diffusing and heating device, a gasification device (8), a pressure and flow stabilizing device (15), an electric heating auxiliary heating device (12) and a metering device (19); the bottom of the liquid nitrogen low-temperature storage tank (1) is communicated with a liquid outlet pipe orifice (2) of the liquid nitrogen storage tank and then divided into two paths, one path is connected with a gas phase space at the top of the liquid nitrogen low-temperature storage tank (1) through a storage tank self-pressurization device to enable the pressure of the liquid nitrogen low-temperature storage tank (1) to be increased, the other path is connected with a pressurization device (5) through a low-pressure liquid nitrogen pipeline (4), the pressurization device (5) is connected with a gas return port at the top of the liquid nitrogen low-temperature storage tank (1) through a gas return pipeline (6), an air-to-air dissipation heating device is arranged at the top of the liquid nitrogen low-temperature storage tank (1), a liquid carbon dioxide storage tank (22) is connected with the pressurization device (5) through a carbon dioxide liquid outlet pipeline (23), the pressurization device (5) is connected with a gasification device (8) through a high-pressure pipeline (7), and the gasification device (8) is connected with an electric heating auxiliary heating device (12) through a gasification device gas outlet pipeline (9), the electric heating auxiliary heating device (12) is connected with the voltage-stabilizing and current-stabilizing device (15) through an auxiliary heating device air outlet pipeline (14), the voltage-stabilizing and current-stabilizing device (15) is connected with the user main pipe (21) through a voltage-stabilizing and current-stabilizing device air outlet pipeline (16), and the metering device (19) is arranged on the voltage-stabilizing and current-stabilizing device air outlet pipeline (16).

2. The liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing system according to claim 1, characterized in that: the storage tank is from supercharging device contains at least and opens valve (25), from supercharging vaporizer (26), voltage regulator (27) and from supercharging gas pipeline (28) from the pressure boost, liquid nitrogen storage tank goes out liquid pipe mouth (2) all the way and is connected from supercharging gas pipeline (28), is equipped with in proper order on supercharging gas pipeline (28) and opens valve (25), from supercharging vaporizer (26) and voltage regulator (27) from the pressure boost.

3. A novel liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing system according to claim 1 or 2, characterized in that: the air diffusing heating device at least comprises a gas discharge pipe orifice (35), a gas discharge valve (29), a diffusing gas inlet pipeline (30), a diffusing heating device (31), a diffusing gas outlet pipeline (32), a temperature detector (33) and a diffusing gas outlet (34), wherein the gas discharge pipe orifice (35) is arranged at the top of the liquid nitrogen low-temperature storage tank (1), the gas discharge pipe orifice (35) is connected with the diffusing gas inlet pipeline (30) through the gas discharge valve (29), the diffusing gas outlet (34) of the diffusing gas inlet pipeline (30) is communicated with the outside, and the diffusing gas inlet pipeline (30) is sequentially provided with the diffusing heating device (31), the diffusing gas outlet pipeline (32) and the temperature detector (33).

4. A novel liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing system according to claim 1 or 2, characterized in that: the gasification device gas outlet pipeline (9) is divided into two paths through a multi-path valve of the auxiliary heating device, one path is connected with the voltage-stabilizing and current-stabilizing device (15) through an electric heating auxiliary heating device bypass pipeline (13), and the other path is connected with the electric heating auxiliary heating device (12) through an auxiliary heating device gas inlet pipeline (11) and then connected with the voltage-stabilizing and current-stabilizing device (15).

5. A novel liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing system according to claim 1 or 2, characterized in that: the gas outlet pipeline (16) of the pressure-stabilizing and flow-stabilizing device is divided into two paths through a metering device multi-way valve (17), one path is connected with a user main pipe (21) through a metering device bypass pipeline, and the other path is connected with the user main pipe (21) through a first cut-off valve (18A), a metering device (19) and a second cut-off valve (18B) in sequence.

6. A novel liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing system according to claim 1 or 2, characterized in that: the supercharging device (5) is a liquid nitrogen pump.

7. A novel liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing system according to claim 1 or 2, characterized in that: the pressure and flow stabilizing device (15) is a pressure stabilizing tank.

8. A novel liquid nitrogen, liquid carbon dioxide fire prevention and extinguishing system according to claim 1 or 2, characterized in that: a liquid nitrogen outlet pipe orifice valve is arranged on the liquid nitrogen storage tank liquid outlet pipe orifice (2); a carbon dioxide liquid outlet valve (24) is arranged on the carbon dioxide liquid outlet pipeline (23); a nitrogen purging device is arranged on the gasification device (8).

9. A novel method for preventing and extinguishing fire by liquid nitrogen and liquid carbon dioxide, which adopts the fire preventing and extinguishing system defined by any one of claims 1 to 8, and is characterized in that:

when liquid nitrogen is needed to be used for fire prevention and extinguishment, liquid nitrogen in a liquid nitrogen low-temperature storage tank (1) is divided into two paths through a liquid outlet pipe orifice (2) of the liquid nitrogen storage tank, one path of liquid nitrogen enters a gas phase space at the top of the liquid nitrogen low-temperature storage tank (1) after being gasified and stabilized by a storage tank self-pressurization device, the pressure in the liquid nitrogen low-temperature storage tank (1) is increased, and normal transportation and distribution of the liquid nitrogen are ensured; the other path of liquid nitrogen flows to a supercharging device (5) through a low-pressure liquid nitrogen pipeline (4), the supercharging device (5) pressurizes the liquid nitrogen, the liquid nitrogen is pressurized to a set pressure and then enters a gasification device (8) through a high-pressure pipeline (7) to be gasified to form nitrogen, the pressure and the flow of the supercharging device (5) can be adjusted, a small amount of low-temperature gas can be generated in the operation process of the supercharging device (5), and in order to ensure the pressure balance and the fluctuation reduction in the operation liquid nitrogen low-temperature storage tank (1), the low-temperature gas generated by the supercharging device (5) returns to a gas return port at the top of the liquid nitrogen low-temperature storage tank (1) through a gas return pipeline (6); when the nitrogen does not need to be heated, the nitrogen enters the bypass pipeline (13) of the electric heating auxiliary heat device, is subjected to pressure stabilization through the pressure stabilizing and flow stabilizing device (15), passes through the air outlet pipeline (16) of the pressure stabilizing and flow stabilizing device and then is connected with the user main pipe (21); when the nitrogen needs to be heated, the nitrogen enters the air inlet pipeline (11) of the auxiliary heating device to be heated, and the heated nitrogen is stabilized by the pressure stabilizing and flow stabilizing device (15), then passes through the air outlet pipeline (16) of the pressure stabilizing and flow stabilizing device and then is connected with the user header pipe (21); when the nitrogen needs to be metered, opening a first cut-off valve (18A) and a second cut-off valve (18B), enabling the nitrogen to enter a metering device for metering, and enabling the metered nitrogen to enter a user header pipe (21); when the nitrogen does not need to be metered, the first shut-off valve (18A) and the second shut-off valve (18B) are closed, and the nitrogen enters a user header pipe (21) through a metering device bypass pipeline (20);

secondly, when the liquid carbon dioxide is needed to prevent and extinguish the fire, the gasification device (8) is subjected to low-pressure nitrogen purging by the nitrogen purging device, after purging, opening a carbon dioxide liquid outlet valve (24), enabling liquid carbon dioxide in a liquid carbon dioxide storage tank (22) to enter a pressurizing device (5) through a carbon dioxide liquid outlet pipeline (23), pressurizing the liquid carbon dioxide by the pressurizing device (5), enabling the liquid carbon dioxide to enter a gasification device (8) through a high-pressure pipeline (7) after being pressurized to a set pressure to be gasified to form a carbon dioxide gas source, enabling the pressure and the flow of the pressurizing device (5) to be adjustable, enabling the carbon dioxide gas source to enter an electric heating auxiliary heat device bypass pipeline (13) through a gasification device gas outlet pipeline (9), after being stabilized by the pressure stabilizing and flow stabilizing device (15), the pressure stabilizing and flow stabilizing device is connected with a user main pipe (21) through an air outlet pipeline (16) of the pressure stabilizing and flow stabilizing device; when the carbon dioxide gas source needs to be metered, the first cut-off valve (18A) and the second cut-off valve (18B) are opened, the carbon dioxide gas source enters the metering device for metering, and the metered carbon dioxide gas source enters the user main pipe (21); when the carbon dioxide gas source does not need to be metered, the first cut-off valve (18A) and the second cut-off valve (18B) are closed by the pipe, and the carbon dioxide gas source enters the user main pipe (21) through the metering device bypass pipeline (20).

10. The novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing method according to claim 9 is characterized by comprising the following specific steps of:

when the liquid nitrogen low-temperature storage tank (1) is used, the pressure in the liquid nitrogen low-temperature storage tank (1) is reduced, and in order to ensure normal transportation and distribution of liquid nitrogen, a storage tank self-pressurization device is adopted to pressurize the liquid nitrogen low-temperature storage tank (1); the tank self-pressurization device at least comprises: the device comprises a self-pressurization gasifier (26), a self-pressurization opening valve (25), a pressure regulator (27) and a pressurization gas pipeline (28), wherein liquid nitrogen in a liquid nitrogen low-temperature storage tank (1) is led out from a liquid outlet pipe orifice (2) of the liquid nitrogen storage tank, then the liquid nitrogen is gasified into nitrogen gas by the self-pressurization gasifier (26), the pressure of the nitrogen gas is regulated by the pressure regulator (27) to be stabilized at the same pressure as the internal pressure of the liquid nitrogen low-temperature storage tank (1), and then the nitrogen gas is sent back to a gas phase space at the top of the liquid nitrogen low-temperature storage tank (1) through the self-pressurization gas pipeline (28), so that the pressure of the liquid nitrogen low-temperature storage tank (1) is increased;

the air diffusing system at least comprises a gas discharge pipe orifice (35), a gas discharge valve (29), a diffusing gas inlet pipeline (30), a diffusing heating device (31), a diffusing gas outlet pipeline (32), a temperature detector (33) and a diffusing gas outlet (34), when the pressure in the liquid nitrogen low-temperature storage tank (1) under the non-operation working condition is higher than the set pressure, the gas discharge valve (29) on the gas discharge pipe orifice (35) at the top of the liquid nitrogen low-temperature storage tank (1) is automatically opened, the low-temperature gas in the tank body is discharged to the diffusing heating device (31) to be heated, and then the low-temperature gas is discharged into an atmospheric system; when the pressure in the liquid nitrogen low-temperature storage tank (1) is lower than the set pressure, a gas discharge valve (29) on the storage tank is automatically closed; when the temperature detector (33) at the outlet of the diffusion heating device (31) displays a temperature 5 ℃ lower than the ambient temperature, the opening degree of the gas discharge valve (29) is appropriately reduced.

Technical Field

The invention relates to a novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing system and method, and belongs to the technical field of fire prevention and extinguishing.

Background

Mine fires pose great threats to coal mine safety production, mines with natural fire risks in important coal mines in China account for about 50%, and fires caused by spontaneous combustion account for more than 90% of total fires. Conventional fire prevention and extinguishing techniques such as sand grouting, gelling, stopping agents, foaming, etc. have the disadvantages of consuming a large amount of silt or water, having poor permeability and diffusivity, limited coverage area, deteriorating the working environment in the well, affecting the quality of coal, corroding equipment in the well, etc. At present, liquid nitrogen gasification is used for fire prevention and extinguishment, and the liquid nitrogen gasification is gradually applied to various large coal mines, so that nitrogen extinguishment can quickly extinguish a large fire area of tens of thousands of meters and can inhibit combustible gas explosion in the fire area; liquid nitrogen can absorb a large amount of heat in the gasification process, can cool the goaf environment temperature fast, greatly shorten the time of goaf float coal oxidation, improve the security in the extinguishing process. However, the existing liquid nitrogen fire prevention and extinguishing system for coal mines generally has the problems of insufficient air source pressure and flow, poor pressure and flow stability, poor system stability, overlarge pressure drop in the conveying process, insufficient heat required during gasification, single applicable medium, increased fire extinguishing time, obvious reduction of cooling and fire extinguishing effects and the like.

Disclosure of Invention

The invention aims to provide a novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing system and a method, which have the advantages of continuous and stable fire extinguishing pressure and flow, no pressure drop of the system, stable gasification amount, suitability for fire extinguishing sites of large coal mine goafs, suitability for liquid nitrogen, liquid carbon dioxide and other media, and capability of solving the problems in the background art.

The technical scheme of the invention is as follows:

a novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing system at least comprises: the system comprises a liquid nitrogen low-temperature storage tank, a liquid carbon dioxide storage tank, a supercharging device, a storage tank self-supercharging device, an air diffusing and heating device, a gasification device, a voltage-stabilizing and current-stabilizing device, an electric heating auxiliary heating device and a metering device; the device comprises a liquid nitrogen low-temperature storage tank, a liquid nitrogen storage tank, a pressurizing device, an electric heating auxiliary heating device, a pressure stabilizing and flow stabilizing device and a metering device, wherein the bottom of the liquid nitrogen low-temperature storage tank is communicated with a liquid outlet pipe orifice of the liquid nitrogen storage tank and then divided into two paths, one path of the liquid nitrogen low-temperature storage tank is connected with a gas phase space at the top of the liquid nitrogen low-temperature storage tank through a storage tank self-pressurizing device to enable the pressure of the liquid nitrogen low-temperature storage tank to rise, the other path of the liquid nitrogen low-temperature storage tank is connected with the pressurizing device through a low-pressure liquid nitrogen pipeline, the pressurizing device is connected with a gas return port at the top of the liquid nitrogen low-temperature storage tank through a gas return pipeline, the top of the liquid nitrogen low-temperature storage tank is provided with an air-release heating device, the liquid carbon dioxide storage tank is connected with the pressurizing device through a carbon dioxide liquid outlet pipeline, the pressurizing device is connected with a gasification device through a high-pressure pipeline, the gasification device is connected with the electric heating auxiliary heating device through an air outlet pipeline, the electric heating auxiliary heating device is connected with a pressure stabilizing and flow stabilizing device, and flow stabilizing device is arranged on the gas outlet pipeline.

The storage tank is from supercharging device contains from the pressure boost open valve, from pressure boost vaporizer, voltage regulator and from the pressure boost gas pipeline, liquid nitrogen storage tank goes out the orificial all the way and is connected with from the pressure boost gas pipeline, is equipped with in proper order on the pressure boost gas pipeline from the pressure boost open valve, from pressure boost vaporizer and voltage regulator.

The air diffusing heating device comprises a gas discharge pipe orifice, a gas discharge valve, a diffusing gas inlet pipeline, a diffusing heating device, a diffusing gas outlet pipeline, a temperature meter and a diffusing gas outlet, wherein the gas discharge pipe orifice is arranged at the top of the liquid nitrogen low-temperature storage tank, the gas discharge pipe orifice is connected with the diffusing gas inlet pipeline through the gas discharge valve, the diffusing gas outlet of the diffusing gas inlet pipeline is communicated with the outside, and the diffusing gas inlet pipeline is sequentially provided with the diffusing heating device, the diffusing gas outlet pipeline and the temperature meter.

The gasification device gas outlet pipeline is divided into two paths through a multi-path valve of the auxiliary heating device, one path is connected with the voltage and current stabilizing device through a bypass pipeline of the electric heating auxiliary heating device, and the other path is connected with the voltage and current stabilizing device after being connected with the electric heating auxiliary heating device through an air inlet pipeline of the auxiliary heating device.

The air outlet pipeline of the pressure and flow stabilizing device is divided into two paths through a metering device and a multi-path valve, one path is connected with the user header pipe through a metering device bypass pipeline, and the other path is connected with the user header pipe through a first cut-off valve, a metering device and a second cut-off valve in sequence.

The supercharging device is a liquid nitrogen pump.

The pressure and flow stabilizing device is a pressure stabilizing tank.

A liquid nitrogen outlet pipe orifice valve is arranged on the liquid nitrogen storage tank liquid outlet pipe orifice; a carbon dioxide outlet valve is arranged on the carbon dioxide outlet pipeline; the gasification device is provided with a nitrogen purging device.

A novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing method adopts the fire prevention and extinguishing system and comprises the following steps:

when liquid nitrogen is needed to be used for fire prevention and extinguishment, liquid nitrogen in a liquid nitrogen low-temperature storage tank is divided into two paths through a liquid outlet pipe orifice of a liquid nitrogen storage tank, one path of liquid nitrogen enters a gas phase space at the top of the liquid nitrogen low-temperature storage tank after being gasified and stabilized by a storage tank self-pressurization device, the pressure in the liquid nitrogen low-temperature storage tank is increased, and normal transportation and distribution of the liquid nitrogen are ensured; the other path of liquid nitrogen flows to a supercharging device through a low-pressure liquid nitrogen pipeline, the supercharging device pressurizes the liquid nitrogen, the liquid nitrogen is pressurized to a set pressure and then enters a gasification device through a high-pressure pipeline to be gasified to form nitrogen, the pressure and the flow of the supercharging device can be adjusted, the supercharging device can generate a small amount of low-temperature gas in the operation process, and in order to ensure the pressure balance and reduce fluctuation in the operation liquid nitrogen low-temperature storage tank, the low-temperature gas generated by the supercharging device flows back to a gas return port at the top of the liquid nitrogen low-temperature storage tank through a gas return pipeline; when the nitrogen does not need to be heated, the nitrogen enters the bypass pipeline of the electric heating auxiliary heat device, is stabilized by the voltage stabilizing and current stabilizing device and then is connected with the user main pipe after passing through the gas outlet pipeline of the voltage stabilizing and current stabilizing device; when the nitrogen needs to be heated, the nitrogen enters the air inlet pipeline of the auxiliary heating device to be heated, and the heated nitrogen is stabilized by the pressure stabilizing and flow stabilizing device and then is connected with the user header pipe after passing through the air outlet pipeline of the pressure stabilizing and flow stabilizing device; when the nitrogen needs to be metered, opening the first stop valve and the second stop valve, metering the nitrogen in the metering device, and feeding the metered nitrogen into a user main pipe; when the nitrogen does not need to be measured, the first pipe shut-off valve and the second pipe shut-off valve are used, and the nitrogen enters the user main pipe through the metering device bypass pipeline;

when liquid carbon dioxide is needed to be used for fire prevention and extinguishment, low-pressure nitrogen purging is carried out on the gasification device through the nitrogen purging device, after purging, a carbon dioxide liquid outlet valve is opened, liquid carbon dioxide in the liquid carbon dioxide storage tank enters the pressurizing device through the carbon dioxide liquid outlet pipeline, the pressurizing device pressurizes the liquid carbon dioxide, after the liquid carbon dioxide is pressurized to a set pressure, the liquid carbon dioxide enters the gasification device through the high-pressure pipeline to be gasified to form a carbon dioxide gas source, the pressure and the flow of the pressurizing device can be adjusted, the carbon dioxide gas source enters the electric heating auxiliary heating device bypass pipeline through the gasification device gas outlet pipeline, and after being stabilized by the pressure stabilizing and flow stabilizing device, the carbon dioxide gas source is connected with a user main pipe through the pressure stabilizing and flow stabilizing device gas outlet pipeline; when the carbon dioxide gas source needs to be metered, opening the first stop valve and the second stop valve, metering the carbon dioxide gas source in the metering device, and feeding the metered carbon dioxide gas source into the user main pipe; when the carbon dioxide gas source does not need to be metered, the first cut-off valve and the second cut-off valve are closed by the pipe, and the carbon dioxide gas source enters the user main pipe through the bypass pipeline of the metering device.

When the liquid nitrogen low-temperature storage tank is used, the pressure in the liquid nitrogen low-temperature storage tank is reduced, and in order to ensure normal transportation and distribution of liquid nitrogen, a storage tank self-pressurization device is adopted to pressurize the liquid nitrogen low-temperature storage tank; the tank self-pressurization device at least comprises: the system comprises a self-pressurization gasifier, a self-pressurization opening valve, a pressure regulator and a pressurization gas pipeline, wherein liquid nitrogen in a liquid nitrogen low-temperature storage tank is led out from a liquid outlet pipe orifice of a liquid nitrogen storage tank and then is converted into nitrogen by the self-pressurization gasifier, the pressure of the nitrogen is regulated by the pressure regulator to be stabilized at the same pressure as the pressure inside the liquid nitrogen low-temperature storage tank, and the nitrogen is sent back to a gas phase space at the top of the liquid nitrogen low-temperature storage tank through the self-pressurization gas pipeline to increase the pressure of the liquid nitrogen low-temperature storage tank;

when the pressure in the liquid nitrogen low-temperature storage tank under the non-operation working condition is higher than the set pressure, the gas discharge valve on the gas discharge pipe opening at the top of the liquid nitrogen low-temperature storage tank is automatically opened, the low-temperature gas in the tank body is discharged to the diffusion heating device for heating, and then is discharged into an atmospheric system; when the pressure in the liquid nitrogen low-temperature storage tank is lower than the set pressure, a gas discharge valve on the storage tank is automatically closed; when the temperature detector at the outlet of the diffusion heating device displays that the temperature is 5 ℃ lower than the ambient temperature, the opening of the gas discharge valve is properly reduced.

The invention has the following positive effects: 1. the supercharging device with adjustable flow and pressure is added among the liquid nitrogen low-temperature storage tank, the liquid carbon dioxide storage tank and the gasification device, so that the gas flow and pressure requirements under the influence of a plurality of factors such as users and environment can be met, and the stable supply of gas quantity can be ensured. 2. The storage tank self-pressurization device is adopted to convey the gasified nitrogen to the gas phase space of the liquid nitrogen low-temperature storage tank, so that the pressure stability of the liquid nitrogen in the storage tank is ensured, and the automatic pressure stabilization can be realized according to the pressure change in the storage tank. 3. The air diffusing heating device with the heating function is added, the air diffusing heating device can be automatically opened and closed according to the pressure change in the liquid nitrogen low-temperature storage tank, and can automatically heat the discharged low-temperature nitrogen gas to prevent the low temperature from freezing to cause the frostbite of personnel. 4. The system is provided with a pressure-stabilizing and flow-stabilizing device to ensure the stability of gas supply for users. 5. In order to ensure the use requirement of cold regions, an electric heating auxiliary heating device is added for heating gasified gas and ensuring the safety and reliability of gas use.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention;

in the figure: 1-a liquid nitrogen low-temperature storage tank, 2-a liquid nitrogen storage tank liquid outlet pipe orifice, 3-a liquid nitrogen liquid outlet pipe orifice valve, 4-a low-pressure liquid nitrogen pipeline, 5-a supercharging device, 6-a gas return pipeline, 7-a high-pressure pipeline, 8-a gasification device, 9-a gasification device gas outlet pipeline, 10-an auxiliary heat device multi-way valve, 11-an auxiliary heat device gas inlet pipeline, 12-an electric heating auxiliary heat device, 13-an electric heating auxiliary heat device bypass pipeline, 14-an auxiliary heat device gas outlet pipeline, 15-a pressure stabilizing and flow stabilizing device, 16-a pressure stabilizing and flow stabilizing device gas outlet pipeline, 17-a metering device multi-way valve, 18A-a first cut-off valve, 18B-a second cut-off valve, 19-a metering device, 20-a metering device bypass pipeline, 21-a user main pipe and 22-a liquid carbon dioxide storage tank, 23-a carbon dioxide liquid outlet pipeline, 24-a carbon dioxide liquid outlet valve, 25-a self-pressurization opening valve, 26-a self-pressurization gasifier, 27-a pressure regulator, 28-a self-pressurization gas pipeline, 29-a gas discharge valve, 30-a diffusion gas inlet pipeline, 31-a diffusion heating device, 32-a diffusion gas outlet pipeline, 33-a temperature detector, 34-a diffusion gas outlet and 35-a gas discharge pipe orifice.

Detailed Description

The invention is further described with reference to the following figures and examples:

a novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing system at least comprises: the system comprises a liquid nitrogen low-temperature storage tank 1, a liquid carbon dioxide storage tank 22, a supercharging device 5, a storage tank self-supercharging device, an air diffusing and heating device, a gasification device 8, a voltage-stabilizing and current-stabilizing device 15, an electric heating auxiliary heating device 12 and a metering device 19; the bottom of the liquid nitrogen low-temperature storage tank 1 is communicated with a liquid outlet pipe orifice 2 of the liquid nitrogen storage tank and then divided into two paths, one path is connected with a gas phase space at the top of the liquid nitrogen low-temperature storage tank 1 through a storage tank self-pressurization device to increase the pressure of the liquid nitrogen low-temperature storage tank 1, the other path is connected with a pressurization device 5 through a low-pressure liquid nitrogen pipeline 4, the pressurization device 5 is connected with a gas return port at the top of the liquid nitrogen low-temperature storage tank 1 through a gas return pipeline 6, the top of the liquid nitrogen low-temperature storage tank 1 is provided with an air dissipation heating device, a liquid carbon dioxide storage tank 22 is connected with the pressurization device 5 through a carbon dioxide liquid outlet pipeline 23, the pressurization device 5 is connected with a gasification device 8 through a high-pressure pipeline 7, the gasification device 8 is connected with an electric heating auxiliary heating device 12 through a gasification device gas outlet pipeline 9, the electric heating auxiliary heating device 12 is connected with a voltage stabilizing and current stabilizing device 15 through an auxiliary heating device gas outlet pipeline 14, and current stabilizing device 15 is connected with a user main pipe 21 through a voltage stabilizing and current stabilizing device gas stabilizing pipeline 16, the outlet pipeline 16 of the pressure stabilizing and flow stabilizing device is provided with a metering device 19.

The storage tank is from supercharging device contains from the pressure boost open valve 25, from pressure boost vaporizer 26, pressure regulator 27 and from pressure boost gas pipeline 28, liquid nitrogen storage tank goes out liquid outlet pipe 2's one way and is connected from pressure boost gas pipeline 28, is equipped with in proper order from the pressure boost on the pressure boost gas pipeline 28 and opens valve 25, from pressure boost vaporizer 26 and pressure regulator 27.

The heating device that diffuses to air contains gas discharge pipe orifice 35, gas-discharge valve 29, diffuse air inlet pipeline 30, diffuse heating device 31, diffuse air outlet pipeline 32, the thermoscope 33 and diffuse gas outlet 34, gas discharge pipe orifice 35 sets up at 1 top of liquid nitrogen low temperature storage tank, gas discharge pipe orifice 35 passes through gas discharge valve 29 and is connected with diffuse air inlet pipeline 30, diffuse air inlet pipeline 30's diffuse gas outlet 34 and external intercommunication, be equipped with diffuse heating device 31 on the diffuse air inlet pipeline 30 in proper order, diffuse air outlet pipeline 32 and thermoscope 33.

The gasification device gas outlet pipeline 9 is divided into two paths through a multi-path valve of the auxiliary heating device, one path is connected with the voltage and current stabilizing device 15 through an electric heating auxiliary heating device bypass pipeline 13, and the other path is connected with the voltage and current stabilizing device 15 after being connected with the electric heating auxiliary heating device 12 through an auxiliary heating device gas inlet pipeline 11.

The pressure and flow stabilizing device gas outlet pipeline 16 is divided into two paths through a metering device multi-path valve 17, one path is connected with a user main pipe 21 through a metering device bypass pipeline, and the other path is connected with the user main pipe 21 through a first cut-off valve 18A, a metering device 19 and a second cut-off valve 18B in sequence.

The supercharging device 5 is a liquid nitrogen pump.

The pressure and flow stabilizing device 15 is a pressure stabilizing tank.

A liquid nitrogen outlet pipe orifice valve is arranged on the liquid nitrogen storage tank liquid outlet pipe orifice 2; a carbon dioxide outlet valve 24 is arranged on the carbon dioxide outlet pipeline 23; the gasification device 8 is provided with a nitrogen purging device.

A novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing method adopts the fire prevention and extinguishing system and comprises the following steps:

when liquid nitrogen is needed to be used for fire prevention and extinguishment, liquid nitrogen in a liquid nitrogen low-temperature storage tank 1 is divided into two paths through a liquid outlet pipe orifice 2 of the liquid nitrogen storage tank, one path of liquid nitrogen enters a gas phase space at the top of the liquid nitrogen low-temperature storage tank 1 after being gasified and stabilized by a storage tank self-pressurization device, the pressure in the liquid nitrogen low-temperature storage tank 1 is increased, and normal transportation and distribution of the liquid nitrogen are ensured; the other path of liquid nitrogen flows to a supercharging device 5 through a low-pressure liquid nitrogen pipeline 4, the supercharging device 5 pressurizes the liquid nitrogen, the liquid nitrogen is pressurized to a set pressure and then enters a gasification device 8 through a high-pressure pipeline 7 to be gasified to form nitrogen, the pressure and the flow of the supercharging device 5 can be adjusted, a small amount of low-temperature gas can be generated by the supercharging device 5 in the operation process, and in order to ensure the pressure balance and reduce the fluctuation in the operation liquid nitrogen low-temperature storage tank 1, the low-temperature gas generated by the supercharging device 5 flows back to a gas return port at the top of the liquid nitrogen low-temperature storage tank 1 through a gas return pipeline 6; when the nitrogen does not need to be heated, the nitrogen enters the bypass pipeline 13 of the electric heating auxiliary heating device, is stabilized by the voltage stabilizing and current stabilizing device 15, passes through the air outlet pipeline 16 of the voltage stabilizing and current stabilizing device and is connected with the user main pipe 21; when the nitrogen needs to be heated, the nitrogen enters the auxiliary heating device air inlet pipeline 11 to be heated, and the heated nitrogen is stabilized by the pressure stabilizing and flow stabilizing device 15, then passes through the pressure stabilizing and flow stabilizing device air outlet pipeline 16 and then is connected with the user header pipe 21; when the nitrogen needs to be metered, the first cut-off valve 18A and the second cut-off valve 18B are opened, the nitrogen enters the metering device for metering, and the metered nitrogen enters the user header pipe 21; when the nitrogen does not need to be metered, the first cut-off valve 18A and the second cut-off valve 18B are closed, and the nitrogen enters a user header pipe 21 through a metering device bypass pipeline 20;

when liquid carbon dioxide is needed to be used for fire prevention and extinguishment, low-pressure nitrogen purging is carried out on the gasification device 8 through a nitrogen purging device, after purging, a carbon dioxide liquid outlet valve 24 is opened, liquid carbon dioxide in a liquid carbon dioxide storage tank 22 enters the supercharging device 5 through a carbon dioxide liquid outlet pipeline 23, the supercharging device 5 pressurizes liquid carbon dioxide, the liquid carbon dioxide is pressurized to a set pressure and then enters the gasification device 8 through the high-pressure pipeline 7 to be gasified to form a carbon dioxide gas source, the pressure and the flow of the supercharging device 5 can be adjusted, the carbon dioxide gas source enters the electric heating auxiliary heat device bypass pipeline 13 through the gasification device gas outlet pipeline 9, and after being stabilized by the pressure stabilizing and flow stabilizing device 15, the carbon dioxide gas source passes through the pressure stabilizing and flow stabilizing device gas outlet pipeline 16 and then is connected with the user header pipe 21; when the carbon dioxide gas source needs to be metered, the first cut-off valve 18A and the second cut-off valve 18B are opened, the carbon dioxide gas source enters the metering device for metering, and the metered carbon dioxide gas source enters the user main pipe 21; when the carbon dioxide gas source is not required to be metered, the first cut-off valve 18A and the second cut-off valve 18B are closed, and the carbon dioxide gas source enters a user main pipe 21 through a metering device bypass pipeline 20.

When the liquid nitrogen low-temperature storage tank 1 is used, the pressure in the liquid nitrogen low-temperature storage tank 1 is reduced, and in order to ensure normal transportation and distribution of liquid nitrogen, a storage tank self-pressurization device is adopted to pressurize the liquid nitrogen low-temperature storage tank 1; the tank self-pressurization device at least comprises: the system comprises a self-pressurization gasifier 26, a self-pressurization opening valve 25, a pressure regulator 27 and a pressurization gas pipeline 28, wherein liquid nitrogen in a liquid nitrogen low-temperature storage tank 1 is led out from a liquid outlet pipe orifice 2 of the liquid nitrogen storage tank and then is converted into nitrogen gas by the self-pressurization gasifier 26, the pressure of the nitrogen gas is regulated by the pressure regulator 27 to be stabilized at the same pressure as the internal pressure of the liquid nitrogen low-temperature storage tank 1, and then the nitrogen gas is sent back to a gas phase space at the top of the liquid nitrogen low-temperature storage tank 1 through the self-pressurization gas pipeline 28 to increase the pressure of the liquid nitrogen low-temperature storage tank 1;

the air diffusion heating device at least comprises a gas discharge pipe orifice 35, a gas discharge valve 29, a diffusion gas inlet pipeline 30, a diffusion heating device 31, a diffusion gas outlet pipeline 32, a temperature detector 33 and a diffusion gas outlet 34, when the pressure in the liquid nitrogen low-temperature storage tank 1 under the non-operation working condition is higher than the set pressure, the gas discharge valve 29 on the gas discharge pipe orifice 35 at the top of the liquid nitrogen low-temperature storage tank 1 is automatically opened, the low-temperature gas in the tank body is discharged to the diffusion heating device 31 to be heated, and then the low-temperature gas is discharged into an atmospheric system; when the pressure in the liquid nitrogen low-temperature storage tank 1 is lower than the set pressure, the gas discharge valve 29 on the storage tank is automatically closed; when the temperature detector 33 at the outlet of the diffusion heating means 31 shows a temperature lower than the ambient temperature by 5 c, the opening degree of the gas-discharge valve 29 is appropriately decreased.

The invention comprises a liquid nitrogen low-temperature storage tank 1, a liquid carbon dioxide storage tank 22, a supercharging device 5, a storage tank self-supercharging device (comprising a self-supercharging gasifier 26, a self-supercharging opening valve 25, a pressure regulator 27, a self-supercharging air pipeline 28 and the like), an air diffusing and heating device (comprising a gas discharge pipe orifice 35, a gas discharge valve 29, a diffusing air inlet pipeline 30, a diffusing and heating device 31, a diffusing air outlet pipeline 32, a temperature detector 33, a diffusing air outlet 34 and the like), a gasification device 8, a voltage stabilizing and current stabilizing device (pressure stabilizing tank) 15, an electric heating auxiliary heating device 12, a metering device 19, liquid nitrogen system power distribution equipment, liquid nitrogen system control equipment and the like, and auxiliary components such as pipelines, instruments, control valves, liquid level meters, pressure regulating devices and the like which are necessary for a system.

The liquid outlet pipe orifice 2 of the liquid nitrogen storage tank is connected to a supercharging device 5 through a low-pressure liquid nitrogen pipeline 4, namely a liquid nitrogen booster pump, in order to guarantee the pressure requirement of a user on a nitrogen source, the liquid nitrogen needs to be pressurized through the liquid nitrogen booster pump 5, and the liquid nitrogen is pressurized to a set pressure and then enters a gasification device 8 through a high-pressure pipeline 7 to be gasified. The pressure and flow of the pressure boosting device 5 can be adjusted. The pressurizing device 5 can generate a small amount of low-temperature gas in the operation process, and in order to ensure the pressure balance and reduce fluctuation in the operation liquid nitrogen low-temperature storage tank 1, the low-temperature gas generated by the pressurizing device 5 flows back to the gas return port at the top of the liquid nitrogen low-temperature storage tank 1 through the gas return pipeline 6.

In the use process of the liquid nitrogen low-temperature storage tank 1, the pressure in the tank can be reduced, and in order to ensure normal transportation and distribution of liquid nitrogen, a storage tank self-pressurization device is adopted to pressurize the liquid nitrogen low-temperature storage tank 1. The tank self-pressurization device at least comprises: the self-pressurization gasifier 26, the self-pressurization opening valve 25, the pressure regulator 27, the pressurization gas pipeline 28 and the like are adopted, liquid nitrogen is led out from the liquid outlet pipe orifice 2 of the liquid nitrogen storage tank, then the liquid nitrogen is gasified into a gaseous state by the self-pressurization gasifier 26, then the pressure of an outlet is stabilized at the same pressure as the internal pressure of the liquid nitrogen low-temperature storage tank 1 through the pressure regulation of the pressure regulator 27, and then the nitrogen is sent back to the gas phase space at the top of the liquid nitrogen low-temperature storage tank 1 through the self-pressurization gas pipeline 28, so that the pressure of the liquid nitrogen low-temperature storage tank 1 is increased. When the liquid nitrogen low-temperature storage tank 1 runs, the storage tank self-pressurization system is started when the pressure in the storage tank is lower than 50% of the rated pressure.

The liquid nitrogen low-temperature storage tank 1 and the liquid nitrogen in the pipeline are easy to cause personnel frostbite or freeze at a discharge port when being discharged, so that the diffused low-temperature liquid nitrogen needs to be heated and then discharged into the atmosphere, and 1 set of air diffusion heating device is designed for the system.

The pair of heat dissipation heating device includes at least: the liquid nitrogen low-temperature storage tank comprises a gas discharge pipe orifice 35, a gas discharge valve 29, a diffusing air inlet pipeline 30, a diffusing heating device 31, a diffusing air outlet pipeline 32, a temperature detector 33, a diffusing air outlet 34 and the like, and the liquid nitrogen low-temperature storage tank 1 is emptied from the gas discharge pipe orifice 35 to the air diffusing heating device. When the pressure in the liquid nitrogen low-temperature storage tank 1 under the non-operation working condition is higher than the set pressure, automatically opening a gas discharge valve 29 of the liquid nitrogen low-temperature storage tank 1, discharging the low-temperature gas in the tank body to a diffusion heating device 31 for heating, and then discharging the low-temperature gas into an atmospheric system; when the pressure in the liquid nitrogen low-temperature storage tank 1 is lower than the set pressure, the gas discharge valve 29 on the storage tank is automatically closed. When the temperature gauge 33 at the outlet of the diffusion heating unit 31 shows a temperature lower than the ambient temperature by 5 deg.C, the opening of the gas-discharge valve 29 of the unit is appropriately reduced.

In order to ensure the flow of nitrogen and carbon dioxide required by the user, liquid nitrogen and liquid carbon dioxide must be gasified. Liquid nitrogen and liquid carbon dioxide flow through the gasification device 8, and heat exchange is carried out through air convection to heat and gasify the liquid nitrogen at the temperature of-196 ℃ and the liquid carbon dioxide at the temperature of-17 ℃. The medium in the gasification device 8 is in a gas-liquid two-phase state, and liquid nitrogen and liquid carbon dioxide flow through the gas outlet pipeline 9 of the gasification device after being fully gasified in the device.

In order to meet the requirements of stability and safety of nitrogen and carbon dioxide sources of users and ensure that the gas flow rate is dynamically changed, the gas transmission pressure can be stabilized at the design pressure, and a set of 15 pressure-stabilizing and flow-stabilizing devices is also designed for the system.

In consideration of the use requirement of cold regions, in order to ensure the gasification effect of liquid nitrogen and the safety and reliability of pipelines used after gasification, the nitrogen gasified by the gasification device 8 needs to be subjected to auxiliary heating, and the system is provided with an electric heating auxiliary heating device 12.

The temperature of the nitrogen at the outlet of the gasification device 8 is usually lower than the ambient temperature by about 10 ℃, when the ambient temperature is lower than minus 10 ℃, pipelines from the gasification device 8 to the electric heating auxiliary heating device 12 are easy to frost, and at the moment, the electric heating auxiliary heating device 12 is started to heat the nitrogen continuously; if the pipelines from the gasification device 8 to the electric heating auxiliary heating device 12 are free from frosting or the temperature is higher than minus 10 ℃, the electric heating auxiliary heating device 12 is not required to be started, nitrogen is directly conveyed to the voltage-stabilizing and current-stabilizing device 15 through the electric heating auxiliary heating device bypass pipeline 13, and the whole process can realize automatic interlocking operation.

In order to account for the production cost, a set of metering devices (flow meters) 19 is arranged on the air outlet pipeline 16 of the pressure stabilizing and flow stabilizing device. The metering device 19 is arranged on the air outlet pipeline 16 of the pressure stabilizing and flow stabilizing device, a bypass pipeline 20 of the metering device is additionally designed, a first cut-off valve 18A and a second cut-off valve 18B are respectively arranged on the pipelines of the inlet metering device and the outlet metering device, and the reading of the metering device 19 can be remotely transmitted to a central control room.

The liquid carbon dioxide storage tank 22 enters the pressurization device 5 through the carbon dioxide liquid outlet pipeline 23, the pressure and flow requirements of a user on an air source can be guaranteed through pressurization, and the pressurized liquid carbon dioxide enters the gasification device 8 through the high-pressure pipeline 7 for gasification. When the carbon dioxide gasification system is used up and needs to be switched to a liquid nitrogen gasification system, the gasification device 8 needs to be purged by low-pressure nitrogen, and at the moment, the storage tank self-pressurization system needs to be started, and a valve on a purging pipeline needs to be opened.

The invention relates to a technological process of a fire prevention and extinguishing system, which is simply described as follows:

liquid nitrogen low-temperature storage tank → liquid nitrogen pressurization → gasification system → user

Liquid outlet of liquid nitrogen low-temperature storage tank → storage tank supercharging device → liquid nitrogen low-temperature storage tank

Safety valve and evacuation valve drain → air-diffusing heating device → discharge to atmosphere

Liquid carbon dioxide storage tank → pressurization → gasification system → user

The above embodiments are only specific cases of the present invention, and the protection scope of the present invention includes but is not limited to the product forms and styles of the above embodiments, and any changes or modifications of the novel liquid nitrogen and liquid carbon dioxide fire prevention and extinguishing system and method according to the claims of the present invention and those skilled in the art should fall into the protection scope of the present invention.