Gas explosion simulation experiment device in goaf spontaneous ignition environment

Abstract

The utility model discloses a gas explosion simulation experiment device in a goaf spontaneous ignition environment, and belongs to the technical field of coal mine goaf gas explosion disaster prevention and control. Comprising a goaf coal spontaneous combustion simulation system and a gas explosion simulation system. The goaf coal spontaneous combustion simulation system comprises a gas cylinder, a temperature programming box, a gas chromatograph and a computer; the gas explosion simulation system comprises a spherical explosion device, a cavity heating and temperature control device, a gas distribution device, a vacuum pump, a control box and an ignition energy generator; the computer is connected with the control box; according to the utility model, the goaf coal spontaneous combustion experimental device and the gas explosion experimental device are linked and combined to form an integrated experimental platform, so that the problem that the gas explosion characteristic is unclear under the synergistic effect of the temperature of a goaf spontaneous combustion environment and multi-element gas is solved.

Description

Technical Field

[0001] This utility model belongs to the field of coal mine goaf gas explosion disaster prevention technology, specifically a gas explosion simulation experimental device under the natural ignition environment of a goaf. Background Technology

[0002] Coal within goaf areas is prone to spontaneous combustion, generating significant heat that raises the ambient temperature and creates a dynamically changing temperature field. The resulting combustion produces combustible gases such as CO, which mix with methane gas to form a gas mixture. This mixture is distributed at varying concentrations throughout the goaf, and the dynamic flow of this mixed gas is influenced by air leakage and fire pressure. Since the spontaneous combustion of residual coal in the goaf is a gradual heating process, a gas explosion is induced when the high-temperature ignition source is sufficient to detonate the methane gas and the gas concentration is just within the explosive limit. This gas explosion induced by the spontaneous combustion of residual coal in the goaf has two distinct characteristics: a high ambient temperature at the time of ignition and a multi-component gas mixture. Both ambient temperature and gas composition significantly influence gas explosions, and the gas composition in the goaf changes continuously with increasing temperature during the spontaneous combustion process. Therefore, the gas explosion induced by the spontaneous combustion of residual coal in the goaf is influenced by the synergistic effect of temperature and the multi-component gas mixture, and is constantly in a dynamic process. Currently, the characteristics of gas explosion in goaf areas under the conditions of coal auto-ignition temperature and the synergistic effect of multiple gases are still unclear. Therefore, a device is needed to determine the gas explosion limits under spontaneous combustion conditions in goaf areas. Utility Model Content

[0003] This invention overcomes the shortcomings of existing technologies and proposes a gas explosion simulation experimental device under the spontaneous combustion environment of a goaf; it solves the problem of unclear gas explosion characteristics under the combined effects of temperature and multiple gases in the spontaneous combustion environment of a goaf.

[0004] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0005] An experimental device for simulating gas explosion under spontaneous combustion in a goaf environment includes a goaf coal spontaneous combustion simulation system and a gas explosion simulation system.

[0006] The coal spontaneous combustion simulation system for goaf areas includes gas cylinders, a programmed temperature rise chamber, a gas chromatograph, and a computer. A coal sample container is installed on the bottom surface of the programmed temperature rise chamber, and a coal sample is placed inside the container. A thermocouple is connected to the coal sample container and inserted into the coal sample. An outlet is located at the top of the coal sample container. The outlet is connected to the gas chromatograph via an inlet pipe, and the gas chromatograph is connected to the computer. A heater is installed inside the programmed temperature rise chamber.

[0007] The gas explosion simulation system includes a spherical explosion device, a cavity heating and temperature control device, a gas distribution device, a vacuum pump, a control box, and an ignition energy generator. An ignition electrode is connected inside the spherical explosion device. The ignition energy generator is connected to the ignition electrode. The spherical explosion device is connected to the cavity heating and temperature control device, and a second air inlet is located at the bottom of the spherical explosion device, which is connected to the gas distribution device. A nozzle is located at the bottom inside the spherical explosion device, and the nozzle is connected to the second air inlet. The spherical explosion device is connected to the vacuum pump, and a temperature sensor and a pressure sensor are connected to it. The temperature sensor, pressure sensor, ignition energy generator, cavity heating and temperature control device, and gas distribution device are all connected to the control box. A computer is connected to the control box.

[0008] Furthermore, a fan is installed on the top surface inside the programmable temperature chamber; the heater is located below the fan.

[0009] Furthermore, the temperature control and data acquisition system is installed inside the programmable heating chamber, and a control panel is connected to the front end of the temperature control and data acquisition system.

[0010] Furthermore, the chamber of the programmed heating chamber is equipped with a gas preheating copper pipe; the bottom of the coal sample container is equipped with a first air inlet, which is connected to one end of the gas preheating copper pipe through a gas pipe, and the other end of the gas preheating copper pipe is connected to a gas cylinder through a gas pipe.

[0011] Furthermore, the outer wall of the spherical explosive device is equipped with a cavity heating blanket, and the cavity heating and temperature control device is connected to the cavity heating blanket.

[0012] Furthermore, the spherical explosive device is a 20L spherical explosive device.

[0013] The beneficial effects of this utility model compared to the prior art are as follows:

[0014] This invention integrates a coal spontaneous combustion experimental device and a gas explosion experimental device in a goaf to form an integrated experimental platform, solving the problem of unclear gas explosion characteristics under the temperature and multi-gas synergistic effect in a goaf spontaneous combustion environment. By using coal spontaneous combustion experiments to obtain the gaseous products and their contents at different temperature points, a direct link between different temperature points and gaseous products is established. The data is transmitted to a control console via a computer, which controls the chamber heating and temperature control device and the high-precision automatic gas distribution device to modulate the temperature and multi-gas mixture required for gas explosion within a 20L spherical explosion device, creating a gas explosion environment and realizing a gas explosion experiment under a goaf spontaneous combustion environment.

[0015] This invention can establish a direct link between the temperature and gaseous products during the spontaneous combustion process in goaf areas. By using a cavity heating and temperature control device, a high-density automatic gas distribution device, and a 20L spherical explosion device, it can conduct gas explosion experiments in a multi-component mixed gas environment at different temperature points, and obtain scientific and effective gas explosion characteristic parameters, which can effectively prevent gas explosion accidents in goaf areas. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the gas explosion simulation experimental device under the spontaneous combustion environment of the goaf described in this utility model;

[0017] Figure label:

[0018] 1. Gas cylinder; 2. Gas preheating copper pipe; 3. First gas inlet; 4. Coal sample; 5. Coal sample container; 6. Fan; 7. Heater; 8. Gas outlet; 9. Thermocouple; 10. Asbestos insulation layer; 11. Control panel; 12. Programmed temperature chamber; 13. Gas chromatograph; 14. Computer; 15. Control box; 16. Ignition energy generator; 17. Gas distribution device; 18. Ignition electrode; 19. Temperature sensor; 20. Pressure sensor; 21. 20L spherical explosive device; 22. Second gas inlet; 23. Nozzle; 24. Chamber heating blanket; 25. Vacuum pump; 26. Chamber heating and temperature control device. Detailed Implementation

[0019] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, this utility model will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit it. The technical solution of this utility model will be described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0020] See Figure 1 This embodiment proposes a gas explosion simulation experimental device under the spontaneous combustion environment of a goaf, including a goaf coal spontaneous combustion simulation system and a gas explosion simulation system.

[0021] The coal spontaneous combustion simulation system in the goaf mainly consists of a gas cylinder 1, a programmed temperature rise chamber 12, and a gas chromatograph 13. The programmed temperature rise chamber 12 mainly comprises a gas preheating copper pipe 2, a heater 7, a thermocouple 9, a coal sample container 5, and a temperature control and data acquisition system. Specifically, the programmed temperature rise chamber 12 has a stainless steel inner liner with an outer asbestos insulation layer 10, and can perform programmed temperature rise at a predetermined rate under the control of the temperature control system. A coal sample container 5 is installed on the bottom surface inside the chamber of the programmed heating chamber 12, and a coal sample 4 is placed inside the coal sample container 5. A thermocouple 9 is connected to the coal sample container 5 and inserted into the coal sample 4. A first air inlet 3 is provided at the bottom of the coal sample container 5. The first air inlet 3 is connected to one end of a gas preheating copper pipe 2 through a gas pipe. The other end of the gas preheating copper pipe 2 is connected to a gas cylinder 1 through a gas pipe. An air outlet 8 is provided at the top of the coal sample container 5. A fan 6 is provided on the top surface inside the chamber. The function of the fan 6 is to circulate the gas in the chamber and ensure uniform temperature distribution in the chamber. A heater 7 is provided below the fan 6. A temperature control and data acquisition system is provided on the other side of the chamber. A control panel 11 is connected to the front end of the temperature control and data acquisition system. The temperature control and data acquisition system is an existing device component used to electrically connect to the heater 7, so that the programmed heating chamber 12 can perform programmed heating at a certain heating rate under the action of the temperature control and data acquisition system. In this embodiment, the temperature control and data acquisition system adopts a Greda GHG programmed heating system. The gas outlet 8 is connected to the gas chromatograph 13 via the gas inlet pipe, and the gas chromatograph 13 is connected to the computer 14.

[0022] After the coal-oxygen reaction gas supplied by gas cylinder 1 enters the programmed temperature rise chamber 12, it is first fully preheated by the gas preheating copper pipe 2, and then enters the coal sample tank 5 from the first gas inlet 3 below the coal sample tank 5. Under different temperature conditions, it reacts with the coal sample 4 to produce coal-oxygen. The generated gas products enter the gas chromatograph 13 from the gas outlet 8 above the coal sample tank 5. The gas chromatograph 13 analyzes the gas products and their contents, and transmits the parameters such as the gas products and their concentrations at different temperature points during the coal spontaneous combustion process to the computer 14, providing accurate gas ratio data for the gas explosion simulation system under the multi-element mixed gas environment at different temperatures.

[0023] The gas explosion simulation system mainly consists of a 20L spherical explosion device 21, a cavity heating and temperature control device 26, a gas distribution device 17, a vacuum pump 25, a control box 15, and an ignition energy generator 16.

[0024] An ignition electrode 18 is connected inside the 20L spherical explosive device 21; an ignition energy generator 16 is connected to the ignition electrode 18; a cavity heating blanket 24 is provided on the outer wall of the 20L spherical explosive device 21, and a cavity heating and temperature control device 26 is connected to the cavity heating blanket 24 to adjust the heating temperature of the cavity heating blanket 24, thereby heating the internal cavity of the 20L spherical explosive device 21; a second air inlet 22 is provided at the bottom of the 20L spherical explosive device 21, and the second air inlet 22 is connected to the gas distribution device 1. The 20L spherical explosive device 21 is connected to a 7-phase connection; a nozzle 23 is installed at the lower part of the interior, and the nozzle 23 is connected to the second air inlet 22; the 20L spherical explosive device 21 is connected to a vacuum pump 25, which evacuates the interior of the 20L spherical explosive device 21; the 20L spherical explosive device 21 is connected to a temperature sensor 19 and a pressure sensor 20; the temperature sensor 19, pressure sensor 20, ignition energy generator 16, cavity heating and temperature control device 26, and gas distribution device 17 are all connected to the control box 15. The computer 14 is connected to the control box 15.

[0025] The accurate gas ratio data of the multi-component mixed gas environment at different temperatures obtained from the goaf coal spontaneous combustion simulation system are processed by computer 14 and transmitted to control box 15. Control box 15 adjusts the gas composition output by gas distribution device 17 according to the data. In high-precision automatic mode, gas distribution device 17 achieves high-precision distribution of multi-component mixed gas according to the gas product content ratio data, forming multi-component mixed gas at different temperatures. It is sent to 20L spherical explosion device 21 through second air inlet 22 and sprayed out by nozzle 23, evenly distributed in the explosion chamber. At the same time, the chamber heating and temperature control device 26 is controlled according to the temperature data. After receiving the data, the chamber heating and temperature control device 26 uses chamber heating blanket 24 to evenly heat and control the temperature of 20L spherical explosion device 21.

[0026] After the control box 15 creates the temperature environment and multi-component mixed gas environment required for gas explosion in the 20L spherical explosion device 21, it inputs a signal to the ignition energy generator 16. The ignition electrode 18 is used to ignite the gas in the 20L spherical explosion device 21 to achieve the purpose of gas explosion. The temperature and pressure changes in the 20L spherical explosion device 21 are monitored by the temperature sensor 19 and the pressure sensor 20 to determine the gas explosion characteristics and obtain the gas explosion limit under the spontaneous combustion environment of the goaf.

[0027] It should be noted that the temperature sensor 19, pressure sensor 20, ignition energy generator 16, cavity heating and temperature control device 26, gas distribution device 17, and control box 15 used in this embodiment are all existing devices. The ignition energy generator 16 is model BWGD-05; the cavity heating and temperature control device 26 is model KLKTS011; the gas distribution device 17 is a dynamic gas distribution instrument SSGM; and the control box 15 is a PLC electrical control cabinet. The control programs for other components through the control box 15 are all existing conventional programs, and this utility model has not made any improvements in the control steps.

[0028] The specific experimental procedure is as follows: Dry air in air storage tank 1 is fully preheated by gas preheating copper pipe 2 before the experiment, and then enters coal sample tank 5 through the first air inlet 3 to react with the pre-prepared coal sample 4. The gaseous products generated by the reaction flow out of coal sample tank 5 through air outlet 8, and the gaseous products of the coal-oxygen reaction are analyzed by gas chromatograph 13. During the reaction, thermocouple 9 monitors and controls the reaction temperature in coal sample tank 5, and transmits the data to control panel 11. Control panel 11 controls fan 6 and heater 7 above programmable temperature rise chamber 12. Heater 7 controls the temperature inside programmable temperature rise chamber 12, and fan 6 ensures uniform temperature distribution inside programmable temperature rise chamber 12, so that programmable temperature rise chamber 12 is programmed to rise at a certain heating rate under the temperature control system. The control panel 11 displays the coal spontaneous combustion reaction temperature points and transmits the gas products and contents corresponding to each temperature point obtained by the gas chromatograph 13 to the computer 14. The computer 14 is linked with the control box 15 in the gas explosion experimental device, and can transmit the data of different temperature points and their corresponding gas products and contents during the coal spontaneous combustion process to the control box 15. The control box 15, after identification and processing, transmits the data to the cavity heating and temperature control device 26 and the gas distribution device 17 respectively. Before the gas explosion experiment, the specific pressure value needs to be set according to the vacuum level required by the experiment. The vacuum pump 25 evacuates the 20L spherical explosion device 21. The cavity heating and temperature control device 26 heats the 20L spherical explosion device 21 evenly to different temperature points through the cavity heating blanket 24. The high-precision automatic gas distribution device 17 distributes the multi-component mixed gas corresponding to different temperature points. The gas enters through the air inlet below the 20L spherical explosion device 21 and is evenly distributed in the 20L spherical explosion device 21 through the nozzle 23. Thus, the environmental conditions of the gas explosion induced by the spontaneous combustion of coal in the goaf are restored in the 20L spherical explosion device 21. The control box 15 transmits the signal to the ignition energy generator 16. The ignition electrode 18 discharges to generate a spark gap to ignite the experimental gas. A 20L spherical explosion device 21 is connected to a temperature sensor 19 and a pressure sensor 20. The monitoring data from both sensors is transmitted to a control box 15 to directly monitor temperature and pressure changes within the 20L spherical explosion chamber. Parameters such as gas explosion limits, explosion pressure, and maximum pressure rise rate are analyzed to determine the gas explosion boundaries under different coal spontaneous combustion environments in goaf areas. This embodiment also proposes a method for using a gas explosion simulation experimental device under spontaneous combustion conditions in goaf areas, including the following steps:

[0029] Step 1: Take a fresh coal sample from the working face, process and screen out 800g of coal sample particles of 10~20mm, put them into coal sample container 5, and set the initial temperature of the programmable heating chamber 12.

[0030] Step 2: Using dry air as the gas source, air is introduced before the experiment to purge impurities and adsorbed gases from the coal sample container 5. A suitable programmed heating rate and termination temperature are set, and the mixed gas products at the upper outlet of the coal sample container 5 are analyzed at regular intervals using a gas chromatograph 13 to obtain the gas products and their contents at different temperature points.

[0031] Step 3: First, use vacuum pump 25 to set the vacuum level and the corresponding pressure value according to the experimental requirements to evacuate the cavity of the 20L spherical explosion device 21.

[0032] Step 4: Based on the gas products and contents obtained from the coal spontaneous combustion experiment at different temperature points, the data is analyzed, processed, and transmitted to the control box 15 for the gas explosion experiment. This data is then transmitted to the cavity heating and temperature control device 26 and the gas distribution device 17. The 20L spherical explosion device 21 is heated by the cavity heating blanket 24 to create a coal spontaneous combustion temperature environment in the goaf. The gas distribution device 17 creates a multi-component mixed gas environment containing CH4, CO, C2H4, C2H6, C2H2, N2, and CO2 at different temperature points. After the temperature environment and the multi-component mixed gas environment are formed, the control box 15 transmits a signal to the ignition energy generator 16. The ignition electrode 18 ignites the gas inside the explosion cavity, achieving a gas explosion.

[0033] Step 5: Through gas explosion experiments, the explosion characteristics such as the gas explosion limit, maximum explosion pressure, and maximum pressure rise rate under the influence of a single gas (combustible and inert) and a multi-gas (combustible and inert) are obtained, clarifying the influence of spontaneous combustion gas products of coal in the goaf on gas explosion.

[0034] Step 6: Conduct gas explosion experiments under the combined effects of coal spontaneous combustion temperature and multiple gases in the goaf to obtain the gas explosion limits, maximum explosion pressure, and maximum pressure rise rate at different stages of coal spontaneous combustion. Understand the gas explosion characteristics under the combined effects of coal spontaneous combustion temperature and multiple gases in the goaf and determine the gas explosion limits under the spontaneous combustion environment of the goaf.

[0035] The above description is a further detailed explanation of the present invention in conjunction with specific preferred embodiments. It should not be considered that the specific embodiments of the present invention are limited to this. For those skilled in the art, several simple deductions or substitutions can be made without departing from the present invention, and all such deductions or substitutions should be considered to fall within the scope of patent protection determined by the submitted claims.

Claims

1. A gas explosion simulation experiment device in a goaf spontaneous combustion environment, characterized in that, The goaf coal spontaneous combustion simulation system and the gas explosion simulation system are included. The goaf coal spontaneous combustion simulation system comprises a gas cylinder (1), a programmed temperature box (12), a gas chromatograph (13) and a computer (14); a coal sample jar (5) is arranged on the bottom surface of the inside of the box body of the programmed temperature box (12), and a coal sample (4) is arranged in the coal sample jar (5); the coal sample jar (5) is connected with a thermocouple (9), and the thermocouple (9) is inserted into the coal sample (4); an air outlet (8) is arranged on the top of the coal sample jar (5); the air outlet (8) is connected with the gas chromatograph (13) through an air inlet pipe, and the gas chromatograph (13) is connected with the computer (14); a heater (7) is arranged in the programmed temperature box (12). The gas explosion simulation system comprises a spherical explosion device, a cavity heating and temperature control device (26), a gas distribution device (17), a vacuum pump (25), a control box (15) and an ignition energy generator (16); the spherical explosion device is connected with an ignition electrode (18); the ignition energy generator (16) is connected with the ignition electrode (18); the spherical explosion device is connected with the cavity heating and temperature control device (26), the bottom of the spherical explosion device is provided with a second air inlet (22), and the second air inlet (22) is connected with the gas distribution device (17); a nozzle (23) is arranged below the inside of the spherical explosion device, and the nozzle (23) is connected with the second air inlet (22); the spherical explosion device is connected with the vacuum pump (25), and the spherical explosion device is connected with a temperature sensor (19) and a pressure sensor (20); the temperature sensor (19), the pressure sensor (20), the ignition energy generator (16), the cavity heating and temperature control device (26) and the gas distribution device (17) are all connected with the control box (15); the computer (14) is connected with the control box (15).

2. The gas explosion simulation experiment device in a goaf spontaneous combustion environment according to claim 1, characterized in that, A fan (6) is arranged on the top surface of the inside of the box body of the programmed temperature box (12); and the heater (7) is located below the fan (6).

3. The gas explosion simulation experiment device in a goaf spontaneous combustion environment according to claim 1, characterized in that, A temperature control and data acquisition system is arranged in the box body of the programmed temperature box (12), and a control panel (11) is connected to the front end of the temperature control and data acquisition system.

4. The gas explosion simulation experimental device in a goaf spontaneous combustion environment according to claim 1, characterized in that, A gas preheating copper pipe (2) is arranged in the box body of the programmed temperature box (12); a first air inlet (3) is arranged at the bottom of the coal sample jar (5), the first air inlet (3) is connected with one end of the gas preheating copper pipe (2) through an air pipe, and the other end of the gas preheating copper pipe (2) is connected with the gas cylinder (1) through an air pipe.

5. The gas explosion simulation experimental device in a goaf spontaneous combustion environment according to claim 1, characterized in that, A cavity heating blanket (24) is arranged on the outer wall of the spherical explosion device, and the cavity heating and temperature control device (26) is connected with the cavity heating blanket (24).

6. The gas explosion simulation experimental device in a goaf spontaneous combustion environment according to claim 1, characterized in that, The spherical explosion device is a 20L spherical explosion device (21).

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