WO2019072183A1

WO2019072183A1 - Coal seam secondary anti-reflection device and method by means of joint efforts of thermal disturbance and drilling gas explosion

Info

Publication number: WO2019072183A1
Application number: PCT/CN2018/109565
Authority: WO
Inventors: 倪冠华; 解宏超; 程卫民; 李钊; 谢景娜; 董凯
Original assignee: 山东科技大学
Priority date: 2017-10-11
Filing date: 2018-10-10
Publication date: 2019-04-18
Also published as: CN107701163B; CN107701163A

Abstract

A coal seam secondary anti-reflection device by means of joint efforts of thermal disturbance and drilling gas explosion, comprising a microwave radiation system, a drilling gas detonation system, a gas injecting fire preventing and fighting system, and a gas extraction device (8). The microwave radiation system consists of a microwave radiation generator (10), a waveguide tube valve (11), a waveguide tube (12), and a microwave radiation probe (13); the drilling gas detonation system consists of a drilling gas detonation monitoring device (15), a pulse ignition head (16), a gas concentration sensor (17), and a temperature sensor (18); the gas injecting fire preventing and fighting system consists of a heptafluoropropane gas injection pipe (6), and an air injection pipe valve (7); a front end of a casing pipe (4) penetrates into a borehole (2), and a rear end of the casing pipe is connected to the microwave radiation generator; the upper end of the casing pipe extending out of the borehole is connected to the gas extraction device and the heptafluoropropane gas injecting pipe, and the lower end of the casing pipe extending out of the borehole is connected to the drilling gas detonation monitoring device (15); the microwave radiation probe and the pulse ignition head penetrate into the borehole along with the casing pipe; a sensor transmits the gas concentration and the temperature situation in the casing pipe in real time to the gas detonation monitoring device by means of an M12 connector (19). Also disclosed is a coal seam secondary anti-reflection method by means of joint efforts of thermal disturbance and drilling gas explosion.

Description

Coal seam secondary anti-reflection device and method for thermal disturbance and borehole gas explosion cooperation

Technical field

The invention relates to a coal seam secondary anti-reflection device and method for thermal disturbance and borehole gas explosion cooperation, and belongs to the field of coal seam anti-reflection gas drainage in coal mine underground area, and is especially suitable for high adsorption and difficult desorption gas coal seam operation.

Background technique

There are some gas coal seams with high adsorption and difficult desorption characteristics in China's coal seams. With the increase of deep mining and the promotion of high-efficiency intensive production, the extraction efficiency is low and the drilling construction volume is large. The problem can no longer meet the current needs of gas disaster prevention. How to promote the desorption of coal seam gas and improve the gas drainage effect is a hotspot of foreign research in recent years. The main measures are: hydraulic cutting, hydraulic cutting, deep hole pre-cracking. Blasting, mining protective layer, etc., hydraulic cutting seams have difficulty in cutting hard coal, limited range of soft coal slitting pressure relief, hydraulic grooving is easy to deteriorate the working environment; deep hole pre-cracking blasting is easy to produce dumb guns and leave a safety hazard. The single promotion of gas desorption technology faces many limitations, so there is an urgent need for an efficient, composite technology to meet the problems that need to be addressed.

Summary of the invention

Technical Problem: The object of the present invention is to provide a secondary anti-reflection device and method for coal seams in thermal disturbance and borehole gas explosion in view of the problems existing in the existing high-adsorption, hard-desorbable gas coal seam promoting gas desorption technology. Make up for the limitations of the existing single coal seam to promote gas desorption technology, increase the permeability of coal seams, and accelerate the secondary desorption of coal seam gas, so as to achieve high efficiency of coal seam gas drainage.

Technical solution: a thermal perturbation and borehole gas explosion cooperative coal seam secondary anti-reflection device of the present invention, comprising a microwave radiation system, a borehole gas detonation system, a gas injection fire prevention system and a gas extraction device; the microwave radiation The system is composed of a microwave radiation generator, a waveguide valve, a waveguide, and a microwave radiation probe. The microwave radiation probe is externally provided with a protection screen tube 2. The drilling gas detonation system is composed of a drilling gas detonation monitoring device and a pulse ignition head. The gas concentration control system is composed of a heptafluoropropane gas injection pipe and a gas injection pipe valve. The front end of the casing penetrates into the borehole, and the rear end is connected with a microwave generator. The gas extraction device and the heptafluoropropane gas injection pipe are connected with a drilling gas detonation monitoring device at the lower end, the microwave radiation probe and the pulse ignition head penetrate into the borehole with the casing, and the gas concentration sensor and the temperature sensor transmit the gas in the casing through the M12 connector in real time. Concentration and temperature conditions to the gas detonation monitoring device.

The thermal perturbation and the gas-fired explosion of the present invention cooperate with the coal seam secondary anti-reflection method, comprising the following steps:

a drilling and drilling holes in the coal seam to be extracted, the inner diameter of the drill hole being larger than the outer diameter of the casing by 1 to 2 mm;

b. Feed the front end of the casing with the microwave radiation probe and the pulse ignition head into the borehole, and fix it with the sealing material; the front end of the casing is arranged to protect the coal seam, and the rear end of the casing is connected. a microwave radiation generator, the upper end of the casing extending from the borehole is connected with the gas extraction device and the heptafluoropropane gas injection pipe, and the lower end of the casing extending from the drill hole is connected with the drilling gas detonation monitoring device;

c. Turn on the microwave radiation generator, perform microwave radiation on the coal seam, heat the coal seam and generate crack holes in the coal seam, promote gas desorption, and conduct gas drainage through the gas extraction device;

d. When the gas leakage monitoring device monitors that the gas concentration is 5%-9%, 10%-16%, the ignition of the ignition head is controlled, the gas in the borehole is detonated, the coal seam is shattered, and the coal seam gas is promoted twice. Desorption

e. When the temperature is higher than the threshold of 280 ° C, heptafluoropropane is injected through a heptafluoropropane gas injection pipe to cool the fire.

f. Repeat steps c, d, and e to realize the secondary anti-drainage process of coal seam in thermal disturbance and borehole gas explosion.

The high-strength protection screen tube outside the microwave radiation probe can prevent damage to the microwave radiation probe for various reasons, and the protection screen tube does not affect the microwave radiation.

The temperature threshold is 280 ° C. When the threshold is exceeded, the monitoring system issues an alarm, and the gas injection and fire suppression system responds, injecting heptafluoropropane to extinguish the fire and prevent coal and gas from spontaneous combustion.

The detonation gas concentration is 5%-9%, 10%-16% in order to manufacture a small-scale gas explosion, and avoid the potential danger of high-intensity explosion of gas.

Advantageous Effects: The present invention solves the limitation of the existing high-adsorption, hard-desorbable gas coal seam promoting coal seam gas technology, and adopts a combination of microwave and induced gas explosion in the borehole to first perform microwave irradiation on the coal seam to heat the coal seam. And crack holes are generated in the coal seam to promote gas desorption. When the gas concentration reaches 5%-9% and 10%-16% of the gas explosion concentration, the pulse ignition device ignites, detonates the gas in the borehole, and shatters the coal seam. Promote the secondary desorption of coal seam gas, and then discharge the gas through the gas extraction device to achieve the effect of pre-extracting coal seam gas.

DRAWINGS

Figure 1 is a schematic view of an embodiment of the present invention

Figure 2 is a schematic view of the structure of the present invention

In the picture: 1-coal, 2-hole, 3-protected screen one, 4-casing, 5-sealing material, 6-heptafluoropropane gas injection pipe, 7-injection pipe valve, 8-gas extraction device, 9 - Gas extraction valve, 10- microwave radiation generator, 11-wave tube valve, 12-wave tube, 13-microwave radiation probe, 14-protected screen tube 2, 15-gas detonation monitoring device, 16-pulse ignition head , 17-gas concentration sensor, 18-temperature sensor, 19-M12 connector

The embodiments of the present invention are further described below with reference to the accompanying drawings:

In Fig. 1, a thermal perturbation and borehole gas explosion cooperation coal seam secondary anti-reflection device comprises a microwave radiation generator 10, a waveguide valve 11, a waveguide 12, a microwave radiation probe 13, a probe protection screen tube 14 The microwave radiation system comprises a borehole gas detonation system consisting of a borehole gas detonation monitoring device 15, a pulse ignition head 16, a gas concentration sensor 17, and a temperature sensor 18, and a gas injection composed of a heptafluoropropane gas injection pipe 6 and a gas injection pipe valve 7. Fire prevention system, gas extraction device 8. The front end of the sleeve 4 penetrates into the borehole 2, the rear end of the sleeve 4 is connected with the microwave generator 10, and the sleeve 4 extending from the borehole 2 is terminated with a gas extraction device 8, a heptafluoropropane gas injection pipe 6, and a drill at the lower end. The Kongvas detonates the monitoring device 15. The microwave radiation probe 13 and the pulse ignition head 16 penetrate into the borehole 2 with the casing 4, and the gas concentration sensor 17 and the temperature sensor 18 transmit the gas concentration and temperature in the casing 4 through the M12 connector 19 to the gas detonation monitoring device 15 in real time. .

The method for cooperating a gas permeation with a borehole gas explosion in a coal seam secondary penetration method comprises the steps of: drilling a drilling hole 2 in a gas seam to be extracted, the inner diameter of the borehole 2 being smaller than the casing 4 The diameter of the casing is 1 to 2 mm; the front end of the casing 4 in which the microwave radiation probe 13 and the pulse ignition head 16 are placed is deep into the borehole 2, and is sealed with a sealing material 5; a high-strength protective screen is arranged at the front end of the casing 4. a third, used to support the coal seam 1, the upper end of the casing 4 extending out of the borehole 2 is connected to the gas extraction device 8, the heptafluoropropane gas injection pipe 6, the lower end is connected to the borehole gas detonation monitoring device 15; the microwave radiation generator 10 is turned on, The coal seam 1 is subjected to microwave radiation, the coal seam 1 is heated and a crack hole is generated in the coal seam 1, the gas desorption is promoted, and the gas is extracted by the gas extraction device 8; when the gas emission detonation monitoring device 15 monitors the gas concentration is 5 When %-9%, 10%-16%, the ignition pulse ignition head 16 is ignited, the gas in the borehole 2 is detonated, the coal seam 1 is shattered, and the second desorption of the coal seam 1 watt is promoted; when the temperature is detected to exceed the threshold value 280 At °C, heptafluoropropane is injected to cool down the fire; Step c, d, e, and cooperate to achieve thermal disturbance explosion of the secondary borehole gas coal extraction process AR.

The high-strength protection screen tube 14 outside the microwave radiation probe 13 can prevent the microwave radiation probe 13 from being damaged for various reasons, and the protection screen tube 14 does not affect the microwave radiation.

The temperature threshold is 280 ° C. When the temperature threshold is exceeded, the monitoring system issues an alarm, and the gas injection and fire suppression system responds, and the gas injection pipe valve 7 is opened to extinguish the fire and prevent coal and gas from spontaneous combustion.

The detonation gas concentration avoids the optimal explosion concentration and is in the range of 5%-9%, 10%-16% in order to manufacture a small-scale gas explosion and avoid the potential danger of high-intensity explosion of gas.

Claims

A thermal stimulation and borehole gas explosion cooperation coal seam secondary anti-reflection device, characterized in that: the device is composed of a microwave radiation system, a borehole gas detonation system, a gas injection fire prevention system and a gas extraction device; The radiation system is composed of a microwave radiation generator (10), a waveguide valve (11), a waveguide (12), and a microwave radiation probe (13), and the microwave radiation probe (13) is externally provided with a protection screen tube (14). The borehole gas detonation system is composed of a borehole gas detonation monitoring device (15), a pulse ignition head (16), a gas concentration sensor (17), and a temperature sensor (18), and the gas injection fire prevention system is injected with heptafluoropropane. The gas pipe (6) and the gas injection pipe valve (7) are composed, the front end of the casing (4) penetrates into the borehole (2), and the rear end is connected with a microwave generator (10), and the casing (4) is terminated with gas. The extraction device (8) and the heptafluoropropane gas injection pipe (6) are connected with a drilling gas detonation monitoring device (15) at the lower end, and the microwave radiation probe (13) and the pulse ignition head (16) are drilled into the hole with the casing (4). (2) Internally, the gas concentration sensor (17) and the temperature sensor (18) are transmitted in the casing (4) in real time through the M12 connector (19). Si concentration and temperatures to monitor the gas detonation apparatus (15).
The method for thermally increasing the thermal disturbance of the apparatus of claim 1 and the secondary gas permeability enhancement of the coal mine gas explosion, comprising the steps of:

a. Drilling and drilling holes (2) in the coal seam to be extracted (1), the inner diameter of the bore (2) is larger than the outer diameter of the casing (4) by 1 to 2 mm;

b. The front end of the sleeve (4) on which the microwave radiation probe (13) and the pulse ignition head (16) are placed is fed into the borehole (2) and sealed with a sealing material (5); the sleeve (4) The front end is arranged to protect the screen tube (3) for supporting the coal seam (1), the rear end of the sleeve (4) is connected to the microwave radiation generator (10), and the upper end of the sleeve (4) extending out of the drill hole (2) is connected a gas extraction device (8) and a heptafluoropropane gas injection pipe (6), extending from the lower end of the casing (4) of the drill hole (2) to the borehole gas detonation monitoring device (15);

c. Turn on the microwave radiation generator (10), perform microwave irradiation on the coal seam (1), heat the coal seam (1) and generate crack holes in the coal seam (1) to promote gas desorption, and carry out the gas extraction device (8). Gas drainage;

d. When the gas emission monitoring device (15) monitors that the gas concentration is 5%-9%, 10%-16%, the ignition pulse ignition head (16) is ignited, the borehole is detonated (2), and the coal seam is (1) Performing a shatter and promoting secondary desorption of coal (1) gas;

e. When the temperature is higher than the threshold of 280 ° C, heptafluoropropane is injected through the heptafluoropropane gas injection pipe (6) to cool the fire;

f. Repeat steps c, d, and e to realize the secondary anti-drainage process of coal seam in thermal disturbance and borehole gas explosion.