CN207073410U - The anti-reflection system of injection hot water and liquid nitrogen is circulated to coal seam - Google Patents

Abstract

The utility model discloses a kind of anti-reflection system that injection hot water and liquid nitrogen are circulated to coal seam, including hot water filling subsystem, liquid nitrogen filling subsystem, two-position three-way valve and coal seam filling subsystem.The invention also discloses the anti-reflection method using above-mentioned anti-reflection system, in turn include the following steps：First step is preparation process, and second step is boiler and liquid nitrogen case fluid injection operation；Third step is hot-water flooding operation；Four steps is drain step；5th step is fluid injection nitrogen operation；6th step is steps of exhausting.Circulation performs third step to the 6th step, until reaching predetermined anti-reflection scope and antireflective effect.Anti-reflection system and anti-reflection method of the present utility model can greatly improve the permeability in depths coal seam, be easy to gas pre-drainage to adopt, and be significant for reducing gas accident and coal-bed-gas production-increase.

Description

Anti-reflection system for circulating hot water and liquid nitrogen into coal seam

technical field

The utility model relates to the technical field of coal and coal bed gas mining, in particular to the coal seam anti-permeability technology.

Background technique

Coal mines are the main source of energy in our country. With the continuous mining and utilization of coal, coal mining has gradually developed to the deep. Affected by ground stress, temperature, etc., the permeability of deeper coal seams decreases, gas is not easy to discharge, and accidents due to gas are very easy to occur during the mining process. Therefore, it is of great safety significance to improve the permeability of deep coal seams and pre-extract coal seam gas. Of course, coalbed methane is flammable, and the extraction of coalbed methane also has positive economic significance.

Domestic scholars have been committed to seeking a variety of technical methods for coal seam pressure relief and permeability enhancement. At present, coal seam pressure relief and permeability enhancement measures mainly include hydraulic punching, hydraulic slotting, mining layer protection, loose blasting and controlled blasting, etc., but these measures have their own existence. Certain flaws. For example, hydraulic punching technology can only be applied to soft coal seams with coal seam hardness f value less than 0.5, which has poor applicability and complicated process; hydraulic slotting technology can increase the natural gas discharge, but the workload is heavy and the protection distance is short; loose blasting and controlled blasting The pollution caused by technical anti-permeability coal is relatively high, and it is prone to excessive local pressure or open flames, and gas explosion accidents when the gas in the roadway exceeds the limit, and the loose blasting technology is mostly used for hard coal seams with weak outburst strength.

Utility model content

The purpose of this utility model is to provide an anti-reflection system that injects hot water and liquid nitrogen into the coal seam circularly, which can simultaneously inject hot water and liquid nitrogen into the coal seam through multiple boreholes, in view of the shortcomings of the existing anti-reflection measures. Greatly improve the permeability of the coal seam, and facilitate the extraction of coal seam gas.

In order to achieve the above purpose, the utility model anti-reflection system for injecting hot water and liquid nitrogen into the coal seam circulation includes a hot water filling subsystem, a liquid nitrogen filling subsystem, a two-position three-way valve and a coal seam filling subsystem;

The hot water filling subsystem includes a hot water pipeline connected to a hot water source, with the flow direction of hot water as the forward direction, and the hot water pipeline is provided with a first pressure reducing valve, a hot water tank and a second A booster pump; the front end of the hot water pipeline communicates with the first port of the two-position three-way valve;

The liquid nitrogen filling subsystem includes a liquid nitrogen pipeline connected to the liquid nitrogen source, with the flow direction of liquid nitrogen as the forward direction, and the second pressure reducing valve, liquid nitrogen tank and The second booster pump; the front end of the liquid nitrogen pipeline is connected with the second interface of the two-position three-way valve; the liquid nitrogen tank and the liquid nitrogen pipeline are respectively provided with insulation layers;

The coal seam filling subsystem includes a filling main pipe connected to the third interface of the two-position three-way valve, a multi-way pipe and several drilling filling structures, and the main filling pipe is provided with a pressure gauge;

The multi-way tube includes an inner tube and an outer tube arranged on the same center line, and a filling cavity with a circular cross section is formed between the inner tube and the outer tube; the outer tube is connected with a liquid inlet port and several liquid outlet ports, and the liquid inlet port is connected to Filling main pipe; each liquid outlet is evenly distributed along the circumference of the outer pipe, and each liquid outlet is connected to a filling connection pipe;

The drilling and filling structure includes branch drilling, and the branch drilling is connected with a filling branch pipe. Hole sealer; the filling branch pipe passes through the hole sealer and its end opens at the bottom of the branched hole; the hole sealer is also pierced with a discharge pipe, and the inner end of the discharge pipe is located inside the hole of the hole sealer And adjacent to the hole sealer, the outer end of the discharge pipe is located outside the hole of the hole sealer; a discharge valve is arranged on the discharge pipe outside the branch hole.

A first check valve is provided on the hot water pipeline between the first booster pump and the two-position three-way valve, and a first check valve is provided on the liquid nitrogen pipeline between the first booster pump and the two-position three-way valve. Second one-way valve.

The first decompression valve, hot water tank, first booster pump, second decompression valve, liquid nitrogen tank, second booster pump, the two-position three-way valve, multi-way pipe and drilling filling The structures are all located in the floor alley.

The utility model has the following advantages:

The utility model can use the liquid nitrogen filling subsystem and the hot water filling subsystem to inject hot water and liquid nitrogen into the coal seam through the drilling cycle, so as to generate temperature impact on the coal body. Both high temperature and low temperature have certain damage to the pore structure of coal and rock mass. Injecting liquid nitrogen after water injection into the coal seam will cause the water in the coal seam to freeze and expand rapidly, and the expansion of the water body greatly expands the damage of the coal body and produces a better anti-permeability effect. The gasification of liquid nitrogen will also increase the pressure of the coal body sharply, further expanding the damage of the coal body. Due to the expansion of coal body damage, after injecting hot water into the coal seam again, the water can penetrate into the coal body in a wider range, and rapidly expand the coal body damage again in the next round of freezing expansion. Such circulating injection of hot water and liquid nitrogen can produce a much better anti-reflection effect than that of simple injection of hot water and liquid nitrogen, and the range of anti-reflection of coal is also greatly improved compared with simple injection of hot water or liquid nitrogen.

The anti-permeability system and anti-permeability method of the utility model can greatly improve the permeability of deep coal seams, facilitate gas pre-extraction, and have great significance for reducing gas accidents and increasing coal bed gas production.

Liquid nitrogen has stable chemical properties, a large number of raw materials (which can be prepared by using the atmosphere), is easy to prepare, and is cheap; the original boilers in the bath center in the mining area and the staff canteen are used as hot water sources to provide hot water, which is convenient for improving the utilization of existing equipment. It has good promotion and application value.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a cross-sectional schematic diagram of a multi-way pipe;

Fig. 3 is a schematic structural view of hot water pipelines and liquid nitrogen pipelines leading into the well;

Fig. 4 is an enlarged view at point A in Fig. 3 .

Detailed ways

As shown in Figures 1 to 4, the anti-reflection system of the utility model for injecting hot water and liquid nitrogen into the coal seam cycle includes a hot water filling subsystem, a liquid nitrogen filling subsystem, a two-position three-way valve 25 and a coal seam filling system. Injection system;

The hot water filling subsystem includes a hot water pipeline 15 connected to a hot water source 14. The hot water flow direction is forward, and the hot water pipeline 15 is provided with a first pressure reducing valve 17, The hot water tank 19 and the first booster pump 21; the front end of the hot water pipeline 15 communicates with the first interface 26 of the two-position three-way valve 25;

The liquid nitrogen filling subsystem includes a liquid nitrogen pipeline 16 connected to the liquid nitrogen source 13, with the flow direction of liquid nitrogen as the forward direction, and the second pressure reducing valve 18 is arranged on the liquid nitrogen pipeline 16 from back to front , liquid nitrogen tank 20, and the second booster pump 22; the front end of the liquid nitrogen pipeline 16 communicates with the second interface 27 of the two-position three-way valve 25; the liquid nitrogen tank 20 and the liquid nitrogen pipeline 16 are respectively provided with Insulation layer; It is a conventional technology to set an insulation layer outside the box and pipeline, and the insulation layer is not shown in the figure.

The coal seam filling subsystem includes a filling main pipe 37 connected to the third interface 28 of the two-position three-way valve 25, a multi-way pipe 42 and several drilling filling structures. The filling main pipe 37 is provided with a pressure gauge 29;

The multi-way pipe 42 includes an inner pipe 33 and an outer pipe 34 arranged concentrically, and a filling chamber 32 with a ring-shaped cross section is formed between the inner pipe 33 and the outer pipe 34; the outer pipe 34 is connected with a liquid inlet port 51 and several The liquid outlet interface 52 and the liquid inlet interface 51 are connected to the filling main pipe 37; each liquid outlet interface 52 is evenly distributed along the circumference of the outer pipe 34, so that the filling amount of hot water and nitrogen in each branch-like borehole is more uniform, increasing The penetration effect is relatively consistent. Each liquid outlet port 52 is respectively connected with a filling connecting pipe 47;

The drilling and filling structure includes a branch bore 41, and the branch bore 41 is connected with a filling branch pipe 43, and the filling branch pipe 43 communicates with a filling connection pipe 47 of the multi-way pipe 42 through the pipeline interface 30, and the branch drill The opening of the hole 41 is provided with a hole sealer 45; the filling branch pipe 43 passes through the hole sealer 45 and its end opens at the bottom of the main hole of the branch-like borehole 41; the hole sealer 45 is also pierced with a discharge pipe 44, the inner end of the discharge pipe 44 is positioned at the inner side of the hole of the hole sealer 45 and is adjacent to the hole sealer 45, and the outer end of the discharge pipe 44 is positioned at the outside of the hole of the hole sealer 45; A discharge valve 46 is provided on the pipe 44 . The pipeline interface 30 can adopt common pipeline connection structures such as flanges. The setting of the pipeline interface 30 is convenient for drilling construction and pipeline connection, and it is convenient to extend the filling connection pipe 47 of the multi-way pipe 42 to the branch borehole 41, and the branch borehole 41 is filled.

The multi-way pipe 42 has a simple structure, and is convenient for circulating hot water and liquid nitrogen to multiple branched boreholes 41 at the same time for anti-reflection operation.

The hot water source 14 is a hot water boiler, and the liquid nitrogen source 13 is a liquid nitrogen tank or a liquid nitrogen production workshop.

The hot water pipeline 15 between the first booster pump 21 and the two-position three-way valve 25 is provided with a first one-way valve 23 , and between the first booster pump 21 and the two-position three-way valve 25 A second one-way valve 24 is provided on the liquid nitrogen pipeline 16 . The first one-way valve 23 and the second one-way valve 24 can prevent the backflow phenomenon from occurring when the gas pressure at the coal seam is greater than the pressure of hot water or liquid nitrogen, especially when the liquid nitrogen gasifies and the pressure in the dendritic borehole 41 increases sharply Prevent backflow from occurring.

The hot water pipeline 15 and the liquid nitrogen pipeline 16 extend to the floor lane 11 of the working face 8 along the horizontal transportation lane 3, the upper (lower) hill 4 of the track and the connecting lane 10; the first pressure reducing valve, The hot water tank, the first booster pump, the second pressure reducing valve, the liquid nitrogen tank, the second booster pump, the two-position three-way valve 25, the multi-way pipe 42 and the drilling filling structure are all located in the floor lane 11 Inside. This setting is convenient for existing installation and arrangement of the utility model.

Among them, the hot water source 14 is preferably a coal-fired hot water boiler, which can use coal resources to produce hot water on site. Parts such as hole sealing device 45, liquid nitrogen tank 20, one-way valve, two-position three-way valve 25 and booster pump are all existing conventional devices, and the specific structure is no longer described in detail.

In Figure 3, the number 1 is the main well, the number 2 is the auxiliary well, the number 3 is the horizontal transportation alley, the number 4 is the track up (down) hill; the number 5 is the transportation up (down) hill; the number 6 is the return air lane The number 7 is the transportation trough; the number 8 is the working face; the number 9 is the return air chute; the number 10 is the connection lane; the number 11 is the floor lane;

Among Fig. 1, label 38 is a coal seam, label 39 is a coal seam roof, and label 40 is a coal seam floor.

The utility model also discloses an anti-reflection method using the above-mentioned anti-reflection system that injects hot water and liquid nitrogen into the coal seam circulatingly, and proceeds in turn according to the following steps:

The first step is a preparatory step, including drilling and connection operations; the drilling operation refers to drilling the branch-like borehole 41 on the downhole working face 8; Connected, the components of the liquid nitrogen filling subsystem are connected through the liquid nitrogen pipeline 16, and the drilling filling structure and the multi-way pipe 42 are connected; the hot water filling subsystem, the liquid nitrogen filling subsystem, and the liquid nitrogen filling The filling subsystem is connected with the coal seam filling subsystem; close the two-position three-way valve 25, the first pressure reducing valve 17, the second pressure reducing valve 18 and the discharge valve 46;

The second step is the liquid injection operation of the hot water tank 19 and the liquid nitrogen tank 20; the first decompression valve 17 is opened, the hot water provided by the hot water source 14 is injected into the hot water tank 19 through the hot water pipeline 15, and the second decompression valve is opened simultaneously. Pressure valve 18, through the liquid nitrogen pipeline 16, the liquid nitrogen provided by the liquid nitrogen source 13 is injected into the liquid nitrogen tank 20;

The third step is hot water injection operation; first connect the first interface 26 and the third interface 28 of the two-position three-way valve 25, and then start the first booster pump 21 to pump the hot water in the hot water tank 19 To the multi-way pipe 42, hot water enters each filling branch pipe 43 and then enters each branch-like borehole 41 by each outlet port 52 of the multi-way pipe 42; continuously injects hot water in each branch-like borehole 41, and the Keep the predetermined pressure for more than 10 minutes after the display reaches the predetermined pressure value, and the predetermined pressure is above 5MPa;

The fourth step is a drainage step; close the first booster pump 21, slowly open the discharge valve 46, discharge the water in the branch-like borehole 41, and then close the discharge valve 46;

The fifth step is to inject liquid nitrogen; first connect the second interface 27 and the third interface 28 of the two-position three-way valve 25, and then start the second booster pump 22 to pump the liquid nitrogen in the liquid nitrogen tank 20 To the multi-way pipe 42, liquid nitrogen enters each filling branch pipe 43 and then enters each branch-like borehole 41 from each outlet port 52 of the multi-way pipe 42; continuously injects liquid nitrogen into each branch-like borehole 41, and the pressure gauge 29 After the reading reaches the predetermined pressure value, keep the predetermined pressure for more than 10 minutes, and the predetermined pressure is above 5MPa; the holding pressure and time can be set according to the anti-reflection radius of the drill hole.

The sixth step is the exhaust step; liquid nitrogen is gasified at the branch hole 41, close the second booster pump 22, slowly open the discharge valve 46, discharge the low-temperature gas in the branch hole 41, and then close the discharge valve 46;

The third step to the sixth step are executed cyclically until the predetermined anti-reflection range and anti-reflection effect are reached.

It also includes the seventh step, that is, the gas extraction step. This step is to connect the discharge pipe 44 with an external gas extraction system to perform extraction operations on the gas in the coal seam. The gas drainage system is an existing technology, and the specific structure will not be described in detail, and the figure is not shown.

The above embodiments are only used to illustrate and not limit the technical solutions of the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present utility model can still be modified or equivalently replaced. Any modification or partial replacement without departing from the spirit and scope of the present utility model shall fall within the scope of the claims of the present utility model.

Claims (3)

1. The anti-reflection system for injecting hot water and liquid nitrogen into the coal seam is characterized in that it includes a hot water filling subsystem, a liquid nitrogen filling subsystem, a two-position three-way valve, and a coal seam filling subsystem; The hot water filling subsystem includes a hot water pipeline connected to a hot water source, with the flow direction of hot water as the forward direction, and the hot water pipeline is provided with a first pressure reducing valve, a hot water tank and a second A booster pump; the front end of the hot water pipeline communicates with the first port of the two-position three-way valve; The liquid nitrogen filling subsystem includes a liquid nitrogen pipeline connected to the liquid nitrogen source, with the flow direction of liquid nitrogen as the forward direction, and the second pressure reducing valve, liquid nitrogen tank and The second booster pump; the front end of the liquid nitrogen pipeline is connected with the second interface of the two-position three-way valve; the liquid nitrogen tank and the liquid nitrogen pipeline are respectively provided with insulation layers; The coal seam filling subsystem includes a filling main pipe connected to the third interface of the two-position three-way valve, a multi-way pipe and several drilling filling structures, and the main filling pipe is provided with a pressure gauge; The multi-way tube includes an inner tube and an outer tube arranged on the same center line, and a filling cavity with a circular cross section is formed between the inner tube and the outer tube; the outer tube is connected with a liquid inlet port and several liquid outlet ports, and the liquid inlet port is connected to Filling main pipe; each liquid outlet is evenly distributed along the circumference of the outer pipe, and each liquid outlet is connected to a filling connection pipe; The drilling and filling structure includes branch drilling, and the branch drilling is connected with a filling branch pipe. Hole sealer; the filling branch pipe passes through the hole sealer and its end opens at the bottom of the branched hole; the hole sealer is also pierced with a discharge pipe, and the inner end of the discharge pipe is located inside the hole of the hole sealer And adjacent to the hole sealer, the outer end of the discharge pipe is located outside the hole of the hole sealer; a discharge valve is arranged on the discharge pipe outside the branch hole. 2. The anti-permeation system for circularly injecting hot water and liquid nitrogen into the coal seam according to claim 1, characterized in that: the hot water pipeline between the first booster pump and the two-position three-way valve is provided with a second A one-way valve, a second one-way valve is provided on the liquid nitrogen pipeline between the first booster pump and the two-position three-way valve. 3. The anti-permeation system for circularly injecting hot water and liquid nitrogen into the coal seam according to claim 2, characterized in that: the first pressure reducing valve, the hot water tank, the first booster pump, and the second pressure reducing valve , the liquid nitrogen tank, the second booster pump, the two-position three-way valve, the multi-way pipe and the drilling filling structure are all located in the floor lane.