Coal mine ventilation air methane concentration detection device

Abstract

The utility model belongs to the technical field of methane gas detection, and discloses a coal mine ventilation air methane concentration detection device. Comprising a multi-gas-source mixing device and a multiple methane concentration detection heating device, the low-concentration gas pipeline, the mine ventilation air methane pipeline, the fresh air pipeline and the regenerative flue gas pipeline are connected with the multi-gas-source mixing device; an outlet of the multi-gas-source mixing device is connected with the multiple methane concentration detection heating device through a mixed gas pipeline; the multiple methane concentration detection heating device comprises a heating device shell, a flow guide plate, a heating pipe and a methane concentration detection device, the guide plate is mounted at the foremost end of the middle position in the heating device shell, and the rear end of the guide plate is sequentially connected with the heating pipe and the methane concentration detection device; the utility model solves the problem that the methane concentration of the mixed gas obtained by mixing the coal mine ventilation air methane and the low-concentration gas is not accurately detected due to the fact that the moisture in the ventilation air methane and the low-concentration gas is large.

Description

Technical Field

[0001] This utility model belongs to the field of methane gas detection technology, specifically a methane concentration detection device for coal mine exhaust gas. Background Technology

[0002] Methane gas, a gas with a strong greenhouse effect, is receiving increasing attention, and mines are increasingly utilizing coal mine exhaust gas. The main method involves mixing the exhaust gas with gas from extraction pump stations to achieve processes such as oxidation heating and oxidation heating power generation. However, when methane mixed with air reaches a certain concentration, it can ignite or explode upon contact with a high-temperature ignition source, potentially causing numerous casualties among workers. Therefore, detecting methane concentration in coal mine exhaust gas is crucial. However, due to the high moisture content in exhaust gas and low-concentration methane, the methane concentration in the mixed gas is often inaccurate, posing a safety hazard. Utility Model Content

[0003] This invention overcomes the shortcomings of the prior art and proposes a methane concentration detection device for coal mine exhaust gas; it solves the problem that the methane concentration detection of the mixed gas after coal mine exhaust gas and low-concentration methane is inaccurate due to the high moisture content in exhaust gas and low-concentration methane.

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

[0005] A coal mine exhaust gas methane concentration detection device includes a multi-source blending device, a multi-methane concentration detection heating device, a coal mine low-concentration gas supply system, a mine exhaust gas supply system, an outdoor fresh air system, and a waste heat boiler tail-end regenerated flue gas pipeline. The coal mine low-concentration gas supply system, the mine exhaust gas supply system, the outdoor fresh air system, and the waste heat boiler tail-end regenerated flue gas pipeline are each connected to the multi-source blending device via pipelines. The outlet of the multi-source blending device is connected to the multi-methane concentration detection heating device via a mixed gas pipeline. The outlet of the multi-methane concentration detection heating device is connected to the gas supply for an RTO or an internal combustion engine generator set via a pipeline.

[0006] The multiple methane concentration detection heating device includes a heating device housing, a guide plate, a heating tube, and a methane concentration detection device; the guide plate is installed at the front end of the middle position inside the heating device housing, and the rear end of the guide plate is connected to the heating tube and the methane concentration detection device in sequence.

[0007] Furthermore, the rear end of the heating tube is sequentially connected to a first-stage laser methane concentration meter sleeve, a second-stage laser methane concentration meter sleeve, and a third-stage infrared methane concentration meter sleeve; the first-stage laser methane concentration meter sleeve is equipped with a first laser methane concentration meter, the second-stage laser methane concentration meter sleeve is equipped with a second laser methane concentration meter, and the third-stage infrared methane concentration meter sleeve is equipped with an infrared methane concentration meter.

[0008] Furthermore, it also includes a PLC control system, wherein the first laser methane concentration meter, the second laser methane concentration meter, and the infrared methane concentration meter are respectively connected to the PLC control system; a main shut-off valve is installed on the mixed gas pipeline; and the PLC control system is connected to the main shut-off valve.

[0009] Furthermore, a temperature sensor is also installed on the sleeve of the primary laser methane concentration meter, and the PLC control system is connected to the temperature sensor.

[0010] Furthermore, the heating tube has a sleeve structure, with an inlet water collection pipe connected to the front end of the outer layer of the sleeve and an outlet water collection pipe connected to the rear end of the outer layer of the sleeve.

[0011] Furthermore, the outer wall of the heating tube is provided with a heat insulation layer.

[0012] Furthermore, the two ends of the heating device housing are connected to the air duct; the inlet water collection pipe and the outlet water collection pipe are located outside the heating device housing.

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

[0014] This invention utilizes a heating device to heat a small portion of the fluid, reducing the relative humidity in the fluid to achieve accurate methane concentration monitoring. It effectively solves the problem of inaccurate methane concentration detection caused by high humidity in exhaust gas and coal mine gas. It features high reliability, good safety, easy installation, and low cost, and can be applied to coal mine gas oxidation heating projects. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the coal mine exhaust gas methane concentration detection device described in this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of a multiple methane concentration detection heating device;

[0017] Figure 3 yes Figure 2 Sectional view along line AA;

[0018] Figure label:

[0019] 1. Multi-source gas mixing device; 2. Multiple methane concentration detection and heating device; 3. Coal mine low-concentration gas supply system; 4. Mine exhaust gas supply system; 5. Outdoor fresh air system; 6. Waste heat boiler tail regenerated flue gas pipeline; 7. Main shut-off valve; 8. PLC control system;

[0020] 21. Flow guide plate; 22. Insulation layer; 23. Heating tube; 24. Inlet water collection pipe; 25. Outlet water collection pipe; 26. Heating zone; 27. Measurement zone; 28. First-stage laser methane concentration meter sleeve; 29. ​​Second-stage laser methane concentration meter sleeve; 210. Third-stage infrared methane concentration meter sleeve; 211. Heating device housing; 212. Air duct. Detailed Implementation

[0021] 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.

[0022] See Figures 1 to 3 This embodiment proposes a coal mine exhaust gas methane concentration detection device, including a multi-source mixing device 1, a multi-methane concentration detection heating device 2, a coal mine low-concentration gas supply system 3, a mine exhaust gas supply system 4, an outdoor fresh air system 5, a waste heat boiler tail reheat flue gas pipeline 6, a main shut-off valve 7, and a PLC control system 8.

[0023] The coal mine low-concentration gas supply system 3, the mine exhaust gas supply system 4, the outdoor fresh air system 5, and the waste heat boiler tail-end regenerated flue gas pipeline 6 are respectively connected to the multi-source blending device 1 through pipelines. The outlet of the multi-source blending device 1 is connected to the multiple methane concentration detection and heating device 2 through a mixed gas pipeline, and a main shut-off valve 7 is installed on the mixed gas pipeline. The multi-source blending device 1 uses the coal mine low-concentration gas supply system 3, the exhaust gas from the mine exhaust gas supply system 4, and the waste heat boiler tail-end regenerated flue gas pipeline 6 to mix with the air supplied by the outdoor fresh air system 5, maintaining the methane concentration at the outlet of the multi-source blending device 1 at 1.2% and the temperature above 5°C. Then, the multiple methane concentration detection and heating device 2 installed at the outlet of the multi-source blending device 1 accurately measures the methane concentration of the mixed gas, ensuring blending accuracy. The outlet of the multiple methane concentration detection heating device 2 is connected to the gas supply of the RTO or internal combustion engine generator set via a pipeline.

[0024] The multiple methane concentration detection heating device 2 consists of a guide plate 21, a heat insulation layer 22, a heating tube 23, an inlet water collection pipe 24, an outlet water collection pipe 25, a first-stage laser methane concentration meter sleeve 28, a second-stage laser methane concentration meter sleeve 29, a third-stage infrared methane concentration meter sleeve 210, a heating device housing 211, and an air duct 212.

[0025] The flow guide plate 21, heat insulation layer 22, heating tube 23, first-stage laser methane concentration meter sleeve 28, second-stage laser methane concentration meter sleeve 29, and third-stage infrared methane concentration meter sleeve 210 are installed inside the heating device housing 211; the inlet water collection pipe 24 and the outlet water collection pipe 25 are located outside the heating device housing 211, and both ends of the heating device housing 211 are connected to the air duct 212.

[0026] The guide plate 21 is installed at the frontmost position in the middle of the heating device housing 211. The rear end of the guide plate 21 is sequentially connected to the heating tube 23, the primary laser methane concentration meter sleeve 28, the secondary laser methane concentration meter sleeve 29, and the tertiary infrared methane concentration meter sleeve 210. The outer wall of the heating tube 23 is provided with a heat insulation layer 22. The heating tube 23 and the heat insulation layer 22 form a heating zone for heating the mixed gas entering the heating tube 23. The primary laser methane concentration meter sleeve 28, the secondary laser methane concentration meter sleeve 29, and the tertiary infrared methane concentration meter sleeve 210 form a measurement zone. The primary laser methane concentration meter sleeve 28 is used to install the #1 laser methane concentration meter, the secondary laser methane concentration meter sleeve 29 is used to install the #2 laser methane concentration meter, and the tertiary infrared methane concentration meter sleeve 210 is used to install the #3 infrared methane concentration meter. The instruments are intrinsically safe detection instruments, and the instruments adopt dustproof and waterproof measures to reduce the impact of changes in gas parameters inside the pipeline on the detection accuracy. The No. 1 laser methane concentration meter, No. 2 laser methane concentration meter and No. 3 infrared methane concentration meter are respectively connected to the PLC control system 8. A temperature sensor is also installed on the sleeve 28 of the first-stage laser methane concentration meter. The PLC control system 8 is connected to the temperature sensor and the main shut-off valve 7.

[0027] The mixed gas enters the heating device housing 211 through the front air duct 212. A portion of the mixed gas enters the heating tube 23 through the guide plate 21 and is heated to remove the moisture contained in the mixed gas. Then, this portion of the mixed gas sequentially enters the first-stage laser methane concentration meter sleeve 28, the second-stage laser methane concentration meter sleeve 29, and the third-stage infrared methane concentration meter sleeve 210, and the concentration is detected by the laser methane concentration meter and infrared methane concentration meter in these sleeves. The mixed gas outside the heating tube 23 is sent to the RTO or the gas used by the internal combustion engine generator set through the rear air duct 212.

[0028] In this embodiment, the guide plate 21 is designed with a certain tilt angle to reduce fluid resistance and avoid fluid turbulence; the heating tube 23 is made of stainless steel and has a sleeve structure. Hot water is introduced into the outer layer of the sleeve, and the inner layer is used for the passage of mixed gas; the hot water transfers heat to the mixed gas, raising the temperature of the mixed gas and reducing the relative humidity, ensuring accurate measurement of methane concentration by the meter; a heat insulation layer 22 is set on the outside of the heating tube 23, and refractory heat insulation material is added to the heat insulation layer 22 to reduce heat loss into the external gas of the heating tube 23 and reduce the heat source required for heating.

[0029] Hot water enters the outer layer of the heating pipe 23 through the inlet water collection pipe 24 to heat the inner pipe wall, thereby further heating the mixed gas. After the heat exchange is completed, the hot water enters the external heat source system through the outlet water collection pipe 25 to be heated, and then enters the inlet water collection pipe 24 again, and the cycle repeats.

[0030] The heating fluid inside the heating tube 23 can be hot water, steam, or flue gas.

[0031] The gas mixture is heated by the heating tube 23 to reduce the relative humidity in the gas, thereby preventing gas atomization caused by excessive humidity, reducing the working wear of the methane concentration meter, and improving the detection accuracy of the methane concentration detector.

[0032] The methane concentration meter further ensures measurement accuracy and increases reliability by employing multi-level concentration measurement and combining infrared and laser technologies.

[0033] The specific working principle is as follows: After the coal mine exhaust air or gas in the air duct 212 enters the heating device shell 211, a small portion enters the heating zone through the guide plate 21. The heating tube 23 in the heating zone heats the gas with hot water to reduce humidity. The heating tube 23 is equipped with a heat insulation layer 22 on the outside to prevent heat loss. The heated coal mine exhaust air or gas enters the measurement zone and flows out of the heating device after passing through the first-stage laser methane concentration meter sleeve 28, the second-stage laser methane concentration meter sleeve 29, and the third-stage infrared methane concentration meter sleeve 210.

[0034] 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 coal mine ventilation air methane concentration detection device, characterized in that, It comprises a multi-gas source mixing device (1), a multi-methane concentration detection heating device (2), a coal mine low-concentration gas supply system (3), a mine ventilation air supply system (4), an outdoor fresh air system (5), and a waste heat boiler tail back heat flue gas pipeline (6); the coal mine low-concentration gas supply system (3), the mine ventilation air supply system (4), the outdoor fresh air system (5), and the waste heat boiler tail back heat flue gas pipeline (6) are connected with the multi-gas source mixing device (1) through pipelines; the outlet of the multi-gas source mixing device (1) is connected with the multi-methane concentration detection heating device (2) through a mixed gas pipeline; the outlet of the multi-methane concentration detection heating device (2) is connected to an RTO or an internal combustion engine generator set through a pipeline. The multi-methane concentration detection heating device (2) comprises a heating device shell (211), a flow guide plate (21), a heating pipe (23), and a methane concentration detection device; the flow guide plate (21) is installed at the most front end of the middle position inside the heating device shell (211), and the rear end of the flow guide plate (21) is sequentially connected with the heating pipe (23) and the methane concentration detection device.

2. The coal mine ventilation air methane concentration detection device according to claim 1, characterized in that, The rear end of the heating pipe (23) is sequentially connected with a first laser methane concentration instrument sleeve (28), a second laser methane concentration instrument sleeve (29), and a third infrared methane concentration instrument sleeve (210); the first laser methane concentration instrument sleeve (28) is installed with a first laser methane concentration instrument, the second laser methane concentration instrument sleeve (29) is installed with a second laser methane concentration instrument, and the third infrared methane concentration instrument sleeve (210) is installed with an infrared methane concentration instrument.

3. The coal mine ventilation air methane concentration detection device of claim 2, wherein, It also comprises a PLC control system (8), the first laser methane concentration instrument, the second laser methane concentration instrument, and the infrared methane concentration instrument are connected with the PLC control system (8) respectively; a total cut-off valve (7) is arranged on the mixed gas pipeline; the PLC control system (8) is connected with the total cut-off valve (7).

4. The coal mine ventilation air methane concentration detection device of claim 3, wherein, A temperature sensor is further arranged on the first laser methane concentration instrument sleeve (28), and the PLC control system (8) is connected with the temperature sensor.

5. The coal mine ventilation air methane concentration detection device of claim 1, wherein, The heating pipe (23) is in a sleeve structure, the front end of the outer layer of the sleeve is connected with a water inlet collecting pipe (24), and the rear end of the outer layer of the sleeve is connected with a water outlet collecting pipe (25).

6. The coal mine ventilation air methane concentration detection device of claim 1, wherein, An insulating layer (22) is arranged on the outer wall of the heating pipe (23).

7. The coal mine ventilation air methane concentration detection device of claim 5, wherein, The heating device shell (211) is connected with an air duct (212) at both ends; the water inlet collecting pipe (24) and the water outlet collecting pipe (25) are located outside the heating device shell (211).

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