Positive pressure and negative pressure combined coal mine beam tube sampling system and sampling method thereof

Abstract

The invention relates to the technical field of coal mine safety monitoring, in particular to a positive pressure and negative pressure combined coal mine beam tube sampling system and a sampling method thereof.The sampling system comprises multiple samplers used for collecting gas samples in an underground to-be-detected area, each sampler is communicated with a sample feeding end of a first electromagnetic valve through a beam tube, emptying ends of the plurality of first electromagnetic valves are communicated with a suction inlet of an air extracting pump through a main pipeline, and an air outlet of the air extracting pump is communicated with an air inlet of a pretreatment control system; the sampling beam tube is communicated with a sample feeding end of a second electromagnetic valve through a sampling header tube, an air inlet end of the second electromagnetic valve is communicated with a suction inlet of the positive pressure air pump, and an emptying end of the second electromagnetic valve is communicated with the pretreatment control system; and an exhaust port of the positive pressure air pump is communicated with the analysis unit. According to the invention, the equipment cost can be greatly reduced, cyclic monitoring of a plurality of sampling points can be realized through the switching valve, and the utilization efficiency of the system is improved.

Description

Technical Field

[0001] This invention relates to the field of coal mine safety monitoring technology, and in particular to a coal mine bundle tube sampling system and sampling method that uses a combination of positive and negative pressure. Background Technology

[0002] Bundle tube monitoring systems are a core technology for coal mine fire prediction. By laying bundle tubes, gas samples from key underground areas are continuously drawn into an analyzer for analysis, thereby enabling early warning of the coal spontaneous combustion process.

[0003] The core configuration of a traditional positive pressure sampling system is a "one pump, two pipes" mode, which uses a positive pressure booster pump to provide positive pressure driving force for both the sampling pipe and the return pipe. The sampling pipe is used to transport the sample extracted from the sampling point to the analyzer for sampling. After being processed by the analyzer, the sample is transported to the sample pretreatment control system through the return pipe, instead of being directly discharged into the environment.

[0004] The initial design aimed to simplify the pipeline layout, but when the number of downhole sampling points exceeds the pump's load limit, the system must be expanded by adding gas delivery pumps. For example, if 20 sampling points need to be monitored, and each pump is designed to handle 2 lines, at least 10 gas delivery pumps, along with their power supplies and control modules, are required.

[0005] This "linear superposition" expansion method directly leads to:

[0006] 1. Hardware procurement costs have increased exponentially;

[0007] 2. The space occupied by downhole equipment has increased significantly;

[0008] 3. Power consumption and maintenance workload are increasing simultaneously;

[0009] Therefore, there is an urgent need for a coal mine bundle tube sampling system and sampling method that can shorten transmission time, ensure sample authenticity, and have strong anti-interference capabilities. Summary of the Invention

[0010] To address the aforementioned issues, this invention provides a coal mine bundled tube sampling system and method that combines positive and negative pressure. The system aims to extract gas samples from the target area in the coal mine using negative pressure and process them in a sample pretreatment control system. When sampling is required, positive pressure is used to push the collected gas from the target area into the underground analyzer. A single negative pressure pump can simultaneously drive multiple bundled tubes to sample gas from multiple target areas, thereby reducing equipment and labor costs and system energy consumption.

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A coal mine sampling system using a combined positive and negative pressure tube includes: multiple samplers for collecting gas samples from an underground testing area; each sampler is connected to the sample delivery end of a first solenoid valve via a tube bundle; the vent ends of the multiple first solenoid valves are connected to the inlet of a suction pump via a main pipeline; the outlet of the suction pump is connected to the inlet of a pretreatment control system; the sampling tube bundle is connected to the sample delivery end of a second solenoid valve via a sampling manifold; the inlet of the second solenoid valve is connected to the inlet of a positive pressure pump; the vent end of the second solenoid valve is connected to the pretreatment control system; and the outlet of the positive pressure pump is connected to an analysis unit.

[0013] Furthermore, it also includes: a PLC control module, which is electrically connected to the control terminals of multiple first solenoid valves and second solenoid valves, and is used to control the switching state of the two.

[0014] Furthermore, both the first and second solenoid valves are two-position three-way solenoid valves.

[0015] Furthermore, the analysis unit is used to perform concentration analysis on the gas;

[0016] Furthermore, the analysis unit is used to perform component analysis on the gas;

[0017] Furthermore, the pretreatment control system is used to process the air and then exhaust the processed air.

[0018] The present invention also provides a sampling method based on the above sampling system, comprising the following steps:

[0019] S1: System deployment and preparation;

[0020] Multiple samplers are buried at multiple monitoring points in the goaf. Each sampler is connected to the air inlet of the corresponding first solenoid valve through a corresponding bundle tube. At the same time, the vent ends of all first solenoid valves are connected to the suction port of the air pump through the main pipe. The exhaust port of the air pump is connected to the pretreatment control system. The sample delivery end of each first solenoid valve is connected to a sampling bundle tube. Multiple sampling tubes are connected to the sample delivery end of the second solenoid valve through the sampling main pipe. The vent end of the second solenoid valve is connected to the pretreatment control system. The air inlet of the second solenoid valve is connected to the air inlet of the positive pressure pump. The air outlet of the positive pressure pump is connected to the sample inlet of the analysis unit.

[0021] S2: Negative pressure exhaust pipe;

[0022] The PLC module controls the connection between the air inlet and outlet of all first solenoid valves and starts the air pump to quickly pump the gas from multiple sampling points in the area to be tested through the corresponding number of samplers and bundle tubes to the pre-processing control system for processing, and then discharges the gas after processing.

[0023] S3: Channel switching;

[0024] The PLC module controls the first solenoid valve to change from connecting the air inlet and the vent to connecting the air inlet and the sample delivery end, thereby disconnecting the bundle tube from the main pipeline. At the same time, it controls the second solenoid valve to connect the air inlet and the sample delivery end.

[0025] S4: Push the sample under positive pressure to analysis unit 1 for testing, and switch to emptying state after the test is completed;

[0026] The positive pressure air pump is started, and the gas sample collected by the sampler corresponding to the bundle tube is pressed into the analysis unit for analysis by the positive pressure air pump. After the analysis is completed, the air inlet and outlet of the second solenoid valve are connected, and the analyzed gas sample enters the pre-processing control system for processing and then is discharged.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. Significantly reduces equipment costs: Taking an average system with 16 sampling points as an example, the traditional method requires 8 positive pressure air pumps, while the sampling system using this invention only needs one positive pressure pump and one negative pressure air pump, which greatly saves costs.

[0029] 2. Reduced installation and maintenance costs: Due to the reduction in sampling equipment, installation and maintenance costs have also decreased significantly.

[0030] 3. Energy saving and consumption reduction: The intelligent control system dynamically adjusts the pump operating frequency, avoiding the energy consumption accumulation caused by the independent operation of multiple pumps in the traditional solution, thus greatly reducing energy consumption.

[0031] 4. One pipe for multiple uses: A single system can achieve cyclic monitoring of multiple sampling points through switching valves, which improves the system utilization efficiency. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of the all-round autonomous vacuum cleaner and crease cleaning machine of the present invention;

[0033] In the diagram: 1. Analysis unit; 2. Air pump; 3. Positive pressure air pump; 4. First solenoid valve; 5. Main pipeline; 6. Second solenoid valve; 7. Sampling pipeline; 8. Pretreatment control system; 9. Sampler; 10. Inlet end; 11. Flow regulating valve. Detailed Implementation

[0034] The technical solutions adopted in this invention will be clearly and completely explained and described below with reference to the accompanying drawings and specific embodiments;

[0035] First, this invention provides a coal mine bundled tube sampling system that combines positive and negative pressure, such as... Figure 1 As shown, it includes: a pretreatment control system 8, a sampler 9, a vacuum pump 2, a positive pressure pump 3, an analysis unit 1, a first solenoid valve 4, a second solenoid valve 6, a main pipeline 5, and a sampling pipeline 7, wherein:

[0036] Sampler 9 is used to collect gas samples from the area to be tested underground, such as a goaf. Multiple samplers can be configured according to monitoring needs; in this embodiment, for example... Figure 1 As shown, there are eight samplers 9. When multiple samplers 9 are set, they can be buried in sampling points in different areas of the goaf.

[0037] The first solenoid valve 4 is a two-position three-way solenoid valve. The number of solenoid valves is matched with the number of samplers. Each sampler 9 is connected to the air inlet (point A) of the corresponding first solenoid valve 4 through a bundle tube. The sampling end (point P) of each first solenoid valve 4 is connected to a sampling bundle tube. The venting end (point R) of each first solenoid valve 4 is connected to the suction port of the air pump 2 through the main pipeline 5.

[0038] The air pump 2, as a negative pressure air extraction device, is used to generate negative pressure to quickly draw gas samples collected by multiple collectors 9 to the pretreatment control system 8. It can be installed in the underground chamber. The air outlet of the air pump 2 is connected to the air inlet of the pretreatment control system 8 through a bundle tube.

[0039] When the inlet end of the first solenoid valve 4 is connected to the outlet end, that is, when point A is connected to point R, the negative pressure of the vacuum pump 2 is used to simultaneously draw the gas collected by multiple samplers 9 into the vacuum pump 2 through the main pipeline 5 and multiple bundle tubes. After mixing, the gas is discharged from the exhaust port of the vacuum pump 2 into the pretreatment control system 8.

[0040] The pretreatment control system 8 is used to treat the air, such as removing dust and dehumidifying, and then exhausting the treated air.

[0041] Multiple sampling bundles connected to the sampling end (point P) of the first solenoid valve 4 are connected to the sampling end (point P) of the second solenoid valve 6 through a sampling manifold 7. The second solenoid valve 6 is also a two-position three-way solenoid valve. Its air inlet (point A) is connected to the suction port of the positive pressure air pump 3, and its air outlet (point R) is connected to the pretreatment control system 8.

[0042] Positive pressure gas pump 3: used to generate positive pressure gas. The outlet of positive pressure gas pump 3 is connected to the inlet end 10 of analysis unit 1. When the sample delivery end of the second solenoid valve 6 is connected to the inlet end, that is, when point P is connected to point A, the sample gas collected by sampler 9 at the sampling point in that area can be sent into analysis unit 1 through positive pressure gas pump 3 by controlling the first solenoid valve 4 corresponding to the sampling point in different areas, so that the sample delivery end of the first solenoid valve 4 is connected to the inlet end, that is, point P of the first solenoid valve 4 is connected to point A.

[0043] By using a corresponding number of bundle tubes, independent gas transmission between multiple sampling points can be achieved, avoiding cross-contamination;

[0044] Analysis unit 1 is used to analyze the composition and concentration of gas samples. Analysis unit 1 integrates a gas sensor, enabling real-time detection and data output of target gases such as methane and natural gas. Preferably, the inlet 10 of analysis unit 1 is also equipped with a flow regulating valve 11, which can be adjusted according to the gas sample flow rate to prevent high-pressure gas from impacting analysis unit 1. The outlet of analysis unit 1 is connected to the pretreatment control system 8, used to discharge the gas sample analyzed by analysis unit 1 into the pretreatment control system 8 for further processing and then venting.

[0045] The PLC control module is electrically connected to the control terminals of multiple first solenoid valves 4 and second solenoid valves 6 to control their on / off states.

[0046] Secondly, the sampling method based on the above sampling system includes the following steps:

[0047] S1: System deployment and preparation;

[0048] Multiple samplers 9 are buried at multiple monitoring points in the goaf area. Each sampler 9 is connected to the air inlet (point A) of the corresponding first solenoid valve 4 through a corresponding bundle tube. At the same time, the vent ends (point R) of all first solenoid valves 4 are connected to the suction port of the suction pump 2 through the main pipe. The exhaust port of the suction pump 2 is connected to the pretreatment control system 8. The sample delivery end (point P) of each first solenoid valve 4 is connected to a sampling bundle tube. Multiple sampling tubes are connected to the sample delivery end (point P) of the second solenoid valve 6 through the sampling main pipe 7. The vent end (point R) of the second solenoid valve 6 is connected to the pretreatment control system 8. The air inlet end (point A) of the second solenoid valve 6 is connected to the air inlet of the positive pressure pump 3. The air outlet of the positive pressure pump 3 is connected to the sample inlet 10 of the analysis unit 1.

[0049] S2: Negative pressure exhaust pipe;

[0050] The PLC module controls the connection between the air inlet (point A) and the air outlet (point R) of all first solenoid valves 4, and turns on the air pump 2 to quickly pump the gas from multiple sampling points in the area to be tested through the corresponding number of samplers 9 and bundle tubes via the main pipeline 5 to the pre-processing control system 8 for processing, and then discharges the gas.

[0051] S3: Channel switching;

[0052] By controlling the PLC module, the connection between the inlet end (point A) and the vent end (point R) of any first solenoid valve 4 is changed to the connection between the inlet end (point A) and the sample delivery end (point P), thereby disconnecting the bundle tube from the main pipeline 5. At the same time, the connection between the inlet end (point A) and the sample delivery end (point P) of the second solenoid valve 6 is achieved, thus connecting the bundle tube to the sampling main pipe 7, thereby realizing channel switching.

[0053] S4: Push the sample under positive pressure to analysis unit 1 for testing, and switch to emptying state after the test is completed;

[0054] Start the positive pressure air pump 3. The gas sample collected by the sampler 9 corresponding to the bundle tube is pressed into the analysis unit 1 for analysis by the positive pressure air pump 3. After the analysis is completed, close the second solenoid valve 6, that is, control the air inlet (point A) and the air outlet (point R) of the second solenoid valve 6 to conduct, and send the analyzed gas sample into the pre-processing control system 8 for processing and then venting.

[0055] Finally, the above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A coal mine bundled tube sampling system that combines positive and negative pressure, characterized in that, include: A sampler for collecting gas samples from the area to be tested downhole is provided. Multiple samplers are provided. Each sampler is connected to the sample delivery end of a first solenoid valve through a bundle tube. The venting ends of multiple first solenoid valves are connected to the suction port of a pump through a main pipeline. The outlet of the pump is connected to the inlet of a pretreatment control system. The sampling bundle tube is connected to the sampling end of the second solenoid valve through the sampling main tube, the air inlet of the second solenoid valve is connected to the suction port of the positive pressure air pump, and the venting end of the second solenoid valve is connected to the pretreatment control system. The outlet of the positive pressure air pump is connected to the analysis unit.

2. The coal mine bundled tube sampling system using combined positive and negative pressure as described in claim 1, characterized in that, Also includes: The PLC control module is electrically connected to the control terminals of multiple first and second solenoid valves to control their on / off states.

3. The coal mine bundled tube sampling system using combined positive and negative pressure as described in claim 1, characterized in that, Both the first and second solenoid valves are two-position three-way solenoid valves.

4. A coal mine bundled tube sampling system using combined positive and negative pressure as described in claim 1, characterized in that, The analysis unit is used to perform concentration analysis on the gas.

5. A coal mine bundled tube sampling system using combined positive and negative pressure as described in claim 1, characterized in that, The analysis unit is used to perform component analysis on the gas.

6. A coal mine bundled tube sampling system using combined positive and negative pressure as described in claim 1, characterized in that, The pretreatment control system is used to process the air and then discharge the processed air.

7. The sampling method of the coal mine bundled tube sampling system using combined positive and negative pressure as described in claim 1, characterized in that, Includes the following steps: S1: System deployment and preparation; Multiple samplers are buried at multiple monitoring points in the goaf. Each sampler is connected to the air inlet of the corresponding first solenoid valve through a corresponding bundle tube. At the same time, the vent ends of all first solenoid valves are connected to the suction port of the air pump through the main pipe. The exhaust port of the air pump is connected to the pretreatment control system. The sample delivery end of each first solenoid valve is connected to a sampling bundle tube. Multiple sampling tubes are connected to the sample delivery end of the second solenoid valve through the sampling main pipe. The vent end of the second solenoid valve is connected to the pretreatment control system. The air inlet of the second solenoid valve is connected to the air inlet of the positive pressure pump. The air outlet of the positive pressure pump is connected to the sample inlet of the analysis unit. S2: Negative pressure exhaust pipe; The PLC module controls the connection between the air inlet and outlet of all first solenoid valves and starts the air pump to quickly pump the gas from multiple sampling points in the area to be tested through the corresponding number of samplers and bundle tubes to the pre-processing control system for processing, and then discharges the gas. S3: Channel switching; The PLC module controls the first solenoid valve to change from connecting the air inlet and the vent to connecting the air inlet and the sample delivery end, thereby disconnecting the bundle tube from the main pipeline. At the same time, it controls the second solenoid valve to connect the air inlet and the sample delivery end. S4: Push the sample under positive pressure to analysis unit 1 for testing, and switch to emptying state after the test is completed; The positive pressure air pump is started, and the gas sample collected by the sampler corresponding to the bundle tube is pressed into the analysis unit for analysis by the positive pressure air pump. After the analysis is completed, the air inlet and outlet of the second solenoid valve are connected, and the analyzed gas sample enters the pre-processing control system for processing and then is discharged.

Images