Experimental system and method for simulating underground gasification conditions to detect gasification product composition

Abstract

The present invention belongs to the field of underground coal gasification, and provides a test system and method for detecting the components of gasification products under simulated underground gasification conditions. The system includes a gasifying agent preparation system, which is connected to a gasification furnace system through a preparation pipeline. The gasification furnace system is connected to a water tank of a gasification purification system through a gasification channel. The gasification purification system is connected to a gas detection system through a purification air outlet. The gas detection system detects the gas components and contents in the gas processed by the gas purification system to determine the gasification products. The whole set of devices not only has a simple structure and reasonable design, but also can detect the gasification components and contents of different types of coal by changing the type of coal burned in the gasification furnace, so as to determine which type of coal is more suitable for underground coal gasification, and determine its gasification conditions, and improve the components of CH4 and H2 in the gasification products.

Description

Technical Field

[0001] The invention belongs to the technical field of underground coal gasification, and in particular relates to a test system and method for simulating underground gasification conditions to detect the composition of gasification products. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Underground coal gasification (UCG) is an effective means of developing deep coal resources. It belongs to the technical category of clean and efficient development and utilization. Compared with traditional coal mining-surface gasification, it has obvious advantages in economy, safety, cleanliness, etc. Underground coal gasification (UCG) is a process of controlled combustion of coal underground to produce combustible gas through thermal and chemical effects on coal. The gas fuel can be used for power generation, hydrogen production or raw gas synthesis (such as synthetic natural gas and synthetic oil).

[0004] At a time when natural gas resources cannot fully meet the sharp increase in market demand and new energy has not yet replaced oil and gas to achieve low-cost large-scale supply, the key to high-quality development of the energy industry and solving energy and environmental problems is to strengthen the efficient and clean use of coal based on national conditions.

[0005] The underground coal gasification project requires huge investment. Therefore, before conducting field tests, it is necessary to explore the content and composition of gasification products based on gasification conditions and coal quality characteristics. This requires first building a test device in the laboratory to simulate underground coal gasification conditions and detect the composition of gasification products, simulating the process of underground coal gasification. At present, there is a lack of simulation test devices suitable for underground coal gasification processes, and the existing test devices have not been able to realistically simulate the gasification products and content of different types of coal under the same gasification conditions. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a test system and method for simulating underground gasification conditions to detect the composition of gasification products. The present invention mainly simulates on-site operations through a test device for detecting the composition of gasification products under coal underground gasification conditions, burns different types of coal under gasification conditions, detects the content and composition after gasification, determines the type of coal that is more suitable for underground coal gasification, and determines its gasification conditions to increase the CH4 and H2 components in the gasification products.

[0007] According to some embodiments, a first solution of the present invention provides a test system for simulating underground gasification conditions to detect gasification product components, using the following technical solutions:

[0008] A test system for simulating underground gasification conditions to detect the composition of gasification products, including a gasifying agent preparation system, the gasifying agent preparation system is connected to a gasifier system through a preparation pipeline, the gasifier system is connected to a water pool of a gas purification system through a gasification channel; the gas purification system is connected to a gas detection system through a purification outlet;

[0009] The gas detection system detects the gas composition and content in the gas processed by the gas purification system to determine the gasification product.

[0010] Furthermore, the gasifying agent preparation system includes a pressure bottle, and the pressure bottle is connected to the gasifier system through a preparation pipeline; a pressure sensor and a switch are sequentially arranged on the preparation pipeline.

[0011] Furthermore, the gasifier system includes a gasifier, the inlet end of the gasifier is connected to the preparation pipeline, a temperature sensor is fixed on the gasifier, and the outlet end of the gasifier extends into the water pool of the gas purification system through a gasification channel.

[0012] Further, the gas purification system comprises a water seal tank, a cooling and washing tank, a tar removal tank, a spray capture tank and a desulfurization tank which are connected in sequence;

[0013] The outlet end of the desulfurization tank is connected to the gas detection system through a gasification channel.

[0014] Furthermore, the gas detection system includes a gas monitor and a computer, and a purification outlet is provided between the gas detector and the desulfurization tank.

[0015] Furthermore, the system also includes a monitoring system, which is electrically connected to the pressure sensor, the temperature sensor and the gas monitor respectively to obtain corresponding monitoring data for display.

[0016] Furthermore, the desulfurization tank is also connected to the water pool through an exhaust pipe.

[0017] Furthermore, the temperature sensor is installed on the coal and the gasification channel of the gasifier, and the measured temperature is transmitted to the monitoring system through the temperature sensor.

[0018] Furthermore, the gasifier structure is a hollow wall type gasifier.

[0019] According to some embodiments, a second solution of the present invention provides an experimental method for simulating underground gasification conditions to detect the composition of gasification products, using the following technical solution:

[0020] The test method for detecting the composition of gasification products under simulated underground gasification conditions includes:

[0021] Increasing the oxygen concentration and adding steam into the pressure bottle to prepare the gasifying agent;

[0022] The obtained coal is placed in the gasifier in the order of gas coal, fat coal, anthracite and lignite, the gasification temperature is controlled, the gasifying agent is transported to the gasifier through the preparation pipeline, and the gasification is carried out in batches;

[0023] The gas produced by burning different types of coal in the gasifier will be used for cooling, dust removal, decoking, dehydration and desulfurization through water seal tank, cooling and washing tank, detarring tank, spray capture tank and desulfurization tank. The content and composition of impurity gas produced by gasification can be calculated by observing the reduction of purifier in the gas purification system.

[0024] The gas purified by the gas purification system is tested for useful gas composition and content by the gas detection system, and the content of impurities and available gas produced by gasification is compared to determine which type of coal is more suitable for underground coal gasification.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention mainly simulates on-site operation through a test device for detecting the composition of gasification products under underground coal gasification conditions, burns different types of coal under gasification conditions, detects the content and composition after gasification, determines the type of coal that is more suitable for underground coal gasification, and determines its gasification conditions to increase the CH4 and H2 components in the gasification products. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 It is a structural diagram of a test system for simulating underground gasification conditions and detecting gasification product components according to an embodiment of the present invention;

[0029] Figure 2 It is a schematic diagram of the principle of the underground coal gasification process according to an embodiment of the present invention;

[0030] In the figure:

[0031] 1-pressure bottle; 2-pressure sensor; 3-switch; 4-temperature sensor; 5-gas transmission hole; 6-gasifier; 7-water seal tank; 8-cooling washing tank; 9-tar removal tank; 10-spray capture tank; 11-desulfurization tank; 12-water tank; 13-exhaust pipe; 14-flow sensor; 15-purification outlet; 16-gas monitor; 17-computer; 18-automatic monitoring; 19-gasifier preparation system; 20-gasifier system; 21-gas purification system; 22-gas detection system; 23-monitoring system; 24-inlet hole; 25-auxiliary hole; 26-outlet hole; 27-overlying rock layer; 28-coal seam; 29-ash; 30-gasification channel; 31-air flow channel. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] It should be noted that the following detailed descriptions are all illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0034] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0035] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0036] Embodiment 1

[0037] like Figure 1 As shown, this embodiment provides a test system for simulating underground gasification conditions to detect gasification product components, including a gasifying agent preparation system, the gasifying agent preparation system is connected to a gasifier system through a preparation pipeline, the gasifier system is connected to a water pool of a gas purification system through a gasification channel; the gas purification system is connected to a gas detection system through a purification outlet;

[0038] The gas detection system detects the gas composition and content in the gas processed by the gas purification system to determine the gasification product.

[0039] The gasifying agent preparation system comprises a pressure bottle, which is connected to the gasifier system through a preparation pipeline; a pressure sensor and a switch are sequentially arranged on the preparation pipeline.

[0040] The gasifier system comprises a gasifier, the inlet end of the gasifier is connected to the preparation pipeline, a temperature sensor is fixed on the gasifier, and the outlet end of the gasifier extends into the water pool of the gas purification system through a gasification channel.

[0041] The gas purification system comprises a water seal tank, a cooling and washing tank, a tar removal tank, a spray capture tank and a desulfurization tank connected in sequence;

[0042] The outlet end of the desulfurization tank is connected to the gas detection system through a gasification channel.

[0043] Among them, separate flow sensors are arranged behind the cooling and washing tank, the spray capture tank and the desulfurization tank to measure the gas flow; one end of the outlet of the gasifier is connected to the purification channel for gas purification, and the other end is directly connected to the water pool for absorbing the residual gas in the gasifier, and each purification device is connected upward with a pipeline to collect the residual gas in the purification process for full reuse, and an air transfer hole is arranged on the purification channel near the entrance of the water seal tank.

[0044] The gas detection system comprises a gas monitor and a computer, and a purification gas outlet is arranged between the gas monitor and the desulfurization tank.

[0045] The system also includes a monitoring system, which is electrically connected to the pressure sensor, the temperature sensor and the gas monitor respectively to obtain corresponding monitoring data for display.

[0046] The desulfurization tank is also connected to the water pool through an exhaust pipe.

[0047] The temperature sensor is installed on the coal and gasification channel of the gasifier, and the measured temperature is transmitted to the monitoring system through the temperature sensor.

[0048] The gasifier structure is a hollow wall type gasifier.

[0049] like Figure 1 As shown, the present invention provides a schematic diagram of an underground coal gasification device Figure 1 , 1 pressure bottle; 2 pressure sensor; 3 switch; 4 temperature sensor; 5 gas transmission hole; 6 gasifier; 7 water seal tank; 8 cooling washing tank; 9 tar removal tank; 10 spray capture tank; 11 desulfurization tank; 12 water pool; 13 exhaust pipe; 14 flow sensor; 15 gas outlet; 16 gas monitor; 17 computer; 18 automatic monitoring; 19 gasification agent preparation system; 20 gasifier system; 21 gas purification system; 22 gas detection system; 23 monitoring system, etc. together constitute the experimental device for detecting the composition of gasification products under underground coal gasification conditions.

[0050] like Figure 2As shown, the present invention provides a schematic diagram of the underground coal gasification process principle Figure 2 , 24 air inlet; 25 auxiliary hole; 26 air outlet; 27 overlying rock layer; 28 coal seam; 29 ash; 30 gasification channel; 31 air flow channel; The principle of underground coal gasification process is to inject gasifying agent (air, oxygen or steam) into the air inlet, ignite it in the gasification channel, make the coal undergo thermochemical reaction to produce coal gas, and then lead it to the ground through the air outlet for use.

[0051] The test device for detecting the composition of gasification products under underground coal gasification conditions mainly includes six parts: gasification agent preparation system, gasification furnace system, gas purification system, gas outlet system, gas detection system and monitoring system.

[0052] This specific implementation case mainly simulates field operation through a test device for detecting the composition of gasification products under underground coal gasification conditions, burns different types of coal under gasification conditions, detects the content and composition after gasification, determines the type of coal that is more suitable for underground coal gasification, and determines its gasification conditions to increase the CH4 and H2 components in the gasification products. This device is not only simple in structure, but also reasonably designed and easy to use, and is a test device for simulating underground coal gasification conditions to detect the composition of gasification products.

[0053] Specifically, the gasification agent preparation system is composed of a steel cylinder filled with O2, air and steam, a pressure sensor is installed on the steel cylinder, and the pressure sensor will automatically open or close the switch according to the air pressure requirement in the pressure container, and the steel cylinder is connected to the gasifier by a pipeline (preparation pipeline). It can be understood that the steel cylinder here is a pressure cylinder.

[0054] More specifically, the gasifier preparation system increases the oxygen concentration and adds steam to the gasifier, which can change the carbon-oxygen balance into a carbon-oxygen-steam balance, thereby improving the thermal efficiency through waste heat, increasing the effective gas volume, and reducing the relative oxygen consumption of the gasifier.

[0055] The steel cylinder is a cylindrical steel container. The use of a cylindrical steel container can reduce the pressure of the gas inside on the outside and prevent the occurrence of explosions. The steel container has the advantages of light weight, high strength, good designability, and excellent processability.

[0056] The arrangement of the gasifier system and the gasification channel should ensure that the gasifier has good thermal characteristics to meet the requirements of gas production continuity and stability. A temperature sensor should be installed in the gasifier system. The temperature sensor is placed on the coal and the gasification channel. The measured temperature is transmitted to the monitoring system through the temperature sensor to record the temperature change.

[0057] The gasifier should be constructed according to the occurrence and geological conditions of the coal seam. The well type and the non-well type are common methods for building underground gasifiers. The non-well method is suitable for coal seams with simple geological conditions and can meet the needs of long-distance and large-scale gas extraction. The well method can make full use of existing mines and tunnels to build gasifiers under complex geological conditions. It has the advantages of flexibility and variability. For complex mining coal mines and local blocks, the well method is more effective. The gasifier structure is a hollow wall gasifier and a feather hole design. Its advantages are good seepage combustion gasification conditions and gasification reaction boundary conditions and excellent thermal characteristics.

[0058] Specifically, the gas purification system includes a water pool, a water seal tank, a cooling and washing tank, a detarring tank, a spray capture tank, a desulfurization tank, etc. The gas purification system passes the gas generated by the combustion of the gasifier through the gas purification system to detect the content and composition of the impurity gas generated by gasification.

[0059] The gas generated after combustion in the gasifier is used for cooling, dust removal, decoking, dehydration and desulfurization through a water seal tank, a cooling and washing tank, a detarring tank, a spray capture tank and a desulfurization tank. The content and composition of the impurity gas generated by gasification are calculated by observing the reduction in the purifier in the gas purification system.

[0060] Specifically, the gas outlet system is to purify the gas generated by the combustion of different types of coal and gasification agent and then transport it to the gas detection system to detect and analyze the composition and content. The gas outlet system is mainly composed of a gas detection system, which detects the composition and content of the useful gas after the gas purification system, so as to determine which type of coal is more suitable for underground coal gasification, determine its gasification conditions, and increase the CH4 and H2 components in the gasification product.

[0061] Specifically, the monitoring system is used to monitor the operating state of the gasifier, the injection and gas production of the gasifying agent, and the temperature change in the gasification channel.

[0062] More specifically, the monitoring system is based on an automatic control system, which maintains the gas pressure in the pressure vessel between the minimum and maximum set values ​​during the entire experiment. It will be used to monitor the temperature, pressure, and gasification products during the gasification process. The monitoring system consists of multiple screens that can be switched between. The monitoring system is based on an automatic control system, with control being the core function, and monitoring to monitor the operating status of the gasifier, the injection and gas production of the gasifying agent, the temperature changes in the gasification channel, and the solenoid valve and pressure gauge, etc.

[0063] The gasifier preparation system cylinder in the underground coal gasification device is connected to the gasifier by a pipeline. The cylinder is a cylindrical steel container with the advantages of light weight, high strength, good designability and excellent processability.

[0064] The gasifiers are divided into shaft-type and shaftless-type gasifiers. The shaftless-type method is suitable for coal seams with simple geological conditions and can meet the needs of long-distance, large-scale gas extraction; while the shaft-type method can make full use of existing mines and tunnels to build gasifiers under complex geological conditions. It has the advantages of flexibility and variability. For complex mining coal mines and local blocks, the shaft-type method is more effective.

[0065] The coal required for this implementation case is mainly gas coal, bituminous coal, lean coal and other types, but not limited to these.

[0066] The structure of the gasifier is a hollow wall gasifier, which has the advantages of good percolation combustion gasification conditions, good gasification reaction boundary conditions and excellent thermal characteristics.

[0067] Temperature sensors should be installed in the gasifier system. The temperature sensors are placed on the coal and gasification channels. The measured temperature is transmitted to the monitoring system through the temperature sensors to record temperature changes.

[0068] The monitoring system is based on an automatic control system. Control is the core function. Monitoring is to monitor the operating status of the gasifier, the injection and gas production of the gasifier, the temperature changes in the gasification channel, and the solenoid valve and pressure gauge.

[0069] The above test device not only realizes underground coal gasification in the laboratory, but also determines which type of coal mine is more suitable for underground coal gasification by burning different types of coal, determines its gasification conditions, and increases the CH4 and H2 components in the gasification products. Laboratory tests can control test variables and eliminate the influence of irrelevant variables, laying a solid foundation for subsequent field operations.

[0070] Embodiment 2

[0071] This embodiment provides a test method for simulating underground gasification conditions to detect gasification product components, including:

[0072] Increasing the oxygen concentration and adding steam into the pressure bottle to prepare the gasifying agent;

[0073] The obtained coal is placed in the gasifier in the order of gas coal, fat coal, anthracite and lignite, the gasification temperature is controlled, the gasifying agent is transported to the gasifier through the preparation pipeline, and the gasification is carried out in batches;

[0074] The gas produced by burning different types of coal in the gasifier will be used for cooling, dust removal, decoking, dehydration and desulfurization through water seal tank, cooling and washing tank, detarring tank, spray capture tank and desulfurization tank. The content and composition of impurity gas produced by gasification can be calculated by observing the reduction of purifier in the gas purification system.

[0075] The gas purified by the gas purification system is tested for useful gas composition and content by the gas detection system, and the content of impurities and available gas produced by gasification is compared to determine which type of coal is more suitable for underground coal gasification.

[0076] It can be ignored that we did not examine the effect of changing the local pressure due to the removal of mass in the experimental gasification. Since the investment amount of field tests is huge and the conditions are more demanding, various abnormal situations are likely to occur. Therefore, the present invention adopts indoor tests because laboratory tests do not have to consider similar effects.

[0077] In order to determine the type of coal that is more suitable for underground coal gasification, it is necessary to select coal from different coal mines and different types for laboratory tests. This implementation case selected 20 kg each of gas coal, fat coal, anthracite and lignite for testing. The main reference parameters are: the thickness of the coal seam is generally required to be greater than 2m; the suitable inclination angle of the coal seam for underground coal gasification is 0°~70°; the angle change of the gasified coal seam is <2°; the distance between the gasified coal seam and the fault is >200m; the distance between the two main faults is at least 1000m; the moisture content of the coal seam is <15%, the ash content is <50%, the sulfur content is <1%, the direct roof thickness is >15m, the coal seam permeability is (50~150)×10-3μm2, and the coal resources are >80Mt.

[0078] First, by increasing the oxygen concentration and adding steam to the pressure bottle, the carbon-oxygen balance can be changed into a carbon-oxygen-steam balance, which can not only improve the thermal efficiency through waste heat, but also increase the effective gas volume and reduce the relative oxygen consumption of the gasifier;

[0079] The obtained coal is placed in the gasifier in the order of gas coal, fat coal, anthracite, lignite, etc., the gasification temperature is controlled, the gasifying agent is transported to the gasifier through a pipeline, and then gasification is carried out in batches.

[0080] Underground coal gasification produces gas by burning different types of coal in the gasifier. The gas passes through water seal tanks, cooling and washing tanks, detarring tanks, spray capture tanks and desulfurization tanks for cooling, dust removal, decoking, dehydration and desulfurization. The content and composition of impurity gas produced by gasification are calculated by observing the reduction of purifiers in the gas purification system.

[0081] The gas purified by the gas purification system is tested for useful gas composition and content through the gas outlet system, and the impurities produced by gasification and the content of available gas are compared to determine which type of coal is more suitable for underground coal gasification, and its gasification conditions are determined to increase the CH4 and H2 components in the gasification products.

[0082] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A test method for detecting the composition of gasification products by simulating underground gasification conditions, characterized in that: include: Increasing the oxygen concentration and adding steam into the pressure bottle to prepare the gasifying agent; Coal from different coal mines and different types of coal are placed in the gasifier, the gasification temperature is controlled, the gasifying agent is transported to the gasifier through the preparation pipeline, and gasification is carried out in batches; The gas produced by burning different types of coal in the gasifier is cooled, dusted, decoked, dehydrated and desulfurized through water seal tanks, cooling and washing tanks, detarring tanks, spray trapping tanks and desulfurization tanks. The content and composition of impurity gas produced by gasification are calculated by observing the reduction of purifier in the gas purification system. The gas purified by the gas purification system is tested for useful gas composition and content by the gas detection system, and the content of impurities and available gas produced by gasification is compared to determine which type of coal is more suitable for underground coal gasification.

2. The test method for detecting the composition of gasification products under simulated underground gasification conditions according to claim 1, characterized in that: The test method for detecting the composition of gasification products under simulated underground gasification conditions is implemented by using a test system for detecting the composition of gasification products under simulated underground gasification conditions. The test system for detecting the composition of gasification products under simulated underground gasification conditions includes a gasifying agent preparation system, the gasifying agent preparation system is connected to a gasifier system through a preparation pipeline, the gasifier system is connected to a water pool of a gas purification system through a gasification channel; the gas purification system is connected to a gas detection system through a purification outlet; The gas detection system detects the gas composition and content in the gas processed by the gas purification system to determine the gasification product.

3. The test method for detecting the composition of gasification products under simulated underground gasification conditions according to claim 2, characterized in that: The gasifying agent preparation system comprises a pressure bottle, which is connected to the gasifier system through a preparation pipeline; a pressure sensor and a switch are sequentially arranged on the preparation pipeline.

4. The test method for detecting the composition of gasification products under simulated underground gasification conditions according to claim 3, characterized in that: The gasifier system comprises a gasifier, the inlet end of the gasifier is connected to the preparation pipeline, a temperature sensor is fixed on the gasifier, and the outlet end of the gasifier extends into the water pool of the gas purification system through a gasification channel.

5. The test method for detecting the composition of gasification products under simulated underground gasification conditions according to claim 4, characterized in that: The gas purification system comprises a water seal tank, a cooling and washing tank, a tar removal tank, a spray capture tank and a desulfurization tank connected in sequence; The outlet end of the desulfurization tank is connected to the gas detection system through a gasification channel.

6. The test method for detecting the composition of gasification products under simulated underground gasification conditions according to claim 5, characterized in that: The gas detection system comprises a gas monitor and a computer, and a purification outlet is arranged between the gas monitor and the desulfurization tank.

7. The test method for detecting gasification product composition under simulated underground gasification conditions according to claim 6, characterized in that: It also includes a monitoring system, which is electrically connected to the pressure sensor, the temperature sensor and the gas monitor respectively to obtain corresponding monitoring data for display.

8. The test method for detecting the composition of gasification products under simulated underground gasification conditions according to claim 5, characterized in that: The desulfurization tank is also connected to the water pool through an exhaust pipe.

9. The test method for detecting gasification product composition under simulated underground gasification conditions according to claim 4, characterized in that: The temperature sensor is installed on the gasification channel of the gasifier, and the measured temperature is transmitted to the monitoring system through the temperature sensor.

10. The test method for detecting gasification product composition under simulated underground gasification conditions according to claim 4, characterized in that: The gasifier structure is a hollow wall type gasifier.

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