Coal underground gasification product heat energy recovery device

Abstract

The invention discloses a coal underground gasification product heat energy recovery device, and belongs to the field of coal underground gasification. The device comprises a recycling box and a contact pipe which are arranged on the surface of a breather pipe, the contact pipe is arranged on the surface of the breather pipe in a sleeving mode, a spiral guide groove is formed in the surface of the breather pipe, and a spiral guide ring is arranged on the inner wall of the contact pipe to guide airflow introduced into the contact pipe to make full contact with the breather pipe. Heat exchange between airflow in the contact pipe and gasified product airflow is realized; the airflow in the contact pipe flows into the layering cavity after flowing, the airflow with different temperatures can stay in different areas in the layering cavity, and a cooling assembly is arranged at the bottom of the recycling box, so that the airflow with relatively low temperature quickly flows to and stays at the bottom of the layering cavity; and then through recycling pipes with different heights, airflow with different temperatures is guided to flow out of the recycling box, the recycling pipes are connected with different heat energy utilization mechanisms, recycling of airflow with different temperatures can be achieved, and then gradient recycling of heat energy of underground coal gasification products is achieved.

Description

Technical Field

[0001] This invention relates to the field of underground coal gasification, and in particular to a device for recovering heat energy from underground coal gasification products. Background Technology

[0002] Coal underground gasification is an innovative coal mining technology that converts underground coal into combustible gas through a controlled thermochemical reaction. Generally, a gasifying agent (such as oxygen, water vapor, or oxygen-enriched air) is injected into the coal seam to initiate pyrolysis, oxidation, and reduction reactions of the coal in situ underground, generating combustible gas mainly composed of carbon monoxide, hydrogen, and methane. When the gasifying agent comes into contact with the coal, a violent oxidation reaction occurs, releasing a large amount of heat. In order to utilize energy efficiently, the sensible heat of the syngas is usually converted into steam or electricity through devices such as waste heat boilers and heat exchangers.

[0003] Current technologies mainly recover waste heat by laying fixed heat exchange tubes on the surface or by using a staged heat exchange system. Fixed heat exchange devices generally recover and utilize heat directly. However, due to the different reaction zones, there is usually a gradient difference in the heat of underground coal gasification products. Fixed heat exchange devices cannot change the use of the recovered heat according to the product heat, which has certain limitations. Although staged heat exchange systems introduce high-temperature gas into power generation and reinject medium-temperature gas underground, they rely on multi-stage heat exchangers and complex airflow distribution devices. However, some low-temperature gas heat energy is still wasted, which limits the improvement of overall thermal efficiency.

[0004] In summary, existing underground coal gasification product heat recovery devices suffer from low efficiency in heat gradient utilization and incomplete utilization of low-temperature waste heat. Summary of the Invention

[0005] This invention provides a thermal energy recovery device for underground coal gasification products, which can solve the problems of low thermal energy gradient utilization efficiency and incomplete utilization of low-temperature waste heat in existing underground coal gasification product thermal energy recovery devices.

[0006] A coal underground gasification product heat energy recovery device includes a vent pipe for conveying gasification products and a recovery box, wherein a recovery mechanism is provided between the vent pipe and the recovery box, and the recovery mechanism includes: A contact tube is fixedly installed on the surface of the recycling bin. The contact tube is sleeved on the surface of the vent pipe. A guide groove is opened on the surface of the vent pipe. A guide ring is fixedly connected inside the contact tube. Both the guide groove and the guide ring are spiral-shaped. The recycling bin has a layered cavity inside, the contact pipe is connected to the layered cavity, and the vent pipe passes through the layered cavity and extends to the surface of the recycling bin. A cooling assembly is provided at the bottom of the recycling bin. A first recycling pipe, a second recycling pipe, and a third recycling pipe are fixedly connected inside the recycling bin, and the first recycling pipe, the second recycling pipe, and the third recycling pipe are arranged at intervals from top to bottom.

[0007] Optionally, the first recycling pipe is connected to the power assembly, the second recycling pipe extends to the underground reaction reduction zone, and the third recycling pipe is in contact with the underfloor heating assembly.

[0008] Optionally, the vent pipe has a spiral groove inside, which corresponds to the guide groove, and the distance between the two is greater than zero.

[0009] Optionally, an arc-shaped block is fixedly connected inside the contact tube, the opening of the arc-shaped block corresponds to the end of the guide ring, and an air inlet groove is formed on the surface of the contact tube, with the edge of the air inlet groove located between the arc-shaped block and the contact tube.

[0010] Optionally, the cooling assembly includes a cooling pipe fixedly disposed inside the recycling bin, the end of which is connected to a water pump.

[0011] Optionally, the cooling pipe includes two internal pipes and an external pipe. The two internal pipes are fixedly connected to both ends of the external pipe. The internal pipes are fixedly installed in a continuous S-shape inside the recovery box, and the two internal pipes are symmetrically arranged. The external pipe is wound around the surface of the injection wellhead of the underground coal gasification.

[0012] Optionally, the other end of the second recovery pipe is connected to the air inlet slot.

[0013] Optionally, both the second and third recycling tubes are fixedly installed inside the recycling bin via an adjustment assembly, which is used to change the position of the ends of the second and third recycling tubes inside the recycling bin.

[0014] Optionally, the adjustment assembly includes an adjustment ring rotatably disposed inside the recycling bin, a protruding ring fixedly connected to the surface of the adjustment ring, the second recycling tube and the third recycling tube passing through the protruding ring, and the other ends of the second recycling tube and the third recycling tube passing through the end of the adjustment ring and fixed to the adjustment ring; a limiting assembly for limiting the position is provided between the protruding ring and the recycling bin.

[0015] Optionally, the limiting component includes a limiting ring slidably disposed on the surface of the protruding ring, a locking tooth fixedly connected to the surface of the limiting ring, a limiting groove formed on the surface of the recycling bin, a plurality of limiting teeth fixedly connected inside the limiting groove, the plurality of limiting teeth arranged in a ring array inside the limiting groove, the projected edge of the locking tooth facing the limiting groove coincides with the edge of the adjacent limiting tooth, and a connecting spring fixedly connected between the protruding ring and the limiting ring.

[0016] This invention provides a coal underground gasification product heat energy recovery device, including a recovery box and a contact pipe disposed on the surface of a ventilation pipe. The contact pipe is sleeved on the surface of the ventilation pipe, and a spiral guide groove is formed on the surface of the ventilation pipe. A spiral guide ring is provided on the inner wall of the contact pipe to guide the airflow entering the contact pipe to fully contact the ventilation pipe, thereby realizing heat exchange between the airflow inside the contact pipe and the gasification product airflow. After the airflow flows through the contact pipe, it enters the stratification chamber. Airflows of different temperatures will stay in different areas inside the stratification chamber, and a cooling component is provided at the bottom of the recovery box to allow the relatively low-temperature airflow to flow quickly to and stay at the bottom of the stratification chamber. Then, through recovery pipes of different heights, the airflows of different temperatures are guided out of the recovery box. By connecting the recovery pipes to different heat energy utilization mechanisms, the reuse of airflows of different temperatures can be realized, thereby achieving gradient recovery of the heat energy of coal underground gasification products. Attached Figure Description

[0017] Figure 1 This invention provides a schematic diagram of a thermal energy recovery device for underground coal gasification products. Figure 2 A three-dimensional view of the internal tube provided by the present invention; Figure 3 A three-dimensional cross-sectional view of the contact tube provided by the present invention; Figure 4 A three-dimensional structural cross-sectional view of the air intake groove provided by the present invention; Figure 5 This is an exploded three-dimensional view of the adjustment component provided by the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Vent pipe; 2. Recycling bin; 31. Contact tube; 32. Guide groove; 33. Guide ring; 34. Layered cavity; 35. First recovery tube; 36. Second recovery tube; 37. Third recovery tube; 41. Spiral groove; 42. Arc-shaped block; 43. Air inlet groove; 44. Internal tube; 45. External tube; 51. Adjusting ring; 52. Protruding ring; 53. Limiting ring; 54. Locking tooth; 55. Limiting tooth; 56. Connecting spring. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0020] like Figures 1 to 5 As shown in the figure, an embodiment of the present invention provides a coal underground gasification product heat energy recovery device, including a gas pipe 1 for conveying gasification products and a recovery box 2 for recovering heat energy. A recovery mechanism is provided between the gas pipe 1 and the recovery box 2, and the recovery mechanism includes: A contact tube 31 is fixedly installed on the surface of the recycling bin 2. The contact tube 31 is sleeved on the surface of the ventilation tube 1. A guide groove 32 is opened on the surface of the ventilation tube 1. A guide ring 33 is fixedly connected inside the contact tube 31. Both the guide groove 32 and the guide ring 33 are spiral. The recycling bin 2 has a layered cavity 34 inside, and the contact pipe 31 communicates with the layered cavity 34. The vent pipe 1 passes through the layered cavity 34 and extends to the surface of the recycling bin 2. A cooling component for reducing the temperature at the bottom of the recycling bin 2 is provided. A first recycling pipe 35, a second recycling pipe 36, and a third recycling pipe 37 are fixedly connected inside the recycling bin 2, and the first recycling pipe 35, the second recycling pipe 36, and the third recycling pipe 37 are spaced apart from top to bottom on the surface of the recycling bin 2. The first recycling pipe 35 is connected to the power component, the second recycling pipe 36 extends to the underground reaction reduction zone, and the third recycling pipe 37 is in contact with the underfloor heating component. In summary, the coal underground gasification product heat energy recovery device provided by this embodiment of the invention includes a recovery box 2 and a contact pipe 31 disposed on the surface of a ventilation pipe 1. The contact pipe 31 is sleeved on the surface of the ventilation pipe 1, and a spiral guide groove 32 is opened on the surface of the ventilation pipe 1. A spiral guide ring 33 is provided on the inner wall of the contact pipe 31 to guide the airflow entering the contact pipe 31 to fully contact the ventilation pipe 1, thereby realizing heat exchange between the airflow inside the contact pipe 31 and the gasification product airflow. After the airflow inside the contact pipe 31 flows, it enters the layered cavity 34. Airflows of different temperatures will stay in different areas inside the layered cavity 34. A cooling component is provided at the bottom of the recovery box 2, so that the relatively low-temperature airflow flows quickly to and stays at the bottom of the layered cavity 34. Then, through recovery pipes of different heights, the airflows of different temperatures are guided out of the recovery box 2. By connecting the recovery pipes to different heat energy utilization mechanisms, the reuse of airflows of different temperatures can be realized, thereby realizing the gradient recovery of the heat energy of coal underground gasification products. The airflow stratification inside the stratification chamber 34 is achieved based on the density difference of airflows at different temperatures. The airflow with higher temperature has a lower density and will naturally float upward and gather in the upper region of the stratification chamber 34. The airflow with medium temperature will be suspended in the middle of the stratification chamber 34. The airflow with relatively lower temperature has a higher density and, under the action of the cooling component, can quickly flow to and remain stably at the bottom of the stratification chamber 34. The cooling component further widens the temperature difference between the bottom and the upper middle region of the stratification chamber 34 by continuously reducing the temperature at the bottom of the recovery box 2, thereby enhancing the airflow stratification effect and making the boundaries of airflows in different temperature ranges clearer, creating favorable conditions for subsequent gradient recovery. In some specific implementations, a spiral groove 41 is provided inside the ventilation pipe 1. The spiral groove 41 corresponds to the guide groove 32, and the distance between the two is greater than zero. The spiral groove 41 inside the ventilation pipe 1 can guide the underground coal gasification products to flow along a specific channel in the ventilation pipe 1, and the distance between the gasification products and the guide groove 32 ensures heat transfer efficiency. In some specific implementations, an arc-shaped block 42 is fixedly connected inside the contact tube 31, the opening of the arc-shaped block 42 corresponds to the end of the guide ring 33, and an air inlet groove 43 is provided on the surface of the contact tube 31, with the edge of the air inlet groove 43 located between the arc-shaped block 42 and the contact tube 31. In some specific implementations, the cooling assembly includes a cooling pipe fixedly installed inside the recovery tank 2. The end of the cooling pipe is connected to a water pump. The cooling pipe includes two internal pipes 44 and an external pipe 45. The two internal pipes 44 are fixedly connected to both ends of the external pipe 45. The internal pipes 44 are fixedly installed in a continuous S-shape inside the recovery tank 2, and the two internal pipes 44 are symmetrically arranged. The external pipe 45 is wound around the surface of the injection wellhead of the underground coal gasification. In some specific implementation schemes, the other end of the second recovery pipe 36 is connected to the air inlet trough 43; that is, the second recovery pipe 36 is discharged from the recovery box 2, flows through the underground reaction reduction zone in the underground coal gasification process under the action of the pipeline, transfers heat, ensures the temperature of the reaction reduction zone, and then flows out and re-enters the contact pipe 31 through the air inlet trough 43 to realize airflow circulation, which not only improves the thermal energy utilization efficiency, but also reduces the consumption of external gas source, forming a closed-loop system for energy recycling. The first recovery pipe 35, the second recovery pipe 36 and the third recovery pipe 37 are all fixedly connected with regulating valves, which can control the flow rate of gas inside the first recovery pipe 35, the second recovery pipe 36 and the third recovery pipe 37; In some specific implementations, the underfloor heating component includes pipes filled with water, which are buried underground. A third recovery pipe 37 is attached to the surface of the pipes to achieve heat exchange and maintain the temperature of the underfloor heating. The underfloor heating component achieves efficient heat exchange by attaching the buried water-filled pipes to the surface of the third recovery pipe 37 to maintain the temperature stability of the underfloor heating system. This not only makes full use of waste heat to improve energy efficiency, but also achieves uniform indoor temperature distribution through water circulation and heat conduction, avoiding the problem of local overheating in traditional heating equipment. It should be noted that the power generation component converts the thermal energy or internal energy of the high-temperature gas into electrical energy, and optimizes the energy conversion through different technical paths. There are multiple combinations, such as the combination and usage method proposed in the patent titled: Coal Underground Gasification Fluid Waste Heat and Gasification Site Cogeneration Device and Method (Patent Publication No.: CN118407822A), which can convert the high-temperature gas inside the first recovery pipe 35 into electrical energy. In some specific implementations, the second recycling tube 36 and the third recycling tube 37 are both fixedly installed inside the recycling bin 2 by an adjustment component, which is used to change the position of the ends of the second recycling tube 36 and the third recycling tube 37 inside the recycling bin 2; In a further embodiment, the adjusting assembly includes an adjusting ring 51 rotatably disposed inside the recycling bin 2, a protruding ring 52 fixedly connected to the surface of the adjusting ring 51, the second recycling tube 36 and the third recycling tube 37 passing through the protruding ring 52, and the other ends of the second recycling tube 36 and the third recycling tube 37 passing through the end of the adjusting ring 51 and fixed to the adjusting ring 51; a limiting assembly for limiting the position is provided between the protruding ring 52 and the recycling bin 2; In a further embodiment, the limiting component includes a limiting ring 53 slidably disposed on the surface of the protruding ring 52, a locking tooth 54 fixedly connected to the surface of the limiting ring 53, a limiting groove is formed on the surface of the recycling bin 2, and a plurality of limiting teeth 55 are fixedly connected inside the limiting groove. The plurality of limiting teeth 55 are arranged in a ring array inside the limiting groove, and the projected edge of the locking tooth 54 facing the limiting groove coincides with the edge of the adjacent limiting tooth 55. In a further embodiment, a plurality of sliding shafts are fixedly connected to the surface of the limiting ring 53, and a plurality of sliding grooves are formed on the surface of the protruding ring 52, wherein the sliding shafts are adapted to the sliding grooves; a connecting spring 56 is fixedly connected between the protruding ring 52 and the limiting ring 53. When it is necessary to change the position of the ends of the second recycling pipe 36 and the third recycling pipe 37 inside the recycling box 2, the limiting ring 53 needs to be slid first to disengage the limiting tooth 55 and the locking tooth 54. Then, the limiting ring 53 is rotated. The rotation of the limiting ring 53, under the action of the sliding shaft and the sliding groove, drives the protruding ring 52 to rotate, which in turn drives the adjusting ring 51 to rotate, causing the ends of the second recycling pipe 36 and the third recycling pipe 37 to change their position inside the recycling box 2. After the position is appropriate, the limiting ring 53 is released. The limiting ring 53 will slide under the action of the connecting spring 56, so that the locking tooth 54 and the limiting tooth 55 contact each other, restricting the rotation of the limiting ring 53. Working principle of the invention: In use, gas is introduced into the contact pipe 31 through the air inlet 43. When the underground coal gasification products flow from the ventilation pipe 1 to a specific location, the gas inside the contact pipe 31 exchanges heat with the gas inside the ventilation pipe 1. After the gas inside the contact pipe 31 flows out of the contact pipe 31, it enters the layered cavity 34. Under the action of the cooling component, the gas with lower temperature gathers at the bottom of the layered cavity 34, and the gas at different heights is discharged at different locations.

[0021] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A device for recovering heat energy from underground coal gasification products, characterized in that, It includes a vent pipe (1) for conveying gasification products and a recovery box (2), and a recovery mechanism is provided between the vent pipe (1) and the recovery box (2), the recovery mechanism including: A contact tube (31) is fixedly installed on the surface of the recycling bin (2). The contact tube (31) is sleeved on the surface of the ventilation pipe (1). A guide groove (32) is opened on the surface of the ventilation pipe (1). A guide ring (33) is fixedly connected inside the contact tube (31). Both the guide groove and the guide ring (33) are spiral. The recycling bin (2) has a layered cavity (34) inside, the contact pipe (31) is connected to the layered cavity (34), the vent pipe (1) passes through the layered cavity (34) and extends to the surface of the recycling bin (2); a cooling assembly is provided at the bottom of the recycling bin (2), and a first recycling pipe (35), a second recycling pipe (36) and a third recycling pipe (37) are fixedly connected inside the recycling bin (2), and the first recycling pipe (35), the second recycling pipe (36) and the third recycling pipe (37) are arranged at intervals from top to bottom.

2. The coal underground gasification product heat recovery device as described in claim 1, characterized in that, The first recycling pipe (35) is connected to the power component, the second recycling pipe (36) extends to the underground reaction reduction zone, and the third recycling pipe (37) is in contact with the floor heating component.

3. The coal underground gasification product heat recovery device as described in claim 1, characterized in that, The ventilation pipe (1) has a spiral groove (41) inside, which corresponds to the guide groove (32), and the distance between them is greater than zero.

4. The coal underground gasification product heat energy recovery device as described in claim 1, characterized in that, An arc-shaped block (42) is fixedly connected inside the contact tube (31). The opening of the arc-shaped block (42) corresponds to the end of the guide ring (33). An air inlet groove (43) is opened on the surface of the contact tube (31). The edge of the air inlet groove (43) is located between the arc-shaped block (42) and the contact tube (31).

5. The coal underground gasification product heat recovery device as described in claim 1, characterized in that, The cooling assembly includes a cooling pipe fixedly installed inside the recycling bin (2), the end of which is connected to a water pump.

6. The coal underground gasification product heat recovery device as described in claim 5, characterized in that, The cooling pipe includes two internal pipes (44) and an external pipe (45). The two internal pipes (44) are fixedly connected to the two ends of the external pipe (45). The internal pipes (44) are fixedly arranged in a continuous S-shape inside the recovery box (2), and the two internal pipes (44) are arranged symmetrically. The external pipe (45) is wrapped around the surface of the injection wellhead of the underground coal gasification.

7. The coal underground gasification product heat recovery device as described in claim 1, characterized in that, The other end of the second recovery pipe (36) is connected to the air inlet slot (43).

8. The coal underground gasification product heat recovery device as described in claim 1, characterized in that, The second recycling tube (36) and the third recycling tube (37) are both fixedly installed inside the recycling box (2) by an adjustment component, which is used to change the position of the ends of the second recycling tube (36) and the third recycling tube (37) inside the recycling box (2).

9. A coal underground gasification product heat recovery device as described in claim 8, characterized in that, The adjustment assembly includes an adjustment ring (51) rotatably disposed inside the recycling bin (2). A protruding ring (52) is fixedly connected to the surface of the adjustment ring (51). The second recycling tube (36) and the third recycling tube (37) pass through the protruding ring (52), and the other ends of the second recycling tube (36) and the third recycling tube (37) pass through the end of the adjustment ring (51) and are fixed to the adjustment ring (51). A limiting assembly for limiting the position is provided between the protruding ring (52) and the recycling bin (2).

10. A coal underground gasification product heat recovery device as described in claim 9, characterized in that, The limiting component includes a limiting ring (53) slidably disposed on the surface of the protruding ring (52), a locking tooth (54) fixedly connected to the surface of the limiting ring (53), a limiting groove is opened on the surface of the recycling bin (2), a plurality of limiting teeth (55) are fixedly connected inside the limiting groove, the plurality of limiting teeth (55) are arranged in a ring array inside the limiting groove, the projection edge of the locking tooth (54) facing the limiting groove coincides with the edge of the adjacent limiting tooth (55), and a connecting spring (56) is fixedly connected between the protruding ring (52) and the limiting ring (53).

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