Mixed heat carrier generator for coal in-situ pyrolysis

Abstract

The utility model belongs to the technical field of coal in-situ pyrolysis, and particularly discloses a mixed heat carrier generator for coal in-situ pyrolysis. Comprising an inner wall, the upper portion of the inner wall is a cylinder, the lower portion of the inner wall is a hollow cone, a cover body is arranged in the top of the inner wall, a plurality of nozzles are arranged on the lower surface of the cover body, an ignition device is arranged below the cover body, and a plurality of through holes are formed in the hollow cone. Fuel is injected into the inner wall through the nozzle, a combustion reaction is triggered through the ignition device to generate a mixed heat carrier, the mixed heat carrier enters a coal seam through the through holes for in-situ pyrolysis, the coal seam pyrolysis device is directly installed in the coal seam during use, the heat carrier does not need to be transported, the cost is lower, and the energy utilization rate is higher.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal in-situ pyrolysis, and in particular relates to a mixed heat carrier generator used for coal in-situ pyrolysis. Background Art

[0002] In-situ pyrolysis of coal refers to the process of introducing heat into underground coal seams to directly heat them, and then extracting the generated coal tar and pyrolysis gas to the surface after the solid organic matter in the coal is cracked by heat. Through in-situ pyrolysis of coal, coal can be converted into low-carbon or carbon-free resources such as methane and hydrogen, and the semi-coke can be retained underground, which not only realizes the efficient and low-carbon utilization of coal, but also greatly extends the depth range of coal mobilization.

[0003] Defects and shortcomings of the existing technology:

[0004] In-situ pyrolysis of coal requires a large amount of energy input to heat the coal seam to the pyrolysis temperature range. The existing technology mainly heats the high-temperature medium and injects it into the coal seam through a pipeline, which has low energy utilization efficiency and high cost. In addition, in-situ pyrolysis of coal faces the problems of high ground stress and high heat requirement of the coal seam. Utility Model Content

[0005] The utility model aims to provide a mixed heat carrier generator for in-situ pyrolysis of coal, so as to solve the technical problems of high transportation cost of high-temperature medium, low energy utilization rate, large coal seam ground stress and high heat requirement in the existing in-situ pyrolysis process of coal.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] In the first aspect, the utility model provides a mixed heat carrier generator for in-situ pyrolysis of coal, comprising an inner wall, the upper portion of the inner wall is a cylinder, the lower portion is a hollow cone, a cover body is provided inside the top of the inner wall, the cover body is provided with a plurality of nozzles on the lower surface, an ignition device is provided under the cover body, and the hollow cone is provided with a plurality of through holes.

[0008] A further improvement of the utility model is that an outer wall is arranged outside the inner wall, and a gas distributor is arranged at one end of the outer wall away from the cover body.

[0009] A further improvement of the utility model is that a porous partition is provided in the middle of the cylinder, a combustion zone is formed between the porous partition and the cover body, and a mixing zone is formed between the porous partition and the hollow cone.

[0010] A further improvement of the utility model is that the gas distributor is disc-shaped.

[0011] A further improvement of the utility model is that a cooling water channel is provided in the inner wall.

[0012] A further improvement of the utility model is that a high-pressure gas buffer chamber is provided inside the inner wall, and the high-pressure gas buffer chamber is filled with an inert gas.

[0013] A further improvement of the utility model is that a central combustion-supporting agent nozzle is provided at the center of the cover body, a fuel nozzle is provided outside the central combustion-supporting agent nozzle, and a main combustion-supporting agent nozzle is provided outside the fuel nozzle.

[0014] A further improvement of the utility model is that the ratio of the diameter of the gas distributor to the outer diameter length of the outer wall is 1.5-2.

[0015] A further improvement of the utility model is that a temperature monitor is provided on the outside of the outer wall.

[0016] A further improvement of the utility model is that: the cooling water channel is a tortuous channel.

[0017] Compared with the prior art, the utility model has at least the following beneficial effects:

[0018] 1. The utility model injects fuel into the inner wall through a nozzle, triggers a combustion reaction through an ignition device to generate a mixed heat carrier, and the mixed heat carrier enters the coal seam through a through hole for in-situ pyrolysis. When in use, it is directly installed in the coal seam without the need to transport the heat carrier, which has lower costs and higher energy utilization.

[0019] 2. The utility model improves the overall pressure resistance of the device by providing a cooling water pipeline and a high-pressure gas buffer chamber.

[0020] 3. The utility model increases the diffusion speed of the heat carrier and improves the heating efficiency by setting a gas distributor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting 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 an improper limitation on the present invention. In the drawings:

[0022] Figure 1 This is a schematic diagram of the structure of a mixed heat carrier generator for in-situ pyrolysis of coal according to the utility model;

[0023] Figure 2 This is a structural schematic diagram of a cover body in a mixed heat carrier generator for in-situ pyrolysis of coal according to the utility model;

[0024] Figure 3 This is a diagram of the use of a mixed heat carrier generator for in-situ pyrolysis of coal according to the utility model;

[0025] In the figure: 1. outer wall; 2. cover body; 3. cooling water channel; 4. combustion-aiding agent nozzle; 5. fuel nozzle; 6. ignition device; 7. porous partition; 8. through hole; 9. mixing zone; 10. combustion zone; 11. main combustion-aiding agent nozzle; 12. fuel nozzle; 13. central combustion-aiding agent nozzle; 14. premixing zone; 15. upper boundary of coal seam; 16. coal seam; 17. lower boundary of coal seam; 18. injection well; 19. cooling water pipeline; 20. fuel pipeline; 21. combustion-aiding agent pipeline; 22. coal seam fissure; 23. temperature monitor; 24. mixed heat carrier generator; 25. production well; 26. high-pressure gas buffer chamber; 27. inner wall; 28. gas distributor. DETAILED DESCRIPTION

[0026] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0027] The following detailed descriptions are all exemplary descriptions, and are intended to provide further detailed descriptions of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0028] Example 1

[0029] A mixed heat carrier generator for in-situ pyrolysis of coal, such as Figure 1 As shown, it includes an outer wall 1, an inner wall 27 is arranged inside the outer wall 1, the upper part of the inner wall 27 is a cylinder, and the lower part is a hollow cone, the side wall and the bottom of the cone are provided with through holes 8, and the through holes 8 are used to discharge the mixed heat carrier, the outer diameter of the cone close to the cylinder is larger than the outer diameter of the side away from the cylinder, a cover body 2 is arranged inside the end of the cylinder away from the cone, a plurality of nozzles are arranged on the cover body 2, an ignition device 6 is arranged below the cover body 2, a porous partition plate 7 is arranged in the middle of the cylinder, a combustion zone 10 is arranged above the porous partition plate 7, and a mixing zone 9 is arranged below the porous partition plate 7, a high-pressure gas buffer chamber 26 is arranged inside the inner wall 27 outside the mixing zone 9, and a cooling water channel 3 is arranged inside the inner wall 27 outside the combustion zone 10.

[0030] Specifically, the cover body 2 has two structures. The first structure is that a plurality of nozzles are provided on the cover body 2, and the plurality of nozzles are used to provide fuel and combustion aid;

[0031] The second structure is Figure 2 As shown, a central combustion aid nozzle 13 is provided at the center of the cover body 2, a fuel nozzle 12 is provided outside the central combustion aid nozzle 13, a main combustion aid nozzle 11 is provided outside the fuel nozzle 12, and a premixing zone 14 is provided below the central combustion aid nozzle 13. Figure 2 The structure shown can premix the fuel with part of the combustion aid.

[0032] Specifically, the outer wall 1 is a circular tube, and a gas distributor 28 is provided at one end of the outer wall 1 close to the through hole 8. The gas distributor 28 is disc-shaped, and the ratio of the diameter of the gas distributor 28 to the outer diameter length of the outer wall 1 is 1.5 to 2. The gas distributor 28 is used to improve the dispersion of the mixed heat carrier entering the coal seam, increase the contact area between the high-temperature gas and the coal seam, and improve the heat transfer efficiency.

[0033] Specifically, the high-pressure gas buffer chamber 26 is filled with high-pressure inert gas, thereby improving the pressure resistance of the mixed heat carrier generator and adapting to the high-stress environment of the underground coal seam.

[0034] Specifically, the combustion reaction in the combustion zone 10 releases a large amount of heat and generates a high-temperature mixed thermal fluid, mainly high-temperature CO2, H2O, N2, etc. The temperature of the high-temperature mixed thermal fluid is greater than or equal to 600°C.

[0035] Specifically, the cooling water channel 3 is a tortuous channel, which can adapt to the high-pressure environment of the underground coal seam and increase the heat exchange area.

[0036] Specifically, the central oxidant nozzle 13 is used to connect the oxidant and the premixing zone 14, and the fuel nozzle 12 is used to connect the fuel and the premixing zone 14. The premixing zone 14 realizes the premixing of the fuel and the oxidant; the main oxidant nozzle 11 connects the fuel and the combustion zone 10 to realize the full combustion of the fuel.

[0037] Specifically, the combustion aid is oxygen or air, the pressure is adjusted according to the pore pressure of the coal seam so that the outlet pressure of the mixed heat carrier is greater than the pore pressure of the coal seam, and the fuel is gas fuel, liquid fuel, coalbed methane, mixed fuel or one or more of them; the cooling water temperature is room temperature, and the pressure range is adjusted according to the pore pressure range of the formation.

[0038] Example 2

[0039] A mixed heat carrier generator for in-situ pyrolysis of coal is structured in a coal seam, such as Figure 3 As shown, the injection well 18 and the production well 25 are vertically arranged above the lower boundary 17 of the coal seam, passing through the upper boundary 15 of the coal seam and the coal seam 16. A mixed heat carrier generator 24 is provided at the bottom of the injection well 12, and a fuel pipeline 20, a cooling water pipeline 19 and an oxidation-aiding agent pipeline 21 are provided in the injection well 18. The fuel pipeline 20 is connected to the fuel nozzle 5, the cooling water pipeline 19 is connected to the cooling water channel 3, and the oxidation-aiding agent pipeline 21 is respectively connected to the main oxidation-aiding agent nozzle 11 and the central oxidation-aiding agent nozzle 13. A temperature monitor 23 is provided on the outer side of the outer wall 1. The temperature of the high-temperature mixed hot fluid when entering the coal seam is monitored by the temperature monitor 23, so as to regulate the flow in the cooling water pipeline 19.

[0040] Example 3

[0041] A method for using a mixed heat carrier generator for in-situ pyrolysis of coal comprises the following steps: exploiting an injection well 18 and a production well 25, fracturing a coal seam to form a coal seam fissure 22; installing a mixed heat carrier generator at the bottom of the injection well 18, with the outlet of the mixed heat carrier generator extending deep into the coal seam; connecting a fuel, an oxidant pipeline and a cooling water pipeline; an ignition device 6 starts ignition, and a combustion reaction occurs in the mixed heat carrier generator; the generated high-temperature mixed thermal fluid enters the coal seam fissure 22 through the outlet to heat the coal seam 16; the high-temperature mixed thermal fluid drives the oil and gas resources generated by the coal, and the oil and gas resources are exploited through the production well 25; the pyrolysis gas is reused as fuel and enters the mixed heat carrier generator through the fuel pipeline.

[0042] Example 4

[0043] A method for using a mixed heat carrier generator for in-situ pyrolysis of coal comprises the following steps:

[0044] The injection well 18 and the production well 25 are exploited, and the coal seam is fractured to form coal seam fissures 23; a mixed heat carrier generator is installed at the bottom of the injection well 18, and the outlet of the mixed heat carrier generator is deep into the coal seam; the fuel, the combustion-supporting agent pipeline and the cooling water pipeline are connected; the fuel is water-coal slurry, and the combustion-supporting agent is air, and the two enter the combustion zone; the ignition device starts to ignite, and a combustion reaction occurs in the mixed heat carrier generator; the high-temperature mixed thermal fluid generated enters the coal seam fissures through the outlet to heat the coal seam; the high-temperature mixed thermal fluid drives the oil and gas resources generated by the coal, and is produced through the production well 25; the pyrolysis gas is reused as fuel and enters the mixed heat carrier generator through the fuel pipeline.

[0045] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the embodiments disclosed above are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the utility model should be included in the scope of protection of the claims of the utility model.

Claims

1. A mixed heat carrier generator for in-situ pyrolysis of coal, characterized in that: The invention comprises an inner wall (27), the upper part of the inner wall (27) is a cylinder, the lower part is a hollow cone, a cover body (2) is arranged inside the top of the inner wall (27), a plurality of nozzles are arranged on the lower surface of the cover body (2), an ignition device (6) is arranged below the cover body (2), and a plurality of through holes (8) are arranged on the hollow cone.

2. A mixed heat carrier generator for in-situ pyrolysis of coal according to claim 1, characterized in that: An outer wall (1) is provided on the outer side of the inner wall (27), and a gas distributor (28) is provided on the end of the outer wall (1) away from the cover body (2).

3. The mixed heat carrier generator for in-situ pyrolysis of coal according to claim 1, characterized in that: A porous partition (7) is provided in the middle of the cylinder; a combustion zone (10) is provided between the porous partition (7) and the cover (2); and a mixing zone (9) is provided between the porous partition (7) and the hollow cone.

4. The mixed heat carrier generator for in-situ pyrolysis of coal according to claim 1, characterized in that: A cooling water channel (3) is provided in the inner wall (27).

5. The mixed heat carrier generator for in-situ pyrolysis of coal according to claim 1, characterized in that: A high-pressure gas buffer chamber (26) is provided in the inner wall (27), and the high-pressure gas buffer chamber (26) is filled with an inert gas.

6. The mixed heat carrier generator for in-situ pyrolysis of coal according to claim 1, characterized in that: A central combustion-supporting agent nozzle (13) is provided at the center of the cover body (2), a fuel nozzle (12) is provided outside the central combustion-supporting agent nozzle (13), and a main combustion-supporting agent nozzle (11) is provided outside the fuel nozzle (12).

7. A mixed heat carrier generator for in-situ pyrolysis of coal according to claim 2, characterized in that: The gas distributor (28) is disc-shaped.

8. The mixed heat carrier generator for in-situ pyrolysis of coal according to claim 2, characterized in that: A temperature monitor (23) is provided on the outside of the outer wall.

9. A mixed heat carrier generator for in-situ pyrolysis of coal according to claim 4, characterized in that: The cooling water channel (3) is a tortuous channel.

10. The mixed heat carrier generator for in-situ pyrolysis of coal according to claim 7, characterized in that: The ratio of the diameter of the gas distributor (28) to the outer diameter length of the outer wall (1) is 1.5 to 2.

Images