A system and method for in-situ pyrolysis of oil-rich coal using rock as a heat carrier
By using rocks as a heat carrier and combining wind-solar hybrid new energy sources with thermal power generation, oil-rich coal seams are indirectly heated, solving the problems of uneven heating and high cost in existing technologies. This achieves large-scale, uniform, and efficient in-situ pyrolysis of oil-rich coal, reducing system operating costs and carbon emissions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2025-07-01
- Publication Date
- 2026-07-03
AI Technical Summary
Existing in-situ pyrolysis technology for oil-rich coal suffers from problems such as uneven heating, limited range, high cost, and significant safety risks, making it difficult to achieve large-scale, uniform, and cost-effective heating.
Using rocks as the heat carrier, the overlying and underlying rock strata are electrically heated through a combination of wind-solar hybrid power generation and thermal power generation. The oil-rich coal seam is indirectly heated by the heat conduction and radiation of the rock strata themselves, and fine-tuning is achieved through temperature monitoring wells. Combined with high-temperature phase change materials and supercritical CO2 fracturing to form a fracture network, uniform heating of the coal seam is realized.
It has enabled large-scale uniform heating of oil-rich coal seams, reduced system operating costs and carbon emissions, extended the lifespan of the heating system, and improved the quality of oil and gas products and the efficiency of renewable energy utilization.
Smart Images
Figure CN120592600B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of energy technology and relates to a pyrolysis system and method for oil-rich coal, particularly to an in-situ pyrolysis system and method for oil-rich coal using rock as a heat carrier. Background Technology
[0002] Coal with a tar yield of 7–12% is defined as oil-rich coal. In-situ pyrolysis of oil-rich coal, a revolutionary technology proposed in recent years, provides a large-scale oil and gas supply route by pyrolyzing oil-rich coal in situ and extracting oil and gas products.
[0003] Common in-situ heating methods include electric heating, convection heating, radiation heating, and chemical reaction heating. Conduction heating suffers from uneven heating, with excessively high temperatures near the heater and insufficient temperatures further away, resulting in significant resource waste. Convection heating's pyrolysis efficiency heavily relies on formation permeability, and the low permeability of coal seams limits the heating range. Radiation heating, due to the rapid attenuation of electromagnetic wave energy underground, has a limited heating radius and high development costs for large-scale coal seams. Chemical reaction heating suffers from poor controllability and high safety risks. Indirect heating of coal seams through the rock's own heat conduction and radiation can effectively ensure the uniformity and controllability of heating oil-rich coal over a large area. Furthermore, using a combination of wind-solar hybrid power generation and thermal power generation can promote the effective absorption of unstable renewable energy sources, reduce carbon emissions, and lower the long-term economic cost of the system. Therefore, developing an in-situ pyrolysis system and method for oil-rich coal using rock as a heat carrier has significant practical implications. Summary of the Invention
[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide an in-situ pyrolysis system and method for oil-rich coal using rock as a heat carrier, which enriches the in-situ heating pathways for oil-rich coal and realizes uniform and large-scale heating of coal seams.
[0005] This invention is achieved through the following technical solution:
[0006] An in-situ pyrolysis system for oil-rich coal using rock as a heat carrier includes a pyrolysis block and a pyrolysis product separation device, a wind turbine, a photovoltaic power generation system, and a thermal power generator set arranged on the ground.
[0007] The pyrolysis block includes an oil-rich coal seam, an overlying stratum, and an underlying stratum. Vertically excavated from the ground surface are a new energy heating well for the overlying stratum, a supplementary heating well for the overlying stratum, a new energy heating well for the underlying stratum, a supplementary heating well for the underlying stratum, and a production well connected to the oil-rich coal seam. Temperature monitoring wells are excavated around the new energy heating wells for the overlying stratum, the supplementary heating wells for the underlying stratum, and the production well. High-temperature phase change material is injected and encapsulated around the lower ends of the new energy heating wells for the overlying stratum, the supplementary heating wells for the overlying stratum, the new energy heating wells for the underlying stratum, and the supplementary heating wells for the underlying stratum, forming a heating arrangement area that supplies energy to the strata.
[0008] The overlying and underlying rock strata of the oil-rich coal seam are electrically heated using wind turbines, photovoltaic power generation systems, and thermal power generator sets. The oil-rich coal seam is heated through heat conduction and radiation by the rock strata themselves, achieving in-situ pyrolysis of the oil-rich coal. Temperature monitoring wells are used to monitor the temperature of the oil-rich coal seam, overlying and underlying rock strata. When the heat release rate of the rock strata is too slow, thermal power generator sets are used to make minor adjustments to supplement the heating of the overlying and underlying rock strata. The in-situ pyrolysis products of the oil-rich coal flow out from the production well and are separated into liquid product tar and gaseous product pyrolysis gas by a pyrolysis product separation device.
[0009] Preferably, the high-temperature phase change material is a microencapsulated carbonate.
[0010] Preferably, supercritical CO2 carrying a catalyst is injected into the block along each vertical well to fracturing the overlying strata, underlying strata, and oil-rich coal seams to form a fracture network.
[0011] Preferably, a quadrilateral well layout is adopted, with the overlying strata new energy heating well, the overlying strata supplementary heating well, the underlying strata new energy heating well, and the underlying strata supplementary heating well located at the vertices of the quadrilateral, the production well located at the center of the quadrilateral, and the temperature detection well located near the new energy heating well and the production well, forming a pyrolysis well combination.
[0012] Preferably, the distance between the new energy heating well and the production well is about 10m, which is greater than the distance between the supplementary heating well and the production well.
[0013] Preferably, the thickness of the rock strata is greater than that of the coal seam, wherein when the thickness of the coal seam is about 10m, the thickness of the overlying rock strata and the thickness of the underlying rock strata are both about 160m, and a set of pyrolysis wells is arranged.
[0014] When the coal seam thickness is about 20m, the thickness of the overlying strata and the underlying strata is about 320m, and two sets of pyrolysis well combinations are arranged; and so on, multiple sets of pyrolysis well combinations are arranged at equal intervals according to the thickness of the coal seam and the underlying strata.
[0015] Preferably, the pyrolysis product separation device includes a gas-liquid separation device, a gas storage device, and an oil storage device. The in-situ pyrolysis products of oil-rich coal flow out of the production well, are initially cooled in a heat exchanger, and then enter the gas-liquid separation device to separate the liquid product tar and the gaseous product pyrolysis gas, which are stored in the oil storage device and the gas storage device, respectively.
[0016] The in-situ pyrolysis method for oil-rich coal using rock as a heat carrier includes the following steps:
[0017] 1) Supercritical CO2 carrying a catalyst is injected into the block along a vertical well to fracturing the overlying strata, underlying strata, and oil-rich coal seams, forming a fracture network;
[0018] 2) Use wind power, photovoltaic power and thermal power to provide energy to electrically heat the overlying and underlying rock strata of the oil-rich coal seam. Through the heat conduction and heat radiation of the rock strata themselves, the oil-rich coal seam can be indirectly, uniformly and over a large area.
[0019] 3) When renewable energy generation is large and the cost of generation is low, only wind-solar hybrid new energy power generation is implemented. When renewable energy generation is small and the cost of generation is high, thermal power generation is used as a supplementary heating method on the basis of wind-solar hybrid new energy power generation.
[0020] 4) The pyrolysis products flow out of the production well, are initially cooled in the heat exchanger, and then enter the pyrolysis product separation device to separate the liquid product tar and the gaseous product pyrolysis gas.
[0021] Preferably, after the fracture network is formed in the step, K2CO3 alkali metal compound is carried in supercritical CO2 and injected into the fracture network of the oil-rich coal seam.
[0022] This invention involves excavating a new energy heating well, a supplementary heating well, and a production well connected to the coal seam within a geological block. Temperature monitoring wells are excavated around the new energy heating well and the production well. High-temperature phase change material is injected and encapsulated around the lower end of the heating well, significantly improving the thermal storage capacity of the rock strata. Indirectly heating the coal seam through the rock avoids localized overheating or underheating, reduces the risk of damage to the heating well due to coal seam deformation, and extends the service life of the heating system. Furthermore, using wind-solar hybrid renewable energy generation as the primary energy supply method, supplemented by minor adjustments with traditional thermal power generation, significantly reduces carbon emissions and economic investment.
[0023] This invention electrically heats the overlying and underlying rock strata of a coal seam, achieving indirect, uniform, and large-scale heating of the coal seam through the heat conduction and radiation of the rock strata themselves. It also provides a feasible heating method for in-situ pyrolysis of oil-rich coal. By combining wind and solar hybrid power generation with thermal power generation, it effectively maintains the optimal pyrolysis efficiency of oil-rich coal while reducing the economic investment in long-term system operation and promoting the absorption of unstable renewable energy.
[0024] The present invention has at least the following beneficial technical effects:
[0025] (1) Excavate a heating well and connect it to the rock strata. The oil-rich coal seam is indirectly heated through the rock. The heat transfer is relatively mild, which can effectively reduce the problem of excessive pyrolysis and coking of coal and tar blockage of products near the heating area. At the same time, it reduces the risk of damage to the heating well caused by coal seam deformation and extends the service life of the heating system.
[0026] (2) When the wind is strong and the sunshine is sufficient, the renewable energy power generation is large and the power generation cost is low. At this time, only wind and solar complementary new energy power generation is implemented. When the renewable energy power generation is small and the power generation cost is high, thermal power generation is used to supplement heating on the basis of wind and solar complementary new energy power generation. Wind and solar complementary new energy power generation is the main energy supply method, supplemented by traditional thermal power generation for fine adjustment, which greatly reduces carbon emissions and promotes the effective absorption of unstable renewable energy.
[0027] (3) The marginal cost of wind-solar hybrid power generation is almost zero, which fundamentally reduces the economic investment required for the long-term operation of the entire system.
[0028] (4) First, the rocks near the coal seam are electrically heated, and then the coal seam is indirectly heated through the heat conduction and heat radiation of the rock strata themselves, thereby achieving large-scale uniform pyrolysis of the coal seam and enriching the heating pathways for in-situ pyrolysis of oil-rich coal.
[0029] (5) The high-temperature phase change material encapsulated in the lower end region of the heated well has a large latent heat of phase change, which can absorb or release a large amount of heat energy, thereby further improving the heat storage capacity of the rock.
[0030] (6) The use of microencapsulation process to prepare carbonate phase change materials avoids problems such as molten salt leakage, volume change and direct contact with surrounding rock, while effectively increasing the heat transfer area.
[0031] (7) Injecting fracturing fluid—supercritical CO2—into rock strata and coal seams. Its low viscosity and high diffusivity make it a liquid-like substance that can effectively penetrate the formation, thereby enhancing the fracturing ability and greatly improving the formation permeability.
[0032] (8) The alkali metal compounds such as K2CO3 carried in supercritical CO2 can significantly reduce the pyrolysis activation energy and increase the reaction rate; at the same time, they can inhibit the formation of coke and heavy tar and improve the quality of oil and gas products.
[0033] (9) After the oil-rich coal is fully pyrolyzed, the resulting pyrolysis semi-coke layer has a considerable specific surface area and pore volume, thus possessing a certain carbon sequestration potential and contributing to the realization of the "dual carbon" target. Attached Figure Description
[0034] Figure 1This is a schematic diagram of the structure of the oil-rich coal in-situ pyrolysis system using rock as a heat carrier according to the present invention;
[0035] Figure 2 This is a top view of the well layout structure in the in-situ pyrolysis system of the present invention;
[0036] Figure 3 This is a right view of the cross section containing the line connecting the production well and the supplementary heating well in the in-situ pyrolysis system of this invention;
[0037] Explanation of reference numerals in the attached diagram: 1 is the overlying stratum, 2 is the oil-rich coal seam, 3 is the underlying stratum, 4 is the overlying stratum's renewable energy heating well, 5 is the overlying stratum's supplementary heating well, 6 is the underlying stratum's renewable energy heating well, 7 is the underlying stratum's supplementary heating well, 8 is the production well, 9 is the temperature monitoring well, 10 is the encapsulated high-temperature phase change material, 11 is the heating arrangement area, 12 is the fracture network, 13 is the heat exchanger, 14 is the gas-liquid separation device, 15 is the gas storage device, 16 is the oil storage device, 17 is the wind turbine, 18 is the photovoltaic power generation system, and 19 is the thermal power generating unit. Detailed Implementation
[0038] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.
[0039] See Figure 1 As shown, the oil-rich coal in-situ pyrolysis system of the present invention, which uses rock as a heat carrier, includes a pyrolysis site and a heat exchanger 13, a gas-liquid separation device 14, a gas storage device 15, an oil storage device 16, a wind turbine generator 17, a photovoltaic power generation system 18, and a thermal power generator set 19 arranged on the ground.
[0040] The pyrolysis block includes an oil-rich coal seam 2, an overlying rock stratum 1, and an underlying rock stratum 3. Vertically excavating from the ground, a new energy heating well 4 for the overlying rock stratum, a supplementary heating well 5 for the overlying rock stratum, a new energy heating well 6 for the underlying rock stratum, a supplementary heating well 7 for the underlying rock stratum, and a production well 8 connected to the oil-rich coal seam, the temperature monitoring well 9 is excavated around the new energy heating well 4 for the overlying rock stratum, the new energy heating well 6 for the underlying rock stratum, and the production well 8, and high-temperature phase change material 10 is injected and encapsulated around the lower end of the heating well to form a heating arrangement area 11 that supplies energy to the rock stratum.
[0041] Supercritical CO2 was used to fracturing the overlying rock layer 1, the oil-rich coal seam 2, and the underlying rock layer 3 to form a fracture network 12. The fracturing fluid, carrying catalysts such as K2CO3 and other alkali metal compounds, was injected into the fracture network 12 of the oil-rich coal seam 2 along the production well, which effectively promoted coal pyrolysis.
[0042] The overlying strata 1 and underlying strata 3 of the oil-rich coal seam 2 are electrically heated, with wind and photovoltaic power generation as the energy source. Through the heat conduction and radiation of the strata themselves, the oil-rich coal seam 2 is indirectly, uniformly, and over a wide area heated, thereby initiating the in-situ pyrolysis reaction of the oil-rich coal. By monitoring the temperature of the oil-rich coal seam 2, the overlying strata 1, and the underlying strata 3, when the heat release rate of the strata is too slow, the overlying strata 1 and the underlying strata 3 are supplemented with heating, i.e., thermal power generation is used for fine-tuning.
[0043] The in-situ pyrolysis products of oil-rich coal flow out from production well 8, are initially cooled in heat exchanger 13, and then enter gas-liquid separation device 14. Finally, liquid product tar and gaseous product pyrolysis gas are separated and stored in oil storage device 16 and gas storage device 15, respectively.
[0044] First, the rock strata are electrically heated, and the heat from the rock strata is then slowly released to the oil-rich coal seam 2, thereby forming a relatively uniform temperature distribution in the oil-rich coal seam, avoiding local overheating or underheating, and reducing thermal stress problems caused by uneven heating. The overlying rock strata 1 and the underlying rock strata 3 are used as thermal storage bodies and electrically heated. The main energy supply methods are wind power generation and photovoltaic power generation. When the renewable energy power generation is large and the power generation cost is low, only wind and solar complementary new energy power generation is implemented. When the renewable energy power generation is small and the power generation cost is high, thermal power generation is used for supplementary heating.
[0045] Temperature monitoring is conducted on the rock strata and oil-rich coal seam 2 to prevent local temperatures from exceeding the limits of the formation or equipment. When the heat release rate of the rock strata is too slow, a combined energy supply method of thermal power generation is adopted, and supplementary heating wells are opened for fine-tuning to maintain the best pyrolysis efficiency.
[0046] See Figure 2 and Figure 3 As shown, the dashed lines only represent the geometry of the well layout. A quadrilateral layout is adopted. The overlying strata new energy heating well 4, the overlying strata supplementary heating well 5, the underlying strata new energy heating well 6, and the underlying strata supplementary heating well 7 are located at the vertices of the quadrilateral, respectively. The production well 8 is located at the center of the quadrilateral. The temperature monitoring well 9 is located near the new energy heating well and the production well, forming a group of pyrolysis wells. The depth of the new energy heating well, the supplementary heating well, and the production well extends to the middle of the corresponding strata and coal seams. The new energy heating well is about 10m apart from the production well 8, which is greater than the distance between the supplementary heating well and the production well 8.
[0047] The thickness of the rock strata is greater than that of coal seam 2, where coal seam 2 is about 10m thick and rock strata are about 160m thick. A set of pyrolysis wells is arranged there.
[0048] When the thickness of coal seam 2 is about 20m, two production wells 8 are arranged at equal intervals in the vertical direction of coal seam 2; when the thickness of overlying stratum 1 / underlying stratum 3 is about 320m, two new energy heating wells and two supplementary heating wells are arranged at equal intervals in the vertical direction of overlying stratum 1 / underlying stratum 3, that is, two sets of pyrolysis well combinations are arranged.
[0049] Similarly, multiple pyrolysis well combinations are arranged at equal intervals according to the coal seam thickness.
[0050] This invention comprehensively considers the combined energy supply method of in-situ pyrolysis of oil-rich coal using rock as a heat carrier and wind-solar hybrid new energy power generation combined with thermal power generation. Combined with a unique well layout method, it realizes indirect, uniform, and large-scale heating of coal seams, promotes the consumption of renewable energy, reduces the economic investment in long-term system operation, and provides a new idea for the heating path of in-situ pyrolysis of oil-rich coal.
[0051] This invention relates to an in-situ pyrolysis method for oil-rich coal using rock as a heat carrier, comprising the following steps:
[0052] 1) Supercritical CO2 carrying a catalyst is injected into the block along a vertical well to fracturing the overlying rock layer 1, the underlying rock layer 3 and the oil-rich coal seam 2, forming a fracture network 12. The supercritical CO2 carries alkali metal compounds such as K2CO3 and is injected into the fracture network 12 of the oil-rich coal seam 2.
[0053] 2) The overlying rock layer 1 and the underlying rock layer 3 of the oil-rich coal seam 2 are electrically heated, and the energy is supplied by wind power, photovoltaic power and thermal power. Through the heat conduction and heat radiation of the rock layer itself, the oil-rich coal seam 2 is indirectly, uniformly and over a large area heated.
[0054] 3) When renewable energy generation is large and the cost of generation is low, only wind-solar hybrid new energy power generation is implemented. When renewable energy generation is small and the cost of generation is high, thermal power generation is used as a supplementary heating method on the basis of wind-solar hybrid new energy power generation.
[0055] 4) The pyrolysis products flow out from the production well 8, are initially cooled in the heat exchanger 13, and then enter the gas-liquid separation device 14 to separate the liquid product tar and the gaseous product pyrolysis gas, which are stored in the oil storage device 16 and the gas storage device 15, respectively.
[0056] This invention electrically heats the surrounding rock of oil-rich coal seam 2, using a combined energy supply method of wind-solar hybrid new energy power generation and thermal power generation. Through the heat conduction and heat radiation of the rock strata themselves, the oil-rich coal seam 2 is indirectly, uniformly and over a large area heated, thereby initiating the in-situ pyrolysis reaction of the oil-rich coal.
[0057] When renewable energy generation is large and the cost of generation is low, only wind and solar complementary new energy power generation is implemented. When renewable energy generation is small and the cost of generation is high, thermal power generation is used for supplementary heating. By monitoring the temperature of the oil-rich coal seam 2, the overlying rock strata 1 and the underlying rock strata 3, when the heat release rate of the rock strata is too slow, the thermal power generator set 19 is used for fine adjustment. The pyrolysis products flow out from the production well 8, are cooled in the heat exchanger 13 and enter the gas-liquid separation device 14 to separate the liquid product tar and the gaseous product pyrolysis gas, which are stored in the oil storage device 16 and the gas storage device 15, respectively.
[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. An in-situ pyrolysis system for oil-rich coal using rock as a heat carrier, characterized in that: It includes pyrolysis plots and pyrolysis product separation devices arranged on the ground, wind turbines (17), photovoltaic power generation systems (18) and thermal power generator sets (19). The pyrolysis block includes an oil-rich coal seam (2), an overlying stratum (1), and an underlying stratum (3). Vertically excavated from the ground surface of the pyrolysis block are an overlying stratum new energy heating well (4), an overlying stratum supplementary heating well (5), an underlying stratum new energy heating well (6), an underlying stratum supplementary heating well (7), and a production well (8) connected to the oil-rich coal seam (2). Temperature monitoring wells (9) are excavated around the overlying stratum new energy heating well (4), the underlying stratum new energy heating well (6), and the production well (8). High-temperature phase change material (10) is injected and encapsulated around the lower ends of the overlying stratum new energy heating well (4), the overlying stratum supplementary heating well (5), the underlying stratum new energy heating well (6), and the underlying stratum supplementary heating well (7) to form a heating arrangement area (11) that supplies energy to the strata. A wind turbine (17), a photovoltaic power generation system (18), and a thermal power generator set (19) are used to provide power to electrically heat the overlying rock strata (1) and the underlying rock strata (3) of the oil-rich coal seam (2). Through the heat conduction and heat radiation of the rock strata themselves, the oil-rich coal seam (2) is heated to achieve the in-situ pyrolysis reaction of the oil-rich coal. The temperature of the oil-rich coal seam (2), the overlying rock strata (1), and the underlying rock strata (3) is monitored by a temperature monitoring well (9). When the heat release rate of the rock strata is too slow, the thermal power generator set (19) is used to provide power for fine adjustment to supplement the heating of the overlying rock strata (1) and the underlying rock strata (3). The in-situ pyrolysis products of the oil-rich coal flow out from the production well (8) and are separated by a pyrolysis product separation device to obtain liquid product tar and gaseous product pyrolysis gas. Supercritical CO2 carrying a catalyst is injected into the block along each vertical well to fracturing the overlying strata (1), the underlying strata (3), and the oil-rich coal seam (2) to form a fracture network (12). The well layout adopts a quadrilateral pattern. The overlying strata new energy heating well (4), the overlying strata supplementary heating well (5), the underlying strata new energy heating well (6) and the underlying strata supplementary heating well (7) are located at the vertices of the quadrilateral, the production well (8) is located at the center of the quadrilateral, and the temperature monitoring well (9) is located near the new energy heating well and the production well, forming a pyrolysis well combination. The distance between the new energy heating well and the production well (8) is about 10 m, which is greater than the distance between the supplementary heating well and the production well (8); The thickness of the rock strata is greater than that of the oil-rich coal seam (2), where the thickness of the oil-rich coal seam (2) is about 10 m, and the thickness of the overlying rock strata (1) and the underlying rock strata (3) is about 160 m. A set of pyrolysis wells is arranged. When the thickness of the oil-rich coal seam (2) is about 20 m, the thickness of the overlying strata (1) and the underlying strata (3) is about 320 m. Two sets of pyrolysis well combinations are arranged. In this way, multiple sets of pyrolysis well combinations are arranged at equal intervals according to the thickness of the coal seam and the strata. The pyrolysis product separation device includes a gas-liquid separation device (14), a gas storage device (15), and an oil storage device (16). The in-situ pyrolysis products of oil-rich coal flow out of the production well and are initially cooled in the heat exchanger (13) before entering the gas-liquid separation device (14) to separate the liquid product tar and the gaseous product pyrolysis gas, which are stored in the oil storage device (16) and the gas storage device (15), respectively.
2. The in-situ pyrolysis system for oil-rich coal using rock as a heat carrier according to claim 1, characterized in that: The high-temperature phase change material (10) is a microencapsulated carbonate.
3. The method for the in-situ pyrolysis system of oil-rich coal using rock as a heat carrier according to claim 2, characterized in that... Includes the following steps: 1) Supercritical CO2 carrying a catalyst is injected into the block along a vertical well to fracturing the overlying strata (1), the underlying strata (3) and the oil-rich coal seam (2) to form a fracture network (12). 2) Use wind power, photovoltaic power and thermal power to provide energy to electrically heat the overlying rock layer (1) and the underlying rock layer (3) of the oil-rich coal seam (2). Through the heat conduction and heat radiation of the rock layer itself, the oil-rich coal seam (2) can be indirectly, uniformly and over a wide range of heating is achieved. 3) When renewable energy generation is large and the cost of generation is low, only wind-solar hybrid new energy generation is implemented. When renewable energy generation is small and the cost of generation is high, thermal power generation is used as a supplementary heating method on the basis of wind-solar hybrid new energy generation. 4) The pyrolysis products flow out from the production well (8), are initially cooled in the heat exchanger (13), and then enter the pyrolysis product separation device to separate the liquid product tar and the gaseous product pyrolysis gas.
4. The in-situ pyrolysis method for oil-rich coal using rock as a heat carrier according to claim 3, characterized in that: After the fracture network (12) is formed in step 1), K2CO3 alkali metal compound is carried in supercritical CO2 and injected into the fracture network (12) of the oil-rich coal seam (2).