A trigeneration system for producing green methanol

Abstract

This invention relates to a combined heat and power (CHP) system for producing green methanol, comprising a supercritical carbon dioxide geothermal power generation system, a biomass gasification-coal combustion coupled system, and a green methanol production system. The supercritical carbon dioxide geothermal power generation system includes a production well, a turbine, a first cooler, a compressor, a second cooler, and an injection well, connected sequentially by pipelines. The biomass gasification-coal combustion coupled system includes a coal-fired boiler, a baking pretreatment device, a gasifier, a gas mixing device, and a preheater. The green methanol production system includes an electrolysis unit, a methanol storage tank, a carbon dioxide storage tank, a carbon dioxide capture device, a reaction vessel, and a water storage tank. This application combines the supercritical carbon dioxide geothermal power generation system, the biomass gasification-coal combustion coupled system, and the green methanol production system, organically combining and innovating previously dispersed and single-function new energy technologies, achieving comprehensive and complementary utilization of renewable energy, and meeting the product needs of different users.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, and in particular to a combined cooling, heating, and power (CCHP) system for producing green methanol. Background Technology

[0002] Against the backdrop of global efforts to address climate change and achieve carbon peaking and carbon neutrality, the traditional energy supply system, which is mainly based on fossil fuels, faces enormous challenges. Building a new power system with new energy sources as the mainstay has become a global consensus for addressing climate change and promoting energy transition.

[0003] Among the commonly seen new energy sources, solar and wind power are the fastest-growing. However, solar and wind power are characterized by randomness and volatility, requiring the integration of energy storage technologies to address their unstable power generation. Geothermal energy, as a native renewable energy source, boasts numerous advantages such as abundant resources, high energy efficiency, and immunity to diurnal and seasonal variations. However, due to the relatively low temperature and pressure of geothermal water or steam, its power generation efficiency is low, resulting in a limited number of geothermal power plants currently in operation.

[0004] Biomass energy is a renewable energy source with abundant reserves. Its high combustion temperature can significantly increase the initial temperature of the working fluid in the power cycle, and biomass power plant boilers are now widely used in rural areas. However, biomass energy has a low energy density, and as a power generation energy source, the utilization rate of direct combustion is only 10%, which seriously affects the overall efficiency of biomass power plants.

[0005] Therefore, how to effectively utilize the aforementioned new energy sources has become a crucial technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a combined heat and power (CHP) system for producing green methanol, which organically combines and innovates existing decentralized and single-function new energy technologies to achieve comprehensive and complementary utilization of renewable energy.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A combined heat and power (CHP) system for producing green methanol, comprising:

[0009] A supercritical carbon dioxide geothermal power generation system includes a production well, a turbine, a first cooler, a compressor, a second cooler, and an injection well. The production well, the turbine, the high-temperature end pipeline of the first cooler, the compressor, the high-temperature end pipeline of the second cooler, and the injection well are connected in sequence by pipelines.

[0010] A biomass gasification-coal-fired coupled system includes a coal-fired boiler, a baking pretreatment device, a gasifier, a gas mixing device, and a preheater. The high-temperature flue gas outlet of the coal-fired boiler is connected to the inlet of the high-temperature end pipeline of the gasifier. The gas mixing device is connected to the mixed gas inlet of the coal-fired boiler through the preheater. The gas outlet of the gasifier is connected to the gas inlet of the coal-fired boiler. The turbine is connected to the first cooler through the high-temperature end pipeline of the baking pretreatment device. The low-temperature end pipeline of the baking pretreatment device is connected to the raw material inlet of the gasifier. The pipeline between the production well and the turbine extends into the coal-fired boiler to exchange heat with the high-temperature flue gas.

[0011] A green methanol production system includes an electrolysis unit, a methanol storage tank, a carbon dioxide storage tank, a carbon dioxide capture device, a reaction vessel, and a water storage tank. The oxygen outlet of the electrolysis unit is connected to the oxygen inlet of the gas mixing device, and the hydrogen outlet of the electrolysis unit is connected to the hydrogen inlet of the reaction vessel. The outlet of the high-temperature end pipeline of the gasifier is connected sequentially through the high-temperature end pipeline of the reaction vessel, the high-temperature end pipeline of the preheater, and the inlet of the carbon dioxide capture device to the carbon dioxide storage tank. The outlet of the carbon dioxide storage tank is connected to the carbon dioxide inlet of the reaction vessel. The methanol outlet of the reaction vessel is connected to the methanol storage tank. The water outlet of the reaction vessel and the water outlet of the baking pretreatment device are connected to the water inlet of the water storage tank. The water outlet of the water storage tank is connected to the water inlet of the electrolysis unit.

[0012] Optionally, the supercritical carbon dioxide geothermal power generation system further includes a generator, which is connected to the turbine drive.

[0013] Optionally, the supercritical carbon dioxide geothermal power generation system further includes a first three-way valve, wherein the first valve port and the second valve port of the first three-way valve are connected in series between the high-temperature end pipeline of the first cooler and the compressor, and the third valve port of the first three-way valve is connected to the outlet of the carbon dioxide storage tank.

[0014] Optionally, it also includes a temperature control system, which includes a heating unit and / or a refrigeration unit, wherein the low-temperature end pipe of the first cooler and the low-temperature end pipe of the second cooler are connected in series with the temperature control system to form a loop.

[0015] Optionally, the temperature control system includes a heating unit, a refrigeration unit, a second three-way valve, and a third three-way valve. The first valve port of the second three-way valve is connected to the low-temperature end pipeline of the first cooler, the second valve port of the second three-way valve is connected to the inlet of the heating unit, the third valve port of the second three-way valve is connected to the inlet of the refrigeration unit, the first valve port of the third three-way valve is connected to the low-temperature end pipeline of the second cooler, the second valve port of the third three-way valve is connected to the outlet of the heating unit, and the third valve port of the third three-way valve is connected to the outlet of the refrigeration unit.

[0016] Optionally, the refrigeration unit is a lithium bromide refrigeration unit.

[0017] Optionally, the green methanol preparation system further includes a power supply system for supplying power to the electrolysis unit.

[0018] Optionally, the power supply system includes a solar photovoltaic power generation system and / or a wind power generation system.

[0019] Optionally, the electrolysis device includes an electrolytic cell, an oxygen storage tank, and a hydrogen storage tank. The inlet of the electrolytic cell is connected to the outlet of the water storage tank. The oxygen outlet of the electrolytic cell is connected to the oxygen inlet of the oxygen storage tank. The oxygen outlet of the oxygen storage tank is connected to the oxygen inlet of the gas mixing device. The hydrogen outlet of the electrolytic cell is connected to the hydrogen inlet of the hydrogen storage tank. The hydrogen outlet of the hydrogen storage tank is connected to the hydrogen inlet of the reaction vessel.

[0020] Optionally, the coal-fired boiler includes a boiler body and a screw feeder, wherein the screw feeder is connected to the fuel inlet of the boiler body.

[0021] As can be seen from the above technical solutions, this invention discloses a combined heat and power (CHP) system for producing green methanol. This CHP system includes a supercritical carbon dioxide geothermal power generation system, a biomass gasification-coal combustion coupling system, and a green methanol production system. The supercritical carbon dioxide geothermal power generation system includes a production well, a turbine, a first cooler, a compressor, a second cooler, and an injection well. The production well, turbine, high-temperature end pipelines of the first cooler, compressor, high-temperature end pipelines of the second cooler, and injection well are sequentially connected by pipelines. The biomass gasification-coal combustion coupling system includes a coal-fired boiler, a baking pretreatment device, a gasifier, a gas mixing device, and a preheater. The high-temperature flue gas outlet of the coal-fired boiler is connected to the inlet of the high-temperature end pipeline of the gasifier. The gas mixing device is connected to the mixed gas inlet of the coal-fired boiler through the preheater. The gas outlet of the gasifier is connected to the gas inlet of the coal-fired boiler. The turbine is connected to the high-temperature end pipeline of the baking pretreatment device. The high-temperature end pipeline is connected to the first cooler, and the low-temperature end pipeline of the baking pretreatment unit is connected to the raw material inlet of the gasifier. The pipeline between the production well and the turbine enters the coal-fired boiler to exchange heat with the high-temperature flue gas. The green methanol production system includes an electrolysis unit, a methanol storage tank, a carbon dioxide storage tank, a carbon dioxide capture device, a reaction vessel, and a water storage tank. The oxygen outlet of the electrolysis unit is connected to the oxygen inlet of the gas mixing device, and the hydrogen outlet of the electrolysis unit is connected to the hydrogen inlet of the reaction vessel. The outlet of the high-temperature end pipeline of the gasifier is connected to the inlet of the carbon dioxide storage tank via the high-temperature end pipeline of the reaction vessel, the high-temperature end pipeline of the preheater, and the carbon dioxide capture device. The outlet of the carbon dioxide storage tank is connected to the carbon dioxide inlet of the reaction vessel. The methanol outlet of the reaction vessel is connected to the methanol storage tank. The water outlet of the reaction vessel and the water outlet of the baking pretreatment unit are connected to the water inlet of the water storage tank. The water outlet of the water storage tank is connected to the water inlet of the electrolysis unit.

[0022] In application, the production well and injection well of the supercritical carbon dioxide geothermal power generation system are respectively set in the geothermal reservoir. The supercritical carbon dioxide in the geothermal reservoir absorbs the heat from the deep geothermal layer and becomes high-temperature gaseous carbon dioxide, which is produced by the production well. After being heated by the coal-fired boiler, it becomes high-temperature and high-pressure carbon dioxide and enters the turbine to do work. The exhaust steam generated by the turbine enters the baking pretreatment device for heat exchange, and then enters the first cooler to be cooled to about 35°C. Subsequently, it enters the compressor for compression, and finally enters the second cooler to be cooled to about 30°C by cooling water before entering the injection well.

[0023] In the biomass gasification-coal-fired coupled system, the biomass feedstock first passes through a baking pretreatment unit to absorb waste heat from turbine exhaust steam, increasing the gas yield in the subsequent gasification process. Water generated during baking is collected in a storage tank of the green methanol production system for use in the electrolysis unit. The baked solid products enter the gasifier for pyrolysis and gasification. The resulting gasification ash is collected through a discharge port and used for soil improvement and crop yield enhancement. The biomass gas is then co-fired with coal in a coal-fired boiler. The resulting high-temperature flue gas enters the gasifier to provide heat for biomass gasification, then enters the reaction vessel to provide heat for the synthesis of methanol from hydrogen and carbon dioxide. Next, the mixed gas enters a preheater to heat the mixture, and finally enters a carbon dioxide capture and treatment unit to separate and store the carbon dioxide in a carbon dioxide storage tank.

[0024] In the green electricity methanol production system, the oxygen generated by electrolysis is mixed with air in a gas mixing device and then enters the preheater. The hydrogen generated by electrolysis is stored in a hydrogen storage tank and reacts with carbon dioxide from a carbon dioxide storage tank in a reaction vessel under the action of a catalyst to produce methanol and water. The generated methanol is stored in a methanol storage tank and transported out as an important industrial raw material and energy carrier. The produced water is stored in a water storage tank and mixed with water generated from the roasting of biomass raw materials to serve as electrolytic water in the electrolysis unit.

[0025] In summary, this application combines a supercritical carbon dioxide geothermal power generation system, a biomass gasification coal-fired coupling system, and a green methanol production system. This organically combines and innovates previously dispersed and single-function new energy technologies, achieving comprehensive and complementary utilization of renewable energy to meet the product needs of different users. The supercritical carbon dioxide geothermal power generation system utilizes the superior heat-carrying capacity and higher heat extraction efficiency of supercritical carbon dioxide. Furthermore, over time, a portion of the carbon dioxide injected into the underground circulation is permanently stored underground, serving as a carbon dioxide sequestration method. Under the premise of a stable and reliable carbon dioxide source, the power generation cost can be comparable to conventional thermal power, and the power generation is stable, reliable, and highly flexible. The carbon dioxide gas is heated through heat exchange in a coal-fired boiler before entering the turbine to perform work, which can be used for power generation or driving other equipment, resulting in higher efficiency. The high-temperature carbon dioxide gas after turbine work enters a baking pretreatment device to pre-treat the biomass raw materials, promoting cross-linking and carbonization reactions in the biomass, increasing the gas yield of biomass gasification. Simultaneously, the water produced during the baking process can be used for electrolysis to produce hydrogen, improving energy utilization efficiency.

[0026] The green electricity methanol production system can use wind / solar power as off-grid electricity to supply the electrolysis unit, avoiding the instability of wind / solar power grid connection and reducing the auxiliary equipment required for grid-connected wind / solar operation, significantly reducing investment and construction costs. It converts perishable electrical energy into hydrogen and oxygen, solving the problems of wind / solar energy storage and utilization. Simultaneously, the oxygen produced by electrolysis is preheated before entering the furnace of a coal-fired boiler. Combustion in an oxygen-rich environment increases combustion temperature and power generation efficiency, while reducing pollution emissions by increasing the proportion of water and carbon dioxide in the flue gas. Carbon dioxide can be easily captured at the downstream end using water separation technology. The produced hydrogen and the captured carbon dioxide in the flue gas catalytically produce methanol, not only absorbing a large amount of carbon dioxide but also solving the hydrogen storage and transportation problem. Furthermore, the water produced in the reaction can be recycled for hydrogen production through electrolysis, greatly reducing water consumption.

[0027] The biomass gasification-coal-fired coupled system converts biomass into fuel gas in a gasifier, which is then fed into a coal-fired boiler to be mixed with coal for power generation. This solves the problem of low energy density of biomass energy as a power generation source and fully utilizes the energy of gasification sensible heat and tar, improving power generation efficiency and reducing pollutant emissions. The high-temperature flue gas generated by the coal-fired boiler first enters the gasifier to provide heat for biomass gasification, then enters the methanol reaction vessel to provide the heat required for the chemical reaction, and finally enters the preheater to heat oxygen, achieving cascaded energy utilization and improving energy efficiency. This method can fully leverage the advantages of large-scale coal-fired power generation units, with lower initial investment costs, shorter construction periods, flexible biomass utilization scale, and the ability to self-regulate in response to fluctuations in coal and biomass prices. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the combined cooling, heating, and power (CCHP) system for preparing green methanol disclosed in an embodiment of the present invention.

[0030] in:

[0031] 1 is the production well; 2 is the coal-fired boiler; 3 is the turbine; 4 is the generator; 5 is the baking pretreatment unit; 6 is the first cooler; 7 is the first three-way valve; 8 is the compressor; 9 is the second cooler; 10 is the injection well; 11 is the thermal reservoir; 12 is the heating unit; 13 is the refrigeration unit; 14 is the gasifier; 15 is the induced draft fan; 16 is the reaction vessel; 17 is the gas mixing device; 18 is the preheater; 19 is the carbon dioxide capture device; 20 is the carbon dioxide storage tank; 21 is the oxygen storage tank; 22 is the hydrogen storage tank; 23 is the power supply system; 24 is the electrolyzer; 25 is the methanol storage tank; 26 is the water storage tank; 27 is the slag discharge port; 28 is the second three-way valve; 29 is the third three-way valve; 30 is the screw feeder; 31 is the gas booster pump; 32 is the water pump; 33 is the oxygen booster pump; 34 is the blower. Detailed Implementation

[0032] The core of this invention is to provide a combined heat and power (CHP) system for producing green methanol. The structural design of this CHP system enables the organic combination and innovation of existing decentralized and single-function new energy technologies, thereby achieving comprehensive and complementary utilization of renewable energy.

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of the combined cooling, heating, and power (CCHP) system for preparing green methanol disclosed in an embodiment of the present invention.

[0035] This invention discloses a combined heat and power (CHP) system for preparing green methanol, which includes a supercritical carbon dioxide geothermal power generation system, a biomass gasification coal combustion coupling system, and a green methanol preparation system.

[0036] The supercritical carbon dioxide geothermal power generation system includes a production well 1, a turbine 3, a first cooler 6, a compressor 8, a second cooler 9, and an injection well 10. The high-temperature end pipes of the production well 1, turbine 3, first cooler 6, compressor 8, second cooler 9, and injection well 10 are connected in sequence through pipes. The first cooler 6 and the second cooler 9 can be water-cooled or other cooling methods, which are not limited here.

[0037] The biomass gasification-coal-fired coupled system includes a coal-fired boiler 2, a baking pretreatment device 5, a gasifier 14, a gas mixing device 17, and a preheater 18. The high-temperature flue gas outlet of the coal-fired boiler 2 is connected to the inlet of the high-temperature end pipeline of the gasifier via an induced draft fan 15. The gas mixing device 17 is used to mix air and oxygen generated during the electrolysis process of the green methanol preparation system. The gas mixing device 17 is connected to the mixed gas inlet of the coal-fired boiler 2 via the preheater 18. The preheater 18 and the mixed gas inlet of the coal-fired boiler 2 are connected by air supply. The gasifier 14 is connected to the gas inlet of the coal-fired boiler 2 via a gas booster pump 31. The gas booster pump 31 pressurizes the gas output from the gasifier 14 and inputs it into the coal-fired boiler 2. The turbine 3 is connected to the first cooler 6 via the high-temperature end pipeline of the baking pretreatment device 5. The low-temperature end pipeline of the baking pretreatment device 5 is connected to the raw material inlet of the gasifier 14. The pipeline between the output well 1 and the turbine 3 passes into the coal-fired boiler 2 to exchange heat with the high-temperature flue gas.

[0038] The green methanol production system includes an electrolysis unit, a methanol storage tank 25, a carbon dioxide storage tank 20, a carbon dioxide capture device 19, a reaction vessel 16, and a water storage tank 26. The oxygen outlet of the electrolysis unit is connected to the oxygen inlet of the gas mixing device 17, and the hydrogen outlet of the electrolysis unit is connected to the hydrogen inlet of the reaction vessel 16. The outlet of the high-temperature end pipeline of the gasifier is connected to the inlet of the carbon dioxide storage tank 20 via the high-temperature end pipeline of the reaction vessel 16, the high-temperature end pipeline of the preheater 18, and the carbon dioxide capture device 19. The outlet of the carbon dioxide storage tank 20 is connected to the carbon dioxide inlet of the reaction vessel 16. The methanol outlet of the reaction vessel 16 is connected to the methanol storage tank 25. The water outlet of the reaction vessel 16 and the water outlet of the baking pretreatment device 5 are connected to the water inlet of the water storage tank 26. The water outlet of the water storage tank 26 is connected to the water inlet of the electrolysis unit via a water pump 32.

[0039] In application, the supercritical carbon dioxide geothermal power generation system's output well 1 and injection well 10 are respectively set in the thermal reservoir 11. The supercritical carbon dioxide in the thermal reservoir 11 absorbs the heat from the deep geothermal layer and becomes high-temperature gaseous carbon dioxide, which is produced by the output well 1. After being heated by the coal-fired boiler 2, it becomes high-temperature and high-pressure carbon dioxide and enters the turbine 3 to do work. The exhaust steam generated by the turbine 3 enters the baking pretreatment device 5 for heat exchange, and then enters the first cooler 6 to be cooled to about 35°C. Subsequently, it enters the compressor 8 for compression, and finally enters the second cooler 9 to be cooled by cooling water to about 30°C before entering the injection well 10.

[0040] In the biomass gasification-coal-fired coupled system, the biomass feedstock first passes through a baking pretreatment device 5 to absorb waste heat from the turbine 3, increasing the gas yield in the subsequent gasification process. The water produced during baking is collected in the water storage tank 26 of the green methanol preparation system for use in the electrolysis unit. The baked solid products enter the gasifier 14 for pyrolysis and gasification. The gasification ash is collected through the ash discharge port 27 and used for soil improvement and crop yield enhancement. The biomass gas enters the coal-fired boiler 2 for co-combustion with coal. The resulting high-temperature flue gas enters the gasifier 14 to provide heat for biomass gasification, then enters the reaction vessel 16 to provide heat for the synthesis of methanol from hydrogen and carbon dioxide. Next, it enters the preheater 18 to heat the mixed gas, and finally enters the carbon dioxide capture and treatment device to separate carbon dioxide and store it in the carbon dioxide storage tank 20.

[0041] In the biomass gasification-coal-fired coupled system, the biomass gasification temperature is controlled between 700℃ and 800℃. The mixed gas exiting preheater 18 has an oxygen content of ≥40% and a temperature of 200℃, providing an oxygen-rich atmosphere for combustion in the gas-fired boiler.

[0042] In the green electricity methanol production system, the oxygen generated by electrolysis is mixed with air in the gas mixing device 17 and then enters the preheater 18. The hydrogen generated by electrolysis is stored in the hydrogen storage tank 22 and reacts with carbon dioxide from the carbon dioxide storage tank 20 in the reaction vessel 16 under the action of a catalyst to generate methanol and water. The generated methanol is stored in the methanol storage tank 25 and transported out as an important industrial raw material and energy carrier. The produced water is stored in the water storage tank 26 and mixed with the water generated from the roasting of biomass raw materials to serve as the electrolyzed water of the electrolysis device.

[0043] In the green electricity methanol production system, the temperature for synthesizing methanol from hydrogen and carbon dioxide is controlled between 300℃ and 400℃.

[0044] As can be seen, compared with existing technologies, the combined heat and power (CHP) system for preparing green methanol provided in this embodiment of the invention integrates a supercritical carbon dioxide geothermal power generation system, a biomass gasification coal-fired coupling system, and a green methanol preparation system. This organically combines and innovates previously dispersed and single-function new energy technologies, achieving comprehensive and complementary utilization of renewable energy to meet the product needs of different users. The supercritical carbon dioxide geothermal power generation system utilizes the stronger heat-carrying capacity and higher heat extraction rate of supercritical carbon dioxide. Furthermore, over time, a portion of the carbon dioxide injected into the underground circulation will be permanently sealed underground, serving as a carbon dioxide sequestration method. Under the premise of a stable and reliable carbon dioxide source, the power generation cost can be comparable to conventional thermal power, and the power generation is stable, reliable, and highly flexible. The carbon dioxide gas is heated by heat exchange in the coal-fired boiler 2 before entering the turbine 3 to perform work, which can be used for power generation or driving other equipment, resulting in higher efficiency. The high-temperature carbon dioxide gas after performing work in the turbine 3 enters the baking pretreatment device 5 to pre-treat the biomass raw materials, promoting cross-linking and carbonization reactions in the biomass, increasing the gas yield of biomass gasification, and simultaneously, the water produced during the baking process can be used for electrolysis to produce hydrogen, improving energy utilization.

[0045] The oxygen produced by the electrolysis in the green electricity methanol production system is preheated before entering the furnace of coal-fired boiler 2. Combustion of the fuel in an oxygen-rich environment increases combustion temperature and power generation efficiency while reducing pollution emissions. This increases the proportion of water and carbon dioxide in the emitted flue gas, allowing for easy capture of carbon dioxide using water separation technology at the downstream end. The produced hydrogen reacts with the captured carbon dioxide in the flue gas to catalytically generate methanol. This not only absorbs a large amount of carbon dioxide but also solves the problem of hydrogen storage and transportation. Furthermore, the water produced in the reaction can be recycled for hydrogen electrolysis, significantly reducing water consumption.

[0046] The biomass gasification-coal-fired coupling system converts biomass into fuel gas in gasifier 14, which is then fed into coal-fired boiler 2 for combustion and power generation. This solves the problem of low energy density of biomass as a power generation energy source and fully utilizes the energy of gasification sensible heat and tar, improving power generation efficiency and reducing pollutant emissions. The high-temperature flue gas generated by the combustion in coal-fired boiler 2 first enters gasifier 14 to provide heat for biomass gasification, then enters methanol reaction vessel 16 to provide the heat required for chemical reactions, and finally enters preheater 18 to heat oxygen, achieving cascaded energy utilization and improving energy efficiency. This method can fully leverage the advantages of large-scale coal-fired power generation units (4 units), with lower initial investment costs, shorter construction periods, flexible biomass utilization scale, and the ability to self-regulate in response to fluctuations in coal and biomass prices.

[0047] Preferably, in an embodiment of the present invention, such as Figure 1 As shown, the supercritical carbon dioxide geothermal power generation system also includes a generator 4, which is connected to the turbine 3 via a transmission.

[0048] like Figure 1 As shown, the supercritical carbon dioxide geothermal power generation system also includes a first three-way valve 7. The first valve port and the second valve port of the first three-way valve 7 are connected in series between the high-temperature end pipeline of the first cooler 6 and the compressor 8. The third valve port of the first three-way valve 7 is connected to the outlet of the carbon dioxide storage tank 20.

[0049] When the carbon dioxide pressure at the outlet of the production well 1 is detected to be too low, the first three-way valve 7 is opened to connect the carbon dioxide storage tank 20. The carbon dioxide storage tank 20 mixes with the carbon dioxide gas in the geothermal power generation system and enters the compressor 8. The resulting supercritical carbon dioxide is injected into the underground dry hot rock reservoir through the injection well 10.

[0050] Optionally, the combined cycle power system for preparing green methanol in this embodiment of the invention further includes a temperature control system, which includes a heating unit 12 and / or a refrigeration unit 13. The low-temperature end pipeline of the first cooler 6 and the low-temperature end pipeline of the second cooler 9 are connected in series with the temperature control system to form a loop.

[0051] Specifically, such as Figure 1 As shown, the temperature control system includes a heating unit 12, a refrigeration unit 13, a second three-way valve 28, and a third three-way valve 29. The first valve port of the second three-way valve 28 is connected to the low-temperature end pipeline of the first cooler 6, the second valve port of the second three-way valve 28 is connected to the inlet of the heating unit 12, and the third valve port of the second three-way valve 28 is connected to the inlet of the refrigeration unit 13. The first valve port of the third three-way valve 29 is connected to the low-temperature end pipeline of the second cooler 9, the second valve port of the third three-way valve 29 is connected to the outlet of the heating unit 12, and the third valve port of the third three-way valve 29 is connected to the outlet of the refrigeration unit 13.

[0052] During operation, the circulating water absorbs the waste heat from the exhaust steam of turbine 3 through the first cooler 6 and the second cooler 9. When cooling in summer, the first and third valve ports of the second three-way valve 28, the first and third valve ports of the third three-way valve 29, and the switch of the refrigeration unit 13 are opened to utilize the waste heat for cooling. When heating in winter, the first and second valve ports of the second three-way valve 28, the first and second valve ports of the third three-way valve 29, and the switch of the heat pump unit are opened to utilize the heat pump to increase efficiency and raise the temperature for heating.

[0053] Specifically, in this embodiment of the invention, the refrigeration unit 13 is a lithium bromide refrigeration unit 13.

[0054] To further optimize the above technical solution, in this embodiment of the invention, the green methanol preparation system also includes a power supply system 23 for supplying power to the electrolysis unit. Specifically, the power supply system 23 includes a solar photovoltaic power generation system and / or a wind power generation system, using wind / solar power as off-grid electricity to supply the electrolysis unit, avoiding the problem of unstable grid connection of wind / solar power, reducing the auxiliary equipment required for grid-connected wind / solar operation, significantly reducing investment and construction costs, and simultaneously converting the difficult-to-store electrical energy into hydrogen and oxygen, solving the problems of wind / solar energy storage and consumption.

[0055] like Figure 1 As shown, in this embodiment of the invention, the electrolysis device includes an electrolytic cell 24, an oxygen storage tank 21, and a hydrogen storage tank 22. The inlet of the electrolytic cell 24 is connected to the outlet of the water storage tank 26. The oxygen outlet of the electrolytic cell 24 is connected to the oxygen inlet of the oxygen storage tank 21. The oxygen outlet of the oxygen storage tank 21 is connected to the oxygen inlet of the gas mixing device 17 via an oxygen booster pump 33. The hydrogen outlet of the electrolytic cell 24 is connected to the hydrogen inlet of the hydrogen storage tank 22. The hydrogen outlet of the hydrogen storage tank 22 is connected to the hydrogen inlet of the reaction vessel 16.

[0056] like Figure 1 As shown, the coal-fired boiler 2 includes a boiler body and a screw feeder 30. The screw feeder 30 is connected to the fuel inlet of the boiler body. It should be noted that in other embodiments, the coal-fired boiler 2 may also use other feeding methods, which are not limited here.

[0057] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0058] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A combined cooling, heating, and power (CCHP) system for producing green methanol, characterized in that, include: A supercritical carbon dioxide geothermal power generation system includes a production well, a turbine, a first cooler, a compressor, a second cooler, and an injection well. The production well, the turbine, the high-temperature end pipeline of the first cooler, the compressor, the high-temperature end pipeline of the second cooler, and the injection well are connected in sequence by pipelines. A biomass gasification-coal-fired coupled system includes a coal-fired boiler, a baking pretreatment device, a gasifier, a gas mixing device, and a preheater. The high-temperature flue gas outlet of the coal-fired boiler is connected to the inlet of the high-temperature end pipeline of the gasifier. The gas mixing device is connected to the mixed gas inlet of the coal-fired boiler through the preheater. The gas outlet of the gasifier is connected to the gas inlet of the coal-fired boiler. The turbine is connected to the first cooler through the high-temperature end pipeline of the baking pretreatment device. The low-temperature end pipeline of the baking pretreatment device is connected to the raw material inlet of the gasifier. The pipeline between the production well and the turbine extends into the coal-fired boiler to exchange heat with the high-temperature flue gas. A green methanol production system includes an electrolysis unit, a methanol storage tank, a carbon dioxide storage tank, a carbon dioxide capture device, a reaction vessel, and a water storage tank. The oxygen outlet of the electrolysis unit is connected to the oxygen inlet of the gas mixing device, and the hydrogen outlet of the electrolysis unit is connected to the hydrogen inlet of the reaction vessel. The outlet of the high-temperature end pipeline of the gasifier is connected sequentially through the high-temperature end pipeline of the reaction vessel, the high-temperature end pipeline of the preheater, and the inlet of the carbon dioxide capture device to the carbon dioxide storage tank. The outlet of the carbon dioxide storage tank is connected to the carbon dioxide inlet of the reaction vessel. The methanol outlet of the reaction vessel is connected to the methanol storage tank. The water outlet of the reaction vessel and the water outlet of the baking pretreatment device are connected to the water inlet of the water storage tank. The water outlet of the water storage tank is connected to the water inlet of the electrolysis unit.

2. The combined cycle power (CEP) system for preparing green methanol according to claim 1, characterized in that, The supercritical carbon dioxide geothermal power generation system also includes a generator, which is connected to the turbine drive.

3. The combined cycle power (CEP) system for preparing green methanol according to claim 1, characterized in that, The supercritical carbon dioxide geothermal power generation system also includes a first three-way valve, wherein the first and second valve ports of the first three-way valve are connected in series between the high-temperature end pipeline of the first cooler and the compressor, and the third valve port of the first three-way valve is connected to the outlet of the carbon dioxide storage tank.

4. The combined cycle power (CCHP) system for preparing green methanol according to any one of claims 1-3, characterized in that, It also includes a temperature control system, which includes a heating unit and / or a refrigeration unit, wherein the low-temperature end pipe of the first cooler and the low-temperature end pipe of the second cooler are connected in series with the temperature control system to form a loop.

5. The combined cycle power (CEP) system for preparing green methanol according to claim 4, characterized in that, The temperature control system includes a heating unit, a refrigeration unit, a second three-way valve, and a third three-way valve. The first valve port of the second three-way valve is connected to the low-temperature end pipeline of the first cooler, the second valve port of the second three-way valve is connected to the inlet of the heating unit, the third valve port of the second three-way valve is connected to the inlet of the refrigeration unit, the first valve port of the third three-way valve is connected to the low-temperature end pipeline of the second cooler, the second valve port of the third three-way valve is connected to the outlet of the heating unit, and the third valve port of the third three-way valve is connected to the outlet of the refrigeration unit.

6. The combined cycle power (CEP) system for preparing green methanol according to claim 5, characterized in that, The refrigeration unit is a lithium bromide refrigeration unit.

7. The combined cycle power (CEP) system for preparing green methanol according to any one of claims 1-3, 5 and 6, characterized in that, The green methanol production system also includes a power supply system for supplying power to the electrolysis unit.

8. The combined cycle power (CEP) system for preparing green methanol according to claim 7, characterized in that, The power supply system includes a solar photovoltaic power generation system and / or a wind power generation system.

9. The combined heat and power (CHP) system for preparing green methanol according to any one of claims 1-3, 5, 6 and 8, characterized in that, The electrolysis device includes an electrolytic cell, an oxygen storage tank, and a hydrogen storage tank. The inlet of the electrolytic cell is connected to the outlet of the water storage tank. The oxygen outlet of the electrolytic cell is connected to the oxygen inlet of the oxygen storage tank. The oxygen outlet of the oxygen storage tank is connected to the oxygen inlet of the gas mixing device. The hydrogen outlet of the electrolytic cell is connected to the hydrogen inlet of the hydrogen storage tank. The hydrogen outlet of the hydrogen storage tank is connected to the hydrogen inlet of the reaction vessel.

10. The combined heat and power (CHP) system for preparing green methanol according to any one of claims 1-3, 5, 6 and 8, characterized in that, The coal-fired boiler includes a boiler body and a screw feeder, the screw feeder being connected to the fuel inlet of the boiler body.

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