A supercritical thermal power unit coordinated power generation and hydrogen production system

Abstract

The present invention relates to the technical field of coal-fired thermal power generation and supercritical water gasification hydrogen production, and specifically to a supercritical thermal power unit coordinated power generation and hydrogen production system. The system includes a steam transport system, a reaction device, a material transport system, a product waste heat utilization system, and a product separation system; the steam transport system is connected to the steam inlet of the reaction device; the product waste heat utilization system includes a material preheating device, a first heat exchange unit, and a second heat exchange unit; the material preheating device is connected to the material transport system, and the material preheating device is connected to the first heat exchange unit; the first heat exchange unit is connected to the reaction device; the discharge port of the reaction device is respectively connected to the material preheating device and the first heat exchange unit; the first heat exchange unit is connected to the second heat exchange unit, and the second heat exchange unit is connected to the product separation system. The present invention can ensure that the boiler operates at a safe load while using the remaining steam to efficiently produce hydrogen from coal slime wastewater, thereby improving hydrogen production efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired thermal power generation and supercritical water gasification hydrogen production, and in particular to a supercritical thermal power unit coordinated power generation and hydrogen production system. Background Art

[0002] To ensure a clean and green energy transition, coal-fired power generation units will transition to providing basic support and system regulation power sources in the future, fully leveraging the flexible operation capabilities of thermal power units. Deep peak shaving will become the norm for coal-fired units. Under deep peak shaving, power plant boilers will inevitably operate alternately between full load and significantly lower loads, sometimes even operating at loads as low as 25% to 15% for extended periods. This variable load and lower load operation is particularly prone to unstable furnace combustion, subjecting the boiler's heating surfaces to frequent temperature fluctuations. This increases the risk of high-temperature heating surface tube bursts and creep fracture failures.

[0003] The coal in the power plant contains a large amount of coal slime wastewater. Therefore, in order to reduce the operating risk of the boiler under variable load and low load, the power plant can maintain the boiler operating at a relatively safe and economic load. While ensuring the power supply load, the remaining load can be used to produce hydrogen from the coal slime wastewater using supercritical water. This can achieve the utilization of the remaining load while ensuring the power supply load, obtain a certain amount of economic income, and improve the economy of the power plant.

[0004] Supercritical water gasification (SCWG) can convert organic matter, such as coal, into a hydrogen-rich mixture consisting of hydrogen, carbon dioxide, methane, and carbon monoxide. SCWG has garnered widespread attention for its green and efficient hydrogen production applications. However, the high manufacturing and operating costs of the equipment associated with the SCWG process make the construction of a standalone SCWG hydrogen production unit uneconomical.

[0005] Furthermore, existing coal-fired power plants coupled with supercritical water hydrogen production systems fail to efficiently utilize waste heat from the reaction, resulting in high energy consumption and often impure hydrogen, reducing hydrogen production efficiency. Therefore, developing an efficient and energy-efficient supercritical hydrogen production system has become a key technical direction. Summary of the Invention

[0006] In order to solve the problems of safe operation of boilers with variable loads and low efficiency and high operating cost of coupled hydrogen production of coal-fired power plants, the purpose of the present invention is to provide a supercritical thermal power plant coordinated power generation and hydrogen production system.

[0007] To achieve the above objectives, the technical solutions of the present invention are as follows.

[0008] The first aspect of the present invention provides a supercritical thermal power unit coordinated power generation and hydrogen production system, comprising a steam transport system, a reaction device, a material transport system, a product waste heat utilization system and a product separation system; the steam transport system is connected to the steam inlet of the reaction device; the product waste heat utilization system comprises a material preheating device, a first heat exchange unit and a second heat exchange unit; the first inlet of the material preheating device is connected to the material transport system, and the first outlet of the material preheating device is connected to the first inlet of the first heat exchange unit to heat the material and increase the temperature; the first outlet of the first heat exchange unit is connected to the feed inlet of the reaction device to perform a supercritical water gasification hydrogen production reaction in the reaction device to produce a solid phase product and a gas-liquid Two-phase product; the first discharge port of the reaction device is connected to the second inlet of the material preheating device; the second discharge port of the reaction device is connected to the second inlet of the first heat exchange unit; the second outlet of the first heat exchange unit is connected to the product inlet of the second heat exchange unit, and the product outlet of the second heat exchange unit is connected to the product separation system to separate and store hydrogen; the product separation system includes a hydrogen separation unit, a CO2 separation unit and a solution storage unit; the product outlet of the second heat exchange unit is connected to the hydrogen separation unit, the CO2 separation unit and the solution storage unit in sequence; the outlet of the solution storage unit is connected to the inlet of the salt treatment device, and the outlet of the salt treatment device is connected to the inlet of the material preparation device.

[0009] The present invention utilizes a steam transport system to provide excess steam generated by excess load to a reaction device, and carries out a supercritical water hydrogen production reaction of coal slime wastewater with materials provided by a material transport system. While ensuring that the boiler operates at a safe load, the excess steam is used to efficiently produce hydrogen from the coal slime wastewater, thereby improving hydrogen production efficiency. The present invention solves the problems of safe operation of boilers with variable loads and low efficiency and high operating cost of coupled hydrogen production of coal-fired power units.

[0010] Preferably, the steam transport system includes a boiler, a first steam output end of the boiler is connected to a steam turbine, and the steam turbine is connected to a generator; a second steam output end of the boiler is connected to a steam inlet of the reaction device.

[0011] Preferably, the material conveying system includes a material mixing device, a low-pressure delivery pump, a material buffer device, an air compressor, and a high-pressure delivery pump. The outlet of the material mixing device is connected to the inlet of the low-pressure delivery pump, the outlet of the low-pressure delivery pump is connected to the first inlet of the material buffer device, and the second inlet of the material buffer device is connected to the air compressor to provide air; the first outlet of the material buffer device is connected to the inlet of the high-pressure delivery pump, and the outlet of the high-pressure delivery pump is connected to the first inlet of the material preheating device. The present invention increases the oxygen content of the material and improves the efficiency of supercritical water gasification hydrogen production by adding an air compressor above the material buffer device.

[0012] Preferably, the second outlet of the first heat exchange unit is connected to a salt storage device, which is configured to store the solid phase product in the salt storage device after heat exchange and cooling.

[0013] Preferably, the heat exchange tube inlet of the second heat exchange unit is connected to the boiler's condenser downstream pipe to provide condensed water to the second heat exchange unit; the heat exchange tube outlet of the second heat exchange unit is connected to the power plant system's purification unit. Specifically, the power plant system's purification unit includes a low-pressure heater, a deaerator, and a high-pressure heater, all of which are components of the power plant system. The heat exchange tube outlet of the second heat exchange unit is sequentially connected to the low-pressure heater, deaerator, and high-pressure heater in the power plant system, allowing the heat exchanged water to be purified by the low-pressure heater, deaerator, and high-pressure heater before re-entering the boiler body.

[0014] Preferably, the product separation system includes a hydrogen separation unit, a CO2 separation unit, and a solution storage unit; the product outlet of the second heat exchange unit is sequentially connected to the hydrogen separation unit, the CO2 separation unit, and the solution storage unit; the outlet of the solution storage unit is connected to the inlet of the salt treatment device, and the outlet of the salt treatment device is connected to the inlet of the material preparation device. The product separation system of the present invention can produce relatively pure hydrogen by adding alkali, and relatively pure CO2 by adding acid. The resulting salty water is then re-entered into the material preparation device for material preparation.

[0015] Preferably, the hydrogen separation unit includes a first buffer unit, an alkali solution supply unit and a hydrogen storage unit, the product inlet of the first buffer unit is connected to the product outlet of the second heat exchange unit, the top spray head in the first buffer unit is connected to the alkali solution supply unit through a pipeline, and the hydrogen outlet of the first buffer unit is connected to the hydrogen storage unit.

[0016] Preferably, the CO2 separation unit includes a second buffer unit, an acid liquid supply unit and a CO2 storage unit; the liquid outlet of the first buffer unit is connected to the second buffer unit, the top spray head in the second buffer unit is connected to the acid liquid supply unit, and the CO2 outlet of the second buffer unit is connected to the CO2 storage unit.

[0017] Preferably, a CO2 detection unit is arranged on the pipeline between the first buffer unit and the hydrogen storage unit, a first switch valve is arranged on the pipeline between the first buffer unit and the alkali solution supply unit, and the CO2 detection unit is interlocked with the first switch valve; a second switch valve is arranged on the pipeline between the second buffer unit and the acid solution supply unit, a carbonate ion detection device is provided at the inlet of the solution storage unit, and the carbonate ion detection device is interlocked with the second switch valve.

[0018] Beneficial effects of the present invention:

[0019] 1. The present invention utilizes a steam transport system to provide excess steam generated by excess load to the reaction device, and carries out a supercritical water hydrogen production reaction of coal slime wastewater with the material provided by the material transport system. While ensuring that the boiler operates at a safe load, the excess steam is used to efficiently produce hydrogen from the coal slime wastewater, thereby improving the hydrogen production efficiency; and solving the problems of safe operation of boilers with variable loads and low efficiency and high operating costs of hydrogen production coupled with coal-fired power units.

[0020] 2. The present invention utilizes the waste heat of the reaction products of supercritical water gasification to produce hydrogen. A portion of the waste heat of the products is used to heat the materials, reducing the heat absorption of the materials in the reaction device. The remaining waste heat of the products is used to heat the boiler feed water and enters the low-pressure heater, deaerator and high-pressure heater of the power station system, thereby increasing the temperature of the low-pressure heater and the high-pressure heater, reducing the steam extraction of the turbine, and improving the power generation efficiency of the unit.

[0021] 3. The product separation system described in the present invention can separate hydrogen from the product and produce high-purity hydrogen. At the same time, it can capture CO2 in the product and reduce the carbon emissions of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a system for a supercritical thermal power unit coordinated power generation and hydrogen production system provided in an embodiment of the present invention.

[0023] Description of reference numerals:

[0024] 1. Reaction device; 2. Material mixing device; 3. Low-pressure delivery pump; 4. Material buffer device; 5. Air compressor; 6. High-pressure delivery pump; 7. Material preheating device; 8. Salt storage device; 9. Second heat exchange unit; 10. First buffer unit; 11. Alkali solution supply unit; 12. CO2 detection unit; 13. First heat exchange unit; 14. Hydrogen storage unit; 15. Acid solution supply unit; 16. Second buffer unit; 17. Carbonate ion detection device; 18. CO2 storage unit; 19. Solution storage unit; 20. Deaerator and high-pressure heater; 21. Low-pressure heater; 22. Salt treatment device; 23. Boiler; 24. Steam turbine; 25. Generator; V1. Steam switching valve; V2. Exhaust valve; V3. Check valve; V4. First material switching valve; V5. Second material switching valve; V6. Back pressure valve; V7. First pressure reducing valve; V8. First switching valve; V9. Second pressure reducing valve; V10. Second switching valve. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0027] Supercritical water gasification (SCWG) can convert organic matter, such as coal, into a hydrogen-rich mixture consisting of hydrogen, carbon dioxide, methane, and carbon monoxide. SCWG has garnered widespread attention for its green and efficient hydrogen production applications. However, the high manufacturing and operating costs of the equipment associated with the SCWG process make the construction of a standalone SCWG hydrogen production unit uneconomical.

[0028] Therefore, by maintaining the boiler at a relatively safe and economical load, while ensuring the power supply load, and efficiently utilizing the boiler's remaining load for supercritical gasification hydrogen production, not only can safe operation of the boiler under variable load conditions be guaranteed, but it can also enable the power plant to generate a certain amount of economic income, thereby improving the plant's economic efficiency. Furthermore, existing coal-fired power units coupled with supercritical water hydrogen production systems fail to efficiently utilize the reaction waste heat, resulting in high energy consumption, and the produced hydrogen is often impure, reducing hydrogen production efficiency. Therefore, developing an efficient and energy-saving supercritical hydrogen production system has become an important technical direction.

[0029] The technical solution of the present invention is further described below by means of specific examples. In the following examples, the methods described are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0030] like Figure 1A supercritical thermal power unit coordinated power generation and hydrogen production system includes a steam transport system, a reaction unit 1, a material transport system, a product waste heat utilization system and a product separation system; the steam transport system is connected to the steam inlet of the reaction unit 1; the product waste heat utilization system includes a material preheating device 7, a first heat exchange unit 13 and a second heat exchange unit 9; the first inlet of the material preheating device 7 is connected to the material transport system, and the first outlet of the material preheating device 7 is connected to the first inlet of the first heat exchange unit 13 to heat the material and increase the temperature; the first outlet of the first heat exchange unit 13 is connected to the feed inlet of the reaction unit 1 to carry out a supercritical water gasification hydrogen production reaction in the reaction unit 1 to produce a solid-phase product and a gas-liquid two-phase product; the first discharge port of the reaction unit 1 is connected to the second inlet of the material preheating device 7; the second discharge port of the reaction unit 1 is connected to the second inlet of the first heat exchange unit 13; the second outlet of the first heat exchange unit 13 is connected to the product inlet of the second heat exchange unit 9, and the product outlet of the second heat exchange unit 9 is connected to the product separation system to separate and store hydrogen.

[0031] Based on the above embodiment, as a more preferred embodiment, the steam transportation system includes a boiler 23. The first steam output end of the boiler 23 is connected to a steam turbine 24 to convert thermal energy into mechanical energy. The rotor of the steam turbine 24 is connected to the rotor of a generator 25 to convert mechanical energy into electrical energy. The second steam output end of the boiler 23 is connected to the steam inlet of the reaction device 1. The second steam output end of the boiler 23 is equipped with a steam on / off valve V1 to regulate the steam flow entering the reaction device 1.

[0032] Specifically, the boiler 23 is a power plant boiler 23. Part of the steam from the boiler 23 is supplied to the steam turbine 24 for generating electricity, and the remaining steam flows through the steam switching valve V1 and enters the reaction device 1. The steam switching valve V1 is interlocked with the operating load of the boiler 23.

[0033] Specifically, the process by which steam is supplied to the steam turbine 24 to generate power is as follows: the first steam output terminal of the boiler 23 is connected to the steam turbine 24; the high-temperature, high-pressure steam generated by the combustion of fuel in the boiler 23 is the primary carrier of thermal energy; the steam drives the blades in the steam turbine 24 to rotate, converting thermal energy into mechanical energy; the rotor of the steam turbine 24 is connected to the generator 25, which uses the rotational kinetic energy of the rotor to drive the generator 25 to generate electricity, thereby converting mechanical energy into electrical energy. It should be noted that the water in the boiler 23 is heated to boiling and vaporized, forming high-temperature, high-pressure steam. This high-temperature, high-pressure steam enters the steam turbine 24 through a pipe; within the steam turbine 24, the high-temperature, high-pressure steam is injected between the blades of the turbine 24, performing work on the blades, driving them to rotate, thereby converting the steam's thermal energy into mechanical energy. The steam turbine 24 consists of a rotor and a stator, with the rotor of the steam turbine 24 connected to the rotor of the generator 25. The rotational kinetic energy of the rotor of the steam turbine 24 is transmitted to the rotor of the generator 25 via a shaft. Generator 25 has a rotor with wire windings installed inside. When the rotor rotates in a magnetic field, the wire windings cut through the magnetic lines of force, generating an induced electromotive force, which in turn generates an electric current. The current generated by generator 25 is output through wires and connected to the power grid for human use.

[0034] Based on the above embodiment, as a more preferred embodiment, the material conveying system includes a material preparation device 2, a low-pressure delivery pump 3, a material buffer device 4, an air compressor 5, and a high-pressure delivery pump 6. The outlet of the material preparation device 2 is connected to the inlet of the low-pressure delivery pump 3, which is connected to the first inlet of the material buffer device 4, and the second inlet of the material buffer device 4 is connected to the air compressor 5. The first outlet of the material buffer device 4 is connected to the inlet of the high-pressure delivery pump 6, the second outlet of the material buffer device 4 has an exhaust valve V2, and the outlet of the high-pressure delivery pump 6 is connected to the first inlet of the material preheating device 7. The first outlet of the material preheating device 7 is connected to the first inlet of the first heat exchange unit 13, and the first outlet of the first heat exchange unit 13 is connected to the reaction device 1.

[0035] Specifically, the material preparation device 2 is used to adjust the ratio of coal sludge and wastewater to serve as the feed for supercritical water hydrogen production. The wastewater is specifically coal sludge wastewater generated by a power plant. After entering the material preparation device 2, the resulting material is transported by a low-pressure delivery pump 3 to a material buffer device 4. An air compressor 5 is located above the material buffer device 4 to supply air to the material buffer device 4 to increase the oxygen content of the material. For enhanced safety, an exhaust valve V2 is located above the material buffer device 4 to regulate the pressure within the material buffer device 4. The material is transported from the material buffer device 4 by a high-pressure delivery pump 6, passes through a check valve V3 and a first material on-off valve V4, and is then transported to a material preheating device 7. The material preheating device 7 preheats the material and transports the preheated material to a first heat exchange unit 13. The first heat exchange unit 13 further heats the material, raising its temperature so that, after reaching a predetermined temperature, it enters the reactor 1 through the material on-off valve V5. Among them, the medium-pressure delivery pump 3 and the high-pressure delivery pump 6 are interlocked with the steam switching valve V1.

[0036] Based on the above embodiment, as a more preferred embodiment, the product waste heat utilization system includes a material preheating device 7 and a first heat exchange unit 13. The first inlet of the material preheating device 7 is connected to the high-pressure delivery pump 6 of the material delivery system, and the first outlet of the material preheating device 7 is connected to the first inlet of the first heat exchange unit 13 to heat the material and increase its temperature; the first outlet of the first heat exchange unit 13 is connected to the feed port of the reaction device 1 to further heat the material and increase its temperature before feeding it into the reaction device 1. The second inlet of the material preheating device 7 is connected to the first discharge port of the reaction device 1, and the second outlet of the material preheating device 7 is connected to the salt storage device 8 to allow the solid phase product obtained by the reaction of the reaction device 1 to be stored in the salt storage device 8 after heat exchange and cooling. The second discharge port of the reaction device 1 is connected to the second inlet of the first heat exchange unit 13.

[0037] Specifically, the product waste heat utilization system includes a first heat exchange unit 13 and a material preheating device 7 below the reaction device 1. The material preheating device 7 is used to preheat the material, which is then heated again by the first heat exchange unit 13 and then sent to the reaction device 1, thereby improving reaction efficiency and energy utilization. The material in the reaction device 1 undergoes a supercritical water gasification reaction with supercritical steam to produce a solid-phase product and a gas-liquid two-phase product. The solid-phase product obtained by the reaction in the reaction device 1 is cooled by heat exchange in the material preheating device 7 and then stored in the salt storage device 8 provided below the material preheating device 7. The gas-liquid two-phase product obtained by the reaction in the reaction device 1 is then cooled by heat exchange in the first heat exchange unit 13 and sent to the second heat exchange unit 9.

[0038] Based on the above embodiment, as a more preferred embodiment, the product waste heat utilization system also includes a second heat exchange unit 9, the second inlet of the first heat exchange unit 13 is connected to the second discharge port of the reaction device 1, the second outlet of the first heat exchange unit 13 is connected to the product inlet of the second heat exchange unit 9, and the product outlet of the second heat exchange unit 9 is connected to the product separation system. The heat exchange tube inlet of the second heat exchange unit 9 is connected to the condenser rear pipe of the boiler, the heat exchange tube outlet of the second heat exchange unit 9 is connected to the inlet of the purification unit of the power station system, and the outlet of the purification unit is connected to the water inlet of the boiler. Specifically, the purification unit of the power station system includes a low-pressure heater, a deaerator, and a high-pressure heater. The low-pressure heater, deaerator, and high-pressure heater are all equipment in the power station system. The heat exchange tube outlet of the second heat exchange unit is connected to the low-pressure heater, deaerator, and high-pressure heater in the power station system in sequence, so that the water after heat exchange is purified by the low-pressure heater, deaerator, and high-pressure heater before re-entering the boiler body.

[0039] Specifically, the product outlet of the first heat exchange unit 13 is connected to the product inlet of the second heat exchange unit 9, which is then connected to the product separation system. The heat exchange medium of the second heat exchange unit 9 is condensate from the boiler 23, which is provided by the boiler feedwater system. After heat exchange and cooling in the first heat exchange unit 13, the gas-liquid two-phase product in the reaction unit 1 is fed into the second heat exchange unit 9, where it exchanges heat with condensate provided by the pipeline after the boiler's condenser. After heat exchange, the condensate enters the power plant system's low-pressure heater 21, deaerator, and high-pressure heater 20, and finally enters the boiler 23.

[0040] Based on the above embodiment, as a more preferred embodiment, the product separation system includes a hydrogen separation unit, a CO2 separation unit, and a solution storage unit 19; the product outlet of the second heat exchange unit 9 is sequentially connected to the hydrogen separation unit, the CO2 separation unit, and the solution storage unit 19. The outlet of the solution storage unit 19 is connected to the inlet of the salt treatment device 22, and the outlet of the salt treatment device 22 is connected to the inlet of the material preparation device 2.

[0041] Specifically, the hydrogen separation unit is used to separate and store hydrogen; the CO2 separation unit is used to separate and store CO2; and the solution storage unit 19 is used to store the remaining salt solution after separation. The salt solution stored in the solution storage unit 19 is then processed by the salt treatment device 22 before re-entering the material preparation device 2. The salt treatment device 22 is used to remove excess salt from the water. The salt treatment device 22 can be an existing desalination device, such as an ion exchange desalination device or a reverse osmosis desalination device currently available on the market.

[0042] On the basis of the above embodiment, as a more preferred embodiment, the hydrogen separation unit includes a first buffer unit 10, an alkali solution supply unit 11 and a hydrogen storage unit 14, the product inlet of the first buffer unit 10 is connected to the product outlet of the second heat exchange unit 9, the top spray head in the first buffer unit 10 is connected to the alkali solution supply unit 11 through a pipeline, and the hydrogen outlet of the first buffer unit 10 is connected to the hydrogen storage unit 14.

[0043] Specifically, a back-pressure valve V6 and a first pressure-reducing valve V7 are installed on the pipeline between the second heat exchange unit 9 and the first buffer unit 10. The gas-liquid two-phase product passes through the back-pressure valve V6 and the first pressure-reducing valve V7 in sequence before entering the first buffer unit 10. An alkaline solution supply unit 11 is located above the first buffer unit 10. This alkaline solution sprays the hydrogen in the first buffer unit 10, and the resulting high-purity hydrogen enters the hydrogen storage unit 14.

[0044] On the basis of the above embodiment, as a more preferred embodiment, a CO2 detection unit 12 is arranged on the pipeline between the first buffer unit 10 and the hydrogen storage unit 14, and a first switch valve V8 is arranged on the pipeline between the first buffer unit 10 and the alkali solution supply unit 11. The CO2 detection unit 12 is connected to the first switch valve V8 through a wire to control the opening and closing of the first switch valve V8.

[0045] Specifically, the CO2 detection unit 12 is used to detect the gas entering the hydrogen storage unit 14, so that hydrogen that meets the purity requirements enters the hydrogen storage unit 14 through the pipeline. When the CO2 detection unit 12 detects that the hydrogen purity is lower than the set requirement, the CO2 detection unit 12 controls the first switch valve V8 to open to remove CO2 in the gas and further improve the purity of the hydrogen.

[0046] Based on the above embodiment, as a more preferred embodiment, the CO2 separation unit includes a second buffer unit 16, an acid liquid supply unit 15 and a CO2 storage unit 18; the liquid outlet of the first buffer unit 10 is connected to the second buffer unit 16, the top spray head in the second buffer unit 16 is connected to the acid liquid supply unit 15, and the CO2 outlet of the second buffer unit 16 is connected to the CO2 storage unit 18.

[0047] Specifically, a second pressure reducing valve V9 is installed on the pipeline between the first buffer unit 10 and the second buffer unit 16. The liquid product from the first buffer unit 10 passes through the second pressure reducing valve V9, converting into CO2 and a salt solution. This solution then enters the second buffer unit 16, where the CO2 is precipitated by the acid supply unit 15 and stored in the CO2 storage unit 18.

[0048] On the basis of the above embodiment, as a more preferred embodiment, a second switch valve V10 is arranged on the pipeline between the second buffer unit 16 and the acid supply unit 15, and a carbonate ion detection device 17 is provided at the inlet of the solution storage unit 19. The carbonate ion detection device 17 is connected to the second switch valve V10 through a wire to control the opening and closing of the second switch valve V10.

[0049] Specifically, the carbonate ion detection device 17 is used to detect the liquid entering the solution storage unit 19. The carbonate ion detection device 17 arranged in front of the solution storage unit 19 is interlocked with the second switch valve V10. When a higher concentration of carbonate ions is detected, the second switch valve V10 is opened to allow all the CO2 dissolved in the water to precipitate.

[0050] In the embodiment of the present invention, the gas-liquid two-phase products pass through the back pressure valve V6 and the first pressure reducing valve V7 in sequence and then enter the first buffer unit 10. An alkali solution supply unit 11 is provided above the first buffer unit 10. The alkali solution sprays the hydrogen in the first buffer unit 10, and the generated high-purity hydrogen enters the hydrogen storage unit 14. A CO2 detection unit 12 is provided in front of the hydrogen storage unit 14. The remaining liquid phase product passes through the second pressure reducing valve V9 and enters the second buffer unit 16. The second buffer unit 16 is provided with an acid supply unit 15. The CO2 generated in the second buffer unit 16 enters the CO2 storage unit 18; the remaining salt solution enters the solution storage unit 19, and then passes through the salt treatment device 22 before re-entering the material preparation device 2; wherein, a CO2 detection unit 12 is provided at the inlet of the hydrogen storage unit 14, and the CO2 detection unit 12 is interlocked with the first switch valve V8. A carbonate ion detection device 17 is provided at the inlet of the solution storage unit 19, and the carbonate ion detection device 17 is interlocked with the second switch valve V10.

[0051] The specific implementation of the supercritical thermal power unit coordinated power generation and hydrogen production system is as follows:

[0052] When the boiler 23 needs to reduce the power generation load while operating under a safe load, the boiler 23 can be maintained in operation under a safe load, a portion of the steam is used to supply the steam turbine 24 with power generation, and the remaining steam passes through the steam switch valve V1 interlocked with the power generation load of the boiler 23 and enters the reaction device 1 for supercritical water gasification hydrogen production reaction.

[0053] At the same time, the low-pressure delivery pump 3 and high-pressure delivery pump 6, which are interlocked with the steam on-off valve V1, are opened at a certain flow rate. The low-pressure delivery pump 3 delivers wastewater and coal sludge to the material buffer device 4. An air compressor 5 is installed above the material buffer device 4 to increase the oxygen content in the material and improve the efficiency of supercritical water gasification hydrogen production. An exhaust valve V2 is also installed on the top of the buffer tank 4. After leaving the material buffer device 4, the material is pressurized to the reaction pressure by the high-pressure delivery pump 6. Thereafter, it passes through the check valve V3 and the material on-off valve V4 in sequence and enters the material preheating device 7. After exiting the material preheating device 7, it enters the first heat exchange unit 13 for heat exchange, passes through the second material on-off valve V5, and finally enters the reaction device 1 to undergo a supercritical water gasification reaction with the supercritical steam.

[0054] The solid phase product in the reaction product passes through the material preheating device 7 and enters the salt storage device 8. The gas-liquid two-phase product passes through the first heat exchange unit 13 to exchange heat with the material, and then enters the second heat exchange unit 9 to exchange heat with the boiler feed water. The heated feed water enters the low-pressure heater 21, the deaerator and the high-pressure heater 20 in sequence, and then enters the boiler 23, thereby increasing the steam temperature of the low-pressure heater 21, reducing the steam extraction of the turbine 24, and improving the power generation efficiency of the unit.

[0055] The cooled gas-liquid two-phase products are separated. The gas-liquid two-phase products at the outlet of the second heat exchange unit 9 pass through the back pressure valve V6 and the first pressure reducing valve V7 and enter the first buffer unit 10. The gaseous hydrogen product from the first buffer unit 10 enters the hydrogen storage unit 14. An alkaline solution supply unit is provided above the first buffer unit 10 and is interlocked with the CO2 detection unit 12 at the inlet of the hydrogen storage unit 14. When CO2 is detected, the first on-off valve V8 is opened, and an alkaline solution is sprayed above the first buffer unit 10 to absorb the CO2 in the gaseous products. The liquid phase product from the first buffer unit 10 passes through the second pressure reducing valve V9 and is converted into CO2 and salt solution. It enters the second buffer unit 16, where all CO2 in the product is precipitated by the acid supply unit 15, and the salt solution is stored in the solution storage unit 19. Finally, the salt solution in the solution storage unit 19 passes through the salt treatment device 22 and enters the material preparation device 2. The carbonate ion detection device 17 provided in front of the solution storage unit 19 is interlocked with the second switch valve V10. When a certain concentration of carbonate ions is detected, the second switch valve V10 is opened to allow all CO2 dissolved in the water to precipitate.

[0056] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A supercritical thermal power unit coordinated power generation and hydrogen production system, characterized in that: It comprises a steam transport system, a reaction device (1), a material transport system, a product waste heat utilization system and a product separation system; the steam transport system is connected to the steam inlet of the reaction device (1); The product waste heat utilization system comprises a material preheating device (7), a first heat exchange unit (13) and a second heat exchange unit (9); the first inlet of the material preheating device (7) is connected to the material conveying system, and the first outlet of the material preheating device (7) is connected to the first inlet of the first heat exchange unit (13) to heat the material and increase its temperature; the first outlet of the first heat exchange unit (13) is connected to the feed port of the reaction device (1) to perform a supercritical water gasification hydrogen production reaction in the reaction device (1) to produce a solid phase product and a gas-liquid two-phase product; The first discharge port of the reaction device (1) is connected to the second inlet of the material preheating device (7); the second discharge port of the reaction device (1) is connected to the second inlet of the first heat exchange unit (13); The second outlet of the first heat exchange unit (13) is connected to the product inlet of the second heat exchange unit (9), and the product outlet of the second heat exchange unit (9) is connected to the product separation system to separate and store hydrogen; The product separation system includes a hydrogen separation unit, a CO2 separation unit, and a solution storage unit (19); the product outlet of the second heat exchange unit (9) is connected to the hydrogen separation unit, the CO2 separation unit, and the solution storage unit (19) in sequence; the outlet of the solution storage unit (19) is connected to the inlet of the salt treatment device (22), and the outlet of the salt treatment device (22) is connected to the inlet of the material preparation device (2); The steam transport system comprises a boiler (23), a first steam output end of the boiler (23) is connected to a steam turbine (24), and the steam turbine (24) is connected to a generator (25); a second steam output end of the boiler (23) is connected to a steam inlet of the reaction device (1); The material conveying system comprises a material mixing device (2), a low-pressure conveying pump (3), a material buffer device (4), an air compressor (5) and a high-pressure conveying pump (6), wherein the outlet of the material mixing device (2) is connected to the inlet of the low-pressure conveying pump (3), the outlet of the low-pressure conveying pump (3) is connected to the first inlet of the material buffer device (4), and the second inlet of the material buffer device (4) is connected to the air compressor (5) to provide air; The first outlet of the material buffer device (4) is connected to the inlet of the high-pressure delivery pump (6), and the outlet of the high-pressure delivery pump (6) is connected to the first inlet of the material preheating device (7).

2. The supercritical thermal power unit coordinated power generation and hydrogen production system according to claim 1, characterized in that: The second outlet of the first heat exchange unit (13) is connected to a salt storage device (8), and is configured to allow the solid phase product to enter the salt storage device (8) for storage after heat exchange and temperature reduction.

3. The supercritical thermal power unit coordinated power generation and hydrogen production system according to claim 1, characterized in that: The heat exchange pipe inlet of the second heat exchange unit (9) is connected to the condenser rear pipe of the boiler (23) to provide condensed water to the second heat exchange unit (9); the heat exchange pipe outlet of the second heat exchange unit (9) is connected to the purification unit of the power station system.

4. The supercritical thermal power unit coordinated power generation and hydrogen production system according to claim 1, characterized in that: The hydrogen separation unit comprises a first buffer unit (10), an alkali solution supply unit (11) and a hydrogen storage unit (14); the product inlet of the first buffer unit (10) is connected to the product outlet of the second heat exchange unit (9); the top spray head in the first buffer unit (10) is connected to the alkali solution supply unit (11) through a pipeline; and the hydrogen outlet of the first buffer unit (10) is connected to the hydrogen storage unit (14).

5. The supercritical thermal power unit coordinated power generation and hydrogen production system according to claim 4, characterized in that: The CO2 separation unit comprises a second buffer unit (16), an acid liquid supply unit (15) and a CO2 storage unit (18); the liquid outlet of the first buffer unit (10) is connected to the second buffer unit (16), the top spray head in the second buffer unit (16) is connected to the acid liquid supply unit (15), and the CO2 outlet of the second buffer unit (16) is connected to the CO2 storage unit (18).

6. The supercritical thermal power unit coordinated power generation and hydrogen production system according to claim 5, characterized in that: A CO2 detection unit (12) is arranged on the pipeline between the first buffer unit (10) and the hydrogen storage unit (14), a first switch valve is arranged on the pipeline between the first buffer unit (10) and the alkali solution supply unit (11), and the CO2 detection unit (12) is interlocked with the first switch valve; A second switch valve is provided on the pipeline between the second buffer unit (16) and the acid solution supply unit (15), and a carbonate ion detection device (17) is provided at the inlet of the solution storage unit (19), and the carbonate ion detection device (17) is interlocked with the second switch valve.

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