Hydrogen direct-fired compressed CO2 energy storage system coupled with solid hydrogen storage

Abstract

The invention relates to a hydrogen direct-fired compressed CO2 energy storage system coupled with solid hydrogen storage, the hydrogen direct-fired compressed CO2 energy storage system comprises a solid hydrogen storage unit, a hydrogen direct-fired unit and a compressed CO2 energy storage unit, the solid hydrogen storage unit is connected with an inlet of the hydrogen direct-fired unit, and an outlet of the hydrogen direct-fired unit is connected with an inlet of the compressed CO2 energy storage unit; an outlet of the compressed CO2 energy storage unit is connected with an inlet of the hydrogen direct combustion unit; the compressed CO2 energy storage unit comprises at least two sections of compression devices, and each section of compression device is provided with an interstage heat exchanger. The system has the characteristics of zero carbon emission, safety, high efficiency and high energy utilization rate, and supports power grid peak regulation and zero carbon technologies.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage power generation, and particularly to a hydrogen direct combustion compressed CO2 energy storage system coupled with solid-state hydrogen storage. Background Art

[0002] A hydrogen gas turbine is a gas turbine technology that uses hydrogen as fuel and drives a turbine to generate electricity or output power through combustion. With the decline in the cost of green hydrogen and technological breakthroughs, hydrogen gas turbines are expected to become one of the main power sources in the carbon neutrality era, promoting the transformation of the energy structure from being dominated by fossil energy to being dominated by hydrogen energy and renewable energy. Currently, there are some demonstration projects related to pure hydrogen gas turbines or hydrogen-blended gas turbines at home and abroad, which have confirmed the potential of pure hydrogen or hydrogen-blended gas turbines in engineering applications and emission reduction fields. The hydrogen direct combustion compressed CO2 energy storage technology couples hydrogen gas turbines and compressed CO2 energy storage technology, and has the characteristics of zero carbon emissions and strong rotational inertia support. It can be used as a regulating power source in scenarios such as new energy bases, microgrids, and off-grid new energy hydrogen production, supporting deep grid peaking and zero-carbon transformation.

[0003] Based on the current technical conditions, in order to enable a hydrogen gas turbine power generation system to maintain continuous and stable operation for a long time, a relatively large-sized high-pressure gaseous hydrogen storage system is often configured, and the hydrogen storage amount of the high-pressure gaseous hydrogen storage system is directly related to its hazard level and supervision specifications. Taking a 30MW pure hydrogen gas turbine as an example, its hydrogen consumption per kWh is about 0.18kg / kWh, and the hydrogen consumption per hour under rated conditions is about 5400kg. Calculated based on continuous operation for 4 hours during conventional peaking operation, 22 tons of hydrogen need to be stored. According to GB18218-2018 "Identification of Major Hazard Sources of Hazardous Chemicals", the high-pressure gaseous hydrogen storage system with this hydrogen storage amount already belongs to a major hazard source, with high potential safety hazards, and high-standard design, operation, maintenance, and supervision and other work need to be carried out, which will have a significant adverse impact on the investment cost and daily operation of the entire project.

[0004] In the prior art, there are defects that the high-pressure gaseous hydrogen storage system supporting a hydrogen gas turbine is bulky, and when the hydrogen storage amount reaches the peak shaving requirement, it constitutes a major hazard source, with prominent potential safety hazards and significantly pushing up the project investment cost and operation and maintenance costs. Therefore, how to achieve long-term continuous and stable operation of a hydrogen gas turbine while avoiding major safety risks in the hydrogen storage link, reducing the comprehensive cost of the system, and adapting to the regulation requirements of a zero-carbon power system has become an urgent problem to be solved at present. Summary of the Invention

[0005] To address the aforementioned technical challenges, this invention replaces traditional high-pressure gaseous hydrogen storage with high-density, low-risk solid-state hydrogen storage. Simultaneously, it leverages the closed-loop cycle characteristics of CO2 compression energy storage to meet the peak-shaving operation requirements of hydrogen gas turbines. Through multi-stage compression and interstage heat exchange, it achieves gradient energy utilization, ensuring long-term stable operation of the system in peak-shaving scenarios, reducing risks, saving costs, and improving energy efficiency.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a hydrogen direct-fired compressed CO2 energy storage system coupled with solid-state hydrogen storage. The hydrogen direct-fired compressed CO2 energy storage system includes: a solid-state hydrogen storage unit, a hydrogen direct-fired unit, and a compressed CO2 energy storage unit. The solid-state hydrogen storage unit is connected to the inlet of the hydrogen direct-fired unit, and the outlet of the hydrogen direct-fired unit is connected to the inlet of the compressed CO2 energy storage unit. The outlet of the compressed CO2 energy storage unit is connected to the inlet of the hydrogen direct-fired unit. The compressed CO2 energy storage unit includes at least two CO2 compression devices, and each CO2 compression device is equipped with an interstage heat exchanger.

[0007] This invention replaces the high-pressure gaseous hydrogen storage system with a solid-state hydrogen storage unit to store a large amount of hydrogen, significantly improving the safety of the hydrogen storage system, reducing the safety risk level and regulatory requirements of the entire hydrogen storage system, and allowing daily operations to focus more on the production process itself.

[0008] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0009] As a preferred embodiment of the present invention, the solid hydrogen storage unit includes a hydrogen storage device loaded with solid hydrogen storage material.

[0010] Preferably, the solid hydrogen storage material includes any one of titanium-manganese hydrogen storage materials, vanadium hydrogen storage materials, or rare earth hydrogen storage materials, with titanium-manganese hydrogen storage materials being the most preferred.

[0011] As a preferred embodiment of the present invention, the hydrogen direct combustion unit includes a combustion chamber, a high-pressure gas turbine, and a low-pressure gas turbine connected in sequence.

[0012] As a preferred embodiment of the present invention, the at least two-stage CO2 compression device includes a first-stage CO2 compressor and a second-stage CO2 compressor unit.

[0013] Preferably, the compression ratio of the first stage CO2 compressor is 6 to 12, and the compression ratio of the second stage CO2 compressor unit is 10 to 11.

[0014] As a preferred technical solution of the present invention, the heat recovered by the interstage heat exchanger of the first stage compressor is used for CO2 preheating before entering the hydrogen direct combustion unit.

[0015] Preferably, the heat recovered by the interstage heat exchanger of the second-stage CO2 compressor unit is used as the heat source for hydrogen release in the solid-state hydrogen storage unit.

[0016] This invention utilizes the waste heat from the direct combustion of hydrogen to compress CO2 to heat solid hydrogen storage materials, eliminating the need for additional heating systems such as electric heaters. This simplifies the composition of the solid hydrogen storage unit, reduces initial investment, improves project economics, and enhances overall system efficiency. Furthermore, the waste heat from different compression stages is specifically allocated: the high-temperature waste heat generated by the heat exchanger of the first-stage CO2 compressor is used to preheat the material entering the direct combustion hydrogen unit; the medium-to-low-temperature waste heat generated by the heat exchanger of the second-stage CO2 compressor unit is directly supplied to the solid hydrogen storage unit as a heat source for hydrogen release, eliminating the need for additional external energy consumption.

[0017] As a preferred embodiment of the present invention, the compressed CO2 energy storage unit further includes a flue gas regenerator, which is connected to the outlet of the hydrogen direct combustion unit and is used to recover the heat of the flue gas after combustion and the compression heat of the first stage compressor.

[0018] As a preferred technical solution of the present invention, the inlet of the compressed CO2 energy storage unit is also provided with a water removal device and a low-pressure CO2 gas bag, and the flue gas from the outlet of the hydrogen direct combustion unit enters the low-pressure CO2 gas bag for storage after water removal.

[0019] Preferably, the water removal device includes a condenser.

[0020] As a preferred technical solution of the present invention, the compressed CO2 energy storage unit includes a liquid CO2 storage tank, and the CO2 compressed by the at least two compression devices enters the liquid CO2 storage tank for storage.

[0021] Preferably, a compressed CO2 cooler is installed in front of the liquid CO2 storage tank.

[0022] As a preferred embodiment of the present invention, the inlet of the hydrogen direct combustion unit is also connected to an oxygen supply device.

[0023] As a preferred technical solution of the present invention, the heat exchange medium of the interstage heat exchanger of the first stage compressor exchanges heat with the solid hydrogen storage unit and then circulates back to the interstage heat exchanger.

[0024] Preferably, the heat exchange medium of the interstage heat exchanger of the first stage compressor adopts a counter-current heat exchange method in the interstage heat exchanger.

[0025] Preferably, the heat exchange medium returned from the solid hydrogen storage unit and the flue gas regenerator is cooled to a preset temperature by a pre-cooling device before entering the interstage heat exchanger.

[0026] The preset temperature described in this invention can be selected and optimized according to the material cooling requirements of the system, and is not further limited here.

[0027] The heat exchange medium described in this invention includes commonly used industrial heat exchange media such as circulating cooling water, which can be selected according to actual working conditions, and no further limitations are made here.

[0028] The operation mode of the hydrogen direct combustion compression CO2 energy storage system coupled with solid-state hydrogen storage described in this invention includes the following steps: (1) The solid hydrogen storage unit releases hydrogen, which is then burned with oxygen supplied by the oxygen supply device in the combustion chamber of the hydrogen direct combustion unit to produce high-temperature flue gas, which drives the high-pressure gas turbine and the low-pressure gas turbine to do work and generate electricity. After doing work, the flue gas recovers waste heat through the flue gas regenerator and removes water through the dewatering device. CO2 enters the low-pressure CO2 gas bag for temporary storage and then enters the compression device again to complete the cycle. (2) The compressed CO2 energy storage unit compresses CO2 in stages through a multi-stage compression device. Each stage of the compression device recovers the heat of compression through an interstage heat exchanger. The compressed CO2 is cooled and then stored in a liquid CO2 storage tank to complete the energy storage. (3) The interstage heat exchanger of the first stage compressor recovers high-temperature waste heat for CO2 preheating before entering the hydrogen direct combustion unit; the interstage heat exchanger of the second stage CO2 compressor recovers medium- and low-temperature waste heat to provide a heat source for the hydrogen release process of the solid hydrogen storage unit without the need for additional external energy consumption.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects: (1) This invention uses solid hydrogen storage to replace traditional high-pressure gaseous hydrogen storage, which greatly improves the safety of the hydrogen storage system, reduces the safety risk level and regulatory requirements of the system, and reduces the cost and manpower requirements of daily operation and maintenance. (2) The present invention uses the heat of CO2 compression to release hydrogen in the solid hydrogen storage process, realizes multi-level energy utilization, reduces the heat input from the outside, and thus improves the economy of the entire hydrogen storage system. Attached Figure Description

[0030] Figure 1 This is a flowchart of the hydrogen direct combustion compressed CO2 energy storage system provided in an embodiment of the present invention; In the diagram: 1-Titanium-manganese solid hydrogen storage unit, 2-Hydrogen direct combustion unit, 21-Combustion chamber, 22-High-pressure gas turbine, 23-Low-pressure gas turbine, 3-Compressed CO2 energy storage unit, 31-Flue gas regenerator, 32-Condenser, 33-Low-pressure CO2 gasbag, 34-First stage CO2 compressor, 35-Compressor interstage heat exchanger, 36-Second stage CO2 compressor unit, 37-Compressor interstage heat exchanger unit, 38-Compressed CO2 cooler, 39-Liquid CO2 storage tank, 310-Circulating cooling water heat exchanger, 311-Circulating cooling water heat exchanger. Detailed Implementation

[0031] To facilitate understanding of the present invention, the following embodiments are provided. Those skilled in the art should understand that these embodiments are merely illustrative and should not be construed as limiting the scope of the invention.

[0032] Example 1 This embodiment provides a hydrogen direct-fired compression CO2 energy storage system coupled with solid-state hydrogen storage. It employs a 380V low-voltage power distribution system, with a total auxiliary system power distribution capacity of approximately 750kW. Figure 1 As shown, the hydrogen direct combustion compressed CO2 energy storage system includes: Solid-state hydrogen storage unit 1, wherein the solid-state hydrogen storage unit 1 is filled with TiMn2 hydrogen storage alloy, and the hydrogen release rate is 40000 Nm. 3 / h, continuous hydrogen release time is about 8 hours, total hydrogen storage capacity is about 30,000 kg, and hydrogen pressure after hydrogen release reaction is about 1.6 MPa; hydrogen is stored by connecting to the green hydrogen of the new energy hydrogen production system through the hydrogen filling pipeline system, and hydrogen is supplied to the combustion chamber 21 by connecting to the hydrogen release pipeline system. The hydrogen direct combustion unit 2 includes a combustion chamber 21, a high-pressure gas turbine 22, and a low-pressure gas turbine 23 connected in sequence. O2 produced by hydrogen electrolysis is introduced into the combustion chamber 21 to supply oxygen for the combustion process. The green hydrogen consumption rate is 40,000 Nm³. 3 / h, combustion is completed in a CO2 environment, the power generation of the hydrogen direct combustion unit is about 100MW, and the generated combustion flue gas passes through the high-pressure gas turbine 22 and the low-pressure gas turbine 23 in sequence to do work. The high-temperature flue gas pressure discharged is close to atmospheric pressure. The compressed CO2 energy storage unit 3 includes a flue gas regenerator 31, a condenser 32, a low-pressure CO2 gas bag 33, a first-stage CO2 compressor 34, an interstage heat exchanger 35, a second-stage CO2 compressor unit 36, and an interstage heat exchanger unit 37 connected in sequence. Then, a compressed CO2 cooler 38 and a liquid CO2 storage tank 39 are connected in sequence. The heat exchange medium of the interstage heat exchangers is circulating water. A circulating cooling water heat exchanger 310 and a circulating cooling water heat exchanger 311 are also provided, located at the circulating water inlet respectively. The compression ratio of the first-stage CO2 compressor 34 is 6~7, and the compression ratio of the second-stage CO2 compressor unit 36 ​​is 10~11.

[0033] The solid hydrogen storage unit 1 and the hydrogen direct combustion unit 2 are directly connected through a hydrogen release pipeline system. The outlet of the low-pressure gas turbine 23 of the hydrogen direct combustion unit 2 is connected to the inlet of the flue gas regenerator 31 of the compressed CO2 energy storage unit 3. The outlet of the liquid CO2 storage tank 39 of the compressed CO2 energy storage unit 3 is connected to the flue gas regenerator 31. The CO2 preheated by the flue gas regenerator 31 is directly introduced into the combustion chamber 21 of the hydrogen direct combustion unit 2.

[0034] Example 2 This embodiment provides an operation mode for a hydrogen direct combustion compression CO2 energy storage system coupled with solid-state hydrogen storage as described in Embodiment 1: The green hydrogen produced by the new energy hydrogen production system is stored in the solid hydrogen storage unit 1 through the hydrogen charging pipeline system. During the energy release stage, the solid hydrogen storage unit 1 releases hydrogen gas, which is then transported to the combustion chamber 21 through the hydrogen release pipeline system.

[0035] In combustion chamber 21, hydrogen and O2 produced by hydrogen electrolysis are burned in a CO2 environment. The resulting combustion flue gas passes through high-pressure gas turbine 22 and low-pressure gas turbine 23 in sequence to generate electricity, with a power output of about 100MW. The high-temperature flue gas discharged after doing work has a pressure close to atmospheric pressure.

[0036] High-temperature flue gas enters flue gas regenerator 31 for waste heat recovery, and then passes through condenser 32 to cool to room temperature. Water vapor in the flue gas is condensed and liquefied and recovered. After removing water vapor, the remaining room temperature and pressure gaseous CO2 enters low-pressure gas storage bladder 33 for storage.

[0037] The first stage CO2 compressor 34 compresses and heats CO2 to about 195°C, and then cools it down to about 25°C through the interstage heat exchanger 35. The outlet temperature of the cooling water after cooling CO2 is 185°C and the flow rate is 300t / h. The second-stage CO2 compressor unit 36 ​​compresses and heats the CO2 to about 75°C, and then cools it down to about 25°C through the interstage heat exchanger unit 37. The inlet temperature of the circulating cooling water is 20°C, the outlet temperature is 65°C, and the flow rate is 1500t / h.

[0038] The second-stage CO2 compressor 36 compresses CO2 to 7MPa, and after being cooled to 25°C by the CO2 compressor cooler 38, it enters the liquid CO2 storage tank 39 for storage. The cooling medium is circulating cooling water with an inlet temperature of 20°C, an outlet temperature of 42°C, and a flow rate of 2800t / h.

[0039] The 185°C circulating cooling water is used to heat the low-temperature CO2 in the flue gas regenerator 31, so that it is heated before entering the combustion chamber. After releasing heat, it is cooled to 45°C and returned to the circulating cooling water heat exchanger 311 to be cooled to 20°C for reuse. The 65°C circulating cooling water provides a heat source for the hydrogen release process of the solid hydrogen storage unit 1. After releasing heat, it is cooled to 60°C and returned to the circulating cooling water heat exchanger 310 to be cooled to 20°C for reuse. The CO2 stored in the liquid CO2 storage tank 39 is preheated by the flue gas regenerator 31 and then circulated into the combustion chamber 21 to complete the closed-loop operation.

[0040] In summary, this invention couples solid-state hydrogen storage with a direct-fired hydrogen compression CO2 energy storage system. It utilizes the high hydrogen storage density and low-risk characteristics of solid-state hydrogen storage materials to replace traditional high-pressure gaseous hydrogen storage. At the same time, it achieves efficient energy recovery and utilization through multi-stage CO2 compression and cascade heat exchange. Under the premise of ensuring long-term continuous and stable operation of the direct-fired hydrogen unit, it significantly reduces the safety risks of the hydrogen storage process, improves the overall energy utilization efficiency of the energy storage system, and provides a safe and efficient adjustable energy supply.

[0041] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A hydrogen direct-fired compressed CO2 energy storage system coupled with solid-state hydrogen storage, characterized in that, The hydrogen direct combustion compressed CO2 energy storage system coupled with solid-state hydrogen storage includes: a solid-state hydrogen storage unit, a hydrogen direct combustion unit, and a compressed CO2 energy storage unit. The solid-state hydrogen storage unit is connected to the inlet of the hydrogen direct combustion unit, and the outlet of the hydrogen direct combustion unit is connected to the inlet of the compressed CO2 energy storage unit. The outlet of the compressed CO2 energy storage unit is connected to the inlet of the hydrogen direct combustion unit. The compressed CO2 energy storage unit includes at least two CO2 compression devices, and each CO2 compression device is equipped with an interstage heat exchanger.

2. The hydrogen direct combustion compressed CO2 energy storage system according to claim 1, characterized in that, The solid-state hydrogen storage unit includes a hydrogen storage device loaded with solid-state hydrogen storage material. Preferably, the solid hydrogen storage material includes any one of titanium-manganese hydrogen storage materials, vanadium hydrogen storage materials, or rare earth hydrogen storage materials, with titanium-manganese hydrogen storage materials being the most preferred.

3. The hydrogen direct-fired compressed CO2 energy storage system according to claim 1 or 2, characterized in that, The hydrogen direct combustion unit includes a combustion chamber, a high-pressure gas turbine, and a low-pressure gas turbine connected in sequence.

4. The hydrogen direct-fired compressed CO2 energy storage system according to any one of claims 1 to 3, characterized in that, The at least two-stage CO2 compression device includes a first-stage CO2 compressor and a second-stage CO2 compressor unit; Preferably, the compression ratio of the first stage CO2 compressor is 6 to 12, and the compression ratio of the second stage CO2 compressor unit is 10 to 11.

5. The hydrogen direct combustion compressed CO2 energy storage system according to claim 4, characterized in that, The heat recovered by the interstage heat exchanger of the first-stage CO2 compressor is used for CO2 preheating before entering the hydrogen direct combustion unit. Preferably, the heat recovered by the interstage heat exchanger of the second-stage CO2 compressor unit is used as the heat source for hydrogen release from the solid-state hydrogen storage unit.

6. The hydrogen direct-fired compressed CO2 energy storage system according to any one of claims 1 to 5, characterized in that, The compressed CO2 energy storage unit also includes a flue gas regenerator, which is connected to the outlet of the hydrogen direct combustion unit and is used to recover the heat of the flue gas after combustion to preheat the CO2 before it enters the hydrogen direct combustion unit.

7. The hydrogen direct-fired compressed CO2 energy storage system according to any one of claims 1 to 6, characterized in that, The inlet of the compressed CO2 energy storage unit is also equipped with a water removal device and a low-pressure CO2 gas bag. The flue gas from the outlet of the hydrogen direct combustion unit is stored in the low-pressure CO2 gas bag after water removal. Preferably, the water removal device includes a condenser.

8. The hydrogen direct-fired compressed CO2 energy storage system according to any one of claims 1 to 7, characterized in that, The compressed CO2 energy storage unit includes a liquid CO2 storage tank, and the CO2 compressed by the at least two compression devices is stored in the liquid CO2 storage tank. Preferably, a compressed CO2 cooler is installed in front of the liquid CO2 storage tank.

9. The hydrogen direct combustion compressed CO2 energy storage system according to any one of claims 1 to 8, characterized in that, The inlet of the hydrogen direct combustion unit is also connected to an oxygen supply device.

10. The hydrogen direct combustion compressed CO2 energy storage system according to any one of claims 1 to 9, characterized in that, The heat exchange medium of the interstage heat exchanger exchanges heat with the solid hydrogen storage unit and / or the flue gas regenerator and then circulates back to the interstage heat exchanger. Preferably, the heat exchange medium adopts a counter-current heat exchange method in the interstage heat exchanger; Preferably, the heat exchange medium returning from the solid hydrogen storage unit and the flue gas regenerator is cooled to a preset temperature by a pre-cooling device before entering the interstage heat exchanger.

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