Novel renewable energy hydrogen energy storage system and operation method thereof

Abstract

The invention provides a novel renewable energy hydrogen energy storage system and an operation method thereof. The hydrogen energy storage system comprises an energy storage cycle unit, an energy release cycle unit, a heat energy utilization unit and the like. The energy storage cycle and the energy release cycle of the system are mutually independent loops, the fuel cell and the gas turbine are utilized in the hydrogen energy storage system to supplement the generating capacity, cooling water is used as a heat exchange medium, heat generated in the operation process of the system is stored, and the energy storage cycle and the energy release cycle of the system are mutually independent loops. And the working capacity of high-pressure hydrogen in front of the expansion machine is improved by utilizing tail gas of the gas turbine and hot water generated by utilizing waste heat of equipment, and consumed power in the hydrogen compression process is recycled by utilizing the hydrogen expansion machine. According to the hydrogen energy storage system, conversion of electric energy, hydrogen energy and heat energy is achieved through multi-stage recovery and utilization of heat energy, the working state of the valve can be adjusted according to the load requirement of a power grid, the operation methods of the hydrogen fuel cell and the gas turbine are switched, and the response flexibility, the energy release power density and the energy circulation efficiency of the system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy storage, and in particular to a novel renewable energy hydrogen energy storage system. Background Art

[0002] At present, the proportion of global renewable energy generation is increasing year by year, and clean energy has become the theme of energy development. Among clean energy, wind power generation and solar power generation account for a high proportion of installed capacity. my country has a vast territory and rich wind and solar energy resources, but due to the influence of climate, geographical location and industrial construction development, there is a large amount of "wind and solar abandonment" in Northwest, North China and Northeast China. Hydrogen energy, as a clean and pollution-free secondary energy, has attracted attention from countries around the world. Hydrogen production by electrolysis of water has become a new way to solve the problem of renewable energy consumption. The principle of hydrogen production from renewable energy is to input excess power generation into the electrolyzer for electrolysis of water to produce hydrogen, and the produced hydrogen and oxygen are input into the gas storage tank after passing through the compressor, realizing the storage of electric energy into hydrogen energy. When the power generation of renewable energy is insufficient, hydrogen and oxygen are input into the hydrogen fuel cell, and the hydrogen is converted into electric energy and released through the hydrogen fuel cell. Through the conversion of "electricity-hydrogen-electricity", the energy storage and release cycle of renewable energy is realized, thereby improving the utilization rate of renewable energy. Summary of the invention

[0003] Aiming at the problems of poor adjustment flexibility, large heat loss and low energy conversion efficiency of renewable energy hydrogen energy storage system. The present invention couples hydrogen fuel cells, gas turbines, hydrogen expanders and other equipment in the renewable energy hydrogen energy storage system to achieve "electricity-heat-hydrogen energy" cogeneration, and can switch different power generation modes according to electricity demand. When the electricity demand is low, the hydrogen fuel cell is started to generate electricity, when the electricity demand is medium, the gas turbine is started to generate electricity, and when the electricity demand is high, the hydrogen fuel cell and the gas turbine are started to generate electricity simultaneously. In addition, the waste heat generated by the electrolyzer, compressor, hydrogen fuel cell, gas turbine and other equipment during the operation of the system is recovered and utilized in multiple stages, which improves the work capacity of hydrogen, saves energy consumption during the operation process, and makes the system have higher energy conversion efficiency.

[0004] A novel renewable energy hydrogen energy storage system, wherein the hydrogen energy storage system mainly comprises an energy storage circulation system and an energy release circulation system, a water purification tank, a hydrogen storage tank, an oxygen storage tank, a cold water tank, and a hot water tank.

[0005] Furthermore, the energy storage circulation system includes an electrolyzer, a first heat exchanger is arranged inside the electrolyzer, the clean water tank is connected to the electrolyzer through a first pump body, the first outlet of the electrolyzer is connected to the first inlet of the first hydrogen heat exchanger, the first outlet of the first hydrogen heat exchanger is connected to the inlet of the hydrogen compressor, the outlet of the hydrogen compressor is connected to the first inlet of the second hydrogen heat exchanger, and the first outlet of the second hydrogen heat exchanger is connected to the hydrogen storage tank.

[0006] Furthermore, the second outlet of the electrolyzer is connected to the first inlet of the first oxygen heat exchanger, the first outlet of the first oxygen heat exchanger is connected to the inlet of the oxygen compressor, the outlet of the oxygen compressor is connected to the first inlet of the second oxygen heat exchanger, and the first outlet of the second oxygen heat exchanger is connected to the oxygen storage tank.

[0007] Furthermore, the first outlet of the cold water tank is connected to one end of the second pump body, and the other end of the second pump body is divided into three pipelines. The first pipeline is connected to the hot water tank after flowing through the first heat exchanger inside the electrolyzer. The first valve is provided on the first pipeline. The second pipeline is connected to the second inlet of the first hydrogen heat exchanger and the second inlet of the first oxygen heat exchanger. The third pipeline is connected to the second inlet of the second hydrogen heat exchanger and the second inlet of the second oxygen heat exchanger. The second outlet of the first hydrogen heat exchanger, the second outlet of the first oxygen heat exchanger, the second outlet of the second hydrogen heat exchanger, and the second outlet of the second oxygen heat exchanger are all connected to the first inlet of the hot water tank.

[0008] Furthermore, the energy release cycle system includes a first hydrogen expander and a second hydrogen expander, the first outlet of the hydrogen storage tank is connected to the first inlet of the fourth hydrogen heat exchanger, the first outlet of the fourth hydrogen heat exchanger is connected to the air inlet of the first hydrogen expander, the first hydrogen expander is connected to the first generator, and the air outlet of the first hydrogen expander is connected to the first air inlet of the hydrogen fuel cell; the second outlet of the hydrogen storage tank is connected to the first inlet of the third hydrogen heat exchanger, the first outlet of the third hydrogen heat exchanger is connected to the air inlet of the second hydrogen expander, the second hydrogen expander is connected to the second generator, and the air outlet of the second hydrogen expander is connected to the combustion chamber.

[0009] Furthermore, a second valve is provided between the hydrogen storage tank and the third hydrogen heat exchanger, and a third valve is provided between the hydrogen storage tank and the fourth hydrogen heat exchanger.

[0010] Furthermore, the first outlet of the oxygen storage tank is connected to the second inlet of the hydrogen fuel cell, and the second outlet of the oxygen storage tank is connected to the combustion chamber; the outlet of the hydrogen fuel cell is connected to the first end of the three-way valve, the second end of the three-way valve is connected to the combustion chamber, the third end of the three-way valve is connected to the inlet of the hydrogen circulation pump, and the outlet of the hydrogen circulation pump is connected to the first air inlet of the hydrogen fuel cell.

[0011] Furthermore, the air outlet of the combustion chamber is connected to the air inlet of the gas turbine, and the air outlet of the gas turbine is respectively connected to the second inlet of the third hydrogen heat exchanger and the first inlet of the exhaust gas heat exchanger, the second outlet of the third hydrogen heat exchanger and the first outlet of the exhaust gas heat exchanger are both connected to the outside atmosphere for exhaust, and a fourth valve is arranged on the pipeline between the gas turbine and the exhaust gas heat exchanger; the gas turbine is connected to the third generator.

[0012] Furthermore, a second heat exchanger is provided inside the hydrogen fuel cell, the second outlet of the cold water tank is connected to one end of the second heat exchanger, the other end of the second heat exchanger is connected to the second inlet of the hot water tank, the third outlet of the cold water tank is connected to the second inlet of the exhaust gas heat exchanger, the second outlet of the exhaust gas heat exchanger is connected to the third inlet of the hot water tank, the outlet of the hot water tank is connected to one end of the third pump body, the other end of the third pump body is connected to the second inlet of the fourth hydrogen heat exchanger, and the second outlet of the fourth hydrogen heat exchanger is connected to the inlet of the cold water tank.

[0013] A novel working method of a renewable energy hydrogen energy storage system comprises the following steps:

[0014] S1. When the output power of wind power generation and photovoltaic power generation exceeds the power grid's absorption capacity, the energy storage system's energy storage cycle starts;

[0015] S2. When the output of wind power generation and photovoltaic power generation cannot meet the needs of the power grid, the energy storage system's energy release cycle starts;

[0016] S3. Providing excess heat energy from the hydrogen energy storage system to users for heating;

[0017] S4. Deliver excess hydrogen from the hydrogen energy storage system to the hydrogen refueling station.

[0018] Furthermore, S1 is specifically:

[0019] The excess electric energy of the wind turbine and the photovoltaic panel is connected to the electrolyzer, and the purified water is input into the electrolyzer through the first pump body. At the same time, the first valve is opened, and the cooling water flows into the first heat exchanger, the first hydrogen heat exchanger, the first oxygen heat exchanger, the second hydrogen heat exchanger and the second oxygen heat exchanger in the electrolyzer respectively; the water in the electrolyzer is converted into hydrogen and oxygen by electric energy, and the hydrogen enters the first hydrogen heat exchanger through the first outlet of the electrolyzer, and the hydrogen exchanges heat with cold water in the first hydrogen heat exchanger. The hydrogen after cooling is input into the hydrogen compressor, and the hydrogen at room temperature and high pressure is converted into a high temperature and high pressure state after compression, and is input into the second hydrogen heat exchanger, and the hydrogen at high temperature and high pressure state exchanges heat with cold water in the second hydrogen heat exchanger, and is converted into a normal temperature and high pressure state and then input into the hydrogen storage tank for storage. The second outlet of the oxygen electrolyzer enters the first oxygen heat exchanger, and the oxygen exchanges heat with cold water in the first oxygen heat exchanger. The cooled oxygen is input into the oxygen compressor, and the oxygen at room temperature and high pressure is converted into a high temperature and high pressure state after compression, and is input into the second oxygen heat exchanger. The oxygen in the high temperature and high pressure state exchanges heat with cold water in the second oxygen heat exchanger, and is converted into a normal temperature and high pressure state before being input into the oxygen storage tank for storage.

[0020] When the first valve is opened, the second pump body inputs the cooling water in the cold water tank into the first heat exchanger in the electrolyzer, absorbs excess heat, and inputs the hot water after heat exchange into the heat storage tank for storage. The second pump body pumps the other part of the cooling water to the first hydrogen heat exchanger, the first oxygen heat exchanger, the second hydrogen heat exchanger, and the second oxygen heat exchanger, respectively, and uses the cooling water to exchange heat with hydrogen and oxygen to absorb the waste heat of hydrogen and oxygen. The hot water after heat exchange is input into the heat storage tank from the hot water outlets of the first hydrogen heat exchanger, the first oxygen heat exchanger, the second hydrogen heat exchanger, and the second oxygen heat exchanger for storage.

[0021] Furthermore, S2 is specifically:

[0022] S21. When the grid is in low load demand, the third valve is opened, and hydrogen is input into the fourth hydrogen heat exchanger. At the same time, the hot water in the heat storage tank also flows into the fourth hydrogen heat exchanger through the third pump body. The hydrogen is heated by the high-temperature water, and the high-temperature hydrogen is input into the first hydrogen expander to expand and do work, and the mechanical energy is converted into electrical energy through the first generator. The expanded hydrogen and the oxygen in the oxygen storage tank are input into the hydrogen fuel cell, and the hydrogen that has not been completely reacted in the hydrogen fuel cell is input into the hydrogen fuel cell again through the three-way valve and the hydrogen circulation pump.

[0023] S22. When the grid is in medium load demand, the second valve is opened, hydrogen is input into the third hydrogen heat exchanger and heated by the exhaust gas of the gas turbine, the high-temperature hydrogen is input into the second hydrogen expander to expand and do work, and the mechanical energy is converted into electrical energy through the second generator. The expanded hydrogen, oxygen in the oxygen storage tank and air in the environment are input into the combustion chamber, and hydrogen and oxygen are input into the gas turbine after combustion. The high-temperature and high-pressure gas expands and does work in the gas turbine, and the mechanical energy is converted into electrical energy through the third generator. Part of the exhaust gas of the gas turbine is used to heat hydrogen, and the other part is used to exchange heat with cooling water through the exhaust heat exchanger to generate high-temperature hot water, and the high-temperature hot water is input into the hot water tank for storage.

[0024] S23. When the grid is under high load demand, the second valve and the third valve are opened at the same time, and hydrogen is input into the gas turbine and the hydrogen fuel cell in two ways. The system supplements the power generation through the gas turbine and the hydrogen fuel cell. In addition, the hydrogen that is not completely reacted in the hydrogen fuel cell will be input into the combustion chamber through the three-way valve, and will no longer be input into the hydrogen fuel cell through the hydrogen circulation pump.

[0025] Furthermore, S3 is specifically:

[0026] When the energy release cycle starts, the high-temperature hot water in the heat storage tank is used to heat the hydrogen in the fourth hydrogen heat exchanger through the third pump body. After the high-temperature hot water exchanges heat with the hydrogen, it is input into the cold water tank from the cold water outlet of the fourth hydrogen heat exchanger. Part of the cooling water in the cold water tank is input into the hydrogen fuel cell to absorb the waste heat to prevent the hydrogen fuel cell from overheating; the other part of the cooling water is input into the exhaust heat exchanger to absorb the waste heat of the exhaust gas and recover the heat in the exhaust gas. After the heat exchange, the cooling water is input into the hot water tank for storage, and the high-temperature hot water is used to provide heating to users at the appropriate time.

[0027] Furthermore, S4 is specifically:

[0028] When the energy storage cycle starts, in order to increase the energy storage capacity of the system, a portion of the hydrogen in the hydrogen storage tank can be transported to the hydrogen refueling station for user use.

[0029] Compared with the prior art, the present invention has the following beneficial technical effects:

[0030] 1. The present invention provides a novel renewable energy hydrogen energy storage system and its operation method, which stores the waste heat during the operation of the system, uses the exhaust gas of the gas turbine and the waste heat of the equipment to increase the temperature of the hydrogen before the expander, thereby improving the working capacity of the high-pressure hydrogen, and uses the hydrogen expander to recover the power consumed in the compression process, thereby saving the energy cost of the system.

[0031] 2. The present invention provides a novel renewable energy hydrogen energy storage system and its operating method, which can timely adjust the operating methods of hydrogen fuel cells and gas turbines according to the grid load demand through the working states of the second valve, the third valve and the three-way valve, thereby improving the response flexibility of the system and broadening the application range of the system energy release power.

[0032] 3. The present invention provides a novel renewable energy hydrogen energy storage system and its operation method, which uses cooling water as a heat exchange medium, realizes the mutual conversion of electrical energy, hydrogen energy and thermal energy through multi-stage recovery and utilization of waste heat from system electrolyzers, compressors, hydrogen fuel cells, gas turbines and other equipment, and improves the energy conversion efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The following is a flow chart of a novel renewable energy hydrogen energy storage system and its operation method in an embodiment of the present invention. The actual correspondence between the reference numbers and component names of the present invention is as follows:

[0034] 1. Water purification tank; 2. First pump body; 3. Electrolyzer; 4. First hydrogen heat exchanger; 5. First oxygen heat exchanger; 6. Hydrogen compressor; 7. Oxygen compressor; 8. Second hydrogen heat exchanger; 9. Second oxygen heat exchanger; 10. Hydrogen storage tank; 11. Oxygen storage tank; 12. Cold water tank; 13. Second pump body; 14. First valve; 15. Hot water tank; 16. Third pump body; 17. Second valve; 18. Third hydrogen heat exchanger; 1 9. Third valve; 20. Fourth hydrogen heat exchanger; 21. First hydrogen expander; 22. Second hydrogen expander; 23. Hydrogen fuel cell; 24. Hydrogen circulation pump; 25. Three-way valve; 26. Combustion chamber; 27. Gas turbine; 28. Fourth valve; 29. ​​Tail gas heat exchanger; 30. First generator; 31. Second generator; 32. Third generator; 33. Hydrogen refueling station; 34. Photovoltaic panels; 35. Wind turbine DETAILED DESCRIPTION

[0035] To make the technical solution of the present invention clearer and more specific, the present invention is described clearly and completely below in conjunction with the accompanying drawings. Any equivalent replacement of the technical features of the technical solution of the present invention by ordinary technicians in the field without creative work and any solution derived from conventional reasoning shall fall within the protection scope of the present invention.

[0036] Example 1

[0037] See also Figure 1 The invention relates to a novel renewable energy hydrogen energy storage system, which comprises an energy storage circulation system, an energy release circulation system, a water purification tank 1, a hydrogen storage tank 10, an oxygen storage tank 11, a cold water tank 12 and a hot water tank 15.

[0038] The energy storage circulation system includes an electrolyzer 3, a first heat exchanger is arranged inside the electrolyzer 3, the clean water tank 1 is connected to the electrolyzer 3 through a first pump body 2, the first outlet of the electrolyzer 3 is connected to the first inlet of the first hydrogen heat exchanger 4, the first outlet of the first hydrogen heat exchanger 4 is connected to the inlet of the hydrogen compressor 6, the outlet of the hydrogen compressor 6 is connected to the first inlet of the second hydrogen heat exchanger 8, and the first outlet of the second hydrogen heat exchanger 8 is connected to the hydrogen storage tank 10.

[0039] The second outlet of the electrolyzer 3 is connected to the first inlet of the first oxygen heat exchanger 5, the first outlet of the first oxygen heat exchanger 5 is connected to the inlet of the oxygen compressor 7, the outlet of the oxygen compressor 7 is connected to the first inlet of the second oxygen heat exchanger 9, and the first outlet of the second oxygen heat exchanger 9 is connected to the oxygen storage tank 11.

[0040] The first outlet of the cold water tank 12 is connected to one end of the second pump body 13, and the other end of the second pump body 13 is divided into three pipelines. The first pipeline is connected to the hot water tank 15 after flowing through the first heat exchanger inside the electrolyzer 3. The first valve 14 is provided on the first pipeline. The second pipeline is connected to the second inlet of the first hydrogen heat exchanger 4 and the second inlet of the first oxygen heat exchanger 5. The third pipeline is connected to the second inlet of the second hydrogen heat exchanger 8 and the second inlet of the second oxygen heat exchanger 9. The second outlet of the first hydrogen heat exchanger 4, the second outlet of the first oxygen heat exchanger 5, the second outlet of the second hydrogen heat exchanger 8 and the second outlet of the second oxygen heat exchanger 9 are all connected to the first inlet of the hot water tank 15.

[0041] The energy release cycle system includes a first hydrogen expander 21 and a second hydrogen expander 22. The first outlet of the hydrogen storage tank 10 is connected to the first inlet of the fourth hydrogen heat exchanger 20, the first outlet of the fourth hydrogen heat exchanger 20 is connected to the air inlet of the first hydrogen expander 21, the first hydrogen expander 21 is connected to the first generator 30, and the air outlet of the first hydrogen expander 21 is connected to the first air inlet of the hydrogen fuel cell 23; the second outlet of the hydrogen storage tank 10 is connected to the first inlet of the third hydrogen heat exchanger 18, the first outlet of the third hydrogen heat exchanger 18 is connected to the air inlet of the second hydrogen expander 22, the second hydrogen expander 22 is connected to the second generator 31, and the air outlet of the second hydrogen expander 22 is connected to the combustion chamber 26.

[0042] A second valve 17 is provided between the hydrogen storage tank 10 and the third hydrogen heat exchanger 18 , and a third valve 19 is provided between the hydrogen storage tank 10 and the fourth hydrogen heat exchanger 20 .

[0043] The first outlet of the oxygen storage tank 11 is connected to the second inlet of the hydrogen fuel cell 23, and the second outlet of the oxygen storage tank 11 is connected to the combustion chamber 26; the outlet of the hydrogen fuel cell 23 is connected to the first end of the three-way valve 25, the second end of the three-way valve 25 is connected to the combustion chamber 26, the third end of the three-way valve 25 is connected to the inlet of the hydrogen circulation pump 24, and the outlet of the hydrogen circulation pump 24 is connected to the first air inlet of the hydrogen fuel cell 23.

[0044] The air outlet of the combustion chamber 26 is connected to the air inlet of the gas turbine 27, and the air outlet of the gas turbine 27 is respectively connected to the second inlet of the third hydrogen heat exchanger 18 and the first inlet of the exhaust gas heat exchanger 29. The second outlet of the third hydrogen heat exchanger 18 and the first outlet of the exhaust gas heat exchanger 29 are both connected to the outside atmosphere for exhaust. A fourth valve 28 is provided on the pipeline between the gas turbine 27 and the exhaust gas heat exchanger 29; the gas turbine 27 is connected to the third generator 32.

[0045] A second heat exchanger is provided inside the hydrogen fuel cell 23, the second outlet of the cold water tank 12 is connected to one end of the second heat exchanger, the other end of the second heat exchanger is connected to the second inlet of the hot water tank 15, the third outlet of the cold water tank 12 is connected to the second inlet of the exhaust gas heat exchanger 29, the second outlet of the exhaust gas heat exchanger 29 is connected to the third inlet of the hot water tank 15, the outlet of the hot water tank 15 is connected to one end of the third pump body 16, the other end of the third pump body 16 is connected to the second inlet of the fourth hydrogen heat exchanger 20, and the second outlet of the fourth hydrogen heat exchanger 20 is connected to the inlet of the cold water tank 12.

[0046] Example 2

[0047] A novel working method of a renewable energy hydrogen energy storage system comprises the following steps:

[0048] S1. When the output power of wind power generation and photovoltaic power generation exceeds the power grid's absorption capacity, the energy storage cycle of the energy storage system starts.

[0049] The excess electric energy of the wind turbine 35 and the photovoltaic panel 34 is connected to the electrolyzer 3, and the purified water is input into the electrolyzer 3 through the first pump body 2. At the same time, the first valve 14 is opened, and the cooling water flows into the first heat exchanger, the first hydrogen heat exchanger 4, the first oxygen heat exchanger 5, the second hydrogen heat exchanger 8 and the second oxygen heat exchanger 9 in the electrolyzer 3 respectively; the water in the electrolyzer 3 is electrolyzed into hydrogen and oxygen by electric energy, and the hydrogen enters the first hydrogen heat exchanger 4 through the first outlet of the electrolyzer 3, and the hydrogen exchanges heat with cold water in the first hydrogen heat exchanger 4, and the hydrogen after cooling is input into the hydrogen compressor 6, and the hydrogen at room temperature and high pressure is converted into a high temperature and high pressure state after compression, and is input into the second hydrogen heat exchanger 8, and the hydrogen at high temperature and high pressure state exchanges heat with cold water in the second hydrogen heat exchanger 8, and is converted into a normal temperature and high pressure state and input into the hydrogen storage tank 10 for storage. The second outlet of the oxygen electrolyzer 3 enters the first oxygen heat exchanger 5, and the oxygen exchanges heat with cold water in the first oxygen heat exchanger 5. The cooled oxygen is input into the oxygen compressor 7, and the oxygen at room temperature and high pressure is converted into a high temperature and high pressure state after compression, and is input into the second oxygen heat exchanger 9. The oxygen at high temperature and high pressure state exchanges heat with cold water in the second oxygen heat exchanger, and is converted into a normal temperature and high pressure state before being input into the oxygen storage tank 11 for storage.

[0050] During the energy storage process of the system, cooling water is used to absorb the waste heat of the equipment. The temperature of the electrolyzer 3 needs to be kept stable during operation. When the first valve 14 is opened, the second pump body 13 inputs the cooling water in the cold water tank 12 into the first heat exchanger in the electrolyzer 3 to absorb excess heat, prevent the electrolyzer 3 from over-temperature operation, and input the hot water after heat exchange into the heat storage tank 15 for storage. The second pump body 13 pumps another part of the cooling water to the first hydrogen heat exchanger 4, the first oxygen heat exchanger 5, the second hydrogen heat exchanger 8 and the second oxygen heat exchanger 9 respectively, and uses the cooling water to exchange heat with hydrogen and oxygen to absorb the waste heat of hydrogen and oxygen. The hot water after heat exchange is input into the heat storage tank 15 from the hot water outlets of the first hydrogen heat exchanger 4, the first oxygen heat exchanger 5, the second hydrogen heat exchanger 8 and the second oxygen heat exchanger 9 for storage.

[0051] S2. When the output power of wind power generation and photovoltaic power generation cannot meet the needs of the power grid, the energy release cycle of the energy storage system starts.

[0052] S21. When the power grid is in low load demand, the third valve 19 is opened, and hydrogen is input into the fourth hydrogen heat exchanger 20. At the same time, the hot water in the heat storage tank 15 also flows into the fourth hydrogen heat exchanger 20 through the third pump body 16. The hydrogen is heated by the high-temperature water, and the high-temperature hydrogen is input into the first hydrogen expander 21 to expand and do work, and the mechanical energy is converted into electrical energy through the first generator 30. The expanded hydrogen and the oxygen in the oxygen storage tank 11 are input into the hydrogen fuel cell 23, and the hydrogen that has not been completely reacted in the hydrogen fuel cell 23 is input into the hydrogen fuel cell 23 again through the three-way valve 25 and the hydrogen circulation pump 24.

[0053] S22. When the grid is in medium load demand, the second valve 17 is opened, hydrogen is input into the third hydrogen heat exchanger 18 and heated by the tail gas of the gas turbine 27, the high-temperature hydrogen is input into the second hydrogen expander 22 to expand and do work, and the mechanical energy is converted into electrical energy through the second generator 31. The expanded hydrogen, the oxygen in the oxygen storage tank 11 and the air in the environment are input into the combustion chamber 26, and the hydrogen and oxygen are input into the gas turbine 27 after combustion, the high-temperature and high-pressure gas expands and does work in the gas turbine, and the mechanical energy is converted into electrical energy through the third generator 32. A part of the tail gas of the gas turbine is used to heat the hydrogen, and the other part is used to exchange heat with cooling water through the tail gas heat exchanger 29 to generate high-temperature hot water, and the high-temperature hot water is input into the hot water tank 15 for storage.

[0054] S23. When the power grid is under high load demand, the second valve 17 and the third valve 19 are opened at the same time, and the hydrogen is input into the gas turbine 27 and the hydrogen fuel cell 23 in two ways, and the system supplements the power generation through the gas turbine 27 and the hydrogen fuel cell 23. In addition, the hydrogen that is not completely reacted in the hydrogen fuel cell 23 will be input into the combustion chamber 26 through the three-way valve 25, and the hydrogen will no longer be input into the hydrogen fuel cell through the hydrogen circulation pump 24.

[0055] S3. Providing excess heat energy from the hydrogen energy storage system to users for heating;

[0056] The energy release cycle of the hydrogen energy storage system requires the use of high-temperature hot water generated by the energy storage cycle. When the energy release cycle is started, the high-temperature hot water in the heat storage tank 15 is used to heat the hydrogen in the fourth hydrogen heat exchanger 20 through the third pump body 16. After heat exchange with the hydrogen, the high-temperature hot water is input into the cold water tank 12 from the cold water outlet of the fourth hydrogen heat exchanger 20. Part of the cooling water in the cold water tank 12 is input into the hydrogen fuel cell 23 to absorb waste heat to prevent the hydrogen fuel cell 13 from overheating; the other part of the cooling water is input into the exhaust gas heat exchanger 29 to absorb the waste heat of the exhaust gas and recover the heat in the exhaust gas. After heat exchange, the cooling water is input into the hot water tank 15 for storage, and the high-temperature hot water is used to provide heating to users at an appropriate time.

[0057] S4. Deliver excess hydrogen from the hydrogen energy storage system to the hydrogen refueling station

[0058] When the energy storage cycle is started, in order to increase the energy storage capacity of the system, a portion of the hydrogen in the hydrogen storage tank 10 is delivered to the hydrogen filling station 33 for use by users.

[0059] According to the power load demand of the power grid, the hydrogen energy storage system can operate the energy storage cycle mode during low power consumption, converting electrical energy into hydrogen energy for storage; the hydrogen energy storage system can operate the energy release cycle mode during peak power consumption, converting hydrogen energy into electrical energy for release. The heat generated by the system in the energy storage cycle and the energy release cycle is recovered and utilized through cooling water, realizing the provision of electricity, hydrogen energy, and heat energy to users.

Claims

1. A new type of renewable energy hydrogen energy storage system, characterized in that: The hydrogen energy storage system mainly comprises an energy storage circulation system and an energy release circulation system, a water purification tank (1), a hydrogen storage tank (10), an oxygen storage tank (11), a cold water tank (12), and a hot water tank (15).

2. A working method of the renewable energy hydrogen energy storage system as claimed in claim 1, characterized in that: The steps include: S1. When the output power of wind power generation and photovoltaic power generation exceeds the power grid's absorption capacity, the energy storage system's energy storage cycle starts; S2. When the output of wind power generation and photovoltaic power generation cannot meet the needs of the power grid, the energy storage system's energy release cycle starts; S3. Providing excess heat energy from the hydrogen energy storage system to users for heating; S4. Deliver excess hydrogen from the hydrogen energy storage system to the hydrogen refueling station.

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