Hydrogen energy storage system based on waste heat utilization and control method thereof

Abstract

The present invention discloses a hydrogen energy storage system based on waste heat utilization and a control method thereof. The system includes: an electrolytic hydrogen production subsystem; a fuel cell subsystem; a solid-state hydrogen storage subsystem; a waste heat supply subsystem; and a waste heat utilization loop. In the hydrogen charging state, the heat exchange medium in the waste heat utilization loop releases heat and cools down from the waste heat supply subsystem, flows to the electrolytic hydrogen production subsystem and the solid-state hydrogen storage subsystem to absorb heat, and then flows to the fuel cell subsystem and the waste heat supply subsystem in sequence to release heat. In the hydrogen discharge state, the heat exchange medium in the waste heat utilization loop releases heat and cools down from the waste heat supply subsystem, flows to the fuel cell subsystem to absorb heat, and then flows to the electrolytic hydrogen production subsystem and the solid-state hydrogen storage subsystem to release heat. The present invention can realize the recovery and utilization of internal waste heat, and realize the complementary cooling and heating requirements of different subsystems, reduce energy loss, improve efficiency, and realize the spatiotemporal transfer of electricity and heat.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen energy storage, and in particular to a hydrogen energy storage system based on waste heat utilization and a control method thereof. Background Art

[0002] Renewable energy plays an irreplaceable role in mitigating global climate change and achieving sustainable development. In scenarios with a high proportion of renewable energy, the demand for energy storage will continue to grow. Hydrogen energy storage, as a long-term, large-scale energy storage option, can store and transfer renewable energy across seasons and spaces, compared to electrochemical energy storage. It is key to accommodating wind and solar power and stabilizing the power grid. Furthermore, hydrogen, as a clean energy source, offers zero emissions and pollution, high energy density, and a wide range of applications. Regarding power transmission, on the load side, there is a lack of million-kilowatt energy storage products with discharge times of 4 to 20 hours. Distributed hydrogen energy storage is a well-suited solution for this energy storage demand range. It can be coupled with distributed renewable energy sources such as distributed photovoltaics to alleviate the long-term imbalance between distributed photovoltaic output and the electricity load of industrial and commercial users, providing them with low-cost electricity and heat.

[0003] Hydrogen energy storage involves producing hydrogen through water electrolysis, which is then stored. When electricity is needed, hydrogen-oxygen fuel cells generate electricity, achieving both energy storage and transfer. Hydrogen energy storage involves multiple conversion steps, resulting in energy losses at each stage: the electrolysis cell, hydrogen storage, and fuel cell. The round-trip electrical efficiency is only 32.7%, constraining the development of hydrogen energy storage systems and necessitating an urgent need to improve their efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a hydrogen energy storage system based on waste heat utilization and a control method thereof, so as to solve the technical problems of large energy loss and low efficiency of the current hydrogen energy storage system.

[0005] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0006] The present invention provides a hydrogen energy storage system based on waste heat utilization, comprising: an electrolysis hydrogen production subsystem connected to the power system; a fuel cell subsystem connected to the power system; a solid-state hydrogen storage subsystem connected to the hydrogen output end of the electrolysis hydrogen production subsystem and the hydrogen input end of the fuel cell subsystem; a waste heat supply subsystem connected to the thermal supply system; a waste heat utilization circuit, wherein the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem are arranged in parallel on the waste heat utilization circuit, and the fuel cell subsystem and the waste heat supply subsystem are arranged in series on the waste heat utilization circuit; wherein The hydrogen energy storage system has a hydrogen charging state and a hydrogen degassing state; in the hydrogen charging state, the first heat exchange medium in the waste heat utilization circuit releases heat and cools down from the waste heat supply subsystem, then flows to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem to absorb heat, and after absorbing heat, flows to the fuel cell subsystem and the waste heat supply subsystem in turn to release heat; in the hydrogen degassing state, the first heat exchange medium in the waste heat utilization circuit releases heat and cools down from the waste heat supply subsystem, then flows to the fuel cell subsystem to absorb heat, and after absorbing heat, flows to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem to release heat.

[0007] In an embodiment of the present invention, the electrolytic hydrogen production mechanism includes an electrolytic stack and a gas-liquid separation structure, wherein the electrolytic stack is connected to the gas-liquid separation structure and is electrically connected to the power system;

[0008] The gas-liquid separation structure and / or the electrolytic stack is provided with a heat exchange channel, which is connected to the waste heat utilization circuit. The heat exchange medium in the waste heat utilization circuit can flow into the heat exchange channel to exchange heat with the electrolyte in the gas-liquid separation structure and / or the electrolytic stack.

[0009] In an embodiment of the present invention, the waste heat utilization circuit is provided with a first heat exchange control structure and a second heat exchange control structure, and the first heat exchange control structure and the second heat exchange control structure are located at both ends of the parallel connection of the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem;

[0010] The waste heat utilization circuit controls the flow of heat exchange medium respectively input into the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem through the first heat exchange control structure and the second heat exchange control structure.

[0011] In an embodiment of the present invention, a first heat exchange regulating bypass is connected between the first heat exchange control structure and the second heat exchange control structure, and the waste heat utilization loop controls the flow of the heat exchange medium input into the electrolysis hydrogen production subsystem, the solid-state hydrogen storage subsystem and the first heat exchange regulating bypass respectively through the first heat exchange control structure and the second heat exchange control structure.

[0012] In an embodiment of the present invention, a third heat exchange control structure and a fourth heat exchange control structure are provided on the waste heat utilization circuit. The third heat exchange control structure and the fourth heat exchange control structure are located at both ends of the series connection of the fuel cell subsystem. The waste heat utilization circuit controls the flow rate of the heat exchange medium input into the fuel cell subsystem through the third heat exchange control structure and the fourth heat exchange control structure.

[0013] In an embodiment of the present invention, a second heat exchange regulating bypass is connected between the third heat exchange control structure and the fourth heat exchange control structure, and the waste heat utilization loop inputs the flow rate of the heat exchange medium in the fuel cell subsystem and the second heat exchange regulating bypass through the third heat exchange control structure and the fourth heat exchange control structure respectively.

[0014] In an embodiment of the present invention, the waste heat supply subsystem includes a heat exchange circuit, an evaporator and a condenser are provided on the heat exchange circuit, the evaporator is connected to the waste heat utilization circuit, and the condenser is connected to the thermal supply system. The heat exchange medium in the waste heat utilization circuit can heat the heat exchange medium in the heat exchange circuit in the evaporator, and the heat exchange medium heated in the heat exchange circuit can heat the heat supply medium of the thermal supply system in the condenser.

[0015] In an embodiment of the present invention, a delivery pump is provided on the waste heat utilization circuit. The delivery pump controls the direction of rotation of the delivery pump to control the waste heat utilization circuit to have different flow directions in the hydrogen charging state and the hydrogen decompression state.

[0016] In an embodiment of the present invention, an auxiliary heater is provided on the waste heat utilization circuit, and the auxiliary heater is arranged in series between the electrolysis hydrogen production subsystem and the fuel cell subsystem.

[0017] The present invention also provides a control method for a hydrogen energy storage system, which is used to control the above-mentioned hydrogen energy storage system. The control method includes the following steps: controlling the operating state of the hydrogen energy storage system according to the power generation of the power generation side of the power system and the power consumption of the load side of the power system; wherein the operating state includes a hydrogen charging state and a hydrogen discharge state; when the power generation of the power generation side is greater than the power consumption of the load side, the operating state is controlled to be the hydrogen charging state; when the power generation of the power generation side is less than the power consumption of the load side, the operating state is controlled to be the hydrogen discharge state; according to the operating state, the hydrogen storage system is controlled to be in the hydrogen charging state. The flow direction of the waste heat utilization circuit; wherein, when the operating state is the hydrogen charging state, the heat exchange medium in the waste heat utilization circuit is controlled to release heat and cool down from the waste heat supply subsystem and then flow to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem to absorb heat, and after absorbing heat, it flows to the fuel cell subsystem and the waste heat supply subsystem in sequence to release heat; when the operating state is the hydrogen release state, the heat exchange medium in the waste heat utilization circuit is controlled to release heat and cool down from the waste heat supply subsystem and then flow to the fuel cell subsystem to absorb heat, and after absorbing heat, it flows to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem to release heat.

[0018] In an embodiment of the present invention, the operating state also includes a standby state. When the power generation on the power generation side is equal to the power consumption on the load side, the operating state is controlled to be the standby state. The control method also includes: when the operating state is the standby state, controlling the auxiliary heater to heat the heat exchange medium in the waste heat utilization circuit, and controlling the heated heat exchange medium to flow to the electrolysis hydrogen production subsystem and the fuel cell subsystem in sequence to release heat.

[0019] In an embodiment of the present invention, the control method further includes the following steps: controlling the flow rate of the heat exchange medium in the waste heat utilization loop flowing through the electrolysis hydrogen production subsystem, the solid-state hydrogen storage subsystem and / or the fuel cell subsystem, thereby controlling the amount of heat exchange between the heat exchange medium in the waste heat utilization loop and the electrolysis hydrogen production subsystem, the solid-state hydrogen storage subsystem and / or the fuel cell subsystem; controlling the flow rate of the heat exchange medium in the heat exchange loop in the waste heat supply subsystem, thereby controlling the amount of heat exchange between the heat exchange medium in the waste heat utilization loop and the heat exchange medium in the heat exchange loop.

[0020] The characteristics and advantages of the present invention are:

[0021] The hydrogen energy storage system based on waste heat utilization and the control method thereof of the present invention realize the comprehensive management of the electrolysis hydrogen production subsystem, the solid-state hydrogen storage subsystem and the fuel cell subsystem by setting up a waste heat utilization loop, thereby realizing the recovery and utilization of waste heat within the system, and realizing the complementarity of the cooling and heating requirements of different subsystems under different operating states within the system, reducing the energy loss of the system and improving efficiency. In addition, the excess waste heat is supplied to the thermal supply system through the waste heat supply subsystem, and the hydrogen storage energy is converted into electrical energy and supplied to the power system through the fuel cell subsystem, thereby realizing the temporal and spatial transfer of electricity and heat, and meeting the thermal load requirements of the thermal supply system and the electricity demand of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 Schematic diagram of the structure of a hydrogen energy storage system based on waste heat utilization in a hydrogen charging state in one embodiment of the present invention.

[0024] Figure 2 Schematic diagram of the structure of a hydrogen energy storage system based on waste heat utilization in a hydrogen release state in one embodiment of the present invention.

[0025] Figure 3 Schematic diagram of the structure of a hydrogen energy storage system based on waste heat utilization in a hydrogen charging state in another embodiment of the present invention.

[0026] Figure 4 Schematic diagram of the structure of a hydrogen energy storage system based on waste heat utilization in a hydrogen release state in another embodiment of the present invention.

[0027] In the picture:

[0028] 1. Electrolysis hydrogen production subsystem; 11. Electrolytic cell; 12. Oxygen separator; 13. Hydrogen separator; 14. DC power supply; 15. Drying and purification structure; 16. Electrolyte circulation pump; 17. Electrolyte circulation loop;

[0029] 2. Solid-state hydrogen storage subsystem;

[0030] 3. Fuel cell subsystem;

[0031] 4. Waste heat supply subsystem; 41. Heat exchange circuit; 42. Evaporator; 43. Condenser; 44. Compressor; 45. Expansion valve;

[0032] 5. Waste heat utilization circuit; 51. Main pipeline; 52. First delivery pipeline; 53. Second delivery pipeline; 54. Third delivery pipeline; 55. Fourth delivery pipeline; 56. Intermediate delivery pipeline; 57. First heat exchange regulation bypass; 58. Second heat exchange regulation bypass; 59. Delivery pump; 510. Auxiliary heater; 511. First heat exchange control structure; 512. Second heat exchange control structure; 513. Third heat exchange control structure; 514. Fourth heat exchange control structure;

[0033] 6. Heat supply system; 61. Heat absorption and storage circuit; 62. Heat storage tank;

[0034] 7. User. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Implementation Method 1

[0037] like Figure 1 and Figure 2 As shown, the present invention provides a hydrogen energy storage system based on waste heat utilization, comprising: an electrolytic hydrogen production subsystem 1, connected to the power system; a fuel cell subsystem 3, connected to the power system; a solid-state hydrogen storage subsystem 2, connected to the hydrogen output end of the electrolytic hydrogen production subsystem 1 and the hydrogen input end of the fuel cell subsystem 3; a waste heat supply subsystem 4, connected to a thermal supply system 6; a waste heat utilization loop 5, wherein the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 are arranged in parallel on the waste heat utilization loop 5, and the fuel cell subsystem 3 and the waste heat supply subsystem 4 are arranged in series on the waste heat utilization loop 5; wherein the hydrogen energy storage system has a hydrogen charging state and a hydrogen discharging state; as shown in FIG. Figure 1 As shown, in the hydrogen charging state, the heat exchange medium in the waste heat utilization loop 5 releases heat and cools down from the waste heat supply subsystem 4, then flows to the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 to absorb heat, and after absorbing heat, flows to the fuel cell subsystem 3 and the waste heat supply subsystem 4 in turn to release heat; in the hydrogen decomposition state, the heat exchange medium in the waste heat utilization loop 5 releases heat and cools down from the waste heat supply subsystem 4, then flows to the fuel cell subsystem 3 to absorb heat, and after absorbing heat, flows to the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 to release heat.

[0038] The hydrogen energy storage system based on waste heat utilization of the present invention realizes the comprehensive management of the electrolysis hydrogen production subsystem 1, the solid-state hydrogen storage subsystem 2 and the fuel cell subsystem 3 by setting up a waste heat utilization loop 5, thereby realizing the recovery and utilization of waste heat inside the system, and realizing the complementary cooling and heating requirements of different subsystems under different operating states in the system, reducing the energy loss of the system and improving efficiency. In addition, the excess waste heat is supplied to the thermal supply system 6 through the waste heat supply subsystem 4, and the hydrogen storage energy is converted into electrical energy to supply the power system through the fuel cell subsystem 3, thereby realizing the spatiotemporal transfer of electricity and heat, and meeting the thermal load requirements of the thermal supply system 6 and the electricity demand of the power system. Specifically, a delivery pump 59 is provided on the waste heat utilization loop 5, and the delivery pump 59 controls the waste heat utilization loop 5 to have different flow directions in the hydrogen filling state and the hydrogen discharge state by controlling the direction of its rotation. Among them, in the hydrogen filling state, the flow direction of the heat exchange medium in the waste heat utilization loop 5 is Figure 1 In the clockwise direction shown in FIG; in the hydrogen release state, the flow direction of the heat exchange medium in the waste heat utilization circuit 5 is Figure 2 Optionally, two delivery pumps 59 with different delivery directions are provided to provide delivery power in the hydrogen charging state and the hydrogen discharging state respectively.

[0039] like Figure 1 and Figure 2 As shown, in the embodiment of the present invention, the fuel cell subsystem 3 is electrically connected to the load side of the power system, and the electrolysis hydrogen production subsystem 1 is connected to the power generation side of the power system. The operating state of the hydrogen energy storage system is controlled according to the power generation on the power generation side of the power system and the power consumption on the load side of the power system; wherein, the operating state includes a hydrogen charging state and a hydrogen decompression state; when the power generation on the power generation side is greater than the power consumption on the load side, the operating state is controlled to be a hydrogen charging state; when the power generation on the power generation side is less than the power consumption on the load side, the operating state is controlled to be a hydrogen decompression state; the flow direction of the waste heat utilization loop 5 is controlled according to the operating state; wherein, when the operating state is a hydrogen charging state, the heat exchange medium in the waste heat utilization loop 5 is controlled to flow from the waste heat supply subsystem 4 to the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 after releasing heat and cooling, and then flow to the fuel cell subsystem 3 and the waste heat supply subsystem 4 in turn to release heat; when the operating state is a hydrogen decompression state, the heat exchange medium in the waste heat utilization loop 5 is controlled to flow from the waste heat supply subsystem 4 to the fuel cell subsystem 3 after releasing heat and cooling, and then flow to the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 to release heat.

[0040] The power system may be a distributed renewable energy power generation system, including but not limited to hydropower, wind power, biomass power, solar power, ocean power, and geothermal power. The hydrogen energy storage system of the present invention may also be a distributed hydrogen energy storage system. The present invention controls the operating state of the hydrogen energy storage system according to the power generation on the power generation side and the power consumption on the load side of the power system, so that the hydrogen energy storage system is adapted to the needs of the power system, which is conducive to achieving comprehensive energy management and improving energy utilization.

[0041] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the electrolysis hydrogen production subsystem 1 can be an alkaline electrolysis system or a proton exchange membrane (PEM) electrolysis system, including an electrolysis stack and an accessory system including a gas-liquid separation structure. The electrolysis stack is connected to the gas-liquid separation structure and is electrically connected to the power system. The gas-liquid separation structure and / or the electrolysis stack are provided with a heat exchange channel, which is connected to the waste heat utilization circuit 5. The heat exchange medium in the waste heat utilization circuit 5 can flow into the heat exchange channel to exchange heat with the electrolyte in the gas-liquid separation structure and / or the electrolysis stack. In the hydrogen charging state, water molecules undergo an electrochemical reaction in the electrolysis hydrogen production subsystem 1 to decompose into hydrogen and oxygen. The hydrogen is processed by the accessory system and then enters the solid-state hydrogen storage subsystem 2 for storage. In the hydrogen discharge state, the solid-state hydrogen storage subsystem 2 releases the stored hydrogen into the fuel cell subsystem 3. The fuel cell subsystem 3 converts the chemical energy of the hydrogen into electrical energy through the electrochemical reaction and supplies it to the power system.

[0042] like Figure 3 and Figure 4 As shown, in some embodiments of the present invention, the electrolysis hydrogen production subsystem 1 is an alkaline electrolysis system, the electrolysis stack includes an electrolytic cell 11, and the gas separation structure includes an oxygen separator 12 and a hydrogen separator 13. The electrolytic cell 11 is electrically connected to the power system through a DC power supply 14, and the electrolytic cell 11 is connected to the oxygen separator 12 through an anolyte output pipeline, and the electrolytic cell 11 is connected to the hydrogen separator 13 through a cathode electrolyte output pipeline, and the oxygen separator 12 and the hydrogen separator 13 are also connected to the electrolytic cell 11 through an electrolyte circulation loop 17. Figure 3 As shown, in the hydrogen charging state, the DC power supply 14 passes DC power into the electrolytic cell 11 filled with electrolyte, and water molecules undergo an electrochemical reaction on the electrodes of the electrolytic cell 11 to decompose hydrogen and oxygen, wherein the hydrogen is mixed with the cathode electrolyte (i.e., the electrolyte near the cathode side of the electrolytic cell 11) and enters the hydrogen separator 13. The separated hydrogen is dried and purified by the drying and purification structure 15 and then stored in the solid-state hydrogen storage subsystem 2. The oxygen is mixed with the anode electrolyte (i.e., the electrolyte near the anode side of the electrolytic cell 11) and enters the oxygen separator 12 for separation; Figure 4As shown, in the hydrogen release state, the solid-state hydrogen storage subsystem 2 releases the stored hydrogen into the fuel cell subsystem 3. The fuel cell subsystem 3 converts the chemical energy of the hydrogen into electrical energy through an electrochemical reaction and supplies it to the power system. An electrolyte circulation pump 16 is provided on the electrolyte circulation loop 17.

[0043] Specifically, the oxygen separator 12 is provided with a first heat exchange channel, and the hydrogen separator 13 is provided with a second heat exchange channel. The first and second heat exchange channels are connected to the waste heat utilization circuit 5. The heat exchange medium in the waste heat utilization circuit 5 can flow into the first and second heat exchange channels to exchange heat with the electrolyte in the oxygen separator 12 and hydrogen separator 13. The waste heat utilization circuit 5 includes a main line 51, a first delivery line 52 connecting the oxygen separator 12 and the main line 51, a second delivery line 53 connecting the hydrogen separator 13 and the main line 51, and an intermediate delivery line 56 connecting the hydrogen separator 13 and the oxygen separator 12. Because the flow direction of the waste heat utilization circuit 5 is different during the hydrogen charging and dehydrogenation states, the end of the waste heat supply subsystem 4 connected to the fuel cell subsystem 3 forms its input end during the hydrogen charging state and its output end during the hydrogen dehydrogenation state. The end of the waste heat supply subsystem 4 connected to the solid-state hydrogen storage subsystem 2 and the electrolytic hydrogen production subsystem 1 forms its output end during the hydrogen charging state and its input end during the hydrogen dehydrogenation state. The waste heat utilization loop 5 further includes a third delivery pipeline 54 and a fourth delivery pipeline 55 , and the solid-state hydrogen storage subsystem 2 is connected to the main pipeline 51 via the third delivery pipeline 54 and the fourth delivery pipeline 55 .

[0044] like Figure 1 and Figure 2 As shown, the solid-state hydrogen storage subsystem 2 uses metals and metal alloys to form metal hydrides with hydrogen to achieve hydrogen storage. It has high hydrogen storage density and good safety performance. The process of hydrogen adsorption is accompanied by a large amount of heat release, and the process of hydrogen release requires heat absorption to achieve thermal hydrogen release.

[0045] like Figure 1 and Figure 2 As shown, the fuel cell subsystem 3 includes a fuel cell stack, a hydrogen supply structure, an air supply structure, a hydrothermal management structure, and other components, capable of converting the chemical energy of hydrogen into electrical energy. The fuel cell stack is provided with a heat exchange channel that communicates with the waste heat utilization circuit 5, allowing the heat exchange medium within the waste heat utilization circuit 5 to flow through the heat exchange channel and exchange heat with the fuel cell stack. The more specific structure of the fuel cell subsystem 3 can be found in the prior art and will not be further described here.

[0046] The present invention utilizes the waste heat utilization loop 5. In the hydrogen charging state, the heat generated by the electrolytic hydrogen production subsystem 1 during the electrolytic hydrogen production process and the heat generated by the solid-state hydrogen storage subsystem 2 during the hydrogen storage process are recovered by the heat exchange medium. The recovered heat is first used in the fuel cell subsystem 3 for heating and heat preservation. The remaining heat is then absorbed by the waste heat supply subsystem 4 and transmitted to the thermal system to realize the supply of heat. When hydrogen discharge is required for power supply, the solid-state hydrogen storage system releases hydrogen to the fuel cell subsystem 3 in the heat preservation environment to react and convert it into electrical energy for power supply. The fuel cell subsystem 3 Maintaining a suitable temperature is conducive to improving the energy conversion efficiency. After the reaction, the heat generated by the reaction of the fuel cell subsystem 3 is recovered by using a heat exchange medium. The recovered heat is then first used to heat and insulate the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2. The remaining heat is then absorbed by the waste heat supply subsystem 4 and transmitted to the thermal system to realize the supply of heat. The solid-state hydrogen storage subsystem 2 can then continuously absorb heat and release hydrogen at a stable rate. When hydrogen production and filling are required, the electrolytic hydrogen production subsystem 1 in a thermal insulation environment can also have a lower electrolysis voltage, thereby improving the hydrogen production efficiency.

[0047] In the present invention, the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 are arranged in parallel, and in the hydrogen charging state, the heat of the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 can be recovered respectively according to the different heat production conditions of the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 and the heat demand of the fuel cell subsystem 3; and in the hydrogen degassing state, heat can be provided to the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 respectively according to the different heat demand of the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 and the heat production condition of the fuel cell subsystem 3, thereby facilitating the complementarity of the cold and heat demands within the system.

[0048] like Figure 1 and Figure 2As shown, in order to facilitate the adjustment of the heat exchange amount between the heat exchange medium in the waste heat utilization loop 5 and the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, in some embodiments of the present invention, the waste heat utilization loop 5 is provided with a first heat exchange control structure 511 and a second heat exchange control structure 512, and the first heat exchange control structure 511 and the second heat exchange control structure 512 are located at the parallel ends of the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2; wherein, the waste heat utilization loop 5 controls the flow rate of the heat exchange medium flowing through the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 respectively through the first heat exchange control structure 511 and the second heat exchange control structure 512. By reasonably adjusting the flow rate of the heat exchange medium flowing through the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, the cooling needs of the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 are met at the same time in the hydrogen charging state; while in the hydrogen decomposition state, the heat exchange medium after absorbing heat is controlled to flow into the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 in different proportions according to the heat generation of the fuel cell subsystem 3, thereby meeting the heat needs of the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 at the same time.

[0049] like Figure 1 and Figure 2 As shown, in order to better regulate the heat exchange amount between the heat exchange medium in the waste heat utilization loop 5 and the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, in other embodiments of the present invention, a first heat exchange regulation bypass 57 is connected between the first heat exchange control structure 511 and the second heat exchange control structure 512, and the waste heat utilization loop 5 controls the flow rate of the heat exchange medium flowing through the electrolysis hydrogen production subsystem 1, the solid-state hydrogen storage subsystem 2 and the first heat exchange regulation bypass 57 respectively through the first heat exchange control structure 511 and the second heat exchange control structure 512. By adding the first heat exchange regulating bypass 57, in the hydrogen charging state, a portion of the heat exchange medium can be adjusted to flow into the first heat exchange regulating bypass 57 without absorbing heat from the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, and then mixed with the heat exchange medium after absorbing heat and then flowed to the fuel cell subsystem 1 together, thereby avoiding excessive cooling of the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, which causes the temperature of the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 to be too low; in the hydrogen degassing state, a portion of the heat exchange medium can be adjusted to flow into the first heat exchange regulating bypass 57 without heating and insulating the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, and then mixed with the heat exchange medium after heat release and then flowed to the waste heat supply subsystem 4 together, thereby avoiding excessive heat generation of the fuel cell subsystem 3, which causes the temperature of the heat exchange medium flowing into the electrolytic hydrogen production subsystem 1 and / or the solid-state hydrogen storage subsystem 2 to be too high, and more waste heat generated by the fuel cell subsystem 3 is absorbed by the waste heat supply subsystem 4, which is beneficial to improving the energy conversion efficiency of the system.

[0050] Specifically, the first heat exchange control structure 511 and the second heat exchange control structure 512 are both four-way proportional valves, which can realize the regulation of the flow rate of the heat exchange medium in the three parallel paths. Optionally, a control valve is set at both ends of the electrolysis hydrogen production subsystem 1 to realize the flow control of the heat exchange medium input into the electrolysis hydrogen production subsystem 1 and the flow control of the heat exchange medium output from the electrolysis hydrogen production subsystem 1; a control valve is set at both ends of the solid-state hydrogen storage subsystem 2 to realize the flow control of the heat exchange medium input into the solid-state hydrogen storage subsystem 2 and the flow control of the heat exchange medium output from the solid-state hydrogen storage subsystem 2; a control valve is set on the first heat exchange regulation bypass 57 to realize the control of the input flow rate and output flow rate of the heat exchange medium.

[0051] like Figure 1 and Figure 2 As shown, in order to facilitate regulation of the amount of heat exchange between the heat exchange medium in the waste heat utilization loop 5 and the fuel cell subsystem 3, in some embodiments of the present invention, the waste heat utilization loop 5 is provided with a third heat exchange control structure 513 and a fourth heat exchange control structure 514. The third heat exchange control structure 513 and the fourth heat exchange control structure 514 are located at the two ends of the series connection of the fuel cell subsystem 3. The waste heat utilization loop 5 controls the flow of the heat exchange medium through the fuel cell subsystem 3 via the third heat exchange control structure 513 and the fourth heat exchange control structure 514. By rationally regulating the flow of the heat exchange medium through the fuel cell subsystem 3 for heat exchange, the amount of heat exchange between the heat exchange medium and the fuel cell subsystem 3 is regulated. In the hydrogen charging state, the amount of heat exchange between the heat exchange medium and the fuel cell subsystem 3 after heat exchange through the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 is adapted to the heat demand of the fuel cell subsystem 3; while in the hydrogen depletion state, the amount of heat exchange between the heat exchange medium and the fuel cell subsystem 3 is adapted to the cooling demand of the fuel cell subsystem 3.

[0052] like Figure 1 and Figure 2As shown, in order to better regulate the heat exchange rate between the heat exchange medium in the waste heat utilization loop 5 and the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, in other embodiments of the present invention, a second heat exchange regulation bypass 58 is connected between the third heat exchange control structure 513 and the fourth heat exchange control structure 514, and the waste heat utilization loop 5 inputs the flow rate of the heat exchange medium in the fuel cell subsystem 3 and the second heat exchange regulation bypass 58 through the third heat exchange control structure 513 and the fourth heat exchange control structure 514 respectively. By adding a second heat exchange regulating bypass 58, in the hydrogen charging state, a part of the heat exchange medium after absorbing heat can be adjusted to flow into the second heat exchange regulating bypass 58 without heating and insulating the electrolytic hydrogen production subsystem 1, so as to mix with the heat exchange medium after releasing heat and then flow to the waste heat supply subsystem 4 together, thereby avoiding the temperature of the heat exchange medium flowing into the battery subsystem being too high due to the common high heat generation of the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2, and more of the waste heat generated by the electrolytic hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 is absorbed by the waste heat supply subsystem 4, which is beneficial to improving the energy conversion efficiency of the system; while in the hydrogen decompression state, a part of the heat exchange medium can be adjusted to flow into the second heat exchange regulating bypass 58 without absorbing the heat of the fuel cell subsystem 3, thereby avoiding the temperature of the fuel cell subsystem 3 being too low due to excessive cooling of the fuel cell subsystem 3.

[0053] Specifically, the second heat exchange regulating bypass 58 is arranged in parallel with the fuel cell subsystem 3, and the third heat exchange control structure 513 and the fourth heat exchange control structure 514 are both three-way proportional valves to realize the control of the input flow and output flow of the heat exchange medium in the two parallel paths.

[0054] In addition, if Figure 1 and Figure 2As shown, in the embodiment of the present invention, an auxiliary heater 510 is provided on the waste heat utilization circuit 5, and the auxiliary heater 510 is arranged in series between the electrolysis hydrogen production subsystem 1 and the fuel cell subsystem 3. By providing the auxiliary heater 510, on the one hand, when the system power is low and the waste heat is in short supply, the auxiliary heater 510 can be used to heat the heat exchange medium to achieve a balance between heat supply and demand in the system; on the other hand, in the standby state of the system (that is, the electrolysis hydrogen production subsystem 1, the solid-state hydrogen storage subsystem 2 and the fuel cell subsystem 3 are all not working), since the electrolysis hydrogen production subsystem 1 and the fuel cell subsystem 3 are all not working, the solid-state hydrogen storage subsystem 2 does not need to charge and discharge hydrogen, so the solid-state hydrogen storage subsystem 2 does not need to absorb and release heat, and the electrolysis hydrogen production subsystem 1 and the fuel cell subsystem 3 are both No waste heat is generated, so the waste heat supply subsystem 4 does not work. Therefore, the heat exchange medium is heated by the auxiliary heater 510. Since the operating temperature of the electrolysis hydrogen production subsystem 1 is generally higher than that of the fuel cell subsystem 3, the heated heat exchange medium is controlled to first flow into the electrolysis hydrogen production subsystem 1 for heating and insulation, and then flow to the fuel cell subsystem 3 for heating and insulation. In addition, by controlling the valve of the solid-state hydrogen storage subsystem 2 branch to be closed and the compressor 44 of the waste heat supply subsystem 4 to be inoperative, the heat exchange medium in the waste heat utilization loop 5 does not exchange heat with the solid-state hydrogen storage subsystem 2 and the waste heat supply subsystem 4.

[0055] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the waste heat supply subsystem 4 includes a heat exchange circuit 41, which is provided with an evaporator 42 and a condenser 43. The evaporator 42 is connected to the waste heat utilization circuit 5, and the condenser 43 is connected to the heat supply system 6. The heat exchange medium in the waste heat utilization circuit 5 can heat the heat exchange medium in the heat exchange circuit 41 in the evaporator 42, and the heated heat exchange medium in the heat exchange circuit 41 can heat the heat supply medium of the heat supply system 6 in the condenser 43. Specifically, the heat exchange circuit 41 is also provided with an expansion valve 45 and a compressor 44. The compressor 44 is located downstream of the evaporator 42, and the expansion valve 45 is located upstream of the evaporator 42. The expansion valve 45 is used to adjust the flow rate and pressure of the heat exchange medium in the heat exchange circuit 41, and the compressor 44 is used to compress the heat exchange medium after absorbing heat.

[0056] like Figure 1 and Figure 2As shown, in this embodiment, the heat exchange medium in the waste heat utilization circuit 5 is water. Of course, other liquids, gases, or gas-liquid mixtures can also be used as heat exchange media. The heat exchange medium in the heat exchange circuit 41 can be a refrigerant. Specifically, the heat supply medium of the heat supply system 6 is water, and the heat supply system 6 uses a heat absorption and storage circuit 61 to supply hot water to the user 7. The heat absorption and storage circuit 61 is connected to the condenser 43, and a heat storage tank 62 is provided on the heat absorption and storage circuit 61. The water in the heat absorption and storage circuit 61 absorbs heat from the condenser 43 and is stored in the heat storage tank 62. The heat storage tank 62 supplies hot water to the user 7 according to the heat demand of the user 7.

[0057] Implementation Method 2

[0058] Combine Figure 1 and Figure 2 As shown, the present invention also provides a control method for a hydrogen energy storage system, which is used to control the hydrogen energy storage system. The specific structure, working principle and beneficial effects of the hydrogen energy storage system in this embodiment are the same as those in the first embodiment, and will not be repeated here.

[0059] The control method of the present invention includes the following steps: controlling the operating state of the hydrogen energy storage system according to the power generation on the power generation side of the power system and the power consumption on the load side of the power system; wherein the operating state includes a hydrogen charging state and a hydrogen decompression state; when the power generation on the power generation side is greater than the power consumption on the load side, the operating state is controlled to be a hydrogen charging state; when the power generation on the power generation side is less than the power consumption on the load side, the operating state is controlled to be a hydrogen decompression state; controlling the flow direction of the waste heat utilization loop 5 according to the operating state; wherein, when the operating state is the hydrogen charging state, controlling the heat exchange medium in the waste heat utilization loop 5 to release heat and cool down from the waste heat supply subsystem 4 to flow to the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 to absorb heat, and after absorbing heat, flow to the fuel cell subsystem 3 and the waste heat supply subsystem 4 in turn to release heat; when the operating state is the hydrogen decompression state, controlling the heat exchange medium in the waste heat utilization loop 5 to release heat and cool down from the waste heat supply subsystem 4 to flow to the fuel cell subsystem 3 to absorb heat, and after absorbing heat, flow to the electrolysis hydrogen production subsystem 1 and the solid-state hydrogen storage subsystem 2 to release heat.

[0060] In an embodiment of the present invention, the operating state also includes a standby state. When the power generation on the power generation side is equal to the power consumption on the load side, the operating state is controlled to be a standby state. The control method also includes: when the operating state is a standby state, controlling the auxiliary heater 510 to heat the heat exchange medium in the waste heat utilization loop 5, and controlling the heated heat exchange medium to flow to the electrolysis hydrogen production subsystem 1 and the fuel cell subsystem 3 in turn to release heat.

[0061] In an embodiment of the present invention, the control method further includes the following steps: controlling the flow rate of the heat exchange medium input into the electrolysis hydrogen production subsystem 1, the solid-state hydrogen storage subsystem 2 and / or the fuel cell subsystem 3 in the waste heat utilization loop 5, thereby controlling the heat exchange rate between the heat exchange medium in the waste heat utilization loop 5 and the electrolysis hydrogen production subsystem 1, the solid-state hydrogen storage subsystem 2 and / or the fuel cell subsystem 3; controlling the flow rate of the heat exchange medium in the heat exchange loop 41 in the waste heat supply subsystem 4, thereby controlling the heat exchange rate between the heat exchange medium in the waste heat utilization loop 5 and the heat exchange medium in the heat exchange loop 41.

[0062] The above descriptions are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A hydrogen energy storage system based on waste heat utilization, characterized in that: include: The electrolysis hydrogen production subsystem is connected to the power system; a fuel cell subsystem connected to the power system; a solid-state hydrogen storage subsystem connected to the hydrogen output end of the electrolysis hydrogen production subsystem and the hydrogen input end of the fuel cell subsystem; The waste heat supply subsystem is connected to the heat supply system; A waste heat utilization circuit, wherein the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem are arranged in parallel on the waste heat utilization circuit, and the fuel cell subsystem and the waste heat supply subsystem are arranged in series on the waste heat utilization circuit; Wherein, the hydrogen energy storage system has a hydrogen charging state and a hydrogen discharging state; in the hydrogen charging state, the heat exchange medium in the waste heat utilization circuit flows to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem respectively after releasing heat and cooling from the waste heat supply subsystem to absorb heat, and then flows to the fuel cell subsystem and the waste heat supply subsystem in sequence to release heat after absorbing heat; in the hydrogen discharging state, the heat exchange medium in the waste heat utilization circuit flows to the fuel cell subsystem after releasing heat and cooling from the waste heat supply subsystem to absorb heat, and then flows to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem respectively to release heat after absorbing heat; The waste heat utilization circuit is provided with a first heat exchange control structure and a second heat exchange control structure, and the first heat exchange control structure and the second heat exchange control structure are located at both ends of the parallel connection of the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem; wherein, the waste heat utilization circuit controls the flow rate of the heat exchange medium flowing through the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem respectively through the first heat exchange control structure and the second heat exchange control structure; A first heat exchange regulating bypass is connected between the first heat exchange control structure and the second heat exchange control structure, and the waste heat utilization circuit controls the flow of the heat exchange medium flowing through the electrolysis hydrogen production subsystem, the solid-state hydrogen storage subsystem and the first heat exchange regulating bypass respectively through the first heat exchange control structure and the second heat exchange control structure; The waste heat utilization circuit is provided with a third heat exchange control structure and a fourth heat exchange control structure, the third heat exchange control structure and the fourth heat exchange control structure are located at both ends of the series connection of the fuel cell subsystem, and the waste heat utilization circuit controls the flow rate of the heat exchange medium flowing through the fuel cell subsystem through the third heat exchange control structure and the fourth heat exchange control structure; A second heat exchange regulating bypass is connected between the third heat exchange control structure and the fourth heat exchange control structure, and the waste heat utilization loop flows through the fuel cell subsystem and the flow of the heat exchange medium in the second heat exchange regulating bypass through the third heat exchange control structure and the fourth heat exchange control structure respectively.

2. The hydrogen energy storage system according to claim 1, characterized in that: The electrolysis hydrogen production subsystem includes an electrolysis stack and a gas-liquid separation structure, wherein the electrolysis stack is connected to the gas-liquid separation structure and is electrically connected to the power system; The gas-liquid separation structure and / or the electrolytic stack is provided with a heat exchange channel, which is connected to the waste heat utilization circuit. The heat exchange medium in the waste heat utilization circuit can flow into the heat exchange channel to exchange heat with the electrolyte in the gas-liquid separation structure and / or the electrolytic stack.

3. The hydrogen energy storage system according to claim 1, characterized in that: The waste heat supply subsystem includes a heat exchange circuit, which is provided with an evaporator and a condenser. The evaporator is connected to the waste heat utilization circuit, and the condenser is connected to the thermal supply system. The heat exchange medium in the waste heat utilization circuit can heat the heat exchange medium in the heat exchange circuit in the evaporator, and the heat exchange medium heated in the heat exchange circuit can heat the heat supply medium of the thermal supply system in the condenser.

4. The hydrogen energy storage system according to claim 1, characterized in that: The waste heat utilization circuit is provided with a delivery pump, and the delivery pump controls the waste heat utilization circuit to have different flow directions in the hydrogen charging state and the hydrogen decompression state by controlling the rotation direction of the delivery pump.

5. The hydrogen energy storage system according to claim 1, characterized in that: An auxiliary heater is provided on the waste heat utilization circuit, and the auxiliary heater is arranged in series between the electrolysis hydrogen production subsystem and the fuel cell subsystem.

6. A method for controlling a hydrogen energy storage system, characterized in that: For controlling the hydrogen energy storage system according to any one of claims 1 to 5, the control method comprises the following steps: controlling the operating state of the hydrogen energy storage system according to the power generation on the power generation side of the power system and the power consumption on the load side of the power system; The operating state includes a hydrogen charging state and a hydrogen discharging state; when the power generation on the power generation side is greater than the power consumption on the load side, the operating state is controlled to be the hydrogen charging state; when the power generation on the power generation side is less than the power consumption on the load side, the operating state is controlled to be the hydrogen discharging state; controlling the flow direction of the waste heat utilization circuit according to the operating state; Among them, when the operating state is the hydrogen charging state, the heat exchange medium in the waste heat utilization circuit is controlled to release heat and cool down from the waste heat supply subsystem, and then flow to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem to absorb heat, and then flow to the fuel cell subsystem and the waste heat supply subsystem in turn to release heat after absorbing heat; when the operating state is the hydrogen desorption state, the heat exchange medium in the waste heat utilization circuit is controlled to release heat and cool down from the waste heat supply subsystem, and then flow to the fuel cell subsystem to absorb heat, and then flow to the electrolysis hydrogen production subsystem and the solid-state hydrogen storage subsystem to release heat after absorbing heat.

7. The control method according to claim 6, wherein: The operating state also includes a standby state, and when the power generation on the power generation side is equal to the power consumption on the load side, the operating state is controlled to be the standby state; The control method further includes: when the operating state is the standby state, controlling the auxiliary heater to heat the heat exchange medium in the waste heat utilization circuit, and controlling the heated heat exchange medium to flow to the electrolysis hydrogen production subsystem and the fuel cell subsystem in sequence to release heat.

8. The control method according to claim 6, wherein: The control method further comprises the following steps: Controlling the flow rate of the heat exchange medium in the waste heat utilization loop flowing through the electrolysis hydrogen production subsystem, the solid-state hydrogen storage subsystem and / or the fuel cell subsystem, thereby controlling the amount of heat exchange between the heat exchange medium in the waste heat utilization loop and the electrolysis hydrogen production subsystem, the solid-state hydrogen storage subsystem and / or the fuel cell subsystem; The flow rate of the heat exchange medium in the heat exchange circuit in the waste heat supply subsystem is controlled, thereby controlling the heat exchange amount between the heat exchange medium in the waste heat utilization circuit and the heat exchange medium in the heat exchange circuit.

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