Synergistic hydrogen-light-electricity-heat integrated comprehensive energy system and operation method

Abstract

The invention discloses a hydrogen-light-electricity-heat coordinated integrated comprehensive energy system and an operation method, the system adopts a power controller to carry out energy management on the system, when the load demand fluctuates, according to the set priority principle of system operation, the operation mode of the system is converted in real time, and coordination control of energy balance is carried out, so that the load demand is optimized. The reasonable distribution of the power can reduce the problem of light abandoning, the maximum utilization of energy is realized, the overall efficiency of the system is improved, and the system can better cope with the change of the load demand and stably operate for a long time. The system integrates photovoltaic power generation, fuel cell power generation, water electrolysis hydrogen production, energy storage, hydrogen storage and heat storage, complementation and supply and demand collaboration of various energy sources are achieved, the comprehensive energy efficiency of the system is improved, and various load requirements of electricity, hydrogen and heat can be met at the same time. Wherein the hydrogen is prepared by utilizing electric energy generated by photovoltaics, and in the process of producing green hydrogen by utilizing renewable energy sources, zero carbon emission is realized, and the utilization of clean energy sources is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of comprehensive energy utilization, and in particular relates to an integrated comprehensive energy system and an operation method of synergistic hydrogen-light-electricity-heat. Background Art

[0002] With energy shortages and increasingly severe environmental issues, the development and utilization of renewable energy has become a global focus. my country is accelerating the transformation and development of its energy sector. Electricity is a central component of this energy transition. China strongly supports the development of non-fossil energy sources such as photovoltaics, wind power, hydropower, and biomass, and encourages the construction of microgrids primarily focused on consuming renewable energy.

[0003] Currently, energy systems integrated with photovoltaic power generation face the following major challenges: First, due to the instability and intermittent nature of photovoltaic power generation, curtailment is a serious problem. Developing and effectively managing these systems to meet the diverse load demands of users over the long term while reducing curtailment and improving the overall energy efficiency of the system are pressing technical challenges. Furthermore, conventional energy management typically prioritizes excess photovoltaic power to the electrolyzer over energy storage batteries, while prioritizing fuel cells over energy storage batteries when photovoltaic power is insufficient. This approach presents challenges for energy storage batteries, which have limited capacity but fast response times, and fuel cells, which are limited only by hydrogen storage capacity but slow response times, and may result in inappropriate energy utilization or even waste. Furthermore, the efficiency of alkaline electrolyzers is approximately 70%, while that of proton exchange membrane fuel cells is approximately 45%. Both generate significant amounts of heat during operation, which is dissipated in various ways, such as exhaust gases and cooling water. This waste heat cannot be effectively utilized, resulting in energy waste. Furthermore, with China advocating the use of renewable energy and environmental protection, achieving large-scale grid connection while maintaining the greatest possible environmental protection remains a major challenge. Summary of the Invention

[0004] The purpose of the present invention is to provide an integrated comprehensive energy system and operation method that coordinates hydrogen, light, electricity and heat, which can reduce the problem of abandoned light, maximize the utilization of energy, improve the overall efficiency of the system, enable the system to better respond to changes in load system demand and operate stably in the long term.

[0005] The present invention is implemented as follows: an integrated energy system that coordinates hydrogen, light, electricity and heat, including a power controller, a photovoltaic array, an electrolyzer, a fuel cell, a compressor, a heat exchanger, a hydrogen condenser, an exhaust gas heat recovery device, an energy storage system, a power grid and a load system; wherein the energy storage system includes energy storage batteries, hydrogen storage bottles and heat storage tanks; the load system includes electricity users, heat users and hydrogen refueling machines;

[0006] The power controller is electrically connected to the photovoltaic array, the energy storage battery, the power grid, the electricity user, the fuel cell and the hydrogen storage bottle, and is used to monitor the power generation of the photovoltaic array, the load demand of the electricity user, the capacity status of the energy storage battery and the capacity status of the hydrogen storage bottle, so as to regulate the operation mode of the integrated comprehensive energy system in real time and achieve reasonable energy supply;

[0007] The power output end of the photovoltaic array is divided into three paths, which are respectively connected to the power user, the energy storage battery and the power input end of the electrolyzer;

[0008] The power input end of the electrolyzer is connected to the power output end of the photovoltaic array; the cooling water output end of the electrolyzer is connected to the heat input end of the heat exchanger, and the heat output end of the heat exchanger is connected to the heat input end of the heat storage tank; the hydrogen output end of the electrolyzer is connected to the hydrogen input end of the hydrogen condenser; the condensed water output end of the hydrogen condenser is connected to the heat input end of the heat storage tank; the hydrogen output end of the hydrogen condenser is connected to the hydrogen input end of the compressor, and the hydrogen output end of the compressor is connected to the hydrogen storage bottle, and the produced hydrogen is stored in the hydrogen storage bottle;

[0009] The hydrogen input end of the fuel cell is connected to the hydrogen output end of the hydrogen storage bottle; the power output end of the fuel cell is connected to the power input end of the electricity user; the high-temperature exhaust gas output end of the fuel cell is connected to the high-temperature exhaust gas input end of the exhaust gas heat recovery device, and the heat energy output end of the exhaust gas heat recovery device is connected to the heat energy input end of the heat storage tank; the cooling water output end of the fuel cell is connected to the heat energy input end of the heat exchanger, and the heat energy output end of the heat exchanger is connected to the heat energy input end of the heat storage tank;

[0010] The power input end of the electricity user is connected to the power output end of the photovoltaic array, the energy storage battery, the fuel cell, and the power grid respectively;

[0011] The power input end of the energy storage battery is connected to the power output end of the photovoltaic array; the power output end of the energy storage battery is connected to the power input end of the electricity user;

[0012] The hydrogen input end of the hydrogen storage bottle is connected to the hydrogen output end of the compressor; the hydrogen output end of the hydrogen storage bottle is divided into two paths, connected to the hydrogen input end of the fuel cell and the hydrogen refueling machine respectively;

[0013] The heat energy input end of the heat storage tank is divided into four paths, which are respectively connected to the tail gas heat recovery device, the hydrogen condenser and the heat energy output ends of the two heat exchangers; the heat energy output end of the heat storage tank is connected to the heat energy input end of the heat user.

[0014] To achieve the above-mentioned purpose, the present invention further provides an operation method of an integrated comprehensive energy system, which includes an energy management process:

[0015] When the electric load demand fluctuates, the power controller changes the system operation mode in real time based on the set system operation priority principle, taking the photovoltaic array power generation, energy storage battery capacity status and hydrogen storage tank capacity status as decision variables, and performs coordinated control of energy balance;

[0016] The system operation priority principles set in the power controller are as follows:

[0017] When there is excess photovoltaic power, the remaining photovoltaic power is distributed according to a predetermined ratio, and is supplied to energy storage batteries and electrolyzers at the same time for charging the energy storage batteries and producing hydrogen in the electrolyzers; if the energy storage batteries and hydrogen storage bottles are full, the surplus power is connected to the grid; when there is insufficient photovoltaic power, the energy storage batteries and fuel cells are jointly supplied with power according to a predetermined ratio to compensate for the remaining electrical load; if the capacity of both the energy storage batteries and hydrogen storage bottles is insufficient, electricity is purchased from the grid.

[0018] Furthermore, the factors determining the ratio include:

[0019] (1) The capacity configuration of electrolyzer, energy storage battery, and fuel cell;

[0020] (2) Light conditions in the area;

[0021] (3) The electricity, heat and hydrogen load in the area.

[0022] Furthermore, the system includes the following operating modes:

[0023] (1) When the power generated by the photovoltaic array is higher than the electric load demand and the capacity of the energy storage battery and the hydrogen storage tank are not full, the photovoltaic array supplies power to the electric load, and the power controller distributes the remaining photovoltaic power according to a predetermined ratio, part of which is used to charge the energy storage battery and the other part is used to produce hydrogen in the electrolyzer, and the produced hydrogen is stored to supply the fuel cell for power generation;

[0024] (2) When the power generated by the photovoltaic array is higher than the electric load demand, and the energy storage battery capacity is full and the hydrogen storage bottle capacity is not full, the photovoltaic array supplies power to the electric load, and the remaining power is transmitted to the electrolyzer;

[0025] (3) When the power generated by the photovoltaic array is higher than the electric load demand, and the hydrogen storage tank is full but the energy storage battery is not full, the photovoltaic array supplies power to the electric load, and the remaining power is transmitted to the energy storage battery;

[0026] (4) When the power generated by the photovoltaic array is higher than the electric load demand, and the energy storage battery and hydrogen storage tank are full, the photovoltaic array supplies power to the electric load, and the remaining power is transmitted to the grid;

[0027] (5) When the power generated by the photovoltaic array is equal to the power load demand, the photovoltaic array outputs power to the power load;

[0028] (6) When the power generation of the photovoltaic array is lower than the electric load demand, and both the fuel cell and the hydrogen storage bottle have surplus capacity, the photovoltaic array supplies power to part of the negative electric load, and the energy storage battery and the fuel cell jointly supply power to the remaining electric load in a predetermined ratio, with the energy storage battery compensating for part of the remaining electric load and the fuel cell compensating for the other part of the remaining electric load;

[0029] (7) When the power generation power of the photovoltaic array is lower than the electric load demand, and the capacity of the hydrogen storage bottle is insufficient and the energy storage battery has surplus capacity, the photovoltaic array and the energy storage battery will jointly supply the electric load;

[0030] (8) When the power generation of the photovoltaic array is lower than the electric load demand, and the energy storage battery capacity is insufficient and the hydrogen storage bottle capacity is surplus, the photovoltaic array and the fuel cell are combined to supply power to the electric load;

[0031] (9) When the power generation power of the photovoltaic array is lower than the electric load demand, and the capacity of the energy storage battery and the hydrogen storage bottle are insufficient, the photovoltaic array will supply power to a part of the electric load, and the remaining electric load will be supplied by the power grid.

[0032] Furthermore, the operating method also includes a hydrogen treatment process:

[0033] The hydrogen in the hydrogen storage tank has two uses: one is to provide fuel for fuel cell power generation; the other is to be used in a hydrogen refueling machine to refill hydrogen for fuel cell vehicles.

[0034] Furthermore, the operating method also includes a thermal energy treatment process:

[0035] For fuel cells, the high-temperature exhaust gas generated by the combustion of air and hydrogen in the fuel cell stack, as well as the high-temperature water mixed in it as a combustion product, are passed through the exhaust gas heat recovery device to transfer the heat to the heat medium. The heat generated by the fuel cell stack is carried away by the cooling water, which transfers the heat to the heat medium in the heat exchanger and is recycled. The heat medium then transfers the heat to the water in the heat storage tank to achieve thermal energy storage.

[0036] For the electrolyzer, the high-temperature hydrogen produced by the electrolysis of water is first passed into the hydrogen cooler for cooling, and the heat in the high-temperature hydrogen is taken away by the heat medium; the heat generated by the battery stack after reaching the rated temperature is taken away by the cooling water, and the cooling water transfers the heat to the heat medium in the heat exchanger and is recycled again; then the heat medium transfers the heat to the water in the heat storage tank to realize the storage of thermal energy.

[0037] Furthermore, the electrolytic cell is an alkaline electrolytic cell, and the chemical reaction in the electrolytic cell is: 2H2O→2H2+O2.

[0038] Furthermore, the fuel cell is a proton exchange membrane fuel cell, and the chemical reaction in the fuel cell is: O2+2H2→2H2O.

[0039] The integrated hydrogen-photovoltaic-electrical-thermal energy system and operation method provided by the present invention have the following advantages compared with the prior art:

[0040] This system uses a power controller for energy management. When load demand fluctuates, it changes the system's operating mode in real time, coordinating energy balance according to the established system operation priority principle, using the PV array power generation, the energy storage battery state of charge (SOC), and the hydrogen tank state of charge (SOH) as decision variables. While energy storage batteries have limited capacity but fast response speed, fuel cells are only limited by hydrogen storage capacity but have a slower response speed. Furthermore, while the energy conversion efficiency of the electrolyzer producing hydrogen for fuel cell power generation is relatively low, this approach offers the unique advantages of long-term, large-scale operation. The combination of these two methods can effectively cope with fluctuating load demands. Therefore, the priority principle sets the proportion of excess PV power transferred to the energy storage battery and electrolyzer, as well as the proportion of energy storage battery and fuel cell power generation to compensate for the remaining load when PV power is insufficient. This rational power allocation can reduce solar curtailment, maximize energy utilization, improve overall system efficiency, and enable the system to better cope with fluctuating load demands and maintain long-term stable operation.

[0041] This system integrates photovoltaic power generation, fuel cell power generation, water electrolysis hydrogen production, energy storage, hydrogen storage, and heat storage. The photovoltaic array, supplemented by fuel cells, energy storage batteries, and the power grid, meets the fluctuating load demands of electricity users, while the energy storage batteries and electrolyzers absorb excess photovoltaic power. Fuel cells have a slow dynamic response and cannot provide power for several hours continuously under sudden load changes. Energy storage batteries, on the other hand, have a fast dynamic response and can effectively compensate for power shortages caused by load changes. The system involves solar energy, hydrogen energy, electricity, and thermal energy, achieving complementary and coordinated supply and demand among multiple energy sources, effectively improving the system's overall energy efficiency and simultaneously meeting the demands of multiple loads: electricity, hydrogen, and heat. Then, the photovoltaic electricity is used to electrolyze water in an electrolyzer to produce hydrogen, which is then stored. This process of producing green hydrogen from renewable energy (solar energy) produces zero carbon emissions, achieving clean energy utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a structural block diagram of an integrated comprehensive energy system that coordinates hydrogen, light, electricity and heat, provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0044] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "inside", "outside" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention; the terms "first", "second", and "third" are only used for descriptive purposes and should not be understood as indicating or implying relative importance; in addition, unless otherwise expressly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or a communication between the internal parts of the two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Combine Figure 1 As shown, this embodiment provides an integrated comprehensive energy system that coordinates hydrogen, light, electricity and heat, including a power controller, a photovoltaic array, an electrolyzer, a fuel cell, a compressor, a heat exchanger, a hydrogen condenser, an exhaust gas heat recovery device, an energy storage system, a power grid and a load system; wherein the energy storage system includes energy storage batteries, hydrogen storage bottles and heat storage tanks; the load system includes electricity users, heat users and hydrogen refueling machines.

[0046] Specifically, the power controller is electrically connected to the photovoltaic array, energy storage battery, power grid, electricity users, fuel cells and hydrogen storage bottles, and is used to monitor the power generation of the photovoltaic array, the load demand of electricity users, the capacity status of the energy storage battery and the capacity status of the hydrogen storage bottle, so as to regulate the operation mode of the integrated comprehensive energy system in real time and achieve reasonable energy supply.

[0047] The power output end of the photovoltaic array is divided into three paths, which are respectively connected to the power input end of the electricity user, energy storage battery and electrolyzer.

[0048] The electric energy input end of the electrolyzer is connected to the electric energy output end of the photovoltaic array; the cooling water output end of the electrolyzer is connected to the thermal energy input end of the heat exchanger, and the thermal energy output end of the heat exchanger is connected to the thermal energy input end of the heat storage tank; the hydrogen output end of the electrolyzer is connected to the hydrogen input end of the hydrogen condenser; the condensed water output end of the hydrogen condenser is connected to the thermal energy input end of the heat storage tank; the hydrogen output end of the hydrogen condenser is connected to the hydrogen input end of the compressor, and the hydrogen output end of the compressor is connected to the hydrogen storage bottle, and the produced hydrogen is stored in the hydrogen storage bottle.

[0049] The hydrogen input end of the fuel cell is connected to the hydrogen output end of the hydrogen storage bottle; the power output end of the fuel cell is connected to the power input end of the electricity user; the high-temperature exhaust gas output end of the fuel cell is connected to the high-temperature exhaust gas input end of the exhaust gas heat recovery device, and the heat energy output end of the exhaust gas heat recovery device is connected to the heat energy input end of the heat storage tank; the cooling water output end of the fuel cell is connected to the heat energy input end of the heat exchanger, and the heat energy output end of the heat exchanger is connected to the heat energy input end of the heat storage tank.

[0050] The power input end of the electricity user is connected to the power output end of the photovoltaic array, energy storage battery, fuel cell and power grid respectively.

[0051] The power input end of the energy storage battery is connected to the power output end of the photovoltaic array; the power output end of the energy storage battery is connected to the power input end of the electricity user.

[0052] The hydrogen input end of the hydrogen storage bottle is connected to the hydrogen output end of the compressor; the hydrogen output end of the hydrogen storage bottle is divided into two paths, which are respectively connected to the hydrogen input ends of the fuel cell and the hydrogen refueling machine.

[0053] The heat energy input end of the heat storage tank is divided into four routes, which are respectively connected to the exhaust gas heat recovery device, the hydrogen condenser and the heat energy output ends of the two heat exchangers; the heat energy output end of the heat storage tank is connected to the heat energy input end of the heat user.

[0054] Preferably, the electrolytic cell of this embodiment is an alkaline electrolytic cell, and the chemical reaction in the electrolytic cell is: 2H2O→2H2+O2. The fuel cell is a proton exchange membrane fuel cell (low temperature or high temperature), and the chemical reaction in the fuel cell is: O2+2H2→2H2O.

[0055] This embodiment also provides an operation method of the above-mentioned integrated comprehensive energy system, which mainly includes an energy management process, a hydrogen processing process and a thermal energy processing process.

[0056] 1. Energy management process:

[0057] When the power load demand fluctuates, the power controller changes the system's operating mode in real time based on the set system operation priority principle, using the photovoltaic array power generation, energy storage battery capacity status, and hydrogen storage tank capacity status as decision variables to coordinate energy balance.

[0058] The system operation priority principles set in the power controller are as follows:

[0059] When there is excess photovoltaic power, the remaining photovoltaic power is distributed according to a predetermined ratio, and is supplied to energy storage batteries and electrolyzers at the same time for charging the energy storage batteries and producing hydrogen in the electrolyzers; if the energy storage batteries and hydrogen storage bottles are full, the surplus power is connected to the grid; when there is insufficient photovoltaic power, the energy storage batteries and fuel cells are jointly supplied with power according to a predetermined ratio to compensate for the remaining electrical load; if the capacity of both the energy storage batteries and hydrogen storage bottles is insufficient, electricity is purchased from the grid.

[0060] The factors determining the ratio include:

[0061] 1. The capacity configuration of electrolyzer, energy storage battery and fuel cell;

[0062] 2. Light conditions in the area;

[0063] 3. The electricity, heat and hydrogen load in the area.

[0064] Depending on the scenario, the system of this embodiment can run in the following 9 operating modes:

[0065] (1) When the photovoltaic array power generation power is higher than the load demand, and the energy storage battery and hydrogen storage tank are not full, the photovoltaic array supplies power to the load, and the power controller distributes the remaining photovoltaic power according to a predetermined ratio, with part of it used to charge the energy storage battery and the other part used to produce hydrogen in the electrolyzer. The produced hydrogen is stored to supply the fuel cell for power generation;

[0066] (2) When the power generated by the photovoltaic array is higher than the electrical load demand, and the energy storage battery capacity is full but the hydrogen storage tank capacity is not full, the photovoltaic array supplies power to the electrical load, and the remaining power is transmitted to the electrolyzer;

[0067] (3) When the power generated by the photovoltaic array is higher than the electrical load demand, and the hydrogen storage tank capacity is full but the energy storage battery capacity is not full, the photovoltaic array supplies power to the electrical load, and the remaining power is transmitted to the energy storage battery;

[0068] (4) When the power generated by the photovoltaic array is higher than the electrical load demand, and the energy storage battery and hydrogen storage tank are full, the photovoltaic array supplies power to the electrical load, and the remaining power is transmitted to the grid;

[0069] (5) When the power generated by the photovoltaic array is equal to the electrical load demand, the photovoltaic array output will supply power to the electrical load;

[0070] (6) When the power generation of the photovoltaic array is lower than the electric load demand, and the fuel cell and hydrogen storage tank have surplus capacity, the photovoltaic array will supply power to part of the electric load, and the energy storage battery and fuel cell will jointly supply power to the remaining electric load in a predetermined ratio. The energy storage battery will compensate for part of the remaining electric load, and the fuel cell will compensate for the other part of the remaining electric load.

[0071] (7) When the power generation of the photovoltaic array is lower than the electrical load demand, and the capacity of the hydrogen storage bottle is insufficient and the energy storage battery has surplus capacity, the photovoltaic array and the energy storage battery will jointly supply power to the electrical load;

[0072] (8) When the power generated by the photovoltaic array is lower than the electrical load demand, and the energy storage battery capacity is insufficient and the hydrogen storage tank capacity is surplus, the photovoltaic array and fuel cell will jointly supply power to the electrical load;

[0073] (9) When the power generation capacity of the photovoltaic array is lower than the electrical load demand, and the capacity of the energy storage battery and hydrogen storage bottle is insufficient, the photovoltaic array will supply power to part of the electrical load, and the remaining electrical load will be supplied by the power grid.

[0074] 2. Hydrogen treatment process:

[0075] The hydrogen in the hydrogen storage tank has two uses: one is to provide fuel for fuel cell power generation; the other is to be used in hydrogen refueling machines to refill hydrogen for fuel cell vehicles.

[0076] 3. Thermal treatment process:

[0077] For fuel cells, the high-temperature exhaust gas generated by the combustion of air and hydrogen in the fuel cell stack, as well as the high-temperature water mixed in it as a combustion product, are passed through the exhaust gas heat recovery device to transfer the heat to the heat medium. The heat generated by the fuel cell stack is carried away by the cooling water, which transfers the heat to the heat medium in the heat exchanger and is recycled. The heat medium then transfers the heat to the water in the heat storage tank to achieve thermal energy storage.

[0078] For the electrolyzer, the high-temperature hydrogen produced by the electrolysis of water is first passed into the hydrogen cooler for cooling, and the heat in the high-temperature hydrogen is taken away by the heat medium; the heat generated by the battery stack after reaching the rated temperature is taken away by the cooling water, and the cooling water transfers the heat to the heat medium in the heat exchanger and is recycled again; then the heat medium transfers the heat to the water in the heat storage tank to realize the storage of thermal energy.

[0079] In summary, the integrated hydrogen-photovoltaic-electrical-thermal energy system provided in this embodiment has the following advantages:

[0080] (1) In this system, a power controller is used to manage the energy of the system. When the electric load demand fluctuates, it will change the system operation mode in real time according to the set system operation priority principle, with the photovoltaic array power generation, energy storage battery capacity state (SOC) and hydrogen storage bottle capacity state (SOH) as decision variables, and perform coordinated control of energy balance. Among them, since the energy storage battery has limited capacity but fast response speed, the fuel cell is only limited by the hydrogen storage capacity but has a slow response speed. Moreover, although the energy conversion efficiency of the electrolyzer to produce hydrogen for fuel cell power generation is relatively low, this method has the unique advantages of long cycle and large scale. The combination of the two can well cope with the changing load demand. Therefore, the priority principle sets the ratio of excess photovoltaic power to the energy storage battery and electrolyzer, and the ratio of energy storage battery and fuel cell power generation to compensate for the remaining electric load when photovoltaic power is insufficient. This reasonable distribution of power can reduce the problem of abandoned light, maximize energy utilization, improve the overall efficiency of the system, and enable the system to better cope with changes in electric load demand and operate stably in the long term.

[0081] (2) This system integrates photovoltaic power generation, fuel cell power generation, water electrolysis hydrogen production, energy storage, hydrogen storage, and heat storage. The photovoltaic array is supplemented by fuel cells, energy storage batteries, and the power grid to meet the changing load demands of electricity users, and the energy storage batteries and electrolyzers absorb excess photovoltaic power. Since the dynamic response of fuel cells is slow, they cannot provide power for several hours in the case of sudden load changes, while the dynamic response of energy storage batteries is fast, which can well compensate for the power shortage caused by load changes. First, the system involves solar energy, hydrogen energy, electricity, and thermal energy, realizing the complementarity and supply and demand coordination of multiple energy sources, effectively improving the comprehensive energy efficiency of the system, and being able to meet the multiple load demands of electricity, hydrogen, and heat at the same time; then, the electricity generated by photovoltaics is used to electrolyze water through electrolyzers to produce hydrogen, which is then stored. In this process, the use of renewable energy (solar energy) to produce green hydrogen has zero carbon emissions and realizes the use of clean energy.

[0082] (3) This system can recycle and reuse the waste heat generated by important components (such as fuel cells and electrolyzers) to meet the heat load requirements. Specifically, the heat in the high-temperature exhaust gas mixed with water generated by the combustion of the fuel cell, the heat generated when the fuel cell is working, the heat in the high-temperature hydrogen produced by the electrolyzer through the electrolysis of water, and the heat generated by the electrolyzer after it reaches the rated temperature are transferred to the heat medium (water) and stored in the heat storage tank. This process not only recycles the waste heat of the electrolyzer and fuel cell to meet the user's heat load requirements, but also achieves the effect of energy conservation and emission reduction. It not only improves the overall energy efficiency of the system and reduces energy waste, but also effectively prevents the temperature of the electrolyzer and fuel cell from being too high, ensuring the production efficiency and quality of the components.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An integrated energy system of synergistic hydrogen-light-electricity-heat, characterized in that: It includes a power controller, a photovoltaic array, an electrolyzer, a fuel cell, a compressor, a heat exchanger, a hydrogen condenser, a tail gas heat recovery device, an energy storage system, a power grid and a load system; wherein the energy storage system includes energy storage batteries, hydrogen storage bottles and heat storage tanks; the load system includes electricity users, heat users and hydrogen refueling machines; The power controller is electrically connected to the photovoltaic array, the energy storage battery, the power grid, the electricity user, the fuel cell and the hydrogen storage bottle, and is used to monitor the power generation of the photovoltaic array, the load demand of the electricity user, the capacity state of the energy storage battery and the capacity state of the hydrogen storage bottle, so as to regulate the operation mode of the integrated comprehensive energy system in real time and realize reasonable energy supply; The power output end of the photovoltaic array is divided into three paths, which are respectively connected to the power user, the energy storage battery and the power input end of the electrolyzer; The electric energy input end of the electrolyzer is connected to the electric energy output end of the photovoltaic array; the cooling water output end of the electrolyzer is connected to the thermal energy input end of the heat exchanger, and the thermal energy output end of the heat exchanger is connected to the thermal energy input end of the heat storage tank; the hydrogen output end of the electrolyzer is connected to the hydrogen input end of the hydrogen condenser; the condensed water output end of the hydrogen condenser is connected to the thermal energy input end of the heat storage tank; the hydrogen output end of the hydrogen condenser is connected to the hydrogen input end of the compressor, and the hydrogen output end of the compressor is connected to the hydrogen storage bottle, and the produced hydrogen is stored in the hydrogen storage bottle; The hydrogen input end of the fuel cell is connected to the hydrogen output end of the hydrogen storage bottle; the electric energy output end of the fuel cell is connected to the electric energy input end of the electricity user; the high-temperature tail gas output end of the fuel cell is connected to the high-temperature tail gas input end of the tail gas heat recovery device, and the heat energy output end of the tail gas heat recovery device is connected to the heat energy input end of the heat storage tank; the cooling water output end of the fuel cell is connected to the heat energy input end of the heat exchanger, and the heat energy output end of the heat exchanger is connected to the heat energy input end of the heat storage tank; The power input end of the power user is respectively connected to the power output end of the photovoltaic array, the energy storage battery, the fuel cell, and the power grid; The power input end of the energy storage battery is connected to the power output end of the photovoltaic array; the power output end of the energy storage battery is connected to the power input end of the electricity user; The hydrogen input end of the hydrogen storage bottle is connected to the hydrogen output end of the compressor; the hydrogen output end of the hydrogen storage bottle is divided into two paths, which are respectively connected to the hydrogen input end of the fuel cell and the hydrogen filling machine; The heat energy input end of the heat storage tank is divided into four paths, which are respectively connected to the tail gas heat recovery device, the hydrogen condenser and the heat energy output ends of the two heat exchangers; the heat energy output end of the heat storage tank is connected to the heat energy input end of the heat user.

2. A method for operating the integrated comprehensive energy system according to claim 1, characterized in that: Energy management processes include: When the electric load demand fluctuates, the power controller changes the system operation mode in real time according to the set system operation priority principle, taking the photovoltaic array power generation, the energy storage battery capacity state and the hydrogen storage bottle capacity state as decision variables, and performs coordinated control of energy balance; The system operation priority principles set in the power controller are as follows: When there is excess photovoltaic power, the remaining photovoltaic power is distributed according to a predetermined ratio, and is supplied to energy storage batteries and electrolyzers at the same time for charging the energy storage batteries and producing hydrogen in the electrolyzers. If the energy storage batteries and hydrogen storage bottles are full, the surplus electricity is connected to the grid. When photovoltaic power is insufficient, energy storage batteries and fuel cells jointly supply power according to a predetermined ratio to compensate for the remaining electrical load. If the capacity of both the energy storage batteries and hydrogen storage bottles is insufficient, electricity is purchased from the grid.

3. The method for operating the integrated comprehensive energy system according to claim 2, characterized in that: The factors determining the ratio include: (1) The capacity configuration of electrolyzers, energy storage batteries, and fuel cells; (2) Light conditions in the area; (3) The load of electricity, heat and hydrogen in the area.

4. The method for operating the integrated comprehensive energy system according to claim 2, characterized in that: The following operating modes are included: (1) When the power generated by the photovoltaic array is higher than the electric load demand, and the capacity of the energy storage battery and the hydrogen storage bottle is not full, the photovoltaic array supplies power to the electric load, and the power controller distributes the remaining photovoltaic power according to a predetermined ratio, part of which is used to charge the energy storage battery and the other part is used to produce hydrogen in the electrolyzer, and the produced hydrogen is stored to supply the fuel cell for power generation; (2) When the power generated by the photovoltaic array is higher than the electric load demand, and the energy storage battery capacity is full but the hydrogen storage bottle capacity is not full, the photovoltaic array supplies power to the electric load, and the remaining power is transmitted to the electrolyzer; (3) When the power generated by the photovoltaic array is higher than the electric load demand, and the capacity of the hydrogen storage bottle is full but the capacity of the energy storage battery is not full, the photovoltaic array supplies power to the electric load, and the remaining power is transmitted to the energy storage battery; (4) When the power generated by the photovoltaic array is higher than the power load demand, and the energy storage battery and hydrogen storage bottle are full, the photovoltaic array supplies power to the power load, and the remaining power is transmitted to the power grid; (5) When the power generated by the photovoltaic array is equal to the power load demand, the photovoltaic array outputs power to supply the power load; (6) When the power generation of the photovoltaic array is lower than the electric load demand, and both the fuel cell and the hydrogen storage bottle have surplus capacity, the photovoltaic array supplies power to part of the electric load, and the energy storage battery and the fuel cell jointly supply power to the remaining electric load in a predetermined ratio, the energy storage battery compensates for part of the remaining electric load, and the fuel cell compensates for another part of the remaining electric load; (7) When the power generation of the photovoltaic array is lower than the demand of the electric load, and the capacity of the hydrogen storage bottle is insufficient and the capacity of the energy storage battery is surplus, the photovoltaic array and the energy storage battery jointly supply power to the electric load; (8) When the power generation of the photovoltaic array is lower than the demand of the electric load, and the capacity of the energy storage battery is insufficient and the capacity of the hydrogen storage bottle is surplus, the photovoltaic array and the fuel cell are combined to supply power to the electric load; (9) When the power generation power of the photovoltaic array is lower than the power load demand and the capacity of the energy storage battery and the hydrogen storage bottle are insufficient, the photovoltaic array will supply power to part of the power load, and the remaining power load will be supplied by the power grid.

5. The method for operating the integrated comprehensive energy system according to claim 2, characterized in that: Also includes hydrogen treatment process: The hydrogen in the hydrogen storage tank has two uses: one is to provide fuel for fuel cell power generation; the other is to be used in a hydrogen refueling machine to refill hydrogen for fuel cell vehicles.

6. The method for operating the integrated comprehensive energy system according to claim 2, characterized in that: Also includes thermal energy treatment processes: For fuel cells, the high-temperature exhaust gas generated by the combustion of air and hydrogen in the stack and the high-temperature water mixed in the combustion product are introduced into the exhaust gas heat recovery device to transfer the heat to the heat medium; the heat generated by the operation of the stack is taken away by the cooling water, which transfers the heat to the heat medium in the heat exchanger and is recycled again; then the heat medium transfers the heat to the water in the heat storage tank to achieve the storage of thermal energy; For the electrolyzer, the high-temperature hydrogen produced by the electrolysis of water is first passed into the hydrogen cooler for cooling, and the heat in the high-temperature hydrogen is taken away by the heat medium; the heat generated by the battery stack after reaching the rated temperature is taken away by the cooling water, and the cooling water transfers the heat to the heat medium in the heat exchanger and is recycled again; then the heat medium transfers the heat to the water in the heat storage tank to achieve the storage of thermal energy.

7. The method for operating the integrated comprehensive energy system according to claim 2, characterized in that: The electrolytic cell is an alkaline electrolytic cell, and the chemical reaction in the electrolytic cell is: 2H2O→2H2+O2.

8. The method for operating the integrated comprehensive energy system according to claim 2, characterized in that: The fuel cell is a proton exchange membrane fuel cell, and the chemical reaction in the fuel cell is: O2+2H2→2H2O.

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