Thermoelectric hydrogen coupling system applied to charging station and control method thereof

Abstract

The invention relates to a thermoelectric hydrogen coupling system applied to a charging station and a control method thereof.The system comprises a power supply subsystem, a thermal interaction subsystem, a hydrogen energy storage subsystem and an energy charging subsystem, and the power supply subsystem is used for generating electric energy to meet the load requirement of the charging station; the thermal interaction subsystem is used for absorbing heat energy and completing heat exchange so as to provide a thermal reactant to the hydrogen energy storage subsystem; the hydrogen energy storage subsystem is used for realizing conversion between electric energy and hydrogen energy and storing generated hydrogen; the energy charging subsystem is used for providing electric energy for the electric automobile and providing hydrogen energy for the hydrogen energy automobile. According to the control method, the operation mode of the charging station and the working mode of the solid oxide equipment are adjusted according to different supply and demand conditions by detecting the photovoltaic generating capacity, the load demand quantity and the hydrogen storage quantity in the hydrogen storage tank in real time. Compared with the prior art, the requirements for electric energy and hydrogen in the charging station are met through electricity-hydrogen coupling, and meanwhile the energy utilization rate of the charging station is increased through heat energy.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen refueling-charging integration, and in particular to a thermoelectric hydrogen coupling system applied to a charging station and a control method thereof. Background Art

[0002] As the demand for energy structure transformation is raised, clean energy is an important fulcrum to promote the success of this transformation. At present, the market demand for electric vehicles and hydrogen energy vehicles is growing rapidly. Compared with traditional fuel vehicles, electric vehicles can greatly reduce carbon emissions and save energy costs. Hydrogen energy vehicles further use hydrogen energy as a vehicle power source. Compared with traditional energy, hydrogen energy has the advantages of zero pollution, abundant resources, and high efficiency. Hydrogen energy storage has the characteristics of high energy density and strong long-term energy storage capacity.

[0003] But at the same time, the existing backward charging facilities and service levels cannot meet the charging needs of new energy vehicles, so new charging stations and hydrogen refueling stations need to be quickly implemented to adapt to the development trend of new energy vehicles. Although the current charging station system that integrates photovoltaics, electrolysis cells and hydrogen refueling devices can effectively solve the problems of hydrogen production, filling and charging, the charging station system cannot achieve two-way conversion of electrical energy and hydrogen energy, resulting in energy waste in the charging station, and the high temperature of the photovoltaic panels will also reduce the power generation efficiency, resulting in low energy utilization of the charging station. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a thermoelectric hydrogen coupling system and a control method for a charging station, so as to meet the demand for electricity and hydrogen in the charging station through electric hydrogen coupling, and at the same time utilize thermal energy to improve the energy utilization rate of the charging station.

[0005] The object of the present invention can be achieved by the following technical solutions: A thermoelectric hydrogen coupling system applied to a charging station comprises a power supply subsystem, a heat interaction subsystem, a hydrogen energy storage subsystem and a charging subsystem, wherein the power supply subsystem is used to generate electric energy to meet the load demand of the charging station;

[0006] The heat interaction subsystem is used to absorb heat energy and complete heat exchange to provide heat reactants to the hydrogen energy storage subsystem;

[0007] The hydrogen energy storage subsystem is used to realize the conversion of electrical energy and hydrogen energy and store the generated hydrogen;

[0008] The charging subsystem is used to provide electrical energy to electric vehicles and hydrogen energy to hydrogen energy vehicles.

[0009] Furthermore, the power supply subsystem includes a grid power supply unit and a photovoltaic / thermal (PV / T) power generation device that cooperate with each other to supply power.

[0010] Furthermore, the photovoltaic thermal power generation equipment is connected to the power supply bus through a first DC / DC converter, and the grid power supply unit is connected to the power supply bus through an AC / DC converter.

[0011] Furthermore, the thermal interaction subsystem includes a heat transfer medium and a heat exchange device, the heat exchange device includes a gasifier and a steam superheater, the heat transfer medium includes water and hydrogen, which is used to absorb heat from the photovoltaic thermal power generation equipment, the water is stored in a water tank, and the hydrogen comes from the hydrogen energy storage subsystem.

[0012] Furthermore, the hydrogen energy storage subsystem includes a solid oxide device, a compressor and a hydrogen storage tank. The solid oxide device is used to realize the conversion of electrical energy and hydrogen energy. The hydrogen generated by the solid oxide device is compressed by the compressor and stored in the hydrogen storage tank.

[0013] Furthermore, the solid oxide device is connected to the power supply bus through a second DC / DC converter.

[0014] Furthermore, the charging subsystem includes a charging pile and a hydrogen refueling pile, the charging pile is connected to the power supply bus through a third DC / DC converter, and the hydrogen refueling pile is connected to the hydrogen storage tank.

[0015] A control method for a thermoelectric hydrogen coupling system applied to a charging station comprises the following steps:

[0016] S1, real-time detection of current photovoltaic power generation, load demand and hydrogen storage in the hydrogen storage tank;

[0017] S2. According to the current photovoltaic power generation, load demand and hydrogen storage in the hydrogen storage tank, determine the current supply and demand situation and adjust the operating status of the charging station accordingly:

[0018] When there is surplus photovoltaic power generation and sufficient hydrogen reserves, the surplus photovoltaic power generation will be connected to the grid;

[0019] When there is excess photovoltaic power generation and insufficient hydrogen reserves, the surplus photovoltaic power generation is used for electrolysis to produce hydrogen;

[0020] When photovoltaic power generation is insufficient and hydrogen reserves are sufficient, fuel cells are used to supply power to meet the load requirements of the charging station;

[0021] When photovoltaic power generation is insufficient and hydrogen storage is insufficient, power is supplied by the grid to meet the load demand of the charging station.

[0022] Furthermore, in step S2, when the photovoltaic power generation is in surplus and the hydrogen reserves are insufficient, the specific process of using the surplus photovoltaic power generation for electrolytic hydrogen production is as follows:

[0023] Open the water tank valve, and after absorbing the heat from the photovoltaic panels, the water completes the heat exchange in the heat exchange equipment and finally passes into the solid oxide equipment. At this time, the solid oxide equipment works in the electrolysis cell mode, and the excess electricity is used for electrolysis to produce hydrogen. When the hydrogen reserves in the hydrogen storage tank are sufficient, close the water tank valve and the charging station sells electricity to the power grid.

[0024] Furthermore, in step S2, when the photovoltaic power generation is insufficient and the hydrogen storage is sufficient, the specific process of using the fuel cell to supply power to meet the load demand of the charging station is as follows:

[0025] Open the valve of the hydrogen storage tank. After absorbing the heat from the photovoltaic panel, the hydrogen completes the heat exchange in the heat exchange equipment and finally passes into the solid oxide device. At this time, the solid oxide device works in the fuel cell mode to make up for the power shortage in the charging station. When the hydrogen reserves in the hydrogen storage tank are insufficient, close the valve of the hydrogen storage tank and the charging station purchases electricity from the power grid to meet the load demand.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The present invention is provided with a power supply subsystem, a heat interaction subsystem, a hydrogen energy storage subsystem and a charging subsystem, the power supply subsystem is used to generate electric energy to meet the load demand of the charging station, the heat interaction subsystem is used to absorb heat energy and complete heat exchange to provide thermal reactants to the hydrogen energy storage subsystem, the hydrogen energy storage subsystem is used to realize the conversion of electric energy and hydrogen energy, and the generated hydrogen is stored, and the charging subsystem is used to provide electric energy to electric vehicles and hydrogen energy to hydrogen energy vehicles. In this way, the demand for electric energy and hydrogen in the charging station is met through the electric-hydrogen coupling form, and the energy utilization rate of the charging station is improved by using heat energy.

[0028] The present invention adopts solid oxide equipment in the hydrogen energy storage subsystem and PV / T equipment (i.e., photovoltaic thermal power generation equipment) in the power supply subsystem, which can ensure that the charging station can achieve efficient hydrogen production and mutual conversion of hydrogen energy and electrical energy at high temperature. The solid oxide equipment can improve the efficiency of hydrogen production by electrolysis of water, and can also adjust the storage of electrical energy and hydrogen energy in the station to cope with the problems of insufficient photovoltaic power generation and insufficient hydrogen refueling of hydrogen fuel vehicles in extreme cases. In addition, a thermal interaction system is introduced in the charging station. After absorbing the heat energy collected by the PV / T equipment, water or hydrogen completes heat exchange in the thermal interaction system, and finally rises to a working temperature that meets the solid oxide equipment, thereby consuming the heat energy generated on the photovoltaic panel during photovoltaic power generation, reducing the temperature of the photovoltaic panel, and greatly improving the photoelectric conversion efficiency of the photovoltaic panel.

[0029] The present invention adjusts the operation mode of the charging station by real-time detection of photovoltaic power generation, load demand and hydrogen storage in the hydrogen storage tank, that is, the operation mode of the charging station and the working mode of the solid oxide equipment are adjusted according to different supply and demand conditions. When the photovoltaic power generation is greater than the load demand, the excess photovoltaic power generation is used for solid oxide electrolysis hydrogen production (SOEC), and when the storage of the hydrogen storage tank reaches the upper capacity limit, the remaining photovoltaic power generation is used for access to the Internet; when the photovoltaic power generation is less than the load demand, the solid oxide fuel cell (SOFC) generates electricity to make up for the shortfall in electricity, and when the storage of the hydrogen storage tank is lower than the lower capacity limit, the shortfall in electricity is made up by the power grid. It can not only improve the energy utilization rate of the charging station, but also improve the conversion efficiency between energies. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the system structure of the present invention;

[0031] Figure 2 It is a schematic diagram of the method flow of the present invention;

[0032] Figure 3 It is a schematic diagram of the working mode of the electrolytic cell (SOEC) of the solid oxide device in the present invention;

[0033] Figure 4 It is a schematic diagram of the working mode of the battery (SOFC) of the solid oxide device in the present invention;

[0034] Figure 5 This is a comparison diagram of the efficiency of the charging station before and after the installation of the PV / T equipment in the embodiment;

[0035] Explanation of the marks in the figure: 101, grid power supply unit, 102, photovoltaic thermal power generation equipment, 103, first DC / DC converter, 104, AC / DC converter, 201, heat exchange equipment, 202, water tank, 301, solid oxide equipment, 302, hydrogen storage tank, 303, second DC / DC converter, 401, charging pile, 402, hydrogen refueling pile, 403, third DC / DC converter. DETAILED DESCRIPTION

[0036] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Example

[0038] A thermoelectric hydrogen coupling system applied to a charging station comprises a power supply subsystem, a heat interaction subsystem, a hydrogen energy storage subsystem and a charging subsystem, wherein the power supply subsystem is used to generate electric energy to meet the load demand of the charging station;

[0039] The heat interaction subsystem is used to absorb heat energy and complete heat exchange to provide heat reactants to the hydrogen energy storage subsystem;

[0040] The hydrogen energy storage subsystem is used to realize the conversion of electrical energy and hydrogen energy and store the generated hydrogen;

[0041] The charging subsystem is used to provide electrical energy to electric vehicles and hydrogen energy to hydrogen energy vehicles.

[0042] Specifically, Figure 1 As shown, the power supply subsystem includes a grid power supply unit 101 and a photovoltaic thermal power generation device 102 that cooperate with each other to provide power. The photovoltaic thermal power generation device 102 is connected to the power supply bus through a first DC / DC converter 103, and the grid power supply unit 101 is connected to the power supply bus through an AC / DC converter 104.

[0043] The thermal interaction subsystem includes a heat transfer medium and a heat exchange device 201. The heat exchange device 201 includes a vaporizer and a steam superheater. The heat transfer medium includes water and hydrogen, which is used to absorb the heat of the photovoltaic thermal power generation equipment 102. The water is stored in the water tank 202, and the hydrogen comes from the hydrogen energy storage subsystem.

[0044] The hydrogen energy storage subsystem includes a solid oxide device 301, a compressor and a hydrogen storage tank 302. The solid oxide device 301 is used to realize the conversion of electrical energy and hydrogen energy. The hydrogen generated by the solid oxide device 301 is compressed by the compressor and stored in the hydrogen storage tank 302. The solid oxide device 301 is connected to the power supply bus through a second DC / DC converter 303.

[0045] The charging subsystem includes a charging pile 401 and a hydrogen refueling pile 402 . The charging pile 401 is connected to the power supply bus through a third DC / DC converter 403 , and the hydrogen refueling pile 402 is connected to the hydrogen storage tank 302 .

[0046] Thus, by using the solid oxide device 301 and the PV / T device (i.e., the photovoltaic thermal power generation device 102), the charging station is guaranteed to achieve efficient hydrogen production and mutual conversion of hydrogen energy and electric energy at high temperature, and can consume the heat energy generated on the photovoltaic panels during photovoltaic power generation, reduce the temperature of the photovoltaic panels, and improve the photoelectric conversion efficiency of the photovoltaic panels. A thermal interaction system is introduced in the charging station, and water or hydrogen completes heat exchange in the thermal interaction system after absorbing the heat energy collected by the PV / T device, and finally rises to a temperature that meets the working temperature of the solid oxide device 301.

[0047] The control method of the above system is as follows Figure 2 As shown, the operation mode of the charging station is adjusted according to the real-time detected photovoltaic power generation, load demand and hydrogen storage in the hydrogen storage tank: when the photovoltaic power generation is surplus and the hydrogen storage is sufficient, the surplus photovoltaic power generation is connected to the grid;

[0048] When there is surplus photovoltaic power generation and insufficient hydrogen reserves, the surplus photovoltaic power generation is used to produce hydrogen by electrolysis;

[0049] When photovoltaic power generation is insufficient and hydrogen reserves are sufficient, the fuel cell supplies power to meet the charging station load demand;

[0050] When photovoltaic power generation is insufficient and hydrogen storage is insufficient, the grid supplies power to meet the load demand of the charging station.

[0051] Specifically, the photovoltaic power generation, load demand and hydrogen storage in the hydrogen storage tank are detected in real time. When the photovoltaic power generation is greater than the load demand, the excess photovoltaic power generation is used for solid oxide electrolysis hydrogen production (SOEC). When the storage capacity of the hydrogen storage tank reaches the upper limit of capacity, the remaining photovoltaic power generation is used for grid connection. When the photovoltaic power generation is less than the load demand, the solid oxide fuel cell (SOFC) power generation makes up for the shortfall. When the storage capacity of the hydrogen storage tank is lower than the lower limit of capacity, the power grid makes up for the shortfall.

[0052] Figure 3 This is a diagram of the SOEC working mode. After the water in the water tank absorbs the heat from the photovoltaic thermal power generation equipment, it is vaporized into water vapor in the vaporizer, and then heated to a specified temperature in the steam superheater and passed into the anode of the solid oxide device. In the solid oxide device, it is electrolyzed into hydrogen and oxygen. The oxygen is discharged from the outlet after heat exchange in the steam superheater, and the hydrogen is stored in the hydrogen storage tank after heat exchange in the steam superheater.

[0053] Figure 4 This is a diagram of the SOFC working mode. After absorbing the heat from the photovoltaic thermal power generation equipment, the hydrogen in the hydrogen storage tank is heated to a specified temperature in the steam superheater and then passed into the anode of the solid oxide device. At the same time, the air passes through the steam superheater and is heated to a specified temperature before passing into the cathode of the solid oxide device. Power generation is achieved in the solid oxide device, and water vapor is generated at the anode. The water vapor is liquefied through heat exchange in the steam superheater and then passed into the water tank.

[0054] Since the solid oxide equipment is more efficient in the above two modes in a high temperature environment, photovoltaic thermal power generation equipment and heat exchange equipment are installed to ensure that the solid oxide equipment works at a suitable temperature. The installation of photovoltaic thermal power generation equipment can not only provide heat for the solid oxide equipment to reduce the power consumption of the entire system and improve the efficiency of the charging station, but also reduce the temperature of the photovoltaic panels in the photovoltaic thermal power generation equipment to improve the photoelectric conversion efficiency of the equipment. Figure 5 It can be seen that after installing photovoltaic thermal power generation equipment, the system will consume less electricity to maintain the temperature required for the solid oxide equipment to work, and the charging station efficiency will be higher.

[0055] This scheme realizes the conversion of electricity to hydrogen through the coordination of solid oxide electrolyzer (SOEC) and solid oxide cell (SOFC). When there is insufficient electricity and excess hydrogen, the solid oxide device works in battery mode to convert hydrogen into electricity; when there is sufficient electricity and insufficient hydrogen, the solid oxide device works in electrolyzer mode to convert electricity into hydrogen. Compared with traditional alkaline water electrolysis (ALE) and proton exchange membrane water electrolysis (SPE) and fuel cells, this working mode has a higher conversion efficiency.

[0056] In order to verify that this solution is more economical and environmentally friendly than the existing technology, this embodiment sets up the following four system solutions for comparative analysis:

[0057] (1) Option 1: Use solid oxide equipment and photovoltaic thermal power generation equipment.

[0058] (2) Option 2: Use alkaline water electrolysis hydrogen production equipment, energy storage batteries and photovoltaic thermal power generation equipment.

[0059] (3) Option 3: Use proton exchange membrane electrolysis hydrogen production equipment, energy storage batteries and photovoltaic thermal power generation equipment.

[0060] (4) Option 4: Using solid oxide equipment and photovoltaic power generation equipment

[0061] The initial investment cost, renewable energy utilization and charging station efficiency under several scenarios are shown in the following table.

[0062] plan Initial investment cost / yuan Renewable energy utilization rate Charging station efficiency RSOC+PV / T 608694.84 63.57％ 90.93％ AWE+Energy Storage Battery+PV / T 624257.49 61.01％ 84.78％ PEME+Energy Storage Battery+PV / T 735312.98 59.87％ 87.31％ RSOC+PV 584943.81 61.95％ 87.76％

[0063] It can be seen that compared with the traditional typical charging station system, the system proposed in this scheme has a lower initial investment cost and higher renewable energy utilization rate and charging station efficiency, so it has better economy and environmental protection.

Claims

1. A thermoelectric hydrogen coupling system applied to a charging station, characterized in that: It includes a power supply subsystem, a heat interaction subsystem, a hydrogen energy storage subsystem and a charging subsystem, wherein the power supply subsystem is used to generate electrical energy to meet the load demand of the charging station; The heat interaction subsystem is used to absorb heat energy and complete heat exchange to provide heat reactants to the hydrogen energy storage subsystem; The hydrogen energy storage subsystem is used to realize the conversion of electrical energy and hydrogen energy and store the generated hydrogen; The charging subsystem is used to provide electric energy to electric vehicles and hydrogen energy to hydrogen energy vehicles.

2. The thermoelectric hydrogen coupling system for a charging station according to claim 1, characterized in that: The power supply subsystem comprises a power grid power supply unit (101) and a photovoltaic thermal power generation device (102) which cooperate with each other to supply power.

3. The thermoelectric hydrogen coupling system for a charging station according to claim 2, characterized in that: The photovoltaic thermal power generation device (102) is connected to the power supply bus through a first DC / DC converter (103), and the grid power supply unit (101) is connected to the power supply bus through an AC / DC converter (104).

4. The thermoelectric hydrogen coupling system for a charging station according to claim 3, characterized in that: The thermal interaction subsystem includes a heat transfer medium and a heat exchange device (201), wherein the heat exchange device (201) includes a vaporizer and a steam superheater, and the heat transfer medium includes water and hydrogen for absorbing heat from the photovoltaic thermal power generation device (102). The water is stored in a water tank (202), and the hydrogen comes from a hydrogen energy storage subsystem.

5. The thermoelectric hydrogen coupling system for a charging station according to claim 4, characterized in that: The hydrogen energy storage subsystem comprises a solid oxide device (301), a compressor and a hydrogen storage tank (302). The solid oxide device (301) is used to realize the conversion of electric energy and hydrogen energy. The hydrogen generated by the solid oxide device (301) is compressed by the compressor and stored in the hydrogen storage tank (302).

6. The thermoelectric hydrogen coupling system for a charging station according to claim 5, characterized in that: The solid oxide device (301) is connected to the power supply bus via a second DC / DC converter (303).

7. The thermoelectric hydrogen coupling system for a charging station according to claim 5, characterized in that: The charging subsystem comprises a charging pile (401) and a hydrogen refueling pile (402), wherein the charging pile (401) is connected to a power supply bus via a third DC / DC converter (403), and the hydrogen refueling pile (402) is connected to a hydrogen storage tank (302).

8. A control method for a thermoelectric hydrogen coupling system applied to a charging station, used to control a thermoelectric hydrogen coupling system applied to a charging station as claimed in claim 5, characterized in that: The following steps are involved: S1, real-time detection of current photovoltaic power generation, load demand and hydrogen storage in the hydrogen storage tank; S2. According to the current photovoltaic power generation, load demand and hydrogen storage in the hydrogen storage tank, determine the current supply and demand situation and adjust the operating status of the charging station accordingly: When there is surplus photovoltaic power generation and sufficient hydrogen reserves, the surplus photovoltaic power generation will be connected to the grid; When there is excess photovoltaic power generation and insufficient hydrogen reserves, the surplus photovoltaic power generation is used for electrolysis to produce hydrogen; When photovoltaic power generation is insufficient and hydrogen reserves are sufficient, fuel cells are used to supply power to meet the load requirements of the charging station; When photovoltaic power generation is insufficient and hydrogen storage is insufficient, power is supplied by the grid to meet the load demand of the charging station.

9. The thermoelectric hydrogen coupling system for a charging station according to claim 8, characterized in that: In step S2, when the photovoltaic power generation is in surplus and the hydrogen reserves are insufficient, the specific process of using the surplus photovoltaic power generation for electrolytic hydrogen production is as follows: Open the water tank valve, and after absorbing the heat from the photovoltaic panels, the water completes the heat exchange in the heat exchange equipment and finally passes into the solid oxide equipment. At this time, the solid oxide equipment works in the electrolysis cell mode, and the excess electricity is used for electrolysis to produce hydrogen. When the hydrogen reserves in the hydrogen storage tank are sufficient, close the water tank valve and the charging station sells electricity to the power grid.

10. The thermoelectric hydrogen coupling system for a charging station according to claim 8, characterized in that: In step S2, when the photovoltaic power generation is insufficient and the hydrogen storage is sufficient, the specific process of using the fuel cell to supply power to meet the load demand of the charging station is as follows: Open the valve of the hydrogen storage tank. After absorbing the heat from the photovoltaic panel, the hydrogen completes the heat exchange in the heat exchange equipment and finally passes into the solid oxide device. At this time, the solid oxide device works in the fuel cell mode to make up for the power shortage in the charging station. When the hydrogen reserves in the hydrogen storage tank are insufficient, close the valve of the hydrogen storage tank and the charging station purchases electricity from the power grid to meet the load demand.

Images