Renewable energy coupling electrolyzed water system and control method thereof

Abstract

The invention discloses a renewable energy coupling electrolyzed water system and a control method thereof.The renewable energy coupling electrolyzed water system comprises a power supply assembly, an electrolyzed water assembly and a heat conduction assembly, the electrolyzed water assembly comprises a water storage tank, a water feeding pump and an electrolytic bath, and the power supply assembly is connected with the water feeding pump and the electrolytic bath; the heat conduction assembly comprises a cold storage tank, an electric heater, a hot storage tank and a first heat exchanger, the power supply assembly is connected with the electric heater, the cold storage tank conveys a heat conduction medium to the electric heater for heating, the heated heat conduction medium is conveyed to the hot storage tank for storage and / or conveyed into the first heat exchanger for heat exchange with feed water, and the heat conduction medium after heat exchange flows back to the cold storage tank; and the heat-conducting medium stored in the heat storage tank is also used for exchanging heat with the feed water. According to the system, rapid switching between an efficient hydrogen production mode and a hot standby mode can be achieved under the condition of fluctuation of wind power and photovoltaic power generation, performance degradation caused by continuous starting and stopping of an electrolytic cell due to random fluctuation of renewable energy sources is avoided, and the stability of the working performance of the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of water electrolysis, and in particular to a renewable energy coupled water electrolysis system and a control method thereof. Background Art

[0002] As global energy demand continues to increase, the use of traditional fossil energy has brought about serious environmental problems and resource shortages. Renewable energy, such as wind and solar energy, has become an important direction for future energy development due to its clean and renewable characteristics. However, these energy sources are volatile and intermittent, making it difficult to provide stable power supply, which limits their large-scale application.

[0003] In the related technologies, a technology of producing hydrogen by electrolysis of water driven by renewable energy is proposed to improve the utilization rate of renewable energy. As a green hydrogen production method, this technology has great development potential. However, it is difficult for the water electrolysis hydrogen production system to achieve efficient and stable operation when facing fluctuations in renewable energy such as wind energy and solar energy. In addition, there is also the problem of energy waste. Summary of the invention

[0004] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0005] In the related technology, there is a wind-solar-gas complementary energy storage hydrogen production system and a coordinated control method. The system adds a gas turbine on the basis of configuring a battery. The system supports the hydrogen production device to work within the optimal power range by storing electricity when the wind turbine and photovoltaic generator output high power, and supplementing the power generation of the gas turbine when the power is low. The stability, performance and service life of the electrolyzer are improved, and the cost is reduced. However, the system operating temperature of the coupled gas turbine is relatively high, and when it is applied to the proton exchange membrane electrolyzer operating at low temperature, a large amount of high-grade heat will be lost.

[0006] A coordinated control strategy for a wind-solar hybrid power generation and hydrogen production system. The power fluctuations of wind and solar power are smoothed by coupling batteries and fuel cells and formulating a control strategy for energy storage units. However, this system does not take into account the situation where batteries and fuel cells are unable to compensate for the lack of power in the water electrolysis system when the wind turbines and photovoltaic generators are under-powered for a long time.

[0007] A renewable energy coupled cascade hydrogen production system and hydrogen production method, the system uses the heat energy generated by the fuel cell to preheat the hydrogen production system, solving the problem of long cold start time of the alkaline electrolyzer. However, the system only studies the control method of the electrolyzer's rapid start, and does not consider the electrolyzer's regulation strategy under the fluctuation of wind and solar power output.

[0008] A DC off-grid photovoltaic hydrogen production system and a control method thereof, which determines the operation mode of the hydrogen production system according to the output current parameter, the maximum limit value and the output current parameter, including the maximum power mode and the non-maximum power mode, so that the DC hydrogen production power supply can achieve the maximum power output while ensuring the stability of the DC off-grid photovoltaic hydrogen production system. However, the system does not consider the coping strategy of the water electrolysis system under the fluctuation of the photovoltaic DC power supply.

[0009] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0010] To this end, an embodiment of the present invention proposes a renewable energy coupled water electrolysis system, which integrates waste heat recovery and heat storage, which can not only improve the overall efficiency of the system, but also realize the continuous and stable operation of the electrolytic hydrogen production equipment, providing a new solution for realizing the efficient utilization of renewable energy.

[0011] The renewable energy coupled water electrolysis system of the embodiment of the present invention comprises:

[0012] Power supply components;

[0013] The water electrolysis component comprises a water storage tank, a water supply pump and an electrolytic cell which are sequentially connected via pipelines, and the power supply component is connected to the water supply pump and the electrolytic cell to provide electrical energy to both;

[0014] A heat conduction component, the heat conduction component includes a cold storage tank, an electric heater, a hot storage tank and a first heat exchanger, the power supply component is connected to the electric heater to provide electric energy, the outlet of the cold storage tank is connected to the electric heater via a pipeline to transport a heat-conducting medium to the electric heater for heating, the outlet of the electric heater is connected to the hot storage tank and the cold storage tank via a pipeline, the first heat exchanger is arranged on the outlet pipeline of the water supply pump and on the pipeline from the outlet of the electric heater to the cold storage tank, so that the heated heat-conducting medium is transported to the hot storage tank for storage, and / or transported to the first heat exchanger for heat exchange with the water transported by the water supply pump, and the heat-conducting medium after heat exchange flows back to the cold storage tank, and the hot storage tank is connected to the first heat exchanger via a pipeline to utilize the stored heat-conducting medium to exchange heat with water.

[0015] The renewable energy coupled water electrolysis system of the embodiment of the present invention can realize rapid switching between efficient hydrogen production and hot standby working modes through waste heat recovery and heat storage when wind power and photovoltaic power generation fluctuate, thereby avoiding performance degradation of the electrolyzer equipment caused by continuous start and stop due to random fluctuations of renewable energy, and improving the stability of the system's working performance.

[0016] In some embodiments, the renewable energy coupled water electrolysis system has a hydrogen production mode and a hot standby mode;

[0017] In the hydrogen production mode, the power supply assembly provides electric energy to the water feed pump, the electrolyzer and the electric heater, a portion of the heat-conducting medium heated by the electric heater is transported to the first heat exchanger to exchange heat with water, and the other portion is transported to the heat storage tank for storage;

[0018] In the hot standby mode, the power supply assembly provides electrical energy to the water supply pump, and the heat storage tank transports the stored heat transfer medium to the first heat exchanger to exchange heat with water.

[0019] In some embodiments, the power supply component includes a renewable energy power supply device and an external power supply device, the renewable energy power supply device is connected to the water supply pump, the electrolyzer and the electric heater, and the external power supply device is connected to the water supply pump.

[0020] In some embodiments, the heat conduction component also includes a second heat exchanger, which is arranged on the outlet pipeline of the electrolytic cell and the pipeline from the outlet of the cold storage tank to the electric heater, so as to use the drainage of the electrolytic cell in the second heat exchanger to preheat the heat conduction medium transported from the cold storage tank to the electric heater.

[0021] In some embodiments, the heat conduction component further includes a regulating valve, which is disposed on an outlet pipeline of the electric heater and is used to regulate the flow rate of the heat conduction medium flowing to the heat storage tank and the first heat exchanger.

[0022] In some embodiments, the water electrolysis component also includes an oxygen compressor, an oxygen storage tank, a hydrogen compressor and a hydrogen storage tank. The electrolyzer is connected to the oxygen storage tank via a pipeline and through the oxygen compressor, and the electrolyzer is connected to the hydrogen storage tank via a pipeline and through the hydrogen compressor.

[0023] An embodiment of the present invention further provides a control method for a renewable energy coupled water electrolysis system, and the control method is used for the renewable energy coupled water electrolysis system described in any one of the above embodiments.

[0024] The control method of the renewable energy coupled water electrolysis system according to the embodiment of the present invention includes:

[0025] Determining whether the renewable energy coupled water electrolysis system is operating in a hot standby mode or a hydrogen production mode according to the current input to the electrolyzer;

[0026] When the renewable energy coupled water electrolysis system operates in hot standby mode, the heat transfer medium stored in the heat storage tank is used to heat the water inlet of the electrolytic cell to maintain the temperature of the electrolytic cell;

[0027] When the renewable energy coupled water electrolysis system operates in the hydrogen production mode, the electric heater is used to heat the heat transfer medium, and the heated heat transfer medium is used to exchange heat with the feed water at the inlet of the electrolyzer, and the feed water flow rate of the feed water pump is adjusted at the same time to maintain the operating temperature of the electrolyzer below the maximum limit.

[0028] In some embodiments, when the current input to the electrolyzer is equal to 0A, the renewable energy coupled water electrolysis system operates in hot standby mode.

[0029] In some embodiments, when the renewable energy coupled water electrolysis system operates in a hydrogen production mode, the temperature of the electrolyzer is less than a maximum limit temperature, and the water feed flow rate of the water feed pump is maintained;

[0030] When the renewable energy coupled water electrolysis system operates in hydrogen production mode, the temperature of the electrolyzer is greater than the maximum limit temperature, and the water feed flow rate of the water feed pump is increased to reduce the temperature of the electrolyzer to below the maximum limit temperature.

[0031] In some embodiments, when the renewable energy coupled water electrolysis system operates in the hydrogen production mode, it is determined whether the heat conductive medium stored in the hot storage tank meets the continuous supply when the system operates in the hot standby mode. If not, a part of the heat conductive medium heated by the electric heater is used to heat the water supply to the electrolyzer inlet, and the other part is used to be stored in the hot storage tank. If so, all the heat conductive medium heated by the electric heater is used to heat the water supply to the electrolyzer inlet.

[0032] The control method of the embodiment of the present invention improves the overall efficiency and stability of the system. By adjusting the water supply flow at the inlet of the electrolyzer, the temperature of the electrolyzer is prevented from being too high. The thermal oil adjustment can recover and store the waste heat at the outlet of the electrolyzer. The water electrolysis system can quickly switch between hydrogen production and hot standby modes, providing a new technical path and control method for efficient hydrogen production and stable operation under fluctuating renewable energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of a renewable energy coupled water electrolysis system according to an embodiment of the present invention.

[0034] Figure 2 It is a flow chart of a control method of a renewable energy coupled water electrolysis system according to an embodiment of the present invention.

[0035] Reference numerals:

[0036] 1-renewable energy power supply equipment, 2-electrolyzer, 3-water feed pump, 4-hot storage tank, 5-regulating valve, 6-first heat exchanger, 7-cold storage tank, 8-electric heater, 9-second heat exchanger, 10-water storage tank, 11-oxygen compressor, 12-hydrogen compressor, 13-oxygen storage tank, 14-hydrogen storage tank, 15-external power supply equipment. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0038] The following describes a renewable energy coupled water electrolysis system according to an embodiment of the present invention in conjunction with the accompanying drawings.

[0039] like Figure 1 As shown, the renewable energy coupled water electrolysis system of the embodiment of the present invention includes: a power supply component, a water electrolysis component and a heat conduction component.

[0040] The electrolytic water assembly includes a water storage tank 10, a water supply pump 3 and an electrolyzer 2 (preferably a proton exchange membrane type electrolyzer 2), the outlet of the water storage tank 10 is connected to the inlet of the water supply pump 3 via a pipeline, the outlet of the water supply pump 3 is connected to the water inlet of the electrolyzer 2 via a pipeline, and the drainage outlet of the electrolyzer 2 is connected to the inlet of the water storage tank 10 via a pipeline. The three constitute a circulating water loop, so that the water supply pump 3 extracts water in the water storage tank 10 and supplies it to the electrolyzer 2 for electrolysis of water to produce hydrogen and oxygen, and the drainage of the electrolyzer 2 returns to the water storage tank 10.

[0041] The power supply component is connected to the water supply pump 3 to provide electric energy to the water supply pump 3 and drive the water supply pump 3 to operate. The power supply component is connected to the electrolytic cell 2 to provide electric energy to the electrolytic cell 2 and drive the electrolytic cell 2 to electrolyze water.

[0042] The heat transfer component includes a cold storage tank 7, an electric heater 8, a hot storage tank 4 and a first heat exchanger 6. The outlet of the cold storage tank 7 is connected to the inlet of the electric heater 8 via a pipeline to transport a heat transfer medium (heat transfer oil, etc.) to the electric heater 8 for heating by electric energy. The power supply component is connected to the electric heater 8 to provide electric energy to the electric heater 8.

[0043] The outlet of the electric heater 8 is connected to the inlet of the hot storage tank 4 and the inlet of the cold storage tank 7 via a pipeline, and the first heat exchanger 6 is arranged on the outlet pipeline of the water supply pump 3 and the pipeline from the outlet of the electric heater 8 to the inlet of the cold storage tank 7, so that the heated heat-conducting medium is transported to the hot storage tank 4 for storage, and / or transported to the first heat exchanger 6, so that it exchanges heat with the water transported to the electrolyzer 2 by the water supply pump 3, and the heat-conducting medium after heat exchange and temperature reduction flows back to the cold storage tank 7. The outlet of the hot storage tank 4 is also connected to the inlet of the first heat exchanger 6 via a pipeline, so that the stored heat-conducting medium is used to exchange heat with the inlet water supply of the electrolyzer 2, and flows back to the cold storage tank 7 after heat exchange and temperature reduction. Thus, a circulation loop of the heat-conducting medium is formed.

[0044] The renewable energy coupled water electrolysis system of the embodiment of the present invention has two operating modes: hydrogen production and hot standby. When the system is in hydrogen production mode, the power supply component provides power to the water feed pump 3, the electrolyzer 2 and the electric heater 8, and a part of the heat-conducting medium heated by the electric heater 8 is transported to the first heat exchanger 6 for heat exchange with the inlet water feed of the electrolyzer 2, and the other part is transported to the heat storage tank 4 for storage. When the system is in hot standby mode, the power supply component provides power to the water feed pump 3, and the hot storage tank 4 transports the stored heat-conducting medium to the first heat exchanger 6 for heat exchange with the inlet water feed of the electrolyzer 2.

[0045] Optionally, the power supply component includes a renewable energy power supply device 1 (photovoltaic cells and wind turbine arrays) and an external power supply device 15, the renewable energy power supply device 1 is simultaneously connected to the water pump 3, the electrolyzer 2 and the electric heater 8, and the external power supply device 15 is only connected to the water pump 3.

[0046] It is understandable that when the supply of wind and solar resources is sufficient, the photovoltaic cells and wind turbine arrays generate sufficient electricity, and the electrolyzer 2 has a certain inlet temperature after hot standby, the system can switch to hydrogen production mode. Part of the electric energy generated by the renewable energy power supply equipment 1 is supplied to the electrolyzer 2 to provide electric energy for electrolysis of water to produce hydrogen; part is delivered to the water supply pump 3 for water supply circulation output; part is delivered to the electric heater 8 to heat the heat transfer medium, and the heat transfer medium delivered to the heat storage tank 4 reaches the temperature requirement during hot standby.

[0047] When the supply of wind resources and solar energy resources is insufficient, but the heat transfer medium stored in the heat storage tank 4 can meet the continuous supply in the hot standby mode of the system, the renewable energy power supply device 1 and the electric heater 8 do not work, and the external power supply device 15 provides power to the water pump 3. At this time, the water pump 3 operates in a low energy consumption state, and its outlet water supply volume meets the minimum flow rate of water supply for the electrolyzer 2 during normal operation of hydrogen production. The heat transfer medium stored in the heat storage tank 4 heats the water supply to a certain inlet temperature, maintains the temperature of the electrolyzer 2, and can quickly switch the electrolyzer 2 from the hot standby mode to the hydrogen production mode.

[0048] Therefore, the renewable energy coupled water electrolysis system of the embodiment of the present invention can realize rapid switching between efficient hydrogen production and hot standby working modes through waste heat recovery and heat storage when wind and photovoltaic power generation fluctuate, thereby avoiding performance degradation of the electrolyzer 2 equipment caused by continuous start and stop of renewable energy due to random fluctuations, and improving the stability of the system working performance.

[0049] In some embodiments, Figure 1 As shown, the heat conduction component also includes a second heat exchanger 9, which is arranged on the drainage outlet pipeline of the electrolytic cell 2 and the pipeline from the outlet of the cold storage tank 7 to the inlet of the electric heater 8, so as to use the drainage of the electrolytic cell 2 to preheat the heat conduction medium transported from the cold storage tank 7 to the electric heater 8 in the second heat exchanger 9.

[0050] It is understandable that when the electrolyzer 2 is operating normally to produce hydrogen, the drainage of the electrolyzer 2 contains heat energy, and if it is directly discharged back to the water storage tank 10, this part of the heat energy will be wasted. Therefore, the heat energy in the drainage of the electrolyzer 2 is used to preheat the heat-conducting medium to be heated by the electric heater 8, so as to realize waste heat recovery and improve energy utilization.

[0051] It should be noted that the waste heat recovery process is only carried out when the system operates in hydrogen production mode. When the system operates in hot standby mode, the hot storage tank 4 transports the stored heat transfer medium to the first heat exchanger 6, and flows back to the cold storage tank 7 after heat exchange. At this time, the cold storage tank 7 no longer transports the heat transfer medium to the electric heater 8.

[0052] In some embodiments, Figure 1 As shown, the heat conduction component also includes a regulating valve 5, which is arranged on the outlet pipeline of the electric heater 8, and is used to regulate the flow of the heat conduction medium flowing to the heat storage tank 4 and the first heat exchanger 6.

[0053] That is, the heated heat transfer medium flowing out of the outlet of the electric heater 8 is respectively delivered to the heat storage tank 4 and the first heat exchanger 6 through the regulating valve 5, and the regulating valve 5 is used to regulate the flow of the heat transfer medium delivered to the two.

[0054] In some embodiments, Figure 1 As shown, the water electrolysis component also includes an oxygen compressor 11 , an oxygen storage tank 13 , a hydrogen compressor 12 and a hydrogen storage tank 14 .

[0055] The oxygen outlet of the electrolyzer 2 is connected to the oxygen storage tank 13 through a pipeline and an oxygen compressor 11, so that the oxygen generated by the electrolyzer 2 electrolyzing water is compressed by the oxygen compressor 11 and stored in the oxygen storage tank 13. Similarly, the hydrogen outlet of the electrolyzer 2 is connected to the hydrogen storage tank 14 through a pipeline and a hydrogen compressor 12, so that the hydrogen generated by the electrolyzer 2 electrolyzing water is compressed by the hydrogen compressor 12 and stored in the hydrogen storage tank 14.

[0056] Alternatively, if Figure 1 As shown, the oxygen compressor 11 and the hydrogen compressor 12 are connected to the renewable energy power supply device 1. When the system operates in the hydrogen production mode, part of the electric energy generated by the renewable energy power supply device 1 is provided to the hydrogen compressor 12 and the oxygen compressor 11 for compression and storage of the outlet gas of the electrolyzer 2. When the system operates in the hot standby mode, the hydrogen compressor 12 and the oxygen compressor 11 do not work.

[0057] The following describes a control method for a renewable energy coupled water electrolysis system according to an embodiment of the present invention in conjunction with the accompanying drawings. The control method is applicable to a renewable energy coupled water electrolysis system according to any of the above embodiments.

[0058] like Figure 2 As shown, the control method of the renewable energy coupled water electrolysis system according to the embodiment of the present invention includes:

[0059] According to the current inputted by the electrolyzer 2, it is determined whether the renewable energy coupled water electrolysis system is operating in the hot standby mode or the hydrogen production mode.

[0060] When the renewable energy coupled water electrolysis system operates in hot standby mode, the heat transfer medium stored in the heat storage tank 4 is used to heat the inlet feed water of the electrolyzer 2 to maintain the temperature of the electrolyzer 2 so as to enable the system to quickly switch from hot standby mode to hydrogen production mode.

[0061] When the renewable energy coupled water electrolysis system operates in the hydrogen production mode, the electric heater 8 is used to heat the heat transfer medium, and the heated heat transfer medium is used to exchange heat with the inlet feed water of the electrolyzer 2, and the water feed flow rate of the water feed pump 3 is adjusted at the same time to maintain the operating temperature of the electrolyzer 2 below the maximum limit.

[0062] Optionally, when the supply of wind power and solar energy resources is insufficient and the current input to the electrolyzer 2 is equal to 0A, the system operates in hot standby mode, and the external power supply equipment supplies a small amount of electric energy to the water pump 3 to maintain the minimum water flow at the outlet of the water pump 3 and to meet the normal hydrogen production of the electrolyzer 2 during quick startup. Then, the heat storage tank 4 with the amount of heat transfer medium that meets the continuous supply required for the hot standby of the system transports the stored heat transfer medium to the first heat exchanger 6 to heat the inlet water of the electrolyzer 2 so that the inlet water has a certain inlet temperature. At this time, only the water is circulating in the system.

[0063] Furthermore, when the wind and solar energy resources are in sufficient supply and the current input to the electrolyzer 2 is greater than 0A, the system switches from the hot standby mode to the hydrogen production mode. Since the temperature of the electrolyzer 2 will soon reach the maximum limit temperature (e.g., 80°C) at a certain inlet temperature of the electrolyzer 2, it is determined whether the temperature of the electrolyzer 2 is greater than the maximum limit temperature.

[0064] When the temperature of the electrolytic cell 2 is lower than the maximum limit temperature, the water flow rate of the water pump 3 is maintained, and the heat at the outlet of the electrolytic cell 2 is recovered by the thermal oil, and heated again by the electric heater 8 to make the thermal oil reach the required temperature in the system hot standby mode.

[0065] At this time, the regulating valve 5 is controlled to allow part of the heat transfer oil to enter the heat storage tank 4 for storage, and part of it to heat the water supply at the inlet of the electrolytic cell 2. Finally, it is determined whether the heat transfer medium stored in the heat storage tank 4 meets the continuous supply when the system is running in the hot standby mode. If not, part of the heat transfer medium heated by the electric heater 8 is continuously used to heat the water supply at the inlet of the electrolytic cell 2, and part of it is used to be stored in the heat storage tank 4. If yes, the regulating valve 5 is controlled to allow all of the heat transfer medium heated by the electric heater 8 to be used to heat the water supply at the inlet of the electrolytic cell 2.

[0066] When the temperature of the electrolytic cell 2 is greater than the maximum limit temperature, the power consumption of the water pump 3 is increased, and the water flow rate is increased to stabilize the temperature of the electrolytic cell 2 below the maximum limit temperature. At the same time, the heat transfer oil is used to absorb the heat of the large flow of water at the outlet of the electrolytic cell 2. At this time, it is determined whether the temperature of the heat transfer oil meets the hot standby temperature. If not, it is heated by the electric heater 8. If so, the regulating valve 5 is controlled to allow part of the heat transfer oil to enter the hot storage tank 4 for storage, and part of it is used to heat the water at the entrance of the electrolytic cell 2. Similarly, finally, it is determined whether the hot storage tank 4 meets the continuous supply during hot standby. If not, it continues to store part of it and heat the water at the entrance of the electrolytic cell 2. If so, the regulating valve 5 is controlled to allow the heat transfer oil to only heat the water at the entrance of the electrolytic cell 2.

[0067] In summary, the control method of the renewable energy coupled water electrolysis system of the embodiment of the present invention improves the overall efficiency and stability of the system, and prevents the temperature of the electrolyzer 2 from being too high by adjusting the water supply flow at the inlet of the electrolyzer 2; the thermal oil adjustment can recover and store the waste heat at the outlet of the electrolyzer 2, and the water electrolysis system can quickly switch between the hydrogen production-hot standby mode, providing a new technical path and control method for efficient hydrogen production and stable operation under fluctuating renewable energy.

[0068] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0070] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0072] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0073] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A renewable energy coupled water electrolysis system, characterized in that: include: Power supply components; The water electrolysis component comprises a water storage tank, a water supply pump and an electrolytic cell which are sequentially connected via pipelines, and the power supply component is connected to the water supply pump and the electrolytic cell to provide electrical energy to both; A heat conduction component, the heat conduction component includes a cold storage tank, an electric heater, a hot storage tank and a first heat exchanger, the power supply component is connected to the electric heater to provide electric energy, the outlet of the cold storage tank is connected to the electric heater via a pipeline to transport a heat-conducting medium to the electric heater for heating, the outlet of the electric heater is connected to the hot storage tank and the cold storage tank via a pipeline, the first heat exchanger is arranged on the outlet pipeline of the water supply pump and on the pipeline from the outlet of the electric heater to the cold storage tank, so that the heated heat-conducting medium is transported to the hot storage tank for storage, and / or transported to the first heat exchanger for heat exchange with the water transported by the water supply pump, and the heat-conducting medium after heat exchange flows back to the cold storage tank, and the hot storage tank is connected to the first heat exchanger via a pipeline to utilize the stored heat-conducting medium to exchange heat with water.

2. The renewable energy coupled water electrolysis system according to claim 1, characterized in that: The renewable energy coupled water electrolysis system has a hydrogen production mode and a hot standby mode; In the hydrogen production mode, the power supply assembly provides electric energy to the water feed pump, the electrolyzer and the electric heater, a portion of the heat-conducting medium heated by the electric heater is transported to the first heat exchanger to exchange heat with water, and the other portion is transported to the heat storage tank for storage; In the hot standby mode, the power supply assembly provides electrical energy to the water supply pump, and the heat storage tank transports the stored heat transfer medium to the first heat exchanger to exchange heat with water.

3. The renewable energy coupled water electrolysis system according to claim 2, characterized in that: The power supply assembly includes a renewable energy power supply device and an external power supply device. The renewable energy power supply device is connected to the water supply pump, the electrolyzer and the electric heater, and the external power supply device is connected to the water supply pump.

4. The renewable energy coupled water electrolysis system according to claim 2, characterized in that: The heat conduction component also includes a second heat exchanger, which is arranged on the outlet pipeline of the electrolytic cell and the pipeline from the outlet of the cold storage tank to the electric heater, so as to use the drainage of the electrolytic cell to preheat the heat conduction medium transported from the cold storage tank to the electric heater in the second heat exchanger.

5. The renewable energy coupled water electrolysis system according to claim 2, characterized in that: The heat conduction component further includes a regulating valve, which is disposed on the outlet pipeline of the electric heater and is used to regulate the flow rate of the heat conduction medium flowing to the heat storage tank and the first heat exchanger.

6. The renewable energy coupled water electrolysis system according to claim 2, characterized in that: The water electrolysis component also includes an oxygen compressor, an oxygen storage tank, a hydrogen compressor and a hydrogen storage tank. The electrolyzer is connected to the oxygen storage tank via a pipeline and through the oxygen compressor, and the electrolyzer is connected to the hydrogen storage tank via a pipeline and through the hydrogen compressor.

7. A control method for a renewable energy coupled water electrolysis system, characterized in that: The control method is used for the renewable energy coupled water electrolysis system according to any one of claims 2 to 6, and the control method comprises: Determining whether the renewable energy coupled water electrolysis system is operating in a hot standby mode or a hydrogen production mode according to the current input to the electrolyzer; When the renewable energy coupled water electrolysis system operates in hot standby mode, the heat transfer medium stored in the heat storage tank is used to heat the water inlet of the electrolytic cell to maintain the temperature of the electrolytic cell; When the renewable energy coupled water electrolysis system operates in the hydrogen production mode, the electric heater is used to heat the heat transfer medium, and the heated heat transfer medium is used to exchange heat with the feed water at the inlet of the electrolyzer, and the feed water flow rate of the feed water pump is adjusted at the same time to maintain the operating temperature of the electrolyzer below the maximum limit.

8. The control method of the renewable energy coupled water electrolysis system according to claim 7, characterized in that: When the current input to the electrolyzer is equal to 0A, the renewable energy coupled water electrolysis system operates in hot standby mode.

9. The control method of the renewable energy coupled water electrolysis system according to claim 7, characterized in that: When the renewable energy coupled water electrolysis system operates in a hydrogen production mode, the temperature of the electrolyzer is lower than a maximum limit temperature, and the water feed flow rate of the water feed pump is maintained; When the renewable energy coupled water electrolysis system operates in hydrogen production mode, the temperature of the electrolyzer is greater than the maximum limit temperature, and the water feed flow rate of the water feed pump is increased to reduce the temperature of the electrolyzer to below the maximum limit temperature.

10. The control method of the renewable energy coupled water electrolysis system according to claim 9, characterized in that: When the renewable energy coupled water electrolysis system operates in the hydrogen production mode, it is determined whether the heat-conducting medium stored in the hot storage tank meets the continuous supply when the system operates in the hot standby mode. If not, a part of the heat-conducting medium heated by the electric heater is used to heat the feed water at the electrolyzer inlet, and the other part is stored in the hot storage tank. If so, all of the heat-conducting medium heated by the electric heater is used to heat the feed water at the electrolyzer inlet.

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