New energy storage hydrogen production system

Abstract

The invention relates to a new energy energy storage hydrogen production system in the technical field of comprehensive energy, which comprises a new energy power generation unit for providing electric energy, an electrolytic hydrogen production unit for producing hydrogen by electrolyzing water through the electric energy and generating waste heat in the operation process, and a heat energy storage unit for storing energy in the form of heat energy, the complex heat management and coordination control subsystem comprises a heat supply network and a coordination controller; a waste heat outlet of the electrolytic hydrogen production unit, a heat exchange interface of the heat energy storage unit and a feed preheating demand end of the electrolytic hydrogen production unit are in fluid connection through the thermal network; the coordinated controller can realize coordinated management and optimized utilization of heat energy between the electrolytic hydrogen production unit and the heat energy storage unit; according to the system, efficient recovery, storage and reutilization of heat energy in the system are achieved through intelligent heat management and coordination control, and the overall energy efficiency and economical efficiency are improved.

Description

Technical Field

[0001] This invention relates to the field of integrated energy technology, and in particular to a new energy storage and hydrogen production system. Background Technology

[0002] Using renewable energy sources such as wind power and photovoltaics to electrolyze water to produce hydrogen is the mainstream approach to producing "green hydrogen." However, electrolyzers (especially high-temperature solid oxide electrolyzers, SOEC, or alkaline electrolyzers) generate a large amount of medium- and low-temperature waste heat during efficient operation. Traditionally, this waste heat is usually dissipated directly into the environment through cooling systems or transmitted over long distances to residential areas, resulting in energy waste. At the same time, the start-up and maintenance of efficient operation of electrolyzers require a certain amount of heat input (such as preheating the feed water and maintaining the electrolysis temperature), which usually requires additional electricity or fuel to provide. On the other hand, new energy power generation is highly volatile, with a large amount of "curtailed wind and solar power"; existing solutions mostly use electrochemical energy storage (batteries) to time-shift power, but batteries are expensive and have lifespan degradation issues; thermal energy storage, as a large-capacity, low-cost long-term energy storage method, is increasingly valued in power systems, but it usually operates independently and is not deeply integrated with the thermal dynamics of hydrogen production systems. Therefore, how to organically integrate and intelligently coordinate new energy hydrogen production, waste heat recovery, thermal energy storage, and possible electrothermal conversion to build a new type of hydrogen production system with high comprehensive energy utilization efficiency and good operating economy has become a key issue in current technological development. Summary of the Invention

[0003] In order to overcome the shortcomings of the background technology and solve the existing technical problems, this invention discloses a new energy storage hydrogen production system, which realizes the efficient recovery, storage and reuse of thermal energy in the system through intelligent thermal management and coordinated control, thereby improving the overall energy efficiency and economy.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A new energy storage hydrogen production system includes a new energy power generation unit for providing electrical energy, an electrolysis hydrogen production unit for producing hydrogen by electrolyzing water using electrical energy and generating waste heat during operation, a thermal energy storage unit for storing energy in the form of thermal energy, and a thermal management and coordination control subsystem including a thermal network and a coordination controller. The thermal network fluidly connects the waste heat outlet of the electrolysis hydrogen production unit, the heat exchange interface of the thermal energy storage unit, and the feed preheating demand end of the electrolysis hydrogen production unit, forming at least one heat recovery and reuse path. The coordination controller is configured to dynamically adjust the flow direction and flow rate of the heat carrier fluid flowing through the thermal network according to the new energy power generation capacity, the load status of the electrolysis hydrogen production unit, and the temperature and heat storage level of the thermal energy storage unit, so as to realize the coordinated management and optimized utilization of thermal energy between the electrolysis hydrogen production unit and the thermal energy storage unit.

[0005] Furthermore, the control strategies of the coordination controller include a heat preservation mode, a heat storage mode, and a heat release efficiency enhancement mode. In the heat preservation mode, when the electrolytic hydrogen production unit is shut down or under low load, and the thermal energy storage unit needs to maintain its operating temperature, the thermal network is controlled to use part or all of the heat stored in the thermal energy storage unit for circulating heat preservation, or to preheat the feed water and core components of the electrolytic hydrogen production unit. In the heat storage mode, when the electrolytic hydrogen production unit is in operation and its heat generation exceeds the system's real-time heat demand, the thermal network is controlled to direct excess waste heat to the thermal energy storage unit for storage. In the heat release efficiency enhancement mode, when the electrolytic hydrogen production unit starts up or needs to increase its load, the thermal network is controlled to release the heat stored in the thermal energy storage unit to quickly preheat the electrolyzer and increase the feed water temperature, thereby shortening the start-up time and improving operating efficiency.

[0006] Furthermore, the thermal energy storage unit is a thermal storage tank that uses molten salt, thermal oil or phase change material as the thermal storage medium, and has a heat exchanger integrated inside or outside, which is part of the thermal network.

[0007] Furthermore, the thermal network also includes at least one electrothermal conversion device associated with the new energy power generation unit; the coordination controller is also configured to control a portion of the excess electrical energy to be converted into thermal energy through the electrothermal conversion device and stored in the thermal energy storage unit when the new energy power generation is excessive and the electrolysis hydrogen production unit cannot consume it all.

[0008] Furthermore, the thermal network also includes an external heating loop; the coordination controller is also configured to control a portion of the heat to be output to the outside of the system through the external heating loop when the thermal energy storage unit has sufficient heat storage and the internal heat demand of the system is low, for use in district heating or industrial heating.

[0009] Furthermore, the optimization objectives of the control executed by the coordination controller include at least one of the following: minimizing the start-up energy consumption and time of the electrolysis hydrogen production unit, maximizing the overall energy utilization rate of the system, and maximizing the heating revenue based on the heat price signal.

[0010] Furthermore, the system also includes an electric energy storage unit; the coordination controller is an integrated global optimization controller, which is further configured to: coordinately optimize the proportion of the electric energy of the new energy power generation unit to the electrolytic hydrogen production unit, the electric energy storage unit and the electrothermal conversion device according to the new energy power fluctuation, electricity price signal and multi-energy demand, and synchronously optimize the distribution of heat energy flow in the thermal network.

[0011] Furthermore, the system includes the following operating steps: S1, real-time monitoring of new energy power generation, operating status and heat demand of the electrolysis hydrogen production unit, and heat storage status and temperature of the thermal energy storage unit; S2, based on the current operating status and preset optimization targets, the coordination controller decides the current optimal thermal energy management mode and power distribution strategy; S3, executing the decision, controlling the on / off and flow rate of waste heat recovery, heat storage, heat release and external heat supply by adjusting the opening degree and flow direction of pumps and valves in the thermal network; and controlling the start / stop and power of the electrothermal conversion device as needed; S4, in the next control cycle, returning to step S1 for rolling optimization and dynamic adjustment.

[0012] By employing the technical solution described above, the present invention has the following beneficial effects: The new energy storage hydrogen production system disclosed in this invention significantly improves the overall energy efficiency of the system. It recovers and utilizes the originally discarded reaction heat of the electrolyzer for internal preheating or insulation, directly reducing the auxiliary energy consumption in the hydrogen production process and improving the utilization rate of primary energy. It also reduces the operating cost of hydrogen production by using inexpensive thermal energy storage to store the heat energy or waste heat converted from excess electricity from new energy sources, replacing expensive electricity or fossil fuels as the heat source for the system, significantly reducing the energy consumption cost of hydrogen production. Furthermore, it enhances the flexibility and stability of the system. The thermal energy storage can serve as a large-capacity, low-cost "energy buffer" to smooth out fluctuations in new energy sources. The stored thermal energy can ensure the rapid and flexible start-up and shutdown of the electrolyzer and load adjustment, enabling the hydrogen production system to better adapt to intermittent power sources. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the present invention; In the diagram: 1. New energy power generation unit; 2. Electrolysis hydrogen production unit; 3. Thermal energy storage unit; 4. Thermal management and coordination control subsystem; 41. Thermal network; 42. Coordination controller; 5. Electrothermal conversion device. Detailed Implementation

[0014] The technical solution of the present invention will now be described with reference to the accompanying drawings in the embodiments of the present invention.

[0015] Combined with appendix Figure 1 The new energy storage hydrogen production system includes a new energy power generation unit 1 for providing electrical energy, an electrolysis hydrogen production unit 2 for producing hydrogen by electrolyzing water using electrical energy and generating waste heat during operation, a thermal energy storage unit 3 for storing energy in the form of thermal energy, and a thermal management and coordination control subsystem 4 including a thermal network 41 and a coordination controller 42; as needed, the thermal energy storage unit 3 is a thermal storage tank that uses molten salt, heat transfer oil or phase change material as the thermal storage medium, and has a heat exchanger integrated inside or outside, which is part of the thermal network 41; The thermal network 41 fluidly connects the waste heat outlet of the electrolytic hydrogen production unit 2, the heat exchange interface of the thermal energy storage unit 3, and the feed preheating demand end of the electrolytic hydrogen production unit 2, forming at least one heat energy recovery and reuse path. As needed, the thermal network 41 also includes at least one electrothermal conversion device 5 associated with the new energy power generation unit 1. The coordination controller 42 is further configured to, when there is excess new energy power generation and the electrolytic hydrogen production unit 2 cannot fully absorb it, control a portion of the excess electrical energy to be converted into heat energy through the electrothermal conversion device 5 and stored in the thermal energy storage unit 3, thus realizing the coupling and conversion of multiple energy forms such as "electricity-heat-hydrogen". Furthermore, the thermal network 41 also includes an external heating loop. The coordination controller 42 is further configured to, when the thermal energy storage unit 3 has sufficient heat storage and the internal heat demand of the system is low, control a portion of the heat to be output to the outside of the system through the external heating loop for district heating or industrial heating, thus transferring surplus heat energy and creating additional revenue. The coordination controller 42 is configured to dynamically regulate the flow direction and flow rate of the heat transfer fluid flowing through the thermal network 41 based on the new energy power generation capacity, the load status of the electrolysis hydrogen production unit 2, and the temperature and heat storage level of the thermal energy storage unit 3, so as to achieve coordinated management and optimized utilization of thermal energy between the electrolysis hydrogen production unit 2 and the thermal energy storage unit 3. Specifically, the regulation strategy of the coordination controller 42 includes a heat preservation mode, a heat storage mode, and a heat release efficiency enhancement mode. The heat preservation mode is used when the electrolysis hydrogen production unit 2 is in a shutdown or low-load state, and the thermal energy storage unit 3 needs to maintain its operating temperature. In this mode, the thermal network 41 controls the heat storage unit 3 to use part or all of the heat stored in the thermal energy storage unit 3 for circulating heat preservation, or to provide heat to the electrolysis hydrogen production unit 2. The feed water and core components of unit 2 are preheated; in the heat storage mode, when the electrolysis hydrogen production unit 2 is in operation and the heat generation is greater than the real-time heat demand of the system, the thermal network 41 is controlled to guide the excess waste heat to the thermal energy storage unit 3 for storage; in the heat release efficiency enhancement mode, when the electrolysis hydrogen production unit 2 is started or needs to increase the load, the thermal network 41 is controlled to release the heat stored in the thermal energy storage unit 3 to quickly preheat the electrolyzer and increase the feed water temperature, so as to shorten the start-up time and improve the operating efficiency; in addition, the optimization objectives of the control executed by the coordinating controller 42 include: minimizing the start-up energy consumption and time of the electrolysis hydrogen production unit 2, maximizing the overall energy utilization rate of the system, and maximizing the heating revenue according to the heat price signal, at least one of these.

[0016] The system may also include an electric energy storage unit as needed; the coordination controller 42 is an integrated global optimization controller, which is further configured to: coordinately optimize the proportion of the electric power of the new energy power generation unit 1 to the electrolysis hydrogen production unit 2, the electric energy storage unit and the electrothermal conversion device 5 according to the power fluctuation of the new energy source, the electricity price signal and the demand for multiple energy sources, and synchronously optimize the distribution of heat energy flow in the thermal network 41. The global optimization controller performs unified and coordinated optimization of the two energy flows of electricity and heat to achieve optimal system operation under multiple objectives.

[0017] Implementing the new energy storage hydrogen production system described in this invention includes the following operating steps: Step 1: Real-time monitoring of new energy power generation, operating status and heat demand of electrolysis hydrogen production unit 2, and heat storage status and temperature of thermal energy storage unit 3; Step 2: Based on the current operating status and preset optimization goals, the coordination controller 42 decides the optimal thermal energy management mode and power distribution strategy. Step 3: Execute the decision by adjusting the opening and flow direction of the pumps and valves in the thermal network 41 to control the on / off and flow rate of waste heat recovery, heat storage, heat release and external heat supply; and control the start / stop and power of the electrothermal conversion device 5 as needed. Step four: In the next control cycle, return to step one to perform rolling optimization and dynamic adjustment; In specific implementation, the new energy power generation unit 1 (such as a photovoltaic power station) is connected to the DC bus via a converter; the electrolytic hydrogen production unit 2 is an alkaline electrolyzer array, whose coolant outlet is connected to the thermal network 41; the thermal energy storage unit 3 is a dual-tank molten salt thermal storage system (high-temperature tank approximately 380℃, low-temperature tank approximately 290℃); the molten salt circuit exchanges heat with the water circuit of the thermal network 41 through a molten salt-water heat exchanger; the coordination controller 42 of the thermal management and coordination control subsystem 4 receives temperature, flow, and power sensor signals from each unit; the operation process is as follows: During peak solar power generation during the day: the electrolyzer operates at high load, generating a large amount of waste heat; the coordinating controller 42 determines that the system's internal preheating requirements have been met and the molten salt temperature has not reached its upper limit, so it switches to the heat storage mode; it opens the corresponding valves to guide high-temperature cooling water through the molten salt-water heat exchanger, transferring heat to the low-temperature molten salt, and the heated molten salt is pumped into a high-temperature tank for storage; at night, when solar power is zero and before the electrolyzer is scheduled to start: the coordinating controller 42 switches to the heat release and efficiency enhancement mode. It controls the flow of high-temperature molten salt through the heat exchanger to heat the circulating water, and then pumps the hot water into the feed water preheater and the electrolyzer jacket, quickly preheating the system to near the operating temperature, and then powering on to start the system, greatly saving start-up power consumption and time; when the system is shut down for a short period of time: the coordinating controller 42 switches to the heat preservation mode, using the heat storage system to keep the electrolyzer and pipelines at a warm state, avoiding complete cooling.

[0018] The system can be equipped with an electrothermal conversion device 5 (such as an immersion electric heater) and an external heating circuit. When severe solar power curtailment occurs and the electrical energy storage is full, the coordinating controller 42 can activate the electrothermal conversion device 5 to convert excess electrical energy into heat energy and store it in a molten salt thermal storage tank, thus achieving the "thermal" storage of electrical energy. When the thermal energy storage unit 3 has sufficient heat storage and there are nearby heat users (such as factories or residential areas), the coordinating controller 42 can control a portion of the heat flow to be output through the external heating circuit, generating revenue from heat sales. The controller optimizes the production ratio of electricity, heat, and hydrogen based on real-time electricity and heat prices.

[0019] In addition to the new energy power generation, electrolytic hydrogen production, thermal energy storage, and thermal management subsystems, it also includes an electric energy storage unit (such as a lithium battery). The global optimization controller replaces the single coordination controller 42, which simultaneously optimizes the flow of electrical energy and thermal energy. Its optimization objective function comprehensively considers hydrogen sales revenue, heat sales revenue, grid interaction costs (electricity purchase / sales), equipment depreciation costs, etc. In each scheduling cycle, the controller solves the optimal scheduling scheme based on new energy forecasts, electricity price curves, and heat demand forecasts, dynamically deciding how much electricity is used for hydrogen production, how much electricity is stored in batteries, and how much electricity is converted into thermal storage. At the same time, it determines the opening degree of each valve in the thermal network 41, whether to prioritize thermal storage, internal utilization, or external heat supply. This system achieves optimal coordination of multiple energy carriers such as electricity, heat, and hydrogen, maximizing the utilization rate of renewable energy and the overall economic benefits of the project.

[0020] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the above embodiments should be regarded as exemplary and non-limiting in all respects. The scope of this invention is defined by the appended claims rather than the foregoing description. Therefore, it is intended to include all changes that fall within the meaning and scope of the equivalents of the claims within this invention, and no reference numerals in the claims should be regarded as limiting the content of the claims.

Claims

1. A new energy storage hydrogen production system, characterized in that: It includes a new energy power generation unit for providing electricity, an electrolysis hydrogen production unit for producing hydrogen by electrolyzing water using electricity and generating waste heat during operation, a thermal energy storage unit for storing energy in the form of thermal energy, and a thermal management and coordination control subsystem. The thermal management and coordinated control subsystem includes: A thermal network fluidly connects the waste heat outlet of the electrolytic hydrogen production unit, the heat exchange interface of the thermal energy storage unit, and the feed preheating demand end of the electrolytic hydrogen production unit, forming at least one heat energy recovery and reuse path. The coordination controller is configured to dynamically adjust the flow direction and flow rate of the heat carrier fluid flowing through the thermal network based on the power generation of the new energy source, the load status of the electrolysis hydrogen production unit, and the temperature and heat storage level of the thermal energy storage unit, so as to realize the coordinated management and optimized utilization of thermal energy between the electrolysis hydrogen production unit and the thermal energy storage unit.

2. The new energy storage hydrogen production system according to claim 1, characterized in that: The control strategies of the coordination controller include a heat preservation mode, a heat storage mode, and a heat release efficiency enhancement mode. In the heat preservation mode, when the electrolytic hydrogen production unit is shut down or under low load, and the thermal energy storage unit needs to maintain its operating temperature, the thermal network is controlled to use part or all of the heat stored in the thermal energy storage unit for circulating heat preservation, or to preheat the feed water and core components of the electrolytic hydrogen production unit. In the heat storage mode, when the electrolytic hydrogen production unit is in operation and its heat generation exceeds the system's real-time heat demand, the thermal network is controlled to direct excess waste heat to the thermal energy storage unit for storage. In the heat release efficiency enhancement mode, when the electrolytic hydrogen production unit starts up or needs to increase its load, the thermal network is controlled to release the heat stored in the thermal energy storage unit to quickly preheat the electrolyzer and increase the feed water temperature, thereby shortening the start-up time and improving operating efficiency.

3. The new energy storage hydrogen production system according to claim 1 or 2, characterized in that: The thermal energy storage unit is a thermal storage tank that uses molten salt, thermal oil or phase change material as the thermal storage medium, and has a heat exchanger integrated inside or outside, which is part of the thermal network.

4. The new energy storage hydrogen production system according to claim 3, characterized in that: The thermal network also includes at least one electrothermal conversion device associated with the new energy power generation unit; the coordination controller is further configured to control a portion of the excess electrical energy to be converted into thermal energy through the electrothermal conversion device and stored in the thermal energy storage unit when the new energy power generation is excessive and the electrolysis hydrogen production unit cannot consume it all.

5. The new energy storage hydrogen production system according to claim 1, characterized in that: The thermal network also includes an external heating loop; the coordination controller is further configured to control a portion of the heat to be output to the outside of the system through the external heating loop when the thermal energy storage unit has sufficient heat storage and the internal heat demand of the system is low, for use in district heating or industrial heating.

6. The new energy storage hydrogen production system according to claim 1, characterized in that: The optimization objectives of the control executed by the coordination controller include at least one of the following: minimizing the start-up energy consumption and time of the electrolysis hydrogen production unit, maximizing the overall energy utilization rate of the system, and maximizing the heating revenue based on the heat price signal.

7. The new energy storage hydrogen production system according to claim 1, characterized in that: The system also includes an electric energy storage unit; the coordination controller is an integrated global optimization controller, which is further configured to: coordinately optimize the proportion of the electric energy of the new energy power generation unit to the electrolytic hydrogen production unit, the electric energy storage unit and the electrothermal conversion device according to the power fluctuation of the new energy source, the electricity price signal and the demand for multiple energy sources, and synchronously optimize the distribution of heat energy flow in the thermal network.

8. The new energy storage hydrogen production system according to claim 1, Its characteristics include the following operating steps: S1. Real-time monitoring of new energy power generation, operating status and heat demand of electrolytic hydrogen production unit, and heat storage status and temperature of thermal energy storage unit. S2. Based on the current operating status and preset optimization goals, the coordination controller decides the optimal thermal energy management mode and power distribution strategy. S3. Execute decisions by adjusting the opening and flow direction of pumps and valves in the thermal network to control the on / off and flow rate of waste heat recovery, heat storage, heat release, and external heat supply; and control the start / stop and power of the electrothermal conversion device as needed. S4. In the next control cycle, return to step S1 to perform rolling optimization and dynamic adjustment.

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