Integrated energy system and control method for collaborative operation of nuclear power hydrogen production and hydrogen energy power generation

Abstract

The application discloses a comprehensive energy system and a control method for collaborative operation of nuclear power hydrogen production and hydrogen energy power generation, and belongs to the technical field of comprehensive utilization of nuclear energy. The system comprises a nuclear power generation unit, an electrolytic hydrogen production unit, a hydrogen storage unit, a hydrogen energy power generation unit and a control unit. The control unit collects the power grid load rate in real time, compares the power grid load rate with a preset first threshold L1 and a second threshold L2, and generates a hierarchical control instruction: when the load rate is lower than L1, part of the electric energy of the nuclear power generation unit is distributed to the electrolytic hydrogen production unit for hydrogen production and storage; when the load rate is between L1 and L2, all the electric energy of the nuclear power generation unit is connected to the power grid; and when the load rate is higher than L2, the hydrogen energy power generation unit is started, and the stored hydrogen is combusted to supplement power. The application also preheats electrolytic water by using the waste heat of the steam turbine, realizes heat-electricity-hydrogen triple production collaboration, and significantly improves the power grid load tracking capability and energy utilization efficiency.

Description

Technical Field

[0001] This invention relates to the fields of nuclear energy comprehensive utilization and hydrogen power generation technology, specifically to a comprehensive energy system and control method for the coordinated operation of nuclear power hydrogen production and hydrogen power generation. Background Technology

[0002] Nuclear energy, as a zero-carbon baseload energy source, plays a crucial role in stabilizing power supply in the power system. However, the power grid load exhibits significant peak-valley fluctuations, and nuclear power units, due to safety and economic considerations, are not suitable for frequent load-changing operation. If they are always operated at baseload, a large amount of surplus energy will be generated during off-peak periods, resulting in waste; if they participate in peak shaving, it will affect reactor lifespan and economic efficiency. Therefore, how to flexibly match grid load fluctuations without sacrificing the baseload advantages of nuclear power units has become an urgent technical problem to be solved in the field of comprehensive nuclear energy utilization.

[0003] Existing technologies have proposed a scheme that combines nuclear power with hydrogen production: during periods of low load, surplus electricity is used to electrolyze water to produce hydrogen, storing the excess electricity in the form of chemical energy. However, such schemes generally have limitations. First, there is a lack of a closed-loop energy system. Most solutions only use hydrogen production as a means of energy storage, with the hydrogen stored or used for chemical synthesis, failing to form a complete loop. During peak load periods, the system still needs to rely on other peak-shaving power sources, limiting its autonomous adjustment capabilities. Second, the control strategies are simplistic, often employing simple on / off control or power regulation, lacking a hierarchical collaborative scheduling mechanism based on the real-time grid load rate. Nuclear power generation, electrolytic hydrogen production, and hydrogen power generation units operate independently, making it difficult to achieve dynamic linkage among multiple units. Furthermore, in the specific path of pressurized water reactor coupled with PEM electrolysis, existing technologies often neglect the utilization of waste heat from turbine exhaust: PEM electrolysis is most efficient at 40 to 60°C, but the 40 to 60°C exhaust steam discharged from the pressurized water reactor turbine is usually directly discharged, resulting in wasted heat energy. More importantly, the combination of pressurized water reactor and hydrogen gas turbine is mostly a sequential "hydrogen production first, then power generation" process. The hydrogen gas turbine is only a downstream device for hydrogen production and cannot independently start / stop or adjust power according to real-time changes in grid load, resulting in slow response speed and difficulty in meeting rapid peak-shaving requirements.

[0004] Therefore, in order to solve the above-mentioned technical problems, this application proposes an integrated energy system and control method for the coordinated operation of nuclear power hydrogen production and hydrogen power generation. Summary of the Invention

[0005] To address the aforementioned issues, this invention proposes an integrated energy system and control method for the coordinated operation of nuclear power hydrogen production and hydrogen power generation. By constructing a closed-loop energy cycle of "baseload power generation + off-peak hydrogen production + peak-hour power supplementation" and combining it with an intelligent coordinated scheduling strategy based on graded load rate thresholds, the system achieves organic linkage between nuclear power generation, electrolytic hydrogen production, hydrogen storage, and hydrogen power generation. This significantly improves the system's ability to track and respond to grid load fluctuations while ensuring stable baseload operation of the reactor.

[0006] To achieve the above objectives, on the one hand, the present invention provides the following technical solution: an integrated energy system for the coordinated operation of nuclear power hydrogen production and hydrogen energy power generation, comprising: a nuclear power generation unit, the output of which is respectively connected to an external power grid and an electrolysis hydrogen production unit, for generating electrical energy and thermal energy;

[0007] An electrolysis hydrogen production unit, whose input end is connected to the nuclear power generation unit and whose output end is connected to the hydrogen storage unit, is used to produce hydrogen by electrolyzing water using the electrical and thermal energy provided by the nuclear power generation unit.

[0008] A hydrogen storage unit, whose input is connected to the electrolytic hydrogen production unit and whose output is connected to the hydrogen power generation unit, is used to store the hydrogen produced by the electrolytic hydrogen production unit and supply hydrogen to the hydrogen power generation unit according to the control signal.

[0009] A hydrogen power generation unit, whose input is connected to the hydrogen storage unit and whose output is connected to the external power grid, is used to burn hydrogen to generate electricity and feed it into the external power grid.

[0010] The control unit is electrically connected to the control terminal of the nuclear power generation unit, the control terminal of the electrolysis hydrogen production unit, the control terminal of the hydrogen storage unit, and the control terminal of the hydrogen power generation unit, respectively.

[0011] The control unit collects the real-time load rate of the external power grid in real time, compares the real-time load rate with a preset first threshold L1 and a second threshold L2, and generates hierarchical control instructions based on the comparison results. The hierarchical control instructions include: a first instruction for controlling the nuclear power generation unit to distribute electrical energy to the electrolysis hydrogen production unit; and a second instruction for controlling the start-up or shutdown of the hydrogen power generation unit and the amount of hydrogen supplied by the hydrogen storage unit to the hydrogen power generation unit.

[0012] Preferably, the control unit performs the following hierarchical control:

[0013] Set a first threshold L1 and a second threshold L2, and 0 <L1<L2<100%;

[0014] When the real-time load rate is less than L1, the control unit issues a first command to allocate part of the electrical energy of the nuclear power generation unit to the electrolysis hydrogen production unit, while ensuring that the nuclear power generation unit always operates in base load condition.

[0015] When the real-time load rate is greater than L2, the control unit issues a second command to start the hydrogen power generation unit and dynamically adjusts the amount of hydrogen supplied from the hydrogen storage unit to the hydrogen power generation unit according to the real-time power deficit, so that the hydrogen power generation unit can supplement the power supply to the external power grid.

[0016] When the real-time load rate is between L1 and L2, the control unit issues a third command to stop the operation of the electrolysis hydrogen production unit and feed all the electrical energy of the nuclear power generation unit into the external power grid.

[0017] Preferably, the first threshold L1 has a value range of 40% to 60%, and the second threshold L2 has a value range of 80% to 95%.

[0018] Preferably, the nuclear power generation unit includes a small modular pressurized water reactor, a steam turbine, a condenser, a pump, and a first generator;

[0019] The steam outlet of the small modular pressurized water reactor is connected to the steam inlet of the steam turbine, the rotor shaft of the steam turbine is connected to the rotor shaft of the first generator, the exhaust steam outlet of the steam turbine is connected to the steam inlet of the condenser, the condensate outlet of the condenser is connected to the inlet of the pump, and the outlet of the pump is connected to the feedwater inlet of the small modular pressurized water reactor.

[0020] The power output terminal of the first generator is connected to the external power grid and the power input terminal of the electrolysis hydrogen production unit through a controllable switch K1, and the control terminal of the controllable switch K1 is electrically connected to the control unit.

[0021] Preferably, the condenser is provided with a heat exchange branch, the heat exchange medium inlet of which is connected to the exhaust steam side of the condenser, and the heat exchange medium outlet of which is connected to the heat exchange jacket inlet of the electrolytic hydrogen production unit; the heat exchange jacket outlet of the electrolytic hydrogen production unit is connected to the return water port of the condenser.

[0022] The exhaust steam discharged from the turbine has a temperature of 40 to 60°C. This exhaust steam is preheated through the heat exchange branch and enters the electrolysis water of the electrolysis hydrogen production unit, so that the temperature of the electrolysis water reaches 40 to 60°C.

[0023] Preferably, the electrolytic hydrogen production unit includes a PEM electrolyzer, which is equipped with a heat exchange jacket; the hydrogen storage unit includes a hydrogen storage tank.

[0024] The hydrogen outlet of the PEM electrolyzer is connected to the inlet of the hydrogen storage tank via a pipeline.

[0025] A controllable hydrogen supply valve V1 is provided between the outlet of the hydrogen storage tank and the hydrogen power generation unit. The inlet of the controllable hydrogen supply valve V1 is connected to the outlet of the hydrogen storage tank, and the outlet of the controllable hydrogen supply valve V1 is connected to the gas inlet of the hydrogen power generation unit. The control terminal of the controllable hydrogen supply valve V1 is electrically connected to the control unit.

[0026] Preferably, the hydrogen power generation unit is a Brayton cycle power generation system, including a combustion chamber, a hydrogen gas turbine, a heat exchanger, a compressor, a second generator, and a start / stop relay;

[0027] The air outlet of the compressor is connected to the cold-side inlet of the heat exchanger, and the cold-side outlet of the heat exchanger is connected to the air inlet of the combustion chamber; the hydrogen outlet of the hydrogen storage tank is connected to the hydrogen inlet of the combustion chamber via a controllable hydrogen supply valve V1; the gas outlet of the combustion chamber is connected to the air inlet of the hydrogen gas engine; the rotor shaft of the hydrogen gas engine is connected to the rotor shaft of the second generator; the exhaust port of the hydrogen gas engine is connected to the hot-side inlet of the heat exchanger, and the hot-side outlet of the heat exchanger is vented.

[0028] The power output terminal of the second generator is connected to the external power grid;

[0029] The start / stop relay is connected in series in the start-up circuit of the hydrogen power generation unit, and its control terminal is electrically connected to the control unit.

[0030] Preferably, the nuclear power generation unit is connected to a first generator, and the hydrogen power generation unit is connected to a second generator. The power output terminals of the first generator and the second generator are each independently connected to the grid connection interface of the external power grid.

[0031] The control unit is electrically connected to the control terminal of the controllable switch K1, the control terminal of the controllable hydrogen supply valve V1, and the start / stop relay of the hydrogen power generation unit. The start / stop relay is connected in series in the start-up circuit of the hydrogen power generation unit.

[0032] The control unit controls the controllable switch K1 via pulse width modulation to adjust the power diversion from the first generator to the electrolytic hydrogen production unit. It also controls the start / stop and output power of the second generator by controlling the engagement or disengagement of the start / stop relay and the opening of the controllable hydrogen supply valve V1, so that the hydrogen power generation unit can be used as an independent power regulation unit and can be started / stopped at any time according to load demand.

[0033] Preferably, the control unit also performs the following energy time-shift scheduling:

[0034] When the real-time load rate is less than L1, the control unit simultaneously sends a closing command to the controllable switch K1 and a start command to the electrolytic hydrogen production unit, converting excess nuclear energy into hydrogen energy and storing it in the hydrogen storage tank.

[0035] When the real-time load rate is greater than L2, the control unit issues a start command to the start-stop relay and an opening adjustment command to the controllable hydrogen supply valve V1, and calls the hydrogen energy stored in the hydrogen storage tank to release electric energy through the hydrogen energy power generation unit, forming an energy time-shift scheduling mechanism of "hydrogen production and storage in low valley periods, power supplement by combustion in peak periods".

[0036] On the other hand, the present invention provides a control method for cooperative operation of nuclear power hydrogen production and hydrogen energy power generation, comprising the following steps:

[0037] Step S1: monitoring the load demand of an external power grid in real time by the control unit, and calculating a real-time load rate;

[0038] Step S2: comparing the real-time load rate with a preset first threshold L1 and a preset second threshold L2, wherein 0<L1<L2<100%;

[0039] Step S3: performing hierarchical scheduling according to the comparison result:

[0040] When the real-time load rate < L1: the control unit closes the controllable switch K1 to distribute part of the electric energy of the nuclear power generation unit to the electrolytic hydrogen production unit; meanwhile, exhaust steam is led out from the heat exchange branch of the condenser to preheat the electrolysis water entering the heat exchange jacket of the PEM electrolyzer; the PEM electrolyzer electrolyzes water to produce hydrogen, and sends the hydrogen into the hydrogen storage tank for storage; When L1 ≤ the real-time load rate ≤ L2: the control unit disconnects the controllable switch K1, stops the operation of the electrolytic hydrogen production unit, and feeds all the electric energy of the nuclear power generation unit into the external power grid; When the real-time load rate > L2: the control unit starts the hydrogen energy power generation unit through the start-stop relay, calculates the required hydrogen flow according to the real-time power deficit, adjusts the opening of the controllable hydrogen supply valve V1 to send the hydrogen in the hydrogen storage tank into the combustion chamber according to the calculated flow, and the hydrogen energy power generation unit generates electric energy to be supplementarily fed into the external power grid.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] This invention constructs a complete energy closed loop of "nuclear power baseload generation—off-peak hydrogen production and storage—peak hydrogen supplementation." The nuclear power generation unit maintains stable baseload operation at all times. During off-peak periods, surplus electricity is converted into chemical energy for storage through hydrogen electrolysis. During peak periods, the hydrogen power generation unit releases electricity back to the grid, enabling the system to autonomously complete time-shifted energy scheduling without relying on external peak-shaving power sources, significantly improving the autonomous regulation capability of the integrated energy system. Based on this, this invention proposes a hierarchical collaborative scheduling strategy based on two-level load factor thresholds. The control unit collects the grid load factor in real time and automatically divides the system into three operating intervals: "off-peak hydrogen storage," "stable power supply," and "peak supplementation." It also dynamically controls the actions of the controllable switch K1, the hydrogen supply valve V1, and the start / stop relays, realizing intelligent linkage between the four units: nuclear power generation, hydrogen electrolysis, hydrogen storage, and hydrogen power generation. This invention avoids the safety risks and economic losses caused by frequent reactor load changes while achieving a second-level rapid response to grid load fluctuations. Simultaneously, it fully utilizes the waste heat of low-grade exhaust steam (40-60°C) from the pressurized water reactor turbine, preheating the PEM electrolysis water to its optimal operating temperature range of 40-60°C via a condenser heat exchange branch. This improves hydrogen production efficiency without increasing additional energy consumption, achieving synergistic optimization of the "heat-power-hydrogen" combined production system. Furthermore, the hydrogen power generation unit uses an independent Brayton cycle system connected in parallel to the nuclear power generation unit to the external grid, equipped with independent start / stop relays and a controllable hydrogen supply valve V1. It can start / stop and quickly adjust output power according to the control unit's instructions, providing flexible support to the grid as an independent power regulation unit, overcoming the slow response and high coupling defects of traditional serial timing systems. This invention significantly improves the energy efficiency and load tracking capability of the integrated nuclear energy utilization system while ensuring the safe and economical operation of the nuclear reactor, demonstrating good engineering feasibility and promising prospects for widespread application. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the overall structure of the system of the present invention; Figure 2 This is a flowchart illustrating the hierarchical scheduling process of the control unit of the present invention.

[0044] In the diagram: 1. Small modular pressurized water reactor; 2. Steam turbine; 3. Condenser; 4. Pump; 5. First generator; 6. PEM electrolyzer; 7. Hydrogen storage tank; 8. Combustion chamber; 9. Hydrogen gas turbine; 10. Heat exchanger; 11. Compressor; 12. Second generator. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0046] Please see Figure 1 This embodiment provides an integrated energy system that combines nuclear power hydrogen production and hydrogen power generation, including a nuclear power generation unit, an electrolysis hydrogen production unit, a hydrogen storage unit, a hydrogen power generation unit, and a control unit. This configuration is chosen because single-source nuclear power generation cannot flexibly track grid load fluctuations. By introducing hydrogen energy as an intermediate carrier and setting up an independent hydrogen power generation unit, surplus nuclear energy during off-peak periods can be stored as chemical energy, and then converted into electricity to feed back into the grid during peak periods, forming a closed loop of "electricity → hydrogen → electricity." This allows the system to autonomously regulate grid load without altering the base load operating status of the nuclear reactor.

[0047] Specifically, in this embodiment, the nuclear power generation unit includes a small modular pressurized water reactor (SMR) 1, a steam turbine 2, a condenser 3, a pump 4, and a first generator 5. The steam outlet of the SMR 1 is connected to the steam inlet of the steam turbine 2, the rotor shaft of the steam turbine 2 is connected to the rotor shaft of the first generator 5, the exhaust steam outlet of the steam turbine 2 is connected to the steam inlet of the condenser 3, the condensate outlet of the condenser 3 is connected to the inlet of the pump 4, and the outlet of the pump 4 is connected to the feedwater inlet of the SMR 1. This closed-loop circuit allows for the recycling of reactor coolant, ensuring that the nuclear reactor can continuously and stably output thermal power. The power output terminal of the first generator 5 is connected to the AC input terminal of an AC / DC rectifier module via a controllable switch K1. The DC output terminal of this AC / DC rectifier module is connected to the power input terminal of the PEM electrolyzer 6. The AC / DC rectifier module is used to convert the AC power output from the first generator 5 into the DC power required by the PEM electrolyzer 6. Its specific topology can be selected according to the system power level. The controllable switch K1 uses a power electronic switching device, such as an IGBT, MOSFET, or thyristor. Its control terminal receives a pulse width modulation (PWM) signal from the control unit. The control unit adjusts the duty cycle of the PWM signal to control the on-time ratio of K1 in each switching cycle, thereby continuously adjusting the power flowing from the first generator 5 to the electrolysis hydrogen production unit, achieving stepless adjustment within the range of 0 to rated power. When the PWM duty cycle is 0, K1 is completely off, and the electrolysis hydrogen production unit consumes no power. When the duty cycle is 100%, K1 is fully on, and the shunt power reaches the set maximum value. Intermediate duty cycles correspond to intermediate power values. In this way, the control unit can flexibly distribute the electrical energy generated by the first generator 5 to the grid or the electrolysis hydrogen production unit as needed by controlling K1, achieving precise power shunt.

[0048] Please continue reading. Figure 1 In this embodiment, the hydrogen electrolysis unit includes a PEM electrolyzer 6, which is equipped with a heat exchange jacket. The power input terminal of the PEM electrolyzer 6 is connected to the power output terminal of the first generator 5 via a controllable switch K1 to receive the power required for hydrogen production. The hydrogen storage unit includes a hydrogen storage tank 7. The hydrogen outlet of the PEM electrolyzer 6 is connected to the inlet of the hydrogen storage tank 7 via a pipeline. A controllable hydrogen supply valve V1 is provided between the outlet of the hydrogen storage tank 7 and the hydrogen power generation unit. The inlet of V1 is connected to the outlet of the hydrogen storage tank 7, and the outlet of V1 is connected to the gas inlet of the hydrogen power generation unit. The control terminal of V1 is electrically connected to the control unit. The PEM electrolyzer 6 is used because it has a low operating temperature (40 to 60°C), rapid start-up and shutdown, and high current density, making it very suitable for peak shaving scenarios coupled with pressurized water reactors and requiring frequent start-up and shutdown. The controllable hydrogen supply valve V1 enables the control unit to adjust the hydrogen flow rate entering the hydrogen power generation unit as needed, thereby achieving continuous and adjustable power generation.

[0049] To achieve cascaded utilization of thermal energy, condenser 3 is equipped with a heat exchange branch. The heat medium inlet of this heat exchange branch is connected to the exhaust steam side of condenser 3, and the heat medium outlet is connected to the heat exchange jacket inlet of PEM electrolyzer 6; the heat exchange jacket outlet of PEM electrolyzer 6 is connected to the return water port of condenser 3; a small circulating pump (not shown in the figure) is installed in the heat exchange branch to drive the circulation of exhaust steam condensate or intermediate heat exchange medium, ensuring stable heat transfer; the exhaust steam temperature discharged from turbine 2 is usually 40 to 60°C, while the optimal operating temperature of PEM electrolysis is exactly 40 to 60°C; through this heat exchange branch, the low-grade exhaust steam waste heat that would otherwise be directly discharged from the cooling tower is used to preheat the electrolysis water, raising the temperature of the electrolysis water to 40 to 60°C; the advantage of this setup is that, without consuming additional electrical energy, it significantly reduces the internal resistance of the PEM electrolyzer, improves electrolysis efficiency, achieves synergistic optimization of "heat-electricity-hydrogen" triple production, and reduces hydrogen production power consumption by about 10% to 15%. In actual operation, if the waste heat from the exhaust steam is still insufficient to heat the electrolytic water to above 40°C, the control unit can activate the auxiliary electric heating element (not shown in the figure) inside the PEM electrolytic cell to compensate, ensuring that the electrolysis always operates within the optimal temperature range.

[0050] Please continue reading. Figure 1 The hydrogen power generation unit is a Brayton cycle power generation system, including a combustion chamber 8, a hydrogen gas turbine 9, a heat exchanger 10, a compressor 11, a second generator 12, and a start-stop relay. The air outlet of the compressor 11 is connected to the cold-side inlet of the heat exchanger 10, and the cold-side outlet of the heat exchanger 10 is connected to the air inlet of the combustion chamber 8; the hydrogen outlet of the hydrogen storage tank 7 is connected to the hydrogen inlet of the combustion chamber 8 through a controllable hydrogen supply valve V1; the gas outlet of the combustion chamber 8 is connected to the air inlet of the hydrogen gas turbine 9; the rotor shaft of the hydrogen gas turbine 9 is connected to the rotor shaft of the second generator 12; the exhaust port of the hydrogen gas turbine 9 is connected to the hot-side inlet of the heat exchanger 10, and the hot-side outlet of the heat exchanger 10 is vented; the power output terminal of the second generator 12 is connected to the external power grid; the start-stop relay is connected in series in the start-up circuit of the hydrogen power generation unit, and its control terminal is electrically connected to the control unit. This embodiment uses an independent Brayton cycle instead of being connected in series with a nuclear steam cycle because the independent system can be started and stopped at any time according to the grid command, without being constrained by the operating status of the nuclear reactor. The response speed can reach the second level, which overcomes the shortcomings of the passive operation of the hydrogen gas turbine and the inability to flexibly adjust peak loads in the traditional serial timing of hydrogen production followed by power generation.

[0051] Please continue reading. Figure 1The nuclear power generation unit is connected to a first generator 5, and the hydrogen energy power generation unit is connected to a second generator 12. The first generator 5 and the second generator 12 are each independently connected to a grid connection interface of an external power grid, and are connected to the power grid through respective grid connection switches respectively, so as to ensure a safe and stable grid connection process. The control unit is electrically connected to the control end of the controllable switch K1, the control end of the controllable hydrogen supply valve V1, and the control end of the start-stop relay respectively. This architecture of parallel and independent grid connection of two generators enables the two power generation units to be decoupled from each other and operate independently under the scheduling of the control unit, which not only ensures the stability of the nuclear energy base load, but also endows the hydrogen energy power generation unit with flexibility as an independent power regulation unit.

[0052] The following combines Figure 2 to describe the control method and working principle of the system in detail:

[0053] The control unit monitors the load demand of the external power grid in real time and calculates the real-time load rate. A first threshold L1, which is 50% in this embodiment, and a second threshold L2, which is 90% in this embodiment, are preset in the control unit, and 0<L1<L2<100%. Among them, 50% corresponds to the lower limit of the economic load of the nuclear power plant. When the load is lower than this value, the economic benefit of only relying on electricity sales is poor, and hydrogen production is suitable; 90% corresponds to the early warning load threshold of the power grid, and when it exceeds this value, the backup power supply needs to be started. The control unit compares the real-time load rate with L1 and L2, and executes the following three-level scheduling according to the comparison result.

[0054] When the system is started for the first time, there is no hydrogen reserve in the hydrogen storage tank 7. At this time, if the real-time load rate is lower than L1, the control unit closes K1 normally for hydrogen production and gradually builds up the reserve; if the real-time load rate is higher than L2 when the system is started for the first time, the control unit keeps the hydrogen energy power generation unit in a standby state, and the nuclear power generation unit independently undertakes the power supply, and the hydrogen energy power peak shaving function is activated after the hydrogen production reserve is completed in the subsequent low load period.

[0055] When the real-time load rate < L1, the power grid is in a low load period. The control unit closes the controllable switch K1, and distributes part of the electric energy of the nuclear power generation unit to the PEM electrolyzer 6;

[0056] At the same time, exhaust steam at 40 to 60°C is drawn from the heat exchange branch of the condenser 3, and the electrolytic water entering the heat exchange jacket of the PEM electrolyzer 6 is preheated to 40 to 60°C; the PEM electrolyzer 6 electrolyzes water to produce hydrogen, and sends the hydrogen into the hydrogen storage tank 7 for storage. The purpose of this arrangement is to convert the surplus nuclear energy that cannot be absorbed by the power grid during the low load period into hydrogen energy for storage, avoiding electric energy waste. Due to the adoption of waste steam waste heat preheating, the electrolysis energy consumption is significantly reduced, achieving the dual gain effect of "hydrogen storage in low load periods and waste heat utilization".

[0057] Regarding the allocation of the aforementioned electrical energy, in this embodiment, the control unit controls the on / off duty cycle of the controllable switch K1 by sending a pulse width modulation signal, thereby adjusting the proportion of electrical energy flowing to the PEM electrolyzer 6: Assuming the rated output power of the first generator 5 is Pgen, the control unit sets the duty cycle of the PWM signal to D (0≤D≤1), then the power flowing to the PEM electrolyzer 6 is D×Pgen, and the power flowing to the external power grid is (1-D)×Pgen; when the real-time load rate is lower than L1, the control unit dynamically adjusts the value of D according to the difference between the real-time load rate and L1. The larger the difference, the larger the value of D, so as to make full use of surplus electrical energy to produce hydrogen.

[0058] When L1 ≤ real-time load rate ≤ L2, the power grid is in the normal load range. The control unit disconnects the controllable switch K1, stops the operation of the electrolysis hydrogen production unit, and feeds all the electrical energy of the nuclear power generation unit into the external power grid. At this time, the hydrogen in the hydrogen storage tank 7 is reserved and not used. The system operates in the simplest way to ensure that all nuclear base load is used for grid power supply and energy loss is minimized.

[0059] When the real-time load factor > L2, the power grid is in peak load period. The control unit starts the hydrogen power generation unit through the start / stop relay and dynamically adjusts the hydrogen supply according to the real-time power deficit. Specifically, the control unit first calculates the real-time power deficit ΔP = Pdemand - Pnuclear, where Pdemand is the real-time load demand of the external power grid, and Pnuclear is the rated output power of the first generator 5. Since the nuclear reactor always operates under base load conditions, Pnuclear is a constant value. Then, based on the lower heating value of hydrogen η (120 MJ / kg in this embodiment) and the power generation efficiency of the hydrogen power generation unit ε (0.9 in this embodiment), the required hydrogen mass flow rate Q is calculated according to the formula Q = ΔP / (η × ε). The control unit converts Q into a target opening command according to the pre-calibrated flow characteristic curve of the controllable hydrogen supply valve V1, i.e., the opening-flow correspondence table, and sends an opening control signal to the regulating mechanism of V1. Meanwhile, the control unit detects and feeds back the actual hydrogen flow rate in real time through a mass flow meter installed on the hydrogen supply pipeline. A PID control algorithm is used to adjust the valve opening in a closed loop, ensuring that the actual hydrogen flow rate tracks the target flow rate in real time. This guarantees that the output power of the hydrogen power generation unit accurately matches the real-time power deficit. Hydrogen is mixed and burned with air pressurized by compressor 11 and preheated by heat exchanger 10 in combustion chamber 8. The resulting high-temperature gas drives the hydrogen gas turbine 9, which in turn drives the second generator 12 to generate electricity, supplementing the external power grid. The key effect of this setup is that when the nuclear power generation unit is already at full power output, the hydrogen power generation unit can start up quickly and make up for the power deficit within seconds—from the control unit detecting that the load rate exceeds L2 to the second generator 12 starting to supply power to the grid, the response time is less than or equal to 1 second. This achieves rapid peak-shaving capability of "peak-hour power supplementation and second-level response," while the nuclear reactor always maintains its rated power operation without frequent load changes, overcoming the shortcomings of slow response and high coupling in traditional peak-shaving methods.

[0060] Preferably, the control unit in this embodiment also collects the hydrogen storage signal Sh2 of the hydrogen storage tank 7 in real time, with a preset safety upper limit Smax=95% and a safety lower limit Smin=10%. When the real-time load rate is less than L1 and Sh2≥Smax, the control unit gradually reduces the electrolysis hydrogen production power by reducing the PWM duty cycle of the controllable switch K1 until Sh2 falls below Smax. When the real-time load rate is greater than L2 and Sh2≤Smin, the control unit prohibits the start of the hydrogen power generation unit, sends a hydrogen reserve shortage alarm to the grid, and requests external peak-shaving support.

[0061] Throughout the entire scheduling process, the small modular pressurized water reactor 1 consistently operates at its rated power base load condition, with its output power fluctuation not exceeding ±5% of the rated power, thus ensuring the reactor's safety and economy. The control unit dynamically adjusts the opening of the controllable hydrogen supply valve V1 using a proportional-integral-derivative (PID) control algorithm or a fuzzy control algorithm, enabling the hydrogen power generation unit's output power to track the power deficit in real time. The input to the PID controller is the power deficit deviation e(t) = ΔP actual - ΔP current output, and the output is the valve opening correction value, thereby achieving high-precision power matching.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A comprehensive energy system integrating nuclear power hydrogen production and hydrogen power generation, characterized in that, include: The nuclear power generation unit has its output connected to the external power grid and the electrolysis hydrogen production unit, respectively, to generate electricity and heat. An electrolysis hydrogen production unit, whose input end is connected to the nuclear power generation unit and whose output end is connected to the hydrogen storage unit, is used to produce hydrogen by electrolyzing water using the electrical and thermal energy provided by the nuclear power generation unit. A hydrogen storage unit, whose input is connected to the electrolytic hydrogen production unit and whose output is connected to the hydrogen power generation unit, is used to store the hydrogen produced by the electrolytic hydrogen production unit and supply hydrogen to the hydrogen power generation unit according to the control signal. A hydrogen power generation unit, whose input is connected to the hydrogen storage unit and whose output is connected to the external power grid, is used to burn hydrogen to generate electricity and feed it into the external power grid. The control unit is electrically connected to the control terminal of the nuclear power generation unit, the control terminal of the electrolysis hydrogen production unit, the control terminal of the hydrogen storage unit, and the control terminal of the hydrogen power generation unit, respectively. The control unit collects the real-time load rate of the external power grid, compares the real-time load rate with a preset first threshold L1 and a second threshold L2, and generates hierarchical control instructions based on the comparison results. The hierarchical control instructions include: a first instruction for controlling the nuclear power generation unit to distribute electrical energy to the electrolysis hydrogen production unit; and a second instruction for controlling the start-up or shutdown of the hydrogen power generation unit and the amount of hydrogen supplied by the hydrogen storage unit to the hydrogen power generation unit. The control unit performs the following hierarchical control: Set a first threshold L1 and a second threshold L2, and 0 <L1<L2<100%; When the real-time load rate is less than L1, the control unit issues a first command to allocate part of the electrical energy of the nuclear power generation unit to the electrolysis hydrogen production unit, while ensuring that the nuclear power generation unit always operates in base load condition. When the real-time load rate is greater than L2, the control unit issues a second command to start the hydrogen power generation unit and dynamically adjusts the amount of hydrogen supplied from the hydrogen storage unit to the hydrogen power generation unit according to the real-time power deficit, so that the hydrogen power generation unit can supplement the power supply to the external power grid. When the real-time load rate is between L1 and L2, the control unit issues a third command to stop the operation of the electrolysis hydrogen production unit and feed all the electrical energy of the nuclear power generation unit into the external power grid.

2. The integrated energy system for coordinated operation of nuclear power hydrogen production and hydrogen power generation according to claim 1, characterized in that, The first threshold L1 has a value range of 40% to 60%, and the second threshold L2 has a value range of 80% to 95%.

3. The integrated energy system for coordinated operation of nuclear power hydrogen production and hydrogen power generation according to claim 2, characterized in that, The nuclear power generation unit includes a small modular pressurized water reactor (1), a steam turbine (2), a condenser (3), a pump (4), and a first generator (5). The steam outlet of the small modular pressurized water reactor (1) is connected to the steam inlet of the steam turbine (2), the rotor shaft of the steam turbine (2) is connected to the rotor shaft of the first generator (5), the exhaust steam outlet of the steam turbine (2) is connected to the steam inlet of the condenser (3), the condensate outlet of the condenser (3) is connected to the inlet of the pump (4), and the outlet of the pump (4) is connected to the feedwater inlet of the small modular pressurized water reactor (1). The power output terminal of the first generator (5) is connected to the external power grid and the power input terminal of the electrolysis hydrogen production unit respectively through a controllable switch K1. The control terminal of the controllable switch K1 is electrically connected to the control unit.

4. The integrated energy system for coordinated operation of nuclear power hydrogen production and hydrogen power generation according to claim 3, characterized in that, The condenser (3) is provided with a heat exchange branch, the heat medium inlet of which is connected to the exhaust steam side of the condenser (3), and the heat medium outlet of which is connected to the heat exchange jacket inlet of the electrolytic hydrogen production unit; the heat exchange jacket outlet of the electrolytic hydrogen production unit is connected to the return water port of the condenser (3). The exhaust steam discharged from the turbine (2) has a temperature of 40 to 60°C. The exhaust steam is preheated by the heat exchange branch and enters the electrolysis water of the electrolysis hydrogen production unit, so that the temperature of the electrolysis water reaches 40 to 60°C.

5. The integrated energy system for coordinated operation of nuclear power hydrogen production and hydrogen power generation according to claim 4, characterized in that, The electrolytic hydrogen production unit includes a PEM electrolyzer (6), which is equipped with a heat exchange jacket; the hydrogen storage unit includes a hydrogen storage tank (7). The hydrogen outlet of the PEM electrolyzer (6) is connected to the inlet of the hydrogen storage tank (7) via a pipeline; A controllable hydrogen supply valve V1 is provided between the outlet of the hydrogen storage tank (7) and the hydrogen power generation unit. The inlet of the controllable hydrogen supply valve V1 is connected to the outlet of the hydrogen storage tank (7), and the outlet of the controllable hydrogen supply valve V1 is connected to the gas inlet of the hydrogen power generation unit. The control terminal of the controllable hydrogen supply valve V1 is electrically connected to the control unit.

6. The integrated energy system for coordinated operation of nuclear power hydrogen production and hydrogen power generation according to claim 5, characterized in that, The hydrogen power generation unit is a Brayton cycle power generation system, including a combustion chamber (8), a hydrogen gas turbine (9), a heat exchanger (10), a compressor (11), a second generator (12), and a start / stop relay; The air outlet of the compressor (11) is connected to the cold side inlet of the heat exchanger (10), and the cold side outlet of the heat exchanger (10) is connected to the air inlet of the combustion chamber (8); the hydrogen outlet of the hydrogen storage tank (7) is connected to the hydrogen inlet of the combustion chamber (8) through a controllable hydrogen supply valve V1; the gas outlet of the combustion chamber (8) is connected to the air inlet of the hydrogen gas turbine (9); the rotor shaft of the hydrogen gas turbine (9) is connected to the rotor shaft of the second generator (12); the exhaust port of the hydrogen gas turbine (9) is connected to the hot side inlet of the heat exchanger (10), and the hot side outlet of the heat exchanger (10) is vented. The power output terminal of the second generator (12) is connected to the external power grid; The start / stop relay is connected in series in the start-up circuit of the hydrogen power generation unit, and its control terminal is electrically connected to the control unit.

7. The integrated energy system for coordinated operation of nuclear power hydrogen production and hydrogen power generation according to claim 6, characterized in that, The nuclear power generation unit is connected to a first generator (5), and the hydrogen power generation unit is connected to a second generator (12). The power output terminals of the first generator (5) and the second generator (12) are each independently connected to the grid connection interface of the external power grid. The control unit is electrically connected to the control terminal of the controllable switch K1, the control terminal of the controllable hydrogen supply valve V1, and the start / stop relay of the hydrogen power generation unit. The start / stop relay is connected in series in the start-up circuit of the hydrogen power generation unit. The control unit controls the controllable switch K1 by means of pulse width modulation to adjust the shunt power from the first generator (5) to the electrolytic hydrogen production unit, and adjusts the start-stop and output power of the second generator (12) by controlling the closing or opening of the start-stop relay and the opening of the controllable hydrogen supply valve V1, so that the hydrogen energy power generation unit serves as an independent power regulation unit that can be started, stopped and dispatched at any time according to load requirements.

8. The integrated energy system for coordinated operation of nuclear power hydrogen production and hydrogen power generation according to claim 7, characterized in that, The control unit further performs the following energy time-shift scheduling: When the real-time load rate is less than L1, the control unit issues a closing command to the controllable switch K1 and a start command to the electrolytic hydrogen production unit at the same time, converting excess nuclear energy into hydrogen energy and storing it in the hydrogen storage tank (7); When the real-time load rate is greater than L2, the control unit issues a start command to the start-stop relay and an opening adjustment command to the controllable hydrogen supply valve V1, and calls the hydrogen energy stored in the hydrogen storage tank (7) to release electric energy through the hydrogen energy power generation unit.

9. A control method for an integrated energy system based on the coordinated operation of nuclear power hydrogen production and hydrogen power generation as described in claim 8, characterized in that, It comprises the following steps: Step S1: real-time monitoring of the load demand of the external power grid by the control unit, and calculating the real-time load rate; Step S2: comparing the real-time load rate with a preset first threshold L1 and a preset second threshold L2, wherein 0<L1<L2<100%; Step S3: performing hierarchical scheduling according to the comparison result: When the real-time load rate < L1: the control unit closes the controllable switch K1, and distributes part of the electric energy of the nuclear energy power generation unit to the electrolytic hydrogen production unit; meanwhile, exhaust steam is drawn from the heat exchange branch of the condenser (3) to preheat the electrolytic water entering the heat exchange jacket of the PEM electrolyzer (6); the PEM electrolyzer (6) electrolyzes water to produce hydrogen, and sends the hydrogen into the hydrogen storage tank (7) for storage; When L1 ≤ real-time load rate ≤ L2: the control unit opens the controllable switch K1, stops the operation of the electrolytic hydrogen production unit, and feeds all the electric energy of the nuclear energy power generation unit into the external power grid; When the real-time load rate > L2: the control unit starts the hydrogen energy power generation unit through the start-stop relay, calculates the required hydrogen flow according to the real-time power deficit, adjusts the opening of the controllable hydrogen supply valve V1, and sends the hydrogen in the hydrogen storage tank (7) into the combustion chamber (8) according to the calculated flow, and the hydrogen energy power generation unit generates electric energy to supplement and feed into the external power grid.

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