Brayton cycle power generation system and method for pulsed operation of a nuclear fusion device

Abstract

The application provides a kind of brayton cycle power generation system and method for pulse operation nuclear fusion device, belongs to the field of fusion device energy conversion technology, constructs the high temperature cladding heat source three path collaborative heating structure, simultaneously meets the main circulation heating, reheating heating and heat storage heating demand;Wherein the heat storage unit is used to replace the cladding main heat source heating path in the suspension stage, realize the change of heat source input path, and the divertor and vacuum chamber low temperature heat source are sequentially introduced into the supercritical carbon dioxide compressor outlet side according to temperature level, coupled with the regenerative system to form a cascade preheating structure, realize the series matching use of low grade heat source.The application utilizes multiple heat sources to generate electricity and store heat during the pulse phase of the fusion reactor, and utilizes heat storage to maintain continuous power generation during the suspension phase.The application solves the problems of single heat source utilization and discontinuous power generation, avoids heat storage temperature decay, reduces the load of the regenerator, and significantly improves the overall heat source utilization efficiency and the service life of the unit.

Description

Technical Field

[0001] This invention belongs to the field of energy conversion technology for fusion devices, specifically relating to a Brayton cycle power generation system and method for pulsed nuclear fusion devices. Background Technology

[0002] With the development of controlled nuclear fusion energy technology, fusion reactors, as advanced energy devices with high energy density, low carbon emissions, and high safety, are gradually moving from the physical experiment stage to the engineering demonstration and commercial application stage. In fusion reactor energy utilization systems, the high-grade thermal energy generated by fusion plasma typically needs to be recovered and utilized through an energy conversion system. This involves converting thermal energy into mechanical energy through a thermodynamic cycle, which then drives a generator to produce electricity, ultimately outputting electrical energy. A stable and efficient thermodynamic cycle power generation system is crucial for realizing fusion energy power generation and directly determines the power output performance of the fusion power plant.

[0003] Steam Rankine cycle power generation systems are the mainstay units in existing thermal power, nuclear power, and solar thermal power plants, characterized by large single-unit capacity and mature and reliable technology. Supercritical carbon dioxide Brayton cycle, as a newer thermodynamic cycle in recent years, exhibits no phase change in its thermodynamic process compared to the steam Rankine cycle. It boasts high power density, a compact structure, and significantly lower unit volume and weight for the same power output compared to steam Rankine cycle units. Furthermore, at operating temperatures above 500℃, its thermoelectric conversion efficiency is typically higher than that of the steam Rankine cycle, with the advantage becoming more pronounced at higher temperatures.

[0004] Currently, magnetic confinement fusion reactors exhibit typical pulsed operation characteristics, such as the EU commercial reactor, which operates for 2.0 hours followed by a 10-minute pause. Furthermore, fusion reactors have multiple heat sources, including blanket heat sources, divertor heat sources, and vacuum chamber heat sources, resulting in a wide temperature range for their output energy (100-600℃). Therefore, achieving continuous and efficient conversion of thermal energy into electrical energy, taking into account the pulsed operation and multi-heat-source output characteristics of fusion reactors, is a key technical challenge for fusion reactor engineering applications.

[0005] Currently, the supercritical carbon dioxide Brayton cycle has significant development potential in fusion reactor energy conversion systems due to its advantages such as high cycle efficiency and compact system. However, most existing Brayton cycle power generation systems are designed for continuous and stable heat sources, with a continuous and stable supply of heat at the inlet of the main heat source heat exchanger. This makes it difficult to adapt to the periodic interruption of the blanket heat source during the pulsed operation of the fusion reactor. When the fusion reactor enters the shutdown phase, the blanket heat source stops outputting heat, and the Brayton cycle main heat source heat exchanger loses its heat supply, making it difficult for the power generation system to maintain continuous operation. Conventional energy storage technologies are mostly used for heat compensation when the heat source is insufficient. Their thermal storage structures cannot cope with the substitution effect of the main heat source during the shutdown phase. Furthermore, their structure of storing heat before supplying heat requires a thermal storage and heat exchange process before the high-temperature heat source enters the power generation system, inevitably reducing the temperature quality of the heat source entering the main cycle. This makes it difficult to balance the utilization efficiency of the high-temperature heat source in the fusion reactor with the power generation efficiency of the Brayton cycle.

[0006] Furthermore, in existing technologies, the heat source of the divertor and the heat source of the vacuum chamber in fusion reactors are usually used as independent waste heat or set up in parallel with the regeneration system. This results in problems such as complex system processes and insufficient matching between heat sources of different temperature levels and supercritical carbon dioxide working fluid, making it difficult to fully leverage the advantages of synergistic utilization of multiple heat sources in fusion reactors.

[0007] For example, Chinese patent application CN202010849117.2 (A supercritical carbon dioxide power cycle system and method for fusion reactors) does not address the pulsed operation characteristics of fusion reactors. The blanket heat source, as the high-temperature heat source in the system, can only meet the main heating requirements of the power generation system. Furthermore, Chinese patent application CN202210930406.4 (Energy conversion system and method for gas-cooled microreactors coupled with energy storage and Brayton cycle), which focuses on nuclear fission, addresses gas-cooled microreactors. Although it considers the charging of the thermal storage system, its power rise and fall operation characteristics are fundamentally different from the pulsed operation / pause mode of fusion reactors. Its energy storage function is used to store excess heat from the reactor loop subsystem during power increases in the gas-cooled microreactor. The heat source medium, after its temperature decreases through a heat exchanger, is coupled with the Brayton cycle subsystem, reducing the temperature quality of the heat source. During power reduction in the gas-cooled microreactor, it replenishes heat in the reactor loop subsystem. This heat replenishment principle involves heating the heat source medium from the fission reactor to compensate for its insufficient heat. However, this heat storage and release principle is not suitable for fusion reactor operations. Firstly, its heat release mode, which involves heating the heat source medium from the fission reactor to compensate for its insufficient temperature, is completely unsuitable for the zero-heat-input conditions during intermittent shutdowns of fusion reactors. This is because the fusion reactor acts as a heat dissipation device with zero heat input, and the flow through the fusion reactor would result in significant heat loss. Secondly, the heat storage method, where the temperature is reduced after passing through the heat exchanger before coupling with the Brayton cycle subsystem, reduces the quality of the high-temperature heat source generated by the fusion reactor. Since the heat source temperature directly determines the power generation efficiency of the Brayton cycle, this ultimately leads to a decrease in the power generation efficiency of the Brayton cycle.

[0008] In summary, fusion reactors exhibit typical pulsed operation and multiple heat source characteristics, with a wide temperature range for their output energy. Efficiently utilizing these multiple heat sources through the Brayton cycle to stably and efficiently convert them into electrical energy is a significant challenge in fusion reactor engineering applications. Existing Brayton cycle power generation technologies cannot handle the pulsed operation characteristics of fusion reactors, and conventional Brayton cycles fail to fully and efficiently utilize various heat sources. Therefore, there is an urgent need for a Brayton cycle power generation system and method for pulsed-operation nuclear fusion devices to achieve multi-functional synergistic utilization of the high-temperature blanket main heat source and cascaded coupling utilization of low-temperature heat sources, thereby improving the overall utilization efficiency of fusion reactor heat sources and enabling continuous and stable power generation of the Brayton cycle system under pulsed operation conditions. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a Brayton cycle power generation system and method for pulsed fusion reactors. Its key difference from existing Brayton cycle and energy storage coupling systems lies in its approach: instead of recovering excess heat under continuous heat source conditions and releasing heat to supplement insufficient power, it addresses the extreme unsteady-state conditions of fusion reactors—"pulsed high heat load input - zero heat input during pauses"—by constructing a three-path coordinated heating structure. During the pulsed operation phase of the fusion reactor, the high-temperature blanket heat source is not used solely for the main heating process but is simultaneously distributed to the main heat source heat exchanger, reheater, and heat storage heat exchanger via parallel branches. This allows the high-grade heat source to directly enter the Brayton cycle main heating path without intermediate heat storage cooling, thus avoiding the weakening of high-temperature heat due to irreversible temperature difference losses in traditional heat storage-reheating modes. The system simultaneously distributes the high-temperature blanket heat source of the fusion reactor to the main heat source heat exchanger, reheater, and thermal storage heat exchanger, forming three parallel heating paths: main heating, reheat supply, and thermal storage charging. This achieves synchronous distribution and efficient utilization of the high-temperature heat source. During intermittent reactor shutdowns, the thermal storage system (including thermal storage heat exchangers, hot tanks, and cold tanks) switches to the blanket heat source heating path, allowing the thermal storage heat exchangers to replace the blanket heat source in providing heat input to the main heat source heat exchanger, thereby maintaining the continuity of the Brayton cycle main heat source inlet conditions. The system does not simply rely on thermal storage as an energy compensation source. Instead of providing energy compensation, the heat source supply path is replaced by a thermal storage heat exchanger, which directly takes over the inlet heat source input of the main heat source heat exchanger. Simultaneously, the heat source from the divertor and the vacuum chamber is sequentially introduced to the outlet side of the supercritical carbon dioxide compressor according to their temperature ranges. This, combined with the regenerative system (including a high-temperature regenerator and a low-temperature regenerator), forms a tiered preheating process, achieving a perfect match between the low-grade heat source and the Brayton cycle. All low-grade heat sources are utilized, reducing system complexity, lowering the heat load demand of the regenerator, and improving the overall utilization efficiency of the fusion reactor's heat source. The divertor and the low-temperature heat source in the vacuum chamber are not used as independent waste heat systems or parallel compensation systems, but are sequentially embedded between the compressor outlet and the regenerative system according to their temperature levels. This achieves a sequential temperature increase of the working fluid after compression, thus completing the tiered utilization of the low-grade heat source without altering the main cycle structure.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A Brayton cycle power generation system for a pulsed nuclear fusion device includes an independent fusion reactor blanket heat source loop, a supercritical carbon dioxide Brayton cycle loop, and a divertor and vacuum chamber heat source loop. The fusion reactor blanket heat source loop includes three parallel heating branches: a main heating path, a reheating path, and a thermal storage path. These branches are coupled to the supercritical carbon dioxide Brayton cycle loop via the main heat source heat exchanger, the reheater, and the thermal storage heat exchanger, respectively. The divertor and vacuum chamber heat source loop is connected in series to the supercritical carbon dioxide system via a first preheating heat exchanger and a second preheating heat exchanger. In the Brayton cycle loop, a cascade preheating structure is formed at the outlet side of the main compressor to achieve series preheating. During the pulse operation phase of the fusion reactor, the fusion reactor blanket heat source simultaneously undertakes the tasks of main heating, reheating, and thermal storage heating. The divertor and vacuum chamber heat sources serve as low-temperature heat sources for the cascade preheating of the working fluid. During the intermittent shutdown phase of the fusion reactor, the fusion reactor blanket heat source stops supplying heat, and the thermal storage heat exchanger in the thermal storage heating path replaces the fusion reactor blanket heat source to provide heat input to the main heat source heat exchanger and reheater, thereby ensuring continuous and stable power generation of the Brayton cycle during the intermittent shutdown phase of the fusion reactor.

[0012] This invention also provides an operation method for a Brayton cycle power generation system of a pulsed nuclear fusion device, including a fusion reactor pulsed operation mode and a fusion reactor intermittent shutdown mode; in the fusion reactor pulsed operation mode, the fusion reactor blanket heat source loop, the supercritical carbon dioxide Brayton cycle loop, and the divertor and vacuum chamber heat source loop operate simultaneously, and the fusion reactor blanket heat source loop and the divertor and vacuum chamber heat source loop simultaneously provide heat, distributing the working fluid from the main compressor outlet to the branches of the first preheating heat exchanger and the second preheating heat exchanger, and then the compressor operates at its rated speed, with the working fluid sequentially passing through the main heat source heat exchanger, After being heated by the reheater, the fuel enters the high-pressure turbine and low-pressure turbine to expand and perform work. In the intermittent shutdown mode of the fusion reactor, the heat source loop of the fusion reactor blanket, the heat source loop of the divertor and the vacuum chamber are closed, and the heat storage and heating path in the supercritical carbon dioxide Brayton cycle loop and the fusion reactor blanket heat source loop switches modes. The heat source loop of the fusion reactor blanket stops supplying heat and switches the working fluid to the branch of the third preheating heat exchanger in the supercritical carbon dioxide Brayton cycle loop, so that the working fluid absorbs low-grade waste heat through the third preheating heat exchanger to maintain the minimum circulation flow and temperature level of the supercritical carbon dioxide Brayton cycle loop.

[0013] Beneficial effects:

[0014] 1. This invention fully leverages the characteristics of the high temperature and large heat power proportion of the fusion reactor blanket heat source to construct a parallel and coordinated heating structure in which the high-temperature blanket heat source simultaneously supplies heat to the main heat source heat exchanger, reheater, and thermal storage heat exchanger. This achieves the distribution of the blanket heat source among different thermal links, improving the flexibility and overall efficiency of the high-temperature heat source utilization. More importantly, during the intermittent shutdown phase of the fusion reactor, the thermal storage system (including thermal storage heat exchanger, hot tank, and cold tank) replaces the blanket heat source in supplying heat to the main heat source heat exchanger by switching the heating path. This ensures continuous heat input conditions at the inlet of the Brayton cycle main heat source, structurally solving the problem of main cycle heat source interruption caused by fusion reactor pulse operation. This achieves continuous and stable operation of the Brayton cycle and reduces system thermal stress and equipment fatigue caused by frequent start-ups and shutdowns.

[0015] 2. The high-temperature cladding heat source constructed in this invention is used simultaneously for main cycle heating, reheating, and thermal storage system charging in a synergistic heating structure. The cladding heat source medium directly enters the main heat source heat exchanger to heat the supercritical carbon dioxide working fluid, enabling the main cycle to fully utilize the high-temperature thermal energy of the cladding heat source. Compared with the existing technology where the high-temperature heat source first enters the thermal storage system and then supplies heat to the power generation system, this invention avoids temperature decay and energy loss caused by multi-stage heat exchange during thermal storage, maintains a high temperature quality of the heat source entering the main cycle, and improves the average heat absorption temperature and thermoelectric conversion efficiency of the cycle.

[0016] 3. This invention fully considers the different temperatures, low heat grade, and heat power ratio of the divertor and vacuum chamber heat sources. Two stages of low-temperature heat sources are sequentially arranged on the main compressor outlet side, forming a series-connected stepped preheating structure with the low-temperature regenerator, achieving staged heating of the supercritical carbon dioxide working fluid. This structure achieves 100% utilization of the low-grade heat source of the fusion reactor, improves the temperature matching between the heat source and the working fluid, and reduces the heat load on the low-temperature regenerator. Simultaneously, it avoids the complex flow distribution and control problems caused by parallel operation of the low-temperature heat source and regenerator in existing technologies, as well as the structural failure risk of the regenerator due to excessive inlet and outlet temperature differences. This simplifies the system operation and control process and improves operational safety. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the Brayton cycle power generation system for a pulsed nuclear fusion device according to the present invention.

[0018] The attached diagrams are labeled as follows: 1-Fusion reactor blanket heat source loop, 11-First three-way valve, 12-First valve, 13-First pump, 14-Fourth valve, 15-Heat storage exchanger, 16-Second three-way valve, 17-Hot tank, 18-Cold tank, 19-Fifth pump, 110-Fifth three-way valve, 111-Fourth three-way valve, 112-Fourth pump, 2-Supercritical carbon dioxide Brayton cycle loop, 21-Main heat source heat exchanger, 22-High pressure turbine, 23-Reheater, 24- 25-Low-pressure turbine, 26-High-temperature regenerator, 27-Low-temperature regenerator, 28-Cooler, 29-Main compressor, 20-Third three-way valve, 210-First preheating heat exchanger, 211-Second preheating heat exchanger, 212-Third preheating heat exchanger, 213-Fifth valve, 214-Recompressor, 215-Sixth valve, 216-Seventh valve, 3-Diverter and vacuum chamber heat source circuit, 31-Second valve, 32-Second pump, 33-Third valve, 34-Third pump. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] like Figure 1 As shown, the present invention provides a Brayton cycle power generation system for a pulsed nuclear fusion device, comprising a fusion reactor blanket heat source circuit 1, a supercritical carbon dioxide Brayton cycle circuit 2, and a divertor and vacuum chamber heat source circuit 3, which are independent of each other.

[0021] The core of the system lies in constructing a heat source path structure based on the pulsed operation of the fusion reactor: the fusion reactor blanket heat source loop 1 forms three parallel heat supply branches: the main heating supply path, the reheat supply path, and the thermal storage supply path; the thermal storage supply path is used to replace the blanket heat source to provide heat input to the main heat source heat exchanger 21 and the reheater 23 during the intermittent shutdown phase of the fusion reactor; the divertor and vacuum chamber heat source loop 3 is used to provide a low-grade heat source to the outlet side of the main compressor 28 to achieve series preheating.

[0022] The fusion reactor blanket heat source loop 1 consists of a first three-way valve 11, a first valve 12, a first pump 13, a fourth valve 14, a thermal storage heat exchanger 15, a second three-way valve 16, a hot tank 17, a cold tank 18, a fifth pump 19, a fifth three-way valve 110, a fourth three-way valve 111, a fourth pump 112, and connecting pipelines. The fusion reactor blanket heat source outlet is connected to the first interface of the first three-way valve 11. The first three-way valve 11, the first valve 12, and the fourth valve 14 cooperate to distribute the blanket heat source among three paths: the heating path of the main heat source heat exchanger 21, the heating path of the reheater 23, and the thermal storage path of the thermal storage heat exchanger 15. The second port of the first three-way valve 11 is connected to the inlet of the first valve 12. The outlet of the first valve 12 is divided into two branches. The first branch is connected to the hot side of the main heat source heat exchanger 21 and is used to provide high-temperature main heating to the supercritical carbon dioxide Brayton cycle. The second branch is connected to the hot side of the reheater 23 and is used to reheat the high-pressure turbine exhaust. The hot-side outlet of the main heat source heat exchanger 21 merges with the hot-side outlet of the reheater 23. The merging pipeline is connected to the inlet of the first pump 13. The outlet of the first pump 13 splits into two branches. The third branch returns to the inlet of the fusion reactor blanket heat source, forming a closed loop. The fourth branch connects to the third port of the second three-way valve 16 for switching the heat storage path during intermittent periods. The third port of the first three-way valve 11 connects to the first port of the fourth valve 14. The second port of the fourth valve 14 connects to the hot-side inlet of the heat storage heat exchanger 15 to form a heat storage and heating path. The hot-side outlet of the heat storage heat exchanger 15 connects to the first port of the second three-way valve 16. The second port of the second three-way valve 16 is connected to the inlet pipeline of the first pump 13. After merging, the pipeline connects to the first pump 13. The system incorporates an inlet to couple and switch the thermal storage system (including thermal storage heat exchanger 15, hot tank 17, and cold tank 18) with the fusion reactor blanket heat source loop 1. The outlet of cold tank 18 connects to the inlet of the fourth pump 112, the outlet of the fourth pump 112 connects to the first port of the fourth three-way valve 111, the second port of the fourth three-way valve 111 connects to the cold-side inlet of thermal storage heat exchanger 15, the cold-side outlet of thermal storage heat exchanger 15 connects to the first port of the fifth three-way valve 110, the second port of the fifth three-way valve 110 connects to the inlet of hot tank 17, the outlet of hot tank 17 connects to the inlet of the fifth pump 19, and the outlet of the fifth pump 19 connects to the third port of the fifth three-way valve 110, participating in the thermal storage / release process through the cold side of thermal storage heat exchanger 15. The third port of the fourth three-way valve 111 connects to the inlet of cold tank 18. The heat storage and supply path is used to store blanket heat source energy during the pulse operation phase of the fusion reactor. During the pause phase, the blanket heat source supply path is taken over by a valve switching structure, and heat input is provided to the main heat source heat exchanger 21 and reheater 23 to maintain the continuous and stable thermal boundary conditions at the inlet of the Brayton cycle main heat source.

[0023] The divertor and vacuum chamber heat source loop 3 consists of a second valve 31, a second pump 32, a third valve 33, a third pump 34, and connecting pipes. The heat source outlet of the fusion reactor divertor is connected to the inlet of the second valve 31. The outlet of the second valve 31 is connected to the hot-side inlet of the second preheating heat exchanger 211. The hot-side outlet of the second preheating heat exchanger 211 is connected to the inlet of the second pump 32. The outlet of the second pump 32 is connected to the heat source inlet of the fusion reactor divertor, thus forming the fusion reactor divertor heat source loop. The heat source outlet of the fusion reactor vacuum chamber is connected to the inlet of the third valve 33. The outlet of the third valve 33 is connected to the hot-side inlet of the first preheating heat exchanger 210. The hot-side outlet of the first preheating heat exchanger 210 is connected to the inlet of the third pump 34. The outlet of the third pump 34 is connected to the heat source inlet of the fusion reactor vacuum chamber, thus forming the fusion reactor vacuum chamber heat source loop. The divertor heat source and the vacuum chamber heat source are arranged sequentially in the preheating path between the outlet of the supercritical carbon dioxide compressor and the regenerative system according to their temperature levels. They are connected in series to heat the working fluid sequentially, rather than in parallel split coupling, so as to achieve full utilization of the divertor heat source and the vacuum chamber heat source.

[0024] Preferably, the fourth valve 14 is a bidirectional valve, and the medium can flow in the forward or reverse direction according to the operating requirements to realize the switching of the heat storage and heating path.

[0025] The supercritical carbon dioxide Brayton cycle loop 2 consists of a main heat source heat exchanger 21, a high-pressure turbine 22, a reheater 23, a low-pressure turbine 24, a high-temperature regenerator 25, a low-temperature regenerator 26, a cooler 27, a main compressor 28, a third three-way valve 29, a first preheating heat exchanger 210, a second preheating heat exchanger 211, a third preheating heat exchanger 212, a fifth valve 213, a re-compressor 214, a sixth valve 215, a seventh valve 216, and connecting pipelines.

[0026] The cold-side outlet of the main heat source heat exchanger 21 is connected to the inlet of the high-pressure turbine 22. The outlet of the high-pressure turbine 22 is connected to the cold-side inlet of the reheater 23. The cold-side outlet of the reheater 23 is connected to the inlet of the low-pressure turbine 24. The outlet of the low-pressure turbine 24 is connected to the hot-side inlet of the high-temperature regenerator 25. The hot-side outlet of the high-temperature regenerator 25 is connected to the hot-side inlet of the low-temperature regenerator 26. The hot-side outlet of the low-temperature regenerator 26 is divided into two branches. The fifth branch is connected to the hot-side inlet of the cooler 27. The hot-side outlet of the cooler 27 is connected to the inlet of the main compressor 28. The outlet of the main compressor 28 is connected to the first port of the third three-way valve 29. The second port of the third three-way valve 29 is connected to the cold-side inlet of the first preheating heat exchanger 210. The cold-side outlet of valve 10 is connected to the cold-side inlet of the second preheating heat exchanger 211. The cold-side outlet of the second preheating heat exchanger 211 is connected to the inlet of the fifth valve 213. The third port of the third three-way valve 29 is connected to the inlet of the third preheating heat exchanger 212. The outlet of the third preheating heat exchanger 212 is connected to the pipeline between the second preheating heat exchanger 211 and the fifth valve 213. The outlet of the fifth valve 213 is connected to the cold-side inlet of the low-temperature regenerator 26. The cold-side outlet of the low-temperature regenerator 26 merges with the outlet of the sixth valve 215 in the sixth branch, and after merging, it connects to the cold-side inlet of the high-temperature regenerator 25. The sixth branch connects to the inlet of the recompressor 214, and the outlet of the recompressor 214 connects to the inlet of the sixth valve 215. The cold-side outlet of the high-temperature regenerator 25 is connected to the cold-side inlet of the main heat source heat exchanger 21. The seventh valve 216 is located between the main heat source heat exchanger 21 and the reheater 23.

[0027] The fusion reactor blanket heat source loop 1 and the supercritical carbon dioxide Brayton cycle loop 2 are coupled at high temperature through the main heat source heat exchanger 21 and the reheater 23; the divertor and the vacuum chamber heat source loop 3 are coupled in series at low temperature through the first preheating heat exchanger 210 and the second preheating heat exchanger 211; the thermal storage heat exchanger 15 replaces the blanket heat source heating path during the pause phase through a valve switching structure, thereby achieving continuous maintenance of the inlet thermal boundary of the Brayton cycle main heat source.

[0028] The present invention also provides an operation method for a Brayton cycle power generation system for a pulsed nuclear fusion device, including a fusion reactor pulsed operation mode and a fusion reactor intermittent shutdown mode:

[0029] 1) In the fusion reactor pulse operation mode, the fusion reactor blanket heat source loop 1, the supercritical carbon dioxide Brayton cycle loop 2, and the divertor and vacuum chamber heat source loop 3 operate simultaneously.

[0030] The third port of the second three-way valve 16, the third port of the fourth three-way valve 111, the third port of the fifth three-way valve 110, and the third port of the third three-way valve 29 are closed. The fifth pump 19 is closed, and the remaining pumps and valves are in the open state.

[0031] For the fusion reactor blanket heat source loop 1, the fusion reactor blanket heat source medium flows out from the outlet and is divided into parallel heat source distribution paths through the first three-way valve 11. The first branch flows through the first valve 12 and then splits into the third and fourth branches. The third branch flows through the hot side of the main heat source heat exchanger 21 to mainly heat the supercritical carbon dioxide in the Brayton cycle. The fourth branch flows through the hot side of the seventh valve 216 and the reheater 23 to reheat the high-pressure turbine exhaust gas, realizing the temperature recovery before the turbine's secondary expansion. After cooling, it flows out and merges with the third branch at the hot side outlet of the main heat source heat exchanger 21, flowing to the first pump 13. The second branch flows through the hot side of the fourth valve 14 and the thermal storage heat exchanger 15 to heat the molten salt in the cold tank, realizing the thermal storage system's heat charging. After the temperature decreases, it flows out through the second port of the second three-way valve 16 and merges with the combined flow of the third and fourth branches, flowing together to the first pump 13, and then returning to the fusion reactor blanket for heating. Low-temperature molten salt flows out of cold tank 18 and flows sequentially through fourth pump 112, fourth three-way valve 111, and the cold side of heat storage heat exchanger 15. After being heated by the cladding heat source medium, the temperature rises to the target temperature and flows into hot tank 17 through fifth three-way valve 110 for heat storage.

[0032] For the divertor and vacuum chamber heat source loop 3, the heat source medium of the divertor and vacuum chamber flows sequentially through the second valve 31, the second pump 32, and the third valve 33 and the third pump 34, respectively, and enters the second preheating heat exchanger 211 and the first preheating heat exchanger 210, respectively, to preheat the supercritical carbon dioxide Brayton cycle working medium in the low-temperature section, realizing the sequential coupling utilization of the low-grade heat source. For the supercritical carbon dioxide Brayton cycle loop 2: after the supercritical carbon dioxide is heated by the main heat source heat exchanger 21, the temperature rises to the target temperature, and it enters the high-pressure turbine 22 to generate electricity. The exhaust flows through the reheater 23 for reheating, increasing the exhaust temperature, and flows into the low-pressure turbine 24 to generate electricity again. The exhaust flows sequentially through the hot side of the high-temperature regenerator 25 and the hot side of the low-temperature regenerator 26. After the temperature decreases, it is divided into the fifth branch and the sixth branch. The fifth branch flows into the cooler 27 for further cooling, and then flows into the main compressor 28 to increase the temperature. The pressure is then applied to the first preheating heat exchanger 210 and the second preheating heat exchanger 211 in sequence, where it is preheated in stages using the heat source of the vacuum chamber and the heat source of the divertor. It then flows through the fifth valve 213 and into the low-temperature regenerator 26 for reheating. The sixth branch flows into the recompressor 214 for compression and pressure increase. After flowing through the sixth valve 215, it merges with the fifth branch at the cold side outlet of the low-temperature regenerator 26. After merging, it flows into the high-temperature regenerator 25 for reheating again, and then into the main heat source heat exchanger 21, where it is heated by the cladding heat source medium and reaches the target temperature.

[0033] 2) In the intermittent shutdown mode of the fusion reactor, the heat source loop 1 of the fusion reactor blanket and the heat source loop 3 of the divertor and vacuum chamber are shut down, and the heat storage and heat supply path in the supercritical carbon dioxide Brayton cycle loop 2 and the heat source loop 1 of the fusion reactor blanket operates in a switching mode, which includes heat storage mode and heat release mode.

[0034] The first port of the first three-way valve 11, the second port of the second three-way valve 16, the first port of the fourth three-way valve 111, the second port of the fifth three-way valve 110, and the second port of the third three-way valve 29 are closed. The second pump 32, the third pump 34, and the fourth pump 112 are closed, while the remaining pumps and valves are open.

[0035] At this point, the thermal storage and heating path switches from thermal storage mode to thermal release mode. High-temperature molten salt flows out from the hot tank 17, sequentially passing through the fifth pump 19, the fifth three-way valve 110, and the thermal storage heat exchanger 15, releasing the stored high-temperature heat to the working fluid side of the fusion reactor blanket heat source loop 1. This maintains the heat on the input side of the main heat source heat exchanger 21 and the reheater 23, ensuring the stable operation of the Brayton cycle. The molten salt, after releasing heat, enters the cold tank 18. For the supercritical carbon dioxide Brayton cycle loop 2: After being heated by the main heat source heat exchanger 21, the supercritical carbon dioxide reaches the target temperature and enters the high-pressure turbine 22 to perform work and drive the motor to generate electricity. The exhaust flows through the reheater 23 for reheating, increasing the exhaust temperature, and flows into the low-pressure turbine 24 to perform work again and drive the motor to generate electricity. The exhaust flows sequentially through the hot side of the high-temperature regenerator 25 and the hot side of the low-temperature regenerator 26. After the temperature decreases, it splits into the fifth branch and the sixth branch. The fifth branch flows into the cooler 27 for further cooling. Then it flows into the main compressor 28 to increase the pressure, and through the third port of the third three-way valve 29 into the third preheating heat exchanger 212 for preheating, and then through the fifth valve 213 into the low-temperature regenerator 26 for reheating; the sixth branch flows into the recompressor 214 for compression and pressure increase, and after flowing through the sixth valve 215, it merges with the fifth branch of the cold side outlet of the low-temperature regenerator 26, and after merging, it flows into the high-temperature regenerator 25 for reheating again, and then flows into the main heat source heat exchanger 21, where it is heated by the cladding heat source medium and reaches the target temperature.

[0036] In summary, this invention employs a Brayton cycle suitable for pulsed fusion reactors. The high-temperature blanket heat source simultaneously forms a parallel heating structure encompassing the main cycle heating path, reheat cycle path, and heat storage path within the same operating cycle. The heat storage system does not function as a traditional energy compensation unit but rather as a replacement unit for the main heat source heating path. During pauses, it takes over the main heat source input function, altering the heat source input path and ensuring continuous heating of the Brayton cycle working fluid throughout the entire cycle. Simultaneously, the divertor and the low-grade heat source from the vacuum chamber are introduced into the compressor outlet side in a series cascade configuration, coupling with the regenerative system to achieve sequential matching and utilization of the low-grade heat source. This reduces system complexity while decreasing the heat load on the high- and low-temperature regenerators, improving overall heat source utilization efficiency, and thus solving the problems of a single function of the blanket heat source and discontinuous power generation.

[0037] Example:

[0038] Using the cladding heat source temperature of 600℃ (providing 2100MW of heat), the divertor heat source temperature of 200℃ (575MW), and the vacuum chamber heat source temperature of 100℃ (25MW) as specific operating conditions, the advantages of this invention in power generation performance are compared and verified. Analysis shows that this invention, by simultaneously supplying heat from the 600°C cladding heat source to the main heat source heat exchanger, reheater, and heat storage heat exchanger, fully utilizes the high-temperature quality to heat the Brayton cycle working fluid to 580°C, and effectively matches and utilizes the divertor and vacuum chamber heat sources, utilizing all 600MW of low-grade heat sources to achieve a total power generation of 1010MW. In contrast, conventional heat storage technology would cause the heat source temperature to drop to 590°C and the working fluid heating temperature to drop to 570°C, reducing the total power generation by 22MW to 988MW. If the divertor and vacuum chamber heat sources are used as independent waste heat sources and not matched with the power generation cycle, the total power generation would be reduced by 48MW to 962MW. Furthermore, the existing technology's parallel connection of the divertor, vacuum chamber heat source, and low-temperature preheater, due to flow diversion, limits the flow rate and can only utilize a portion of the divertor heat source, reducing the total power generation by 18MW to 992MW. The above calculations and analyses fully demonstrate the significant superiority of this invention in multi-source cascade utilization and improving the overall power generation efficiency of the system.

[0039] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A Brayton cycle power generation system for a pulsed nuclear fusion device, characterized in that, It includes independent fusion reactor blanket heat source loops, supercritical carbon dioxide Brayton cycle loops, and divertor and vacuum chamber heat source loops. The fusion reactor blanket heat source loop includes three parallel heating branches: a main heating path, a reheating path, and a thermal storage path. These branches are coupled to the supercritical carbon dioxide Brayton cycle loop via the main heat source heat exchanger, reheater, and thermal storage heat exchanger, respectively. The divertor and vacuum chamber heat source loop is connected in series to the main heat source loop via a first preheating heat exchanger and a second preheating heat exchanger. A stepped preheating structure is formed on the compressor outlet side to achieve series preheating. During the pulse operation phase of the fusion reactor, the fusion reactor blanket heat source simultaneously undertakes the tasks of main heating, reheating, and thermal storage heating. The divertor and vacuum chamber heat source serve as low-temperature heat sources for stepped preheating of the working fluid. During the intermittent shutdown phase of the fusion reactor, the fusion reactor blanket heat source stops supplying heat, and the thermal storage heat exchanger in the thermal storage heating path replaces the fusion reactor blanket heat source to provide heat input to the main heat source heat exchanger and reheater, thereby ensuring continuous and stable power generation of the Brayton cycle during the intermittent shutdown phase of the fusion reactor. The fusion reactor blanket heat source loop includes a first three-way valve, a first valve, a first pump, a fourth valve, a thermal storage heat exchanger, and a second three-way valve. The fusion reactor blanket heat source outlet is connected to the first three-way valve, which, in conjunction with the first and fourth valves, enables the distribution of three paths: the outlet of the first valve is divided into two branches, one connecting to the hot side of the main heat source heat exchanger to provide high-temperature main heating to the supercritical carbon dioxide Brayton cycle, and the other connecting to the hot side of the reheater to reheat the high-pressure turbine exhaust; the fourth valve connects to the inlet of the thermal storage heat exchanger to form a thermal storage heating path, and the outlet of the supercritical carbon dioxide compressor on the hot side merges with the inlet pipeline of the first pump via the second three-way valve.

2. A Brayton cycle power generation system for a pulsed nuclear fusion device according to claim 1, characterized in that, The fusion reactor blanket heat source loop also includes a hot tank, a cold tank, a fifth pump, a fifth three-way valve, a fourth three-way valve, and a fourth pump. The hot-side outlet of the main heat source heat exchanger and the hot-side outlet of the reheater merge and connect to the inlet of the first pump. The outlet of the first pump is divided into a third branch and a fourth branch. The third branch returns to the fusion reactor blanket heat source inlet to form a closed loop. The fourth branch connects to the third port of the second three-way valve for switching the heat storage path during intermittent reactor shutdown. The outlet of the cold tank is connected to the first port of the fourth three-way valve via the fourth pump. The second port of the fourth three-way valve is connected to the cold-side inlet of the heat storage heat exchanger. The cold-side outlet of the heat storage heat exchanger is connected to the first port of the fifth three-way valve. The second port of the fifth three-way valve is connected to the inlet of the hot tank. The outlet of the hot tank is connected to the third port of the fifth three-way valve via the fifth pump and participates in the heat storage and release processes through the cold side of the heat storage heat exchanger. The third port of the fourth three-way valve is connected to the inlet of the cold tank.

3. A Brayton cycle power generation system for a pulsed nuclear fusion device according to claim 2, characterized in that, The divertor and vacuum chamber heat source circuit includes a second valve, a second pump, a third valve, and a third pump; the heat source outlet of the fusion reactor divertor is connected to the heat source inlet of the fusion reactor divertor via the second valve, the hot side of the second preheating heat exchanger, and the second pump; the heat source outlet of the fusion reactor vacuum chamber is connected back to the heat source inlet of the fusion reactor vacuum chamber via the third valve, the hot side of the first preheating heat exchanger, and the third pump.

4. A Brayton cycle power generation system for a pulsed nuclear fusion device according to claim 3, characterized in that, The supercritical carbon dioxide Brayton cycle loop includes a main heat source heat exchanger, a high-pressure turbine, a reheater, a low-pressure turbine, a high-temperature regenerator, a low-temperature regenerator, a cooler, a main compressor, a third three-way valve, a first preheating heat exchanger, a second preheating heat exchanger, a third preheating heat exchanger, a reheater, a fifth valve, a sixth valve, and a seventh valve. The cold-side outlet of the main heat source heat exchanger sequentially passes through the high-pressure turbine, the cold side of the reheater, the low-pressure turbine, the hot side of the high-temperature regenerator, and the hot side of the low-temperature regenerator before branching into a fifth branch and a sixth branch. The fifth branch connects to the first interface of the third three-way valve via the hot side of the cooler and the main compressor. The second port of the third three-way valve connects to the inlet of the fifth valve via the cold side of the first and second preheating heat exchangers. The third port of the third three-way valve merges into the pipeline between the second preheating heat exchanger and the fifth valve via the third preheating heat exchanger. The outlet of the fifth valve connects to the cold side inlet of the low-temperature regenerator. The cold side outlet of the low-temperature regenerator merges with the outlet of the sixth valve in the sixth branch and then connects to the cold side inlet of the high-temperature regenerator. The sixth branch connects to the inlet of the sixth valve via the recompressor. The cold side outlet of the high-temperature regenerator connects to the cold side inlet of the main heat source heat exchanger. The seventh valve is located between the main heat source heat exchanger and the reheater.

5. A method for operating a Brayton cycle power generation system for a pulsed nuclear fusion device according to any one of claims 1-4, characterized in that, This includes a fusion reactor pulse operation mode and a fusion reactor intermittent shutdown mode. In the fusion reactor pulse operation mode, the fusion reactor blanket heat source loop, the supercritical carbon dioxide Brayton cycle loop, and the divertor and vacuum chamber heat source loop operate simultaneously. The fusion reactor blanket heat source loop and the divertor and vacuum chamber heat source loop provide heat simultaneously, distributing the working fluid from the main compressor outlet to the branches of the first and second preheating heat exchangers. The compressor then operates at its rated speed, and the working fluid is heated sequentially by the main heat source heat exchanger and the reheater before entering the high-pressure turbine and the low-pressure turbine. Expansion performs work; in the intermittent shutdown mode of the fusion reactor, the heat source loop of the fusion reactor blanket, the heat source loop of the divertor and the vacuum chamber are closed, and the heat storage and heating path in the supercritical carbon dioxide Brayton cycle loop and the fusion reactor blanket heat source loop switches to the switching mode; the heat source loop of the fusion reactor blanket stops supplying heat and switches the working fluid to the branch of the third preheating heat exchanger in the supercritical carbon dioxide Brayton cycle loop, so that the working fluid absorbs low-grade waste heat through the third preheating heat exchanger to maintain the minimum circulation flow and temperature level of the supercritical carbon dioxide Brayton cycle loop.

6. The operating method according to claim 5, characterized in that, In the intermittent shutdown mode of the fusion reactor, the heat storage heat exchanger in the fusion reactor blanket heat source loop replaces the fusion reactor blanket heat source to supply heat to the main heat source heat exchanger and reheater through heat supply path switching, so that the inlet of the Brayton cycle main heat source maintains continuous heat input conditions, and the supercritical carbon dioxide Brayton cycle loop continues to operate.

7. The operating method according to claim 6, characterized in that, After the working fluid is heated by the main heat source heat exchanger, its temperature rises to the target temperature. It then enters the high-pressure turbine to do work and drive the motor to generate electricity. The exhaust gas flows through the reheater for reheating, which increases the exhaust temperature.

8. The operating method according to claim 7, characterized in that, The working fluid flows into the low-pressure turbine to do work again and drive the motor to generate electricity. The exhaust flows through the hot side of the high-temperature regenerator and the hot side of the low-temperature regenerator in sequence. After the temperature decreases, it is divided into the fifth branch and the sixth branch.

9. The operating method according to claim 8, characterized in that, The working fluid flows into the cooler through the fifth branch for further cooling, then flows into the main compressor to increase its pressure, flows into the third preheating heat exchanger for preheating, and then flows into the low-temperature regenerator for reheating. The working fluid flows into the recompressor through the sixth branch for compression and pressure increase, and then merges with the working fluid in the fifth branch at the cold side outlet of the low-temperature regenerator. After merging, it flows into the high-temperature regenerator for reheating again, and then flows into the main heat source heat exchanger, where it is heated by the fusion reactor blanket heat source medium and reaches the target temperature.

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