Air cooling supercritical carbon dioxide power generation system based on thorium-based molten salt reactor

Abstract

The invention provides an air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor, which is characterized by comprising the thorium-based molten salt reactor as a heat source of supercritical carbon dioxide; the expansion machine comprises a high-temperature supercritical carbon dioxide expansion machine and a medium-temperature supercritical carbon dioxide expansion machine; the heat regenerator comprises a high-temperature heat regenerator and a low-temperature heat regenerator, the medium-temperature supercritical carbon dioxide expansion machine is sequentially communicated with the high-temperature heat regenerator and the low-temperature heat regenerator, the low-temperature heat regenerator is communicated with the high-temperature heat regenerator through a junction station, and the high-temperature heat regenerator is communicated with the thorium-based molten salt reactor; the air cooler is communicated with the low-temperature heat regenerator through a flow divider; and the compressor is used for doing work to generate power and comprises a main compressor and a split-flow compressor.

Description

Technical Field

[0001] This invention relates to the field of energy-saving technology, specifically to an air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor. Background Technology

[0002] Energy is a key factor supporting national development, and energy conservation is an important aspect of energy development. Nuclear energy, due to its high energy density and low carbon emissions, is considered one of the key technologies for addressing climate change and meeting future energy demands. According to the International Atomic Energy Agency's "Global Nuclear Power Capacity Outlook 2050," under a high-growth scenario, global nuclear power capacity will increase to 873 gigawatts by 2050.

[0003] Traditional light water reactors typically operate at around 300°C and use water or gas as coolants, which may lead to the generation of weapon-grade materials and pose a risk of nuclear proliferation, making them extremely dangerous. In contrast, thorium-based molten salt reactor nuclear energy systems, as one of the fourth-generation advanced nuclear energy systems, have the characteristics of high safety, low nuclear waste, high non-proliferation performance, and high economic efficiency, making them an important direction for energy research.

[0004] Supercritical carbon dioxide cycle power generation technology, with its advantages of high efficiency and flexibility, stable cycle, compact system structure and low construction investment, has become a key research direction.

[0005] Supercritical carbon dioxide Brayton cycle systems use air cooling, but tubular air coolers have relatively low heat exchange efficiency. Plate heat exchangers have a compact structure, can provide a large heat transfer area per unit volume, and have a high heat transfer coefficient, more than twice that of tubular heat exchangers. However, they have limited operating pressure and temperature, and a small single-unit processing capacity.

[0006] Therefore, the urgent technical problem to be solved is how to develop new power generation technologies that are efficient, economical, and environmentally friendly, in order to address the electricity needs of water-scarce areas in western my country. Summary of the Invention

[0007] This invention is made to solve the above-mentioned problems, and its purpose is to provide an air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor.

[0008] This invention provides an air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor, characterized by comprising: a thorium-based molten salt reactor as a heat source for supercritical carbon dioxide; an expander for generating electricity, the expander including a high-temperature supercritical carbon dioxide expander and a medium-temperature supercritical carbon dioxide expander, the thorium-based molten salt reactor being sequentially connected to the high-temperature supercritical carbon dioxide expander and the medium-temperature supercritical carbon dioxide expander; a regenerator including a high-temperature regenerator and a low-temperature regenerator, and the medium-temperature supercritical carbon dioxide expander... It is sequentially connected to a high-temperature regenerator and a low-temperature regenerator. The low-temperature regenerator is connected to the high-temperature regenerator via a manifold, and the high-temperature regenerator is connected to a thorium-based molten salt reactor. It also includes an air cooler, which is connected to the low-temperature regenerator via a splitter. Finally, it includes a compressor for generating electricity. The compressor consists of a main compressor and a split compressor. One end of the main compressor is connected to the air cooler, and the other end is connected to the low-temperature regenerator. One end of the split compressor is connected to the low-temperature regenerator via a splitter, and the other end is connected to the high-temperature regenerator via a manifold.

[0009] The air-cooled supercritical carbon dioxide power generation system based on thorium-based molten salt reactor provided by the present invention may also have the following features: wherein the main compressor includes a supercritical carbon dioxide main compressor and a supercritical carbon dioxide re-compressor, and the supercritical carbon dioxide main compressor and the supercritical carbon dioxide re-compressor are connected.

[0010] The air-cooled supercritical carbon dioxide power generation system based on thorium-based molten salt reactor provided by the present invention may also have the following feature: an intercooler is provided between the supercritical carbon dioxide main compressor and the supercritical carbon dioxide re-compressor to cool the supercritical carbon dioxide and reduce the power consumption of the compressor.

[0011] The air-cooled supercritical carbon dioxide power generation system based on thorium-based molten salt reactor provided by the present invention may also have the following feature: wherein the air cooler is a sawtooth plate-fin air cooler, which is used to increase the heat exchange area.

[0012] The air-cooled supercritical carbon dioxide power generation system based on thorium-based molten salt reactor provided by the present invention may also have the following features: wherein the serrated plate-fin air cooler includes: metal plates 63 respectively disposed at the top and bottom of the serrated plate-fin air cooler; a plurality of fins 61 disposed between the metal plates 63 at the top and bottom of the serrated plate-fin air cooler; and sealing strips 62 disposed on both sides of the fins 61 for dividing the fins 61 into a plurality of basic units.

[0013] The air-cooled supercritical carbon dioxide power generation system based on thorium-based molten salt reactor provided by the present invention may also have the following feature: wherein a plurality of fins 61 are arranged in parallel for transferring heat.

[0014] The air-cooled supercritical carbon dioxide power generation system based on thorium-based molten salt reactor provided by the present invention may also have the following feature: wherein the direction of the seal 62 is parallel to the direction of the fin 61.

[0015] The air-cooled supercritical carbon dioxide power generation system based on thorium-based molten salt reactor provided by the present invention may also have the following feature: the sawtooth plate-fin air cooler is equipped with a filter to prevent blockage when the cooling medium is air.

[0016] The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor provided by this invention may also have the following characteristics: supercritical carbon dioxide absorbs heat through the operating thorium-based molten salt reactor, reaching a high-temperature and high-pressure state, and then enters a high-temperature supercritical carbon dioxide expander to generate electricity. After being discharged from the high-temperature supercritical carbon dioxide expander, it enters a medium-temperature supercritical carbon dioxide expander to continue expanding and generating electricity. After being discharged from the medium-temperature supercritical carbon dioxide expander, it flows sequentially through a high-temperature regenerator and a low-temperature regenerator, and then through a splitter to be divided into two paths. One path enters a split compressor to generate electricity, and the other path passes through an air cooler to be cooled by air, then flows into the supercritical carbon dioxide main compressor to generate electricity, then passes through an intercooler, and finally flows into a supercritical carbon dioxide re-compressor. After generating electricity in the supercritical carbon dioxide re-compressor, it returns to the low-temperature regenerator. Finally, the two paths merge in a combiner and flow into the high-temperature regenerator, returning to the thorium-based molten salt reactor.

[0017] The role and effect of invention

[0018] According to the air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor, this invention employs a thorium-based molten salt reactor, a nuclear reactor technology using thorium-232 as fuel. The design and operation of this reactor differ significantly from conventional reactors, offering many unique advantages. It can operate at high temperatures ranging from 700°C to 1000°C; higher temperatures mean higher thermal efficiency, allowing for more efficient conversion into electrical energy. Unlike conventional reactors that use water or gas as coolants, the thorium-based molten salt reactor uses fluoride salts, which are liquid at high temperatures, as a coolant. These molten salts can also dissolve thorium and uranium fuel, forming liquid fuel. The thorium fuel cycle produces less plutonium-239, reducing the generation of weapons-grade materials and improving nuclear nonproliferation safety.

[0019] This invention not only improves reactor thermal efficiency but also simplifies fuel cycling and reduces radioactive waste generation. In terms of safety, as temperature continues to rise, the density of the molten salt within the reactor decreases, thereby reducing the effective collision opportunities with neutrons and causing the reaction rate to automatically decrease. This natural feedback mechanism helps prevent overheating. Simultaneously, the reactor can also transfer fuel from the main reaction zone to a safe storage container through gravity, avoiding the risk of core meltdown. Furthermore, compared to high-pressure water-cooled reactors, molten salt reactors operate at near-atmospheric pressure, significantly reducing the likelihood of accidents caused by pressure vessel rupture. Therefore, thorium-based molten salt reactor technology possesses high thermal efficiency and high safety, making it an important energy application technology.

[0020] The working fluid in a supercritical carbon dioxide Brayton cycle is carbon dioxide. In the supercritical state, the density of carbon dioxide is similar to that of liquid carbon dioxide, but its viscosity is close to that of its gaseous state. Therefore, supercritical carbon dioxide possesses both the high density of a liquid and the low viscosity of a gas. The components of a supercritical carbon dioxide cycle system are compact, with a component volume that is only 1 / 30th that of a traditional steam cycle system, thus improving cycle efficiency while saving on equipment footprint and project costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor, as described in an embodiment of the present invention; and

[0022] Figure 2 This is a schematic diagram of the sawtooth plate-fin air cooler unit in an embodiment of the present invention. Detailed Implementation

[0023] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] To make the technical means, creative features, objectives and effects of this invention easy to understand, the following embodiments, in conjunction with the accompanying drawings, provide a detailed description of the air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor.

[0025] Figure 1This is a schematic diagram of the structure of an air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor in an embodiment of the present invention.

[0026] like Figure 1 As shown, the air-cooled supercritical carbon dioxide power generation system 100 based on a thorium-based molten salt reactor in this embodiment includes a thorium-based molten salt reactor 10, an expander 20, a regenerator 30, an air cooler 60, and a compressor 40. Both the compressor and the expander are connected to a generator 50 for power generation.

[0027] Thorium-based molten salt reactor 10 is a heat source for supercritical carbon dioxide.

[0028] Within a thorium-based molten salt reactor, thorium-232 is a naturally occurring isotope. Although not a fissile material, it can be converted into one by absorbing neutrons. Thorium-232 absorbs a neutron to form thorium-233, which then undergoes beta decay (emitting an electron and an antineutrino) to become protactinium-233. Protactinium-233 further undergoes beta decay to become uranium-233. Uranium-233 is a fissile material that can undergo fission in the reactor, releasing energy and producing new neutrons, thus sustaining the chain reaction and generating a continuous source of heat. The heat generated in the reactor core is produced by the fluoride salt LiF–NaF–BeF2–ThF4–UF4 (41.8%–31.1%–4.6%–).

[0029] The molten salt absorbs 19.95%–2.55% of the water. Its melting point is typically around 550°C and its boiling point is over 1400°C. This means that the reactor can operate at relatively low pressure, avoiding the high-pressure vessel required by traditional water-cooled reactors, thus saving costs.

[0030] The expander 20 is used to generate electricity. The expander 20 includes a high-temperature supercritical carbon dioxide expander 21 and a medium-temperature supercritical carbon dioxide expander 22. The thorium-based molten salt reactor 10 is connected to the high-temperature supercritical carbon dioxide expander 21 and the medium-temperature supercritical carbon dioxide expander 22 in sequence.

[0031] The regenerator 30 includes a high-temperature regenerator 31 and a low-temperature regenerator 32. The medium-temperature supercritical carbon dioxide expander 22 is connected to the high-temperature regenerator 31 and the low-temperature regenerator 32 in sequence. The low-temperature regenerator 32 is connected to the high-temperature regenerator 31 through the manifold 34. The high-temperature regenerator 31 is connected to the thorium-based molten salt reactor 10.

[0032] The air cooler 60 is a sawtooth plate-fin air cooler 60. The air cooler 60 is connected to the low-temperature regenerator 32 through the distributor 33, which can increase the heat exchange area.

[0033] Figure 2 This is a schematic diagram of the sawtooth plate-fin air cooler unit in an embodiment of the present invention.

[0034] like Figure 2 As shown, the sawtooth plate-fin air cooler 60 includes a metal plate 63, several fins 61, a seal 62, and a filter. After being sealed, the seal 62 forms a basic unit. Multiple basic units form the core of the plate-fin heat exchanger. The operating temperature range of the plate-fin heat exchanger is between -20℃ and 800℃. When the cooling medium is air, a filter is installed before the ambient air enters the plate-fin heat exchanger to effectively prevent clogging.

[0035] Metal plates 63 are respectively disposed at the top and bottom of the sawtooth plate-fin air cooler 60.

[0036] Several fins 61 are arranged in parallel between the metal plates 63 at the top and bottom of the serrated plate-fin air cooler 60 for heat transfer.

[0037] Seals 62 are disposed on both sides of fin 61 to divide fin 61 into several basic units, and the direction of seals 62 is parallel to the direction of fin 61.

[0038] The compressor 40 is used to generate electricity. The compressor 40 includes a main compressor and a split compressor 41. One end of the main compressor is connected to the air cooler 60 and the other end is connected to the low-temperature regenerator 32. One end of the split compressor 41 is connected to the low-temperature regenerator 32 through the splitter 33, and the other end is connected to the high-temperature regenerator 31 through the manifold 34.

[0039] The main compressor includes a supercritical carbon dioxide main compressor 42 and a supercritical carbon dioxide re-compressor 44. The supercritical carbon dioxide main compressor 42 and the supercritical carbon dioxide re-compressor 44 are connected. An intercooler 43 is provided between the supercritical carbon dioxide main compressor 42 and the supercritical carbon dioxide re-compressor 44 to cool the supercritical carbon dioxide and reduce the power consumption of the compressor 40.

[0040] Supercritical carbon dioxide absorbs heat in the operating thorium-based molten salt reactor 10, reaching a high-temperature, high-pressure state with temperatures exceeding 700°C. It then enters the high-temperature supercritical carbon dioxide expander 21 to generate electricity. The supercritical carbon dioxide discharged from the high-temperature supercritical carbon dioxide expander 21 reaches a temperature exceeding 400°C and enters the medium-temperature supercritical carbon dioxide expander 22 for further expansion and power generation. The supercritical carbon dioxide discharged from the medium-temperature supercritical carbon dioxide expander 22, after generating power, has its temperature reduced to around 200°C. It then flows sequentially through the high-temperature regenerator 31 and the low-temperature regenerator 32, and subsequently through the distributor 33, splitting into two paths, one of which... One path enters the split compressor 42 to generate electricity, while the other path passes through the sawtooth plate-fin air cooler 60 to be cooled by air. It then flows into the supercritical carbon dioxide main compressor 42 for the first stage of compression to generate electricity. After passing through the intercooler 43 to be cooled by air, it finally flows into the supercritical carbon dioxide re-compressor 44 for further compression to reach a high-pressure state. After generating electricity in the supercritical carbon dioxide re-compressor 44 at high pressure, it returns to the low-temperature regenerator 32. Finally, the two paths merge in the combiner 34 and flow into the high-temperature regenerator 31 for preheating again. It then returns to the thorium-based molten salt reactor 10 for further heating to reach a high-temperature and high-pressure state, completing the cycle.

[0041] The role and effect of the embodiments

[0042] According to the air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor, this invention employs a thorium-based molten salt reactor, a nuclear reactor technology using thorium-232 as fuel. The design and operation of this reactor differ significantly from conventional reactors, offering many unique advantages. It can operate at high temperatures ranging from 700°C to 1000°C; higher temperatures mean higher thermal efficiency, allowing for more efficient conversion into electrical energy. Unlike conventional reactors that use water or gas as coolants, the thorium-based molten salt reactor uses fluoride salts, which are liquid at high temperatures, as a coolant. These molten salts can also dissolve thorium and uranium fuel, forming liquid fuel. The thorium fuel cycle produces less plutonium-239, reducing the generation of weapons-grade materials and improving nuclear nonproliferation safety.

[0043] This invention not only improves reactor thermal efficiency but also simplifies fuel cycling and reduces radioactive waste generation. In terms of safety, as temperature continues to rise, the density of the molten salt within the reactor decreases, thereby reducing the effective collision opportunities with neutrons and causing the reaction rate to automatically decrease. This natural feedback mechanism helps prevent overheating. Simultaneously, the reactor can also transfer fuel from the main reaction zone to a safe storage container through gravity, avoiding the risk of core meltdown. Furthermore, compared to high-pressure water-cooled reactors, molten salt reactors operate at near-atmospheric pressure, significantly reducing the likelihood of accidents caused by pressure vessel rupture. Therefore, thorium-based molten salt reactor technology possesses high thermal efficiency and high safety, making it an important energy application technology.

[0044] The working fluid in a supercritical carbon dioxide Brayton cycle is carbon dioxide. In the supercritical state, the density of carbon dioxide is similar to that of liquid carbon dioxide, but its viscosity is close to that of its gaseous state. Therefore, supercritical carbon dioxide possesses both the high density of a liquid and the low viscosity of a gas. The components of a supercritical carbon dioxide cycle system are compact, with a component volume that is only 1 / 30th that of a traditional steam cycle system, thus improving cycle efficiency while saving on equipment footprint and project costs.

[0045] This invention uses a thorium-based molten salt reactor with an operating temperature range of 550°C to 1400°C. It can operate at relatively low pressure, avoiding the high-pressure vessel required by traditional water-cooled reactors, thereby achieving cost savings.

[0046] This invention utilizes a plate-fin heat exchanger with multiple parallel plates and fins, ensuring efficient heat transfer and resulting in a very high heat exchange efficiency exceeding 90%. The heat exchange area of ​​plate-fin heat exchangers is typically large, reaching several square meters or even more, allowing them to handle large volumes of heat and making them suitable for the heat exchange needs of large-scale chemical and energy industries. Plate-fin heat exchangers also have a wide operating temperature range, adapting to various operating environments and conditions.

[0047] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A thorium-based molten salt reactor-based air-cooled supercritical carbon dioxide power generation system, characterized in that, include: Thorium-based molten salt reactors serve as a heat source for supercritical carbon dioxide; An expander is used to generate electricity. The expander includes a high-temperature supercritical carbon dioxide expander and a medium-temperature supercritical carbon dioxide expander. The thorium-based molten salt reactor is connected in sequence to the high-temperature supercritical carbon dioxide expander and the medium-temperature supercritical carbon dioxide expander. The regenerator includes a high-temperature regenerator and a low-temperature regenerator. The intermediate-temperature supercritical carbon dioxide expander is connected in sequence to the high-temperature regenerator and the low-temperature regenerator. The low-temperature regenerator is connected to the high-temperature regenerator through a manifold. The high-temperature regenerator is connected to the thorium-based molten salt reactor. An air cooler, wherein the air cooler is connected to a low-temperature regenerator via a distributor; and The compressor is used to generate electricity. The compressor includes a main compressor and a split compressor. One end of the main compressor is connected to an air cooler and the other end is connected to a low-temperature regenerator. One end of the split compressor is connected to the low-temperature regenerator through a splitter and the other end is connected to the high-temperature regenerator through a manifold.

2. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to claim 1, characterized in that: in, The main compressor includes a supercritical carbon dioxide main compressor and a supercritical carbon dioxide re-compressor, and the supercritical carbon dioxide main compressor and the supercritical carbon dioxide re-compressor are connected.

3. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to claim 2, characterized in that: in, An intercooler is provided between the supercritical carbon dioxide main compressor and the supercritical carbon dioxide re-compressor to cool the supercritical carbon dioxide and reduce compressor power consumption.

4. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to claim 3, characterized in that: in, The air cooler is a sawtooth plate-fin air cooler, used to increase the heat exchange area.

5. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to claim 3, characterized in that: in, The sawtooth plate-fin air cooler includes... Metal plates are respectively installed at the top and bottom of the serrated plate-fin air cooler; Several fins are arranged between the metal plates at the top and bottom of the serrated plate-fin air cooler; as well as Seals, placed on both sides of the fin, are used to divide the fin into several basic units.

6. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to claim 5, characterized in that: in, The fins are arranged in parallel to transfer heat.

7. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to claim 6, characterized in that: in, The direction of the seal is parallel to the direction of the fin.

8. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to claim 5, characterized in that: in, The sawtooth plate-fin air cooler is equipped with a filter to prevent blockage when the cooling medium is air.

9. The air-cooled supercritical carbon dioxide power generation system based on a thorium-based molten salt reactor according to any one of claims 3-8, characterized in that: in, The supercritical carbon dioxide absorbs heat in the operating thorium-based molten salt reactor, reaching a high temperature and high pressure state. It then enters the high-temperature supercritical carbon dioxide expander to generate electricity. After being discharged from the high-temperature supercritical carbon dioxide expander, it enters the medium-temperature supercritical carbon dioxide expander to continue expanding and generating electricity. After generating electricity, the carbon dioxide discharged from the medium-temperature supercritical carbon dioxide expander flows sequentially through the high-temperature regenerator and the low-temperature regenerator. It then passes through a splitter and is divided into two paths. One path enters the split compressor to generate electricity, while the other path passes through the air cooler to be cooled by air. It then flows into the supercritical carbon dioxide main compressor to generate electricity, then through the intercooler, and finally into the supercritical carbon dioxide re-compressor. After generating electricity in the supercritical carbon dioxide re-compressor, it returns to the low-temperature regenerator. Finally, the two paths merge in the combiner and flow into the high-temperature regenerator, returning to the thorium-based molten salt reactor.

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