Nuclear power source

Abstract

The embodiment of the present application provides a nuclear power source, comprising a reactor core, the reactor core comprising a plurality of thermionic fuel elements, each of which forms a coolant channel inside for flowing of a coolant, the nuclear power source further comprising: a coolant loop for receiving the coolant from the coolant channel and circulating the coolant back to the coolant channel; a plurality of heat transfer heat pipes, an evaporation section of each of the heat transfer heat pipes being in heat conduction connection with the coolant loop; a plurality of thermoelectric conversion modules, each of the thermoelectric conversion modules being in heat conduction connection with a condensation section of one of the heat transfer heat pipes to convert heat transmitted by the heat transfer heat pipe into electric energy. The embodiment of the present application utilizes the coolant loop to lead heat of the thermionic fuel elements out of the reactor core, utilizes the heat transfer heat pipe to exchange heat with the coolant loop, and then utilizes the thermoelectric conversion element to convert heat conducted by the heat transfer heat pipe into electric energy, so that the reactor simultaneously adopts thermionic conversion and other thermoelectric conversion, and the thermoelectric conversion efficiency of the reactor power source can be greatly improved.

Description

Technical Field

[0001] This invention relates to the field of nuclear reactor technology, and in particular to a nuclear power source. Background Technology

[0002] Nuclear power sources can be applied in the aerospace field. They generate heat in the reactor core and convert it into electricity to power spacecraft, freeing them from dependence on solar energy. Typically, nuclear power sources utilize only one thermoelectric conversion element to convert the reactor core's heat into electricity, resulting in low power output. Summary of the Invention

[0003] To address the aforementioned technical problems, embodiments of this application provide a nuclear power source.

[0004] The nuclear power source of this application embodiment includes a reactor core, which includes multiple thermionic fuel elements. Each thermionic fuel element has a coolant channel inside for coolant flow. The nuclear power source also includes: a coolant circuit for receiving coolant from the coolant channel and circulating the coolant back to the coolant channel; multiple heat transfer tubes, the evaporation section of each heat transfer tube being thermally connected to the coolant circuit; and multiple sets of thermoelectric conversion modules, each set of thermoelectric conversion modules being thermally connected to the condensation section of a heat transfer tube to convert the heat transferred by the heat transfer tube into electrical energy.

[0005] This application embodiment utilizes a coolant circuit to remove heat from the thermionic fuel element from the reactor, uses heat transfer tubes to exchange heat with the coolant circuit, and then uses thermoelectric conversion elements to convert the heat conducted by the heat transfer tubes into electrical energy. This allows the reactor to simultaneously employ thermionic conversion and other thermoelectric conversions, which can significantly improve the thermoelectric conversion efficiency of the reactor power supply. Attached Figure Description

[0006] Other objects and advantages of the invention will become apparent from the following description of the invention with reference to the accompanying drawings, and will help to provide a comprehensive understanding of the invention.

[0007] Figure 1 This is a schematic diagram of the structure of a nuclear power source according to an embodiment of this application;

[0008] Figure 2 yes Figure 1 A front view of the nuclear power source shown;

[0009] Figure 3 This is a schematic cross-sectional view of the core of a nuclear power source according to an embodiment of this application;

[0010] Figure 4 yes Figure 1 A partially enlarged schematic diagram of the nuclear power source shown.

[0011] Figure 5 yes Figure 1 The diagram shows a nuclear power source in which a support frame is used to connect the heat transfer heat pipe and the heat dissipation heat pipe.

[0012] Figure 6 yes Figure 5 The cross-sectional view of the structure shown is provided, but the support frame is omitted in the figure.

[0013] Figure 7 yes Figure 1 The diagram shows a cross-sectional view of the heat transfer heat pipes and the annular piping connection in the nuclear power source.

[0014] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding.

[0015] Explanation of reference numerals in the attached figures:

[0016] 10. Core; 11. Thermoion fuel element; 12. First collector cavity; 13. Second collector cavity; 14. Shielding; 15. Control drum drive mechanism; 16. Control drum; 17. Radial reflector layer; 18. Solid moderator;

[0017] 21. Pump; 22. Volume compensator; 201. Coolant inlet pipeline; 202. Coolant outlet pipeline;

[0018] 30. Ring pipeline;

[0019] 40. Heat transfer heat pipe; 50. Heat dissipation heat pipe; 51. Body section; 52. Annular joint section;

[0020] 60. Support frame; 61. First hollowed-out plate; 611. Inner ring; 612. Outer ring; 613. Connecting rod; 62. Second hollowed-out plate; 63. Support rod;

[0021] 70. Heat sink;

[0022] 80. Thermoelectric conversion element;

[0023] 90. Insulating and heat-insulating components. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. Obviously, the described embodiments are one embodiment of this invention, and not all embodiments. Based on the described embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0025] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0026] In the description of the embodiments of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] The thermionic fuel cell has a very precise structure. Typically, from the inside out, the thermionic fuel cell consists of: fuel, emitter, generator gap, receiver, electrical insulation, helium chamber, stainless steel inner tube wall, coolant, and stainless steel outer tube wall. The coolant is usually a sodium-potassium alloy. During operation, the emitter temperature reaches approximately 1800K, far exceeding the receiver temperature. Electrons are released from the emitter surface and directed towards the receiver, thus generating electrical energy.

[0028] The coolant in thermionic fuel elements is used for waste heat discharge. The inventors of this application have discovered that the coolant outlet temperature is very high, reaching 843-873 K, which is still suitable as the hot-end input temperature for certain thermoelectric conversion elements (such as free-piston Stirling generators and lead telluride (PbTe) thermoelectric generators). Combining thermionic reactor with other thermoelectric conversion technologies, enabling the reactor to simultaneously employ thermionic conversion and other thermoelectric conversions, can significantly improve the thermoelectric conversion efficiency of the reactor power source.

[0029] Based on this, embodiments of the present invention provide a novel nuclear power source structure.

[0030] See Figures 1 to 3 The nuclear power source of this invention includes a reactor core 10. The reactor core 10 provides heat. The reactor core 10 includes multiple thermionic fuel elements 11, each with a coolant channel for coolant flow. The nuclear power source also includes a coolant circuit, multiple heat transfer pipes 40, and multiple sets of thermoelectric conversion modules. The coolant circuit receives coolant from the coolant channels and circulates the coolant back to the coolant channels. That is, the coolant flows from the coolant circuit through multiple thermionic fuel elements 11 and returns to the coolant circuit. The evaporation section of each heat transfer pipe 40 is thermally connected to the coolant circuit to conduct heat from the coolant in the coolant circuit to the condensation section of the heat transfer pipe 40. Each set of thermoelectric conversion modules is thermally connected to the condensation section of one heat transfer pipe 40 to convert the heat transferred by the heat transfer pipe 40 into electrical energy.

[0031] In this embodiment, the heat from the thermionic fuel element 11 is transferred to the reactor core 10 via a coolant circuit. Heat exchange is performed between the heat transfer tube 40 and the coolant circuit. The heat conducted by the heat transfer tube 40 is then converted into electrical energy using a thermoelectric conversion module. This allows the reactor to simultaneously employ thermionic conversion and other thermoelectric conversions, which can significantly improve the thermoelectric conversion efficiency of the reactor power supply.

[0032] This embodiment utilizes a coolant loop to remove heat from the thermionic fuel element 11 to the reactor core 10. Although the efficiency of heat extraction via the coolant loop is lower than that via heat pipes, the coolant loop significantly reduces the difficulty of extracting heat from the reactor core 10. Furthermore, using the coolant loop to extract heat allows for a non-rigid connection between the thermoelectric conversion module and the thermionic fuel element 11, providing vibration damping and preventing damage to the structurally delicate thermionic fuel element 11 caused by vibrations occurring at the thermoelectric conversion module. This embodiment further utilizes heat pipes to conduct heat from the coolant to the thermoelectric conversion module, maximizing heat transfer efficiency.

[0033] Furthermore, since this embodiment of the application includes multiple heat transfer pipes 40 and multiple sets of thermoelectric conversion modules, each set of thermoelectric conversion modules is thermally connected to one heat transfer pipe 40, and each heat transfer pipe 40 is thermally connected to the coolant circuit, the nuclear power source includes multiple repetitive components formed by one heat transfer pipe 40 and one set of thermoelectric conversion modules, and these repetitive components are independent of each other. This configuration provides redundancy to the nuclear power source; even if one or several repetitive components fail, the entire nuclear power source can still operate, giving the system excellent robustness. Moreover, during the research and development testing process, only the design and testing of a single repetitive component needs to be performed, reducing research and development costs, difficulty, and time, as well as testing costs, difficulty, and time.

[0034] In some embodiments, each thermoelectric conversion module includes a plurality of thermoelectric conversion elements 80, each thermoelectric conversion element 80 having an annular structure, wherein each thermoelectric conversion element 80 is sleeved on the condensing section of a heat transfer pipe 40, and the thermoelectric conversion element 80 is thermally connected to the condensing section.

[0035] The thermoelectric conversion element 80 is mounted on the condensation section of the heat transfer pipe 40, which can increase the connection strength and heat conduction area between the thermoelectric conversion element 80 and the heat transfer pipe 40, and is conducive to the thermoelectric conversion element 80 working stably and efficiently for a longer period of time.

[0036] In some embodiments, the first thermoelectric conversion element 80 is a thermoelectric power generation element, with its hot end and cold end located radially inside and radially outside the annular structure, respectively. The hot end of the thermoelectric power generation element is thermally connected to the condensation section.

[0037] In some embodiments, see Figure 4The nuclear power source also includes multiple heat pipes 50 for heat dissipation, corresponding one-to-one with multiple heat pipes 40. Each thermoelectric conversion module is also thermally connected to the evaporation section of a heat pipe 50. In this embodiment, the heat pipes 40 and 50 are thermally connected to the hot and cold ends of each thermoelectric conversion module, respectively. The heat pipes 40 can be referred to as primary heat pipes, and the heat pipes 50 can be referred to as secondary heat pipes.

[0038] In some embodiments, see Figure 5 and Figure 6 The heat pipe 50 includes a body section 51 and an annular connector section 52. The outer diameter of the annular connector section 52 is larger than the outer diameter of the body section 51. The body section 51 defines a body cavity. The annular connector section 52 is axially connected to one end of one side of the body section 51, and the annular connector section 52 defines an annular connector cavity communicating with the body cavity. In such an embodiment, the heat pipe 50 is an irregularly shaped heat pipe.

[0039] The heat pipe 50 also includes a working medium and a wick. The working medium flows between the body cavity and the annular connector cavity. The wick is disposed within the body cavity and the annular connector cavity to provide capillary pressure for the flow of the working medium. The annular connector section 52 of the heat pipe 50 corresponds to the evaporation section, and the body section 51 corresponds to the condensation section. Under the capillary force of the wick, the liquid working medium in the body section 51 absorbs heat and evaporates in the evaporation section. The evaporated working medium moves to the condensation section, releases heat and condenses, thus completing the heat transfer. The condensed working medium in the condensation section can return to the evaporation section, thus completing the circulation of the working medium. In this embodiment, the working medium in the heat pipe can be potassium, and the material of the heat pipe shell and the wick can be 316L stainless steel.

[0040] The liquid suction core can be made of metal wire mesh and can be placed inside the annular connector cavity and the body cavity and fit against the inner wall of the cavity.

[0041] See Figure 6 The condensing section of the heat transfer heat pipe 40 extends radially inside the annular joint section 52. An annular gap exists between the heat transfer heat pipe 40 and the annular joint section 52, and the thermoelectric conversion module is disposed within this annular gap. In this embodiment, since the heat transfer heat pipe 40 and the heat dissipation heat pipe 50 are used simultaneously to transfer heat to the hot and cold ends of the thermoelectric power generation element, the heat conduction efficiency is high, which helps to increase the temperature difference between the hot and cold ends of the thermoelectric power generation element, thereby improving the power generation efficiency of the thermoelectric power generation element. Because multiple thermoelectric power generation elements in each thermoelectric conversion module are sequentially sleeved along the axial direction on the evaporation section of the heat transfer heat pipe 40, and the heat dissipation heat pipe 50 is sleeved radially outside the multiple thermoelectric power generation elements in each thermoelectric conversion module, it helps to achieve uniformity of the hot and cold end temperatures of each thermoelectric power generation element in each thermoelectric conversion module.

[0042] The inventors of this application have also discovered that the overall power generation efficiency of the nuclear power supply in the embodiments of this application decreases significantly after a period of use. The inventors found that when the heat dissipation heat pipe 50 is connected to the heat transfer heat pipe 40 via a thermoelectric power generation element, the cold and hot ends of the thermoelectric power generation element are thermally connected to the heat dissipation heat pipe 50 and the heat transfer heat pipe 40 respectively, without any other mechanical connection structure to fix the heat dissipation heat pipe 50 and the heat transfer heat pipe 40 together. Because the thermoelectric power generation material is brittle and cannot withstand large shear stresses, after a period of use, the thermoelectric power generation element may break due to the shear stress from the two heat pipes, resulting in a significant decrease in the overall power generation efficiency of the thermoelectric power generation module.

[0043] Therefore, in view of the above situation, in some embodiments, the inventors of this application have specially set up a support frame 60 to mechanically connect the heat dissipation heat pipe 50 and the heat transfer heat pipe 40 to provide support for the heat dissipation heat pipe 50, thereby ensuring the relative position stability of the heat dissipation heat pipe 50 and the heat transfer heat pipe 40 and avoiding the thermal power generation element from breaking under stress.

[0044] In this embodiment, the support frame 60 serves as a mechanical connection between the two heat pipes, eliminating the need for a thermoelectric generator to mechanically connect the two heat pipes. Consequently, the thermoelectric generator does not need to bear the shear stress caused by connecting the two heat pipes, thus ensuring the service life of the thermoelectric generator.

[0045] In some embodiments, the support frame 60 includes two hollowed-out discs and multiple support rods 63. The two hollowed-out discs are a first hollowed-out disc 61 and a second hollowed-out disc 62. The first hollowed-out disc 61 is connected to the body section 51 of the heat dissipation heat pipe 50, and the second hollowed-out disc 62 is connected to the heat transfer heat pipe 40. Each support rod 63 has two hollowed-out discs connected to its two ends. In this embodiment, since the support frame 60 is a hollowed-out structure, its heat transfer cross-section is small and its heat transfer distance is long. Therefore, the heat transfer resistance from the heat transfer heat pipe 40 through the support frame 60 to the heat dissipation heat pipe 50 is large, much greater than the heat transfer resistance from the heat transfer heat pipe 40 through the thermoelectric generator to the heat dissipation heat pipe 50. Therefore, this support frame 60 can reduce heat leakage from the heat transfer heat pipe 40 to the heat dissipation heat pipe 50 and improve the overall conversion efficiency of the thermoelectric generator.

[0046] In some embodiments, the perforated disk includes an inner ring 611, an outer ring 612, and a plurality of connecting rods 613 connecting the inner ring 611 and the outer ring 612. The inner ring 611 is connected to the body segment 51 of the heat transfer heat pipe 40 or the heat dissipation heat pipe 50. The outer ring 612 is located radially outside the inner ring 611, and the inner diameter of the outer ring 612 is larger than the outer diameter of the annular connector segment 52. Each connecting rod 613 connects to the outer rings 612 of two perforated disks at both ends. In such an embodiment, the thermal resistance of heat transfer from the heat transfer heat pipe 40 through the support frame 60 to the heat dissipation heat pipe 50 can be further increased, thereby further reducing heat leakage from the heat transfer heat pipe 40 to the heat dissipation heat pipe 50.

[0047] In some embodiments, the coolant circuit includes an annular conduit 30. The annular conduit 30 defines an annular cavity. See also Figure 7 The evaporation section of each heat transfer tube 40 is inserted into the annular cavity of the annular pipe 30, absorbing heat from the working fluid inside the annular pipe 30. The end of the evaporation section of the heat transfer tube 40 enters the annular cavity but does not contact the outer shell of the annular pipe 30. In other words, there is a gap between the end of the evaporation section and the cavity wall of the annular cavity to prevent significant stratification of the coolant in the annular cavity, which would affect the uniformity of the coolant temperature.

[0048] In some embodiments, to reduce heat transfer, a gap exists between the end face of the evaporation section of the heat pipe 40 and the end face of the annular joint section 52 of the heat dissipation heat pipe 50 facing each other. The nuclear power source also includes an insulating heat insulation component 90, disposed radially inside the annular joint section 52 of the heat dissipation heat pipe 50, with the end face of the evaporation section of the heat transfer heat pipe 40 connected to the insulating heat insulation component 90. The insulating heat insulation component 90 is made of insulating heat insulation material, and thus serves both as insulation and heat insulation, and as an axial limiting function for each thermoelectric conversion module.

[0049] In some embodiments, the nuclear power source further includes: a plurality of heat sinks 70, each heat sink 70 being welded to a heat pipe 50 for dissipating heat from the heat pipe 50. Heat can be discharged into space through the heat sinks 70. The heat sinks 70 can increase the heat dissipation area of ​​the heat pipe 50, allowing the working medium to dissipate more heat when flowing through the heat pipe 50, thereby achieving the cooling of the coolant.

[0050] The heat sink 70 is spaced apart from the support frame 60, and the support frame 60 is spaced apart from the annular pipe 30 to reduce heat transfer.

[0051] The heat sink 70 can be made of aluminum. The overall shape of the annular pipe 30 is circular. The axis along the length of the annular pipe 30 (the axis being the center line of the circle) is tangent to the plane where the heat sink 70 is located. The axis along the length of the annular pipe 30 can be the line connecting the centers of all the cross-sections of the annular pipe 30. This arrangement can improve the overall heat dissipation effect.

[0052] In some embodiments, the plane containing the axis of the annular pipe 30 along its length makes an angle with the axis of the body section 51. Multiple heat transfer pipes 40 are installed after the annular pipe 30, and the overall structure of the multiple heat transfer pipes 40 is a truncated cone, with the axis of the truncated cone being the same as the axis of the annular pipe 30. The heat sink 70 has an overall trapezoidal structure, with the width of the heat sink 70 near the joint section being smaller than the width of the other side. This allows the heat sink 70 on one side of the body section 51 to have a larger heat dissipation area, which is beneficial for heat dissipation. Such a heat dissipation structure is particularly suitable for use in space nuclear power plants.

[0053] In some embodiments, the coolant circuit further includes a coolant inlet line 201 and a coolant outlet line 202. The coolant inlet line 201 is connected to the annular line 30 and is used to receive coolant from the coolant passage. The coolant outlet line 202 is connected to the annular line 30 and is used to return coolant from the annular line 30 to the coolant passage.

[0054] The reactor core 10 also includes a first flow collector 12 and a second flow collector 13.

[0055] The two ends of the coolant inflow pipe 201 are connected to the annular pipe 30 and the first manifold 12, respectively, for the return of coolant in the annular pipe 30 to the first manifold 12. The two ends of the coolant outflow pipe 202 are connected to the annular pipe 30 and the second manifold 13, respectively, for the coolant to flow out of the second manifold 13 and into the annular pipe 30. The coolant flows from the first manifold 12 through each thermionic fuel element 11 and then into the second manifold 13. The annular pipe 30, the first manifold 12, the second manifold 13, the coolant inflow pipe 201, the coolant outflow pipe 202, and the coolant channels formed inside each thermionic fuel element 11 together form a closed loop.

[0056] In some embodiments, a volume compensator 22 may be provided in the coolant inlet pipe 201 or the coolant outlet pipe 202 for volume compensation of the coolant flowing in the circuit. In some embodiments, a pump 21 may also be provided in the coolant inlet pipe 201 or the coolant outlet pipe 202 for driving the flow of coolant in the circuit. For example, the pump 21 may be provided in the coolant inlet pipe 201, and the volume compensator 22 may be provided in the coolant outlet pipe 202. In the embodiments of this application, the coolant may be a sodium-potassium alloy working fluid, and the pump 21 may be an electromagnetic pump 21. The first collecting chamber 12 and the second collecting chamber 13 may be located at the top and bottom of the core 10, respectively.

[0057] The heat transfer heat pipe 40 has a stainless steel shell and uses potassium as the working fluid. The thermoelectric element uses lead telluride type thermoelectric material (PbTe / TAGS). The heat dissipation heat pipe 50 has a titanium alloy shell and uses water as the working fluid.

[0058] See Figure 3 In some embodiments, the reactor core 10 includes a solid moderator 18, fuel elements, a control drum 16, and a radial reflector layer 17.

[0059] The solid moderator 18 forms multiple channels, and multiple thermionic fuel elements 11 are respectively arranged in the corresponding channels of the solid moderator 18. A radial reflector layer 17 is formed on the radially outer side of the solid moderator 18. The radial reflector layer 17 is used to prevent radiation and heat generated by the fuel elements from leaking radially along the core 10. A control drum 16 is disposed in the radial reflector layer 17 and is used to adjust the nuclear fission reaction rate of the fuel elements to achieve reactor power control.

[0060] In some embodiments, the nuclear power source further includes a plurality of control drum drive mechanisms 15, which are disposed on the shield 14 and drivenly connected to the control drum 16 for driving the rotation of the control drum 16.

[0061] exist Figure 3 In the illustrated embodiment, the thermionic reactor core 10 is exemplified by Topaz-II. The moderator material can be zirconium hydride. The radial reflector layer 17 can be made of beryllium. The main body material of the control drum 16 can be beryllium, and the neutron absorber material of the control drum 16 can be boron carbide. The core 10 is equipped with 37 thermionic fuel elements 11 and 12 control drums 16.

[0062] The nuclear power source in this embodiment can be located in space to supply power to satellites and other equipment; such a nuclear power source can be called a space nuclear power source. In this nuclear power source, the specific core structure 10, the number of thermionic fuel elements 11, the number of thermoelectric power generation systems, etc., can be designed according to actual parameter requirements.

[0063] In some embodiments, the nuclear power source may further include a shield 14 disposed directly above the reactor core 10 for shielding against radioactive radiation from the reactor core 10.

[0064] The annular pipe 30 is located directly above the shield 14, and the heat transfer pipe 40 extends upward at an angle from the annular pipe 30 away from the shield. The first collector cavity 12 and the shield 14 are both coaxial with the core 10. The radius of the shield 14 is larger than the radius of the core 10 to prevent the radiation from the core 10 from directly penetrating the upper components along the shield 14.

[0065] The shield 14 is coaxially arranged with the reactor core 10. The shield 14 is generally truncated cone-shaped, with the diameter of the end of the shield 14 away from the reactor core 10 being larger than the diameter of the end facing the reactor core 10. The end face of the shield away from the reactor core 10 includes a circular end face and an annular inclined surface formed around the circular end face. The circular end face is further away from the reactor core 10 than the annular inclined surface to reduce the overall weight of the shield 14.

[0066] The first collector chamber 12 is located below the shield 14. The coolant inlet pipe 201 extends upwards from the first collector chamber 12 along the peripheral wall of the shield 14, then extends vertically upwards a predetermined distance before connecting to the annular pipe 30. The coolant outlet pipe 202 extends vertically upwards from the second collector chamber 13 along the core 10 to the shield 14, continues upwards along the peripheral wall of the shield 14, then extends vertically upwards a predetermined distance before connecting to the annular pipe 30. The coolant inlet pipe 201 and the coolant outlet pipe 202 are radially opposite each other along the core 10. This arrangement minimizes radiation received by the coolant pipes. The coolant inlet pipe 201 and the coolant outlet pipe 202 are connected to the radial ends of the annular pipe 30 to ensure uniform coolant temperature within the annular pipe 30.

[0067] The working principle of a nuclear power source is explained below using Topaz-II thermionic reactor core 10 as an example.

[0068] After the nuclear power source is successfully launched, under the action of the control drum drive mechanism 15, the absorber of the control drum 16 is slowly turned to a position away from the active area of ​​the reactor core 10 until the entire system reaches the rated power stable operation state.

[0069] When core 10 is running, the fuel generates 115 kWt of thermal power, with an emitter temperature of approximately 1800 K. The 37 thermionic fuel elements 11 generate approximately 5 kWe of electrical power, corresponding to a conversion efficiency of approximately 4.3%. The sodium-potassium loop carries the remaining approximately 110 kWt of thermal power outside the reactor core, transferring it through annular pipe 30 to numerous heat transfer pipes 40. The heat is then transferred to lead telluride thermoelectric generators located in the condensation section of the heat transfer pipes 40 via spontaneous phase change and circulation of the working fluid. The thermoelectric generators have a hot-end temperature of approximately 866 K and a cold-end temperature of approximately 547 K, with a thermoelectric conversion efficiency of approximately 5%, generating approximately 5.5 kWe of electrical power. Combined with the 5 kWe of electrical power generated by the thermionic fuel elements 11, the total electrical power of the nuclear power system reaches approximately 10.5 kWe, corresponding to a total system thermoelectric conversion efficiency of approximately 9.1%. The waste heat from the thermoelectric generator is carried out by the heat pipe 50 and discharged into space through the heat sink 70.

[0070] As can be seen, the embodiments of this application, based on the existing thermionic reactor, introduce a thermoelectric power generation system by setting up a loop and heat pipe, which greatly improves the thermoelectric conversion efficiency of the system from 4.3% to about 9.1%.

[0071] Regarding core 10, the embodiments of this application do not increase the operating temperature of the thermionic reactor. Therefore, core 10 can fully utilize the relevant technologies of existing thermionic reactors without increasing the development difficulty. The embodiments of this application simultaneously employ two thermoelectric conversion methods, enabling the nuclear power source to significantly improve thermoelectric conversion efficiency without significantly increasing the development difficulty.

[0072] In this embodiment, both the thermo-ion fuel element 11 and the thermoelectric generator element are static conversion methods, meaning the entire system is still a static thermoelectric conversion without introducing dynamic components (such as Stirling generators), which maintains good system reliability and is beneficial for spacecraft attitude control.

[0073] Regarding the embodiments of the present invention, it should also be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0074] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A nuclear power source, comprising a reactor core, characterized in that, The reactor core includes multiple thermionic fuel elements, each of which has a coolant channel inside for coolant flow. The nuclear power source also includes: A coolant circuit for receiving coolant from the coolant passage and circulating the coolant back to the coolant passage; Multiple heat transfer pipes, each heat transfer pipe having an evaporation section thermally connected to the coolant circuit; and Multiple sets of thermoelectric conversion modules, each set of thermoelectric conversion modules is thermally connected to the condensation section of one of the heat transfer heat pipes, so as to convert the heat transferred by the heat transfer heat pipes into electrical energy; Each thermoelectric conversion module includes multiple thermoelectric conversion elements, each having a ring structure. Each thermoelectric conversion element is fitted onto the condensation section of a heat transfer tube, and the thermoelectric conversion element is thermally connected to the condensation section. The thermoelectric conversion element is a thermoelectric power generation element, and the hot end and cold end of the thermoelectric power generation element are located on the radial inner side and radial outer side of the annular structure, respectively. The hot end of the thermoelectric generator is thermally connected to the condensation section. The nuclear power source also includes: Multiple heat dissipation pipes correspond one-to-one with the multiple heat transfer pipes, and each group of thermoelectric conversion modules is also thermally connected to the evaporation section of one of the heat dissipation pipes. The heat pipe includes: Body segment, the body segment defining a body cavity; and An annular connector segment is axially connected to one end of one side of the body segment, and the annular connector segment defines an annular connector cavity that communicates with the body cavity. The condensation section of the heat transfer tube extends into the radial inner side of the annular joint section, and there is an annular gap between the heat transfer tube and the annular joint section. The thermoelectric conversion module is disposed within the annular gap between the heat transfer tube and the annular joint section.

2. The nuclear power source according to claim 1, characterized in that, Also includes: A support frame is used to mechanically connect the heat dissipation heat pipe and the heat transfer heat pipe to provide support for the heat dissipation heat pipe.

3. The nuclear power source according to claim 2, characterized in that, The support frame includes: Two hollowed-out discs are respectively connected to the body section of the heat dissipation heat pipe and the heat transfer heat pipe; Multiple support rods, each of which is connected to two hollowed-out discs at both ends.

4. The nuclear power source according to claim 3, characterized in that, The hollowed-out disk includes an inner ring, an outer ring, and multiple connecting rods connecting the inner ring and the outer ring. The inner ring is connected to the body section of the heat transfer pipe or the heat dissipation pipe. The outer ring is located radially outside the inner ring, and the inner diameter of the outer ring is larger than the outer diameter of the annular connector section. Each of the connecting rods is connected at both ends to the outer ring of the two hollowed-out discs.

5. The nuclear power source according to claim 1, characterized in that, The coolant circuit includes: A ring-shaped pipeline, which defines a ring-shaped cavity; A coolant inflow pipe, connected to the annular pipe, is used to receive coolant from the coolant channel; and The coolant outlet pipe is connected to the annular pipe to allow coolant from the annular pipe to return to the coolant channel; The evaporation section of each heat transfer tube is inserted into the annular cavity of the annular pipe.

6. The nuclear power source according to claim 1, characterized in that, Also includes: Multiple heat sinks, each of which is welded to a heat pipe for dissipating heat from the heat pipe.

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