CN116825414A - Nuclear power supply - Google Patents

Abstract

The embodiment of the application provides a nuclear power source, which comprises: a core including a plurality of thermionic fuel elements, each of the thermionic fuel elements having a first coolant channel formed therein for flowing a first coolant; a first manifold and a second manifold, the first coolant flowing from the first manifold through the thermionic fuel element and into the second manifold; at least one heat exchanger, each heat exchanger having a first coolant flow passage and a second coolant flow passage capable of exchanging heat; a first coolant circuit for receiving the first coolant from the second manifold and returning the first coolant to the first manifold after flowing through the first coolant flow passage; at least one second coolant circuit for circulating a second coolant, the second coolant in each second coolant circuit being capable of flowing through one of the second coolant flow channels; and at least one thermoelectric conversion element, each for converting heat of one of the second coolant loops into electrical energy.

Description

Nuclear power supply

Technical Field

The embodiment of the application relates to the technical field of nuclear reactors, in particular to a nuclear power source.

Background

The nuclear power supply can be applied to the aerospace field, and can generate heat energy through a reactor core of a nuclear reactor, convert the heat energy into electric energy, realize the energy supply for a spacecraft, and enable the spacecraft to get rid of the energy dependence on the sun.

In a nuclear power source, only one type of thermoelectric conversion element is generally used to convert heat of a reactor core into electric energy, and the output power of the power source is low.

Disclosure of Invention

Aiming at the technical problems, the embodiment of the application provides a nuclear power supply.

The nuclear power source of the embodiment of the application comprises: a core for providing heat, the core comprising a plurality of thermionic fuel elements, each thermionic fuel element having a first coolant channel formed therein for flowing a first coolant; a first manifold and a second manifold, the first coolant flowing from the first manifold through the plurality of thermionic fuel elements and then into the second manifold; at least one heat exchanger, each heat exchanger having a first coolant flow passage and a second coolant flow passage capable of exchanging heat; a first coolant circuit for receiving the first coolant from the second manifold and returning the first coolant to the first manifold after flowing through the first coolant flow passage of the at least one heat exchanger; at least one second coolant circuit for circulating a second coolant, the second coolant in each second coolant circuit being capable of flowing through a second coolant flow passage of one of the heat exchangers to exchange heat with the first coolant; and at least one thermoelectric conversion element, each thermoelectric conversion element being connected to one of the second coolant loops for converting heat of one of the second coolant loops into electrical energy.

According to the embodiment of the application, the heat of the thermoionic fuel element is led out of the reactor by the first coolant loop, the second coolant loop exchanges heat with the first coolant loop, and the heat of the second coolant loop is converted into electric energy by the thermoelectric conversion element, so that the thermoionic conversion and other thermoelectric conversion are adopted by the reactor at the same time, and the thermoelectric conversion efficiency of a reactor power supply can be greatly improved.

Drawings

Other objects and advantages of the present application will become apparent from the following description of the application with reference to the accompanying drawings, which provide a thorough understanding of the present application.

FIG. 1 is a schematic diagram of a nuclear power source according to one embodiment of the application;

FIG. 2 is a schematic diagram of a nuclear power source according to one embodiment of the application;

FIG. 3 is an enlarged schematic view of a portion of the nuclear power source of FIG. 2;

FIG. 4 is an enlarged schematic view of a portion of the nuclear power source of FIG. 3;

FIG. 5 is a partial elevation view of the nuclear power source of FIG. 2;

FIG. 6 illustrates a partial schematic diagram of a nuclear power source in another embodiment;

FIG. 7 illustrates an enlarged partial schematic view of the nuclear power source of FIG. 6;

FIG. 8 is a schematic cross-sectional view of a core of a nuclear power source according to an embodiment of the application;

fig. 9 is a schematic view of a nuclear power source disposed in a moon pool according to an embodiment of the present application.

It should be noted that the drawings are not necessarily to scale, but are merely shown in a schematic manner that does not affect the reader's understanding.

Reference numerals illustrate:

10. a core; 11. a thermionic fuel element; 12. a first manifold; 13. a second manifold; 14. a shield; 141. a first shield; 142. a second shield; 15. a control drum driving mechanism; 16. a control drum; 17. a radial reflective layer; 18. a solid moderator;

20. a first coolant circuit; 21. a first pump; 22. a first volume compensator; 201. a coolant inflow line; 202. a coolant outflow line; 203. a first branch; 204. a second branch;

30. a heat exchanger;

40. a second coolant circuit; 41. a second pump; 42. a second volume compensator; 401. a flexible bellows segment;

50. a thermoelectric conversion element;

60. a third coolant circuit; 61. a third pump; 62. a third volume compensator; 601. a flexible bellows segment;

70. a heat sink;

800. lunar soil; 810. a moon pool; 820. the moon surface.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present application. It will be apparent that the described embodiments are one embodiment, but not all embodiments, of the present application. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present application fall within the protection scope of the present application.

It is to be noted that unless otherwise defined, technical or scientific terms used herein should be taken in a general sense as understood by one of ordinary skill in the art to which the present application belongs.

In the description of the embodiments of the present application, the meaning of "plurality" is at least two, for example, two, three, etc., unless explicitly defined otherwise.

The structure of the thermionic fuel element is very precise. The thermal ion fuel element is sequentially from inside to outside: the device comprises a fuel, an emitter, a power generation gap, a receiving electrode, an electric insulator, a helium cavity, a stainless steel inner pipe wall, a first coolant and a stainless steel outer pipe wall. The first coolant is typically a sodium potassium alloy and, in operation, the emitter temperature is as high as about 1800K, well above the receiver temperature, and the emitter surface releases electrons and directs them to the receiver, thereby generating electrical energy.

The first coolant in the thermoionic fuel element is used for waste heat discharge. The inventors of the present application have found that the outlet temperature of the first coolant is very high, capable of achieving 843-873K, which is still suitable as the hot side input temperature for some thermoelectric conversion elements, such as free piston stirling generators. If the thermionic reactor is combined with other thermoelectric conversion technologies, the thermionic conversion and other thermoelectric conversion are adopted by the reactor at the same time, so that the thermoelectric conversion efficiency of the reactor power supply can be greatly improved.

In the related art, the thermoionic thermoelectric conversion element is wrapped in the reactor core by a linear heat pipe, the other end of the linear heat pipe extends out of the reactor core to be directly connected with the heat exchange device, and the Stirling generator is directly connected with the heat exchange device. In such a related art, although the linear heat pipe has good thermal conductivity, since the linear heat pipe has a rigid structure, vibration is generated when the stirling generator is operated, and the vibration is transmitted to the thermionic thermoelectric conversion element through the linear heat pipe. The structure of the thermoionic thermoelectric conversion element is similar to that of the thermoionic fuel element, the structure is very precise, vibration conducted by the Stirling generator can lead to short service life of the thermoionic thermoelectric conversion element, and the reliability of a power supply is greatly reduced.

Aiming at the technical problem, the embodiment of the application provides a nuclear power source with a novel structure.

Referring to fig. 1 and 2, a nuclear power source provided in an embodiment of the present application includes: the reactor comprises a core 10, a first manifold 12 and a second manifold 13, at least one heat exchanger 30, a first coolant loop 20, at least one second coolant loop 40, and at least one thermoelectric conversion element 50.

The core 10 is used to provide heat. The core 10 includes a plurality of thermoionic fuel elements 11, each of which thermoionic fuel elements 11 internally forms a first coolant channel for the flow of a first coolant. The first coolant flows from the first manifold 12 through each of the thermionic fuel elements 11 and then into the second manifold 13. The first manifold 12 and the second manifold 13 may be located at the top and bottom of the core 10, respectively.

Each heat exchanger 30 has a first coolant flow passage and a second coolant flow passage capable of exchanging heat. The first coolant loop 20 is configured to receive the first coolant from the second manifold 13 and return the first coolant to the first manifold 12 after flowing through the first coolant flow path of the heat exchanger 30. The second coolant circuit 40 is for circulating a second coolant. The second coolant in each of the second coolant loops 40 is capable of flowing through the second coolant flow channels of one of the heat exchangers 30 to exchange heat with the first coolant. Each thermoelectric conversion element 50 is connected to one of the second coolant loops 40 for converting heat of one of the second coolant loops 40 into electrical energy.

In the embodiment of the application, the heat of the thermoionic fuel element 11 is led out of the reactor by the first coolant loop 20, the second coolant loop 40 exchanges heat with the first coolant loop 20, and the thermoelectric conversion element 50 converts the heat of the second coolant loop 40 into electric energy, so that the thermoionic conversion and other thermoelectric conversion are adopted by the reactor at the same time, and the thermoelectric conversion efficiency of the reactor power supply can be greatly improved.

In the embodiment of the application, the heat of the thermoionic fuel element 11 is led out of the reactor by the first coolant loop 20, and meanwhile, the thermoelectric conversion element 50 is connected with the second coolant loop 40, so that the thermoelectric conversion element 50 and the thermoionic fuel element 11 are not rigidly connected by the linear heat pipe and the heat exchanger 30, and when the thermoelectric conversion element 50 vibrates, the heat is not basically transferred to the thermoionic fuel element 11, thereby avoiding the adverse effect on the thermoionic fuel element 11 due to the vibration of the thermoelectric conversion element 50.

Referring to fig. 3 and 4, in some embodiments, the number of heat exchangers 30, second coolant loops 40, and thermoelectric conversion elements 50 is two, respectively. The first coolant circuit 20 further includes: a coolant inflow line 201, a coolant outflow line 202, and a first branch 203 and a second branch 204 connected in parallel. The coolant inflow line 201 communicates with the first manifold 12 for returning the first coolant to the first manifold 12. The coolant outflow line 202 communicates with the second manifold 13 for the flow of the second coolant out of the second manifold 13. The two heat exchangers 30 are disposed on the first branch 203 and the second branch 204, respectively. Wherein the coolant inflow line 201 and the coolant outflow line 202 communicate through a first branch 203 and a second branch 204 connected in parallel. In such an embodiment, the nuclear power source comprises two sets of second coolant loops 40, thermoelectric conversion elements 50 and heat exchangers 30 which are independent of each other, so that the nuclear power source has redundancy, and the system can still continue to operate and output certain electric power when a single device fails, thereby being beneficial to the safety of the lunar surface base.

In some embodiments, the first coolant loop 20, the two heat exchangers 30, the two second coolant loops 40, and the two thermoelectric conversion elements 50 are each symmetrically arranged with respect to a vertical bisecting plane of the core 10. The vertical bisecting plane may be understood as a vertical plane passing through the axis of the core 10, with respect to which the portions of the core 10 located on either side of the vertical bisecting plane are symmetrical. The first coolant loop 20, the two heat exchangers 30, and the two second coolant loops 40 are each symmetrically disposed with respect to the vertical bisector of the core 10, meaning that the first leg 203 and the second leg 204 are also symmetrically disposed with respect to the vertical bisector of the core 10. This arrangement is advantageous in that the paths through which the first coolant of the two branches and the second coolant of the two circuits circulate are completely symmetrical, and thus, the second coolant of the two second coolant circuits 40 is advantageously maintained at the same flow rate and temperature, thereby, it is advantageous in that the two thermoelectric conversion elements 50 are ensured to be in substantially the same working environment, and the power output of the nuclear power source is ensured to be stable.

Referring to fig. 5, in some embodiments, the axes of the coolant inflow conduit 201 and the coolant outflow conduit 202 are both located in a vertical bisecting plane. In such an embodiment, it is advantageous to achieve a symmetrical arrangement of the above-mentioned components and pipes, and thus a complete symmetry of the nuclear power source as a whole.

In some embodiments, the first branch 203 and the second branch 204 are located on two sides of the vertical plane, so as to further facilitate the symmetrical arrangement of the above components and the pipes.

In the embodiment of the present application, the thermoelectric conversion element 50 is a stirling generator. In the embodiment of the application, the heat of the thermoionic fuel element 11 is led out of the reactor by the first coolant loop 20, and the Stirling generator is connected with the second coolant loop 40, so that the Stirling generator and the thermoionic fuel element 11 are not rigidly connected any more, and the heat is not basically transferred to the thermoionic fuel element 11 when the Stirling generator vibrates, thereby avoiding the adverse effect on the thermoionic fuel element 11 caused by the vibration of the Stirling generator. In particular, since the first manifold 12 and the second manifold 13 are also provided, the influence of the vibration of the Stirling generator on the thermionic fuel element 11 can be further reduced.

Further, the thermoelectric conversion element 50 may be an opposed Stirling generator to further reduce vibration. A set of two opposed stirling generators are disposed in each of the second coolant loops 40. The Stirling generator is located as far from the reactor as possible to reduce the dose to which it is exposed.

Referring to fig. 6 and 7, in some embodiments, the second coolant loop 40 includes a flexible bellows segment 401, the flexible bellows segment 401 being configured to absorb vibrations from the stirling generator and isolate the effects of the stirling generator vibrations on other components of the system.

The second coolant loop 40 may include two flexible bellows sections 401, with the two flexible bellows sections 401 each being in close proximity to the Stirling generator. That is, the two flexible bellows sections 401 are each proximate to the location where the second coolant circuit 40 is connected to the Stirling generator.

In some embodiments, a vibration damper may be disposed around the Stirling generator, and the Stirling generator may be damped by the vibration damper.

In some embodiments, the core power supply further comprises: at least one third coolant loop 60 and at least one set of radiators 70.

The third coolant circuit 60 is for circulating a third coolant for radiating heat from the thermoelectric conversion element 50. Each group of radiators 70 is thermally coupled with one of the third coolant loops 60 for radiating heat from the third coolant of the third coolant loop 60. The number of third coolant loops 60 is the same as the number of thermoelectric conversion elements 50. When the number of the thermoelectric conversion elements 50 is two, the number of the third coolant loops 60 is also two, and the number of the radiator 70 is two.

In some embodiments, the third coolant loop 60 may also include a flexible bellows segment 601, the flexible bellows segment 601 being configured to absorb vibrations from the Stirling generator, isolating the Stirling generator from vibrations affecting other components of the system. The third coolant loop 60 may include two flexible bellows sections 601, with the two flexible bellows sections 601 each being in close proximity to the Stirling generator. That is, the two flexible bellows sections 601 are each proximate to the location where the third coolant loop 60 is connected to the Stirling generator. Therefore, four pipelines connected with four coolant interfaces of the Stirling generator are provided with flexible corrugated pipe sections 601, so that the influence of vibration of the Stirling generator on other parts of the system can be further reduced.

In some embodiments, a volume compensator may be further disposed on each circuit for volume compensation of the coolant flowing in each circuit. Specifically, the first coolant circuit 20 is provided with a first volume compensator 22, the second coolant circuit 40 is provided with a second volume compensator 42, and the third coolant circuit 60 is provided with a third volume compensator 62.

In some embodiments, a pump may also be provided on each circuit for driving the flow of coolant in the circuit. Specifically, the first coolant circuit 20 is provided with a first pump 21, the second coolant circuit 40 is provided with a second pump 41, and the third coolant circuit 60 is provided with a third pump 61.

The first pump 21 is provided in the coolant inflow line 201, and the first volume compensator 22 is provided in the coolant outflow line 202. The second pump 41 and the second volume compensator 42 are arranged at the cooling medium outlet side and the cooling medium inlet side of the heat exchanger 30, respectively. The third pump 61 and the third volume compensator 62 are disposed on the cooling medium outlet side and the cooling medium inlet side of the thermoelectric conversion element 50, respectively.

In the embodiment of the application, the first coolant and the second coolant can be sodium-potassium working media, and the third coolant can be water. The first pump 21 and the second pump 41 may be electromagnetic pumps, and the third pump 61 may be a water pump.

Referring to fig. 2, each set of heat sinks 70 includes a plurality of heat dissipation heat pipes and fins for better heat dissipation performance. When the third coolant is water, the heat-dissipating heat pipe may be a water heat pipe (i.e., the working medium in the heat pipe is water).

As shown, the third coolant loop 60 may include a U-shaped tube with an opening facing the heat exchanger 30. Each heat dissipation heat pipe is thermally connected with the U-shaped pipeline. Each radiating fin can be welded to one radiating heat pipe and used for radiating heat of the radiating heat pipe. The radiating fin can increase the radiating area and improve the radiating effect. The heat-dissipating heat pipe may transfer heat in the coolant to the heat sink so that the heat is dissipated by the heat sink.

The U-shaped pipeline comprises a first horizontal section and a second horizontal section which are parallel to each other, and a vertical section which is connected with the first horizontal section and the second horizontal section, wherein one end of each heat dissipation heat pipe is in heat conduction connection with the first horizontal section or the second horizontal section, and the other end of each heat dissipation heat pipe extends along the axis of the reactor core 10 towards a direction far away from the reactor core 10. Through the arrangement mode, the heat dissipation heat pipe can be perpendicular to the gravity direction, so that the heat conduction efficiency of the heat pipe is better.

The U-shaped piping of the third coolant loop 60 and the radiator 70 lie in the same vertical plane, which is also the vertical bisecting plane of the reactor, which is perpendicular to the other vertical bisecting plane.

In some embodiments, two second coolant loops 40 extend in opposite directions from the two heat exchangers 30, respectively, and two third coolant loops 60 extend in opposite directions from the two thermoelectric conversion elements 50, respectively, so as to enable the two sets of radiators 70 to be as far away from the core 10 as possible; since the heat pipes and fins of the radiator 70 have axes parallel to the axis of the core 10, the radiation of the core 10 to the radiator 70 can be further reduced.

Referring to FIG. 8, in some embodiments, the core 10 includes a solid moderator 18, fuel elements, a control drum 16, and a radially reflective layer 17.

The solid moderator 18 forms a plurality of channels, and the plurality of thermionic fuel elements 11 are respectively disposed in the corresponding channels of the solid moderator 18. The moderator material may be zirconium hydride. The radial reflecting layer 17 is formed radially outward of the solid moderator 18. The radial reflecting layer 17 serves to prevent rays and heat generated from the fuel elements from leaking in the radial direction of the core 10. The radially reflecting layer 17 may be of beryllium. A control drum 16 is provided in the radially reflective layer 17 for adjusting the nuclear fission reaction rate of the fuel element to achieve control of the reactor power. The control drum 16 body material may be beryllium and the control drum 16 neutron absorbing material may be boron carbide.

In some embodiments, the nuclear power source further comprises a plurality of control drum drive mechanisms 15, the control drum drive mechanisms 15 being disposed on the shield 14 in driving connection with the control drum 16 for driving rotation of the control drum 16. In the embodiment shown in fig. 8, the core 10 is arranged with 37 thermionic fuel elements 11 and 12 control drums 16.

The nuclear power source in this embodiment may be disposed on the lunar surface, and may be referred to as a lunar nuclear power source, for supplying power to other devices on the lunar surface. The specific core 10 configuration, number of thermionic fuel elements 11, heat exchanger 30 configuration, stirling generator power rating, radiator 70 area, etc. may be designed according to actual lunar surface stack parameter requirements.

The thermionic reactor core 10 is disposed in a pre-dug moon pool 810. In some embodiments, the core power supply may further include: and a shield 14 disposed directly above the core 10 for shielding radioactive radiation from the core 10. The heat exchanger 30 is disposed directly above the shield 14.

The shield 14 includes a first shield 141 located at an upper layer and a second shield 142 located at a lower layer. The first and second shields 141, 142 are both coaxial with the core 10. The radius of the first shield 141 is greater than the radius of the second shield 142 to avoid the core 10 rays from penetrating directly to the upper components along the gap between the shield 14 and the lunar soil 800.

The first manifold 12 is located below the second shield 142, and the coolant inflow pipe 201 extends vertically upward from the first manifold 12 to the first shield 141 along the peripheral wall of the second shield 142, extends vertically upward a predetermined distance along the peripheral wall of the first shield 141, and then extends horizontally inward in a radial direction, and is connected to the horizontally extending first branch 203 and second branch 204.

The coolant outflow pipe 202 extends vertically upward from the second manifold 13 to the second shield 142, continues to extend vertically upward along the peripheral wall of the second shield 142 to the first shield 141, extends vertically upward along the peripheral wall of the first shield 141 for a predetermined distance, and then extends horizontally inward in the radial direction, and is connected to the horizontally extending first branch 203 and second branch 204. The inlet and the outlet of the first coolant flow passage of the heat exchanger 30 are located at both sides in the axial direction of the heat exchanger 30, and the inlet and the outlet of the second coolant flow passage are located at both upper and lower sides, respectively.

The second coolant circuit 40, the pumps, the volume compensators, the thermoelectric conversion element 50, the third coolant circuit 60, and the radiator 70 are all higher than the shield 14. The dose to which these components are exposed can be reduced on the one hand, and on the other hand, the level of activation of the coolant working fluid in the second coolant circuit 40 by the radiation of the core 10 can be reduced, so as to reduce the dose of radiation applied to the thermoelectric conversion element 50 by the activated coolant working fluid.

Referring to fig. 9, in the embodiment of the present application, the core 10 of the nuclear power source and the shielding body 14 are disposed in the moon pool 810, and since the moon soil 800 can provide a good circumferential shielding effect, the core 10 has a small influence on the radiation of the radiator 70, the pump, the control drum driving mechanism 15, etc.

The shield 14 is configured to seal the moon pool 810, and the shield 14 forms a sealed radiation-proof container with the lunar soil 800 around the moon pool 810 to prevent the radioactive radiation generated by the core 10 from leaking outside the moon pool 810.

In the embodiment of the application, the nuclear power sources are symmetrically arranged, so that the weight distribution is more uniform when the nuclear power sources are arranged in the moon pool 810, and the stability of the nuclear power sources is improved; simultaneously, two sets of radiators 70 are disposed on both sides of the shielding body 14, so that the two sets of radiators 70 are not located directly above the core 10, thereby further reducing the radiation of the core 10 to which the two sets of radiators 70 are exposed.

After successful nuclear power emission to the moon surface 820, the core 10 and the shield 14 are first installed in the moon pool 810 by an astronaut or robot. Thereafter, the core 10 is slowly turned by the control drum drive mechanism 15 from the position where the control drum 16 absorber is away from the fuel elements until the core 10 reaches a rated power steady state operation.

In operation of the core 10, the fuel elements generate heat which is carried by the first coolant to the heat exchanger 30 and then by the second coolant to the thermoelectric conversion element 50 to generate electrical energy, the cold end of the thermoelectric conversion element 50 is cooled by water, which is driven by a water pump to transfer waste heat to the radiator 70 on the lunar surface 820, and the radiator 70 radiates the waste heat.

The principle of operation of the nuclear power supply will now be described using the Topaz-II thermionic reactor core 10 as an example.

After the nuclear power source is launched and successfully landed, the reactor core 10 is placed in a pre-dug moon pool 810, and the control drum 16 absorber is slowly diverted away from the active area of the core 10 under the action of the control drum drive mechanism 15 until the reactor reaches a rated power steady state operation.

In operation of the reactor, the fuel produces 115kWt thermal power and the emitter temperature is about 180 k, and the 37 thermionic fuel elements 11 together produce about 5kWe electrical power. The sodium potassium primary loop brings the remaining thermal power of about 110kWt out of the stack with an outlet temperature of about 850K, which transfers the thermal power to the sodium potassium secondary loop in the heat exchanger 30. The outlet temperature of the heat exchanger 30 of the sodium-potassium two-circuit is about 824K, the sodium-potassium two-circuit transmits the thermal power to the Stirling generator, the thermal head temperature of the Stirling generator is about 778K, the thermal head temperature of the Stirling generator is about 425K, the thermoelectric conversion efficiency of the Stirling generator is about 26%, two opposite Stirling generators (equivalent to four Stirling generators) can generate about 28kWe of electric power together, the electric power (5 kWe) generated by the thermoionic fuel element 11 is combined, the electric power of the whole system reaches about 33kWe, and the thermoelectric conversion efficiency of the corresponding system can reach about 30%. Waste heat from the Stirling generator is carried out of the water circuit and is discharged through the radiator to the lunar surface and the space.

Therefore, on the basis of the existing thermionic reactor, the Stirling generator is introduced through the arrangement of the loop, so that the thermoelectric conversion efficiency of the system is greatly improved from less than 5% to about 30%. The embodiment of the application adopts two thermoelectric conversion modes simultaneously, so that the thermoelectric conversion efficiency of the lunar nuclear power supply is greatly improved under the condition of not remarkably improving the development difficulty.

In the related art, in order to improve the thermoelectric conversion efficiency of the nuclear power supply, the heat of the reactor core is led out by adopting a heat pipe mode, however, the embodiment of the application leads out the heat by adopting a loop mode, so that the thermoelectric conversion efficiency of the nuclear power supply can be greatly improved, and meanwhile, the adverse effect on the thermoionic fuel element 11 can be avoided, and the service life of the thermoionic fuel element 11 is shortened.

It should also be noted that, in the embodiments of the present application, the features of the embodiments of the present application and the features of the embodiments of the present application may be combined with each other to obtain new embodiments without conflict.

The present application is not limited to the above embodiments, but the scope of the application is defined by the claims.

Claims (10)

1. A nuclear power source comprising:

a core for providing heat, the core comprising a plurality of thermionic fuel elements, each of the thermionic fuel elements having a first coolant channel formed therein for flowing the first coolant;

a first manifold and a second manifold, the first coolant flowing from the first manifold through the plurality of thermionic fuel elements and then into the second manifold;

at least one heat exchanger, each of the heat exchangers having a first coolant flow passage and a second coolant flow passage capable of exchanging heat;

a first coolant circuit for receiving the first coolant from the second manifold and returning the first coolant to the first manifold after flowing through the first coolant flow passage of the at least one heat exchanger;

at least one second coolant circuit for circulating a second coolant, the second coolant in each of the second coolant circuits being capable of flowing through a second coolant flow passage of one of the heat exchangers to exchange heat with the first coolant; and

at least one thermoelectric conversion element, each of said thermoelectric conversion elements being connected to one of said second coolant loops for converting heat of one of said second coolant loops into electrical energy.

2. The nuclear power source of claim 1 wherein the number of the heat exchanger, the second coolant circuit, and the thermoelectric conversion element is two,

the first coolant circuit further includes:

a coolant inflow line in communication with the first manifold for returning the first coolant to the first manifold;

a coolant outflow line in communication with the second manifold for the second coolant to flow out of the second manifold; and

the heat exchangers are respectively arranged on the first branch and the second branch;

wherein the coolant inflow line and the coolant outflow line are communicated through the first branch and the second branch connected in parallel.

3. The nuclear power source of claim 2 wherein the first coolant loop, the two heat exchangers, the two second coolant loops, and the two thermoelectric conversion elements are each symmetrically arranged with respect to a vertical bisecting plane of the core.

4. A nuclear power source as claimed in claim 3, in which the axes of the coolant inflow and outflow lines are both located within the vertical bisecting plane.

5. A nuclear power source as claimed in claim 3, in which the first and second branches are located on either side of the vertical bisector plane.

6. The nuclear power source of claim 1 wherein the thermoelectric conversion element is a stirling generator.

7. The nuclear power source of claim 6 wherein the second coolant loop comprises a flexible bellows segment.

8. The nuclear power source of claim 1 further comprising: at least one third coolant circuit for circulating a third coolant for radiating heat from the thermoelectric conversion element; and

and at least one group of radiators, wherein each group of radiators is in heat conduction connection with one third coolant loop and is used for radiating the third coolant of the third coolant loop.

9. The nuclear power source of claim 8 wherein the third coolant loop comprises a flexible bellows segment.

10. The nuclear power source of claim 1 further comprising: a shield disposed directly above the core for shielding radioactive radiation from the core;

the at least one heat exchanger is disposed directly above the shield.