A decay heat Stirling converter for space use

Abstract

The present invention discloses a space-use decay heat Stirling conversion device, which relates to the field of nuclear energy utilization and includes: a double-ended free-piston Stirling motor, a fan-shaped liquid droplet radiation heat dissipation system for space, a Stirling expansion chamber, a plutonium-238 fuel ring, a thermal insulation layer, a shielding layer, a control and power transmission and distribution system, annular fins, a droplet emission stage, a radiation heat dissipation cavity, a droplet collection stage, a tube bundle channel, and an electromagnetic pump. The present invention utilizes the decay heat generated by the plutonium-238 fuel as a heat source, converts the decay heat into electrical energy through a double-ended free-piston Stirling motor, removes waste heat through a fan-shaped liquid droplet radiation heat dissipation system for space, and improves the utilization efficiency of the heat source using a dynamic Stirling converter. The opposing arrangement of the Stirling converters reduces noise and vibration, and the fan-shaped liquid droplet radiation heat dissipation system provides efficient and compact waste heat removal, further ensuring system efficiency and reducing the overall volume, thereby meeting the requirements of space missions for higher power and more efficient energy supply.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear energy utilization, and in particular to a decay heat Stirling conversion device for space use. Background Art

[0002] Nuclear batteries utilize the decay of radioactive isotopes to release energetic particles (such as alpha particles, beta particles, and gamma rays) and convert their energy into electricity. They have been successfully used as power sources for spacecraft, pacemakers, and some specialized military applications. The amount and rate of energy released during decay are unaffected by external factors such as temperature, chemical reactions, pressure, and electromagnetic fields. Therefore, they can operate over a wide temperature range and in harsh environments.

[0003] The free-piston Stirling engine is a structural form of the Stirling engine. It eliminates the crankshaft structure of the traditional Stirling engine and has the characteristics of high thermoelectric conversion efficiency, compact structure, good heat source adaptability, high reliability, and long life. It has broad application prospects in space power supply, underwater power, new energy fields, and distributed power supply.

[0004] Currently, nuclear batteries are almost all "static thermoelectric" temperature difference generators, which have low thermoelectric conversion efficiency and require the consumption of large amounts of expensive radioactive isotope fuel. Currently, space Stirling converters are mainly combined with nuclear reactors, and the heat of the reactor is extracted and transferred to the Stirling converter through complex alkali metal loops or high-temperature heat pipes. The reactor system is complex to control and has complex coupling effects with the Stirling system. This poses a great challenge to the safe operation of the reactor-Stirling power generation system. For space missions with medium and low power requirements, a simple, safe and reliable power supply system is urgently needed. Summary of the Invention

[0005] In view of this, the present invention provides a decay heat Stirling converter for space use to overcome the above-mentioned defects.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A space decay heat Stirling converter device comprises: a double-ended free piston Stirling motor 1, a space sector droplet radiation heat dissipation system 2, a Stirling expansion chamber 3, a plutonium-238 fuel ring 4, an insulation layer 5, a shielding layer 6, and a control and power transmission and distribution system 7; the double-ended free piston Stirling motor 1 is two, the two Stirling converters are arranged opposite each other, the two double-ended free piston Stirling motors 1 share a Stirling expansion chamber 3, and the two Stirling converter pistons are controlled by the control and power transmission and distribution system 7. The same operating state is used to eliminate vibration of the Stirling converter during operation to the greatest extent possible and reduce operating noise; sufficient margin is provided for the Stirling thermoelectric conversion device so that even if a single Stirling converter fails, it can still operate stably through another one; a space-use fan-shaped liquid droplet radiation heat dissipation system 2 is set on the cooler of the double-ended free piston Stirling motor 1 to remove waste heat; a plutonium-238 fuel ring 4 is arranged outside the Stirling expansion chamber 3, an insulation layer 5 is arranged outside the plutonium-238 fuel ring 4, and a shielding layer 6 is arranged outside the insulation layer 5;

[0008] The double-ended free-piston Stirling motor 1 is used to absorb the decay heat generated by the plutonium-238 fuel ring 4 and efficiently convert the decay heat into electrical energy;

[0009] The space fan-shaped droplet radiation heat dissipation system 2 is used to extract the waste heat generated by the double-ended free piston Stirling motor 1 to ensure the thermoelectric conversion efficiency;

[0010] The Stirling expansion chamber 3 is connected to the plutonium-238 fuel ring 4, and the working medium expands due to heat in the Stirling expansion chamber 3;

[0011] The plutonium-238 fuel ring 4 is used to continuously generate heat;

[0012] The thermal insulation layer 5 is used to reduce the heat dissipation loss of the plutonium-238 fuel ring 4;

[0013] The shielding layer 6 is used for radiation protection to prevent surrounding workers and the public from being harmed by radioactive radiation;

[0014] The control and power transmission and distribution system 7 is used for the control and system power storage and distribution of the double-ended free piston Stirling motor 1 and the space fan-shaped droplet radiation heat dissipation system 2;

[0015] The annular fins 8 are used to enhance the flow heat exchange between the condensing section of the double-ended free piston Stirling motor 1 and the cooling medium in the space fan-shaped droplet radiation heat dissipation system 2;

[0016] The droplet emission stage 9 is used to disperse the heat exchange medium from the tube bundle channel 12 into sufficiently small droplets;

[0017] The radiation heat dissipation cavity 10 is used to accommodate the droplets generated by the droplet emission stage 9 and allow them to perform radiation heat exchange with the space environment;

[0018] The droplet collecting stage 11 is used to collect the working fluid after heat exchange in the radiation heat dissipation cavity 10;

[0019] The tube bundle channel 12 is used to connect the droplet emission stage 9 and the droplet collection stage 11 to form a flow circuit;

[0020] The droplet electromagnetic pump 13 is used to drive the cooling medium in the fan-shaped droplet radiation heat dissipation system 2 for space.

[0021] Optionally, the double-ended free-piston Stirling motor 1 is made of titanium to meet the mass restrictions of space missions.

[0022] Optionally, the fan-shaped droplet radiation heat dissipation system 2 for space is composed of an annular fin 8, a droplet emission stage 9, a radiation heat dissipation cavity 10, a droplet collection stage 11, a tube bundle channel 12 and an electromagnetic pump 13. The bottom of the annular fin 8 is connected to the outside of the cooler of the double-ended free piston Stirling motor 1, the fin end is connected to the droplet emitter 9, the two sides of the radiation heat dissipation cavity 10 are respectively connected to the emission surface of the droplet emitter 9 and the collection surface of the droplet collection stage 11, the tube bundle channel 12 is respectively connected to the inlet of the droplet emitter 9 and the outlet of the droplet collection stage 11, and the electromagnetic pump 13 is arranged in the tube bundle channel. 12 outside, controlled by the control and power distribution system 7; the heat exchange medium in the space fan-shaped droplet radiation heat dissipation system is a conductive liquid, which exchanges heat with the annular fin 8 under the drive of the electromagnetic pump 13, and is sprayed into fine droplets by the droplet emission stage 9 to exchange heat with the space environment in the radiation heat dissipation cavity 10 by radiation. After heat exchange, the droplets are aggregated into a stream at the droplet collection stage 11 and exchange heat with the annular fin 8 again through the tube bundle channel 12; the space fan-shaped droplet radiation heat dissipation system 2 can select two sets of symmetrical arrangements or four sets to form an annular droplet radiation heat dissipation system according to different heat dissipation requirements.

[0023] Optionally, the aperture of the droplet emission stage 9 is less than 1 mm, and the diameter of the atomized droplets is less than 100 microns.

[0024] Optionally, the tube bundle channels 12 are arranged in parallel along the axial direction of the Stirling expansion chamber 3 , with a tube diameter of less than 1 cm, and each tube bundle channel is equipped with a set of micro electromagnetic pump systems.

[0025] Optionally, the thermal insulation layer 5 is made of aerogel, which has excellent thermal insulation performance and light weight, and is suitable for space applications.

[0026] Optionally, the control and power transmission and distribution system 7 includes a Stirling control system, an electromagnetic pump control system, a power distribution output system and an energy storage system.

[0027] Through the above technical solutions, it can be seen that compared with the existing technology, the present invention discloses a space-based decay heat Stirling conversion device, which uses the decay heat generated by plutonium-238 fuel as a heat source, converts the decay heat into electrical energy through a double-ended opposed free-piston Stirling motor, and uses a space-based fan-shaped droplet radiation heat dissipation system to conduct waste heat, and uses a dynamic Stirling converter to improve the utilization efficiency of the heat source. The Stirling converters are arranged in opposition to each other to reduce noise and vibration, and the fan-shaped droplet radiation heat dissipation system provides efficient and compact waste heat discharge, further ensuring the efficiency of the system and reducing the overall volume. The space-based decay heat Stirling conversion device in the present invention improves the utilization rate of the decay heat of plutonium-238 fuel and has a high thermoelectric conversion efficiency; the system is compact and reliable, meeting the needs of space operations for higher power and efficiency energy supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0029] Figure 1 This is a schematic structural diagram of a decay heat Stirling converter device for space use according to the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the fan-shaped droplet radiation heat dissipation system for space;

[0031] Among them, there are 1 double-ended opposed free-piston Stirling motor, 2 fan-shaped droplet radiation heat dissipation system for space, 3 Stirling expansion chamber, 4 plutonium-238 fuel ring, 5 insulation layer, 6 shielding layer, 7 control and power transmission and distribution system, 8 annular fins, 9 droplet emission stage, 10 radiation heat dissipation cavity, 11 droplet collection stage, 12 tube bundle channel, and 13 electromagnetic pump. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] The embodiment of the present invention discloses a space decay heat Stirling converter device, such as Figure 1As shown, it includes a double-ended opposed free-piston Stirling motor 1, a fan-shaped droplet radiation system for space 2, a Stirling expansion chamber 3, a plutonium-238 fuel ring 4, an insulation layer 5, a shielding layer 6, a control and power transmission and distribution system 7, annular fins 8, a droplet emission stage 9, a radiation heat dissipation cavity 10, a droplet collection stage 11, a tube bundle channel 12, and an electromagnetic pump 13.

[0034] The double-ended opposed free-piston Stirling motor 1 is used to absorb the decay heat generated by the plutonium-238 fuel ring 4 and efficiently convert the decay heat into electrical energy.

[0035] The fan-shaped liquid droplet radiation heat dissipation system 2 for space use is used to remove waste heat generated by the double-ended free piston Stirling motor 1 to ensure the efficiency of thermoelectric conversion;

[0036] The Stirling expansion chamber 3 is connected to the plutonium-238 fuel 4, and the working medium expands due to heat in the Stirling expansion chamber 3;

[0037] Plutonium-238 fuel ring 4, used to continuously generate heat;

[0038] A thermal insulation layer 5, used to reduce heat dissipation losses of the plutonium-238 fuel ring 4;

[0039] Shielding layer 6 is used for radiation protection to prevent surrounding workers and the public from being harmed by radioactive radiation;

[0040] The control and power transmission and distribution system 7 is used for the control and system power storage and distribution of the double-ended free piston Stirling motor 1 and the space fan-shaped droplet radiation heat dissipation system 2.

[0041] The annular fins 8 are used to enhance the flow and heat exchange of the cooling medium between the condensing section of the double-ended free piston Stirling motor 1 and the space fan-shaped liquid droplet radiation heat dissipation system 2.

[0042] The droplet emission stage 9 is used to disperse the heat exchange medium from the tube bundle channel 12 into sufficiently small droplets.

[0043] The radiation heat dissipation cavity 10 is used to accommodate the droplets generated by the droplet emission stage 9 and allow them to perform radiation heat exchange with the space environment.

[0044] The droplet collecting stage 11 is used to collect the working fluid after heat exchange in the radiation heat dissipation cavity 10.

[0045] The tube bundle channel 12 is used to connect the droplet emission stage 9 and the droplet collection stage 11 to form a flow circuit.

[0046] The droplet electromagnetic pump 13 is used to drive the cooling medium in the fan-shaped droplet radiation heat dissipation system 2 for space.

[0047] In this embodiment, the decay heat generated by plutonium-238 fuel is used as a heat source. This decay heat is converted into electrical energy via a double-ended, free-piston Stirling motor. A space-based, fan-shaped droplet radiant heat dissipation system is used to dissipate the waste heat, and a dynamic Stirling converter is employed to improve heat source efficiency. The opposed Stirling arrangement reduces noise and vibration, while the space-based, fan-shaped droplet radiant heat dissipation system provides efficient and compact waste heat removal, further ensuring conversion efficiency and reducing overall volume.

[0048] In this embodiment, there are two double-ended free-piston Stirling motors 1, and the two Stirling converters are arranged opposite to each other. The two double-ended free-piston Stirling motors 1 share a Stirling expansion chamber 3, and the two Stirling converter pistons are controlled to have the same operating state through the control and power transmission and distribution system 7, which can eliminate the vibration of the Stirling converter during operation and reduce the operating noise to the greatest extent; provide sufficient margin for the Stirling thermoelectric conversion device, that is, if a single Stirling converter fails, it can still work stably through the other one; the motor material can be selected from titanium metal to meet the mass restrictions of space missions.

[0049] In this embodiment, the fan-shaped droplet radiation heat dissipation system 2 for space is composed of an annular fin 8, a droplet emission stage 9, a radiation heat dissipation cavity 10, a droplet collection stage 11, a tube bundle channel 12 and an electromagnetic pump 13. The bottom of the annular fin 8 is connected to the outside of the cooler of the double-ended free piston Stirling motor 1, the fin end is connected to the droplet emitter 9, the two sides of the radiation heat dissipation cavity 10 are respectively connected to the emission surface of the droplet emitter 9 and the collection surface of the droplet collection stage 11, the tube bundle channel 12 is respectively connected to the inlet of the droplet emitter 9 and the outlet of the droplet collection stage 11, and the electromagnetic pump 13 is arranged in the tube bundle channel. 12 outside, controlled by the control and power distribution system 7; the heat exchange medium in the space fan-shaped droplet radiation heat dissipation system is a conductive liquid, which exchanges heat with the annular fin 8 under the drive of the electromagnetic pump 13, and is sprayed into fine droplets by the droplet emission stage 9 to exchange heat with the space environment in the radiation heat dissipation cavity 10 by radiation. After heat exchange, the droplets are aggregated into a stream at the droplet collection stage 11 and exchange heat with the annular fin 8 again through the tube bundle channel 12; the space fan-shaped droplet radiation heat dissipation system 2 can choose two sets of symmetrical arrangements or four sets to form an annular droplet radiation heat dissipation system according to different heat dissipation requirements.

[0050] In this embodiment, the thermal insulation layer 5 is made of aerogel, which has excellent thermal insulation performance and is lightweight, and is very suitable for space applications.

[0051] In this embodiment, the control and power transmission and distribution system 7 includes a Stirling control system, an electromagnetic pump control system, a power distribution output system and an energy storage system.

[0052] In this embodiment, the aperture of the droplet emission stage 9 is less than 1 mm, and the diameter of the atomized droplets is less than 100 microns.

[0053] In this embodiment, the tube bundle channels 12 are arranged in parallel along the axial direction of the Stirling expansion chamber 3 , with a tube diameter of less than 1 cm. Each tube bundle channel is equipped with a micro electromagnetic pump system.

[0054] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0055] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A decay heat Stirling converter for space use, characterized in that: include: A double-ended free piston Stirling motor (1), a space-use fan-shaped liquid droplet radiation heat dissipation system (2), a Stirling expansion chamber (3), a plutonium-238 fuel ring (4), a heat insulation layer (5), a shielding layer (6), and a control and power transmission and distribution system (7); the double-ended free piston Stirling motor (1) is two, the two Stirling converters are arranged opposite to each other, the two double-ended free piston Stirling motors (1) share a Stirling expansion chamber (3), and the two Stirling converter pistons are controlled by the control and power transmission and distribution system (7) to have the same operating state. state, so as to eliminate the vibration of the Stirling converter during operation to the greatest extent and reduce the operating noise; provide sufficient margin for the Stirling thermoelectric conversion device, so that even if a single Stirling converter fails, it can still work stably through another one; a space fan-shaped liquid droplet radiation heat dissipation system (2) is arranged on the cooler of the double-end opposed free piston Stirling motor (1) to conduct waste heat, a plutonium-238 fuel ring (4) is arranged outside the Stirling expansion chamber (3), a heat insulation layer (5) is arranged outside the plutonium-238 fuel ring (4), and a shielding layer (6) is arranged outside the heat insulation layer (5); The double-ended opposed free piston Stirling motor (1) is used to absorb the decay heat generated by the plutonium-238 fuel ring (4) and efficiently convert the decay heat into electrical energy; The space fan-shaped liquid droplet radiation heat dissipation system (2) is used to discharge waste heat generated by the double-ended free piston Stirling motor (1) to ensure the efficiency of thermoelectric conversion; The Stirling expansion chamber (3) is connected to the plutonium-238 fuel ring (4), and the working medium expands when heated in the Stirling expansion chamber (3); The plutonium-238 fuel ring (4) is used to continuously generate heat; The thermal insulation layer (5) is used to reduce the heat dissipation loss of the plutonium-238 fuel ring (4); The shielding layer (6) is used for radiation protection to prevent surrounding workers and the public from being harmed by radioactive radiation; The control and power transmission and distribution system (7) is used for the control and system power storage and distribution of a double-ended free piston Stirling motor (1) and a space fan-shaped droplet radiation heat dissipation system (2); The annular fin (8) is used to enhance the flow heat exchange between the condensing section of the double-ended free piston Stirling motor (1) and the cooling medium in the space fan-shaped liquid droplet radiation heat dissipation system (2); A droplet emission stage (9) for dispersing the heat exchange medium from the tube bundle channel (12) into sufficiently small droplets; A radiation heat dissipation cavity (10) is used to accommodate the droplets generated by the droplet emission stage (9) and allow the droplets to exchange heat with the space environment through radiation; A droplet collection stage (11) is used to collect the working fluid after heat exchange in the radiation heat dissipation cavity (10); The tube bundle channel (12) is used to connect the droplet emission stage (9) and the droplet collection stage (11) to form a flow circuit; A liquid drop electromagnetic pump (13) is used to drive the cooling medium in the fan-shaped liquid drop radiation heat dissipation system (2) for space.

2. The decay heat Stirling converter for space use according to claim 1, characterized in that: The material of the double-ended opposed free piston Stirling motor (1) is titanium metal to meet the mass restrictions of space missions.

3. The decay heat Stirling converter for space use according to claim 1, characterized in that: The fan-shaped liquid droplet radiation heat dissipation system (2) for space is composed of an annular fin (8), a liquid droplet emission stage (9), a radiation heat dissipation cavity (10), a liquid droplet collection stage (11), a tube bundle channel (12) and an electromagnetic pump (13). The bottom of the annular fin (8) is connected to the outer side of the cooler of the double-ended free piston Stirling motor (1), the fin end is connected to the liquid droplet emission stage (9), the two sides of the radiation heat dissipation cavity (10) are respectively connected to the emission surface of the liquid droplet emission stage (9) and the collection surface of the liquid droplet collection stage (11), the tube bundle channel (12) is respectively connected to the inlet of the liquid droplet emission stage (9) and the outlet of the liquid droplet collection stage (11), and the electromagnetic pump (13) is arranged On the outside of the tube bundle channel (12), it is controlled by the control and power distribution system (7); the heat exchange medium in the space fan-shaped droplet radiation heat dissipation system is a conductive liquid, which exchanges heat with the annular fin (8) under the drive of the electromagnetic pump (13), and is sprayed into fine droplets through the droplet emission stage (9) to perform radiation heat exchange with the space environment in the radiation heat dissipation cavity (10). After the heat exchange, the droplets are aggregated into a stream at the droplet collection stage (11) and exchange heat with the annular fin (8) again through the tube bundle channel (12); the space fan-shaped droplet radiation heat dissipation system (2) is selected according to different heat dissipation requirements to select two sets of symmetrical arrangements or four sets to form an annular droplet radiation heat dissipation system.

4. The decay heat Stirling converter for space use according to claim 3, characterized in that: The aperture of the droplet emission stage (9) is less than 1 mm, and the diameter of the atomized droplets is less than 100 microns.

5. The decay heat Stirling converter for space use according to claim 3, characterized in that: The tube bundle channels (12) are arranged in parallel along the axial direction of the Stirling expansion chamber (3), with a tube diameter of less than 1 cm, and each tube bundle channel is provided with a set of micro electromagnetic pump systems.

6. The decay heat Stirling converter for space use according to claim 1, characterized in that: The thermal insulation layer (5) is made of aerogel, which has excellent thermal insulation performance and is lightweight, and is suitable for space applications.

7. The decay heat Stirling converter for space use according to claim 1, characterized in that: The control and power transmission and distribution system (7) includes a Stirling control system, an electromagnetic pump control system, a power distribution output system and an energy storage system.

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