A small milliwatt level thermoelectric cell based on americium isotope heat source

Abstract

A kind of small milliwatt level thermoelectric cell based on americium isotope heat source, including battery main body, cooling device and external measuring circuit;Battery main body includes battery heat source component, shell cover, shell body, shell cover is installed on shell body;Battery heat source component is located in shell body, and heat insulation layer is filled between battery heat source component and shell body;Upper end of battery heat source component is connected with upper fixed part, lower end is connected with lower fixed part by thermoelectric power piece, and the upper end of heat conduction column is connected with lower fixed part, and the lower end is fixed with the inside of shell body.Electricity battery heat source component includes americium heat source core block, inner package shell, outer package shell, americium heat source core block is located in inner package shell, inner package shell includes inner package shell end cover, inner package shell body, and spring is filled between inner package shell end cover lower end and americium heat source core block, and helium is filled in inner package shell;Inner package shell is placed in lead shielding layer, lead shielding layer is placed in outer package shell, and outer package shell includes outer package shell body and outer package shell end plug.

Description

Technical Field

[0001] This invention relates to the field of radioisotope battery technology, specifically to a small milliwatt-level thermoelectric battery based on an americium isotope heat source. Background Technology

[0003] Existing isotope thermoelectric cells have two problems: ① 238 ① The supply of Pu is extremely limited and the cost is high; ② The power of domestic and foreign isotope thermoelectric batteries is all above 100 milliwatts; ③ The size (diameter above 500mm) and weight (tens of kilograms) of existing batteries are too large. To address the problems of existing isotope thermoelectric batteries, a longer half-life is needed. 241 Am replaces 238 Pu (Polymer) batteries have a longer service life. As small electronic devices become increasingly sophisticated and integrated, the requirements for isotope batteries are gradually shifting towards miniaturization. For example, deep-sea exploration equipment requires power for long-term standby, which necessitates lower battery output power. However, there are also limitations on the size and weight of the batteries. Americium-241 has a high thermal power, making it suitable as a heat source for miniaturized batteries.

[0004] Currently, there is no experimental research on thermoelectric batteries with Am-241 heat source in China, and there is no successful experience in miniaturizing thermoelectric isotope batteries, either domestically or internationally. In order to fill the gap in related fields, this patent provides a small milliwatt-level thermoelectric battery device based on the Americium-241 heat source. Summary of the Invention

[0005] The purpose of this invention is to address the problems of extremely limited supply and high cost of heat source materials for traditional isotope thermoelectric batteries, and the current lack of research on milliwatt-level small Am-241 thermoelectric batteries both domestically and internationally. This invention provides a small milliwatt-level thermoelectric battery based on an americium isotope heat source. This battery uses static thermoelectric conversion to convert part of the decay heat into electrical energy, requires no maintenance, and exhibits high reliability and stability. It is primarily used to power small devices such as detectors in extreme environments.

[0006] The technical solution of the present invention is as follows: a small milliwatt-level thermoelectric battery based on an americium isotope heat source, comprising a battery body, a cooling device and an external measurement circuit; The battery body includes a battery heat source component, a casing cover, and a casing. The casing cover is installed on the casing. The battery heat source component is located in the casing, and an insulation layer is filled between the battery heat source component and the casing. The upper end of the battery heat source component is connected to an upper fixing component, and the lower end is connected to a lower fixing component through a thermoelectric generator. The upper end of the heat-conducting column is connected to the lower fixing component, and the lower end is fixed to the inside of the casing.

[0007] The battery heat source component includes an americium heat source core, an inner shell, and an outer shell. The americium heat source core is located in the inner shell. The inner shell includes an inner shell end cap and an inner shell housing. A spring is filled between the lower end of the inner shell end cap and the americium heat source core, and the inner shell is filled with helium. The inner shell is placed inside a lead shielding layer, and the lead shielding layer is placed in the outer shell. The outer shell includes an outer shell housing and an outer shell end plug.

[0008] The inner shell end cap and the inner shell body are welded together, and the outer shell body and the outer shell end plug are welded together.

[0009] A thermoelectric generator consists of an electrical conductor and thermoelectric components, with the upper end being the hot end and the lower end being the cold end.

[0010] The external measurement circuit includes a voltmeter, a measurement load circuit, and an ammeter. The voltmeter is connected to both ends of the load circuit, while the ammeter, the measurement load circuit, and the battery body form a loop.

[0011] The cooling device contains circulating cooling water, and its side has the water inlet and outlet.

[0012] The outer cover is fixed to the outer shell with bolts, and the bolts restrict the movement of the insulation layer. The bottom of the outer shell is arc-shaped.

[0013] The upper and lower fixing parts are connected by plastic bolts.

[0014] The insulation layer is made of rigid polyurethane foam, while the outer cover and outer shell are made of aluminum alloy.

[0015] The significant advantages of this invention are: This invention fills the gap in domestic americium isotope battery structure design, provides a new development path, and americium isotopes have a longer half-life and longer service life.

[0016] This invention is specially designed for deep-sea environments, with special designs for the size of the heat source and the thickness of the insulation layer. This reduces the contact area between the shell and the insulation layer, resulting in a smaller heat leakage area of ​​the insulation layer, reducing battery heat dissipation loss, achieving better insulation effect, reaching a higher heat source temperature, and improving the heat utilization rate of the heat source.

[0017] Based on the application environment, this invention changes the heat dissipation method to water cooling, which has a stronger heat dissipation capacity and does not require an additional water cooling device. This invention also places the shielding layer between the inner and outer casings, reducing the weight of the shielding layer and thus reducing the overall battery weight.

[0018] Based on the above structural design, a milliwatt-level americium battery device was successfully obtained, which can provide power for small devices such as detectors in deep-sea environments. Attached Figure Description

[0019] Figure 1This is a schematic diagram of a small milliwatt-level thermoelectric battery based on an americium isotope heat source; Figure 2 This is a schematic diagram of the main structure of the battery; Figure 3 This is a schematic diagram of the main structure of the battery.

[0020] Figure 4 Battery heat source components and fasteners; Figure 5 Battery heat source components and fasteners; Figure 6 Schematic diagram of the battery cooling device; Figure 7 Schematic diagram of the principle of thermoelectric generator; Figure 8 Schematic diagram of battery insulation layer; The markings in the diagram and their corresponding component names are as follows: 1-Voltmeter; 2-Load circuit; 3-Ammeter; 4-Battery body; 5-Cooling device; 21-Outer casing cover; 22-Outer casing body; 23-Insulation layer; 24-Upper fixing component; 25-Fuel pellet; 26-Thermoelectric generator; 27-Heat conduction column; 28-Plastic bolt; 29-Outer casing metal bolt; 31-Outer shell end cap; 32-Outer shell housing; 33-Lead shielding layer; 34-Inner shell housing; 35-Spring; 36-Inner shell end cap; 37-Lower fixing component; 41-Cooling water inlet; 42-Cooling water outlet; 51-Hot end heat collection component; 52-Electrical conductor; 53-Cold end heat dissipation component; 54-Thermoelectric element. Detailed Implementation

[0021] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0022] The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms “a,” “the,” and “the” used in one or more embodiments of this application and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0023] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this application, and similarly, second may also be referred to as first.

[0024] The specific technical content of the present invention will now be described with reference to the accompanying drawings; like Figure 1 As shown, a small milliwatt-level thermoelectric battery based on an americium isotope heat source includes a battery body 4, a cooling device 5, and an external measurement circuit. The bottom of the battery body 4 is in contact with the surface of the cooling device 5. like Figure 7 As shown, the cooling device 5 contains circulating cooling water, and its side has a water inlet 41 and an outlet 42. The thermoelectric generator achieves thermoelectric conversion through the temperature difference between the heat source and the cooling device. The thermoelectric generator 26 is connected to the load circuit. The ammeter 3 and voltmeter 1 measure the current in the load circuit 2 and the voltage across the load terminals, thereby obtaining the output power of the thermoelectric generator.

[0025] like Figure 2-3 As shown, the battery body 4 includes a battery heat source component, a casing cover 21, and a casing 22. The casing cover 21 is installed on the casing 22 and fixed by four bolts 29, which also restrict the movement of the insulation layer 23. The bottom of the casing 22 is shaped into an arc to fit the environment, and water cooling is achieved through the environment without the need for additional water cooling devices.

[0026] The battery heat source component is located in the outer casing 22, and an insulation layer 23 is filled between the battery heat source component and the outer casing 22; The thermal insulation performance of the insulation layer 23 affects the utilization rate of the battery's heat release. The factors affecting the thermal insulation performance are the thermal conductivity of the insulation material itself and the thickness of the insulation layer. The utilization rate of battery heat can be increased by selecting materials with low thermal conductivity (rigid polyurethane foam) and appropriate insulation layer thickness.

[0027] like Figure 4 As shown, the battery heat source component includes an americium heat source core 25, an inner shell, and an outer shell. The americium heat source core 25 is located in the inner shell. The inner shell includes an inner shell end cap 36 and an inner shell housing 34. A spring 35 is filled between the lower end of the inner shell end cap 36 and the americium heat source core 25, and the inner shell is filled with helium. The inner shell is placed inside a lead shielding layer 33, and the lead shielding layer 33 is placed in the outer shell. The outer shell includes an outer shell housing 32 and an outer shell end plug 31. Considering the radioactivity (mainly gamma rays) of americium dioxide and the redundancy of shielding layer weight, a lead shielding layer 33 is added between the inner and outer shells as a radiation shielding layer. This design has the following advantages: ① Placing the lead shielding layer between the inner and outer shells reduces the size and weight of the shielding layer; ② In traditional designs where the shielding layer is outside the shell, the dose during the assembly and welding of the inner and outer shells cannot be avoided. However, with the lead shielding layer between the inner and outer shells, the dose during the assembly and welding of the outer shell can be greatly reduced, thus reducing the dose harm to operators.

[0028] Specifically, the inner shell end cap 36 and the inner shell 34 are welded together, and the outer shell 32 and the outer shell end plug 31 are welded together. like Figure 5 As shown, the upper end of the battery heat source component is connected to the upper fixing member 24, and the lower end is connected to the lower fixing member 37 through the thermoelectric generator 26. The upper end of the heat-conducting column 27 is connected to the lower fixing member 37 by a thread, and the lower end is welded to the inside of the outer shell 22. The upper fixing member 24 and the lower fixing member 37 are connected by plastic bolts 28. The function of the upper fixing member 24 and the lower fixing member 37 is to fix the battery heat source component and the thermoelectric generator 26 to prevent gaps between them from causing poor heat transfer. The heat insulation performance of the insulation layer 23 affects the utilization rate of the heat released by the battery heat source component, and the factors affecting the heat insulation performance include the thermal conductivity of the insulation material itself and the utilization rate of the battery heat in the insulation layer.

[0029] like Figure 7 As shown, americium isotope decay energy is deposited in the battery heat source component in the form of thermal energy. The thermoelectric generator 26 converts the thermal energy of the battery heat source component into electrical energy output when there is a temperature difference between the hot end 51 and the cold end 53. The greater the temperature difference, the higher the efficiency of the thermoelectric generator 26. Part of the heat from the heat source is utilized by the thermoelectric generator 26 for thermoelectric conversion, and part is dissipated through the insulation layer 23. The smaller the contact area between the insulation layer 23 and the high-temperature surface of the inner heat source, the less heat is lost due to heat leakage, the higher the temperature of the isotope heat source, and the higher the thermoelectric conversion efficiency can be obtained. Through design, the outer shell size is designed with a height-to-diameter ratio of 1:1 (minimum surface area) to reduce heat leakage. The connecting bolts 28 of the fixing parts are made of plastic to reduce heat transfer between the upper fixing part 24 and the lower fixing part 37, reduce heat leakage, and improve the utilization rate of the heat released by the heat source.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0031] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0032] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0033] The preferred embodiments disclosed above are merely illustrative of this application. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this application. These embodiments are selected and specifically described in this application to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize this application.

Claims

1. A small milliwatt-level thermoelectric battery based on an americium isotope heat source, characterized in that: It includes the battery body (4), cooling device (5) and external measurement circuit; The battery body (4) includes a battery heat source component, a casing cover (21), and a casing (22). The casing cover (21) is installed on the casing (22). The battery heat source component is located in the casing (22), and a heat insulation layer (23) is filled between the battery heat source component and the casing (22). The upper end of the battery heat source component is connected to the upper fixing member (24), and the lower end is connected to the lower fixing member (37) through the thermoelectric generator (26). The upper end of the heat-conducting column (27) is connected to the lower fixing member (37), and the lower end is fixed inside the casing (22).

2. The small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 1, characterized in that: The battery heat source component includes an americium heat source core (25), an inner shell, and an outer shell. The americium heat source core (25) is located in the inner shell. The inner shell includes an inner shell end cap (36) and an inner shell housing (34). A spring (35) is filled between the lower end of the inner shell end cap (36) and the americium heat source core (25), and the inner shell is filled with helium. The inner shell is placed inside a lead shielding layer (33), and the lead shielding layer (33) is placed in the outer shell. The outer shell includes an outer shell housing (32) and an outer shell end plug (31).

3. A small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 2, characterized in that: The inner shell end cap (36) and the inner shell shell (34) are welded together, and the outer shell shell (32) and the outer shell end plug (31) are welded together.

4. A small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 2, characterized in that: The thermoelectric generator (26) includes an electrical conductor (52) and a thermoelectric element (54), with the upper end of the thermoelectric generator (26) being the hot end (51) and the lower end being the cold end (53).

5. A small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 1, characterized in that: The external measuring circuit includes a voltmeter (1), a measuring load circuit (2), and an ammeter (3). The voltmeter (1) is connected to both ends of the load circuit (2), while the ammeter (3), the measuring load circuit (2), and the battery body (4) form a loop.

6. A small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 1, characterized in that: The cooling device (5) contains circulating cooling water, and its side has a cooling device inlet (41) and outlet (42).

7. A small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 1, characterized in that: The outer cover (21) and the outer shell (22) are fixed by bolts (29), and the bolts (29) restrict the movement of the insulation layer (23). The bottom of the outer shell (22) is arc-shaped.

8. A small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 1, characterized in that: The upper fixing member (24) and the lower fixing member (37) are connected by plastic bolts (28).

9. A small milliwatt-level thermoelectric battery based on an americium isotope heat source according to claim 1, characterized in that: The insulation layer (23) is made of rigid polyurethane foam, and the outer cover (21) and outer shell (22) are made of aluminum alloy.

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