CN-121997558-A - Multi-component bismuth telluride temperature zone adaptive multi-stage thermoelectric refrigerator design method

CN121997558ACN 121997558 ACN121997558 ACN 121997558ACN-121997558-A

Abstract

A multi-component bismuth telluride temperature zone adaptive multi-stage thermoelectric refrigerator design method comprises the steps of preparing bismuth telluride materials with various components and different thermoelectric properties, testing the change relation of thermoelectric parameters of the bismuth telluride materials in a near-room temperature range along with temperature, screening bismuth telluride materials with highest thermoelectric optimal values in different temperature zones based on test results, drawing curves of thermoelectric parameters changing along with temperature, fitting obtained high-order term expressions taking temperature as variables, setting initial values of logarithms and initial values of grain sizes of elements of each level of the multi-stage thermoelectric refrigerator, substituting the obtained fitting expressions into a heat balance equation set of the multi-stage thermoelectric refrigerator according to the temperature zones, solving a heat balance equation set through iteration of the logarithms and the grain sizes of the elements of each level, and completing design. The method can realize the structural optimization of the multi-stage thermoelectric refrigerator, realize the material temperature area adaptation and the structural parameter collaborative optimization, and obviously improve the refrigeration temperature difference and the refrigeration power.

Inventors

WU YUE
QI YAQING
HOU XUFENG
ZHENG BIN
LI WENPENG
HAN ZICHUAN
LIANG LIANG
CHEN YISONG
YU QI
LIU JIAXIN
MA HONGKUI

Assignees

中国电子科技集团公司第十八研究所

Dates

Publication Date: 20260508
Application Date: 20251226

Claims (10)

1. A method of designing a multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator, comprising the steps of: S1, preparing bismuth telluride materials with various components and different thermoelectric properties; S2, testing the change relation of thermoelectric parameters of a plurality of groups of bismuth telluride materials along with temperature in a near room temperature range; S3, screening the bismuth telluride material with the highest thermoelectric figure of merit in different temperature areas based on a test result, drawing a curve of thermoelectric parameter transformation along with temperature, and fitting the obtained high-order term expression taking the temperature as a variable; s4, setting initial values of logarithms and initial values of grain sizes of all level elements of the multi-level thermoelectric refrigerator, and substituting the fitting expression obtained in the step S3 into a thermal balance equation set of the multi-level thermoelectric refrigerator according to a temperature zone for analysis; S5, solving a heat balance equation set by iterating the logarithm and the grain size of each level element to obtain optimal design parameters, and completing the design of the multi-stage electrothermal refrigerator.
2. The method for designing a multi-component bismuth telluride temperature zone-adaptive multi-stage thermoelectric refrigerator according to claim 1, wherein in the step S1, the bismuth telluride material is an N-type bismuth telluride crystal bar and a P-type bismuth telluride crystal bar prepared by a zone melting method or a hot extrusion method, and the compressive strength is more than or equal to 80MPa.
3. A multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator design method as set forth in claim 2 wherein for the bismuth telluride material used in the preparation of N-type bismuth telluride crystal ingot, the chemical formula is , wherein, x is more than or equal to 0 and less than or equal to 0.8,0 y is more than or equal to 0.5; for the bismuth telluride material used for preparing the P-type bismuth telluride crystal rod, the chemical formula is as follows , wherein, x is more than or equal to 0 and less than or equal to 0.8,0 y is more than or equal to 0.5.
4. A multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator design method as claimed in claim 2 or 3 wherein said bismuth telluride material used in N-type bismuth telluride crystal ingot is doped with group VIIA halogen compound, said halogen compound being 0-1.0wt%, selected from the group consisting of 、、、、 One or more of them.
5. The method of claim 1, wherein the thermoelectric parameter test is performed in step S2 by using a low temperature physical property measurement system or introducing liquid nitrogen into a thermoelectric performance test bench, wherein the test temperature points include 173K, 198K, 223K, 248K, 273K, 298K, 323K, and the thermoelectric parameters include electric conductivity σ, seebeck coefficient α, and thermal conductivity κ.
6. A multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator design method as set forth in claim 5 wherein the different temperature zones in step S3 include at least: A first temperature zone [173K, 223K); a second temperature region [223K, 273K); A third temperature region [273K,323K ]; And respectively screening the N-type bismuth telluride material and the P-type bismuth telluride material of at least one component with the highest thermoelectric figure of merit (ZT) in each temperature zone.
7. A multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator design method as set forth in claim 6 wherein numerical fitting is employed to establish conductivity for each temperature zone of said bismuth telluride material of both the N-type and P-type that is optimal for thermoelectric performance Seebeck coefficient Thermal conductivity The higher order mathematical expression as a function of temperature, where m=1, 2,3, corresponds to three temperature zones, respectively.
8. A multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator design method as set forth in any one of claims 4-7 wherein in the multi-stage thermoelectric refrigerator structure constructed in step S4: The uppermost layer is a1 st stage cold end; The middle level is from the top down in turn from the 2 nd level to the i-1 th level; The bottommost layer is the i-th grade hot end; wherein i is the total layer number of the multi-stage thermoelectric refrigerator, i is more than or equal to 3 and less than or equal to 6; And setting the initial value of the logarithm of each level element from the 1 st level cold end to the i th level hot end as 、 ... The initial value of the cross-sectional area of each level element is 、 ... The initial value of the element height of each level is 、 ... 。
9. The method for designing a multi-component bismuth telluride temperature zone adaptive multi-stage thermoelectric refrigerator according to claim 8, wherein the heat balance equation set of the multi-stage thermoelectric refrigerator in step S4 is established based on peltier heat, joule heat and fourier heat conduction of thermoelectric effect, specifically: For level 1, a fitting function is used 、、 Constructing a cold-hot end heat flow equation, wherein the cold-hot end heat flow equation is shown as a formula (1), and the hot end heat flow equation is shown as a formula (2): (1) (2) for the intermediate 2 nd to i-1 th stages, a fitting function is used 、、 Constructing a cold-hot end heat flow equation, wherein the cold-hot end heat flow equation is shown as a formula (3), and the hot end heat flow equation is shown as a formula (4): (3) (4) For the ith stage, a fitting function is used 、、 Constructing a cold-hot end heat flow equation, wherein the cold-hot end heat flow equation is shown as a formula (5), and the hot end heat flow equation is shown as a formula (6): (5) (6) Wherein, the And The cold end temperature and the hot end temperature of the ith grade refrigeration component are respectively; And The heat of the cold end and the hot end of the ith grade refrigeration component are respectively represented by c, h, I and I; represents the element logarithm of the ith stage, is more than 1 and is an integer; respectively represents the electric conductivity, the Seebeck coefficient and the thermal conductivity of the bismuth telluride material; representing the i-th level element height; Representing the cross-sectional area of the i-th stage element.
10. A multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator design method as set forth in claim 1 wherein in step S5 the iterative conditions include meeting temperature continuity between adjacent layers Continuous with heat flow The iteration termination condition is that the maximum cold temperature difference is obtained Or maximum cold end heat absorption 。

Description

Multi-component bismuth telluride temperature zone adaptive multi-stage thermoelectric refrigerator design method Technical Field The application belongs to the technical field of thermoelectric device design, and particularly relates to a multi-component bismuth telluride temperature zone adaptive multi-stage thermoelectric refrigerator design method. Background The thermoelectric cooler (TEC) realizes solid-state refrigeration through direct current drive based on Peltier effect, and has the advantages of no moving parts, high reliability, compact volume and the like. To obtain a larger refrigeration temperature difference, a plurality of single-stage thermoelectric modules are commonly stacked in cascade to form a multi-stage thermoelectric refrigerator. In the multi-stage thermoelectric refrigerator structure, the cold end of the lower-stage thermoelectric module is contacted with the hot end of the higher-stage thermoelectric module to absorb heat released by the hot end of the higher-stage thermoelectric module, so that the cold end of the higher-stage thermoelectric module reaches a lower temperature, and the multi-stage thermoelectric refrigerator structure is suitable for the fields of electronic device heat dissipation, precise instrument temperature control and the like in a cryogenic environment. As the number of stages increases, a temperature gradient is formed across the interior of the multi-stage thermoelectric cooler from the cold side to the hot side. For example, when a temperature difference exceeding 100 ℃ is achieved, the cold side temperature may be as low as below-90 ℃, while the hot side temperature is still in the near room temperature range of 0-50 ℃. However, bismuth telluride-based thermoelectric materials constituting the thermoelectric cooler core have significant temperature dependence in their thermoelectric performance figure of merit (ZT value), and their key parameters such as seebeck coefficient, electrical conductivity, and thermal conductivity all vary nonlinearly with temperature. Currently, most multi-stage thermoelectric refrigerators are designed by adopting the same bismuth telluride material with single composition and performance at each stage. This results in a material that does not perform optimally in the particular local temperature region in which it is located, as it is difficult for a material to maintain the peak ZT value throughout such a wide temperature span. In addition, the existing design method is generally based on thermoelectric parameters of a single material for structural modeling, and dynamic characteristics of material performance along with temperature change cannot be fully considered, so that the performance of a device in actual work is not optimal, and refrigeration efficiency and limit temperature difference are limited. Disclosure of Invention The application provides a multi-component bismuth telluride temperature zone adaptive multi-stage thermoelectric refrigerator design method, which aims to solve the technical problem of how to realize the optimal design of the whole performance of a device through the cooperative optimization of material performance temperature zone matching and structural parameters. In order to solve at least one of the technical problems, the application adopts the following technical scheme: a multi-component bismuth telluride temperature zone adapted multi-stage thermoelectric refrigerator design method comprising the steps of: S1, preparing bismuth telluride materials with various components and different thermoelectric properties; S2, testing the change relation of thermoelectric parameters of a plurality of groups of bismuth telluride materials along with temperature in a near room temperature range; S3, screening the bismuth telluride material with the highest thermoelectric figure of merit in different temperature areas based on a test result, drawing a curve of thermoelectric parameter transformation along with temperature, and fitting the obtained high-order term expression taking the temperature as a variable; s4, setting initial values of logarithms and initial values of grain sizes of all level elements of the multi-level thermoelectric refrigerator, and substituting the fitting expression obtained in the step S3 into a thermal balance equation set of the multi-level thermoelectric refrigerator according to a temperature zone for analysis; S5, solving a heat balance equation set by iterating the logarithm and the grain size of each level element to obtain optimal design parameters, and completing the design of the multi-stage electrothermal refrigerator. Further, in the step S1, the bismuth telluride material is an N-type bismuth telluride crystal bar and a P-type bismuth telluride crystal bar prepared by a zone melting method or a hot extrusion method, wherein the compression strength is more than or equal to 80MPa. Further, for the bismuth telluride material used for preparing the N-type bis