An electrical configuration method for a multi-stage thermoelectric device for cryogenic refrigeration

Abstract

The present invention relates to an electrical configuration method for a multi-stage thermoelectric device used for cryogenic refrigeration. The multi-stage thermoelectric device is stacked in a pyramid shape, and each layer of the pyramid-shaped stack is a module at one level. An independent power supply is provided for each module at one level. The electrical configuration method is as follows: a step current is passed through step by step from the hot end to the cold end; when the current of one of the modules at one level makes the refrigeration temperature of this level of module the lowest during the stepwise increase of the current, the current magnitude at this time is set as the approximate optimized current value of this level of module. This level of module maintains its approximate optimized current value, and a step current is continued to be passed through the module at the previous level closer to the cold end, and the approximate optimized current values of all levels of modules are obtained in sequence; the approximate optimized current value of each level is passed through each level of the multi-stage thermoelectric device to complete the electrical configuration. Compared with the prior art, the present invention has the advantages of maximizing the reduction of the weakening of the refrigeration capacity of the lower-layer module caused by the heat load of the module closer to the cold end in the traditional structure, and realizing the maximization of the refrigeration capacity, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoelectric refrigeration, and in particular to an electrical configuration method for a multi-stage thermoelectric device for cryogenic refrigeration. Background Art

[0002] With the development of modern industry, there is an urgent need for more advanced refrigeration technologies to ensure the high sensitivity and thermal stability of sensing systems in low-temperature environments. Single-stage or multi-stage compression refrigeration is currently the mainstream of space refrigeration technology. However, its dependence on transmission components poses reliability risks, and the regular replenishment and replacement of refrigerants increase the maintenance costs in extreme environments.

[0003] Based on this situation, there is an urgent need to develop refrigeration technologies that supplement or replace compressors. As a fully solid-state refrigeration method, thermoelectric refrigeration technology works based on the processes of electron and hole transport, and uses the Peltier effect to convert the electrical energy of an external power supply into a temperature gradient at the cold / hot ends of the device. Its modular and compact working structure enables it to have an extremely long working life in extremely harsh environments. In addition, thermoelectric refrigeration does not require additional maintenance costs during operation, and can achieve the switching between refrigeration / heat generation and precise temperature regulation only by adjusting the polarity and magnitude of the applied current. Therefore, it has been widely applied in precision fields such as military, aerospace, and instrumentation.

[0004] However, limited by the greatly attenuated thermoelectric performance of materials at low temperatures, currently commercially available single-stage thermoelectric modules can generally only achieve a temperature difference of less than 70K, which obviously cannot meet the cryogenic refrigeration requirements. A direct way to apply thermoelectric refrigeration at low temperatures is to use a multi-stage thermoelectric device composed of cascaded single-stage modules. This thermally series structure enables further refrigeration to a lower temperature based on the cooling of the previous stages. However, each stage from the cold end to the hot end inside the multi-stage device can be regarded as an additional thermal load for the previous stage, and the refrigeration performance of the module near the hot end is greatly weakened or even fails. Therefore, multi-stage devices often cannot exert the limit of their refrigeration capacity and are still difficult to refrigerate to 180K in practical applications. Summary of the Invention

[0005] The purpose of the present invention is to overcome the defects existing in the above-mentioned prior art and provide an electrical configuration method for a multi-stage thermoelectric device for cryogenic refrigeration. A multi-stage device with a discretized electrical configuration is adopted, and its electrical configuration is optimized to effectively improve the cryogenic refrigeration performance and efficiency of the multi-stage thermoelectric device, and it is applicable to thermoelectric refrigeration applications in the low-temperature field.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] An electrical configuration method for a multi-stage thermoelectric device used for cryogenic refrigeration. The multi-stage thermoelectric device is stacked in a pyramid shape, with the hot end at the bottom and the cold end at the top. Each layer of the pyramid-shaped stack is a stage module, and an independent power supply is provided for each stage module.

[0008] The electrical configuration method is as follows: Step current is passed through the stages from the hot end to the cold end. When the current of one stage module makes the refrigeration temperature of this stage module the lowest during the stepwise increase of the current, the current magnitude at this time is set as the approximate optimized current value of this stage module. This stage module maintains its approximate optimized current value, and step current is continued to be passed to the upper stage module closer to the cold end, thereby obtaining the approximate optimized current values of all stages of modules.

[0009] The approximate optimized current value of each stage is passed into each stage of the multi-stage thermoelectric device to complete the electrical configuration.

[0010] In another example, after obtaining the approximate optimized current values of each stage of modules, the approximate optimized current value of each stage is expanded with a set step size, so that the approximate optimized current value of each stage is expanded into multiple primary selected optimized current values.

[0011] One of the primary selected optimized current values of each stage module is input, and the refrigeration temperature of the cold end of the multi-stage thermoelectric device is collected. All combinations of the primary selected optimized current values of all different stage modules are scanned and collected, and the multi-stage thermoelectric refrigeration temperatures under all combinations of the primary selected optimized current values are obtained. The combination of the primary selected optimized current values with the best refrigeration effect is obtained through fitting, and this combination of the primary selected optimized current values is the combination of the optimized current values.

[0012] The combination of the optimized current values of each stage is passed into each stage of the multi-stage thermoelectric device to complete the electrical configuration.

[0013] In another example, when expanding the approximate optimized current value of each stage with a set step size, the set step size is 0.1 - 0.5 A, and the expansion range is within ±1 A of the approximate optimized current value.

[0014] In another example, the step size of the step current is 0.1 - 0.5 A.

[0015] In another example, an electrical configuration is realized by using a discrete optimization test device. The discrete optimization test device includes a discrete current regulation module, an environment control module, and a data acquisition module. The multi-stage thermoelectric device is arranged in the environment control module. The data acquisition module is used to collect the refrigeration temperature of the multi-stage thermoelectric device, and the discrete current regulation module is used to independently supply power to each stage module.

[0016] In another example, the discrete current regulation module includes multiple independent power supplies, each independent power supply is connected to a first-level module, and under the control of a computer program, the discrete current regulation module supplies power to the multi-level module directionally with a specific current step.

[0017] In another example, the data acquisition module includes a T-type thermocouple, which is connected to the upper end of each level of module.

[0018] In another example, the environmental control module includes a water-cooled radiator and a vacuum chamber. The multi-level thermoelectric device is arranged in the vacuum chamber. The heat conduction unit of the water-cooled radiator is attached to the hot end of the multi-level thermoelectric device, and the fan of the water-cooled radiator is arranged outside the vacuum chamber.

[0019] In another example, the heat conduction unit is a high-conductivity copper block with an internal water-cooling pipeline, which is connected to the heat dissipation fins outside the vacuum chamber through a water pipe, and the fan is arranged on the heat dissipation fins.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention first analyzes and reconstructs the existing multi-level thermoelectric device in a hierarchical manner to make it have an independent power supply system for each part. This discrete electrical configuration of the multi-level thermoelectric device can give full play to the optimal refrigeration capacity of each level of module, thereby maximizing the reduction of the heat load of the module near the cold end in the traditional structure on the refrigeration capacity of the lower-level module, and realizing the maximization of the refrigeration capacity. At the same time, when performing the electrical configuration, by supplying power step by step from the hot end to the cold end, the device failure caused by excessive internal temperature is avoided, and the operation safety is improved.

[0022] 2. After obtaining the approximate optimized current value, the present invention can also perform a combined sweep test by expanding the initially selected optimized current value, so as to obtain the optimized current value combination, further ensuring the maximum refrigeration capacity of each level of module and improving the overall refrigeration effect.

[0023] 3. The present invention improves the operation convenience by setting up a discrete optimization test device, can conveniently and directly explore the optimized current values of each part under the discrete electrical configuration, can cover the real environmental factors that cannot be accurately simulated in theoretical calculations, and reveals the optimization degree of the lowest refrigeration temperature of the multi-level electrothermal device under this electrical configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow schematic diagram of the present invention.

[0025] Figure 2 It is a structural schematic diagram of the discrete optimization test device.

[0026] Figure 3Schematic diagram of approximate optimized current values at each level obtained from the step-by-step current scanning test of the Ferrotec 2040 / 470 / 060H device.

[0027] Figure 4 Schematic diagram of the multi-dimensional current scanning results by grading for the Ferrotec 2040 / 470 / 060H device.

[0028] Figure 5 Schematic diagram of the relationship between the cold-end temperature and time when the optimized current value is applied in the discrete electrical configuration / traditional series electrical configuration of the Ferrotec 2040 / 470 / 060H device.

[0029] Figure 6 Schematic diagram of the low-temperature refrigeration performance and efficiency when the optimized current value is applied in two electrical configurations of the Ferrotec 2040 / 470 / 060H device at different hot-end temperatures.

[0030] Figure 7 Schematic diagram of approximate optimized current values at each level obtained from the step-by-step current scanning test of the Star River C2405-6P2062 six-stage refrigeration device.

[0031] Figure 8 Schematic diagram of the multi-dimensional current scanning results by grading for the Star River C2405-6P2062 six-stage refrigeration device.

[0032] Figure 9 Schematic diagram of the relationship between the cold-end temperature and time when the optimized current value is applied in the discrete electrical configuration / traditional series electrical configuration of the Star River C2405-6P2062 six-stage refrigeration device.

[0033] Figure 10 Schematic diagram of the low-temperature refrigeration performance and efficiency when the optimized current value is applied in two electrical configurations of the Star River C2405-6P2062 six-stage refrigeration device.

[0034] Reference numerals: 1 - water-cooled radiator, 2 - heat conduction unit, 3 - vacuum pump, 4 - multi-stage thermoelectric device, 5 - heat compensation heating sheet, 6 - T-type thermocouple, 8 - independent power supply, 9 - computer. Detailed implementation mode

[0035] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manner and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0036] Embodiment 1

[0037] In existing multi - stage thermoelectric devices, each stage of the module is connected in an electrical series configuration. However, due to the temperature differences among the modules at each stage during operation and the differences in material properties, the current values at which each stage of the multi - stage thermoelectric device reaches the optimized state are different. Therefore, the traditional uniform series current configuration for each stage of the module cannot make each stage of the module reach the optimal state. Therefore, in this embodiment, the original electrical series structure of the multi - stage refrigeration device is analyzed to form a discrete electrical configuration for each stage, and the optimal current value for each stage of the module is explored, so that each stage of the module operates in the optimal state, and the refrigeration capacity limit of the device can be maximally exerted.

[0038] As Figure 1 shown, this embodiment provides an electrical configuration method for a multi - stage thermoelectric device for cryogenic refrigeration, which specifically includes the following:

[0039] (1) Analyze and reconstruct the configuration of the multi - stage thermoelectric device to make it a structure with electrical discreteness and thermal series, specifically: stack the multi - stage thermoelectric device in a pyramid shape, with the bottom as the hot end and the top as the cold end. Each layer of the pyramid - shaped stack is a stage of the module, and an independent power supply is set for each stage of the module.

[0040] (2) Gradually pass a stepped current with a step size of 0.5 A from the hot end to the cold end direction, and at the same time record the steady - state temperature value of the cold end of the multi - stage thermoelectric device. Record the current value when the cold end reaches the lowest steady - state temperature as the approximate optimized current value for each stage, specifically:

[0041] Gradually pass a stepped current from the hot end to the cold end; when the current of one stage of the module makes the refrigeration temperature of this stage of the module the lowest during the stepped increase process, set the current size at this time as the approximate optimized current value of this stage of the module. Keep the approximate optimized current value of this stage of the module, and continue to pass a stepped current to the next stage of the module closer to the cold end. Thus, the approximate optimized current values of all stages of the module are obtained. The step size of the stepped current is generally 0.1 - 0.5 A, and 0.5 A is preferably used in this embodiment.

[0042] (3) Within the range of ±1 A of the approximate optimized current value for each stage, perform 5 n current scans according to a specific current step size of 0.5 A. n is the number of discrete stages after electrical structure analysis. At the same time, collect the steady - state temperature of the cold end under multi - dimensional current value scans. For the results of multi - dimensional current scan tests, the optimized current values at each stage after approximation are obtained through data fitting, specifically:

[0043] After obtaining the approximate optimized current values of each level of the module, expand the approximate optimized current value of each level by a set step size, so that the approximate optimized current value of each level is expanded into multiple primary selected optimized current values. In this embodiment, the expansion range is ±1A, and the set step size is 0.5A. Therefore, one approximate optimized current value can be expanded into 5 primary selected optimized current values. Input a primary selected optimized current value of each level of the module, collect the refrigeration temperature at the cold end of the multi-stage thermoelectric device, and scan and collect by traversing all combinations of the primary selected optimized current values of all different levels of the module to obtain the multi-stage thermoelectric refrigeration temperature under all combinations of the primary selected optimized current values. The 5 primary selected optimized current values of each level have to go through permutations and combinations, that is, perform 5 n times of current scans. The combination of the primary selected optimized current values with the best refrigeration effect is obtained from the fitting result, and this combination of the primary selected optimized current values is the combination of the optimized current values.

[0044] (4) Pass the optimized current value of each level into the multi-stage thermoelectric device to complete the electrical configuration.

[0045] To implement the above electrical configuration method, this embodiment also provides a discrete optimization test device. The discrete optimization test device includes a discrete current regulation module, an environment control module, and a data acquisition module. The multi-stage electrothermal device 4 is arranged in the environment control module. The data acquisition module is used to collect the refrigeration temperature of the multi-stage electrothermal device 4, and the discrete current regulation module is used to independently supply power to each level of the module. As Figure 2 shown, the specific structure diagram of the discrete optimization test device is as follows:

[0046] The discrete current regulation module is a discrete power supply group composed of multiple independent power supplies 8. Under the control of the program of the user computer 9, it supplies power to each stage of the multi-stage electrothermal device in a specific current step size directionally. It realizes the sequential power supply to each stage of the multi-stage electrothermal device and the simultaneous power supply of multi-dimensional current values, and records and transmits the current data to the user computer 9 in real time.

[0047] The environment control module is composed of a water-cooled radiator 1 (hot-end radiator), a vacuum chamber, and a vacuum pump 3, and realizes the regulation of the test environment. The multi-stage electrothermal device 4 is arranged in the vacuum chamber. The heat conduction unit 2 of the water-cooled radiator 1 is a high-thermal-conductivity copper block with an internal water-cooling pipeline. By controlling the circulating water temperature of the water-cooled external machine, tests can be carried out at different hot-end temperatures. The vacuum degree of the test environment is controlled by the vacuum pump 3, and a vacuum test with a minimum of 1E-1Pa can be realized.

[0048] The data acquisition module uses a T-type thermocouple 6 to measure the temperature, and records the change of the cold-end temperature in real time while the current is stepped and scanned, and transmits it to the user computer 9 to realize the real-time correspondence between the current values of each level and the steady-state cold-end temperature.

[0049] A thermal compensation heating sheet 5 is also provided at the top of the multi-stage electrothermal device 4. The thermal compensation heating sheet 5 is used to assist in testing the lowest refrigeration temperature T of the multi-stage electrothermal device 4 after the electrical configuration is optimized. cmin The cooling capacity Q and the refrigeration efficiency COP at different refrigeration temperatures. The specific method is that after a period of time when a current is applied to the multi-stage electrothermal device 4 after the configuration is optimized, the device reaches a steady state, and the cold state reaches a steady-state temperature. Power is gradually supplied to the thermal compensation heating sheet 5, and the steady-state temperature of the multi-stage electrothermal device 4 changes. The heating power of the compensation heating sheet is approximately equal to the refrigeration power of the device, that is, Q = I H ×V H where I H and V H are the supply current and voltage of the compensation heating sheet. The electrical energy consumed by the device can be obtained from the product of the current and voltage of multiple power supply sources, that is, W = I1×V1 + I2×V2 +... + I n ×V n , where n is the number of stages of the device after analysis. The refrigeration efficiency can be calculated according to the ratio of the refrigeration power to the consumed electrical energy, that is, COP = Q / W.

[0050] In this embodiment, the method of gradually passing in a step current and obtaining the approximate optimized current value for each stage needs to be carried out strictly in the order from the hot end to the cold end. First, test that the single-stage module near the hot end reaches the optimized current value. On the basis of its reaching the optimized state, test the optimized current value for the single-stage module near the cold end. The step size of the step current is 0.5 A. At the same time, judge the steady-state temperature of the cold end of the multi-stage device recorded by the data acquisition module, and record the current value when the cold end reaches the lowest steady-state temperature as the approximate optimized current value.

[0051] In this embodiment, the single-stage module near the cold end can be regarded as a thermal load of the module near the hot end after being energized, which changes the optimized state of the module near the hot end. Considering the influence of the thermal load between each stage, a multi-dimensional current scan test needs to be carried out to correct the approximate optimized current value. Within the range of ±1 A of the approximate optimized value for each stage, a current scan is carried out with a current step size of 0.5 A for 5 n times, where n is the number of discretized stages after the electrical structure analysis.

[0052] In this embodiment, thermal conductive silicone grease (thermal conductivity: 6.5 W / m·K) is filled between the multi-stage electrothermal device 4 and the heat conduction unit 2, and pressure is applied to discharge the air between the two until there is an obvious resistance when the device is pushed by hand after pressurization, and the device and the water-cooled copper block will not easily undergo relative displacement under external force.

[0053] The function of the discrete optimization test device is as follows: it can fit and approximate the optimized current values at each stage of the multi-stage electrothermal device 4 based on the results of step-by-step current optimization and multi-dimensional current scanning tests; it can also test and compare the refrigeration power Q and refrigeration efficiency COP of the discretized electrical configuration and the traditional series electrical configuration when the optimized current value is applied, and test the applicable temperature range according to the existing optimized configuration, which is more practical and economical.

[0054] Example Two

[0055] Select a 2040 / 470 / 060H commercial four-stage refrigeration device produced by Ferrotec Corporation. Refer to Figure 2 As shown, the operating steps for the electrical configuration are as follows:

[0056] (1) Analyze and reconstruct the configuration of the multi-stage thermoelectric device 4 to make it a structure with electrical discretization and thermal series connection as a whole.

[0057] (2) Install the multi-stage electrothermal device 4 on the heat conduction unit 2 with an internal water cooling pipeline, and connect the power leads of each part after analysis to multiple independent power supplies 8 respectively.

[0058] (3) Apply a step current with a step size of 0.5 A step by step in the direction from the hot end to the cold end, and record the cold-end steady-state temperature value collected by the data acquisition module at the same time. Denote the current value when the cold end reaches the lowest steady-state temperature as the approximate optimized current value for each stage.

[0059] (4) Within the range of ±1 A of the approximate optimized current value for each stage, perform 5 n current scans according to a specific current step size of 0.5 A. n is the number of levels of discretization after the electrical structure analysis, and at the same time, collect the cold-end steady-state temperature under multi-dimensional current value scans.

[0060] (5) For the results of the multi-dimensional current scanning test, obtain the approximated optimal current value combination through data fitting.

[0061] (6) Apply the optimized current value to each stage of the multi-stage thermoelectric device 4 to complete the electrical configuration.

[0062] In this embodiment, the connection between two levels of the multi-stage electrothermal device is made by a conductive metal in the through hole of the ceramic plate. The analysis and reconstruction method in step (1) is as follows: use a hacksaw to cut the copper strip plated on the ceramic substrate. Due to the actual reasons of the device structure, the two levels closest to the cold end of the device are not analyzed. Therefore, this four-stage device is analyzed into three parts. Weld an extremely short wire to the conductive copper strips on the left and right parts of each stage module to achieve the electrical series connection of the thermoelectric couples in the single-stage module.

[0063] Figure 3The approximate optimized current values at each level obtained from the step-by-step current scanning test of the Ferrotec 2040 / 470 / 060H device are successively I aopt1 = 9.0 A, I aopt2 = 5.0 A, I aopt3 = 4.0 A. The upper stages close to the heat source can all be regarded as the heat load of the lower stage, and under the influence of the heat load, the optimized current conditions of each stage will change to a small extent. Figure 4 It is the result of the hierarchical multi-dimensional current scanning of the Ferrotec 2040 / 470 / 060H device. Among the 125 data points obtained from the three-dimensional current value scanning, the optimized values deduced by data fitting are I opt1 = 10.0 A, I opt2 = 5.0 A, I opt3 = 4.1 A. Compared with the uniform current configuration obtained by series connection of each stage, the optimized current value of the hot-end device under the discrete electrical configuration increases significantly. This shows that the multi-stage thermoelectric device 4 under the independent current configuration mainly realizes the improvement of the overall refrigeration capacity by enhancing the refrigeration capacity of the module close to the hot end.

[0064] Figure 5 It is the relationship between the cold-end temperature and time when the optimized current value is applied to the Ferrotec 2040 / 470 / 060H device under the discrete electrical configuration / traditional series electrical configuration. The multi-stage device under the discrete electrical configuration reduces the lowest refrigeration temperature by 9.2 K compared with the traditional series electrical configuration, and at the same time, the time to reach the lowest refrigeration temperature under the series configuration is shortened by nearly half, which reflects the superiority of the refrigeration capacity and refrigeration speed of the device with the independent optimized current configuration. Figure 6 It is the low-temperature refrigeration performance and efficiency of the Ferrotec 2040 / 470 / 060H device in two electrical configurations at different hot-end temperatures. Comparing the two circuit configurations, there are performance critical points in the low-temperature field (T h = 284 K, T cross = 196 K; T h = 298 K, T cross = 204 K). For refrigeration applications below this critical temperature, this multi-stage electro-thermal device 4 with a discrete electrical configuration has significant refrigeration performance and efficiency superiority.

[0065] Example 3

[0066] Select the C2405-6P2062 commercial six-stage refrigeration device produced by Xinghe Company. Referring to Figure 2 as shown, the operation steps for the electrical configuration are as follows:

[0067] (1) Analyze and reconstruct the configuration of the multi-stage thermoelectric device 4 to make it a structure with discrete electricity and series heat.

[0068] (2) Install the multi - stage electrothermal device 4 on the heat - conducting unit 2 with an internal water - cooling pipeline, and connect the power leads of each part after dissection to multiple independent power supplies 8 respectively.

[0069] (3) Gradually pass a step - by - step current with a step size of 0.5 A from the hot end to the cold end, and simultaneously record the steady - state temperature value of the cold end collected by the data acquisition module. Denote the current value when the cold end reaches the lowest steady - state temperature as the approximate optimized current value for each level.

[0070] (4) Within the range of ±1 A of the approximate optimized current value for each level, perform 5 n current scans according to a specific current step size of 0.5 A. n is the number of discretized levels after the dissection of the electrical structure. At the same time, collect the steady - state temperature of the cold end under multi - dimensional current value scans.

[0071] (5) For the results of the multi - dimensional current scan test, obtain the combined optimized current value after approximation through data fitting.

[0072] (6) Pass the optimized current value for each level into each level of the multi - stage thermoelectric device 4 to complete the electrical configuration.

[0073] In this embodiment, for the multi - stage device with solder - connected conductive copper bars between two levels, the dissection and reconstruction method in step (1) is as follows: Remove the solder between the two - level conductive copper bars by desoldering and solder sucking. According to the structure of this device, dissect it into six parts. At the same time, weld an extremely short wire on the conductive copper bars of the left and right parts of each level module to realize the electrical series connection of the thermoelectric couples in this single - level module.

[0074] Figure 7 The approximate optimized current values obtained from the step - by - step current scan test for each level of the Xinghe C2405 - 6P2062 six - stage refrigeration device are, in sequence, I aopt1 = 9.0 A, I aopt2 = 4.0 A, I aopt3 = 3.0 A, I aopt4 = 3.0 A, I aopt5 = 3.5 A, I aopt6 = 3.5 A. From the change of the cold - end temperature with the step - by - step current, it can be seen that the approximate optimized current values of the four levels near the cold end are similar, and the change of the cold - end temperature of the device near the optimized current value is not sensitive. According to the results of this step - by - step experiment, it is more efficient to dissect the electrical structure of this multi - stage device into three parts, namely the first level near the hot end, the second level, and the third to sixth levels near the cold end.

[0075] Figure 8 For the multi - level current scan results of the Xinghe C2405 - 6P2062 six - stage refrigeration device, among the 125 data points obtained from the three - dimensional current value scan, the optimized value is deduced to be Iopt1 =9.4A, I opt2 =4.2A,I opt3 =3.2A. Figure 9 It can be seen that under the same optimized state, the lowest cooling temperature under the discrete electrical configuration is 10.2K lower than that under the traditional series electrical configuration. Figure 10 The low-temperature refrigeration performance and efficiency of the two electrical configurations also reveal the significant advantages of this discrete electrical configuration below 200K.

[0076] In summary, the technical solution of the present invention has the following advantages:

[0077] 1. When it is unavoidable that the heat load near the cold-end module weakens the cooling capacity of the lower modules, the discrete electrical configuration of this multi-stage thermoelectric device can better exert the optimal cooling capacity of each level of module and maximize the cooling capacity.

[0078] Second, this technical solution can conveniently and directly explore the optimized current value of each part under the discrete electrical configuration, which can cover the real environmental factors that cannot be accurately simulated in theoretical calculations, and reveals the optimization degree of the minimum cooling temperature of the multi-stage electric heating device under this electrical configuration.

[0079] 3. In the low temperature range, the cooling capacity and cooling efficiency of the multi-stage electric heating device under the discrete electrical configuration are significantly superior to the values under the traditional series electrical configuration, proving the advanced nature of this electrical configuration in the field of low-temperature refrigeration.

[0080] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. An electrical configuration method for a multi-stage thermoelectric device used for cryogenic refrigeration, characterized in that: The multi-stage thermoelectric device is stacked in a pyramid shape, with the lower end being the hot end and the upper end being the cold end. Each layer of the pyramid-shaped stack is a stage module, and an independent power supply is set for each stage module; The electrical configuration method is as follows: Step current is passed through from the hot end to the cold end in sequence; when the current of one of the stage modules makes the refrigeration temperature of this stage module the lowest during the stepwise increase of the current, the current magnitude at this time is set as the approximate optimized current value of this stage module. This stage module maintains its approximate optimized current value, and step current is continued to be passed into the upper stage module closer to the cold end, and the approximate optimized current values of all stages of modules are obtained in sequence; Pass the approximate optimized current value of each stage into the multi-stage thermoelectric device to complete the electrical configuration; After obtaining the approximate optimized current values of each stage of modules, expand the approximate optimized current value of each stage by a set step size, so that the approximate optimized current value of each stage is expanded into multiple primary selected optimized current values; Input a primary selected optimized current value of each stage of module, collect the refrigeration temperature of the cold end of the multi-stage thermoelectric device, scan and collect all combinations of primary selected optimized current values of all different stage modules, obtain the multi-stage thermoelectric refrigeration temperature under all combinations of primary selected optimized current values, and fit the temperature results to obtain the combination of primary selected optimized current values with the best refrigeration effect. This combination of primary selected optimized current values is the combination of optimized current values; Pass the optimized current value of each stage into the multi-stage thermoelectric device to complete the electrical configuration.

2. The electrical configuration method of a multi-stage thermoelectric device for cryogenic refrigeration according to claim 1, wherein When expanding the approximate optimized current value of each stage by a set step size, the set step size is 0.1 - 0.5 A, and the expansion range is within ±1 A of the approximate optimized current value.

3. The electrical configuration method of a multi-stage thermoelectric device for cryogenic refrigeration according to claim 1, characterized in that, The step size of the step current is 0.1 - 0.5 A.

4. The electrical configuration method of a multi-stage thermoelectric device for cryogenic refrigeration according to claim 1, characterized in that, An electrical configuration is carried out by using a discrete optimization test device. The discrete optimization test device includes a discrete current regulation module, an environment control module, and a data acquisition module. The multi-stage thermoelectric device is arranged in the environment control module. The data acquisition module is used to collect the refrigeration temperature of the multi-stage thermoelectric device, and the discrete current regulation module is used to independently supply power to each stage module.

5. The electrical configuration method of a multi-stage thermoelectric device for cryogenic refrigeration according to claim 4, characterized in that, The discrete current regulation module includes multiple independent power supplies, and each independent power supply is connected to a stage module. Under the control of a computer program, the discrete current regulation module supplies power to the multi-stage module directionally with a specific current step size.

6. The electrical configuration method of a multi-stage thermoelectric device for cryogenic refrigeration according to claim 4, characterized in that, The data acquisition module includes a T-type thermocouple, which is connected to the upper end of each stage module.

7. A method for electrically configuring a multi-stage thermoelectric device for cryogenic refrigeration according to claim 4, characterized in that, The environment control module includes a water-cooled radiator and a vacuum chamber. The multi-stage thermoelectric device is arranged in the vacuum chamber. The heat conduction unit of the water-cooled radiator is attached to the hot end of the multi-stage thermoelectric device, and the fan of the water-cooled radiator is arranged outside the vacuum chamber.

8. A method for electrically configuring a multi-stage thermoelectric device for cryogenic refrigeration according to claim 7, characterized in that, The heat conduction unit is a high-conductivity copper block with an internal water-cooling pipeline, which is connected to the heat dissipation fins located outside the vacuum chamber through a water pipe, and the fan is arranged on the heat dissipation fins.

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