CN103323284A - Thermoelectric refrigeration performance measuring device and method - Google Patents

Abstract

The invention relates to a thermoelectric refrigeration performance measurement device and method thereof. A thermoelectric refrigeration module, a closed space and a water-cooled radiator are placed in a vacuum cavity, a section of electric heating wire is placed in the closed space, and the heat load is simulated, and the water-cooled radiator is used to control the thermoelectric refrigeration. The temperature of the hot end of the module, the thermoelectric refrigeration module is located between the closed space as the cold end unit and the water-cooled radiator as the hot end unit, the cold end thermocouple is placed on the contact surface between the airtight space and the thermoelectric refrigeration module, and the hot end thermocouple is placed On the contact surface between the water-cooled radiator and the thermoelectric refrigeration module, the cold-end thermocouple and the hot-end thermocouple collect the working temperature of the cold and hot ends and send them to the data acquisition instrument, and the digital power meter collects the operating voltage, operating current, thermoelectric potential and The power of the heating wire, the computer receives and analyzes the data collected by the data acquisition instrument and the digital power meter. The structure of the device is compact and reasonable, the test is simple and the test accuracy is high.

Description

A thermoelectric refrigeration performance measuring device and method thereof

technical field

The invention relates to a refrigeration technology, in particular to a thermoelectric refrigeration performance measuring device and a method thereof.

Background technique

With the aggravation of energy crisis and environmental problems, thermoelectric refrigeration based on thermoelectric effect has attracted more and more attention due to its outstanding characteristics. Compared with other refrigeration methods, thermoelectric refrigeration has unique advantages such as no mechanical moving parts, no compressor, no refrigerant, compact structure, no noise, no pollution, and long service life. It is widely used in military, aerospace, Energy, microelectronics, optoelectronic devices and other equipment and industrial and commercial products. At present, the biggest problem facing the practical application of thermoelectric refrigeration is that the cooling capacity of the thermoelectric refrigeration module is small, and it is difficult to evaluate the performance of the thermoelectric module. The performance is closely related to the quality of the refrigeration device.

Important parameters to measure the performance of thermoelectric refrigeration include cooling capacity Q, cooling coefficient COP, and figure of merit Z. Traditional methods often calculate the values of the above three parameters based on theoretical formulas. In the calculation process, the values of Seebeck coefficient α, total resistance R and total thermal conductivity K are based on the theoretical experimental values provided by the thermoelectric module manufacturer, ignoring the Seebeck coefficient and total resistance caused by the change of the working environment of the thermoelectric module in actual use. and the change of the total thermal conductance, so this calculation method cannot accurately calculate the cooling capacity, cooling coefficient and figure of merit of the thermoelectric module. However, there are relatively few data on the Seebeck coefficient, total resistance and total thermal conductivity of thermoelectric modules under different application conditions, and are limited to several commonly used types of thermoelectric modules. In actual application conditions, although there are many measurement methods for the Seebeck coefficient, total resistance and total thermal conductivity of thermoelectric modules, the existing test methods have problems such as complex structure of the test device, long test process, and low test accuracy. , especially for the measurement of thermoelectric modules already in use, most of the test methods are hardly operable.

Contents of the invention

The present invention aims at the problems of complex structure and inconvenient testing process of existing thermoelectric refrigeration performance measurement devices, and proposes a thermoelectric refrigeration performance measurement device and its method, which are used to measure the cooling capacity Q and refrigeration coefficient COP of thermoelectric modules under actual application conditions. , thermoelectric figure of merit Z and other thermodynamic performance measurements. The device has the advantages of small size, low cost, simple and convenient testing process and method, and accurate results.

The technical solution of the present invention is: a thermoelectric refrigeration performance measurement device, including a thermoelectric refrigeration module to be tested, a closed space, an electric heating wire, a water-cooled radiator, a cold-end thermocouple, a hot-end thermocouple, a data acquisition instrument, a digital power meter, Computer, vacuum chamber, vacuum pump; thermoelectric refrigeration module, closed space and water-cooled radiator are placed in the vacuum chamber, a section of electric heating wire is placed in the closed space, and the thermoelectric refrigeration module is located in the closed space as the cold end unit and the water-cooled heat dissipation unit as the hot end unit Between the radiators, the cold-end thermocouple is placed on the contact surface between the closed space and the thermoelectric refrigeration module, and the hot-end thermocouple is placed on the contact surface between the water-cooled radiator and the thermoelectric refrigeration module. The cold-end thermocouple and the hot-end thermocouple collect cold and heat. The working temperature at the end is sent to the data acquisition instrument, and the digital power meter collects the working voltage, current, thermoelectric potential and heating wire power of the thermoelectric refrigeration module respectively, and the computer receives and analyzes the data collected by the data acquisition instrument and the digital power meter.

A method for measuring thermoelectric refrigeration performance, including a thermoelectric refrigeration performance measurement device, specifically includes the following steps:

1) Turn on the vacuum pump and control the vacuum degree of the system to below 10 ^-3 Pa;

2) According to the performance parameter table provided by the manufacturer, adjust the working voltage _of the thermoelectric module under test to find ^the maximum temperature difference working condition. Temperature T _H ^' , the digital power meter records the operating voltage V _max , operating current I _max and thermoelectric potential E _max at this time, and inputs all data into the computer for storage, calculation and display;

3) According to the measured temperature T _H ^' and voltage V _max of the hot end surface of the thermoelectric module, the computer calculates the Seebeck coefficient α of the thermoelectric refrigeration module;

4) According to the measured operating voltage V _max , current I _max and thermoelectric potential value E _max of the thermoelectric module, the computer calculates the total resistance R of the thermoelectric refrigeration module;

5) According to the measured thermoelectric module operating voltage V _max , current I _max , thermoelectric potential value E _max and hot end surface temperature T _H ^' , the computer calculates the total thermal conductivity K of the thermoelectric cooling module;

6) Adjust the power supply voltage of the thermoelectric refrigeration module, adjust the heating power of the heating wire at the same time, and load a heat load on the cold end of the module. After the test system is stable, the data acquisition instrument collects the cold end work through the cold end thermocouple and the hot end thermocouple. Temperature T _C and hot end working temperature T _H , the digital power meter records the working voltage V, working current I and thermoelectromotive force E at this time, and enters all data into the computer for storage and processing;

7) According to the calculated α, R, K and the measured I, T _H , T _C , the computer calculates the cooling capacity Q , the consumed electric power P , the cooling coefficient COP, and the thermoelectric figure of merit Z to complete the performance measurement;

8) Measurement of thermoelectric module performance at different hot end temperatures: change the cooling water temperature through the water-cooled radiator to change the hot end temperature of the thermoelectric cooling module, repeat steps 1) to 7) to complete the performance of the thermoelectric cooling module at different hot end temperatures Measurement.

The beneficial effect of the present invention is that: the thermoelectric refrigeration performance measuring device and the method thereof of the present invention have a compact and reasonable structure, simple and convenient testing, and high testing precision.

Description of drawings

Fig. 1 is a schematic structural diagram of a thermoelectric refrigeration performance measuring device of the present invention;

Fig. 2 is a schematic diagram of the electrical parameter measurement of the thermoelectric cooling performance measuring device of the present invention.

Detailed ways

As shown in Figure 1, the structural diagram of the thermoelectric cooling performance measurement device includes the tested thermoelectric cooling module 1, the confined space 2, the heating wire 3, the water cooling radiator 4, the cold end thermocouple 5, the hot end thermocouple 6, and the data acquisition instrument 7 , a digital power meter 8, a computer 9, a vacuum device, the vacuum device includes a vacuum chamber 10 and a vacuum pump 11. The thermoelectric refrigeration module 1, the closed space 2 and the water-cooled radiator 4 are placed in the vacuum chamber 10, the cold end unit is a closed space 2, and a section of heating wire 3 is placed in the space to simulate the thermal load, and the heating power of the heating wire can be adjusted Simulate a variable load; the hot end unit is a water-cooled radiator 4, which is used to control the temperature of the hot end of the thermoelectric refrigeration module 1; the thermoelectric refrigeration module 1 is located between the enclosed space 2 and the water-cooled radiator 4, and the cold-end thermocouple 5 is placed in the enclosed space 2 On the contact surface with the thermoelectric refrigeration module 1, the hot end thermocouple 6 is placed on the contact surface between the water-cooled radiator 4 and the thermoelectric refrigeration module 1.

The data acquisition and processing unit includes a cold-end thermocouple 5 and a hot-end thermocouple 6 , a data acquisition instrument 7 , a digital power meter 8 and a computer 9 . The thermocouple collects the working temperature of the cold end and the hot end and sends it to the data acquisition instrument 7; the digital power meter 8 collects the operating voltage and operating current of the thermoelectric refrigeration module 1, the thermoelectric potential, and the power of the heating wire 3; the computer 9 receives the data acquisition instrument 7 and The data collected by the digital power meter 8 is analyzed and processed.

The vacuum device includes a vacuum chamber 10 and a vacuum pump 11, which are used to control the vacuum degree of the system to below 10 ^-3 Pa, so the influence of air convection heat transfer can be ignored.

During the test experiment, the measurement principle of several working electrical parameters of the thermoelectric refrigeration module 1 is shown in Fig. 2 . Channel 1 measures the operating voltage, channel 2 measures the operating current, and channel 3 measures the thermoelectric potential. After the test system reaches stability, record the working voltage and current value at this time, toggle the transfer switch, cut off the power supply of the thermoelectric refrigeration module 1, and connect the measurement channel of the thermoelectric electromotive force. In order to eliminate switching noise and obtain a good sampling signal, the temperature difference The measurement of the electromotive force requires a short delay (t=0.5s), so that the thermoelectric module's thermoelectric electromotive force value can be obtained.

The specific steps and methods can be operated according to the following requirements:

1) Turn on the vacuum pump 11 and control the vacuum degree of the system to below 10 ^-3 Pa.

2) According to the performance parameter table provided by the manufacturer, adjust the operating voltage of the thermoelectric module 1 under test, find the maximum temperature difference working condition, use the cold end thermocouple 5 to measure the working temperature T _C ^' of the cold end, and the hot end thermocouple 6 to measure the working temperature of the hot end Temperature T _H ^' , collect temperature signals T _C ^' and T _H ^' with data acquisition instrument 7, use digital power meter 8 to record operating voltage V _max , operating current I _max and thermoelectromotive force E _max at this time, and input all data into the computer 9 storage, calculation and display.

3) Calculate the Seebeck coefficient α of the thermoelectric module by using the computer 9 according to the measured temperature T _H ^' and voltage V _max of the hot end surface of the thermoelectric module;

4) Calculate the total resistance R of the thermoelectric module by using the computer 9 according to the measured working voltage V _max , current I _max and thermoelectric potential value E _max of the thermoelectric module;

5) Calculate the total thermal conductance K of the thermoelectric module by using the computer 9 according to the measured operating voltage V _max , current I _max , thermoelectric potential value E _max and hot end surface temperature T _H ^' of the thermoelectric module;

6) Adjust the power supply voltage of the thermoelectric module 1, and adjust the heating power of the heating wire 3 at the same time, and load a heat load on the cold end of the module. After the test system reaches stability, use the cold end thermocouple 5 to measure the working temperature T _C of the cold end, and The thermocouple 6 measures the working temperature T _H of the hot end, collects the temperature signals T _C and T _H with the data acquisition instrument 7, uses the digital power meter 8 to record the working voltage V, the working current I and the thermoelectromotive force E at this time, and inputs all the data Computer 9 saves and processes.

7) According to the calculated α, R, K and the measured I, T _H , T _C , the computer 9 can be used to calculate the cooling capacity Q , the consumed electric power P , the cooling coefficient COP, and the thermoelectric figure of merit Z to complete the performance measurement .

8) Measurement of the performance of the thermoelectric module at different hot end temperatures: changing the temperature of the cooling water passing through the water-cooled radiator 4 can change the temperature of the hot end of the thermoelectric cooling module. Repeat the above steps to complete the performance measurement of the thermoelectric cooling module at different hot end temperatures.

Claims (2)

1. a thermoelectric cooling device for measuring properties, is characterized in that, comprises tested thermoelectric refrigerating module (1), confined space (2), heating wire (3), water-filled radiator (4), cold junction thermopair (5), hot junction thermopair (6), data collecting instrument (7), digital power meter (8), computing machine (9), vacuum chamber (10), vacuum pump (11), thermoelectric refrigerating module (1), confined space (2) and water-filled radiator (4) are placed in vacuum chamber (10), place one section heating wire (3) in confined space (2), thermoelectric refrigerating module (1) is positioned at as between the confined space (2) of cold junction unit and the water-filled radiator (4) as the unit, hot junction, cold junction thermopair (5) is placed on confined space (2) and thermoelectric refrigerating module (1) surface of contact, hot junction thermopair (6) is placed on water-filled radiator (4) and thermoelectric refrigerating module (1) surface of contact, cold junction thermopair (5) and hot junction thermopair (6) gather cold, the working temperature in hot junction is sent data collecting instrument (7), digital power meter (8) gathers respectively the operating voltage of thermoelectric refrigerating module (1), working current, thermoelectromotive force and heating wire (3) power, computing machine (9) receives the data of data collecting instrument (7) and digital power meter (8) collection and carries out analyzing and processing.

2. a thermoelectric cooling performance measurement method, comprise the thermoelectric cooling device for measuring properties, it is characterized in that, specifically comprises the steps:

1) open vacuum pump (11), control system vacuum tightness to 10 ^-3below Pa;

2) the performance parameter table provided according to producer, the operating voltage of regulating tested electrothermal module (1), find the maximum temperature difference operating mode, and data collecting instrument (7) gathers the cold junction work temperature by cold junction thermopair (5) and hot junction thermopair (6) _c ^'with the hot junction work temperature _h ^', digital power meter (8) record operating voltage V now _max, working current I _maxwith thermoelectromotive force E _max, by all data input computing machines (9) storage, calculating and demonstration;

The temperature T of the electrothermal module hot junction face that 3) basis measures _h ^'with voltage V _max, computing machine (9) calculates the Seebeck coefficient α of thermoelectric refrigerating module (1);

4) according to the electrothermal module operating voltage V measured _max, electric current I _maxand thermoelectromotive force value E _max, computing machine (9) calculates the all-in resistance R of thermoelectric refrigerating module (1);

5) according to the electrothermal module operating voltage V measured _max, electric current I _max, thermoelectromotive force value E _maxand hot junction surface temperature T _h ^', computing machine (9) calculates the overall thermal conductance K of thermoelectric refrigerating module (1);

6) adjust the supply voltage of thermoelectric refrigerating module (1), regulate heating wire (3) heating power simultaneously, load a thermal load to the module cold junction, after system to be tested reaches and stablizes, data collecting instrument (7) gathers the cold junction work temperature by cold junction thermopair (5) and hot junction thermopair (6) _cwith the hot junction work temperature _h, digital power meter (8) record operating voltage V now, working current I and thermoelectromotive force E, preserve all data input computing machines (9), process;

7) according to calculating gained α, R, K and measuring gained I, T _h, T _c, computing machine (9) calculates refrigerating capacity q, the electric power of consumption p, coefficient of performance, thermoelectric figure of merit coefficient z, complete performance measurement;

8) measurement of electrothermal module performance under different hot-side temperatures: the cooling water temperature changed by water-filled radiator (4) changes the thermoelectric refrigerating module hot-side temperature, repeats 1)～7) step, the performance measurement of thermoelectric refrigerating module under different hot-side temperatures completed.

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