TWI467407B - Method of computing coefficient of performance, refrigerating capacity and error of thermoelectric cooling chip - Google Patents

Description

Method for calculating coefficient of performance, actual cooling capacity and experimental error of thermoelectric wafer in a system

The present disclosure relates to methods of computing by computer, and more particularly to a method of using computer hardware and software to fit data related to thermoelectric wafers in a computing system.

At present, a coefficient of performance (COP) method for a thermoelectric wafer to be used in a system, such as a thermoelectric cooling system of the prior art, is to calculate the energy of the hot and cold end of the thermoelectric chip by calculating the fluid in the water-cooled heat sink. To obtain the thermoelectric chip performance coefficient (COP); the foregoing method must calculate the coefficient of performance (COP) of the thermoelectric wafer through a complicated operation method.

In another example, the thermoelectric cooling system of the prior art published in international academic journals calculates the coefficient of performance after experimentally measuring the thermoelectric parameters. First, the hot and cold ends of the thermoelectric wafer are respectively contacted on the surface of the metal block, and two A temperature thermocouple wire is pre-embedded in the metal block. In addition, in addition to measuring the temperature of the hot and cold end of the thermoelectric chip, a heater is placed on the other end of the thermoelectric chip in contact with the metal block, and the heater and the thermoelectric chip are placed. When the cold end reaches the thermal equilibrium, the thermoelectric chip cooling power can be reversed from the power applied by the heater; however, the foregoing method requires relevant experiments in a vacuum environment to avoid heat loss and external intrusion heat.

The above-mentioned conventional techniques often require measurement and calculation by more complicated experimental methods and more sophisticated instruments, which not only causes inconvenience in practical operation and application, but also has a problem of high cost of measuring equipment.

Therefore, one technical aspect of the present disclosure is to provide a method for calculating a coefficient of thermal power chip performance, an actual cooling capacity, and an experimental error in a system to overcome the above-mentioned practical operation, inconvenient application, and high cost of the measuring device.

According to an embodiment of the present invention, a method for calculating a coefficient of performance of a thermoelectric chip in a system is provided, which is performed by means of a computer, comprising the steps of: recording a plurality of voltages when a thermoelectric chip is mounted in the system by using a recording unit; (V _i ), a plurality of currents (I _i ), a plurality of hot end temperatures (T _Hi ), and a plurality of cold junction temperatures (T _Ci ). Using a calculation unit, the voltage (V _i ), the current (I _i ), the hot end temperature (T _Hi ), and the cold junction temperature (T _Ci ) are substituted into a first equation V _i =α( T _Hi - T _Ci )+ I _i R , the solution to the cubic equation gives a Becker coefficient (α) and an internal resistance (R). Input a fixed voltage (V) to the thermoelectric chip, and measure a current (I), a hot end temperature (T _H ), a cold end temperature (T _C ), and a cold and hot end of the thermoelectric chip by a measuring unit. Temperature difference (ΔT). A query unit is used to query a basic performance graph of the thermoelectric chip, and the uniform cooling capacity (Q _C ) of the thermoelectric chip is obtained. The calculation unit is used to substitute the Schübeck coefficient (α), current (I), cold junction temperature (T _C ), internal resistance (R) and hot and cold end temperature difference (ΔT) into a second equation. , a heat transfer coefficient (K) is obtained. Substituting the Sibeck coefficient (α), internal resistance (R) and heat transfer coefficient (K) into a third-party program using a calculation unit , get a high quality coefficient (Z). The calculation unit is used to substitute the Sibeck coefficient (α), current (I), cold junction temperature (T _C ), internal resistance (R), heat transfer coefficient (K) and hot and cold end temperature difference (ΔT) into a fourth equation. , to obtain an actual cooling capacity (Q _CR ). The calculation unit is used to substitute the Scheib coefficient (α), current (I), hot end temperature (T _H ), cold junction temperature (T _C ) and internal resistance (R) into a fifth equation P = α I ( T _H - T _C ) + I ² R , to obtain an input power (P). Substituting the actual cooling capacity (Q _CR ) and input power (P) into a sixth equation using a computing unit To obtain a thermoelectric wafer coefficient of performance (COP) in a system.

Further, in other embodiments of the technical aspect, the computing unit may further comprise a seventh equation. The step of calculating an experimental error is calculated. After the foregoing steps are completed, data with an experimental error of less than 10% is output and plotted by a drawing unit. In addition, it is also possible to determine whether the Schiebeck coefficient (α), the internal resistance value (R), and the heat transfer coefficient (K) are correct by repeating the first five steps by a verification unit.

According to another embodiment of the present technology, a method for calculating the actual cooling capacity of a thermoelectric chip in a system is provided, which is performed by a computer, and includes the following steps: using a plurality of voltages when a thermoelectric chip is mounted in the system ( V _i ), a plurality of currents (I _i ), a plurality of hot end temperatures (T _Hi ), and a plurality of cold junction temperatures (T _Ci ), and a Becker coefficient (α) and an internal resistance value are obtained via a calculation unit ( R). Inputting a fixed voltage (V) to the thermoelectric chip, and measuring a current (I), a hot end temperature (T _H ), a cold end temperature (T _C ), and a heat of the thermoelectric chip by a measuring unit End temperature difference (ΔT). A query unit is used to query a basic performance graph of the thermoelectric chip, and the uniform cooling capacity (Q _C ) of the thermoelectric chip is obtained. A heat transfer coefficient (K) is obtained via a calculation unit using the Schiebeck coefficient (α), the current (I), the cold junction temperature (T _C ), the internal resistance value (R), and the hot and cold end temperature difference (ΔT). Using the Sibeck coefficient (α), the internal resistance (R), and the heat transfer coefficient (K), a high-quality coefficient (Z) is obtained via the calculation unit. The calculation unit is used to substitute the Sibeck coefficient (α), current (I), cold junction temperature (T _C ), internal resistance (R), heat transfer coefficient (K) and hot and cold end temperature difference (ΔT) into the equation. , to obtain an actual cooling capacity (Q _CR ).

Furthermore, in other embodiments of the present technical aspect, the computing unit can substitute the voltage (V _i ), the current (I _i ), the hot end temperature (T _Hi ), and the cold junction temperature (T _Ci ) into the equation. V _i =α( T _Hi - T _Ci )+ I _i R , and the Sibeck coefficient (α) and the internal resistance value (R) are obtained after the solution is combined. Furthermore, the calculation unit can also substitute the Schiesbeck coefficient (α), the current (I), the cold junction temperature (T _C ), the internal resistance value (R), and the hot and cold end temperature difference (ΔT) into the equation. , the heat transfer coefficient (K) is obtained. On the other hand, the calculation unit can substitute the Schiesbeck coefficient (α), internal resistance (R) and heat transfer coefficient (K) into the equation. , get the quality coefficient (Z).

According to still another embodiment of the present technical aspect, a method for calculating an experimental error of a thermoelectric chip performance coefficient in a system by using the actual cooling capability of the foregoing method is proposed, which is performed by a computer, and includes the following steps: using the Scheben coefficient ( α), current (I), hot end temperature (T _H ), cold junction temperature (T _C ), and internal resistance (R) determine an input power (P) via a calculation unit. Substituting actual cooling capacity (Q _CR ) and input power (P) into the equation via the calculation unit To obtain a thermoelectric wafer coefficient of performance (COP) in a system. Computing unit using equations Calculate an experimental error.

Further, in other embodiments of the technical aspect, the method further includes outputting an experimental error of less than 10%, and drawing a mapping step by using a drawing unit.

Therefore, the above embodiments can not only quickly calculate the coefficient of performance of the thermoelectric wafer applied to the system, but also save the cost of the conventional technique due to the measurement method.

1 is a system diagram of a method for calculating a coefficient of performance of a thermoelectric wafer in a computing system according to an embodiment of the present disclosure, and FIG. 2 is a partially enlarged view showing a method for determining a coefficient of performance of a thermoelectric wafer in the computing system of FIG. 1. As shown in FIG. 1 and FIG. 2, the present embodiment describes a subsequent calculation method by a simple cooling system 100. First, the cooling system 100 of the present embodiment includes a case 110, a thermoelectric chip 120, and a The power supply 130, the two metal heat conducting blocks 140, a flat fin 150, a heat sink 160, two thermocouple temperature sensors 170, a paperless multipoint recorder 180, and a computer 190.

The thermoelectric wafer 120 is mounted on the casing 110, and the thermoelectric wafer 120 has a cold end 121 and a hot end 122. The power supply 130 supplies a direct current voltage to the thermoelectric wafer 120, causing the thermoelectric wafer 120 to generate a hot and cold phenomenon. The two metal heat conducting blocks 140 are respectively adhered to the cold end 121 and the hot end 122 of the thermoelectric wafer 120, and the two metal heat conducting blocks 140 each have a groove 141. The flat fins 150 are located within the housing 110 and are coupled to the metal thermal block 140 of the cold end 121. The heat sink 160 is coupled to the metal heat transfer block 140 of the hot end 122. The two thermocouple temperature sensors 170 are respectively located in the trenches 141 of the two metal heat conducting blocks 140 for sensing the temperature conditions of the cold end 121 and the hot end 122 of the thermoelectric chip 120. The paperless multi-point recorder 180 is connected to the two thermocouple temperature sensors 170 for receiving the temperature data of the thermocouple wafer 120 cold 121 and the hot end 122 of the two thermocouple temperature sensors 170. The computer 190 is coupled to the paperless multipoint recorder 180 for recording temperature data received by the paperless multipoint recorder 180.

It is worth mentioning that the two metal thermal block 140 is bonded to the cold end 121 and the hot end 122 of the thermoelectric chip 120 by a thermal grease. In addition, the gap between the trench 141 and the thermocouple temperature sensor 170 is also filled with a thermal paste.

3A to 3C are flow charts showing the steps of the method for calculating the coefficient of performance of the thermoelectric chip in the computing system of Fig. 1, wherein the contents of Figs. 3A and 3B are successive. The steps of the method 200 of calculating the coefficient of performance of the thermoelectric wafer in a particular system will be described in detail later.

Step 210 is to record, by using a recording unit, a plurality of voltages (V _i ), a plurality of currents (I _i ), a plurality of hot end temperatures (T _Hi ), and a plurality of cold junction temperatures (T ) when a thermoelectric chip is mounted in the system. _Ci ). As can be seen from the system diagram of FIG. 1, after the thermocouple temperature sensor 170 measures the temperature of the cold end 121 and the hot end 122 of the thermoelectric chip 120, the temperature data is transmitted to the paperless multi-point recorder 180, and then, The recording unit built in the computer 190 records the temperature data. On the other hand, measuring the voltage and current of the thermoelectric chip is a conventional technique and will not be described herein.

Step 211 uses a calculation unit to substitute voltage (V _i ), current (I _i ), hot end temperature (T _Hi ), and cold junction temperature (T _Ci ) into a first equation V _i =α( T _Hi - T _Ci ) + I _i R , the solution of the cubic equation gives a Becker coefficient (α) and an internal resistance (R). The computing unit is built in the computer 190. The recording unit in the previous step belongs to a part of the computer 190. The computing unit performs the operation of the first equation on the data obtained in step 210 to solve the Becker coefficient (α). And internal resistance (R).

Step 220 inputs a fixed voltage (V) to the thermoelectric chip, and measures a current (I), a hot end temperature (T _H ), a cold end temperature (T _C ), and a thermoelectric chip by a measuring unit. Hot and cold end temperature difference (ΔT). The source of the aforementioned fixed voltage is the power supply 130, and the measuring unit is the thermocouple temperature sensor 170.

Step 221 uses a query unit to query a basic performance graph of the thermoelectric wafer and obtain a uniform cooling capability (Q _C ) of the thermoelectric wafer. The query unit is built in the computer 190. The basic performance curve provided by the original manufacturer of the thermoelectric chip 120 manufacturer is used in the embodiment, and the relevant data of the basic performance graph is filed into the computer 120. Therefore, the query unit can be The cooling capacity (Q _C ) of the thermoelectric wafer 120 is ascertained using the hot and cold end temperature difference (ΔT) measured in step 220.

Step 222 uses the calculation unit to substitute the Schiebeck coefficient (α), the current (I), the cold junction temperature (T _C ), the internal resistance value (R), and the hot and cold end temperature difference (ΔT) into a second equation. , a heat transfer coefficient (K) is obtained.

Step 230 repeats steps 210, 211, 220, 221, and 222 by a verification unit to determine whether the Schiebeck coefficient (α), the internal resistance (R), and the heat transfer coefficient (K) are correct. This step is not necessary, but verifying the correctness of the Sibeck coefficient (α), the internal resistance (R), and the heat transfer coefficient (K) can make the calculation result closer to the real situation.

Step 240 uses a computing unit to substitute the Scheib coefficient (α), the internal resistance (R), and the thermal conductivity (K) into a third-party program. , get a high quality coefficient (Z). The quality factor (Z) is used to judge the merits of the thermoelectric wafer 120. The larger the quality factor (Z), the greater the temperature difference between the cold end 121 and the hot end 122 of the thermoelectric wafer 120, that is, the better the performance.

Step 250 uses a calculation unit to substitute the Sibeck coefficient (α), current (I), cold junction temperature (T _C ), internal resistance (R), heat transfer coefficient (K), and hot and cold end temperature difference (ΔT) into a fourth equation. , to obtain an actual cooling capacity (Q _CR ). The actual refrigeration capacity (Q _CR ) determined in this step 250 is different from the refrigeration capacity (Q _C ) found in step 221; the actual refrigeration capacity (Q _CR ) is the refrigeration capacity of the thermoelectric wafer 120 when it is installed in the system. In other words, the cooling capacity of the thermoelectric wafer 120 when it is dynamic, and the cooling capacity (Q _C ) is the cooling capacity of the thermoelectric wafer when it is tested in the original single wafer.

Step 260 uses the calculation unit to substitute the Schiebeck coefficient (α), the current (I), the hot end temperature (T _H ), the cold junction temperature (T _C ), and the internal resistance value (R) into a fifth equation P = α I ( T _H - T _C ) + I ² R , an input power (P) is obtained.

Step 270 uses the computing unit to substitute the actual cooling capacity (Q _CR ) and the input power (P) into a sixth equation. To obtain a thermoelectric wafer coefficient of performance (COP) in a system. It is worth mentioning that the conventional technique measures the coefficient of performance (COP) of the thermoelectric wafer 120, and the method is complicated and costly because the measurement of the actual refrigeration capacity (Q _CR ) is very difficult; now through this The process steps designed by the embodiment can quickly calculate the coefficient of performance (COP) of the thermoelectric wafer 120. Therefore, the present embodiment can also be applied separately to calculate the actual cooling capacity (Q _CR ) of the thermoelectric wafer 120.

Whether it is experimental or industrial data obtained from experimental measurements, it is usually composed of true value (Ture Value) and error (Error), where the error is unavoidable, and the general academic community can accept an error range of ±10%. The industry also allows an error range of ±30%. The following steps are to verify that the coefficient of performance (COP) calculated in the previous steps is within an acceptable error range.

Step 280: the calculation unit utilizes a seventh equation An experimental error is calculated; the foregoing equation is derived by the applicant through long-term research. Therefore, this step 280 can also be applied separately to calculate the experimental error.

Step 290 is to output the data whose experimental error calculated in step 280 is less than 10%, and draw a map by a drawing unit. The foregoing method of drawing a map is a conventional technique and will not be described herein.

It can be seen from the above embodiments that the method for applying the coefficient of performance of the thermoelectric chip in the computing system of the present disclosure can be applied to the actual cooling capacity (Q _CR ) of the thermoelectric chip and the experimental error, in addition to calculating the coefficient of performance of the thermoelectric chip. The calculation, as a result, fully solves the problem of complicated operation and high cost of the conventional technology.

The present disclosure has been disclosed in the above embodiments, and is not intended to limit the scope of the disclosure, and thus, various modifications and refinements may be made without departing from the spirit and scope of the disclosure. The scope of the disclosure is defined by the scope of the appended claims.

100. . . cooling system

110. . . Box

120. . . Thermoelectric chip

121. . . Cold end

122. . . Hot end

130. . . Power Supplier

140. . . Metal heat conduction block

141. . . Trench

150. . . Flat fin

160. . . Heat sink

170. . . Thermocouple temperature sensor

180. . . Paperless multi-point recorder

190. . . computer

200. . . Method for calculating the coefficient of performance of a thermoelectric chip in a system

210~290. . . step

FIG. 1 is a system diagram of a method for calculating a coefficient of performance of a thermoelectric chip in a computing system according to an embodiment of the present disclosure.

Figure 2 is a partial enlarged view of the method of thermoelectric wafer performance coefficient in the computing system of Figure 1.

3A to 3C are flow charts showing the steps of the method for calculating the coefficient of performance of the thermoelectric chip in the calculation system of Fig. 1.

200. . . Method for calculating the coefficient of performance of a thermoelectric chip in a system

210~290. . . step

Claims (10)

A method for calculating a coefficient of performance of a thermoelectric chip in a system is performed by a computer, comprising: recording, by a recording unit, a plurality of voltages (V _i ), a plurality of currents (I _i ) when a thermoelectric chip is mounted in the system, a plurality of hot end temperatures (T _Hi ) and a plurality of cold end temperatures (T _Ci ); the voltages (V _i ), the currents (I _i ), and the hot end temperatures (T _Hi ) are calculated by a computing unit And the cold junction temperature (T _Ci ) is substituted into a first equation V _i =α( T _Hi - T _Ci )+ I _i R , and the uncoupled cubic equation obtains a Becker coefficient (α) and an internal resistance value (R); a fixed voltage (V) is applied to the thermoelectric chip, and a current (I), a hot end temperature (T _H ), a cold end temperature (T _C ), and a cold heat of the thermoelectric chip are measured by a measuring unit. Temperature difference (ΔT); querying a basic performance curve of the thermoelectric wafer by using a query unit, and obtaining a uniform cooling capacity (Q _C ) of the thermoelectric chip; using the calculation unit to calculate the Schiesbeck coefficient (α), the current (I), the cold end temperature (T _C ), the internal resistance value (R) and the cold and hot end temperature difference (ΔT) are substituted into a second equation Obtaining a heat transfer coefficient (K); using the calculation unit to substitute the Schiesbeck coefficient (α), the internal resistance value (R), and the heat transfer coefficient (K) into a third-party program Obtaining a quality coefficient (Z); using the calculation unit, the Schiesbeck coefficient (α), the current (I), the cold junction temperature (T _C ), the internal resistance value (R), and the heat transfer coefficient (K) And the cold and hot end temperature difference (ΔT) is substituted into a fourth equation Obtaining an actual cooling capacity (Q _CR ); using the calculation unit, the Schiesbeck coefficient (α), the current (I), the hot end temperature (T _H ), the cold end temperature (T _C ), and the The internal resistance value (R) is substituted into a fifth equation P = α I ( T _H - T _C ) + I ² R to obtain an input power (P); and the actual cooling capacity (Q _CR ) is obtained by using the calculation unit And the input power (P) is substituted into a sixth equation To obtain a thermoelectric wafer coefficient of performance (COP) in a system. The method for calculating a coefficient of performance of a thermoelectric chip in a system according to claim 1, further comprising: the calculating unit utilizing a seventh equation Calculate an experimental error. The method for calculating the coefficient of performance of the thermoelectric chip in the system according to claim 2, further comprising: outputting the data with the experimental error less than 10%, and drawing the image by a drawing unit. The method for calculating a coefficient of performance of a thermoelectric chip in a system according to claim 1, further comprising: repeating the first five steps by a verification unit to determine the Scheib coefficient (α), the internal resistance (R), and Whether the heat transfer coefficient (K) is correct or not. A method for calculating the actual cooling capacity of a thermoelectric chip in a system is performed by a computer comprising: a plurality of voltages (V _i ), a plurality of currents (I _i ), and a plurality of numbers when a thermoelectric chip is mounted in the system a hot end temperature (T _Hi ) and a plurality of cold end temperatures (T _Ci ), a Becker coefficient (α) and an internal resistance value (R) are obtained through a calculation unit; and a fixed voltage (V) is input to the thermoelectric chip And measuring a current (I), a hot end temperature (T _H ), a cold end temperature (T _C ), and a cold end temperature difference (ΔT) of the thermoelectric wafer by using a measuring unit; using a query unit Querying a basic performance graph of the thermoelectric wafer, and obtaining a uniform cooling capacity (Q _C ) of the thermoelectric wafer; using the Schiesbeck coefficient (α), the current (I), the cold junction temperature (T _C ), the The internal resistance value (R) and the hot and cold end temperature difference (ΔT) are determined by the calculation unit to obtain a heat transfer coefficient (K); using the Schiesbeck coefficient (α), the internal resistance value (R), and the heat transfer coefficient (K) Calculating a quality coefficient (Z) via the calculation unit; and using the calculation unit to calculate the Schiesbeck coefficient (α), the current (I), and the cold end Temperature (T _C ), the internal resistance (R), the heat transfer coefficient (K), and the hot and cold end temperature difference (ΔT) are substituted into the equation , to obtain an actual cooling capacity (Q _CR ). The method of claim 5, wherein the calculating unit is the voltage (V _i ), the currents (I _i ), and the hot end temperatures (T _Hi ) And the cold junction temperature (T _Ci ) is substituted into the equation V _i =α( T _Hi - T _Ci )+ I _i R , and the Sibeck coefficient (α) and the internal resistance value (R) are obtained after the solution is combined. A method for calculating the actual cooling capacity of a thermoelectric wafer in a system as claimed in claim 5, wherein the calculating unit is the Scheib coefficient (α), the current (I), the cold junction temperature (T _C ), the inner Resistance (R) and the temperature difference between the hot and cold ends (ΔT) are substituted into the equation The heat transfer coefficient (K) is obtained. A method for calculating the actual cooling capacity of a thermoelectric wafer in a system as claimed in claim 5, wherein the calculating unit substitutes the Schiesbeck coefficient (α), the internal resistance value (R), and the heat transfer coefficient (K) into the equation , get the quality factor (Z). A method for calculating an experimental error of a thermoelectric chip performance coefficient in a system by using the actual cooling capacity of the request item 5, which is performed by means of a computer, comprising: utilizing the Becker coefficient (α), the current (I), the hot end Temperature (T _H ), the cold junction temperature (T _C ), and the internal resistance value (R) determine an input power (P) via a calculation unit; and the actual refrigeration capacity (Q _CR ) and the input power (P) substituting the equation via the computing unit Obtaining a coefficient of thermal performance (COP) of a thermoelectric wafer in a system; and using the equation for the calculation unit Calculate an experimental error. The method for calculating the experimental error of the thermoelectric chip performance coefficient in the system by using the actual cooling capacity of the request item 5, as described in claim 9, further comprising: outputting the data with the experimental error less than 10%, and drawing by using a drawing unit Figure.