Thermoelectric power generation device, thermoelectric efficiency test method using thermoelectric power generation device, and thermodynamic second law verification method

Abstract

The invention relates to the field of new energy engineering technology research, in particular to a thermoelectric power generation device, a thermoelectric efficiency testing method using the thermoelectric power generation device and a thermodynamic second law verification method. The invention discloses a thermoelectric power generation device. An outer housing; the heat insulation shell is arranged in the outer shell, a first mounting window is formed in the side face of the heat insulation shell, and a cold liquid space is formed between the heat insulation shell and the outer shell; the thermoelectric power generation sheet is embedded in the first mounting window of the heat insulation shell; the high-temperature heat source comprises a heat conduction container embedded in the inner side of the heat insulation shell, and a hot liquid space is formed in the inner side of the heat conduction container; the heating element clings to the side surface or the bottom surface of the heat-conducting container; the low-temperature heat source comprises a heat dissipation structure arranged in the cold liquid space; the high-temperature side of the thermoelectric power generation sheet clings to the heat conduction container, and the low-temperature side clings to the heat dissipation structure. The liquid medium is used as an intermediate medium for heat conduction, and severe fluctuation of the temperature is avoided.

Description

Technical Field

[0001] The present invention relates to fields such as engineering and technological research and experimental development of new energy engineering technology research and experimental development, and teaching instruments for college physics experiments, and particularly relates to a thermoelectric power generation device, a method for testing the thermoelectric efficiency thereof, and a method for verifying the second law of thermodynamics. Background Art

[0002] The working principle of a thermoelectric power generation device is based on the thermoelectric effect, which converts heat energy into electrical energy output, and it follows the principle of the directionality of heat transfer and spontaneous processes in the second law of thermodynamics. According to the Kelvin statement of the second law of thermodynamics, "it is impossible to manufacture a heat engine that absorbs heat from a single heat source, converts all of it into work, and leaves no other changes." Through the experiment of the thermoelectric power generation device, it can be directly observed that heat is transferred from the high-temperature end to the low-temperature end, and other forms of energy (electrical energy) are converted during this process, thus verifying the universality of the second law of thermodynamics in nature.

[0003] However, in the process of implementing the present invention, the applicant found that existing thermoelectric power generation devices directly transfer heat between the heat source and the thermoelectric power generation chip, which leads to drastic temperature fluctuations and is difficult to accurately control, thus bringing difficulties to the testing of the thermoelectric conversion efficiency. Summary of the Invention

[0004] I. Technical Problems to be Solved

[0005] The present invention is expected to at least partially solve one of the above technical problems.

[0006] II. Technical Solutions

[0007] The first aspect of the present invention provides a thermoelectric power generation device. The thermoelectric power generation device includes: an outer housing; a heat-insulating housing disposed within the outer housing, having a first installation window on its side surface, and forming a cold liquid space between it and the outer housing; a thermoelectric power generation chip embedded in the first installation window of the heat-insulating housing; a high-temperature heat source including: a heat-conducting container fitted inside the heat-insulating housing, whose outer side surface matches the inner side surface of the heat-insulating housing, and forming a hot liquid space inside it; a heating element closely attached to the side surface or bottom surface of the heat-conducting container; a low-temperature heat source including: a heat dissipation structure disposed within the cold liquid space; a liquid cooling circulation system for circulating a liquid medium between the cold liquid space and a cold source; wherein, the high-temperature side of the thermoelectric power generation chip is closely attached to the heat-conducting container, and its low-temperature side is closely attached to the heat dissipation structure; the hot liquid space and the cold liquid space are respectively used to accommodate a high-temperature liquid medium and a low-temperature liquid medium.

[0008] The second aspect of the present invention provides a method for testing the thermoelectric conversion efficiency. The method for testing the thermoelectric conversion efficiency uses the above thermoelectric power generation device and includes:

[0009] Step A: Add a liquid medium to the hot liquid space, cold liquid space, and cold source.

[0010] Step B: Heat the liquid medium in the hot liquid space and start the circulation of the liquid medium between the cold liquid space and the cold source.

[0011] Step C: The main control module records the temperature difference between the liquid media inside the hot liquid space and the cold liquid space; the electrical energy value E output by the electronic load.

[0012] Step D: Calculate the thermoelectric conversion efficiency: where E is the electrical energy generated by the thermoelectric conversion device, Q is the input thermal energy, Q = cmΔT, where c and m are the specific heat capacity and mass of the heat-conducting liquid respectively; ΔT is the temperature change of the liquid medium in the hot liquid space.

[0013] The third aspect of the present invention provides a method for verifying the second law of thermodynamics. This method for verifying the second law of thermodynamics includes:

[0014] Steps A to D in the above thermoelectric conversion efficiency test method;

[0015] Step E: Calculate the Carnot cycle efficiency: where T 热 and T 冷 are the temperatures of the hot liquid and the cold liquid respectively, and the unit of both is Kelvin;

[0016] Step F: Compare the thermoelectric conversion efficiency and the Carnot cycle efficiency.

[0017] III. Beneficial Effects

[0018] From the above technical solutions, the present invention has at least one of the following beneficial effects compared with the prior art:

[0019] (1) In the present invention, a heat-conducting container is used to hold the liquid medium. The heat-conducting container is used as a high-temperature heat source and is closely attached to the high-temperature side of the thermoelectric generation chip; the heat sink is used as a low-temperature heat source and is closely attached to the low-temperature side of the thermoelectric generation chip. The heat sink is immersed in the low-temperature liquid medium, so that the liquid medium is used as an intermediate medium for heat conduction, avoiding violent temperature fluctuations and facilitating the test of the thermoelectric conversion efficiency of the thermoelectric conversion device.

[0020] (2) In the present invention, using two or more thermoelectric generation chips is beneficial to enhancing the intensity of the test signal, thereby ensuring the measurement accuracy. Moreover, multiple thermoelectric generation chips are evenly arranged in the circumferential direction of the heat insulation housing, which is beneficial to the temperature balance of the liquid media inside the hot liquid space S1 and the cold liquid space S2, thus ensuring the accuracy of the test results.

[0021] (3) In the present invention, a semiconductor temperature control chip is also embedded on the second installation window of the heat insulation housing. In the actual device, a purchased semiconductor refrigeration chip 52 is used as the semiconductor temperature control chip. However, this semiconductor refrigeration chip 52 does not simply refrigerate, and it can work in two working states; when the semiconductor temperature control chip is in the first working state, its inner side is the heating surface and the outer side is the refrigeration side; when the semiconductor temperature control chip is in the second working state, its inner side is the refrigeration side and the outer side is the heating surface. The bidirectional control of the semiconductor temperature control chip improves the flexibility in the actual measurement process.

[0022] (4) In the present invention, both the load element and the output detection component are realized by an electronic load. This electronic load is based on 4 MOS transistors and supports multi-tube and multi-core synchronous discharge. This solution has a low design cost, is simple and easy to operate; and at least two channels are designed to ensure the balanced distribution of power, and at the same time, it can be compatible with the accuracy of small currents and dissipate heat in a timely manner for high-power situations; the voltage adopts a four-wire system, which can eliminate the voltage drop of the wire and reduce errors; monitor the temperature of the main board, configure a radiator and a cooling fan to protect the module from overheating and burning out.

[0023] (5) In the present invention, each component is easy to obtain, has a low cost, and strong practicability, and is very suitable for small laboratories and universities to use, and has a high promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the schematic diagram of the principle of the thermoelectric power generation device according to the embodiment of the present invention.

[0025] Figure 2 is the schematic diagram of the connection structure of the thermoelectric power generation device according to the embodiment of the present invention.

[0026] Figure 3 and Figure 4 are respectively Figure 1 the circuit schematic diagram and the water circuit schematic diagram of the thermoelectric power generation device shown.

[0027] Figure 5 and Figure 6 are Figure 1 the frame structure diagram and the frame structure decomposition diagram of the thermoelectric power generation device shown. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] In the present invention, a heat-conducting container is used to hold a liquid medium. The heat-conducting container is used as a high-temperature heat source and is closely attached to the high-temperature side of the thermoelectric power generation chip; the heat sink is used as a low-temperature heat source and is closely attached to the low-temperature side of the thermoelectric power generation chip. The heat sink is immersed in the low-temperature liquid medium, so that the liquid medium is used as an intermediate medium for heat conduction, avoiding violent temperature fluctuations and facilitating the test of the thermoelectric conversion efficiency of the thermoelectric power generation device.

[0029] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0030] Figure 1 This is a schematic diagram of the thermoelectric power generation device according to an embodiment of the present invention. Figure 2 This is a schematic diagram of the connection structure of the thermoelectric power generation device according to an embodiment of the present invention. Figure 3 and Figure 4 respectively are Figure 1 the circuit schematic diagram and the water circuit schematic diagram of the thermoelectric power generation device shown. Figure 5 and Figure 6 are Figure 1 the frame structure diagram and the frame structure decomposition diagram of the thermoelectric power generation device shown. The following will be described in detail the thermoelectric power generation device of this embodiment in conjunction with Figures 1 to 6 to.

[0031] As shown in the figure, the thermoelectric power generation device of this embodiment includes:

[0032] [[ID=2B]]The outer housing 10;

[0033] The heat insulation housing 20, which is arranged inside the outer housing, has a first installation window 21 and a second installation window 22 on its side surface, and forms a cold liquid space S2 between it and the outer housing;

[0034] The high-temperature heat source 30 includes: a heat conduction container 31, which is fitted inside the heat insulation housing, whose outer side surface matches the inner side surface of the heat insulation housing, and forms a hot liquid space S1 inside it; a heating element 32, which is closely attached to the side surface or the bottom surface of the heat conduction container;

[0035] The low-temperature heat source includes: a heat dissipation structure 41, which is arranged in the cold liquid space; a liquid cooling circulation system 42, which is used to circulate the liquid medium between the cold liquid space and the cold source 43;

[0036] The thermoelectric power generation chip 51 is embedded in the first installation window of the heat insulation housing, its high-temperature side is closely attached to the heat conduction container, and its low-temperature side is closely attached to the heat dissipation structure;

[0037] Among them, the hot liquid space S1 and the cold liquid space S2 respectively accommodate a high-temperature liquid medium and a low-temperature liquid medium.

[0038] Those skilled in the art should understand that in this embodiment, the heat conduction container is used to hold the liquid medium, the heat conduction container is used as the high-temperature heat source and is closely attached to the high-temperature side of the thermoelectric power generation chip; the heat sink is used as the low-temperature heat source and is closely attached to the low-temperature side of the thermoelectric power generation chip, and the heat sink is immersed in the low-temperature liquid medium, so as to use the liquid medium as an intermediate medium for heat conduction, avoiding violent temperature fluctuations and facilitating the testing of the thermoelectric conversion efficiency of the thermoelectric power generation device.

[0039] The following will separately elaborate on each part of the thermoelectric power generation device of this embodiment in detail.

[0040] Please refer to Figure 5 and Figure 6 In this embodiment, the thermoelectric power generation device is built with corrugated plastic board as the main body, and then bonded with 704 silicone rubber and PVC special glue. The thermoelectric power generation device as a whole has a double-layer structure. The outer shell, heat insulation shell, heating element, etc. are arranged in the upper structure A, and the water pump and corresponding pipelines of the liquid cooling circulation system are arranged in the lower structure B. The upper structure is provided with a hot liquid space cover A1 and a cold liquid space cover A2. Among them, a third installation window B1 is provided on the side of the lower structure. The third installation window B1 will install a cooling fan to dissipate heat from the water pump.

[0041] In this embodiment, the outer shell 10 and the heat insulation shell 20 are both made of corrugated plastic board. The corrugated plastic board has good heat insulation performance and appropriate strength, good workability, can be bonded with PVC glue, and can be waterproof sealed with 704 silicone rubber.

[0042] Those skilled in the art should understand that in addition to corrugated plastic board, other materials with good heat insulation and waterproof properties can also be used to make the outer shell, etc., and the present invention can also be realized, and it is also within the protection scope of the present invention.

[0043] Please refer to the attached drawings. The outer shell 10 and the heat insulation shell 20 are both in the shape of a cuboid, and their depths are the same. A cold liquid space S2 is formed between the outer shell 10 and the inner shell 20. The front side of the heat insulation shell 20 is fixed on the outer shell 10, and a first installation window 21 is opened on each of its left and right side surfaces, and a second installation window 22 is opened on its rear side surface.

[0044] Those skilled in the art should understand that it is necessary to increase the contact area between the thermoelectric power generation chip and the heat conduction container and the heat dissipation structure as much as possible, so that as much heat as possible can be converted through the thermoelectric power generation chip. Therefore, on the one hand, the surface shape of the thermoelectric power generation chip 51 should match the surface shapes of the heat conduction container 31 and the heat dissipation structure 41, and on the other hand, the area of the thermoelectric power generation chip 51 should be as large as possible.

[0045] In this embodiment, the specifications of the thermoelectric power generation chips 51 are all 40×40×3.7 mm 3 , and this size is adapted to the sizes of the device frame, heat conduction container, etc. in this embodiment. Those skilled in the art should understand that the above sizes are only examples, and the size of the thermoelectric power generation chip can be adjusted according to needs in actual scenarios.

[0046] Previous experiments found that the conversion efficiency of a single power generation chip is low, especially the voltage and current values are particularly small and not easily monitored by the output detection device. Therefore, in this embodiment, multiple power generation chips are used to increase the conversion efficiency, and the voltage is increased in series or the current is increased in parallel.

[0047] Specifically, in this embodiment, two thermoelectric power generation chips 51 are respectively embedded in the corresponding first installation windows, and the semiconductor temperature control chip 52 is embedded in the second installation window 22. Moreover, the joints between the thermoelectric power generation chips and the semiconductor temperature control chips and the heat insulation housing are waterproof sealed with 704 silicone rubber.

[0048] Those skilled in the art should understand that using two or more thermoelectric power generation chips is beneficial to improving the intensity of the test signal, thereby ensuring the measurement accuracy. Moreover, the multiple thermoelectric power generation chips are evenly arranged in the circumferential direction of the heat insulation housing, which is beneficial to the temperature balance of the liquid media inside the hot liquid space S1 and the cold liquid space S2, thus ensuring the accuracy of the test results.

[0049] In this embodiment, a semiconductor temperature control chip is also embedded in the second installation window on the heat insulation housing. In the actual device, the purchased semiconductor refrigeration chip 52 is used as the semiconductor temperature control chip. However, this semiconductor refrigeration chip 52 does not simply refrigerate, and it can work in two working states; when the semiconductor temperature control chip is in the first working state, its inner side is the heating surface and the outer side is the refrigeration side; when the semiconductor temperature control chip is in the second working state, its inner side is the refrigeration side and the outer side is the heating surface. The two-way control of the semiconductor temperature control chip improves the flexibility in the actual measurement process. [[ID=ll]]

[0050] Specifically, there are the following three ways to use the semiconductor refrigeration chip in this embodiment:

[0051] (1) Under normal circumstances, the semiconductor refrigeration chip 52 is not started;

[0052] (2) The semiconductor refrigeration chip is used as a thermoelectric power generation chip to measure the energy conversion of a single thermoelectric power generation chip;

[0053] (3) In special cases, when it is powered separately, one side will refrigerate and the other side will heat. The heating surface faces the high-temperature heat source, and the refrigeration chip faces the low-temperature heat source to appropriately adjust the temperature. Of course, the refrigeration surface and the heating surface can also be interchanged by changing the circuit connection.

[0054] In this embodiment, the high-temperature side of the thermoelectric power generation chip 51 is heated, and the low-temperature side is continuously maintained at a lower temperature, so as to form a temperature difference on both sides of the thermoelectric power generation chip and generate electricity. Since only the temperature of the high-temperature side changes, therefore, during the period when a certain temperature difference is reached, the output can be calculated by using Q = cmΔT. It can be seen that this embodiment conforms to the principle of single variable, that is, the relationship between input and output under different temperature difference conditions can be explored.

[0055] The following introduces the design of the high-temperature side of the thermoelectric generator in this embodiment. Referring to the accompanying drawings, in the space formed inside the heat-insulating housing, there is an upper heat-conducting container 31 and a lower heating element 32. The heat-conducting container 31 is fitted inside the heat-insulating housing, and its outer side surface matches the inner side surface of the heat-insulating housing and is closely attached to the high-temperature side of the thermoelectric generator; a hot liquid space S1 is formed inside it. A relatively high-temperature liquid medium is placed inside the hot liquid space S1. Below the heat-conducting container 31, a heating element 32 is provided. Due to the space occupied by the heating element 32, the depth of the hot liquid space S1 is less than the depth of the cold liquid space S2.

[0056] In this embodiment, a metal square condiment cup is selected as the heat-conducting container, and the thermoelectric generator 51 is closely attached to the outer wall of the square condiment cup to absorb heat; a PTC heating plate is placed at the bottom of the square condiment cup as the heating element 32, and then the temperature of the water is regulated through the heat conduction of the square condiment cup. In addition, a semiconductor temperature control chip 52 is attached to the rear side surface of the square condiment cup. And, in order to improve the heat conduction efficiency, thermal conductive silicone grease is applied between the thermoelectric generator 51, the semiconductor temperature control chip 52 and the square condiment cup.

[0057] Those skilled in the art should understand that using a metal square condiment cup as the heat-conducting container is only an example of the present invention, and the present invention is not limited to this example. In other embodiments of the present invention, other materials with good heat conductivity can also be used to make the heat-conducting container, as long as it is closely attached to the thermoelectric generator at the corresponding position and can smoothly conduct heat from the high-temperature medium to the high-temperature side of the thermoelectric generator. Preferably, the heat-conducting container is made of a metal material, and its shape is one of the following: a rectangular parallelepiped tube shape, a cube tube shape, an inverted frustum shape.

[0058] Those skilled in the art should understand that the PTC heating plate is only one implementation manner of the heating element. In other embodiments of the present invention, other heating elements can also be used. For example, a resistance wire can be used to heat the liquid medium. And, the heating element can also be arranged on the side surface of the heat-conducting container. These deformation methods can also achieve the present invention and are also within the protection scope of the present invention.

[0059] The following introduces the design of the low-temperature side of the thermoelectric generator in this embodiment. The low-temperature heat source is to ensure that the temperature is lower than the hot end. Therefore, the cold end must be maintained at a lower temperature and the temperature of the cold end remains unchanged.

[0060] Please refer to the attached drawings. A cold liquid space S2 is formed between the outer housing 10 and the heat-insulating housing 20. A relatively low-temperature liquid medium is placed in the cold liquid space S2. Inside the cold liquid space, three heat dissipation structures 41 are provided, corresponding to 2 thermoelectric generators and 1 semiconductor temperature control chip respectively. The three heat dissipation structures 41 are respectively fixed on their own heat dissipation structure brackets, and their heat sinks are closely attached to the low-temperature sides of the thermoelectric generators. In order to ensure the heat conduction efficiency between the heat dissipation structure and the temperature difference heat sink, thermal grease is applied between the thermoelectric generator and the heat dissipation structure.

[0061] In this embodiment, the three heat dissipation structures 41 are heat sinks made of metal material, all immersed in the liquid medium of the cold liquid space S2. The water of the low-temperature heat source is continuously updated by water cooling circulation, and the temperature can be kept constant in this way. In order to ensure uniform heat dissipation, a water pump is used to pump the cold water in another cold liquid container into the cold liquid space S2, and a water outlet is arranged opposite to the heat dissipation structure to take away heat; then the same number of water pumps are used to pump the water in the device into the cold liquid container, and the water is circulated and updated in this way to ensure that the temperature at the cold end remains at an initial water temperature value.

[0062] Figure 4 In the figure, the red represents the water to be cooled, and the green line represents the cooling water. The thermoelectric power generation device includes: 2 sets of liquid cooling circulation systems, and each set of liquid cooling circulation system corresponds to a heat dissipation structure. Among them, each set of liquid cooling circulation system includes: a cooling pipeline and a liquid return pipeline, and one water pump is arranged for each of them. Among them, the liquid inlet of the cooling pipeline is connected to the cold liquid container, and the liquid outlet faces the heat sink; the liquid inlet of the liquid return pipeline is far from the heat sink, and the liquid return port is connected to the cold liquid container.

[0063] It should be noted that in this embodiment, both the high-temperature liquid medium and the low-temperature liquid medium are pure water. In other embodiments of the present invention, the high-temperature liquid medium and the low-temperature liquid medium can also be oil or other liquid media, and moreover, the high-temperature liquid medium and the low-temperature liquid medium can also adopt different liquid media.

[0064] Among them, the high-temperature medium is preferably oil or water. The reason is that the temperature of oil will rise quickly and the upper limit value of the temperature is higher. Although the cost of using water is low, the water will boil at 100°C and cannot continue to heat up, so a larger temperature difference cannot be obtained. The low-temperature medium is water, which has a large specific heat capacity and the temperature change is not obvious.

[0065] In addition, two digital thermometers are equipped to monitor the temperature at the cold end, so as to observe in real time whether the water temperature at the cold end is constant. If there is a situation of temperature rise, the semiconductor temperature control chip is powered on to cool towards the low-temperature heat source end to control the temperature.

[0066] In order to detect the electrical performance of the thermoelectric power generation device, in this embodiment, the thermoelectric power generation device further includes: a sensing system, including: a hot-end sensor, whose sensing end is pressed against the outer side of the heat-conducting container or immersed in the high-temperature liquid medium inside the heat-conducting container; a cold-end sensor, whose sensing end is pressed against the outer side of the heat dissipation structure or immersed in the low-temperature liquid medium inside the housing; a load element, connected to the output end of the thermoelectric power generation chip; an output detection component, used to measure the electrical parameters of the circuit composed of the thermoelectric power generation chip and the load element; a main control module, connected to the hot-end sensor, the cold-end sensor, and the output detection component, used to record the temperature difference between the high-temperature liquid medium and the low-temperature liquid medium, and the electrical parameters of the circuit composed of the thermoelectric power generation chip and the load element.

[0067] In this embodiment, both the load element and the output detection component are implemented by an electronic load 61. This electronic load is based on 4 MOS transistors and supports multi-transistor and multi-core synchronous discharging. Moreover, the resistance value of this electronic load is adjustable, and it has the functions of measuring the circuit voltage and open-circuit current; it is signal-connected to the main control module wirelessly; and, the electronic load is powered by an independent power supply independent of the thermoelectric power generation chip and supports the constant resistance mode and the internal resistance measurement function.

[0068] In addition, the main MCU of this electronic load 61 can be designed with STM32, the analog quantity acquisition can use the built-in ADC, and the reference quantity setting adopts PWM filtering processing. This scheme has a low design cost and is simple and easy to operate; and at least two channels are designed to ensure uniform power distribution, and at the same time, it can be compatible with the accuracy of small currents and dissipate heat in a timely manner for high-power situations; the voltage adopts a four-wire system, which can eliminate the voltage drop of the wire and reduce errors; monitor the temperature of the main board and configure a radiator and a cooling fan to protect the module from overheating and burning out.

[0069] In this embodiment, the electronic load is based on 4 MOS transistors, with multi-transistor and multi-core synchronous discharging, and supports seven modes including constant voltage load, constant current load, constant power load, constant resistance load, BRT intelligent one-key internal resistance measurement, PT intelligent one-key power supply measurement, and CT intelligent one-key line resistance measurement. And there are constant current load modes of 10 mA and 1 mA, which can detect more accurately. The test voltage is 0 - 200 V, the working current is 0.2 - 25 A, and the discharge power is not higher than 150 W.

[0070] Those skilled in the art should understand that since the thermoelectric power generation chip is equivalent to a power supply during operation and has an internal resistance, it is analyzed as a pure resistance closed circuit. Let the power supply voltage be E, the internal resistance be r, the load be R, the voltage of the load be U, and the current of the circuit be I. According to the following relevant formulas:

[0071]

[0072] It can be observed that when R = r, the output power P 出 has a maximum value Therefore, when the internal resistance is the same as the load resistance, the output power will be the maximum. For the quantitative calculation of the output end, in this embodiment, the electronic load is a device that consumes electrical energy by controlling the conduction amount of the internal power (MOSFET) and relying on the power dissipation of the power transistor. It can accurately detect the load voltage and current, and simulate various scenarios such as constant current, constant voltage, and constant resistance to measure the power supply, so as to obtain the electrical energy value generated by the thermoelectric generator and calculate the efficiency with the input value.

[0073] Based on this, when using the electronic load in this embodiment:

[0074] I. Measure the internal resistance of the circuit

[0075] Use the electronic load to test the internal resistance of the closed-loop circuit composed of the thermoelectric generator, electronic load, etc.

[0076] II. Maintain the constant internal resistance mode

[0077] Adjust the electronic load to the constant resistance load mode, keep the resistance unchanged, and conduct electrical performance tests.

[0078] In this embodiment, the main control module is a computer, which is connected to the electronic load wirelessly through Bluetooth or other means.

[0079] Based on the above introduction of the structure of the thermoelectric power generation device, the preparation process of the thermoelectric power generation device is introduced below. The preparation process includes:

[0080] Step A, high-temperature heat source design

[0081] Sub-step A1, since the specifications of both the thermoelectric generator 51 and the semiconductor temperature control sheet 52 are 40×40×3.7 mm 3 , the specification of the square flavor cup is 120×120×100 mm 3 , select two sides as the heat conduction surfaces of the thermoelectric generator, then select one side to "embed" the semiconductor temperature control sheet 52, and make heat insulation treatment on the remaining side. Additionally, select a foam board to embed and fix the thermoelectric generator and the semiconductor temperature control sheet, use 704 silicone rubber for waterproof treatment, and apply thermal conductive silicone grease on both sides. Then, stick one side tightly to the square flavor cup and the other side tightly to the metal heat sink to form the heat insulation housing 20.

[0082] Sub-step A2: The square flavor pot is designed to be detachable, that is, it is not completely bonded to the thermoelectric generator. Since the square flavor pot is larger at the top and smaller at the bottom, it can just fit into the designed groove and contact the thermoelectric generator coated with thermal grease. The rest is insulated with styrofoam board. The thermal conductivity coefficient of the styrofoam board is not higher than 0.176 W / (m·K), which has a good heat insulation effect and can minimize the heat exchange between the high-temperature heat source and the low-temperature heat source to the greatest extent. Then, a high-temperature resistant fiberglass aluminum foil tape is pasted on the surface of the styrofoam board for temperature resistance treatment to prevent the device from being damaged due to excessive temperature.

[0083] Sub-step A3: The wiring of the thermoelectric generator is connected in series, and the wire heads are left as output ports. A digital display voltmeter is connected to the output ports to roughly observe the generated voltage. The "embedded" semiconductor temperature control chip can change the wiring method to make the side facing the hot end generate heat and the side facing the cold end refrigerate. It can not only use the heating surface to change the temperature of the heat source, but also use the refrigerating surface to assist in controlling the temperature of the cold end to keep the cold end at the initial temperature. After all the heat sinks are tightly attached to the generator or the refrigerating chip, they are fixed.

[0084] Step B: Design of the low-temperature heat source

[0085] Sub-step B1: Take a white styrofoam board to make a box with dimensions of 300×200×150 mm 3 as the outer shell 10 of the upper structure A. The heat transfer medium is water. Water has a large specific heat capacity and slow temperature rise. According to the size design, it can well maintain the temperature consistent with the room temperature, which is convenient and fast. Then make a box with dimensions of 300×200×60 mm 3 as the lower structure B, which is used to place the water pump and the circuit. Waterproof treatment is carried out on the power part of the liquid cooling circulation system, and then it is stacked below the upper structure A and bonded with special PVC glue. Finally, a PP board is fixed at the bottom of the whole with screws to be used as the base of the whole device to bear the pressure of the whole device when fully loaded with cold water.

[0086] Sub-step B2: Make a hole on the front of the outer shell 10 near the metal heat sink and insert a transparent plastic water pipe and connect a water pump. Since this embodiment mainly experiments on two thermoelectric generators, water flow impact heat dissipation is carried out on each metal heat sink. The water pump extracts the externally placed cold water and flushes it against the heat sink, which can quickly take away the heat and control the cold end temperature to remain at the initial temperature. And a digital display thermometer is placed for each metal heat sink to observe the change of the cold end water temperature in real time and timely control the temperature of the low-temperature heat source.

[0087] Sub-step B3: To control the water volume balance of the cycle, four identical motors are connected in parallel. Two of the motors are used to pump cold water to counteract the heat sink, and the other two motors are used to timely pump the water in the low-temperature heat source to a separate water tank. Continuously circulate the cold water in the two places. If it is found that the temperature at the cold end rises significantly, ice water can be selected for cooling and circulation to keep the water in the low-temperature heat source at the initial value.

[0088] Sub-step B4: For the power part of the water-cooled cycle, a 12V DC water pump is selected. A switch is used to control the overall circuit, and another switch is used to control two of the water pumps. Two cooling fans are installed on the third installation window B1 reserved on the lower layer structure. When the water pump is working, heat dissipation is carried out in a timely manner, and a temperature control module is equipped for the fans. When the temperature reaches the set value, the fans start to dissipate heat.

[0089] Step C: Selection of electronic load

[0090] The electronic load selected in this experiment is based on 4 MOS transistors, with multi-tube and multi-core synchronous discharge, and supports seven modes including constant voltage load, constant current load, constant power load, constant resistance load, BRT intelligent one-key internal resistance measurement, PT intelligent one-key power supply measurement, and CT intelligent one-key line resistance measurement. And there are constant current load modes of 10mA and 1mA, which can detect more accurately. The test voltage is 0 - 200V, the working current is 0.2 - 25A, and the discharge power is not higher than 150W.

[0091] Step D: Device assembly

[0092] In this step, the water pump is integrated into the bottom of the device, all are connected in parallel and then wire heads are left for connecting the power supply; a digital display voltmeter is connected to the output end as a reference, all the plastic hoses are arranged on the back side of the device, the device is sealed with a plexiglass board on the top, and the digital display thermometer is embedded in the front of the device; for the heating part, high-temperature resistant fiberglass aluminum foil tape needs to be pasted for protection, and 704 silicone rubber is used for bonding and waterproofing at the places that need to be waterproof. Finally, a layer of transparent waterproof glue used for decoration is brushed inside the device to reinforce the waterproof performance. A box is designed for the electronic load and then placed beside the device. When in use, the output end wire head is connected with alligator clips, and the temperature probe of the electronic load is placed in the high-temperature heat source to complete the matching.

[0093] So far, the introduction of the thermoelectric power generation device in the embodiment of the present invention is completed.

[0094] Based on the above thermoelectric power generation device, the second aspect of the present invention provides a method for testing the thermoelectric conversion efficiency of a thermoelectric power generation chip. In an exemplary embodiment of the present invention, the method for testing the thermoelectric conversion efficiency includes:

[0095] Step A: Add liquid media to the hot liquid space, cold liquid space, and cold source;

[0096] Step B: Heat the liquid medium in the hot liquid space and start the circulation of the liquid medium between the cold liquid space and the cold source.

[0097] Step C: The main control module records the temperature difference between the liquid media inside the hot liquid space and the cold liquid space; the electrical energy value E output by the electronic load.

[0098] Step D: Calculate the thermoelectric conversion efficiency: where E is the electrical energy generated by the thermoelectric power generation device, Q is the input heat energy, Q = cmΔT, where c and m are the specific heat capacity and mass of the heat-conducting liquid respectively; ΔT is the temperature difference between the hot liquid and the cold liquid.

[0099] Based on the above thermoelectric power generation device, the second aspect of the present invention provides a method for verifying the second law of thermodynamics. In an exemplary embodiment of the present invention, the method for verifying the second law of thermodynamics includes:

[0100] Step A: Add liquid media to the hot liquid space, the cold liquid space, and the cold source.

[0101] Step B: Heat the liquid medium in the hot liquid space and start the circulation of the liquid medium between the cold liquid space and the cold source.

[0102] Step C: The main control module records the temperature difference between the liquid media inside the hot liquid space and the cold liquid space; the electrical energy value E output by the electronic load.

[0103] Step D: Calculate the thermoelectric conversion efficiency: where E is the electrical energy generated by the thermoelectric power generation device, Q is the input heat energy, Q = cmΔT, where c and m are the specific heat capacity and mass of the heat-conducting liquid respectively; ΔT is the temperature change of the liquid medium in the hot liquid space.

[0104] Step E: Calculate the Carnot cycle efficiency: where T 热 and T 冷 are the temperatures of the hot liquid and the cold liquid respectively, and the unit of both is Kelvin.

[0105] Step F: Compare the thermoelectric conversion efficiency and the Carnot cycle efficiency.

[0106] So far, the various embodiments of the present invention have been introduced. Based on the above description, those skilled in the art should have a clear understanding of the present invention.

[0107] It should be noted that, unless explicitly stated to the contrary, the numerical parameters in the description and claims of the present invention may be approximate values and can be changed according to the content of the present invention. Specifically, all the numbers indicating the contents of components, reaction conditions, etc. recorded in the description and claims should be understood to be modified by the term "about" in all cases, and the meaning expressed is that it includes a change of ±10% of a specific quantity in some embodiments.

[0108] The ordinal numbers used in the description and claims, such as "first", "second", "third", "main", "sub", as well as Arabic numerals, letters, etc., are used to modify the corresponding elements (or steps). Their original intention is only to clearly distinguish one element (or step) with a certain name from another element (or step) with the same name, and does not mean that the element (or step) has any ordinal number, nor does it represent the order of one element (or step) and another element (or step). At the same time, unless specifically described or steps that must occur in sequence, the order of the above steps is not limited to those listed above and can be changed or rearranged according to the required design.

[0109] It should also be noted that the directional terms mentioned in the embodiments, such as "center", "lateral", "longitudinal", "top", "bottom", "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship only based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present invention. And throughout the drawings, the same elements are represented by the same or similar reference numerals. And the shapes and sizes of the components in the drawings do not reflect the actual size and proportion, but only illustrate the content of the embodiments of the present invention.

[0110] Those skilled in the art should understand that in the claims and description of the present invention, the word "comprising" does not exclude the existence of elements (or steps) not listed in the claims. The word "a" or "an" before an element (or step) does not exclude the existence of multiple such elements (or steps).

[0111] For some implementations, if they are not the key content of the present invention and are well-known to those of ordinary skill in the art, then due to space limitations, they are not described in detail in the drawings of the description or the text. In this case, reference can be made to the relevant prior art for understanding.

[0112] Moreover, the purpose of providing the above embodiments is only to make the present invention meet the legal requirements, and the present invention can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein.

[0113] Similarly, it should be understood that, for the sake of streamlining the present invention, in the above description of the exemplary embodiments of the present invention, various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present invention should not be construed as reflecting an intention that the claimed invention requires more features than those expressly recited in each claim. Rather, as reflected by the claims, each inventive aspect lies in less than all the features of the preceding single embodiment. Also, the embodiments may be used in combination with each other or with other embodiments based on considerations of design and reliability, that is, the technical features in different embodiments can be freely combined to form more embodiments. Therefore, the claims following the specific embodiments are hereby expressly incorporated into the specific embodiments, where each claim itself serves as a separate embodiment of the present invention.

[0114] In the above specific embodiments, the object, technical means, and beneficial effects of the present invention have been described in detail. It should be understood that the purpose of the detailed description is for those skilled in the art to understand the present invention more clearly, and it is not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A thermoelectric power generation device, characterized in that, Comprising; Outer housing; Heat-insulating housing, disposed within the outer housing, having a first installation window on its side, and forming a cold liquid space between it and the outer housing; Thermoelectric generator, embedded within the first installation window of the heat-insulating housing; High-temperature heat source, comprising: Thermal conduction container, fitted inside the heat-insulating housing, with its outer side surface matching the inner side surface of the heat-insulating housing, and forming a hot liquid space inside it; Heating element, closely attached to the side or bottom surface of the thermal conduction container; Low-temperature heat source, comprising: Heat dissipation structure, disposed within the cold liquid space; Liquid cooling circulation system, used for circulating a liquid medium between the cold liquid space and a cold source; Wherein, the high-temperature side of the thermoelectric generator is closely attached to the thermal conduction container, and its low-temperature side is closely attached to the heat dissipation structure; the hot liquid space and the cold liquid space are respectively used for accommodating a high-temperature liquid medium and a low-temperature liquid medium.

2. The thermoelectric power generation device according to claim 1, characterized in that, Comprising: The side surface of the heat-insulating housing is provided with N first installation windows, N≥2; The thermoelectric power generation device comprises: N thermoelectric generators, respectively embedded in the corresponding first installation windows; the high-temperature side of each thermoelectric generator is closely attached to the thermal conduction container; The thermoelectric power generation device comprises: N heat dissipation structures, wherein the low-temperature side of each thermoelectric generator is closely attached to the corresponding heat dissipation structure; N sets of the above liquid cooling circulation systems, and each set of liquid cooling circulation system corresponds to a heat dissipation structure.

3. The thermoelectric power generation device according to claim 2, wherein The heating element is closely attached to the bottom surface of the thermal conduction container; And / or, the liquid cooling circulation system comprises: a cooling pipeline and a liquid return pipeline, each provided with a water pump, wherein the liquid inlet of the cooling pipeline is connected to a cold liquid container, and the liquid outlet faces the heat dissipation structure; the liquid inlet of the liquid return pipeline is away from the heat dissipation structure, and the liquid return port is connected to the cold liquid container; And / or, further comprising: a heat dissipation structure fixing frame, fixed within the outer housing, and the heat dissipation structure is fixed on the heat dissipation structure fixing frame.

4. The thermoelectric power generation device according to claim 3, wherein The heating element is: a PTC heating plate or a semiconductor heating plate; And / or, the thermal conduction container is made of a metal material, and its shape is one of the following: rectangular cylinder shape, cube cylinder shape, inverted frustum shape; And / or, the thermal conduction container is a square flavor cup made of stainless steel; And / or, the heat dissipation structure is a heat sink made of a metal material; And / or, the outer housing and / or the heat-insulating housing is bonded by a corrugated board; And / or, a heat-conducting silicone grease is applied between the thermal conduction container and the thermoelectric generator; And / or, a heat-conducting silicone grease is applied between the heat dissipation structure and the thermoelectric generator; And / or, the cold source is an external cold liquid container, and its interior contains a low-temperature liquid medium; And / or, the N thermoelectric generators are evenly arranged in the circumferential direction of the side wall of the heat-insulating housing; And / or, the N thermoelectric generators are connected in series or in parallel; And / or, the high-temperature liquid medium and the low-temperature liquid medium are the same medium or different media; And / or, the high-temperature liquid medium is water or oil; And / or, the low-temperature liquid medium is water; And / or, the semiconductor temperature control chip is a semiconductor temperature control chip.

5. The thermoelectric power generation device according to claim 3, characterized in that a second installation window is provided on the side surface of the heat insulation housing; further comprising: a semiconductor temperature control chip, embedded in the second installation window on the side surface of the heat insulation housing, with its inner side tightly attached to the heat conduction container and its outer side tightly attached to the corresponding heat dissipation structure; wherein, when the semiconductor temperature control chip is in the first working state, its inner side is the heating surface and its outer side is the refrigerating side; when the semiconductor temperature control chip is in the second working state, its inner side is the refrigerating side and its outer side is the heating surface.

6. The thermoelectric power generation device according to claim 4, wherein It has a double-layer structure, wherein: the outer housing, the heat insulation housing, and the heating element are arranged in the upper layer structure; the water pump and the corresponding pipelines of the liquid cooling circulation system are arranged in the lower layer structure; wherein, a heat dissipation fan is arranged on the side surface of the lower layer structure.

7. The thermoelectric power generation device according to claim 2, characterized in that, Comprising: a sensing system, including: a hot end sensor, whose sensing end presses against the outer side of the heat conduction container or is immersed in the high-temperature liquid medium in the heat conduction container; a cold end sensor, whose sensing end presses against the outer side of the heat dissipation structure or is immersed in the low-temperature liquid medium in the outer housing; a load element, connected to the output end of the thermoelectric power generation chip; an output detection component, used to measure the electrical parameters of the circuit composed of the thermoelectric power generation chip and the load element; a main control module, connected to the hot end sensor, the cold end sensor, and the output detection component, and used to record the temperature difference between the high-temperature liquid medium and the low-temperature liquid medium, and the electrical parameters of the circuit composed of the thermoelectric power generation chip and the load element.

8. The thermoelectric power generation device according to claim 7, characterized in that both the load element and the output detection component are implemented by an electronic load; the resistance value of the electronic load is adjustable, and it supports the constant resistance mode and the internal resistance measurement function; the electronic load is signal-connected to the main control module in a wireless manner; wherein, the electronic load is based on 4 MOS transistors, supports multi-tube and multi-core synchronous discharge; the electronic load is powered by an independent power supply independent of the thermoelectric power generation chip.

9. A method for testing the thermoelectric conversion efficiency, characterized in that Using the thermoelectric power generation device according to claim 8, including: Step A, adding liquid media to the hot liquid space, the cold liquid space, and the cold source; Step B, heating the liquid medium in the hot liquid space and starting the circulation of the liquid medium between the cold liquid space and the cold source; Step C, the main control module records the temperature difference between the liquid media inside the hot liquid space and the cold liquid space; the electric energy value E output by the electronic load; Step D, calculate the thermoelectric conversion efficiency: Wherein, E is the electric energy generated by the thermoelectric power generation device, Q is the input heat energy, Q = cmΔT, where c and m are the specific heat capacity and mass of the heat-conducting liquid respectively; ΔT is the temperature change of the liquid medium in the hot liquid space.

10. A method for verifying the second law of thermodynamics, characterized in that, Including; Steps A to D in the thermoelectric conversion efficiency test method according to claim 9; Step E, calculate the Carnot cycle efficiency: where, T 热 and T 冷 are the temperatures of the hot fluid and the cold fluid respectively, and the unit of both is Kelvin; Step F, comparing the thermoelectric conversion efficiency and the Carnot cycle efficiency.

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