Thermoelectric generator and diverging fin thickness obtaining method thereof

Abstract

The invention relates to the field of thermoelectricity, in particular to a thermoelectric generator and a diverging fin thickness obtaining method thereof, and the thermoelectric generator comprises a heat exchanger which comprises a heat exchange shell, a hollow cylinder and a plurality of diverging fins arranged between the heat exchange shell and the hollow cylinder, the thicknesses of the diverging fins are continuously increased in the tail gas flowing direction; compared with a traditional fin, the diverging fin has the advantages that the thickness of the diverging fin is not fixed and is gradually increased in the flowing direction of heat flow (tail gas); the structure can effectively counteract adverse effects caused by temperature drop of the fins, so that the surface temperature of the heat exchanger is remarkably increased in the downstream direction of heat flow (tail gas), meanwhile, the temperature uniformity of the surface of the heat exchanger is greatly improved, and high efficiency and stability of the heat exchange process are ensured.

Description

Technical Field

[0001] The invention relates to the field of thermoelectricity, and in particular to a thermoelectric generator and a method for obtaining the thickness of a divergent fin thereof. Background Art

[0002] To address global climate change issues and growing energy demand, the use of waste heat to generate electricity offers a promising solution to use this abundant energy resource to offset part of the electricity demand. Thermoelectric generators are reliable solid-state devices that can generate electricity continuously when a temperature difference is applied across them. They can be used to recover heat from waste heat sources such as exhaust gases from primary heat sources such as automobiles.

[0003] Although thermoelectric generators have made significant progress in recent years, they still face some challenges. The low efficiency and high cost of TEG have hindered its large-scale commercial production. A typical thermoelectric generator consists of a radiator, a heat exchanger and a thermoelectric module. Among them, since the heat exchanger structure has a great influence on the output performance of the thermoelectric generator, there are endless studies on the heat exchanger structure. Inserting fins in the heat exchanger can increase the heat transfer area between it and the heat flow, increase the hot end temperature of the thermoelectric module, and obtain greater output performance. And the fins have the advantages of low cost, simple installation and high efficiency, and are suitable for integration with the heat exchanger.

[0004] However, there are the following problems with fins in practical applications. The fin temperature is highest at the heat flow inlet and gradually decreases along the heat flow direction, which will result in a lower surface temperature of the heat exchanger downstream of the heat flow; this will reduce the output performance of the thermoelectric module located downstream of the heat flow. In addition, since the overall output current is limited to the minimum output current in the thermoelectric module when the thermoelectric modules are connected in series, the overall output voltage will be limited to the minimum output voltage when connected in parallel. Therefore, this phenomenon will cause the overall output power of the thermoelectric generator to be low, resulting in a waste of electrical energy. Summary of the invention

[0005] In response to the problems mentioned in the prior art, the present invention proposes a thermoelectric generator and a method for obtaining the thickness of its diverging fins. By adjusting the thickness of the diverging fins, the heat exchanger can absorb more heat from the exhaust gas and improve the temperature uniformity of the heat exchanger surface, thereby overcoming the problem of limited performance of the thermoelectric module and effectively improving the output performance of the thermoelectric generator.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The present invention provides a thermoelectric generator, comprising: A heat exchanger, comprising a heat exchange shell, a hollow cylinder, and a plurality of diverging fins disposed between the heat exchange shell and the hollow cylinder, wherein the thickness of the diverging fins increases continuously along the flow direction of the exhaust gas; A plurality of thermoelectric modules, each surface of the heat exchanger is provided with a thermoelectric module along the length direction; A heat sink is bonded to the thermoelectric module.

[0007] As a further improvement of the present invention, the heat exchange shell, the hollow cylinder and the diverging fins are of the same length; The outer cross section of the heat exchange shell is a regular hexagon, and the inner cross section is a circle.

[0008] As a further improvement of the present invention, the upper surface of the diverging fin is closely connected to the heat exchange shell, and the lower surface is closely connected to the hollow cylinder.

[0009] As a further improvement of the present invention, the thermoelectric module includes a ceramic plate, a copper electrode, a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor; the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are connected by the copper electrode and are arranged between two ceramic plates.

[0010] As a further improvement of the present invention, the radiator includes a shell and an S-shaped cooling medium channel arranged in the shell, and a channel inlet and a channel outlet are provided on the same side of the shell, wherein the medium inlet of the cooling medium channel is connected to the channel inlet, and the medium outlet of the cooling medium channel is connected to the channel outlet.

[0011] A method for obtaining the thickness of a diverging fin of a thermoelectric generator comprises the following steps: S1: Obtain the parameters of the thermoelectric generator and the divergent fins; S2: The cross section of the divergent fin is a trapezoid, and the divergence angle is the angle formed between the waist of the trapezoid and the height of the trapezoid; S3: Establish a finite element model according to the parameters of the thermoelectric generator and the divergent fin parameters, set boundary conditions for the finite element model, input divergent fins with different divergence angles into the finite element model for simulation, and obtain performance parameters of different thermoelectric generators; S4: Compare the performance parameters of different thermoelectric generators to obtain the optimal thickness of the divergent fins.

[0012] As a further improvement of the present invention, the parameters of the thermoelectric generator in step S1 include the diameter of the cooling medium channel, the length of the heat exchange shell and the hollow cylinder, the inner diameter of the heat exchange shell, the radius of the hollow cylinder, the number of thermoelectric modules, the number of diverging fins, the length, width and height of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor, the height of the copper electrode, and the length, width and height of the ceramic plate.

[0013] As a further improvement of the present invention, the divergent fin parameters in step S1 include the radii of the upper and lower side arcs of the longitudinal section of the divergent fin, the arc angle of the longitudinal section of the divergent fin close to the exhaust gas inlet end, and the length of the divergent fin.

[0014] As a further improvement of the present invention, the boundary conditions in step S2 are the initial ambient temperature, the surface convection heat transfer coefficient of the thermoelectric generator in contact with the air, the external resistance, the cooling medium flow rate, the cooling medium inlet temperature, the cooling medium inlet flow rate, the heat flow inlet surface temperature and the mass flow rate of the heat flow.

[0015] As a further improvement of the present invention, the specific process in step S4 is: comparing the output power and net power of different thermoelectric generators, when the output power and net power are optimal, the divergent fins with the optimal thickness are obtained, and the specific expression is as follows:

[0016] Where: is the net power; is the output power; is the back pressure loss;

[0017] Where: Ui For the i The output voltage of each thermoelectric module; R L For external load;

[0018] Where: V is the volume flow rate of heat flow; is the pressure difference between the heat flow inlet and the heat flow outlet.

[0019] Compared with the prior art, the present invention has achieved the following technical effects: Compared with traditional fins, the improvement of the diverging fins of the present invention is that the thickness of the diverging fins is not fixed, but gradually increases along the direction of the heat flow (exhaust gas) flow; this structure can effectively offset the adverse effects brought about by the drop in fin temperature, and thus significantly enhance the surface temperature of the heat exchanger in the downstream direction of the heat flow (exhaust gas); at the same time, this structure also greatly improves the temperature uniformity of the heat exchanger surface, ensuring the high efficiency and stability of the heat exchange process.

[0020] The present invention uses COMSOL finite element software to conduct an in-depth performance comparison analysis. Through simulation and calculation, the performance differences between thermoelectric generators equipped with traditional fins and divergent fins are compared. The diverging fins of the present invention have shown significant advantages in improving heat exchange efficiency, optimizing temperature distribution and increasing net output power.

[0021] Compared with the existing thermoelectric generators, the present invention achieves a significant improvement in the performance of the thermoelectric generator by installing divergent fins. Benefiting from the improved temperature uniformity, when multiple thermoelectric modules are cascaded, the power loss is effectively reduced; it not only optimizes the thermoelectric conversion process, but also greatly improves the net output power of the thermoelectric generator, making it more efficient in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the thermoelectric generator of the present invention; Figure 2 It is a schematic diagram of the cooling medium channel of the present invention; Figure 3 It is a structural schematic diagram of the thermoelectric module of the present invention; Figure 4 It is a structural schematic diagram of the heat exchanger of the present invention; Figure 5 It is a structural schematic diagram of the divergent fin of the present invention; Figure 6 It is a cross-sectional schematic diagram of the divergent fin of the present invention.

[0023] Figure numerals: 1, radiator; 2, thermoelectric module; 101, channel inlet; 102, channel outlet; 201, ceramic plate; 202, copper electrode; 203, P-type thermoelectric semiconductor; 204, N-type thermoelectric semiconductor; 301, heat exchange shell; 302, divergent fin; 303, hollow cylinder; 401, longitudinal section of the starting end of the divergent fin; 402, cross section of the divergent fin. DETAILED DESCRIPTION

[0024] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0025] The examples of the present application are described in detail below, and the examples of the examples are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The examples described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0026] like Figure 1As shown, a thermoelectric generator of the present invention comprises: a heat exchanger, the heat exchanger comprises a heat exchange shell 301, a hollow cylinder 303, and a plurality of diverging fins 302 arranged between the heat exchange shell 301 and the hollow cylinder 303, wherein the thickness of the diverging fins 302 increases continuously along the flow direction of the exhaust gas; a plurality of thermoelectric modules 2, wherein each surface of the heat exchanger is fitted with a thermoelectric module 2 along the length direction; a radiator 1, wherein the radiator 1 is fitted and connected to the thermoelectric module 2. The heat exchange shell 301, the hollow cylinder 303, and the diverging fins 302 have the same length; wherein the outer cross-section of the heat exchange shell 301 is a regular hexagon, and the inner cross-section is a circle. The upper surface of the diverging fin 302 is fitted and connected to the heat exchange shell 301, and the lower surface is fitted and connected to the hollow cylinder 303.

[0027] like Figure 4 As shown, the heat exchanger in the embodiment is a device that transfers part of the heat of a hot fluid to a cold fluid, wherein the heat exchange shell 301 uses a thin metal plate with a hexagonal corrugated surface as a heat transfer element, and specifically, the outer side of the cross section of the heat exchange shell 301 is designed to be an equilateral hexagon, and the inner side of the cross section is designed to be circular, and the outer side of the cross section is concentric with the inner side of the cross section. like Figure 5 As shown, in the embodiment, the hollow cylinder 303 is arranged in the heat exchange shell 301, and the center of the hollow cylinder 303 coincides with the center of the inner side of the cross section of the heat exchange shell 301. The divergent fins 302 of the present invention are evenly distributed along the circumference of the hollow cylinder 303, and the two ends of the divergent fins 302 are respectively connected to the heat exchange shell 301 and the hollow cylinder 303.

[0028] The inner diameter of the heat exchange shell 301 needs to be obtained in the subsequent method for obtaining the thickness of the divergent fin 302. R 1. Cross-sectional radius of the hollow cylinder 303 R 2. Install n The lengths of the diverging fins 302, the diverging fins 302, the heat exchange shell 301 and the hollow cylinder 303 are L 1. Such as Figure 4 and Figure 5 As shown, in the embodiment, since the heat exchange shell 301 and the hollow cylinder 303 have the same length, the length of the diverging fin 302 is the same as that of the heat exchange shell 301 and the hollow cylinder 303. L 1. The width of the heat exchange shell 301 is also required L 2.

[0029] like Figure 3 As shown, the thermoelectric module 2 includes a ceramic plate 201 , a copper electrode 202 , a P-type thermoelectric semiconductor 203 and an N-type thermoelectric semiconductor 204 ; the P-type thermoelectric semiconductor 203 and the N-type thermoelectric semiconductor 204 are connected via the copper electrode 202 and are disposed between two ceramic plates 201 .

[0030] Figure 3 As shown, in the embodiment, the P-type thermoelectric semiconductor 203 and the N-type thermoelectric semiconductor 204 are connected in series through the copper electrode 202 and sandwiched between the upper and lower ceramic plates 201; each thermoelectric module 2 includes thermoelectric semiconductors in the same rows and columns, and the geometric parameters of the P-type thermoelectric semiconductor 203 and the N-type thermoelectric semiconductor 204 arranged in the same thermoelectric module 2 are the same; in the embodiment, the number of the P-type thermoelectric semiconductor 203 and the N-type thermoelectric semiconductor 204 on each thermoelectric module 2 is the same, which is n, n = 1, 2, 3, ..., and the number of the copper electrodes 202 is 2n, 2n = b 2 -2.

[0031] The subsequent divergent fin 302 thickness acquisition method needs to obtain the number of thermoelectric modules 2 on each surface of the heat exchanger m , the height, length and width of the ceramic plate 201 in the thermoelectric module 2, the thickness of the copper electrode 202, the length, width and height of the P-type thermoelectric semiconductor 203 and the N-type thermoelectric semiconductor 204, the length, width and height of the P-type thermoelectric semiconductor 203 and the N-type thermoelectric semiconductor 204 in the embodiment are the same, and the row spacing of the P-type thermoelectric semiconductor 203 and the N-type thermoelectric semiconductor 204 is also the same.

[0032] like Figure 2 As shown, the radiator 1 includes a shell and an S-shaped cooling medium channel arranged in the shell, and a channel inlet 101 and a channel outlet 102 are provided on the same side of the shell, wherein the medium inlet of the cooling medium channel is connected to the channel inlet 101, and the medium outlet of the cooling medium channel is connected to the channel outlet 102.

[0033] In the embodiment, a plurality of radiators 1 are provided, and the plurality of radiators 1 are evenly distributed along each surface of the hexagonal heat exchange shell 301, wherein a cooling medium channel is provided in the shell, and the cooling medium channel is an S-shaped cylinder arrangement, and the S-shaped channel can extend the passage time of the cooling medium and further improve the cooling effect; in the embodiment, as Figure 1 As shown, a channel inlet 101 and a channel outlet 102 are respectively provided at the left and right ends of the same side of the shell, wherein the channel inlet 101 is connected with the medium inlet of the cooling medium channel, and the channel outlet 102 is connected with the medium outlet of the cooling medium channel, to ensure that the cooling medium can pass smoothly. The cooling medium in this embodiment is preferably cooling water.

[0034] The subsequent method for obtaining the thickness of the divergent fin 302 needs to obtain the diameter of the cooling medium channel. d .

[0035] The present invention provides a method for obtaining the thickness of a diverging fin of a thermoelectric generator, comprising the following steps: S1: Obtain the parameters of the thermoelectric generator and the divergent fins; S2: The cross section of the divergent fin is a trapezoid, and the divergence angle is the angle formed between the waist of the trapezoid and the height of the trapezoid; S3: Establish a finite element model according to the parameters of the thermoelectric generator and the divergent fin parameters, set boundary conditions for the finite element model, input divergent fins with different divergence angles into the finite element model for simulation, and obtain performance parameters of different thermoelectric generators; S4: Compare the performance parameters of different thermoelectric generators to obtain the optimal thickness of the divergent fins.

[0036] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments: First, the thermoelectric generator parameters are obtained, including the cooling medium channel diameter, the length of the heat exchange shell and the hollow cylinder, the inner diameter of the heat exchange shell, the radius of the hollow cylinder, the number of thermoelectric modules, the number of divergent fins, the length, width and height of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor, the height of the copper electrode, and the length, width and height of the ceramic plate. The thermoelectric generator parameters are shown in Table 1 below: Table 1 Geometric parameters of hexagonal thermoelectric generator

[0037] like Figure 6 As shown, the divergent fin parameters of this embodiment include that the upper and lower sides of the longitudinal section of the divergent fin are concentric arcs with the same angle, and the radii of the inner and outer arcs are respectively R 2 and R 1. In the embodiment, the radii of the inner and outer arcs of the divergent fins are respectively R 2 and R 1 is the same as the parameters of the inner diameter R1 of the hexagonal heat exchanger shell and the radius R2 of the hollow cylinder in Table 1 above, and the longitudinal section arc angle θ of the longitudinal section 401 at the beginning of the divergent fin; Figure 6 The cross section 402 of the divergent fin shown in FIG. 4 is an isosceles trapezoid, and the waist of the isosceles trapezoid is perpendicular to the vertical line segment between the two bottoms. H The divergence angle between α , by obtaining the divergence angle α The variation process of the divergent fin thickness is obtained.

[0038] According to the data in Table 1, the simulation model was established using COMSOL finite element software, and boundary conditions were set for different divergence angles. α The divergent fin thermoelectric generator was numerically simulated to obtain the performance parameters of different thermoelectric generators. The performance parameters were compared. When the output power and net power in the performance parameters reached the optimum, it means that the divergence angle α The thickness of the divergent fins varies to the optimum thickness.

[0039] The specific expression is as follows:

[0040] Where: is the net power; is the output power; is the back pressure loss;

[0041] Where: Ui For the i The output voltage of each thermoelectric module; R L For external load;

[0042] Where: V is the volume flow rate of heat flow; is the pressure difference between the heat flow inlet and the heat flow outlet.

[0043] The COMSOL simulation boundary conditions in the embodiment are shown in Table 2, the average temperature of the hot end of each thermoelectric module on the surface of the heat exchanger (arranged in sequence along the direction of heat flow) is shown in Table 3, and other output parameters are shown in Table 4.

[0044] Table 2 Boundary conditions of COMSOL simulation

[0045] Table 3 Average temperature of the hot end of the thermoelectric module

[0046] Table 4 Simulation output parameters

[0047] According to Table 3, compared with the traditional fins ( α =0°), when α =0.15°, the average temperature of the hot end of the fifth thermoelectric module in the downstream direction of the heat flow in the thermoelectric generator increased by 5.73K, and α The larger the value is, the more obvious the temperature gain is. It can be seen that the design of the divergent fins effectively increases the hot end temperature of the thermoelectric module downstream of the heat flow, thereby improving the temperature uniformity of the heat exchanger surface.

[0048] It can be seen from Table 4 that the output power and back pressure loss increase with α increases with the increase of , while the net power increases first and then decreases; when α =0.15°, the output performance of the thermoelectric generator reaches the best, compared with the traditional fins ( α =0°), the output power increased by 7.39% and the net power increased by 4.83%.

[0049] Compared with traditional fins, the improvement of the diverging fins of the present invention is that the thickness of the diverging fins is not fixed, but gradually increases along the direction of the heat flow (exhaust gas) flow; this structure can effectively offset the adverse effects brought about by the drop in fin temperature, and thus significantly enhance the surface temperature of the heat exchanger in the downstream direction of the heat flow (exhaust gas); at the same time, this structure also greatly improves the temperature uniformity of the heat exchanger surface, ensuring the high efficiency and stability of the heat exchange process.

[0050] The present invention uses COMSOL finite element software to conduct an in-depth performance comparison analysis. Through simulation and calculation, the differences in performance between thermoelectric generators equipped with traditional fins and divergent fins are compared. The divergent fins of the present invention show significant advantages in improving heat exchange efficiency, optimizing temperature distribution, and increasing net output power.

[0051] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0052] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0054] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A thermoelectric generator, characterized in that: include: A heat exchanger, comprising a heat exchange shell, a hollow cylinder, and a plurality of diverging fins disposed between the heat exchange shell and the hollow cylinder, wherein the thickness of the diverging fins increases continuously along the flow direction of the exhaust gas; A plurality of thermoelectric modules, each surface of the heat exchanger is provided with a thermoelectric module along the length direction; A heat sink is bonded to the thermoelectric module.

2. A thermoelectric generator according to claim 1, characterized in that: The heat exchange shell, the hollow cylinder and the diverging fins have the same length; The outer cross section of the heat exchange shell is a regular hexagon, and the inner cross section is a circle.

3. A thermoelectric generator according to claim 2, characterized in that: The upper surface of the divergent fin is connected to the heat exchange shell, and the lower surface is connected to the hollow cylinder.

4. A thermoelectric generator according to claim 1, characterized in that: The thermoelectric module comprises a ceramic plate, a copper electrode, a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor; the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are connected via the copper electrode and are arranged between two ceramic plates.

5. A thermoelectric generator according to claim 1, characterized in that: The radiator includes a shell and an S-shaped cooling medium channel arranged in the shell. A channel inlet and a channel outlet are arranged on the same side of the shell, wherein the medium inlet of the cooling medium channel is connected to the channel inlet, and the medium outlet of the cooling medium channel is connected to the channel outlet.

6. A method for obtaining the thickness of a diverging fin of a thermoelectric generator according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Obtain the parameters of the thermoelectric generator and the divergent fins; S2: The cross section of the divergent fin is a trapezoid, and the divergence angle is the angle formed between the waist of the trapezoid and the height of the trapezoid; S3: Establish a finite element model according to the parameters of the thermoelectric generator and the divergent fin parameters, set boundary conditions for the finite element model, input divergent fins with different divergence angles into the finite element model for simulation, and obtain performance parameters of different thermoelectric generators; S4: Compare the performance parameters of different thermoelectric generators to obtain the optimal thickness of the divergent fins.

7. The method for obtaining the thickness of divergent fins of a thermoelectric generator according to claim 6, characterized in that: The parameters of the thermoelectric generator in step S1 include the diameter of the cooling medium channel, the length of the heat exchange shell and the hollow cylinder, the inner diameter of the heat exchange shell, the radius of the hollow cylinder, the number of thermoelectric modules, the number of diverging fins, the length, width and height of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor, the height of the copper electrode, and the length, width and height of the ceramic plate.

8. The method for obtaining the thickness of divergent fins of a thermoelectric generator according to claim 6, characterized in that: The divergent fin parameters in step S1 include the radius of the upper and lower side arcs of the longitudinal section of the divergent fin, the arc angle of the longitudinal section of the divergent fin close to the exhaust gas inlet end, and the length of the divergent fin.

9. The method for obtaining the thickness of divergent fins of a thermoelectric generator according to claim 6, characterized in that: The boundary conditions in step S2 are the initial ambient temperature, the surface convection heat transfer coefficient of the thermoelectric generator in contact with the air, the external resistance, the cooling medium flow rate, the cooling medium inlet temperature, the cooling medium inlet flow rate, the heat flow inlet surface temperature and the mass flow rate of the heat flow.

10. The method for obtaining the thickness of divergent fins of a thermoelectric generator according to claim 6, characterized in that: The specific process in step S4 is: comparing the output power and net power of different thermoelectric generators, when the output power and net power are optimal, the divergent fins with the optimal thickness are obtained, and the specific expression is as follows: Where: is the net power; is the output power; is the back pressure loss; Where: Ui For the i The output voltage of each thermoelectric module; R L For external load; Where: V is the volume flow rate of heat flow; is the pressure difference between the heat flow inlet and the heat flow outlet.

Images