WO2022016499A1

WO2022016499A1 - Series-parallel thermoelectric power generation sheet having high thermoelectric conversion efficiency

Info

Publication number: WO2022016499A1
Application number: PCT/CN2020/104080
Authority: WO
Inventors: 张征; 陈子健; 陈冬波
Original assignee: 华南理工大学
Priority date: 2020-07-24
Filing date: 2020-07-24
Publication date: 2022-01-27

Abstract

A series-parallel thermoelectric power generation sheet having high thermoelectric conversion efficiency, comprising a cold end face, a hot end face and thermocouple combination units located between the cold end face and the hot end face. The cold end face is divided into a cooling area (A) and a non-cooling area (B), wherein the cooling area (A) is in contact with a cold source, and wherein the non-cooling area (B) is not in contact with the cold source; the hot end face makes complete contact with a heat source; and the thermocouple combination units use short thermocouple arm combinations and long thermocouple arm combinations to construct a parallel and series loop of thermocouples, and are equivalent to one or more simple thermocouples connected in parallel. The series-parallel thermoelectric power generation sheet comprises a plurality of thermocouple combination units. Multiple columns of thermocouple combination units are longitudinally arranged on the two sides of the center line of the series-parallel thermoelectric power generation sheet, and different columns of thermocouple combination units are connected in series by means of turning metal flow deflectors to form an integral thermocouple conversion circuit. The thermoelectric power generation sheet has the characteristics of large output current and good external characteristics, and the thermoelectric conversion efficiency is remarkably improved.

Description

A hybrid thermoelectric power generation sheet with high thermoelectric conversion efficiency

technical field

The invention relates to the technical field of thermoelectric power generation, in particular to a hybrid thermoelectric power generation sheet with high thermoelectric conversion efficiency.

Background technique

Thermoelectric sheet is a semiconductor component that can directly convert thermal energy into electrical energy. Its basic theory is the thermoelectric effect. The key technologies include: the research and development and preparation of thermoelectric materials, and the design and manufacture of thermocouple arrays. The existing thermoelectric power generation sheet generally adopts a three-layer structure. The upper and lower layers are the cold end face and the hot end face covered by the insulating sheet. When working, they contact the cold source and the heat source respectively. The middle layer is provided with multiple sets of thermocouples connected in series, which is used for thermoelectric conversion. element. The arms of the thermocouple are made of strip-shaped n-type and p-type semiconductor materials, which are of the same height and are set upright, and play the dual role of a conductive circuit and a heat-conducting heat circuit during operation. The two top ends of the thermocouple arm are alternately connected with metal guide plates to form the cold junction and hot junction of the thermocouple circuit. Therefore, the circuits of the thermoelectric sheets are connected in series, and the thermal circuits are connected in parallel.

Thermoelectric sheets are the core components of thermoelectric conversion devices. Thermoelectric conversion efficiency is one of its most important technical indicators, which is defined as the ratio of the output electrical energy to the heat absorbed by the hot end (the heat absorbed by the hot end includes the heat required for thermoelectric conversion and its own thermal conductivity). At present, the thermoelectric conversion efficiency of thermoelectric power generation sheet is only about 4.5%, which is the biggest obstacle in practical application. In order to solve this problem, the scientific and technological circles have been developing high-performance thermoelectric materials for making thermocouple arms. There is no obvious progress in the research and development results. The reason is that it is extremely difficult to require a thermoelectric material to satisfy the three conditions of high Seebeck coefficient, low electrical resistance and low thermal conductivity at the same time. In addition, in the prior art, the structural defects of the thermoelectric power generation sheet also make it difficult to improve the thermoelectric conversion efficiency. The reasons are: (1) The thermocouples of the thermoelectric power generation sheet are all connected in series. The advantages are that the circuit is relatively simple and the voltage can be superimposed. The disadvantage is that the internal resistance is very large, which leads to the reactive power loss of electricity; (2) the two ends of all the thermocouple arms contact the cold end face and the hot end face respectively, forming a parallel connection of the heat conduction heat circuit. Due to the existence of temperature difference, the thermocouple arms A large amount of thermal conductivity is inevitably generated between the cold end and the hot end, resulting in reactive power loss of heat absorption at the hot end.

SUMMARY OF THE INVENTION

In order to overcome the above shortcomings of the prior art, the present invention provides a hybrid thermoelectric power generation sheet with high thermoelectric conversion efficiency. Starting from the structural design, the thermoelectric power generation sheet of the present invention has the characteristics of large output (operating) current, good external characteristics, and remarkably improved thermoelectric conversion efficiency.

The present invention adopts the following technical solutions to realize:

The hybrid thermoelectric power generation sheet with high thermoelectric conversion efficiency of the present invention (abbreviation: thermoelectric power generation sheet) still maintains the external dimensions, thermoelectric materials and the scale of the thermocouple arm array of the existing thermoelectric power generation sheet. The hot end face (hot face) of the thermoelectric sheet is still in full contact with the heat source to ensure maximum heat extraction from the heat source. The principle of changing the cold end face (cold face) is to allow only part of the surface area to contact the cold source, that is, to reduce the heat transfer by reducing the heat conduction area of the cold face. At the same time, a new type of hybrid thermocouple combination unit with multiple contacts is provided, which solves the problems caused by the circuits in the prior art that are completely connected in series and the thermal circuits are completely connected in parallel, so as to improve the thermoelectric conversion efficiency. Purpose. specifically:

(1) According to the principle of heat transfer, the heat transfer along the solid is proportional to the temperature difference between its two ends, the thermal conductivity, and the heat transfer area, and is inversely proportional to the heat transfer distance. Therefore, the present invention divides the cold end face of the thermoelectric power generation sheet into a cooling area and a non-cooling area. The cooling area needs to be in contact with the cold source, while the non-cooling area does not need to be in contact with the cold source, and the two areas are separated from each other without heat transfer. The smaller the cooling area, the less the total heat absorbed by the hot end face is transferred to the cold end face through the thermocouple arm.

(2) According to the principle of electrical engineering, the resistance of the thermocouple arm is proportional to its resistivity and length, and inversely proportional to its cross-sectional area; the basic principle of the thermocouple loop points out that the parallel use of the hot junctions of multiple thermocouple combination units can improve thermoelectric conversion. current value. Therefore, the present invention designs the thermocouple arms into two sizes: short arm and long arm, their cross-sectional areas are equal but the heights are different, the resistance value of the short arm is smaller than that of the long arm, and the total resistance value of all the thermocouple arms can be reduced . The thermocouple combination unit takes the form of a short arm combination and a long arm combination to construct a thermocouple circuit, wherein each pair of n-type material short arm combination and p-type material short arm combination is connected to form two thermal junctions of the thermocouple combination unit , the hot end of each pair of n-type material long arm combination and p-type material long arm combination is connected to form another hot junction of the thermocouple combination unit. The hot junction is only heated by the heat source without cooling by the cold source, so it has the same temperature , a thermocouple combination unit can have multiple hot junctions and be connected in parallel; and the cold ends of the long arm combination are respectively connected with the cold ends of the special-shaped material long arm combination of the adjacent unit, forming two cold ends of the thermocouple combination unit. Contacts, cold junctions require cooling from the cold source. Under the condition that the scale of the combined array of thermocouple arms remains unchanged, the invention increases the number of hot junctions and reduces the number of cold junctions.

(3) The present invention proposes the principle of co-design of the circuit and the thermal circuit, and sets the thermocouple arm combinations in the cooling area and the non-cooling area respectively according to their functions. The combination of thermocouple arms set in the non-cooling area is all the combination of short arms; in the cooling area, the combination of thermocouple arms set is the combination of long arm and short arm, wherein the height of the long arm is unchanged, its resistance value and thermal conductivity The function is also unchanged, and it is still connected in parallel as a hot circuit to meet the requirements of forming a working temperature difference. Between the cooling area and the non-cooling area, the short arm combination and the long arm combination of the same type of material in the same thermocouple combination unit are connected in series by the metal guide plate, which is the series link in the thermocouple combination power supply, so that the The current and heat flow flow from the hot junction to the cold junction, forming a basic thermocouple circuit; and the cold junctions of adjacent thermocouple combination units are connected in series through the metal guide plate to form an integral thermocouple circuit and heat circuit. It realizes the characteristics of reducing resistance, reducing thermal conductivity, appropriately reducing voltage and increasing current, and keeping the total power unchanged. It is a high-efficiency thermoelectric power generation sheet for engineering applications.

specifically:

A hybrid thermoelectric power generation sheet with high thermoelectric conversion efficiency, comprising: a cold end face, a hot end face and a thermocouple combination unit located between the cold end face and the hot end face, wherein:

The cold end face is divided into a cooling area and a non-cooling area, the cooling area is in contact with the cold source, and the non-cooling area is not in contact with the cold source; the hot end face completely contacts the heat source;

The thermocouple combination unit takes the form of a combination of short thermocouple arms and a combination of long thermocouple arms to construct a parallel and series loop of thermocouples, and the thermocouple combination unit is equivalent to one or more simple thermocouples connected in parallel;

The hybrid thermoelectric power generation sheet includes a plurality of thermocouple combination units. From both sides of the center line of the hybrid thermoelectric power generation sheet, multiple rows of thermocouple combination units are longitudinally arranged, and different rows of thermocouple combination units are turned from metal to metal. The guide vanes are connected in series to form an integral thermocouple conversion circuit.

Preferably, the thermocouple combination unit takes the form of a combination of short thermocouple arms and a combination of long thermocouple arms to construct the parallel and series loops of thermocouples, specifically including: each pair of short arms of n-type material and short arms of p-type material. Connect to form two hot junctions of the thermocouple combination unit. The hot end of each pair of n-type material long arm combination and p-type material long arm combination is connected to form another hot junction of the thermocouple combination unit. The hot junction is only heated by the heat source The cold end of the long arm combination is connected with the cold end of the special-shaped material long arm combination of the adjacent unit respectively to form two cold junctions of the thermocouple combination unit, and the cold junction needs to be cooled by the cold source.

Preferably, the cold surface of the thermoelectric power generation sheet may be provided with one or more cooling areas and one or more non-cooling areas. And the smaller the cooling area and the larger the non-cooling area, the smaller the heat loss through the thermoelectric power generation sheet, and the higher the thermoelectric conversion efficiency.

Preferably, an encapsulation and heat insulation frame is provided on the periphery of the thermoelectric power generation sheet, a circuit lead-out wire joint slot is opened, an upper straight frame strip and a lower straight frame strip are arranged between the cooling area and the non-cooling area, and the upper straight frame strip and the The lower straight frame bar is made of high temperature resistant thermal insulation material. The upper straight frame is provided with a through groove and a turning groove, and the lower straight frame is an independent part, which is used together with the upper straight frame.

Preferably, the non-cooling area is covered with a thermal insulation board, the thermal insulation board is made of high temperature-resistant thermal insulation material, the top of the thermal insulation board is a stepped structure, the bottom is a plane structure, and the bottom is connected to the encapsulation thermal insulation frame and the upper straight frame. The strip and the lower straight frame strip together form the installation space for the thermal junction.

Preferably, the thermocouple arms of the thermoelectric sheet are made of different types of semiconductor materials, connected in parallel and in series, and used in combination.

Preferably, the long thermocouple arm combination and the short thermocouple arm combination of the multiple thermocouple combination units of the hybrid thermocouple power generation sheet form a thermocouple arm combination array, and the thermocouple arm combination array uses a hybrid thermocouple power generation. The center line of the sheet is used as the reference, and the thermocouple arm combinations of different types are inversely symmetrical; the thermocouple arm combinations in adjacent rows and columns are staggered.

Preferably, the thermocouple arm of the thermoelectric sheet has two heights (length), long and short, the resistance value of the short thermocouple arm is smaller than the resistance value of the long thermocouple arm, and the shorter the length of the short thermocouple arm, the better It is more beneficial to improve the thermoelectric conversion efficiency.

Preferably, the short thermocouple arm combination (short arm combination) of the thermoelectric power generation sheet is composed of short thermocouple arms of the same type of material superimposed up and down, and a metal guide plate is arranged in the middle; the long thermocouple arm combination (long arm combination) It is composed of long thermocouple arms and short thermocouple arms of the same type of material superimposed up and down, and a metal guide plate is arranged in the middle.

Preferably, the thermoelectric power generation sheet adopts metal guide sheets of two different sizes, long and short. The short metal guide piece is used to connect a pair of n-type material thermocouple arm combination and p-type material thermocouple arm combination, and the long metal guide piece is used to connect the same type of material thermocouple arm combination.

Preferably, all the thermocouple arm combinations of one thermocouple combination unit of the thermoelectric sheet are functionally arranged in the cooling area and the non-cooling area. Both the n-type material thermocouple arm combination and the p-type material thermocouple arm combination set in the cooling area are long thermocouple arm combinations, and the hot end face of the long thermocouple arm combination contacts the heat source and the cold end face contacts the cold source; Both the n-type material thermocouple arm combination and the p-type material thermocouple arm combination in the region are composed of short thermocouple arms, and the short thermocouple arm combination is only heated by the heat source and not cooled by the cold source. A combination of short thermocouple arms and a combination of long thermocouple arms of the same type of material are connected in series by long metal baffles.

Preferably, the hot end face of the hybrid thermoelectric power generation sheet is a plane, the hot junctions formed by the connection of each metal guide sheet are connected in parallel, and all the hot junctions have the same temperature. The hot end face is provided with a lower straight frame strip, which together with the encapsulated heat insulation frame and the upper straight frame strip form an installation space for a hot junction.

Preferably, a pair of short thermocouple arms of n-type material and p-type material of the thermoelectric power generation sheet are connected by short metal guide plates to form a thermal junction of a thermocouple combination unit, and a thermocouple combination unit may have a For one or more pairs of hot junctions, multiple hot junctions are connected in parallel. The number of thermal junctions and the size of the short thermocouple arm determine the output current value of the thermoelectric sheet.

Preferably, a pair of n-type material of the thermoelectric sheet is combined with long thermocouple arms of p-type material, and their hot ends are heated by the heat source, and the cold ends are cooled by the cold source. There can be one or more pairs of long thermocouple arm combinations in one thermocouple combination unit, and the long thermocouple arm combinations of the same material are connected in parallel. The cold ends of a pair of long thermocouple arm combinations of special-shaped materials belonging to adjacent thermocouple combination units are connected by short metal guide plates to form a cold junction of a thermocouple combination unit, and the cold junctions are connected in series. The number of cold junctions connected in series and the size of the long thermocouple arm determine the output voltage value of the thermoelectric sheet. Preferably, on both sides of the center line of the thermoelectric power generation sheet, thermocouple combination unit arrays are arranged longitudinally on each side, the thermocouple combination units in the same row are connected in series by short-steering metal guide strips, and the thermocouple combination units in different columns are long-steering metal The baffles or short turning metal baffles are connected in series.

Preferably, the thermoelectric power generation sheet adopts a turning metal guide sheet of two different sizes, long and short. The long turning metal guide piece connects the long thermocouple arm combinations of the special-shaped materials in the adjacent thermocouple combination unit columns; the short turning metal guide piece connects the adjacent special-shaped materials in the adjacent thermocouple combination unit column. combination of long thermocouple arms. The connection of the two kinds of steering metal guide plates forms a cold junction, and connects the multi-column thermocouple combination units into an integral thermoelectric conversion circuit.

Preferably, the cold surface of the thermoelectric power generation sheet may be covered with an insulating plate, and the hot surface may also be covered with an insulating plate.

Preferably, the thermoelectric power generation sheet technology can also be used for the design of thermoelectric cooling sheets.

Compared with the prior art, the present invention has the following advantages:

(1) The applicant found that: from the aspect of structural design, the direction of improving the conversion efficiency of the thermoelectric power generation sheet is: reducing the total resistance of the thermocouple array to reduce the loss of output power, and simultaneously reducing the thermal conductivity through the thermocouple arm to reduce heat. loss. Therefore, based on the existing thermoelectric materials, the present invention changes the circuit and thermal circuit structure design of the thermoelectric power generation sheet, which is of great significance for improving the thermoelectric conversion efficiency of the thermoelectric power generation sheet.

(2) A cooling area and a non-cooling area are arranged on the cold surface of the thermoelectric sheet, wherein: the thermocouple arms in the non-cooling area do not need to be cooled, which greatly reduces the heat loss caused by heat conduction.

(3) The combination of long and short lengths of thermocouple arms and the metal guide plates of long and short lengths are used to construct a multi-contact hybrid thermocouple combination unit with synergistic circuit and thermal circuit, which increases the number of thermal contacts. The number of junctions and the number of cold junctions are reduced, the total resistance is reduced, and the thermoelectric conversion efficiency is significantly improved.

(4) The output voltage of the thermoelectric power generation sheet decreases reasonably, but the output current increases accordingly, the total output power remains unchanged, and has good output power characteristics.

Description of drawings

FIG. 1 is a structural diagram (a perspective view, a cold surface view) of a thermoelectric power generation sheet in an embodiment of the present invention.

FIG. 2 is an arrangement diagram (cold surface view) of a thermocouple arm combination array of a thermoelectric power generation sheet in an embodiment of the present invention.

FIG. 3 is a structural diagram (perspective view) of a thermocouple combination unit of a thermoelectric power generation sheet in an embodiment of the present invention.

FIG. 4 is a cold side connection diagram (cold side view) of a thermoelectric power generation sheet in an embodiment of the present invention.

FIG. 5 is a thermal surface connection diagram (thermal surface view) of a thermoelectric power generation sheet in an embodiment of the present invention.

FIG. 6 is a block diagram (cold side view) of encapsulation and heat insulation of a thermoelectric power generation sheet in an embodiment of the present invention.

Among them: A, the cooling area of the thermoelectric sheet (area A); B, the non-cooling area of the thermoelectric sheet (area B); L (row number, column number), thermocouple arm combination number; C (row number, column number) No.), thermocouple arm combination unit number; E, thermocouple combination unit; N (row number, column number), cold surface guide plate number; M (row number, column number), hot surface guide plate number; t _{0. The} center line of the thermoelectric power generation sheet; 1. The circuit lead-out wire connector (positive pole); 2. The circuit lead-out wire connector (negative pole); 3. The cold surface heat insulation board; Even arm (n-type long arm); 6. Short thermocouple arm of n-type material (n-type short arm); 7. Long thermocouple arm of p-type material (p-type long arm); 8. Short thermocouple arm of p-type material (p-type short arm); 9. Long metal guide plate; 10. Short metal guide plate; 11. Long turning metal guide plate; 12. Short turning metal guide plate; 13. Circuit lead wire joint slot; 14 , Upper straight frame strip; 15, through slot; 16, steering slot; 17, lower straight frame strip.

detailed description

The present invention will be further described below with reference to the accompanying drawings and examples, but the embodiments of the present invention are not limited thereto.

Figure 1 shows the cold side view of the thermoelectric sheet structure. Among them, the upper end face of the thermoelectric power generation sheet is its cold face, and the cold face is the working face that directly contacts the cold source and is cooled. The cold surface is symmetrically divided into seven areas based on the centerline t ₀ of the thermoelectric power generation sheet (as shown in Figure 2): four cooling areas A and three non-cooling areas B, the total area of the cooling area A and the non-cooling area B The total area of is equal, and only the cooling area A can be in contact with the cold source, that is, only 1/2 of the cold surface area can be cooled. The non-cooling area B is covered with a cold surface heat insulation board 3, the upper surface of the cold surface heat insulation board 3 is a stepped structure, the position of the long turning metal guide fin 11 is a low stepped surface, and the cold surface heat insulation board 3 The high step surface is flush with the cold surface of the thermoelectric sheet. The cold surface insulation board 3 is made of heat-insulating and insulating materials, such as foam materials, fiber materials, and vacuum materials. short circuit. The encapsulating heat-insulating frame 4 is also made of heat-insulating and insulating material (as shown in FIG. 6 ), and is enclosed around the thermoelectric sheet. The upper straight frame strip 14 and the lower straight frame strip 17 are used to separate the area A and the area B, and cooperate with the cold surface heat insulation board 3 to play the role of isolating the area B. The positive pole 1 and the negative pole 2 of the circuit lead-out connector are connected to the external circuit, and output DC current when working. When the thermoelectric sheet is working, an insulating plate can be set on the cold surface. The insulating plate is made of ceramic plate or other high-temperature-resistant insulating materials, so that the cold junction can be fully cooled, and the direct contact between the metal guide plate and the cold source is avoided. cause a current short circuit.

The combination of the n-type long arm 5 and the p-type long arm 7 is arranged in the area A, each of which is made of the same type of semiconductor material. A long arm and a short arm are welded on the upper and lower sides of the long metal guide plate 9 , and connect their short arm hot end faces by short metal guide plates 10 to form a hot junction of the thermocouple combination unit (as shown in FIG. 3 ). A combination of n-type short arms 6 and p-type short arms 8 are arranged in region B, and they are each made of two short arms made of the same type of semiconductor material welded on the upper and lower sides of the long metal guide plate 9, and The hot end faces of two short arms of different types of semiconductor materials in adjacent rows are respectively connected by short metal guide plates 10 to form the other two hot junctions of the thermocouple combination unit (as shown in Figure 3); During this time, the long metal guide fins 9 pass through the area A and the area B, and connect the hot end faces of the same type of material arms located in the same row (as shown in FIG. 3 ). The function of the long-steering metal guide fins 11 and the short-turning metal guide fins 12 is to connect the thermocouple combination units of different columns in series (as shown in FIG. 4 ) to form an integral thermocouple conversion circuit.

The lower end surface of Figure 1 is the hot surface of the thermoelectric power generation sheet. During operation, the entire surface area of the hot surface is heated by the heat source and absorbs the heat of the heat source. The hot surface can also be covered with an insulating plate, so that sufficient heat transfer can be performed between the hot surface and the heat source, and at the same time, the direct contact between the metal guide fin and the heat source can be avoided to cause a short circuit of current.

FIG. 2 shows an example (cold side view) of the arrangement structure of the thermocouple arm combination array of the thermoelectric sheet. The thermocouple arm array in the figure is 12 rows by 12 columns, composed of 72 thermocouple arm combinations of n-type materials and 72 thermocouple arms combinations of p-type materials. where each rectangle represents a combination of thermocouple arms with a rectangular cross-section, and the same color indicates that they are made of the same type of semiconductor material. The number of the thermocouple arm combination is represented by the symbol L (row number, column number), for example, L(1, 1) represents the thermocouple arm combination located in the first row and the first column. In the array, a combination of a pair of long thermocouple arms of special-shaped material and a combination of a pair of short thermocouple arms of special-shaped material constitute a thermocouple arm combination unit C, wherein the combination of two thermocouple arms in the same row The material type of the 2 thermocouple arm combination of the row is reversed. The symbols I∽VI represent 6 rows and 6 columns arranged in sequence, a total of 36 thermocouple arm combination units C, and their numbering method is C (row number, column number). For example, C(IV, VI) represents a thermocouple arm combination unit located in the 4th row and the 6th column, consisting of L(7,11), L(7,12), L(8,11) and L(8,12 )composition.

A combination of n-type long arms 5 and a combination of p-type long arms 7 are arranged in region A, and they are both formed by superimposing a long arm and a short arm of the same material on top of each other (as shown in Figures 1 and 3). The short thermocouple arms set in area B include the combination of n-type short arms 6 and p-type short arms 8, which are formed by superimposing two short arms of the same material on top of each other (as shown in Figures 1 and 1). shown in Figure 3). Figure 3, Figure 4 and Figure 5 show how the thermocouple arm assembly is connected.

Figure 3 shows the structure and connection method of a multi-contact hybrid thermocouple combination unit E of the thermoelectric power generation sheet. )) and metal guide vanes. Wherein: the reference numeral 5 is the n-type long arm, 6 is the n-type short arm, 7 is the p-type long arm, and 8 is the p-type short arm. As shown in Figure 1 and Figure 2: In the area A, the long arm combination is constructed as follows: L(7, 12) is welded by the n-type long arm 5 and the n-type short arm 6 on the upper and lower sides of the long metal guide plate 9 On both sides, L(8, 12) is welded on the upper and lower sides of the long metal guide plate 9 by the p-type long arm 7 and the p-type short arm 8. In the region B, the short arm combination is composed as follows: L(7, 11) is composed of two n-type short arms 6 welded to the upper and lower sides of the long metal guide fin 9, and L(8, 11) is composed of two p-type short arms 6. The short arm 8 is welded on the upper and lower sides of the long metal guide vane 9 .

Connection options for thermocouple arm assemblies include:

(1) In area A, the long arm combinations L(7, 12) and L(8, 12) of two adjacent rows are included, and their n-type short arms 6 (not shown) and p-type short arms 8 are composed of The short metal guide plates 10 numbered M(4, 12) are connected to form a hot junction; and the two cold junctions are respectively formed by connecting the long arms and the long arms of the special-shaped material corresponding to the adjacent thermocouple arm combination unit C. , such as the cold end face of the n-type long arm 5 of L(7, 12), through the short metal guide plate N(3, 12), and the p-type long arm of the adjacent thermocouple arm combination unit C combined L(6, 12) Connect (as shown in Figure 2) to form a cold junction; similarly, the cold end face of the p-type long arm 7 numbered L(8, 12) passes through the short metal guide plate N(4, 12) The second cold junction is formed by connecting with the cold end face of the n-type long arm combination L(9, 12) (as shown in Figure 2). The two cold junctions are connected in series.

(2) Area B includes two adjacent rows of short arm combinations L(7, 11) and L(8, 11), whose upper and lower end faces are hot end faces, respectively numbered M(4, 11) The short metal guide plates 10 are connected to form two upper and lower thermal junctions. The two hot junctions are connected in parallel.

(3) Between the area A and the area B, the long thermocouple arm combination and the short thermocouple arm combination of the same type of material are laterally connected in series by the long metal guide plate 9, such as the n-type long arm numbered L(7, 12). The combination and the n-type short arm combination numbered L(7, 11) are connected in series by the long metal guide plate 9; the p-type long arm combination numbered L(8, 12) and the number L(8, 11) are connected in series The p-type short arm combination is connected in series by long metal guide plates 9 . At the same time, due to the connection effect of the long metal guide plates 9, the three thermal junctions in the area A and the area B are connected in parallel.

Figure 3 shows a thermocouple combination unit E. The three hot junctions in E are connected in parallel, and the two cold junctions are connected in series, which is equivalent to the parallel connection of three simple thermocouples, which is a more compact miniature thermoelectric power supply.

Fig. 4 is a diagram showing the connection of the cold side of the thermoelectric power generation sheet, showing the way in which all the thermocouple combination units are connected to form a thermoelectric conversion circuit. Among them: the symbol I∽VI represents the six thermocouple arm combination units C arranged in sequence (as shown in Figure 2). The symbol E represents a thermocouple combination unit, and the thermocouple arm combination unit belonging to it is marked C(IV, VI) in FIG. 2 , and the connection mode of its thermocouple arms is shown in FIG. 3 . Each thermocouple combination unit E contains 6 short arms and 2 long arms. Among them, as shown in Figure 2: the n-type long arm combination numbered L(7, 12) is connected to the p-type long arm combination L(6, 12) through the short metal guide plate N(3, 12), and the number is The p-type long arm combination of L(8, 12) is connected to the n-type long arm combination L(9, 12) through the short metal guide plate N(4, 12). Similarly, the long arms of the special-shaped material in the adjacent thermocouple arm combination units C are connected in series to form the thermocouple combination units E through the connection of the short metal guide plates 10 .

This thermoelectric power generation sheet has a total of 6 rows of thermocouple combination units E, and the thermocouple circuit turns from positive 1 to negative 2 5 times. Therefore, each row of thermocouple combination units E needs to be connected in series by turning metal guide plates to form An integral thermoelectric conversion circuit. At the same time, as shown in Figures 1 and 2: the long thermocouple arm combination L(12, 12) of P-type material located in the area A of the VI column, through the long turning metal guide plate 11, is located in the area A of the V column. The n-type material in the long thermocouple arm combination L(12, 9) is connected in series to form a cold junction. The long-steering metal deflector 11 crosses the non-cooling area B from the top of the short arm combination, and there is a cold surface heat insulation plate 3 between them to isolate them without contact; the P-type material long thermocouple arm combination L (12 , 8), is also connected in series with the n-type material long thermocouple arm combination L(12, 5) located in the area A of the third column through the long turning metal guide plate 11 to form another cold junction. In the same way, the long arm combination of the second column and the long arm combination of the special-shaped material in the first column in the area A are also connected in series through the long steering metal guide fins 11 to form a cold junction; The long arms of the column located in the area A are adjacent to each other, and they are connected in series by the short steering metal guide fins 12 to form a cold junction; similarly, the long arms located in the third column and the second column are located in the area A. The combination is adjacent, and short-steering metal guide fins 12 are also connected in series between them. Thus, the positive terminal 1 of the circuit lead-out wire is connected to the negative terminal 2 of the circuit lead-out wire through the combination of all the thermocouple arms to form a complete thermocouple circuit.

Fig. 5 is a connection diagram of the thermal surface of the thermoelectric power generation sheet, the hot surface is the end surface heated by the heat source when the thermoelectric power generation sheet is working. Fig. 5 is a rear view of Fig. 4, and reference numerals I∽VI designate the same thermocouple arm combination unit C as in Fig. 4 . The thermocouple combination unit E shown in FIG. 5 is the same as that shown in FIG. 4 , its thermocouple arm combination unit is labeled C(IV, VI) in FIG. 2 , and its thermocouple arm connection is shown in FIG. 3 . The thermal surface connection view of the thermocouple combination unit E shows that the short metal guide plates M(4, 11) are connected to the lower short arms of L(8, 11) and L(7, 11), M(4, 12) ) is connected to the lower short arms of L(8, 12) and L(7, 12) (as shown in Figure 3). In the same way, the 36 thermocouple combination units E of this example of the thermoelectric power generation sheet have the same hot surface connection method to ensure that the hot junctions of each thermocouple arm combination have the same temperature. The hot surface position of the lower straight frame strip 17 is matched with the upper straight frame strip 14 to separate the area A and the area B. The upper straight frame strip 14 is provided with a through groove 15 (as shown in FIG. 6 ), and a long metal guide plate is formed. 9 can pass through slot 15 and be compressed.

Fig. 6 shows the encapsulation heat insulation frame 4 (cold side view) of the thermoelectric power generation sheet. The encapsulation heat insulation frame 4 is made of high temperature resistant heat insulation material. There are 4 cooling areas A and 3 non-cooling areas B in the frame. The six upper straight frame bars 14 and the six lower straight frame bars 17 separate the area A and the area B (as shown in FIG. 1 ). Eleven through grooves 15 are formed at the bottom of each upper straight frame bar 14 , and the long metal guide pieces 9 can pass through the through grooves 15 . The lower straight frame bar 17 is an independent component, and cooperates with the upper straight frame bar 14 to press the long metal guide plate 9 . The turning groove 16 is flush with the stepped surface of the cold-surface heat insulation board 3, so that the long turning metal guide fins 11 are flush with the upper plane of the cold-surface heat insulation board 3 (as shown in FIG. 1). The area B is covered with a cold surface heat insulation board 3 to form an isolated thermal space (as shown in Figure 1), in which the thermal junction is heated uniformly, and there is no temperature gradient during steady-state operation. The outer frame of the encapsulated heat insulation frame 4 plays a role of fixing and protecting the thermoelectric power generation sheet. The circuit lead-out wire connector slot 13 is used as an outlet, and is connected with the external circuit in conjunction with the positive pole 1 and the negative pole 2 of the circuit lead-out wire connector.

Compared with the existing 12×12 thermoelectric power generation sheet, the cooling area of the example of the present invention is reduced by 1/2, the heat loss is correspondingly reduced by 1/2, and the efficiency of thermoelectric conversion is nearly doubled. The thermoelectric power generation sheet has 36 thermocouple combination units E connected in series, and each thermocouple combination unit E is equivalent to three simple thermocouples connected in parallel. When the thermoelectric material and cross-sectional area remain unchanged, and satisfy: the height of the short thermocouple arm is less than or equal to 1/4 of the height of the long thermocouple arm, the output voltage of the power generating sheet is reduced by 1/2, but the output current is doubled, making the total output The power value remains unchanged.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims

A hybrid thermoelectric power generation sheet with high thermoelectric conversion efficiency, characterized in that the hybrid thermoelectric power generation sheet comprises: a cold end face, a hot end face and a thermocouple combination unit located between the cold end face and the hot end face, wherein:

The cold end face is divided into a cooling area and a non-cooling area, the cooling area is in contact with the cold source, and the non-cooling area is not in contact with the cold source; the hot end face completely contacts the heat source;

The thermocouple combination unit takes the form of a combination of short thermocouple arms and a combination of long thermocouple arms to construct a parallel and series loop of thermocouples, and the thermocouple combination unit is equivalent to one or more simple thermocouples connected in parallel;

The hybrid thermoelectric power generation sheet includes a plurality of thermocouple combination units, and multiple rows of thermocouple combination units are longitudinally arranged on both sides of the center line of the hybrid thermoelectric power generation sheet. The tapes are connected in series to form an integral thermocouple conversion circuit.
The hybrid thermoelectric power generation sheet according to claim 1, wherein the thermocouple combination unit adopts the form of a combination of short thermocouple arms and a combination of long thermocouple arms to construct a series and parallel loop of thermocouples, specifically including: each The n-type material short thermocouple arm combination and the p-type material short thermocouple arm combination are connected to form two thermal junctions of the thermocouple combination unit, each pair of n-type material long thermocouple arm combination and p-type material long thermocouple The hot end of the arm combination is connected to form another hot junction of the thermocouple combination unit. The hot junction is only heated by the heat source and does not need to be cooled by the cold source, so it has the same temperature; while the cold end of the long thermocouple arm combination is connected to the adjacent unit respectively. The cold ends of the special-shaped material long thermocouple arm combination are connected to form two cold junctions of the thermocouple combination unit, and the cold junction needs to be cooled by the cold source.
The hybrid thermoelectric power generation sheet according to claim 2, wherein one thermocouple combination unit has one or more pairs of thermal junctions, and the thermal junctions are connected in parallel; the number of thermal junctions and the size of the short thermocouple arm , which determines the output current value of the thermoelectric generator.
The hybrid thermoelectric power generation sheet according to claim 1, wherein the short thermocouple arm combination is composed of short thermocouple arms of the same type of material superimposed on top of each other, and a metal guide sheet is arranged in the middle; The pair arm combination is composed of a long thermocouple arm and a short thermocouple arm of the same type of material superimposed up and down, and a metal guide plate is arranged in the middle.
The hybrid thermoelectric power generation sheet according to claim 1, wherein all the thermocouple arm combinations of the thermocouple combination unit are arranged in the cooling area and the non-cooling area according to their functions; the thermocouples arranged in the cooling area The arm combinations are all long thermocouple arm combinations, the hot end face of the long thermocouple arm combination is in contact with the heat source, and the cold end face is in contact with the cold source; the thermocouple arm combinations set in the non-cooling area are all short thermocouple arm combinations, short thermocouple arms The combination is only heated by the heat source, not cooled by the cold source; the short thermocouple arm combination and the long thermocouple arm combination of the same type of material are connected in series by long metal guide plates.
The hybrid thermoelectric power generation sheet according to claim 1, characterized in that, the thermoelectric power generation sheet adopts two different sizes of turning metal guide fins, long and short; the long turning metal guide fins are connected to adjacent thermocouples Combination of long thermocouple arms of special-shaped materials spaced apart in the combined unit row; the short turning metal guide plate connects the adjacent long thermocouple arms of special-shaped materials in the row of adjacent thermocouple combination units; two kinds of turning The connections of the metal guide plates all form cold junctions, and connect multiple columns of thermocouple combination units to form an integral thermoelectric conversion circuit.
The hybrid thermoelectric power generation sheet according to claim 1, wherein the cold end face of the hybrid thermoelectric power generation sheet is provided with one or more cooling areas and one or more non-cooling areas; and the cooling area The smaller and the larger the non-cooling area, the smaller the heat loss through the hybrid thermoelectric power generation sheet, and the higher the thermoelectric conversion efficiency.
The hybrid thermoelectric power generation sheet according to claim 1, wherein the non-cooling area is covered with a heat insulating plate, and the heat insulating plate is made of a high temperature resistant heat insulating material; the upper surface of the heat insulating plate is a stepped structure, Below is the flat structure, below which together with the encapsulated thermal insulation frame and the upper and lower straight frame strips form the installation space for the thermal junction.
The hybrid thermoelectric power generation sheet according to claim 1, wherein the hot end face of the hybrid thermoelectric power generation sheet is a plane, and the hot junctions formed by the connection of each metal guide sheet are connected in parallel, and all the The temperature of the hot junction is the same; the hot end face is provided with a lower straight frame strip, which forms the installation space of the hot junction together with the encapsulated heat insulation frame and the upper straight frame strip.
The hybrid thermoelectric power generation sheet according to claim 1, characterized in that, the outer periphery of the hybrid thermoelectric power generation sheet is provided with an encapsulation and heat insulation frame, and a circuit lead-out wire joint slot is opened, and the cooling area and the non-cooling area are provided in the cooling area and non-cooling area. There is an upper straight frame strip and a lower straight frame strip between them, and the upper straight frame strip and the lower straight frame strip are made of high-temperature-resistant thermal insulation materials; the upper straight frame strip has a through groove and a turning groove, and the lower straight frame strip is an independent part , used together with the upper straight frame.
The hybrid thermoelectric power generation sheet according to claim 2, wherein one thermocouple combination unit has one or more pairs of long thermocouple arm combinations, and the long thermocouple arm combinations of the same type of material are connected in parallel; The cold ends of a pair of long thermocouple arms of special-shaped materials of the thermocouple combination unit are connected by short metal guide plates to form a cold junction of the thermocouple combination unit, and the cold junctions are connected in series; the number of cold junctions connected in series and The size of the long thermocouple arm determines the output voltage value of the thermoelectric sheet.
The hybrid thermoelectric power generation sheet according to claim 4, wherein the resistance value of the short thermocouple arm of the hybrid thermoelectric power generation sheet is smaller than the resistance value of the long thermocouple arm, and the length of the short thermocouple arm The shorter it is, the more beneficial it is to improve the thermoelectric conversion efficiency.
The hybrid thermoelectric power generation sheet according to claim 1, wherein the long thermocouple arm combination and the short thermocouple arm combination of the multiple thermocouple combination units of the hybrid thermoelectric power generation sheet form a thermocouple arm combination The thermocouple arm combination array is based on the center line of the hybrid thermoelectric generation sheet, and the thermocouple arm combinations of different types are inversely symmetrical; the thermocouple arm combinations in adjacent rows and columns are staggered.
The hybrid thermoelectric power generation sheet according to claim 4, characterized in that, the hybrid thermoelectric power generation sheet adopts two different sizes of metal guide fins, long and short; the short metal guide fin is used to connect a pair of The n-type material thermocouple arm combination and the p-type material thermocouple arm combination, and the long metal guide plate is used to connect the thermocouple arm combination of the same type of material.
The hybrid thermoelectric power generation sheet according to claim 1, wherein the cold end face or/and the hot end face of the hybrid thermoelectric power generation sheet is covered with an insulating plate.
The hybrid thermoelectric power generation sheet according to claim 1, characterized in that, the hybrid thermoelectric power generation sheet is also used for the design of a thermoelectric cooling sheet.