A variable angle annular thermoelectric device

Abstract

The invention discloses a variable-angle annular thermoelectric device, which relates to the field of thermoelectrics. The variable-angle annular thermoelectric device comprises: an upper insulating substrate, which is used to isolate the current of an upper conductive sheet; a lower insulating substrate, which is used to isolate the current of a lower conductive sheet and sense heat flow; an upper conductive sheet, which is used to conduct electricity; a lower conductive sheet, which is used to conduct electricity; and a P-type thermoelectric semiconductor, which is used to form current through a temperature difference. Compared with the prior art, the invention has the following beneficial effects: the invention provides a variable-angle annular thermoelectric device, which can perfectly fit a circular heat source, thereby improving its thermal energy utilization rate; the central angle of the thermoelectric semiconductor in the annular thermoelectric device increases continuously along the heat flow direction, and the central angle of each column of thermoelectric semiconductors is solved by the working temperature of each column of thermoelectric semiconductors, thereby finally achieving the same current output of thermoelectric semiconductors in different columns, overcoming power loss, improving its output power, and promoting the development of thermoelectric devices.

Description

Technical Field

[0001] The invention relates to the field of thermoelectricity, in particular to a variable-angle annular thermoelectric device. Background Art

[0002] As a new energy technology, thermoelectric conversion technology is based on the Seebeck effect of semiconductors. It uses the temperature difference potential energy at both ends of the semiconductor to drive the directional movement of carriers inside the semiconductor to generate current, and can directly convert thermal energy into electrical energy. It has a wide range of application scenarios, such as converting the thermal energy of radioactive elements into electrical energy to power spacecraft, converting human body temperature into electrical energy for wearable devices, and self-powered sensors in the field of the Internet of Things. As the core unit of thermoelectric conversion technology, the hot end of the thermoelectric device is directly attached to the surface of the heat source, and a heat dissipation device is designed at the other end to achieve the conversion of thermal energy to electrical energy. However, the surface of some heat sources is not a plane. For example, high-temperature exhaust gas and industrial high-temperature wastewater are often discharged through pipes, and the heat source surface is circular. Traditional planar thermoelectric devices cannot fit perfectly with the circular surface, resulting in low thermal energy utilization. Therefore, annular thermoelectric devices have more advantages in utilizing heat sources on circular surfaces.

[0003] When annular thermoelectric devices are used to recover waste heat from fluids such as engine exhaust and industrial wastewater, as the fluid flows downward, the fluid temperature will continue to decrease, causing the hot end operating temperature of the annular thermoelectric device to also decrease, making the output current of the thermoelectric semiconductor in the downward direction of the fluid lower.

[0004] However, since all the thermoelectric semiconductors inside the thermoelectric device are connected in series, the overall output current of the thermoelectric device is equal to the minimum output current inside the thermoelectric semiconductor, resulting in power loss. In order to reduce the loss of power, researchers have proposed various solutions, such as using gradient thermoelectric materials along the direction of heat flow, using high-temperature thermoelectric materials in the high-temperature zone and low-temperature thermoelectric materials in the low-temperature zone, to overcome this problem based on the characteristics of thermoelectric materials. However, the high-temperature zone or low-temperature zone contains many columns of thermoelectric semiconductors, and there is still power loss in the same temperature zone, which needs to be improved. Summary of the invention

[0005] The object of the present invention is to provide a variable-angle annular thermoelectric device to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A variable-angle annular thermoelectric device, comprising:

[0008] An upper insulating substrate is used to isolate the current of the upper conductive sheet;

[0009] The lower insulating substrate is used to isolate the current of the lower conductive sheet and sense the heat flow;

[0010] The upper conductive sheet is used for conducting electricity;

[0011] The lower end conductive sheet is used for conducting electricity;

[0012] A P-type thermoelectric semiconductor, used to generate an electric current through a temperature difference between an end close to a lower insulating substrate and an end close to an upper insulating substrate;

[0013] An N-type thermoelectric semiconductor used to generate an electric current through a temperature difference between an end close to a lower insulating substrate and an end close to an upper insulating substrate;

[0014] The upper insulating substrate, the lower insulating substrate, the upper conductive sheet, the lower conductive sheet, the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are all arc-shaped structures, the heat flow flows on the side of the lower insulating substrate away from the upper insulating substrate, the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are connected in series through the upper conductive sheet and the lower conductive sheet, and are sandwiched between the upper insulating substrate and the lower insulating substrate, and the geometric parameters of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are the same; the inner radii of the lower insulating substrate, the lower conductive sheet, the thermoelectric semiconductor, the upper conductive sheet and the upper insulating substrate are R1, R2, R3, R4 and R5 respectively, and the outer radius of the upper insulating substrate is R6; the number of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor is equal, both are n (n=1,2,3,...), the number of the lower conductive sheet and the upper conductive sheet is equal, both are n / 2;

[0015] The variable angle annular thermoelectric device is divided into M (M=1, 2, 3, ...) columns along the heat flow direction, the first column is close to the heat flow inlet, the Mth column is close to the heat flow outlet, and the central angle of the thermoelectric semiconductor in the i-th column (including P-type thermoelectric semiconductors and N-type thermoelectric semiconductors) is θ i , 1≤i≤M, the center angle between the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor in the first column is α, the center angles of the upper conductive sheet and the lower conductive sheet are equal, which is 2θ1+α, and the center angles of the upper insulating substrate and the lower insulating substrate are equal, which are 2n×θ1+(2n+1)α;

[0016] The variable-angle annular thermoelectric device also includes a calculation method, step 1, setting the range of the central angle difference Δθ of thermoelectric semiconductors in adjacent columns; step 2, calculating the temperature relationship between the central angles of thermoelectric semiconductors in adjacent columns; step 3, calculating the average temperature Ti of the hot end of the thermoelectric semiconductor; step 4, calculating the relationship between the central angle difference Δθ of thermoelectric semiconductors in adjacent columns and the heat flow temperature; step 5, calculating the central angle of each column of thermoelectric semiconductors.

[0017] As a further solution of the present invention: in step 1: the central angle of the thermoelectric semiconductor in the i+1th column is greater than the central angle of the thermoelectric semiconductor in the ith column by Δθ, that is, θ i+1 =θ i +Δθ, where Δθ satisfies the relationship: (M-1)Δθ<α / 2, and θ1 is a known condition.

[0018] As a further solution of the present invention: in step 2: the output current of the thermoelectric semiconductor in the i-th column is equal to the output current of the thermoelectric semiconductor in the i+1-th column, and the temperature relationship between the central angle of the thermoelectric semiconductor in the i-th column and the central angle of the thermoelectric semiconductor in the i+1-th column is calculated, that is, the equation is satisfied: in is the average temperature of the hot end of the thermoelectric semiconductor in the i-th column, is the average temperature of the hot end of the thermoelectric semiconductor in the i+1th row, T c is the cold end temperature of the ring thermoelectric device.

[0019] As a further solution of the present invention: In step 3: the average temperature of the hot end of the thermoelectric semiconductor in the i-th column is Equal to the heat flow inlet temperature of the i-th row of thermoelectric semiconductors and the heat flow inlet temperature of the i+1th row of thermoelectric semiconductors The average value of satisfies the equation: Among them, T in and T out are the temperatures of the heat flow inlet and heat flow outlet, respectively, and both are known conditions.

[0020] As a further solution of the present invention: in step 4: calculate the relationship between Δθ and the heat flow temperature, that is, satisfy the equation: Let i = 1, and solve for:

[0021] As a further solution of the present invention: In step 5: calculate the central angle of each row of thermoelectric semiconductors, i.e., θ i =θ1+Δθ(i-1).

[0022] As a further solution of the present invention: the thickness of the lower insulating substrate is the same as the thickness of the upper insulating substrate, that is, R2-R1=R6-R5, the thickness of the lower conductive sheet is the same as the thickness of the upper conductive sheet, that is, R3-R2=R5-R4, and the thickness of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are both R4-R3.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides a variable-angle annular thermoelectric device, which can perfectly fit with a circular heat source to improve its thermal energy utilization rate; the central angle of the thermoelectric semiconductor in the annular thermoelectric device continuously increases along the heat flow direction, and the central angle of each column of thermoelectric semiconductors is solved by the operating temperature of each column, and finally the same current output of different columns of thermoelectric semiconductors is achieved, thereby overcoming power loss, improving its output power, and promoting the development of thermoelectric devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the axial structure of a variable-angle annular thermoelectric device.

[0025] Figure 2 Schematic diagram of the structure of a variable-angle annular thermoelectric device along the direction of heat flow.

[0026] In the figure: 1-upper end insulating substrate, 2-lower end insulating substrate, 3-upper end conductive sheet, 4-lower end conductive sheet, 5-P type thermoelectric semiconductor, 6-N type thermoelectric semiconductor. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] See also Figure 1 and Figure 2 , a variable angle annular thermoelectric device, comprising:

[0029] The upper insulating substrate 1 is used to isolate the current of the upper conductive sheet 3;

[0030] The lower insulating substrate 2 is used to isolate the current of the lower conductive sheet 4 and sense the heat flow;

[0031] The upper conductive sheet 3 is used for conducting electricity;

[0032] The lower end conductive sheet 4 is used for conducting electricity;

[0033] A P-type thermoelectric semiconductor 5, used to form an electric current through a temperature difference between an end close to the lower insulating substrate 2 and an end close to the upper insulating substrate 1;

[0034] N-type thermoelectric semiconductor 6, used to generate current through the temperature difference between one end close to the lower insulating substrate 2 and one end close to the upper insulating substrate 1;

[0035] The upper insulating substrate 1, the lower insulating substrate 2, the upper conductive sheet 3, the lower conductive sheet 4, the P-type thermoelectric semiconductor 5 and the N-type thermoelectric semiconductor 6 are all arc-shaped structures, the heat flow flows on the side of the lower insulating substrate 2 away from the upper insulating substrate 1, the P-type thermoelectric semiconductor 5 and the N-type thermoelectric semiconductor 6 are connected in series through the upper conductive sheet 3 and the lower conductive sheet 4, and are sandwiched between the upper insulating substrate 1 and the lower insulating substrate 2, and the geometric parameters of the P-type thermoelectric semiconductor 5 and the N-type thermoelectric semiconductor 6 are the same; the inner radii of the lower insulating substrate 2, the lower conductive sheet 4, the thermoelectric semiconductor, the upper conductive sheet 3 and the upper insulating substrate 1 are R1, R2, R3, R4 and R5 respectively, and the outer radius of the upper insulating substrate 1 is R6; the number of the P-type thermoelectric semiconductor 5 and the N-type thermoelectric semiconductor 6 is equal, both are n (n=1, 2, 3, ...), the number of the lower conductive sheet 4 and the upper conductive sheet 3 is equal, both are n / 2;

[0036] The variable angle annular thermoelectric device is divided into M (M=1, 2, 3, ...) columns along the heat flow direction, the first column is close to the heat flow inlet, the Mth column is close to the heat flow outlet, and the central angle of the thermoelectric semiconductor in the i-th column (the angle between adjacent P-type thermoelectric semiconductors 5 and N-type thermoelectric semiconductors 6) is θ i , 1≤i≤M, the center angle between the P-type thermoelectric semiconductor 5 and the N-type thermoelectric semiconductor 6 in the first column is α, the center angles of the upper conductive sheet 3 and the lower conductive sheet 4 are equal, which is 2θ1+α, and the center angles of the upper insulating substrate 1 and the lower insulating substrate 2 are equal, which are 2n×θ1+(2n+1)α;

[0037] The variable angle annular thermoelectric device also includes a calculation method, step 1, setting the range of the central angle difference Δθ of the thermoelectric semiconductors in adjacent columns; step 2, calculating the temperature relationship between the central angles of the thermoelectric semiconductors in adjacent columns; step 3, calculating the average temperature of the hot end of the thermoelectric semiconductor Step 4, calculating the relationship between the central angle difference Δθ of thermoelectric semiconductors in adjacent columns and the heat flow temperature; Step 5, calculating the central angle of each column of thermoelectric semiconductors.

[0038] In this embodiment: the thickness of the lower insulating substrate 2 is the same as the thickness of the upper insulating substrate 1, that is, R2-R1=R6-R5, the thickness of the lower conductive sheet 4 is the same as the thickness of the upper conductive sheet 3, that is, R3-R2=R5-R4, and the thickness of the P-type thermoelectric semiconductor 5 and the N-type thermoelectric semiconductor 6 are both R4-R3.

[0039] The specific implementation steps for calculating the central angle of each column of thermoelectric semiconductors are as follows:

[0040] Step 1: Let the central angle of the thermoelectric semiconductor in the i+1th column be Δθ greater than the central angle of the thermoelectric semiconductor in the ith column, that is, θ i+1 =θ i+Δθ, where Δθ satisfies the relationship: (M-1)Δθ<α / 2, and θ1 is a known condition.

[0041] Step 2, let the output current of the thermoelectric semiconductor in the i-th column be equal to the output current of the thermoelectric semiconductor in the i+1th column, and calculate the temperature relationship between the central angle of the thermoelectric semiconductor in the i-th column and the central angle of the thermoelectric semiconductor in the i+1th column, that is, satisfy the equation: in is the average temperature of the hot end of the thermoelectric semiconductor in the i-th column, is the average temperature of the hot end of the thermoelectric semiconductor in the i+1th row, T c is the cold end temperature of the ring thermoelectric device.

[0042] Step 3, the average temperature of the hot end of the thermoelectric semiconductor in the i-th column Equal to the heat flow inlet temperature of the i-th row of thermoelectric semiconductors and the heat flow inlet temperature of the i+1th row of thermoelectric semiconductors The average value of satisfies the equation: Among them, T in and T out are the temperatures of the heat flow inlet and heat flow outlet, respectively, and both are known conditions.

[0043] Step 4, calculate the relationship between the central angle difference Δθ of the thermoelectric semiconductor and the heat flow temperature, that is, satisfy the equation: Let i = 1, and solve for:

[0044] Step 5: Calculate the center angle of each thermoelectric semiconductor column, i.e., θ i =θ1+Δθ(i-1).

[0045] The known parameters of the ring-shaped thermoelectric device of this example are listed in Table 1.

[0046] Table 1: BiSbTeSe-based P-type semiconductor and N-type semiconductor thermoelectric material parameters

[0047]

[0048] Substituting the data in the table, after calculation, Δθ=0.066°, which satisfies the condition: (M-1)Δθ<α / 2. Therefore, according to the formula θ i =θ1+Δθ(i-1), it can be calculated that the central angles of the second to sixteenth columns of thermoelectric semiconductors are 2.066°, 2.132°, 2.198°, 2.264°, 2.330°, 2.396°, 2.462°, 2.528°, 2.594°, 2.660°, 2.726°, 2.792°, 2.858°, 2.924°, and 2.990°, respectively.

[0049] The working principle of the present invention is that heat flows through the variable angle annular thermoelectric device. As the heat flows, the fluid temperature will continue to decrease. At this time, the thermoelectric semiconductor (P-type thermoelectric semiconductor 5 and N-type thermoelectric semiconductor 6) at the lower heat flow temperature has a larger central angle. According to the formula By increasing the central angle, the effect of the decrease in current caused by the decrease in heat flow temperature is overcome, so that the current generated by the thermoelectric semiconductor remains unchanged, and the same current output is achieved for different columns of thermoelectric semiconductors, thus overcoming power loss and improving its output power.

[0050] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0051] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A variable angle annular thermoelectric device, characterized in that: The variable angle annular thermoelectric device comprises: An upper insulating substrate is used to isolate the current of the upper conductive sheet; The lower insulating substrate is used to isolate the current of the lower conductive sheet and sense the heat flow; The upper conductive sheet is used for conducting electricity; The lower end conductive sheet is used for conducting electricity; A P-type thermoelectric semiconductor, used to generate an electric current through a temperature difference between an end close to a lower insulating substrate and an end close to an upper insulating substrate; An N-type thermoelectric semiconductor, used to generate an electric current through a temperature difference between an end close to a lower insulating substrate and an end close to an upper insulating substrate; The upper insulating substrate, the lower insulating substrate, the upper conductive sheet, the lower conductive sheet, the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are all arc-shaped structures, the heat flow flows on the side of the lower insulating substrate away from the upper insulating substrate, the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are connected in series through the upper conductive sheet and the lower conductive sheet, and are sandwiched between the upper insulating substrate and the lower insulating substrate, and the geometric parameters of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are the same; the inner radii of the lower insulating substrate, the lower conductive sheet, the thermoelectric semiconductor, the upper conductive sheet and the upper insulating substrate are R1, R2, R3, R4 and R5 respectively, and the outer radius of the upper insulating substrate is R6; the number of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor is equal, both are n, and the number of the lower conductive sheet and the upper conductive sheet is equal, both are n / 2; The variable angle annular thermoelectric device is divided into M columns along the heat flow direction, the first column is close to the heat flow inlet, the Mth column is close to the heat flow outlet, and the central angle of the thermoelectric semiconductor in the i-th column is θ i , 1≤i≤M, the center angle between the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor in the first column is α, the center angles of the upper conductive sheet and the lower conductive sheet are equal, which is 2θ1+α, and the center angles of the upper insulating substrate and the lower insulating substrate are equal, which are 2n×θ1+(2n+1)α; The variable angle annular thermoelectric device also includes a calculation method, step 1, setting the range of the central angle difference Δθ of the thermoelectric semiconductors in adjacent columns; step 2, calculating the temperature relationship between the central angles of the thermoelectric semiconductors in adjacent columns; step 3, calculating the average temperature of the hot end of the thermoelectric semiconductor Step 4, calculating the relationship between the central angle difference Δθ of thermoelectric semiconductors in adjacent columns and the heat flow temperature; Step 5, calculating the central angle of each column of thermoelectric semiconductors.

2. The variable angle annular thermoelectric device according to claim 1, characterized in that: In step 1: the central angle of the thermoelectric semiconductor in the i+1th column is Δθ greater than the central angle of the thermoelectric semiconductor in the ith column, that is, θ i+1 =θ i +Δθ, where Δθ satisfies the relationship: (M-1)Δθ<α / 2, and θ1 is a known condition.

3. The variable angle annular thermoelectric device according to claim 1, characterized in that: In step 2: the output current of the thermoelectric semiconductor in the i-th column is equal to the output current of the thermoelectric semiconductor in the i+1th column, and the temperature relationship between the central angle of the thermoelectric semiconductor in the i-th column and the central angle of the thermoelectric semiconductor in the i+1th column is calculated, that is, the equation is satisfied: in is the average temperature of the hot end of the thermoelectric semiconductor in the i-th column, is the average temperature of the hot end of the thermoelectric semiconductor in the i+1th row, T c is the cold end temperature of the ring thermoelectric device.

4. The variable angle annular thermoelectric device according to any one of claims 1 to 3, characterized in that: In step 3: the average temperature of the hot end of the thermoelectric semiconductor in the i-th column Equal to the heat flow inlet temperature of the i-th row of thermoelectric semiconductors and the heat flow inlet temperature of the i+1th row of thermoelectric semiconductors The average value of satisfies the equation: Among them, T in and T out are the temperatures of the heat flow inlet and heat flow outlet, respectively, and both are known conditions.

5. The variable angle annular thermoelectric device according to claim 4, characterized in that: In step 4: calculate the relationship between Δθ and the heat flow temperature, that is, satisfy the equation: Let i = 1, and solve for:

6. The variable angle annular thermoelectric device according to claim 5, characterized in that: In step 5: calculate the central angle of each row of thermoelectric semiconductors, i.e. θ i =θ1+Δθ(i-1).

7. The variable angle annular thermoelectric device according to claim 1, characterized in that: The thickness of the lower insulating substrate is the same as that of the upper insulating substrate, that is, R2-R1=R6-R5, the thickness of the lower conductive sheet is the same as that of the upper conductive sheet, that is, R3-R2=R5-R4, and the thickness of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are both R4-R3.

Images