CN109065697B - Annular thermoelectric power generation device - Google Patents

Abstract

The invention relates to an annular thermoelectric power generation device which is in a non-closed annular state and comprises P-type thermoelectric elements and n-type thermoelectric elements which are alternately distributed in an annular mode, inner annular electrodes used for connecting adjacent P-type thermoelectric elements and n-type thermoelectric elements to form thermoelectric pairs, and outer annular electrodes used for connecting the P-type thermoelectric elements and the n-type thermoelectric elements which are positioned adjacently in the adjacent thermoelectric pairs.

Description

A ring thermoelectric power generation device

technical field

The invention relates to a non-planar heat source thermoelectric power generation device, in particular to a ring-shaped thermoelectric power generation device, and belongs to the technical field of thermoelectric power generation.

Background technique

Thermoelectric power generation technology uses the Seebeck effect of semiconductor materials to directly convert thermal energy into electrical energy. It has the characteristics of small system size, compact structure, no moving parts, no maintenance, no noise, no emissions, high reliability and long life. It has obtained important applications in detection power supply and special military power supply, and has broad application prospects and potential economic and social benefits in solar photovoltaic-thermoelectric composite power generation, industrial waste heat, especially automobile exhaust waste heat recovery thermoelectric power generation, and may become today's An important part of the solution to the world energy crisis (T.M.Tritt, Thermoelectric materials-Holey and unholey semiconductors, Science 283:804, 1999).

Thermoelectric power generation devices are key components of thermoelectric power generation systems, and are usually composed of multiple p/n-type semiconductor thermoelectric elements. Due to the small Seebeck coefficient of thermoelectric materials, the output voltage of a single thermoelectric element is low. In order to obtain a high enough voltage for practical use, a p-type thermoelectric element and an n-type thermoelectric element are often connected to form a thermoelectric element using metal or alloy electrodes. Monocouple (or called π-shaped thermoelectric element), and then connect a plurality of thermoelectric monocouples according to the structure of electrical conductivity in series and thermal conductivity in parallel to form a thermoelectric device.

A common thermoelectric power generation device is a planar structure composed of multiple π-shaped thermoelectric elements, see Fig. 1(a). In this structure, p-type and n-type thermoelectric elements are integrated between parallel ceramic plates with electrical insulation and good thermal conductivity in the manner of electrical series connection and thermal conductivity in parallel. ceramic plate.

However, when the heat source is non-planar, such traditional flat-plate modular thermoelectric devices are no longer applicable, such as automobiles, aircraft exhaust pipes, etc. The arc-shaped surface is not only unfavorable for the installation of flat-plate modular devices, but also unfavorable. Heat is transferred to the thermoelectric device to establish a temperature difference, which greatly affects the thermoelectric conversion efficiency of the thermoelectric device. In response to this problem, patents US2012/0174567A1, CN201420052870, CN201410846352, CN201410846295, CN201410626515, CN201410626099, CN201410039382 and CN201420052870 disclose the integrated structure of generators (thermoelectric devices in Fig. The heat source can exchange heat with the thermoelectric element from the radial and axial directions, which significantly improves the heat exchange efficiency compared with the traditional generator integrated by the π-type device.

Although the concept of the existing annular thermoelectric power generation device satisfies the application requirements of the exhaust pipe well, there are still some problems in its practical application. Existing annular thermoelectric power generation devices are suitable for tubular heat sources with small diameters, but when the diameters of heat sources are large, large-sized block thermoelectric material preparation technology, component processing technology and device integration restrict their practical application. For those heat sources whose diameters are large enough to allow for improved design, flat-plate thermoelectric devices can be used along the circumferential design and processing plane of the heat source for heat recovery and power generation; however, for those heat sources with limited space that do not allow for improved design, such as the tail of a drone The waste heat of the nozzle, especially when the tail nozzle part is a conical structure (Fig. 2), the existing flat-plate thermoelectric devices and annular thermoelectric power generation devices cannot effectively recover the waste heat from the exhaust gas for thermoelectric power generation, and it is necessary to develop a new structure of thermoelectric power generation. power generation device.

SUMMARY OF THE INVENTION

In view of the above problems, the purpose of the present invention is to provide a ring-shaped thermoelectric power generation device, the annular thermoelectric power generation device is in a non-closed loop state, and includes p-type thermoelectric elements and n-type thermoelectric elements alternately distributed in a ring shape, for connecting adjacent p-type thermoelectric elements The element and the n-type thermoelectric element constitute the inner ring electrode of the thermoelectric pair, and the outer ring electrode for connecting the p-type thermoelectric element and the n-type thermoelectric element in adjacent positions in the adjacent thermoelectric pair.

The annular thermoelectric power generation device of the present invention can use a plurality of p-type and n-type thermoelectric elements to surround a non-planar heat source, and fit a small plane to a large plane, which is convenient for heat transfer and device placement, and can be adjusted according to the diameter of the heat source. The number of thermoelectric pairs in the ring device, or the cross-sectional size of its thermoelectric element can be changed, so as to meet the needs of practical applications, improve the power generation efficiency and output power density of the device, and effectively recover the waste heat of the special-shaped heat source and generate thermoelectric power.

Preferably, a welding layer is further included between the inner ring electrode and the p-type thermoelectric element and the n-type thermoelectric element, and/or a welding layer is also included between the outer ring electrode and the p-type thermoelectric element and the n-type thermoelectric element. , the material of the welding layer is at least one of tin, gold, silver, copper, nickel, titanium and alloys thereof.

Preferably, a barrier layer is further included between the solder layer and the p-type thermoelectric element and the n-type thermoelectric element, and the material of the barrier layer is at least one of Ni, Fe, Ti, Mo and Nb.

Preferably, the material of the thermoelectric pair is bismuth telluride-based thermoelectric material, lead telluride-based thermoelectric material, transition metal oxide thermoelectric material, semi-Hassler thermoelectric material, skutterudite-based thermoelectric material, germanium-silicon-based thermoelectric material. At least one of a material and a copper-based compound thermoelectric material.

Preferably, the size of the p-type thermoelectric element and/or the n-type thermoelectric element is length×width×height=(3～5)mm×(3～5)mm×(2～5)mm.

Preferably, the inner ring electrode and the outer ring electrode have a folded angle along the direction of the center line between adjacent p-type thermoelectric elements and n-type thermoelectric elements.

Preferably, the folding angle of the inner ring electrode is 150-175 degrees, and the folding angle of the outer ring electrode is 150-175 degrees. The folded corners are for ease of preparation.

Preferably, the materials of the inner ring electrode and the outer ring electrode are selected from at least one of copper, iron, nickel, chromium, cobalt, titanium, molybdenum, tungsten, niobium and alloys thereof.

Preferably, the structure of the p-type thermoelectric element and the n-type thermoelectric element is a cube, a rectangular parallelepiped, or a rhomboid, and the inclination angle of the rhomboid is determined by the taper of the heat source.

Preferably, the p-type thermoelectric element and the n-type thermoelectric element have the same size, and the ratio of the inner diameter of the annular thermoelectric power generation device to the cross-sectional side length of the p-type thermoelectric element and the n-type thermoelectric element is >10.

Description of drawings

Fig. 1 is a flat-plate thermoelectric device (a) and a ring-type thermoelectric device (b) in the prior art;

Figure 2 shows the special shape of the heat source;

3 is a schematic diagram of the three-dimensional structure of a ring-shaped thermoelectric power generation device suitable for a conical heat source in Example 1 of the present invention;

4 is a schematic diagram of a three-dimensional structure of a rhombohedral thermoelectric element of an annular thermoelectric power generation device suitable for a conical heat source in Example 1 of the present invention;

5 is a schematic diagram of the three-dimensional structure of the annular thermoelectric power generation device in Example 2 of the present invention;

6 is a schematic diagram of a thermoelectric monocouple of the annular thermoelectric power generation device in Example 2 of the present invention;

FIG. 7 is a schematic flow chart of the preparation of the annular thermoelectric power generation device according to the present invention.

Detailed ways

The present invention is further described below through the following embodiments, and it should be understood that the following embodiments are only used to illustrate the present invention, but not to limit the present invention.

In order to overcome the defects of the existing thermoelectric devices, the present invention provides a ring-shaped thermoelectric power generation device with a novel structure to effectively recover the waste heat of a heat source with a special structure for thermoelectric power generation.

In an embodiment of the present invention, the annular thermoelectric power generation device is in a non-closed loop state, and its structure includes: a plurality of p-type thermoelectric elements, n-type thermoelectric elements, and n-type thermoelectric elements for connecting the Electrodes of p-type thermoelectric element and n-type thermoelectric element. Among them, the electrodes are divided into inner ring electrodes and outer ring electrodes. Wherein, the inner ring electrode and the outer ring electrode have a bent angle along the direction along the center line between the p-type thermoelectric element and the n-type thermoelectric element (ie, the middle of the length direction of the inner ring electrode and the outer ring electrode). The p-type thermoelectric element and the n-type thermoelectric element alternately surround the heat source, and the p-type thermoelectric element and the n-type thermoelectric element are alternately connected by the inner ring electrode and the outer ring electrode in turn to form an electrically conductive series and thermally conductive parallel structure.

In an optional embodiment, the annular thermoelectric power generation device further includes a barrier layer and a solder layer. In an optional embodiment, a welding layer is further included between the inner ring electrode and the p-type thermoelectric element and the n-type thermoelectric element, and the material of the welding layer can be tin, gold, silver, copper, nickel, titanium and alloys thereof At least one of them may have a thickness of 50-150 μm. In an optional embodiment, a welding layer is further included between the outer ring electrode and the p-type thermoelectric element and the n-type thermoelectric element, and the material of the welding layer can be tin, gold, silver, copper, nickel, titanium and alloys thereof At least one of them may have a thickness of 50-150 μm. In an optional embodiment, a barrier layer is further included between the solder layer and the p-type thermoelectric element and the n-type thermoelectric element, and the material of the barrier layer can be at least one of Ni, Fe, Ti, Mo and Nb, Thickness can be 20 ~ 150mm.

In an optional embodiment, the thermoelectric materials of the p-type thermoelectric element and the n-type thermoelectric element constituting the annular thermoelectric power generation device include: bismuth telluride (Bi ₂ Te ₃ ) based thermoelectric material, lead telluride (PbTe) based thermoelectric materials, transition metal oxide thermoelectric materials, half-Heusler thermoelectric materials, skutterudite based thermoelectric materials, silicon germanium (SiGe) based thermoelectric materials, copper-based compound thermoelectric materials (such as copper -Sulfur, copper-selenium, tetrahedrite, etc.) and their doped composite thermoelectric materials and multi-stage thermoelectric materials composed of them can be selected according to the temperature of the heat source.

In an optional embodiment, the electrodes of the annular thermoelectric power generation device are divided into an inner ring electrode and an outer ring electrode. The size and number of the elements determine the size of the folded angle, so that the electrodes and the thermoelectric elements can be in close contact with the heat source. Generally, the folding angle of the inner ring electrode is 150-175 degrees, and the folding angle of the outer ring electrode is 150-175 degrees. The materials of the electrodes include metals such as copper, iron, nickel, chromium, cobalt, titanium, molybdenum, tungsten, niobium and their alloys and composite materials.

In an alternative embodiment, the structure of the p-type thermoelectric element and the n-type thermoelectric element may be a cube, a rectangular parallelepiped, or a rhombus. When the p-type thermoelectric element and the n-type thermoelectric element are rhomboid (see FIG. 4 ), the inclination angle of the rhombic p-type thermoelectric element and the rhombic n-type thermoelectric element is determined by the taper of the heat source, and the p-type thermoelectric element is The element and n-type thermoelectric element are coupled in pairs, as shown in Figure 6.

In an optional embodiment, the cross-sectional dimensions of the p-type thermoelectric elements and the n-type thermoelectric elements are the same, and the heights of the p-type thermoelectric elements and the n-type thermoelectric elements are the same. The p-type thermoelectric elements and the n-type thermoelectric elements are alternately surrounded in a ring and are connected in series to each other, thereby forming a single-ring and multiple-pair series thermoelectric device.

In an optional embodiment, the ratio of the inner diameter of the annular thermoelectric power generation device to the length of the p-type thermoelectric element and the n-type thermoelectric element is greater than 10. The cross section of the p-type thermoelectric element and the n-type thermoelectric element refers to the surface connected to the inner ring electrode and the outer ring electrode, and the shape is generally square. Generally speaking, the inner ring of the annular thermoelectric power generation device is the high temperature end, and the outer ring is the low temperature end.

As an example of the structure of a ring-shaped thermoelectric power generation device, as shown in FIG. 3 , the ring-shaped thermoelectric power generation device includes: a plurality of pairs of column-type p-type thermoelectric elements and n-type thermoelectric elements 2, and each pair of the p-type thermoelectric elements is connected outside the ring and the outer ring conducting electrode 1 of the n-type thermoelectric element, and connecting adjacent pairs of the p-type thermoelectric element and the inner ring conducting electrode 3 of the n-type thermoelectric element in the form of staggered with the outer ring conducting electrode on the inside of the ring.

In the present invention, the annular thermoelectric power generation device is in a non-closed loop state, and includes p-type thermoelectric elements and n-type thermoelectric elements alternately distributed in an annular shape, an inner ring electrode for connecting adjacent p-type thermoelectric elements and n-type thermoelectric elements to form a thermoelectric pair, And the outer ring electrodes used to connect the P-type thermoelectric elements and the n-type thermoelectric elements in adjacent positions in the adjacent thermoelectric pairs can effectively recover the waste heat of the special-shaped heat source and generate thermoelectric power. The manufacturing method of the annular thermoelectric power generation device is exemplarily described below, as shown in FIG. 7 . A mold for preparing an annular thermoelectric power generation device includes a convex base, an annular tray cooperating with the convex base, a clamping ring and a pressing ring.

Flux and solder tabs were prepared on both end faces of the p-type thermoelectric element and the n-type thermoelectric element. In an optional embodiment, the size of the p/n type thermoelectric element is length×width×height=(3˜5mm)×(3˜5mm)×(2˜5mm). The material of the soldering piece includes: tin, gold, silver, copper, nickel, titanium and alloys thereof; the thickness of the soldering piece is 50-150m. In an optional embodiment, the thermoelectric materials composing the p-type and n-type thermoelectric elements include: bismuth telluride (Bi ₂ Te ₃ ) based thermoelectric materials, lead telluride (PbTe) based thermoelectric materials, transition metal oxides Thermoelectric materials, Half-Heusler thermoelectric materials, Skutterudite-based thermoelectric materials, SiGe-based thermoelectric materials, copper-based compound thermoelectric materials (such as copper-sulfur, copper-selenium, copper ore, etc.) and its doped composite thermoelectric materials and multi-stage thermoelectric materials composed of them. In addition, a barrier layer can be added on the two end faces of the p-type thermoelectric element and the n-type thermoelectric element before the flux is applied, and the material of the barrier layer can be at least one of Ni, Fe, Ti, Mo and Nb, The thickness may be 20-150 μm.

Place the ring tray on the convex base. The shape and size of the boss of the convex base are consistent with the shape and size of the heat source. The materials selected for the convex base include cast iron, ordinary steel, alloy steel, stainless steel, aluminum and its alloys, and graphite with good strength and thermal conductivity. Wherein, the annular tray cooperates with the convex base, and the materials selected for the annular tray include cast iron, ordinary steel, alloy steel, stainless steel, aluminum and its alloys, and graphite with good strength and thermal conductivity.

Let the inner ring electrode be close to the boss of the convex base and evenly distribute it on the ring tray, and the end faces of the p-type thermoelectric element and the n-type thermoelectric element are alternately close to the above-mentioned p-type/n-type/p-type The inner ring electrodes are evenly distributed on the ring tray.

The outer ring electrodes are abutted against the other end faces of the p-type thermoelectric elements and the n-type thermoelectric elements and are evenly distributed on the annular tray at a distance from the inner ring electrodes. According to the present invention, the materials used for the inner ring electrode and the outer ring electrode include: electrode materials include metals such as copper, iron, nickel, chromium, cobalt, titanium, molybdenum, tungsten, niobium, and their alloys and composite materials; The ring electrode and the outer ring electrode present a certain fold angle according to the diameter of the annular thermoelectric device, and the fold angle ranges from 150° to 175°.

Push the clamping ring from the edge of the boss base to the outer ring electrode, so that the clamping ring presses the outer ring ring electrode, the p-type thermoelectric element, the n-type thermoelectric element, and the inner ring electrode to complete the ring thermoelectric power generation device. assembled. In an optional embodiment, the upper part of the outer ring of the tightening ring is chamfered, and the angle is 25-75°; preferably, the clamping ring is divided into 3-8 petals. In an optional embodiment, the pressing ring is placed on the clamping ring, and the assembly of the annular thermoelectric power generation device is completed by the gravity of the pressing ring.

The solder tab is heated to obtain the annular thermoelectric power generation device. The heating method may be resistance heating or induction heating.

As an example of the preparation method of a ring-shaped thermoelectric power generation device, it includes: (1) Coating a layer of flux on the upper and lower end surfaces of the p-type thermoelectric element and the n-type thermoelectric element, and using the adhesiveness of the flux to paste solder sheets with similar areas, Complete the preparation of flux and solder tabs on the end faces of the p-type thermoelectric element and the n-type thermoelectric element; (2) place the ring tray on the convex base; (3) make the inner ring electrode abut against the convex base of the convex base The end faces of the p-type thermoelectric elements and the n-type thermoelectric elements are alternately abutted against the inner ring electrodes and evenly distributed on the annular tray according to the p-type thermoelectric elements and the n-type thermoelectric elements and are evenly distributed on the annular tray. The ring electrode is close to the other end face of the p-type thermoelectric element and the n-type thermoelectric element and is staggered from the inner ring electrode and evenly distributed on the annular tray; (4) The split clamping ring is removed from the boss base The edge is pushed to the outer ring electrode, and the pressing ring is placed on the clamping ring, and the clamping ring is pressed against the inner ring electrode, p-type thermoelectric element and n-type thermoelectric element by the gravity of the pressing ring and the outer ring electrode to complete the assembly of the annular thermoelectric device; (5) the heating pad connects the inner ring electrode, the p-type thermoelectric element, the n-type thermoelectric element and the outer ring electrode to complete the welding integration of the annular thermoelectric device; (6) After cooling to room temperature, the pressing ring is removed, the clamping ring is removed, and the annular tray is lifted to obtain the annular thermoelectric power generation device.

The following further examples are given to illustrate the present invention in detail. It should also be understood that the following examples are only used to further illustrate the present invention, and should not be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art according to the above content of the present invention belong to the present invention. scope of protection. The specific process parameters and the like in the following examples are only an example of a suitable range, that is, those skilled in the art can make selections within the suitable range through the description herein, and are not intended to be limited to the specific numerical values exemplified below.

Example 1

This embodiment is an annular thermoelectric power generation device designed according to the tapered pipe portion of the UAV exhaust pipe (Fig. 2) with a temperature of ~500°C;

The thermoelectric material of the annular thermoelectric power generation device in this embodiment is filled with skutterudite material, the n-type is Yb _0.3 Co ₄ Sb ₁₂ , the p-type is Ce _0.9 Fe ₄ Sb ₁₂ , and the current conducting electrodes (inner ring electrode and outer ring electrode) are selected The material is nickel sheet, and the electrode and the thermoelectric material are connected by solder (the material is silver-copper alloy solder sheet), and the thickness of the solder layer formed by the solder is 100 μm;

The structure of the annular thermoelectric power generation device in this embodiment is shown in FIG. 3 , the inner annular surface of the annular thermoelectric power generation device in this embodiment is the high temperature end, and the outer annular surface is the low temperature end;

The annular thermoelectric power generation device in this embodiment is composed of 21 p/n thermoelectric pairs in total, and its inner diameter is 52 mm. Among them, the p-type thermoelectric element and the n-type thermoelectric element are rhombus (Fig. 4), and the inclination angle is 114.65°. The size is 3×3mm and the thickness is 2mm;

The length of the inner ring electrode of the annular thermoelectric power generation device in this embodiment is 6.5 mm, and the folding angle is 170 degrees; the length of the outer ring electrode is 7 mm, and the folding angle is 170 degrees;

When the annular thermoelectric power generation device in this embodiment is integrated, the p-type and n-type thermoelectric elements are alternately arranged in the radial direction, and are connected along the inner ring electrode and the outer ring electrode by solder.

Example 2

This embodiment is an annular thermoelectric power generation device designed according to the straight pipe portion of the UAV exhaust pipe heat source (Fig. 2) with a temperature of ~500°C and a diameter of Φ56.6;

The thermoelectric materials and electrodes selected for the annular thermoelectric power generation device in this embodiment are the same as those in Embodiment 1;

The structure of the annular thermoelectric power generation device in this embodiment is shown in FIG. 5 , the inner annular surface of the annular thermoelectric power generation device in this embodiment is the high temperature end, and the outer annular surface is the low temperature end;

The straight tube is a special case of the tapered tube, which is equivalent to the inclination angle equal to 90°. According to the design calculation, the annular thermoelectric power generation device in this embodiment is composed of 22 p-type thermoelectric elements and n-type thermoelectric element pairs in total, and the inner diameter length is 56.6 mm. The cross-sectional dimensions of the p-type thermoelectric element and the n-type thermoelectric element are 3×3mm, the thickness is 2.5mm;

The bending angle of the inner ring electrode and the outer ring electrode of the annular thermoelectric power generation device of this embodiment is 173.75° (Fig. 6), and the lengths are respectively 6.5mm and 7mm;

When the annular thermoelectric power generation device is integrated in this embodiment, the p-type thermoelectric elements and the n-type thermoelectric elements are alternately arranged in the radial direction, and are connected with the inner ring electrode and the outer ring electrode by solder.

Example 3

This embodiment is aimed at a tubular heat source with an outer wall temperature of ~500°C and an outer diameter of Φ56.6mm (Fig. 2):

(1) Preparation of thermoelectric elements

Using filled skutterudite thermoelectric material, the n-type is Yb _0.3 Co ₄ Sb ₁₂ , and the p-type is Ce _0.9 Fe ₄ Sb ₁₂ . First, the filled skutterudite powder was synthesized and prepared, then sintered into a bulk material, cut into 2.5mm thick slices, and a barrier layer (the material was Ti, with a thickness of ~150mm) and a flux layer were prepared on the upper and lower sides of the material, and then Cut into 3×3×2.5mm particles, and finally apply flux and paste silver-copper alloy solder sheets (thickness 100μm) for use;

(2) Welding mold

The outer diameter of the heat source is the inner diameter of the annular device. Correspondingly, the diameter of the boss part of the convex base is also Φ56.6mm and the height is 10mm, while the diameter of the lower base can be designed and processed as Φ72mm and the height is 10mm; the diameter of the outer ring of the annular tray is Φ74mm, The height is 4mm; the diameter of the inner ring of the clamping ring is Φ63.2mm, which is divided into 6 petals and numbered. The above parts are processed with high-strength graphite. The pressure ring is matched with the clamping ring, and the material used is 304 stainless steel;

(3) Ring device assembly

The inner and outer ring electrodes are all made of 0.3mm nickel sheets. The inner ring electrode size is 3×6.5×0.3mm, and the outer ring electrode size is 3×7×0.3mm. The folding angle of the ring electrode is 172.36°; the ring tray is placed on the convex base; the inner ring electrode is close to the boss of the convex base and evenly placed on the ring tray, and the p/n type filled skutterudite thermoelectric element is pressed p /n-type alternate end faces are close to the inner ring electrode and are evenly placed on the annular tray, and the outer ring electrode is close to the other end face of the p/n-type filled skutterudite thermoelectric element and is evenly placed on the annular tray staggered from the inner ring electrode; The split clamping ring is pushed from the edge of the boss base to the outer ring electrode, and the pressure ring is placed on the clamping ring, and the clamping ring is pressed against the inner ring electrode, the p/n type thermoelectric element and the inner ring electrode by the gravity of the pressure ring. The outer ring electrode completes the assembly of the ring thermoelectric device;

(4) Ring device welding integration

Place the assembled annular filled skutterudite thermoelectric device together with the mold in a hot-pressing furnace, evacuate, fill with argon, heat up to ~670°C, pressurize to ~12KN, hold for ~40 minutes, and connect the hot welding piece to the The inner ring electrode, p/n type thermoelectric element and outer ring electrode complete the welding and integration of the ring thermoelectric device; then power off and cool down to below 50 °C, remove the pressure, take out the device and mold, remove the pressure ring, and remove the clamping ring , hold up the annular tray, and obtain the annular thermoelectric power generation device filled with skutterudite.

Example 4

This embodiment is aimed at a tubular heat source with an outer wall temperature of ~250°C and an outer diameter of Φ56.6mm (Figure 2):

(1) Preparation of thermoelectric elements

A bismuth telluride-based thermoelectric material is used, and the n-type is Bi ₂ Sb _2.7 Te _0.3 , and the p-type is Bi _0.5 Sb _1.5 Te ₃ . The fused crystal rod was cut into 2.5mm thick pieces, and Ni layers were prepared on the upper and lower sides as a barrier layer and a flux layer (thickness of ~20μm), and then cut into 3 × 3 × 2.5 mm particles, and finally coated with Apply flux and paste lead-tin alloy solder sheet (thickness is 100μm), spare;

(2) Welding mold

The dimensions of the convex base, the annular tray, and the tightening ring are the same as those of Embodiment 1, and the material is aluminum alloy. The size and material of the pressure ring are the same as those in Example 1;

(3) Ring device assembly

The inner ring and outer ring electrodes are made of 0.3mm copper sheets, and their dimensions and folding angles are the same as those in Example 1; the assembly steps of the ring device are the same as those in Example 1;

(4) Ring device welding integration

In the air of the heating platform, the temperature is raised to ~300°C, and the temperature is maintained for ~30 seconds, and the inner ring electrode, the p/n type thermoelectric element and the outer ring electrode are thermally welded and melted to complete the welding integration of the ring thermoelectric device; then Power off and cool down to room temperature, remove the pressing ring, remove the clamping ring, and hold up the ring tray to obtain a bismuth telluride-based ring thermoelectric power generation device.

Claims (8)

1. The annular thermoelectric power generation device is characterized by being in a non-closed annular state and consisting of P-type thermoelectric elements and n-type thermoelectric elements which are alternately distributed in an annular mode, inner ring electrodes used for connecting the adjacent P-type thermoelectric elements and n-type thermoelectric elements to form thermoelectric pairs, and outer ring electrodes used for connecting the P-type thermoelectric elements and the n-type thermoelectric elements which are positioned at the adjacent positions in the adjacent thermoelectric pairs; the inner ring electrode and the outer ring electrode form an angle in the direction of a midline between the adjacent p-type thermoelectric element and the adjacent n-type thermoelectric element, the angle of the inner ring electrode is 150-175 degrees, and the angle of the outer ring electrode is 150-175 degrees;

the preparation method of the annular thermoelectric power generation device comprises the following steps:

(1) preparing soldering flux and soldering lugs on two end faces of the p-type thermoelectric element and the n-type thermoelectric element;

(2) placing an annular tray on a convex base, enabling an inner ring electrode to abut against a boss of the convex base and be uniformly distributed on the annular tray, and alternately abutting end faces of a P-type thermoelectric element and an n-type thermoelectric element against the inner ring electrode according to a P type, an n type and a P type and uniformly distributing the end faces on the annular tray;

(3) an outer ring electrode is abutted against the other end faces of the p-type thermoelectric element and the n-type thermoelectric element and is uniformly distributed on the annular tray in a staggered manner with the inner ring electrode;

(4) pushing the clamping ring from the edge of the boss base to the outer ring electrode, so that the clamping ring presses the outer ring electrode, the p-type thermoelectric element, the n-type thermoelectric element and the inner ring electrode to complete the assembly of the annular thermoelectric power generation device;

(5) and heating the soldering lug to obtain the annular thermoelectric power generation device.

2. The ring thermoelectric power generation device according to claim 1, further comprising a solder layer between the inner ring electrode and the p-type and n-type thermoelectric elements, and/or further comprising a solder layer between the outer ring electrode and the p-type and n-type thermoelectric elements; the welding layer is made of at least one of tin, gold, silver, copper, nickel, titanium and alloy thereof, and the thickness of the welding layer is 50-150 mu m.

3. The ring-shaped thermoelectric power generation device according to claim 2, further comprising a barrier layer between the welding layer and the p-type thermoelectric element and the n-type thermoelectric element, wherein the barrier layer is made of at least one of Ni, Fe, Ti, Mo, and Nb and alloys thereof and has a thickness of 20 μm to 150 μm.

4. The ring thermoelectric power generation device according to claim 1, wherein the material of the thermoelectric pair is at least one of a bismuth telluride-based thermoelectric material, a lead telluride-based thermoelectric material, a transition metal oxide thermoelectric material, a half heusler thermoelectric material, a skutterudite-based thermoelectric material, a silicon germanium-based thermoelectric material, and a copper-based compound thermoelectric material.

5. The ring-shaped thermoelectric power generation device according to claim 1, wherein the p-type thermoelectric element and/or the n-type thermoelectric element have a size of length x width x height = (3-5) mm x (2-5) mm.

6. The annular thermoelectric power generation device of claim 1, wherein the material of the inner and outer ring electrodes is selected from at least one of copper, iron, nickel, chromium, cobalt, titanium, molybdenum, tungsten, elemental niobium, and alloys thereof.

7. The ring-type thermoelectric power generation device according to claim 1, wherein the p-type thermoelectric element and the n-type thermoelectric element have a square, rectangular, or rhomboid structure, and an inclination angle of the rhomboid is determined by a taper of the heat source.

8. The ring-shaped thermoelectric power generation device according to any one of claims 1 to 7, wherein the p-type thermoelectric elements and the n-type thermoelectric elements are the same in size, and the ratio of the inner diameter of the ring-shaped thermoelectric power generation device to the side length of the cross section of the p-type thermoelectric elements and the n-type thermoelectric elements is more than 10.

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