Honeycomb fin waste heat recovery device

Abstract

The invention relates to the field of thermoelectric power generation, in particular to a waste heat recovery device for honeycomb fins. Comprising honeycomb type fins, the n honeycomb type fins are arranged at intervals, n is larger than 1, and the adjacent honeycomb type fins are sequentially arranged in the radial direction to form the same included angle; the thermoelectric modules are connected with the honeycomb type fins in an attached mode; and the liquid cooling plate is connected with the thermoelectric module in an attached manner. Compared with an existing structure, the fin structure has the advantages that when the multiple fins are arranged, the included angle is formed between the adjacent fins, and the included angle is a fixed angle formed in the radial direction, so that the heat exchange area between waste gas and the fins is increased, and the heat exchange efficiency is improved; and the retention time of the tail gas in the device is further prolonged due to the design of complex flow channels formed among the fins, so that the heat can be transferred to a working medium more sufficiently and more uniformly and is further converted into electric energy.

Description

Technical Field

[0001] The invention relates to the field of thermoelectric power generation, and in particular to a waste heat recovery device of a honeycomb fin. Background Art

[0002] The underutilized heat energy contained in industrial exhaust gas has always been a problem studied by technicians. By converting the waste heat in the exhaust gas into electrical energy, it is not only possible to improve energy utilization efficiency, but also to bring substantial benefits to the environment and potential returns at the economic level.

[0003] Although traditional waste heat recovery devices have achieved the conversion of heat from exhaust gas to usable energy, the effect has not met people's expectations. These devices are often limited by design structure or material properties and cannot fully absorb and convert every bit of heat in the exhaust gas. As the gas passes through the waste heat recovery device, although most of the heat energy is absorbed, the waste heat discharged at the tail end is still considerable, which is not only a huge waste of energy, but also limits the improvement of the overall energy recovery efficiency.

[0004] Based on the above background issues, there is an urgent need for a structure that can significantly improve the thermal energy absorption efficiency.

[0005] Therefore, there is an urgent need for a structure that can improve energy absorption efficiency to solve the problems in the background technology. Summary of the invention

[0006] In response to the problems mentioned in the prior art, the present invention proposes a waste heat recovery device with honeycomb fins, which can increase the contact area between the exhaust gas and the heat exchanger, ensuring that the waste heat in the exhaust gas can be more fully utilized, thereby achieving the optimal output power of the thermoelectric semiconductor as a whole, and effectively improving the power transmission performance of the thermoelectric generator.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] The present invention provides a waste heat recovery device for a honeycomb fin, comprising:

[0009] Honeycomb fins, n honeycomb fins are arranged at intervals, n>1, wherein adjacent honeycomb fins are arranged in rotation in sequence at the same angle along the radial direction;

[0010] A plurality of rows of thermoelectric modules, wherein the thermoelectric modules are bonded and connected to the honeycomb fins;

[0011] A liquid cooling plate is bonded to the thermoelectric module.

[0012] As a further improvement of the present invention, the honeycomb fin is circular, and a plurality of hexagonal holes are provided on the surface of the honeycomb fin;

[0013] The radius of each honeycomb fin is the same;

[0014] The radius of the circumscribed circle of each hole is r i , the spacing between adjacent holes is t i , where r i+ t i The value of is a fixed value.

[0015] As a further improvement of the present invention, the distance between adjacent honeycomb fins remains unchanged along the heat flow direction.

[0016] As a further improvement of the present invention, the thickness of the honeycomb fins remains unchanged.

[0017] As a further improvement of the present invention, the radial angle between the first honeycomb fin and the nth honeycomb fin is 0°.

[0018] As a further improvement of the present invention, the thermoelectric module is arranged in a ring shape, and the thermoelectric module includes a ceramic plate, a conductive sheet, a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor;

[0019] The ceramic plate is in a hollow cylindrical shape, a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor are arranged between the two ceramic plates, and the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are connected to the ceramic plates through a conductive sheet.

[0020] As a further improvement of the present invention, each row of thermoelectric modules is arranged at equal intervals along the heat flow direction, and each row of thermoelectric modules has the same width.

[0021] As a further improvement of the present invention, the number of P-type thermoelectric semiconductors and N-type thermoelectric semiconductors in the same column is the same, which is m, wherein m=1, 2, 3;

[0022] The number of conductive sheets is m / 2;

[0023] The P-type thermoelectric semiconductors and the N-type thermoelectric semiconductors in the same row are alternately distributed.

[0024] As a further improvement of the present invention, the liquid cooling plate includes a shell and a liquid cooling pipe arranged in the shell.

[0025] As a further improvement of the present invention, the axial length of the honeycomb fin is equal to the axial length of the thermoelectric module.

[0026] Compared with the prior art, the present invention has achieved the following technical effects:

[0027] The present invention proposes a waste heat recovery device with honeycomb fins. The fin structure of the device is different from the existing structure in that, when the multiple fins are arranged, an angle is formed between adjacent fins, and the angle is a fixed angle formed along the radial direction. This structure not only increases the heat exchange area between the exhaust gas and the fins, but the complex flow channel design formed between the fins further prolongs the residence time of the exhaust gas in the device, so that the heat can be transferred to the working medium more fully and evenly, and then converted into electrical energy.

[0028] The present invention can effectively solve the problem of underutilized heat energy loss in industrial exhaust gas, thereby significantly improving energy recovery efficiency and output power, making reasonable use of heat energy, improving the heat exchange efficiency of the device, and further improving the overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the waste heat recovery device of the honeycomb fin of the present invention;

[0030] Figure 2 It is a front schematic diagram of the waste heat recovery device of the honeycomb fin of the present invention;

[0031] Figure 3 A schematic diagram of a honeycomb fin of a waste heat recovery device of a honeycomb fin of the present invention;

[0032] Figure 4 A schematic diagram showing a comparison of honeycomb fins of a waste heat recovery device of a honeycomb fin of the present invention;

[0033] Figure 5 A schematic diagram of the honeycomb fin structure of the waste heat recovery device of the honeycomb fin of the present invention;

[0034] Figure 6 A schematic diagram of the honeycomb fin spacing of the waste heat recovery device of the honeycomb fin of the present invention;

[0035] Figure 7 A schematic diagram of the structure of a thermoelectric module of a waste heat recovery device of a honeycomb fin of the present invention;

[0036] Figure 8 It is a schematic diagram of the arrangement of thermoelectric modules of the waste heat recovery device of the honeycomb fin of the present invention;

[0037] Fig. 9 Schematic diagram for comparing the results of the embodiments of the present invention.

[0038] Figure numerals: 1. thermoelectric semiconductor; 2. conductive sheet; 3. honeycomb fin; 4. ceramic plate; 5. housing; 6. liquid cooling pipe; 8. thermoelectric module. DETAILED DESCRIPTION

[0039] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0041] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0042] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0044] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0045] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0046] like Figure 1 As shown, the present invention is a waste heat recovery device of a honeycomb fin, comprising: a honeycomb fin 3, wherein n honeycomb fins 3 are arranged at intervals, n>1, wherein adjacent honeycomb fins 3 are arranged in rotation in sequence to form the same angle along the radial direction; a plurality of rows of thermoelectric modules 8, wherein the thermoelectric modules 8 are bonded and connected to the honeycomb fins 3; and a liquid cooling plate, wherein the liquid cooling plate is bonded and connected to the thermoelectric modules 8.

[0047] In the embodiment, the number of honeycomb fins 3 can be increased or decreased according to different usage scenarios or different requirements. When the exhaust gas passes through the honeycomb fins 3, multiple honeycomb fins 3 form an angle, which can increase the contact area between the exhaust gas and the heat exchanger, ensuring that the waste heat in the exhaust gas can be more fully utilized, thereby achieving the overall optimal output power of the thermoelectric semiconductor 1 and effectively improving the power transmission performance of the thermoelectric generator.

[0048] Implementation example Figure 3 and Figure 4 The figure shows a comparison diagram of the embodiment of the present invention and the existing fins. Figure 3 The adjacent honeycomb fins 3 form an angle of θ1, and each honeycomb fin 3 is arranged in sequence along the angle θ1 along the direction of exhaust gas passing. In this way, since a plurality of honeycomb fins 3 are provided with a plurality of holes on the surface, different holes are arranged in an interlaced manner to form a complex airflow channel for exhaust gas to pass through. Figure 4 When θ1 is 0°, the holes on the honeycomb fin 3 are all aligned, so the exhaust gas will directly pass through the holes and will not stay for a longer time.

[0049] The honeycomb fin 3 is circular, and a plurality of hexagonal holes are arranged on the surface of the honeycomb fin 3; the radius of each honeycomb fin 3 is the same; the radius of the circumscribed circle corresponding to each hole is r i , the spacing between adjacent holes is t i , where r i+ t i The value of is a constant. The spacing between adjacent honeycomb fins 3 remains unchanged along the heat flow direction. The thickness of the honeycomb fins 3 remains unchanged.

[0050] Implementation example Figure 2 , Figure 5 as well as Figure 6 The figure shows the parameters of the honeycomb fin 3 of the present invention, wherein the honeycomb fin 3 is a circular structure with a plurality of hexagonal holes on its surface. The number of holes can be increased or decreased according to different usage scenarios or requirements, so no restrictions are imposed here.

[0051] In the embodiment Figure 5 As shown, the spacing between the holes is t i , the radius of the circumscribed circle corresponding to each hole is r i , where r i+ t i The value is a fixed value, so the hole spacing and the size of each hole can be changed within the fixed value range. It can be modified according to application requirements, and the fixed value is determined according to the performance of the entire device.

[0052] In the embodiment, the size and specifications of each hole of the honeycomb fin 3 are the same, so when the exhaust gas passes through, the flow rate of the exhaust gas in each hole is evenly distributed. When the upstream and downstream pressure differences are the same, the outflow rate of each hole is also the same, which helps to reduce the unevenness of the exhaust gas in the flow process and improve the overall efficiency of the device; at the same time, the evenly distributed holes can reduce the eddy and turbulence phenomena generated by the exhaust gas when passing through, reducing energy loss and noise pollution.

[0053] In the embodiment, the size, spacing and thickness of the honeycomb fins 3 are all set to be the same, so that the resistance encountered by the exhaust gas when passing through the honeycomb fins 3 is basically the same, which helps to achieve uniformity of fluid flow; the spacing between adjacent honeycomb fins 3 remains unchanged, so that the heat exchange path of the exhaust gas when passing through the honeycomb fin 3 array is consistent, which helps to achieve stable heat exchange performance, and at the same time, the contact time and contact area between the exhaust gas and the honeycomb fins 3 are relatively uniform, thereby improving the heat transfer efficiency; the design of the entire honeycomb fin 3 is modular and standardized, so the number and spacing of the honeycomb fins 3 can be flexibly adjusted according to actual needs to adapt to waste heat recovery of different scales and types.

[0054] The radial angle between the first honeycomb fin 3 and the nth honeycomb fin 3 is 0°. In practice, the first honeycomb fin 3 and the nth honeycomb fin 3 overlap and do not form an angle, satisfying nθ1=2π.

[0055] like Figure 7 and Figure 8As shown, in the embodiment, the thermoelectric module 8 is arranged in an annular manner, and the thermoelectric module 8 includes a ceramic plate 4, a conductive sheet 2, a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor; the ceramic plate 4 is in a hollow cylindrical shape, the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are arranged between two ceramic plates 4, and the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are connected to the ceramic plate 4 through the conductive sheet 2. Each column of thermoelectric modules 8 is arranged equidistantly along the heat flow direction, and the width of each column of thermoelectric modules 8 is the same. The number of P-type thermoelectric semiconductors and N-type thermoelectric semiconductors in the same column is the same, both are m, where m = 1, 2, 3; the number of conductive sheets 2 is m / 2; the P-type thermoelectric semiconductors and N-type thermoelectric semiconductors in the same column are staggered.

[0056] In the embodiment, the thermoelectric semiconductor 1 includes adjacent P-type thermoelectric semiconductors and N-type thermoelectric semiconductors. Specifically, the geometric parameters of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are the same; Figure 7 As shown, the central angle corresponding to each column of P-type thermoelectric semiconductors and N-type thermoelectric semiconductors is θ2, and the central angle corresponding to the interval between adjacent P-type thermoelectric semiconductors and N-type thermoelectric semiconductors is θ3, so the central angle corresponding to the conductive sheet 2 is 2θ2+θ3.

[0057] In the embodiment, there are two conductive sheets 2, one is arranged at the top and the other is arranged at the bottom. The thickness of the two conductive sheets 2 is the same, and the thickness of the ceramic plate 4 is also the same.

[0058] The liquid cooling plate includes a shell 5 and a liquid cooling pipe 6 arranged in the shell 5. In the embodiment, the liquid cooling plate is composed of the shell 5 and the liquid cooling pipe 6 in the shell 5, the shell 5 is double-layered, the shell 5 facing the inside is connected to the ceramic plate 4, and the shell 5 facing the outside is in contact with the air; the liquid cooling pipe 6 is an S-shaped cylinder, and the S-shaped channel can extend the passage time of the cooling medium and further improve the cooling effect; the left and right ends of the same side of the shell 5 are respectively provided with a channel inlet and a channel outlet, wherein the channel inlet is connected to the medium inlet of the liquid cooling pipe 6, and the channel outlet is connected to the medium outlet of the liquid cooling pipe 6, to ensure that the cooling medium can pass smoothly, and the cooling medium in this embodiment is preferably cooling water.

[0059] The axial length of the honeycomb fin 3 is equal to the axial length of the thermoelectric module 8 .

[0060] The present invention proposes a waste heat recovery device with honeycomb fins. The fin structure of the device is different from the existing structure in that when the multiple fins are arranged, an angle is formed between adjacent fins, and the angle is a fixed angle formed along the radial direction. This structure not only increases the heat exchange area between the exhaust gas and the fins, but the complex flow channel design formed between the fins further prolongs the residence time of the exhaust gas in the device, so that the heat can be more fully and evenly transferred to the working medium, and then converted into electrical energy. The present invention can effectively solve the problem of underutilized heat energy loss in industrial exhaust gas, thereby significantly improving energy recovery efficiency and output power, making reasonable use of heat energy, improving the heat exchange efficiency of the device, and further improving the overall performance.

[0061] In order to verify the effect of the structure and the existing structure, this embodiment is verified by using COMSOL simulation. Figure 3 and Figure 4 As shown, in order to reduce the calculation time, 5 honeycomb fins are selected, each of which has 37 holes. The sizes and parameters of other structures such as thermoelectric modules and liquid cooling plates are the same. For example, there are 16 pairs * 16 rows of thermoelectric semiconductors on the annular thermoelectric module.

[0062] The total output power of the entire device is calculated as follows:

[0063]

[0064] Where: P i represents the output power of the i-row annular thermoelectric module, represents the square of the output voltage of the i-th row of annular thermoelectric modules, M represents the number of rows of thermoelectric modules, and RL is the load resistance, where the load resistance is 12.5Ω.

[0065] When the air flow passes through the heat exchanger, back pressure loss occurs:

[0066]

[0067] Where: G air is the mass flow rate of the exhaust gas, ρ(T) is the air density at this temperature, and ΔP is the pressure drop between the inlet and outlet.

[0068] Among them, G air =0.005, ρ(T)=0.7, and ΔP are obtained by COMSOL simulation.

[0069] Table 1 shows the various boundary conditions required for the simulation, including the inlet temperature and mass flow rate of the exhaust gas.

[0070] Table 1 Boundary conditions required for simulation

[0071]

[0072] The thermoelectric materials used in the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor used in this example are bismuth telluride-based thermoelectric materials. The parameters of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor and other materials are shown in Table 2.

[0073] Table 2 Material parameters of bismuth telluride-based thermoelectric devices

[0074]

[0075] The relevant size parameters of other components are shown in Table 3

[0076] Table 3 Specific parameters of components

[0077]

[0078] like Fig. 9 As shown in FIG. 1 , the angle between two adjacent honeycomb fins in the present invention is selected here respectively. The heat exchange device with θ1=0° (non-staggered) and θ1=90° is selected for performance comparison. It can be seen that the improvement effect is obvious. The output power of the latter is increased by 12.6% compared with the former. The comparison effect is as follows: Fig. 9 shown.

[0079] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0080] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0081] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0082] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A waste heat recovery device for honeycomb fins, characterized in that: include: Honeycomb fins, n honeycomb fins are arranged at intervals, n>1, wherein adjacent honeycomb fins are arranged in rotation in sequence at the same angle along the radial direction; A plurality of rows of thermoelectric modules, wherein the thermoelectric modules are bonded and connected to the honeycomb fins; A liquid cooling plate is bonded to the thermoelectric module.

2. The waste heat recovery device of a honeycomb fin according to claim 1, characterized in that: The honeycomb fin is circular, and a plurality of hexagonal holes are provided on the surface of the honeycomb fin; The radius of each honeycomb fin is the same; The radius of the circumscribed circle of each hole is r i , the spacing between adjacent holes is t i , where r i+ t i The value of is a fixed value.

3. The waste heat recovery device of a honeycomb fin according to claim 2, characterized in that: The spacing between adjacent honeycomb fins remains unchanged along the heat flow direction.

4. The waste heat recovery device of a honeycomb fin according to claim 3, characterized in that: The thickness of the honeycomb fins remains unchanged.

5. The waste heat recovery device of a honeycomb fin according to claim 1, characterized in that: The angle between the first honeycomb fin and the nth honeycomb fin along the radial direction is 0°.

6. The waste heat recovery device of a honeycomb fin according to claim 1, characterized in that: The thermoelectric module is arranged in a ring shape, and includes a ceramic plate, a conductive sheet, a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor; The ceramic plate is in a hollow cylindrical shape, a P-type thermoelectric semiconductor and an N-type thermoelectric semiconductor are arranged between the two ceramic plates, and the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor are connected to the ceramic plates through a conductive sheet.

7. The waste heat recovery device of a honeycomb fin according to claim 6, characterized in that: Each row of thermoelectric modules is arranged at equal intervals along the heat flow direction, and each row of thermoelectric modules has the same width.

8. The waste heat recovery device of a honeycomb fin according to claim 7, characterized in that: The number of P-type thermoelectric semiconductors and N-type thermoelectric semiconductors in the same column is the same, which is m, where m = 1, 2, 3; The number of conductive sheets is m / 2; The P-type thermoelectric semiconductors and the N-type thermoelectric semiconductors in the same row are alternately distributed.

9. The waste heat recovery device of a honeycomb fin according to claim 1, characterized in that: The liquid cooling plate comprises a shell and a liquid cooling pipeline arranged in the shell.

10. A waste heat recovery device for honeycomb fins according to any one of claim 1, characterized in that: The axial length of the honeycomb fin is equal to the axial length of the thermoelectric module.

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