A series-parallel heat exchange structure and thermovoltaic power generation device

Abstract

The present invention discloses a series-parallel heat exchange structure and a thermovoltaic power generation device, including more than two parallel heat exchange channels, the heat exchange channels including more than two heat exchange units, in each of the heat exchange channels, the heat exchange units are connected in series or in series-parallel, the heat exchange units include a number of parallel hot-end heat sinks used as hot liquid circulation channels, and a number of parallel cold-end heat sinks used as cold liquid circulation channels; the hot-end heat sinks and the cold-end heat sinks are arranged alternately. The present invention solves the integration problem of the heat exchange units, and the series-parallel connection structure is simple and compact, and multiple heat exchange units can be easily interconnected to form a higher-power thermovoltaic power generation system; the heat exchange structure of the present invention causes little flow resistance loss to the heat exchange medium, and the temperature difference between the inlet and outlet of the cold and hot end medium of each heat exchange unit is small, which is conducive to improving the overall thermoelectric conversion efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of thermovoltaic power generation, and in particular to a series-parallel heat exchange structure and a thermovoltaic power generation device. Background Art

[0002] Thermoelectric materials are functional materials that directly convert heat and electricity based on the thermoelectric effect (Seebeck effect, Peltier effect and Thomson effect). Based on the Seebeck effect, thermoelectric materials can be made into thermovoltaic power generation systems to directly convert heat into electricity, which can then be used for industrial waste heat recovery and power generation from heat sources such as radioisotopes and geothermal energy. Thermovoltaic power generation systems made of thermoelectric materials have the advantages of simple structure, small size, no moving parts, long life, safety, and environmental protection. At present, there is no large-scale integrated heat exchange device to meet the actual application needs.

[0003] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, an object of the present invention is to provide a series-parallel heat exchange structure and a thermovoltaic power generation device, aiming to solve the problem that there is currently no large-scale integrated solution for heat exchange devices.

[0005] The technical solution of the present invention is as follows:

[0006] A series-parallel heat exchange structure includes two or more parallel heat exchange channels, each of which includes two or more heat exchange units. In each of the heat exchange channels, the heat exchange units are connected in series or in series-parallel. The heat exchange units include a plurality of parallel hot-end heat sinks used as hot liquid circulation channels, and a plurality of parallel cold-end heat sinks used as cold liquid circulation channels; the hot-end heat sinks and the cold-end heat sinks are arranged alternately.

[0007] In the series-parallel heat exchange structure, the flow directions of the hot liquid and the cold liquid in the heat exchange unit are set to be opposite.

[0008] The series-parallel heat exchange structure, wherein in each of the heat exchange channels, three heat exchange units are provided and are connected in series.

[0009] In the series-parallel heat exchange structure, in each of the heat exchange channels, three heat exchange units are provided, two of which are connected in parallel and then in series with another one.

[0010] The series-parallel heat exchange structure, wherein the heat exchange unit also includes 4 heat sink headers, 2 of which are used to connect the hot end heat sink; the other 2 heat sink headers are used to connect the cold end heat sink, and the heat sink headers are also provided with holes for connecting liquid conduits.

[0011] The series-parallel heat exchange structure, wherein the two heat sink headers for connecting the hot end heat sink are arranged at the two corners of the first diagonal of the heat exchange unit; the two heat sink headers for connecting the cold end heat sink are arranged at the two corners of the second diagonal of the heat exchange unit.

[0012] In the series-parallel heat exchange structure, a plurality of ribs for diverting liquid are arranged inside the hot-end heat sink and the cold-end heat sink, and diverter grooves are formed between adjacent ribs.

[0013] In the series-parallel heat exchange structure, the ribs are arranged perpendicular to the direction of liquid inflow / outflow.

[0014] In the series-parallel heat exchange structure, the distance between the end of the rib and the edge of the hot-end heat sink / the cold-end heat sink gradually increases or decreases, so that when the liquid flows in, it is diverted into each diversion groove through the gradually contracting channel, and when the liquid flows out of the diversion groove, it converges to the gradually expanding channel and flows out.

[0015] A thermovoltaic power generation device comprises the series-parallel heat exchange structure as described above, and a thermoelectric module integrated in the series-parallel heat exchange structure, wherein the thermoelectric module generates electricity according to the temperature difference between the hot-end heat sink and the cold-end heat sink.

[0016] Beneficial effects: The present invention provides a series-parallel heat exchange structure as described above, which solves the integration problem of the heat exchange units by connecting all the heat exchange units in series and parallel respectively, and the series-parallel connection structure is simple and compact, and can easily realize the interconnection of multiple heat exchange units to form a higher-power thermovoltaic power generation system; the heat exchange structure of the present invention causes little flow resistance loss to the heat exchange medium, and the temperature difference between the inlet and outlet of the working medium at the cold and hot ends of each heat exchange unit is small, which is beneficial to improving the overall thermoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram showing an embodiment of a series-parallel heat exchange structure in which the heat exchange units in the heat exchange channel of the present invention adopt a simple series connection.

[0018] Figure 2 It is a schematic diagram of a series-parallel heat exchange structure in which the heat exchange units in the heat exchange channel of the present invention are connected in series and parallel.

[0019] Figure 3 It is a structural diagram of the heat exchange unit of the present invention.

[0020] Figure 4 It is a diagram of the internal structure of a preferred embodiment of the cold and hot end heat sinks of the present invention.

[0021] Figure 5This is a diagram of an embodiment of the non-vertical connection between the liquid header and the connecting pipe in the present invention.

[0022] Figure 6 The figure is a schematic diagram of the connection setting between the hot liquid inlet header and the first connecting pipe. DETAILED DESCRIPTION

[0023] The present invention provides a series-parallel heat exchange structure and a thermovoltaic power generation device. To make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] It should be noted that the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0025] A preferred embodiment of the series-parallel heat exchange structure provided by the present invention comprises two or more parallel heat exchange channels, wherein the heat exchange channels comprise two or more heat exchange units 1, and in each channel, the heat exchange units are connected in series or in series-parallel. Figure 1 Three heat exchange channels are provided, and three heat exchange units 1 are provided in each heat exchange channel, that is, three heat exchange units 1 are connected in series to form a heat exchange channel, and then connected in parallel to form a series-parallel heat exchange structure. Another series-parallel method of the present invention is as follows Figure 2 As shown, three heat exchange units 1 are provided, two of which are first connected in parallel and then in series with the third one. The three heat exchange units 1 are connected in series and parallel to form a heat exchange channel, which is then connected in parallel with other heat exchange channels. The specific number of series and parallel connections is set according to actual needs. The heat exchange unit 1 is as shown in FIG. Figure 3 As shown, it includes a plurality of hot-end heat sinks 11 connected in parallel, and a plurality of cold-end heat sinks 12 connected in parallel; the hot-end heat sinks 11 and the cold-end heat sinks 12 are arranged alternately.

[0026] Specifically, four liquid headers may be arranged in parallel: a hot liquid inlet header 2, a hot liquid outlet header 3, a cold liquid inlet header 4, and a cold liquid outlet header 5. The hot liquid flows through the hot liquid inlet header 2, the hot end heat sink 11, and the hot liquid outlet header 3 in sequence; the cold liquid flows through the cold liquid inlet header 4, the cold end heat sink 12, and the cold liquid outlet header 5 in sequence. Heat exchange occurs when the hot and cold liquids flow through the cold end heat sink 12 and the hot end heat sink 11, respectively. In order to ensure sufficient heat exchange time, the four headers may be made into a structure with one end open and the other end closed.

[0027] Figure 3A structure of an embodiment of a compact heat exchange unit 1 is provided, and a heat sink header 13 can be used to connect the hot end heat sink 11 and the cold end heat sink 12 in parallel. Specifically, four heat sink headers 13 are provided, of which two heat sink headers 13 are used to connect the hot end heat sink 11; the other two heat sink headers 13 are used to connect the cold end heat sink 12, and the heat sink headers 13 are also provided with holes for connecting liquid conduits. In order to facilitate integrated assembly and avoid mutual interference at the connection points, the two heat sink headers 13 used to connect the hot end heat sink 11 are arranged at the two corners of the first diagonal of the heat exchange unit 1; the two heat sink headers 13 used to connect the cold end heat sink 12 are arranged at the two corners of the second diagonal of the heat exchange unit 1. The heat sink header 13 can be integrated with the cold and hot end heat sinks by welding. The inlet area of ​​each cold and hot end heat sink, as well as the length of the inlet extending into the heat sink header 13 can be different. By adjusting the size of the inlet area and the length of the inlet, the flow rate flowing into each heat sink in the heat sink header 13 can be adjusted to achieve more accurate heat flow distribution. This technical solution is not only compact in structure, but also solves the parallel and integration problems of the hot end heat sink 11 and the cold end heat sink 12, and can regulate the heat flow. It avoids mutual interference caused by the installation positions of the cold and hot end heat sinks, and simplifies the connection and installation between the four headers and the heat exchange unit.

[0028] Furthermore, ribs L may be provided inside the heat sink (including the hot end heat sink 11 and the cold end heat sink 12), such as Figure 4 As shown, the adjacent ribs L form a diversion groove, which can divert the liquid. Preferably, the ribs are arranged perpendicular to the direction of liquid inflow / outflow, so that the inlet of cold and hot liquids is set on the same side to achieve countercurrent heat exchange, ensure sufficient heat exchange, and facilitate assembly and debugging. For specific flow direction settings, please refer to Figure 1 and Figure 3 Furthermore, the liquid inflow channel and outflow channel of the cold and hot end heat sinks can be designed as a gradually shrinking or expanding triangle. Specifically, the distance between the end of the rib and the edge of the hot end heat sink / the cold end heat sink gradually increases or decreases, so that when the liquid flows in, it is diverted into each diversion groove through the gradually shrinking channel, and when the liquid flows out of the diversion groove, it converges to the gradually expanding channel to flow out, so that the heat flow distribution can be more uniform.

[0029] In the preferred embodiment, the ends of the four headers are closed, and the flow stagnation will cause the static pressure to increase, resulting in more flow being distributed to the power generation unit near the position, thereby causing uneven flow distribution. Therefore, the present invention can connect the hot end heat sink 11 of each heat exchange unit 1 with the hot liquid inlet header 2 through first connecting pipes (6A, 6B, 6C, ...) of different lengths, and the arrangement of the first connecting pipes is as follows: along the flow direction of the liquid in the hot liquid inlet header, the length of the first connecting pipe increases successively, such as Figure 5 , Figure 6 As shown, along the flow direction of the liquid, by successively increasing the length of the connecting pipes and increasing a certain flow resistance, the flow rate of the heat exchange unit near the end of the hot liquid inlet header 2 can be reduced, that is, by adjusting the length of each first connecting pipe, the flow distribution from the hot liquid inlet header 2 to each heat exchange unit 1 can be adjusted.

[0030] Further preferably, the first connecting pipe is non-vertically connected to the hot liquid inlet header 2, so that when the hot liquid is diverted from the hot liquid inlet header to the first connecting pipe, the turning angle (θ) is an obtuse angle, such as Figure 5 As shown, the liquid flow can be smoother and the flow resistance can be reduced. Similarly, the cold end heat sink 12 and the cold liquid inlet manifold 5 can also be connected through second connecting pipes of different lengths. The specific connection method can be set according to the above method, which will not be repeated in the present invention.

[0031] The present invention also provides a thermovoltaic power generation device, comprising the series-parallel heat exchange structure as described above, and a thermoelectric module 7 integrated in the series-parallel heat exchange structure, such as Figure 3 As shown, the thermoelectric module 7 generates electricity according to the temperature difference between the hot end heat sink and the cold end heat sink. Specifically, a thermoelectric material can be arranged between the hot end heat sink and the cold end heat sink, for example, a PeTe material with a large coefficient of performance ZT (coefficient of merit) value is selected, and the thermoelectric material generates electricity according to the temperature difference. The thermovoltaic power generation device of the present invention has the characteristics of small liquid resistance, uniform internal flow distribution and heat exchange, and can maximize the thermoelectric conversion efficiency.

[0032] In summary, the present invention provides a series-parallel heat exchange structure and a thermovoltaic power generation device. The heat exchange structure not only solves the integration problem of the heat exchange unit, but also has a simple and compact series-parallel connection structure, which can easily realize the interconnection of multiple heat exchange units to form a higher-power thermovoltaic power generation system; the heat exchange structure of the present invention causes little flow resistance loss to the heat exchange medium, and the temperature difference between the inlet and outlet of the cold and hot end medium of each heat exchange unit is small, which is conducive to improving the overall thermoelectric conversion efficiency. The present invention further improves the specific structure of the heat exchange unit, connects the cold and hot end heat sinks in parallel through a heat sink manifold, cleverly sets the structure of the cold and hot end heat sinks, so that the cold and hot end medium can fully contact and exchange heat, and optimizes the flow distribution of the cold and hot end medium by adjusting the length and connection angle of the connecting pipe. Based on the above-mentioned series-parallel heat exchange structure, the present invention also provides a corresponding thermovoltaic power generation device, which has the characteristics of small liquid resistance, internal flow distribution and uniform heat exchange, and can maximize the thermoelectric conversion efficiency.

[0033] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A series-parallel heat exchange structure, characterized in that: The heat exchange channel comprises two or more parallel heat exchange channels, wherein the heat exchange channels comprise two or more heat exchange units, wherein in each heat exchange channel, the heat exchange units are connected in series or in series-parallel, and the heat exchange units comprise a plurality of parallel hot-end heat sinks used as hot liquid circulation channels, and a plurality of parallel cold-end heat sinks used as cold liquid circulation channels; the hot-end heat sinks and the cold-end heat sinks are arranged alternately; The hot liquid and the cold liquid flow directions in the heat exchange unit are arranged to be opposite; The heat exchange unit further comprises four heat sink headers, two of which are used to connect the hot end heat sink; the other two heat sink headers are used to connect the cold end heat sink, and the heat sink headers are also provided with holes for connecting liquid conduits; The heat sink header is integrated with the hot end heat sink and the cold end heat sink by welding; A plurality of ribs for diverting liquid are arranged inside the hot end heat sink and the cold end heat sink, and diverting grooves are formed between adjacent ribs; When the liquid flows into the heat sink, the distance between the end of the rib and the edge of the heat sink gradually decreases, so that the liquid flows into each diversion groove through the tapered channel; When the liquid flows out of the heat sink, the distance between the end of the rib and the edge of the heat sink gradually increases, so that the liquid flows out of the diversion groove and converges to the gradually expanding channel to flow out; Two heat sink headers for connecting the hot end heat sink are arranged at two corners of the first diagonal line of the heat exchange unit; two heat sink headers for connecting the cold end heat sink are arranged at two corners of the second diagonal line of the heat exchange unit; The ribs are arranged perpendicular to the direction in which the liquid flows in and out.

2. The series-parallel heat exchange structure according to claim 1, characterized in that: In each of the heat exchange channels, three heat exchange units are provided and are connected in series.

3. The series-parallel heat exchange structure according to claim 1, characterized in that: In each of the heat exchange channels, three heat exchange units are provided, two of which are connected in parallel and then connected in series with another one.

4. A thermovoltaic power generation device, characterized in that: It comprises the series-parallel heat exchange structure as described in any one of claims 1-3, and a thermoelectric module integrated in the series-parallel heat exchange structure, wherein the thermoelectric module generates electricity according to the temperature difference between the hot-end heat sink and the cold-end heat sink.

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