Heat exchanger

Abstract

The utility model discloses a heat exchanger which comprises a heat exchange plate body and a plurality of fins, the heat exchange plate body is of a hollow structure, the fins are sequentially arranged in the heat exchange plate body at intervals in the height direction of the heat exchange plate body, and a cold side cavity or a hot side cavity is formed between every two adjacent fins. The cold side cavity and the hot side cavity are adjacently arranged in the height direction of the heat exchange plate body, the heat exchange plate body is provided with a cold side inlet, a cold side outlet, a hot side inlet and a hot side outlet, a cold side channel is formed in the cold side cavity, and a hot side channel is formed in the hot side cavity; and the fluid in the cold side chamber exchanges heat with the fluid in the hot side chamber. Heat exchange is carried out between hot flow gas and cold flow gas through the fins and does not need to be carried out through a partition plate, and therefore the heat exchange efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of fuel cells, in particular to a heat exchanger. Background Art

[0002] In the fields of fuel cells and solid oxide electrolytic cells (SOECs), it is necessary to preheat the reactants introduced into the fuel cells or solid oxide electrolytic cells (SOECs) to reduce the temperature difference between the reactants and the optimal operating temperature and improve the working efficiency. At the same time, the exhaust gas temperature discharged during the operation of the fuel cell or solid oxide electrolytic cell (SOEC) is extremely high and contains a large amount of heat energy. Therefore, in a fuel cell system or a solid oxide electrolytic cell (SOEC) system, a heat exchanger is usually adopted to recover the heat energy of the flue gas and preheat the reactants.

[0003] A plate heat exchanger is composed of a group of corrugated metal plates. There are four corner holes on the plates for two heat-transfer fluids to pass through. The cold-side fluid passes through the inlet corner hole inside the corrugated metal plate into the flow channel, and the hot-side fluid passes through the opposite inlet corner hole inside the corrugated metal plate into the flow channel. The two fluids exchange heat through the corrugated metal plates. It has the advantages of small dedicated space and convenient installation and disassembly. However, in the prior art, a plate-fin heat exchanger uses a partition to separate the fins. The fins on the partition pass through one fluid (for example: cold flow), and the fins under the partition pass through another fluid (for example: hot flow). In this way, the two fluids exchange heat through the partition. During the heat exchange process, part of the heat is dissipated in the partition, reducing the heat exchange efficiency. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is that in the prior art, a plate-fin heat exchanger uses a partition to separate the fins, and the two fluids exchange heat through the partition. During the heat exchange process, part of the heat is dissipated in the partition, reducing the heat exchange efficiency.

[0005] To solve the above technical problem, the utility model provides a heat exchanger, including a heat exchange plate body and a plurality of fins. The heat exchange plate body is of a hollow structure. The plurality of fins are sequentially arranged at intervals along the height direction of the heat exchange plate body inside the heat exchange plate body. A cold-side chamber or a hot-side chamber is formed between two adjacent fins. The cold-side chamber and the hot-side chamber are arranged adjacent to each other along the height direction of the heat exchange plate body. The heat exchange plate body is provided with a cold-side inlet, a cold-side outlet, a hot-side inlet, and a hot-side outlet. A cold-side channel is provided in the cold-side chamber, and a hot-side channel is provided in the hot-side chamber, so that the fluid in the cold-side chamber exchanges heat with the fluid in the hot-side chamber.

[0006] Further, connecting baffles are respectively arranged on two sides of the fin along its length direction, and adjacent fins are connected by the connecting baffles. Flat areas are arranged on two sides of the fin connected to the connecting baffle.

[0007] Further, one end of the cold-side chamber or the hot-side chamber along the width direction of the fin is open to form the cold-side inlet or the hot-side inlet, and the other end of the cold-side chamber or the hot-side chamber is closed. A notch is formed at one end of the connecting baffle away from the cold-side inlet or the hot-side inlet, and the notch constitutes the cold-side outlet or the hot-side outlet.

[0008] A plurality of channels are formed on one side surface of the fin facing the cold-side chamber or the hot-side chamber to constitute the cold-side channels of the cold-side chamber or the hot-side channels of the hot-side chamber.

[0009] Further, the fin has two ends arranged along the width direction of the fin, and sealing parts are arranged at both ends.

[0010] Further, the sealing part includes a first sealing structure which is flat.

[0011] Further, the sealing part further includes an upper bar and a lower bar. The upper bar is attached to the upper surface of the first sealing structure along the height direction of the fin, and the lower bar is attached to the lower surface of the first sealing structure along the height direction of the fin.

[0012] Further, the fin further includes a ridge connecting the two ends. The ridge has a plurality of the channels, and the cross-section of the ridge viewed along the width direction is in the shape of several rectangles, several arcs or several trapezoids.

[0013] Further, a support plate is further included between adjacent fins, and the support plate is arranged on the ridge.

[0014] Further, the ratio range of the straight-line distance from the end of the support plate to the cold-side inlet or the hot-side inlet to the length of the heat exchange plate body is 1:10 - 1:20.

[0015] Further, the height of the fin is greater than 4 mm and less than 10 mm.

[0016] Compared with the prior art, the beneficial effects of an exchanger according to an embodiment of the present utility model are as follows:

[0017] In the embodiment of the present utility model, the fin itself separates the cold-side chamber and the hot-side chamber. Different-temperature airflows are respectively introduced into the two surfaces of the fin facing the cold-side chamber and the hot-side chamber. The hot-flow gas and the cold-flow gas exchange heat through the fin itself without passing through a partition, thereby improving the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of a heat exchanger provided by an embodiment of the present utility model;

[0019] Figure 2 is a schematic structural diagram of the heat exchanger provided by the embodiment of the present utility model without including a connecting baffle;

[0020] Figure 3 is a schematic structural diagram of the fin provided by the embodiment of the present utility model;

[0021] In the figure, 1, heat exchange plate body; 11, cold-side inlet; 12, cold-side outlet; 13, hot-side inlet; 14, hot-side outlet; 15, connecting baffle; 2, fin; 21, channel; 22, flat area; 23, sealing part; 231, first sealing structure; 232, bar; 24, ridge; 3, cold-side chamber; 31, cold-side channel; 4, hot-side chamber; 41, hot-side channel; 5, support plate. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following combines the drawings and embodiments to further describe in detail the specific implementation manners of the present utility model. The following embodiments are used to illustrate the present utility model but are not used to limit the scope of the present utility model.

[0023] As Figure 1 and Figure 2 shown, the present utility model provides a heat exchanger, including a heat exchange plate body 1 and a plurality of fins 2. The heat exchange plate body 1 is a hollow structure. The plurality of fins 2 are sequentially arranged at intervals along the height direction of the heat exchange plate body 1 inside the heat exchange plate body 1. A cold-side chamber 3 or a hot-side chamber 4 is formed between two adjacent fins 2. The cold-side chamber 3 and the hot-side chamber 4 are adjacently arranged along the height direction of the heat exchange plate body 1. The heat exchange plate body 1 is provided with a cold-side inlet 11, a cold-side outlet 12, a hot-side inlet 13, and a hot-side outlet 14. A cold-side channel 31 is provided in the cold-side chamber 3, and a hot-side channel 41 is provided in the hot-side chamber 4, so that the fluid in the cold-side chamber 3 exchanges heat with the fluid in the hot-side chamber 4.

[0024] Based on the above structure, in this embodiment, the fin 2 itself separates the cold-side chamber 3 and the hot-side chamber 4. Different-temperature airflows are respectively introduced into the two surfaces of the fin 2 facing the cold-side chamber 3 and the hot-side chamber 4. The hot-flow gas and the cold-flow gas exchange heat through the fin 2 itself without passing through a partition, thereby improving the heat exchange efficiency.

[0025] It should be noted that in the actual application process, multiple flat fins 2 can also be stacked. A cold-side chamber 3 or a hot-side chamber 4 is formed between two adjacent fins 2. The cold-side chamber 3 and the hot-side chamber 4 are arranged adjacent to each other, and the adjacent cold-side chamber 3 and hot-side chamber 4 share the same fin 2. The more fins 2 are stacked, the greater the heat exchange amount. While achieving the heat exchange efficiency, the compactness of the device can be improved, and the occupied area of the device can be reduced. In addition, compared with the annular heat exchanger, the flat-plate heat exchanger has a high compactness, can reduce the volume of the hot box components of the SOFC system, and further reduce the volume of the entire system, meeting the requirements of fuel cell power generation.

[0026] Refer to together Figure 3 On one side surface of the fin 2 facing the cold-side chamber 3 or the hot-side chamber 4, a plurality of channels 21 are formed to constitute the cold-side channel 31 of the cold-side chamber 3 or the hot-side channel 41 of the hot-side chamber 4, which are used to guide the fluid to flow along a predetermined path, increase the contact area between the fluid and the fin 2, and thus improve the heat exchange efficiency.

[0027] Furthermore, one end of the cold-side chamber 3 or the hot-side chamber 4 along the width direction of the fin 2 is open to constitute the cold-side inlet 11 or the hot-side inlet 13 to allow the fluid to enter. The other end of the cold-side chamber 3 or the hot-side chamber 4 is closed. A notch is formed at one end of the connecting baffle 15 away from the cold-side inlet 11 or the hot-side inlet 13, and the notch constitutes the cold-side outlet 12 or the hot-side outlet 14 for the discharge of the fluid. In this structure, the hot and cold flow modes can be selected according to needs. If the cold-side inlet 11 and the hot-side inlet 13 are located on the same side, then the co-current mode can be achieved; if the cold-side channel 31 and the hot-side channel 41 are perpendicular to each other, then the staggered mode can be achieved; if the cold-side inlet 11 and the hot-side inlet 13 are arranged oppositely, and the cold-side channel 31 and the hot-side channel 41 are arranged parallel to the length direction of the fin 2, then the counter-current mode can be achieved.

[0028] Preferably, the cold-side inlet 11 and the hot-side inlet 13 are arranged oppositely, and the cold-side outlet 12 / hot-side outlet 14 are arranged on both sides of the fin 2. It can be understood that in adjacent two layers, one layer is provided with the cold-side inlet, and the other layer is provided with the hot-side inlet on the side opposite to the cold-side inlet, and the cold-side channel 31 and the hot-side channel 41 are arranged parallel to the length direction of the fin 2, so as to achieve the counter-current mode, and the heat exchange efficiency is relatively high through the counter-current setting.

[0029] Connecting baffles 15 are respectively arranged on two side edges of the fin 2 arranged along its length direction, and two adjacent fins 2 are connected by the connecting baffle 15 to define the cold-side chamber 3 or the hot-side chamber 4. This baffle not only helps to maintain the structural integrity of the chamber, but also ensures that the cold-side fluid and the hot-side fluid flow in their respective chambers and avoid mixing.

[0030] Furthermore, flat areas 22 are provided on both sides where the fin 2 is connected to the connecting baffle 15. In this embodiment, the flat area 22 refers to the two side portions where the fin 2 is connected to the connecting baffle 15, and the shape is designed to be a plane instead of the original corrugated or channel 21 structure, and is arranged in the direction parallel to the channel 21 of the fin 2, so as to facilitate the connection and stacking of two adjacent fins 2. Among them, the flat area 22 can be set by bending the fin 2 or welding a connecting piece at the fin 2, which provides a larger contact area and enhances the stability and reliability of the connection.

[0031] Furthermore, the fin 2 has two ends arranged along the width direction of the fin 2, and sealing portions 23 are provided at both ends.

[0032] It should be noted that the sealing portion 23 in this embodiment is used to separately seal the channel 21 ports of the fin 2 corresponding to the cold side inlet 11 / cold side outlet 12 and the channel 21 ports of the fin 2 corresponding to the hot side inlet 13 / hot side outlet 14, ensuring that the cold side fluid and the hot side fluid flow in their respective channels and avoiding mutual mixing, so as to maintain effective heat exchange.

[0033] In some embodiments, the sealing portion 23 has various forms:

[0034] The sealing portion 23 includes a first sealing structure 231, and the first sealing structure 231 is flat. The first sealing structure 231 is formed by rolling the end of the fin 2 flat to perform sealing.

[0035] In addition, to further enhance the sealing effect, the sealing portion 23 further includes an upper bar 232 and a lower bar (not shown in the figure). The upper bar 232 is hermetically welded to the first sealing structure 231 along the height direction of the fin 2, and the lower bar is hermetically welded to the lower surface of the first sealing structure along the height direction of the fin 2. The upper bar 232 is located on the flattened cold and hot sides, and the bar 232 is hermetically welded to the flattened end to achieve the sealing purpose.

[0036] In some embodiments, the sealing portion 23 includes a sealing baffle. The sealing baffle has a plurality of notches arranged at intervals in sequence. The notches are arranged in one-to-one correspondence with the channels 21, and the sealing baffle is welded to the end. In this embodiment, the end of the fin 2 does not need to be flattened.

[0037] Furthermore, the fin 2 further includes a ridge portion 24 connecting the two ends. The ridge portion 24 has a plurality of channels, and the cross-section of the ridge portion 24 viewed along the width direction is in the shape of a plurality of rectangles or a plurality of arcs or a plurality of trapezoids. It can be understood that the above shapes can make the ridge portion 24 of the fin 2 maintain a stable and flat state, which is convenient for the fin 2 to be stacked with the fin 2.

[0038] Further, it also includes a support plate 5 located between two adjacent fins 2, and the support plate 5 is arranged on the ridge portion 24. The support plate 5 in this embodiment plays a supporting role for the fins 2, facilitating the stacking of the fins 2. The more fins 2 are stacked, the larger the heat exchange area and the higher the heat exchange efficiency.

[0039] It should be noted that the surface of the support plate 5 is welded to the ridge portion 24 of the fin 2 to achieve a tight connection. Among them, the welding can be absolutely sealed, that is, all the ridge portions 24 of the fins 2 in contact with the surface of the support plate 5 are welded; it can also be relatively sealed, that is, the welding is carried out at the places where the four peripheral edges of the support plate 5 are in contact with the ridge portion 24 of the fin 2.

[0040] Further, the ratio range of the straight-line distance from the end of the support plate 5 to the cold-side inlet 11 or the hot-side inlet 13 to the length of the heat exchange plate body 1 is 1:10 - 1:20. It can be understood that if the support plate 5 is too close to the air flow inlet (that is, the cold-side inlet 11 or the hot-side inlet 13), the air flow will enter through the gaps of the support plate 5, and a part of it will not flow through the channel 21 of the fin 2. If the support plate 5 is too far from the air flow inlet, the air flow will not flow through the channel 21 either, and the heat exchange efficiency is relatively low. Therefore, by setting the straight-line distance from the end of the support plate 5 to the cold / hot-side inlet 13 to be greater than 1:10 mm and less than 1:20 mm, the heat exchange efficiency can be further improved while avoiding excessive pressure loss.

[0041] Further, the height of the fin 2 is greater than 4 mm and less than 10 mm. If the height of the fin 2 is lower than the range, the heat exchange efficiency decreases and the pressure loss increases; if the height of the fin 2 is higher than the range, the heat exchange efficiency is lower and the pressure loss is smaller. Therefore, when the height of the fin 2 is within this range, the heat exchange efficiency is relatively high.

[0042] To further illustrate the heat exchange effect under this parameter, the following examples are given:

[0043] Among them, the ratio range of the straight-line distance from the end of the support plate 5 to the cold-side inlet 11 or the hot-side inlet 13 to the length of the heat exchange plate body 1 is L; the height of the fin 2 is H;

[0044] Comparative example 1 is used to reflect the heat exchange efficiency comparison between the partition heat exchange and the fin 2 heat exchange; comparative examples 2 - 3 and example 1 are used to reflect the heat exchange efficiency comparison when the ratio is not within the range; comparative examples 4 - 5 and example 1 reflect the heat exchange efficiency comparison when the height of the fin 2 is not within the range.

[0045] Number Partition heat transfer / fin heat transfer L H / mm Heat transfer efficiency Pressure loss (Pa) Example 1 Fin heat transfer 1:15 6 92％ 220 Comparative Example 1 Partition heat transfer 1:15 6 65％ 350 Comparative Example 2 Fin heat transfer 1:5 6 94％ 330 Comparative Example 3 Fin heat transfer 1:30 6 88％ 170 Comparative Example 4 Fin heat transfer 1:15 2 76％ 560 Comparative Example 5 Fin heat transfer 1:15 15 90％ 120

[0046] According to the above test data, it can be seen that the smaller the ratio L, the higher the heat exchange efficiency and the greater the pressure loss. When the height of the fin 2 is within the range, the heat exchange efficiency is optimal. If the height of the fin 2 is lower than the range, the heat exchange efficiency decreases and the pressure loss increases; if the height of the fin 2 is higher than the range, the heat exchange efficiency is lower and the pressure loss is smaller.

[0047] In addition, it should be noted that the ratio in the test data includes both the hot-side chamber 4 and the cold-side chamber 3. In the prior art, if partition heat exchange is adopted, generally the ratio designed for the hot-side chamber is 1:1, the partition covers the entire fin 2, and the ratio designed for the cold-side chamber 3 is 1:15, with an inlet reserved for shunting use, and the heat exchange efficiency is about 84%. In addition, in this embodiment, since fin 2 is used for heat exchange, a 1:1 design will not be adopted for the hot side. If a 1:1 design is adopted, the air flow will pass through the gaps in the partition, which is not convenient for heat exchange.

[0048] In summary, the embodiment of the present utility model provides a heat exchanger, which separates the cold-side chamber 3 and the hot-side chamber 4 through the fin 2 itself, and different-temperature air flows are introduced into the two surfaces of the fin 2 facing the cold-side chamber 3 and the hot-side chamber 4 respectively. The hot air flow and the cold air flow exchange heat through the fin 2 itself without passing through a partition for heat exchange, thereby improving the heat exchange efficiency. In addition, the ends of the fin 2 corresponding to the cold-side inlet and the hot-side inlet are sealed to prevent the mixing of hot and cold gases.

[0049] The above is only the preferred embodiment of the present utility model. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present utility model, several improvements and replacements can be made, and these improvements and replacements should also be regarded as the protection scope of the present utility model.

Claims

1. A heat exchanger, characterized in that, It includes a heat exchange plate body and a plurality of fins. The heat exchange plate body is a hollow structure. The plurality of fins are sequentially arranged at intervals along the height direction of the heat exchange plate body within the heat exchange plate body. A cold side chamber or a hot side chamber is formed between two adjacent fins. The cold side chamber and the hot side chamber are arranged adjacent to each other along the height direction of the heat exchange plate body. The heat exchange plate body is provided with a cold side inlet, a cold side outlet, a hot side inlet, and a hot side outlet. A cold side channel is provided in the cold side chamber, and a hot side channel is provided in the hot side chamber, so that the fluid in the cold side chamber exchanges heat with the fluid in the hot side chamber.

2. The heat exchanger according to claim 1, wherein Two side edges of the fin arranged along its length direction are respectively provided with connecting baffles, and two adjacent fins are connected by the connecting baffles. Flat areas are provided on both sides of the fin connected to the connecting baffles.

3. The heat exchanger according to claim 2, characterized in that, One end of the cold side chamber or the hot side chamber along the width direction of the fin is open to form the cold side inlet or the hot side inlet. The other end of the cold side chamber or the hot side chamber is closed. A notch is formed at one end of the connecting baffle away from the cold side inlet or the hot side inlet, and the notch forms the cold side outlet or the hot side outlet. A plurality of channels are formed on one side surface of the fin facing the cold side chamber or the hot side chamber to form the cold side channel of the cold side chamber or the hot side channel of the hot side chamber.

4. The heat exchanger according to claim 3, characterized in that, The fin has two ends arranged along the width direction of the fin, and sealing parts are provided at both ends.

5. The heat exchanger according to claim 4, wherein, The sealing part includes a first sealing structure, and the first sealing structure is flat.

6. The heat exchanger according to claim 5, characterized in that, The sealing part further includes an upper bar and a lower bar. The upper bar fits with the upper surface of the first sealing structure along the height direction of the fin, and the lower bar fits with the lower surface of the first sealing structure along the height direction of the fin.

7. The heat exchanger according to claim 4, characterized in that, The fin further includes a ridge connecting the two ends. The ridge has a plurality of the channels, and the cross-section of the ridge viewed along the width direction of the fin is in the shape of a plurality of rectangles, or a plurality of circular arcs, or a plurality of trapezoids.

8. The heat exchanger according to claim 7, characterized in that It further includes a support plate located between two adjacent fins, and the support plate is arranged on the ridge.

9. The heat exchanger according to claim 8, wherein, The ratio range of the straight-line distance from the end of the support plate to the cold side inlet or the hot side inlet to the length of the heat exchange plate body is 1:10 - 1:

20.

10. The heat exchanger according to claim 1, wherein, The height of the fin is greater than 4 mm and less than 10 mm.

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