Heat exchange device and heat exchange method for fluid waste heat recovery

Abstract

The invention discloses a heat exchange device and a heat exchange method for fluid waste heat recovery, the heat exchange device comprises a support frame, the support frame is connected with a plurality of heat exchange units, and the heat exchange units are connected in series through a diversion channel to form a heat exchange main body; the two ends or the same side of the heat exchange body are provided with a heat release fluid inlet and a heat release fluid outlet in the horizontal direction and a heat absorption fluid inlet and a heat absorption fluid outlet in the vertical direction. The heat exchange unit comprises a plurality of heat conduction plates which are connected to form a horizontal fluid channel and a vertical fluid channel. The heat exchange method comprises the steps that a heat release fluid medium enters the horizontal fluid channels between the heat conducting plates of the heat exchange body from the heat release fluid inlet, meanwhile, a heat absorption fluid medium enters the vertical fluid channels between the heat conducting plates of the heat exchange body from the heat absorption fluid inlet, and heat is transferred through the heat conducting plates. The plate type heat exchanger can effectively solve the problems that a traditional plate type heat exchanger is large in wind resistance, low in pressure, limited in gasket temperature resistance, prone to aging and the like, and industrial application and popularization are easy.

Description

Technical Field

[0001] This invention belongs to the field of waste heat recovery and utilization technology, specifically relating to a heat exchange device and heat exchange method for fluid waste heat recovery. Background Art

[0002] In industrial production processes, waste gas often contains a large amount of heat energy. Direct emission not only wastes energy but also causes thermal pollution to the environment. While traditional shell-and-tube heat exchangers can achieve gas-to-gas heat exchange, they suffer from problems such as large size, low efficiency, and susceptibility to clogging. Plate heat exchangers, due to their compact structure and high heat exchange performance, have gradually become a research hotspot in the field of gas-to-gas heat exchange. However, existing plate heat exchangers generally employ a gasket-isolated structure, which suffers from high air resistance, low pressure resistance, limited gasket temperature resistance, and susceptibility to aging, thus restricting their application range. Summary of the Invention

[0003] The purpose of this invention is to provide a heat exchange device and method for recovering waste heat from fluids, which effectively solves the problems commonly found in traditional plate heat exchangers, such as high wind resistance, low pressure, limited gasket temperature resistance and easy aging, and is easy to promote and apply in industry.

[0004] To achieve the above objectives, the present invention provides a heat exchange device for fluid waste heat recovery, including a support frame, on which a plurality of heat exchange units are connected, and the heat exchange units are connected in series through a flow guide channel to form a heat exchange body.

[0005] The heat exchanger body has horizontally oriented heat-releasing fluid inlet and heat-releasing fluid outlet at both ends or on the same side, and vertically oriented heat-absorbing fluid inlet and heat-absorbing fluid outlet.

[0006] The heat exchange unit includes several heat-conducting plates, which are connected to form horizontal and vertical fluid channels that are spaced apart and perpendicular to each other. The horizontal fluid channels are connected to the heat-releasing fluid inlet and outlet, and the vertical fluid channels are connected to the heat-absorbing fluid inlet and outlet.

[0007] As a further aspect of the present invention: the heat-conducting plate is a rectangular or square structure, and is welded with opposite sides to form a horizontal fluid channel and a vertical fluid channel that are spaced apart from each other and perpendicular to each other, allowing two types of heat exchange gases to flow through.

[0008] As a further aspect of the present invention: notches are provided on the inner angle bisectors of the four corners of the heat-conducting plate, opposite sides of the heat-conducting plate are bent in the same direction, adjacent sides are bent in the opposite direction, and the bending width and bending angle are the same.

[0009] As a further aspect of the present invention: the bending width is greater than or equal to 1 / 2 of the distance between adjacent heat-conducting plates, and the bending angle is less than or equal to 90°.

[0010] As a further aspect of the present invention: an isolation support strip is fixed on one side of the same side of the heat-conducting plate.

[0011] As a further aspect of the present invention: a square tube is fixed at the notch of the heat-conducting plate in the heat exchange unit.

[0012] To achieve the above objectives, the present invention also provides a fluid waste heat recovery heat exchange method, and a heat exchange device based on the above fluid waste heat recovery includes:

[0013] The exothermic fluid enters the horizontal fluid channel between the heat-conducting plates of the heat exchanger body from the exothermic fluid inlet. At the same time, the heat-absorbing fluid enters the vertical fluid channel between the heat-conducting plates of the heat exchanger body from the heat-absorbing fluid inlet. The two heat exchange media are isolated from each other and flow in opposite directions vertically. Heat is transferred through the heat-conducting plates to realize the heat transfer between the hot and cold fluid media and achieve waste heat recovery.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. By using structural design and processing methods such as bending the heat-conducting plates in the same direction on opposite sides and bending them in opposite directions on adjacent sides, and welding adjacent heat-conducting plates on adjacent sides, a fully welded plate heat exchanger structure is formed, replacing the traditional gasket structure plate heat exchanger. This completely solves the problems commonly found in traditional plate heat exchangers, such as high wind resistance, low pressure, limited gasket temperature resistance, and easy aging.

[0016] 2. By adjusting the bending length and angle of the heat-conducting plates, a conical windward surface can be formed, which can effectively reduce the wind resistance of the heat exchanger.

[0017] 3. By using the adjacent heat-conducting plates to weld together at their edges and by incorporating built-in isolation support bars, the pressure resistance of the heat exchange fluid channels can be effectively improved, further expanding the application pressure range of the heat exchanger.

[0018] 4. By eliminating the gasket design structure, the problems of limited gasket temperature resistance and easy aging in traditional plate heat exchangers are completely solved, further expanding the application temperature range of the heat exchanger. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the heat exchange device for fluid waste heat recovery according to the present invention.

[0020] Figure 2 This is a perspective view of the heat exchange unit of the present invention.

[0021] Figure 3 This is a left view of the heat exchange unit of the present invention.

[0022] Figure 4 This is a schematic diagram of the splicing of the heat-conducting plates of the present invention.

[0023] Figure 5 This is a schematic diagram of the structure of the heat-conducting plate of the present invention.

[0024] In the diagram: 1. Heat exchange unit, 2. Flow guide channel, 3. Heat-absorbing fluid inlet, 4. Heat-absorbing fluid outlet, 5. Heat-releasing fluid outlet, 6. Heat-releasing fluid inlet, 7. Support frame, 8. Notch, 9. Horizontal fluid channel, 10. Vertical fluid channel.

[0025] 1-1. Heat-conducting plate; 1-2. Isolation support strip; 1-3. Square tube. Detailed Implementation

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] like Figures 1 to 5 As shown, a heat exchange device for fluid waste heat recovery includes a support frame 7, on which a plurality of heat exchange units 1 are connected. The heat exchange units 1 are connected in series through a flow guide channel 2 to form a heat exchange body. The flow guide channel 2 is formed by bending plates to form an irregular channel for connecting adjacent heat exchange units 1, reducing wind resistance and facilitating gas flow.

[0028] The heat exchanger body has horizontally oriented heat-releasing fluid inlet 6 and heat-releasing fluid outlet 5 at both ends or on the same side, and vertically oriented heat-absorbing fluid inlet 3 and heat-absorbing fluid outlet 4.

[0029] The heat exchange unit 1 includes several heat-conducting plates 1-1. The heat-conducting plates 1-1 are connected to form horizontal fluid channels 9 and vertical fluid channels 10 that are spaced apart from each other and perpendicular to each other. The horizontal fluid channels 9 are connected to the heat-releasing fluid inlet 6 and the heat-releasing fluid outlet 5, and the vertical fluid channels 10 are connected to the heat-absorbing fluid inlet 3 and the heat-absorbing fluid outlet 4.

[0030] The exothermic fluid flows horizontally along the heat exchanger, while the heat-absorbing fluid flows vertically through the connecting channel, deflecting upwards and downwards.

[0031] Specifically, the exothermic fluid enters the heat exchange body through the exothermic fluid inlet 6, flows horizontally through heat exchange units 1, and finally exits through the exothermic fluid outlet 5; the heat-absorbing fluid enters the heat exchange body through the heat-absorbing fluid inlet 3, enters from the upper opening of the first heat exchange unit 1, flows vertically to the lower opening of the first heat exchange unit 1, reaches the lower opening of the next heat exchange unit 1 through the guide channel 2, passes vertically through the second heat exchange unit 1 to the upper opening of the second heat exchange unit 1, reaches the next heat exchange unit 1 through the next guide channel 2, flows vertically up and down in opposite directions, and finally exits through the heat-absorbing fluid outlet 4.

[0032] To facilitate the flow of two heat exchange gases, the heat-conducting plate 1-1 is further designed as a rectangular or square structure, with opposite sides welded together to form horizontal fluid channels 9 and vertical fluid channels 10 that are spaced apart and perpendicular to each other, allowing the two heat exchange gases to flow through. This also helps to improve the pressure resistance of the heat exchange channels formed by the horizontal fluid channels 9 and vertical fluid channels 10.

[0033] Furthermore, notches 8 are formed on the angle bisectors of the interior angles of the four corners of the heat-conducting plate 1-1. Opposite sides of the heat-conducting plate 1-1 are bent in the same direction, while adjacent sides are bent in the opposite direction, and the bending width and bending angle are the same. Preferably, the depth of the notch 8 is 1.414 times the bending width.

[0034] Furthermore, the bending width is greater than or equal to half the distance between adjacent heat-conducting plates 1-1, and the bending angle is less than or equal to 90°, which can reduce airflow resistance. The bending width of the heat-conducting plate 1-1 is 15-50mm, preferably 25-35mm, and the bending angle is 5°-10°, preferably 6°-8°. Different heat-conducting plates 1-1-1 are spliced ​​together on all four sides, and then the spliced ​​edges are welded to form alternating horizontal fluid channels 9 and vertical fluid channels 10. This simultaneously achieves the triple benefits of eliminating the gasket of the plate heat exchanger, increasing the pressure-bearing capacity of the heat exchanger, and reducing the resistance on the windward side.

[0035] To prevent deformation of adjacent heat-conducting plates 1-1, which could lead to uneven airflow, a single-sided isolation support strip 1-2 is further fixed to one side of the heat-conducting plate 1-1. The width of the isolation support strip 1-2 is the same as the distance between adjacent surfaces of the heat-conducting plates 1-1, and the spacing between the isolation support strips 1-2 on the same plane is 200-600mm, preferably 300-400mm. The isolation support strip 1-2 serves to support the heat-conducting plates 1-1 and homogenize the spacing between them, while also improving the pressure resistance of the heat exchanger channels.

[0036] Furthermore, a square tube 1-3 is fixed at the notch 8 of the heat-conducting plate 1-1 in the heat exchange unit 1. The square tube 1-3 is the same length as the heat exchange unit 1, and serves to seal the notch 8 and provide support.

[0037] Preferably, the heat-conducting plate 1-1 is made of stainless steel or titanium alloy, which has good high-temperature resistance and corrosion resistance. For special corrosive environments, a surface coating treatment can be used to further improve corrosion resistance.

[0038] The heat-conducting plates 1-1 are sealed with high-temperature corrosion-resistant sealant to prevent gas leakage. The sealant is made of silicone rubber and can work stably for a long time below 450℃.

[0039] A method for recovering waste heat from a fluid, based on the aforementioned heat exchange device for recovering waste heat from a fluid, includes:

[0040] The exothermic fluid medium enters the horizontal fluid channel 9 between the heat-conducting plates 1-1 of the heat exchange body from the exothermic fluid inlet 6. At the same time, the heat-absorbing fluid medium enters the vertical fluid channel 10 between the heat-conducting plates 1-1 of the heat exchange body from the heat-absorbing fluid inlet 3. The two heat exchange media are isolated from each other and flow in opposite directions vertically, transferring heat through the heat-conducting plates 1-1.

[0041] In this process, on the one hand, the high-temperature exothermic fluid medium enters the heat exchange body and transfers heat to the low-temperature heat-conducting plate 1-1 through heat exchange with the exothermic fluid. After absorbing heat, the temperature of the heat-conducting plate 1-1 rises, and then the heat is transferred to the adjacent heat-absorbing fluid medium through heat conduction. The exothermic fluid medium gradually becomes a low-temperature fluid medium and finally flows out from the exothermic fluid outlet 5 of the heat exchange body. On the other hand, the low-temperature heat-absorbing fluid medium enters the heat exchange body in the opposite direction and absorbs the heat of the high-temperature heat-conducting plate 1-1 through convection heat transfer, causing the temperature of the heat-conducting plate 1-1 to drop. After absorbing heat, the low-temperature heat-absorbing fluid medium becomes a high-temperature heat-absorbing fluid medium and flows out from the heat-absorbing fluid outlet 4 of the heat exchange body.

[0042] The exothermic and endothermic fluids exchange heat through the heat-conducting plate 1-1 without mixing, ultimately achieving heat transfer between the hot and cold fluid media and realizing waste heat recovery.

[0043] Among them, the exothermic fluid medium includes, but is not limited to, waste heat flue gas, waste heat air, waste heat steam, waste hot water, waste heat oil and other fluids containing a certain temperature and waste heat; the heat-absorbing fluid medium includes, but is not limited to, clean air, process water, process oil, process fuel gas, humid air and other process fluids that need to be heated.

Claims

1. A heat exchange device for fluid waste heat recovery, comprising a support frame (7), characterized in that, Several heat exchange units (1) are connected on the support frame (7), and the heat exchange units (1) are connected in series through the flow channel (2) to form a heat exchange body; The heat exchanger body has horizontally oriented heat-releasing fluid inlet (6) and heat-releasing fluid outlet (5) and vertically oriented heat-absorbing fluid inlet (3) and heat-absorbing fluid outlet (4) at both ends or on the same side. The heat exchange unit (1) includes several heat-conducting plates (1-1), which are connected to form horizontal fluid channels (9) and vertical fluid channels (10) that are spaced apart from each other and perpendicular to each other. The horizontal fluid channels (9) are connected to the heat-releasing fluid inlet (6) and the heat-releasing fluid outlet (5), and the vertical fluid channels (10) are connected to the heat-absorbing fluid inlet (3) and the heat-absorbing fluid outlet (4).

2. The heat exchange device for fluid waste heat recovery according to claim 1, characterized in that, The heat-conducting plate (1-1) has a rectangular or square structure and is welded with opposite sides to form a horizontal fluid channel (9) and a vertical fluid channel (10) that are spaced apart and perpendicular to each other to allow the two heat exchange gases to flow.

3. A heat exchange device for fluid waste heat recovery according to claim 1 or 2, characterized in that, The heat-conducting plate (1-1) has notches (8) on the inner angle bisectors of its four corners. The heat-conducting plate (1-1) is bent in the same direction on opposite sides and bent in the opposite direction on adjacent sides, with the same bending width and bending angle.

4. The heat exchange device for fluid waste heat recovery according to claim 3, characterized in that, The bending width is greater than or equal to 1 / 2 of the distance between adjacent heat-conducting plates (1-1), and the bending angle is less than or equal to 90°.

5. The heat exchange device for fluid waste heat recovery according to claim 3, characterized in that, An isolation support strip (1-2) is fixed on one side of the same side of the heat-conducting plate (1-1).

6. The heat exchange device for fluid waste heat recovery according to claim 3, characterized in that, A square tube (1-3) is fixed at the notch (8) of the heat-conducting plate (1-1) in the heat exchange unit (1).

7. A method for recovering waste heat from fluids, characterized in that, The heat exchange device for fluid waste heat recovery according to any one of claims 1-6 comprises: The exothermic fluid medium enters the horizontal fluid channel (9) between the heat-conducting plates (1-1) of the heat exchange body from the exothermic fluid inlet (6). At the same time, the heat-absorbing fluid medium enters the vertical fluid channel (10) between the heat-conducting plates (1-1) of the heat exchange body from the heat-absorbing fluid inlet (3). The two heat exchange media are isolated from each other and flow vertically in opposite directions. They transfer heat through the heat-conducting plates (1-1) to realize the heat transfer between the hot and cold fluid media and realize the recovery of waste heat.

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