Waste heat recovery device

Abstract

The invention relates to a waste heat recovery device which comprises a container with a closed cavity, the container is provided with an evaporation section and a condensation section, liquid capable of being evaporated after being heated is arranged in the closed cavity, the evaporation section is a flat box body, the condensation section is a cylindrical barrel, and the evaporation section and the condensation section are connected through a connection section. The two ends of the connection section are communicated with the evaporation section and the condensation section respectively. After the technical scheme is adopted, the evaporation section is the flat box body, the area of a windward side can be reduced, equipment abrasion is reduced, the service life of equipment is prolonged, the box body has a large enough side heat exchange surface, the heat exchange efficiency is improved, the condensation section adopts a cylindrical structure, the condensation section is more pressure-resistant and not easy to crack, the risk of condensed water leakage is reduced, and the service life of the equipment is prolonged. When the heat exchanger is used for heat exchange of the flue gas channel, the condensation section is arranged outside the flue gas channel, and the occupied space in the flue gas channel can be reduced.

Description

Technical Field

[0001] The invention relates to a waste heat recovery device. Background Art

[0002] Waste heat recovery devices, such as low-temperature economizers, are also called flue gas coolers, low-pressure economizers, flue gas waste heat utilization devices, etc. Generally, finned tubes or light tubes are used as heat exchange elements. Water flows through the heat exchange tubes, and the flue gas flows through the outer wall of the heat exchange tubes. Because the water temperature is lower than the flue gas temperature, the circulating water absorbs the flue gas waste heat through the heat exchange tubes. The water temperature rises while the flue gas temperature decreases. In order to achieve low-temperature and efficient dust removal of the electrostatic precipitator, most of the low-temperature economizers are arranged in front of the dust collector. The flue gas contains a lot of ash, and the heat exchange tubes are prone to wear and leakage. According to statistics, 80% of the leakage of heat exchange tubes is caused by wear of the heating surface, 15% is caused by corrosion of the heating surface, and 5% is caused by product quality problems. In recent years, in order to achieve efficient capture of smoke and SO3 by low-temperature electrostatic precipitators, low-temperature economizers are usually arranged in the ESP flue gas inlet flue. The flue gas here has not been dust-removed, the dust concentration in the flue gas is high, and the heating surface is washed by dust particles, resulting in wear and leakage of the heat exchange tubes. This phenomenon is particularly prominent in high-ash coal conditions. If not properly handled, it will cause blockage in the smoke and air system, affecting the safe operation of the unit. Ash accumulation often occurs simultaneously with leakage problems, especially when the hydrogen escape rate of the denitrification system exceeds the standard, often forming ammonium bisulfate, causing the surface of the heat exchange tube to form a hardened ash, which is difficult to clean and creates a greater risk of leakage.

[0003] In order to solve the leakage and blockage problems, devices using heat pipes for heat exchange have appeared on the market. For example, the Chinese utility model patent with the authorization announcement number CN221223474U and the name "heat pipe low temperature economizer" discloses a heat pipe low temperature economizer, including an upper water chamber, a connecting water pipe, a lower water chamber, a gravity heat pipe and a water chamber isolation plate, the gravity heat pipe includes an evaporation section on the lower side and a condensation section on the upper side, the upper water chamber and the lower water chamber are connected through the connecting water pipe, the connecting water pipe is sleeved on the outside of the gravity heat pipe, a connecting water pipe is arranged between the upper water chamber and the lower water chamber, the condensation section passes through the lower water chamber, passes through the connecting water pipe and passes out of the upper water chamber, the upper water chamber and the lower water chamber are both arranged with water chamber isolation plates, and the water chamber isolation plates and the connecting water pipe form an up and down reciprocating cooling channel.

[0004] The above patent uses heat pipes, and even if the heat pipes on the flue gas side are worn, the cooling water is not easy to leak. However, multiple heat pipes are arranged in the flue gas channel, and the windward side is larger. The leeward side of the heat pipe is prone to vortex vortex area or dead zone scaling, which increases the resistance of the flue. In order to ensure the operation of the system, the output power of the induced draft fan needs to be increased, which wastes electricity. Moreover, with this structure, the actual heat exchange area of ​​the single equipment is still small, and the efficiency is low. To exchange the same amount of heat, the heat exchange area needs to be increased, which increases investment.

[0005] Based on the above issues, the applicant conducted research, which resulted in this case. Summary of the invention

[0006] The object of the present invention is to provide a waste heat recovery device which can reduce resistance, improve heat exchange efficiency and extend the service life of the equipment.

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

[0008] A waste heat recovery device comprises a container with a closed chamber, the container has an evaporation section and a condensation section, a heated and evaporated liquid is arranged in the closed chamber, the evaporation section is a flat box body, the condensation section is a cylindrical body, the evaporation section and the condensation section are connected by a connecting section, and the two ends of the connecting section are respectively connected to the evaporation section and the condensation section.

[0009] As a preferred embodiment of the present invention, the box body includes a first plate body and a second plate body, the lower end of the first plate body and the lower end of the second plate body are connected together to form a closed end, the upper end of the first plate body and the upper end of the second plate body form an outlet end, and the connecting section is connected to the outlet end.

[0010] As a preferred embodiment of the present invention, the left end of the first plate body is connected to the right end of the second plate body, and the right end of the first plate body is connected to the right end of the second plate body.

[0011] As a preferred embodiment of the present invention, the lower end of the first plate body and the lower end of the second plate body are connected together through a bottom plate.

[0012] As a preferred embodiment of the present invention, the left end of the first plate body and the left end of the second plate body form an inverted V-shaped air guide portion or an arc-shaped air guide portion.

[0013] As a preferred embodiment of the present invention, the length of the first plate body is much greater than the distance between the first plate body and the second plate body, and the length of the second plate body is much greater than the distance between the first plate body and the second plate body.

[0014] As a preferred embodiment of the present invention, from the left end to the right end, the distance between the first plate body and the second plate body first increases and then decreases.

[0015] As a preferred embodiment of the present invention, it also includes a condensation water tank having a water inlet and a water outlet, the condensation section is located in the condensation water tank, a first perforation is provided at the lower part of the condensation water tank, and the outer wall of the container is sealedly connected to the inner wall of the first perforation.

[0016] As a preferred embodiment of the present invention, there are multiple containers, and the condensation sections of the multiple containers are arranged along the length direction of the condensation water tank.

[0017] As a preferred embodiment of the present invention, it also includes a smoke channel, a second perforation is provided on the upper part of the smoke channel, the outer wall of the container is sealedly connected to the inner wall of the second perforation, and the evaporation sections of multiple containers are arranged in parallel along the width direction of the smoke channel.

[0018] After adopting the technical solution of the present invention, the evaporation section is a flat box, which can reduce the area of ​​the windward surface, reduce equipment wear, and increase the service life of the equipment. The box has a sufficiently large side heat exchange surface to increase the heat exchange efficiency. The condensation section adopts a cylindrical tube structure, which is more pressure-resistant and not easy to crack, reducing the risk of leakage of heat exchange condensed water. When the present invention is used for heat exchange in the flue gas channel, the condensation section is placed outside the flue gas channel, which can reduce the occupied space in the flue gas channel. Furthermore, in the present invention, multiple condensation sections are arranged in the condensation water tank along the length direction, and multiple evaporation sections are arranged in parallel along the width direction of the flue gas channel. This arrangement allows the flue gas channel to accommodate more evaporation sections, improves the heat recovery efficiency, and can also reduce the width of the condensation water tank and reduce the occupied space of the condensation water tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the present invention.

[0020] Figure 2 for Figure 1 Cross-section view at AA in the middle.

[0021] Figure 3 for Figure 1 A cross-sectional view of the first embodiment along line BB.

[0022] Figure 4 for Figure 1 A cross-sectional view of the second embodiment along line BB.

[0023] Figure 5 for Figure 1 A schematic diagram of the first embodiment of the condensation section viewed from arrow C.

[0024] Figure 6 for Figure 1 A schematic diagram of the second embodiment of the condensation section viewed from arrow C.

[0025] Figure 7 It is a structural schematic diagram of another embodiment of the second plate body of the present invention.

[0026] In the figure:

[0027] Evaporation section 10 First plate 11

[0028] Second plate 12 Air guide 13

[0029] Closed chamber 14 Bottom plate 15

[0030] Connection section 20 Condensation section 30

[0031] Condensate tank 40 Water inlet 41

[0032] Water outlet 42 First perforation 43

[0033] Smoke channel 50 Second perforation 51

[0034] Heat exchange fin 60 DETAILED DESCRIPTION

[0035] In order to better understand the technical solution of the present invention, it is described in more detail below in conjunction with embodiments.

[0036] Reference Figures 1 to 7 , a waste heat recovery device, in the embodiment, the waste heat recovery device is used for recovery in the flue gas channel 50, as a low-temperature economizer, of course, the present invention is not limited to the cooling of flue gas. In the present invention, the hollow arrow in the figure indicates the flow direction of the flue gas, which can also be said to be the flow direction of the wind. The waste heat recovery device includes a container with a closed chamber 14, the container has an evaporation section 10 and a condensation section 30, and a heated evaporable liquid is provided in the closed chamber 14. In the embodiment, the liquid is water, and the amount of water added is selected according to different heat exchange requirements. A certain vacuum degree is formed in the closed chamber 14 to reduce the boiling point of water evaporation and improve the heat exchange efficiency. The evaporation section 10 is a flat box, and the condensation section 30 is a cylindrical cylinder, which is closed at the upper end and open at the lower end. The evaporation section 10 is connected to the condensation section 30 through a connecting section 20, and the two ends of the connecting section 20 are respectively connected to the evaporation section 10 and the condensation section 30. The box body of the present invention is flat, which is different from the existing tubular heat pipe, and the area of ​​the windward surface thereof is much smaller than the side surface of the box body.

[0037] As a preferred embodiment of the present invention, the box body includes a first plate body 11 and a second plate body 12, the lower end of the first plate body 11 and the lower end of the second plate body 12 are connected together to form a closed end, the upper end of the first plate body 11 and the upper end of the second plate body 12 form an outlet end, and the connecting section 20 is connected to the outlet end. In the present invention, the lower end of the connecting section 20 is connected to the flat box body, and the upper end of the connecting section 20 is connected to the cylindrical condensing section 30, and the entire connecting section 20 is a cylinder with a variable cross-section.

[0038] As a preferred embodiment of the present invention, the left end of the first plate body 11 is connected to the right end of the second plate body 12 , and the right end of the first plate body 11 is connected to the right end of the second plate body 12 .

[0039] As a preferred embodiment of the present invention, the lower end of the first plate body 11 and the lower end of the second plate body 12 are connected together through a bottom plate 15 .

[0040] As a preferred embodiment of the present invention, the left end of the first plate body 11 and the left end of the second plate body 12 form an inverted V-shaped air guide portion 13 ( Figure 3 As shown) or arc-shaped air guide portion 13 ( Figure 4 As shown in FIG. 1 , the V-shaped air guide 13 or the arc-shaped air guide 13 is the windward surface of the box. The V-shaped air guide 13 or the arc-shaped air guide 13 can be integrally formed with the first plate 11 and the second plate 12, or can be assembled separately. For example, the first plate 11, the second plate 12 and the arc-shaped air guide 13 are formed into an integral structure by flattening the tube.

[0041] As a preferred embodiment of the present invention, the length of the first plate body 11 is much greater than the spacing between the first plate body 11 and the second plate body 12, and the length of the second plate body 12 is much greater than the spacing between the first plate body 11 and the second plate body 12. In the present invention, "much greater than" may mean that the length of the first plate body 11 or the length of the second plate body 12 is more than 10 times the spacing between the first plate bodies 11. In the present invention, if the strength allows and the space of the smoke channel 50 allows, the lengths of the first plate body 11 and the second plate body 12 may be lengthened as much as possible, while the spacing between the first plate body 11 and the second plate body 12 may be reduced. In an embodiment, the first plate body 11 and the second plate body 12 may be made of stainless steel.

[0042] As a preferred embodiment of the present invention, from the left end to the right end, the distance between the first plate body 11 and the second plate body 12 first increases and then decreases.

[0043] As a preferred embodiment of the present invention, a condensation water tank 40 is further included. The condensation water tank 40 is in a rectangular parallelepiped shape and has a water inlet 41 and a water outlet 42. The condensation section 30 is located in the condensation water tank 40. A first perforation 43 is provided at the lower portion of the condensation water tank 40. The outer wall of the container is sealed to the inner wall of the first perforation 43. For example, the gap between the two can be sealed by welding to prevent water leakage in the condensation water tank 40. During heat exchange, condensation water enters from the water inlet 41 and flows out from the water outlet 42. The condensation water takes away the heat of the condensation section 30. The gaseous substances in the condensation section 30 cool down to form a liquid and flow back to the evaporation section 10.

[0044] As a preferred embodiment of the present invention, there are multiple containers, and the condensation sections 30 of the multiple containers are arranged along the length direction of the condensation water tank 40. In an embodiment, the central axes of the condensation sections 30 are located in the same plane.

[0045] As a preferred embodiment of the present invention, it also includes a flue gas channel 50, which is located below the condensation water tank 40. A second perforation 51 is provided on the upper part of the flue gas channel 50. The outer wall of the container is sealed and connected to the inner wall of the second perforation 51. For example, the gap between the two can be sealed by welding to prevent flue gas leakage. The evaporation sections 10 of the multiple containers are arranged in parallel along the width direction of the flue gas channel 50, that is, the evaporation sections 10 are arranged along the width direction of the condensation water tank 40. The present invention arranges the evaporation sections 10 in parallel and the condensation sections 30 in a straight line through the different directions of the connecting sections 20 in each container, thereby reducing the volume of the water tank, reducing the impact of water pressure on the condensation section 30, and ensuring that the evaporation section 10 in the flue gas channel 50 has sufficient heat exchange area, thereby improving heat exchange efficiency and ensuring the life of the equipment.

[0046] As a preferred embodiment of the present invention, in order to improve the heat dissipation effect of the first plate body 11 and the second plate body 12, heat exchange fins 60 may be further provided on the first plate body 11 and the second plate body 12, for example Figure 7 It is shown that heat exchange fins 60 are arranged on the second plate body 12. By arranging the heat exchange fins 60, the heat exchange area is further increased to improve the heat exchange efficiency. In the embodiment, there are multiple heat exchange fins 60, and the multiple heat exchange fins 60 extend along the length direction of the second plate body 12. The multiple heat exchange fins 60 are arranged along the height direction of the second plate body 60. An airflow channel is formed between adjacent heat exchange fins 60. The heat of the flue gas is transferred to the second plate body 12 through the heat exchange fins 60, and then transmitted to the evaporation section.

[0047] The protection scope of the present invention is not limited to this embodiment, and any person making similar changes thereto shall be deemed to be within the protection scope of the present invention.

Claims

1. A waste heat recovery device, comprising a container with a closed chamber, the container having an evaporation section and a condensation section, and a heated evaporable liquid is arranged in the closed chamber, characterized in that: The evaporation section is a flat box body, the condensation section is a cylindrical body, the evaporation section and the condensation section are connected through a connecting section, and two ends of the connecting section are respectively connected to the evaporation section and the condensation section.

2. A waste heat recovery device according to claim 1, characterized in that: The box body includes a first plate body and a second plate body, the lower end of the first plate body and the lower end of the second plate body are connected together to form a closed end, the upper end of the first plate body and the upper end of the second plate body form an outlet end, and the connecting section is connected to the outlet end.

3. A waste heat recovery device according to claim 2, characterized in that: The left end of the first plate body is connected to the right end of the second plate body, and the right end of the first plate body is connected to the right end of the second plate body.

4. A waste heat recovery device according to claim 3, characterized in that: The lower end of the first plate body and the lower end of the second plate body are connected together through a bottom plate.

5. A waste heat recovery device according to claim 3, characterized in that: The left end of the first plate body and the left end of the second plate body form an inverted V-shaped air guide portion or an arc-shaped air guide portion.

6. A waste heat recovery device according to claim 3, characterized in that: The length of the first plate body is much greater than the distance between the first plate body and the second plate body, and the length of the second plate body is much greater than the distance between the first plate body and the second plate body.

7. A waste heat recovery device according to claim 3, characterized in that: From the left end to the right end, the distance between the first plate body and the second plate body first increases and then decreases.

8. The waste heat recovery device according to claim 1, characterized in that: It also includes a condensation water tank having a water inlet and a water outlet. The condensation section is located in the condensation water tank. A first perforation is provided at the lower part of the condensation water tank. The outer wall of the container is sealedly connected to the inner wall of the first perforation.

9. A waste heat recovery device according to claim 8, characterized in that: There are multiple containers, and the condensation sections of the multiple containers are arranged along the length direction of the condensation water tank.

10. A waste heat recovery device according to claim 9, characterized in that: It also includes a smoke channel, a second perforation is provided on the upper part of the smoke channel, the outer wall of the container is sealed and connected to the inner wall of the second perforation, and the evaporation sections of the multiple containers are arranged in parallel along the width direction of the smoke channel.

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