Exhaust heat recovery device with external air pipe
By using an externally mounted exhaust heat recovery device with counter-current heat exchange technology, the problems of high cost and difficulty in retrofitting existing devices have been solved, achieving low-cost and sustainable heat recovery and heating to meet production needs.
Patent Information
- Application Number
- CN202423049744.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-11-04
- Estimated Expiration
- 2034-12-11
AI Technical Summary
Existing boiler flue gas and high-temperature process waste gas heat recovery devices are costly to manufacture and difficult to retrofit, leading to production stoppages and inability to operate continuously.
Design an externally mounted exhaust heat recovery device, including an inner wall, an outer wall, and coil fins to form a closed cavity. Heat is recovered through counter-current heat exchange. Stainless steel and high heat transfer performance materials are used. The device is supported by a hanging bracket, and the circulating water flows counter-currently with the exhaust air for heat exchange.
It reduced the difficulty and cost of the transformation, ensured continuous production, extended the life of the equipment, provided a cheap and stable hot water source, and achieved energy conservation and emission reduction.
Smart Images
Figure CN223512555U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to boiler flue gas and process high-temperature waste gas exhaust heat recovery technology, and in particular to an externally mounted exhaust heat recovery device. Background Technology
[0002] Currently, the main method for heat recovery from boiler flue gas and high-temperature process exhaust gas is to modify the flue gas ducts and process exhaust ducts, adding heat recovery devices to these ducts to recover heat. However, this method has two problems: first, the flue gas or exhaust gas in the ducts contains a lot of acidic corrosive components, which places strict requirements on the materials and processes of the heat exchangers, often resulting in high manufacturing costs for the heat recovery devices; second, modifying the ducts requires stopping the process operation, leading to a halt in normal production and affecting the company's economic benefits. In some cases, the company simply cannot stop the production process, making the heat recovery modification project impossible to implement.
[0003] In view of this, this application aims to design an external duct exhaust heat recovery device. This heat recovery device is added to the outside of the duct without the need to cut off the duct for modification, which can greatly reduce the difficulty of heat recovery modification work, avoid the interruption of process production, and also greatly reduce product manufacturing costs. Utility Model Content
[0004] The technical problem this application aims to solve is that existing duct heat recovery systems (boiler flue gas heat recovery, process high-temperature waste gas heat recovery) suffer from high equipment manufacturing costs, difficulties in process modification, and even the inability to modify them.
[0005] To solve the above-mentioned technical problems, this application provides an externally mounted exhaust heat recovery device, comprising: an inner wall, fitted onto the outer wall of the exhaust duct, the cross-section of the inner wall matching the cross-section of the exhaust duct; an outer wall, surrounding the outer periphery of the inner wall and forming a closed cavity with the inner wall; and coil fins, disposed within the closed cavity between the inner wall and the outer wall; wherein, the closed cavity is fitted onto the outer periphery of the exhaust duct, and along the arrangement direction of the exhaust duct, a liquid injection pipe is installed at one end of the closed cavity and a liquid drain pipe is installed at the other end.
[0006] According to an embodiment of this application, both the injection pipe and the drainage pipe are connected to a circulation pump.
[0007] According to an embodiment of this application, the water in the injection pipe flows through the closed cavity towards the water flow direction of the drain pipe, which is opposite to the direction of the hot air flowing in the exhaust duct, forming countercurrent heat exchange to improve the heat exchange effect.
[0008] According to the embodiments of this application, both the inner and outer walls are made of 304 stainless steel, and the coil fins in the middle are made of copper or aluminum fins with high heat transfer performance.
[0009] According to an embodiment of this application, the two ends of the inner wall are respectively connected to the two ends of the outer wall at the end, and the connection is provided with a sealing plug for sealing.
[0010] According to embodiments of this application, valves are provided on both the injection pipe and the drainage pipe.
[0011] According to an embodiment of this application, the drain pipe outputs low-temperature hot water through a pipeline, and the low-temperature hot water is heated by a water source heat pump and then supplied for process water, domestic hot water or heating.
[0012] According to an embodiment of this application, the exhaust heat recovery device is further equipped with a hanger device, which includes a fixed rod and a lifting rod. The fixed rod passes through the bottom of the outer wall and is fixed to the outer wall, and the lifting rod is vertically fixed at both ends of the fixed rod.
[0013] According to an embodiment of this application, a lifting assembly is provided on the upper part of the lifting rod.
[0014] According to an embodiment of this application, the fixing rod is welded to the outer wall.
[0015] According to an embodiment of this application, the enclosed cavity is a rectangular frame.
[0016] Compared with the prior art, the technical solution of this application has the following beneficial effects:
[0017] 1. The heat recovery device of this application can be separately installed around the outer periphery of the exhaust duct. Compared with the prior art, this application does not require cutting off and modifying the operating process exhaust duct, and will not cause the process production to stop, thus ensuring continuous operation. Since the heat recovery device does not come into direct contact with the process waste gas, the degree of corrosion of the heat recovery device is reduced, greatly extending the service life of the product and ensuring its reliable, stable and efficient performance.
[0018] 2. The heat recovery device of this application is a complete sealed cavity with inlet and outlet water pipes at both ends. It contains circulating water. The recovered low-temperature waste heat can be transported to the water source heat pump to produce medium-temperature hot water for production, living and heating purposes, thereby obtaining a cheap and stable hot water source. The exhaust heat recovery device fully reflects its economic value and environmental benefits, and helps to achieve certain energy conservation and emission reduction goals.
[0019] 3. The process described in this application is simple to manufacture and has low cost. Attached Figure Description
[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.
[0021] Figure 1This is a schematic diagram of the structure of an externally mounted exhaust heat recovery device according to an example of this utility model;
[0022] Figure 2 This is a test diagram of an externally mounted exhaust heat recovery device, which is an example of this utility model.
[0023] The annotations in the attached figures are explained as follows:
[0024] 1. Exhaust duct, 10. Inner wall, 11. Coil fins, 20. Outer wall, 30. Enclosed cavity, 31. Injection pipe, 32. Drain pipe, 41. Fixing rod, 42. Lifting rod. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0026] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a,” and similar terms, do not indicate a limitation of quantity, but rather indicate the presence of at least one.
[0027] Figure 1 This is a schematic diagram illustrating the structure of an externally mounted exhaust heat recovery device, which is an example of this utility model. Figure 2 This is a test diagram of an externally mounted exhaust heat recovery device according to an example of this utility model, wherein... Figure 1 , Figure 2 The sealing plug is not shown.
[0028] like Figure 1 and Figure 2As shown, this utility model exemplifies an externally mounted exhaust heat recovery device, comprising an inner wall 10 fitted around the outer wall 20 of an exhaust duct 1, an outer wall 20 surrounding the inner wall 10 and forming a closed cavity 30 with the inner wall 10, and coiled fins 11 disposed within the closed cavity 30. A liquid injection pipe 31 is installed at one end of the closed cavity 30, and a liquid drain pipe 32 is installed at the other end for circulating water within the closed cavity. Compared to existing duct heat recovery (boiler flue gas heat recovery, process high-temperature waste gas heat recovery) devices, which suffer from high manufacturing costs and difficulties or even impossibilities in process modification, this application is integrally fitted onto the outside of the exhaust duct 1, eliminating the need for duct cutting and modification. This significantly reduces the difficulty of heat recovery modification work, avoids production stoppages, and substantially reduces product manufacturing costs.
[0029] In this embodiment, the inner wall 10 is fitted onto the outer wall of the exhaust duct 1, and the cross-section of the inner wall 10 matches the cross-section of the exhaust duct 1. For example... Figure 1 As shown, the inner wall 10 is arranged along the outer wall of the exhaust duct 1 to form an enclosure. As the heat exchange inner wall 10, it has sufficient stable rigidity and strength to ensure that it can fully bear the weight of the upper coil fins 11 and the outer wall 20 without crushing the outer wall of the duct that it is in contact with.
[0030] In this embodiment, the outer wall 20 surrounds the outer periphery of the inner wall 10 and forms a closed cavity 30 with the inner wall 10. For example... Figure 1 and Figure 2 As shown, the outer wall 20 is arranged along the outer periphery of the inner wall 10 to form an enclosure and is spaced a certain distance from the inner wall 10. The two ends of the enclosure of the inner wall 10 are respectively connected to the two ends of the enclosure of the outer wall 20, and the connection is provided with a sealing plug for sealing, thereby forming a closed cavity 30 between the inner wall 10 and the outer wall 20. At the same time, the shape of the enclosure of the outer wall 20 can be the same as the shape of the enclosure of the inner wall 10, or it can be different.
[0031] Specifically, both the inner wall 10 and the outer wall 20 are made of 304 stainless steel.
[0032] In this embodiment, the coil fins 11 are evenly arranged in the closed cavity 30 between the inner wall 10 and the outer wall 20. The coil fins are made of copper or aluminum with high heat transfer performance. The inner wall 10 and the coil fins 11 in the middle of the heat recovery device have a high heat transfer coefficient, ensuring that waste heat in the exhaust air or smoke can be recovered as much as possible.
[0033] In this embodiment, the enclosed cavity 30 is fitted around the outer periphery of the exhaust duct 1. Along the arrangement direction of the exhaust duct 1, one end of the enclosed cavity 30 is equipped with an injection pipe 31 and the other end is equipped with a drain pipe 32. Both the injection pipe 31 and the drain pipe 32 are equipped with valves, and the injection pipe 31 and the drain pipe 32 can be connected to the same water pump.
[0034] Specifically, the water flowing through the injection pipe 31 flows through the closed cavity 30 towards the drain pipe 32 in the opposite direction to the hot air flowing in the exhaust duct 1. The circulating water in the heat recovery device enters the coil fin 11 plate through the inlet of the injection pipe 31, forming a counter-current flow for heat exchange with the air duct, thereby increasing the system's heat transfer coefficient and improving the heat exchange effect. After absorbing the heat from the exhaust air, the water leaves the heat recovery device through the drain pipe 32.
[0035] Specifically, the drain pipe 32 is connected via a pipeline to a process water, domestic hot water, or heating water system. This heat recovery device recovers medium- and low-temperature waste heat, and the recovered heat can drive a water source heat pump for secondary heating to provide process heat, domestic hot water, and heating.
[0036] Specifically, due to its considerable weight, the heat recovery unit requires additional support brackets. The exhaust heat recovery unit is also equipped with support brackets, which include a fixing rod 41 and a lifting rod 42. The fixing rod 41 passes through the bottom of the outer wall 20 and is fixed to it. The lifting rod 42 is vertically fixed to both ends of the fixing rod 41. The upper part of the lifting rod 42 is equipped with a lifting assembly, and the fixing rod 41 can be welded to the outer wall 20.
[0037] Specifically, such as Figure 2 As shown, the closed cavity 30 has a rectangular frame.
[0038] The working principle of an externally mounted exhaust heat recovery device in this embodiment is as follows: High-temperature exhaust air from the process flows through the heat recovery device area within the exhaust duct 1. Heat exchange occurs through the outer wall 20 of the exhaust duct 1, the inner wall 10 of the heat recovery device, and the fins within the heat recovery device. Ultimately, the low-temperature heat is transferred to the circulating water within the heat recovery device for heat recovery. Simultaneously, this process also helps cool the exhaust air within the duct, improving the ambient temperature of the work area and ultimately reducing the temperature of the exhaust gas discharged outdoors, effectively protecting the environment. The circulating water within the heat recovery device enters the coil fins 11 through the injection pipe 31, forming a counter-current flow with the duct for heat exchange. This increases the system's heat transfer coefficient and improves the heat exchange effect. After absorbing heat from the exhaust air, the water flows out of the heat recovery device through the drain pipe 32. This heat recovery device recovers medium- and low-temperature waste heat. The recovered heat can drive a water source heat pump for secondary heating, providing process heat, domestic hot water, and heating.
[0039] In summary, the technical solution of this application has the following beneficial effects:
[0040] 1. The heat recovery device of this application can be separately installed around the outer periphery of the exhaust duct. Compared with the prior art, this application does not require cutting off and modifying the operating process exhaust duct, and will not cause the process production to stop, thus ensuring continuous operation. Since the heat recovery device does not come into direct contact with the process waste gas, the degree of corrosion of the heat recovery device is reduced, greatly extending the service life of the product and ensuring its reliable, stable and efficient performance.
[0041] 2. The heat recovery device of this application is a complete sealed cavity with inlet and outlet water pipes at both ends. It contains circulating water. The recovered low-temperature waste heat can be transported to the water source heat pump to produce medium-temperature hot water for production, living and heating purposes, thereby obtaining a cheap and stable hot water source. The exhaust heat recovery device fully reflects its economic value and environmental benefits, and helps to achieve certain energy conservation and emission reduction goals.
[0042] 3. The process described in this application is simple to manufacture and has low cost.
[0043] The above are merely exemplary embodiments of this application and are not intended to limit the scope of protection of this application, which is determined by the appended claims.
Claims
1. A duct-mounted exhaust heat recovery device, characterized in that, include: The inner wall is fitted onto the outer wall of the exhaust duct, and the cross-section of the inner wall matches the cross-section of the exhaust duct. An outer wall surrounds the outer periphery of the inner wall and forms a closed cavity with the inner wall; The coil fins are disposed within the enclosed cavity between the inner and outer walls; The enclosed cavity is fitted around the outer periphery of the exhaust duct. Along the arrangement direction of the exhaust duct, an injection pipe is installed at one end of the enclosed cavity and a drainage pipe is installed at the other end.
2. The externally mounted exhaust heat recovery device according to claim 1, characterized in that, Both the injection pipe and the drainage pipe are connected to a circulation pump.
3. The duct-mounted external exhaust heat recovery device according to claim 1, characterized in that, Both the inner and outer walls are made of 304 stainless steel.
4. The duct-mounted external exhaust heat recovery device according to claim 1, characterized in that, The two ends of the inner wall are respectively connected to the two ends of the outer wall at the end, and the connection is provided with a sealing plug for airtightness.
5. The externally mounted exhaust heat recovery device according to claim 1, characterized in that, Both the injection pipe and the drainage pipe are equipped with valves.
6. The externally mounted exhaust heat recovery device according to claim 1, characterized in that, The drain pipe outputs low-temperature hot water through a pipeline. The low-temperature hot water is heated by a water source heat pump and then supplied as process water, domestic hot water, or heating.
7. The externally mounted exhaust heat recovery device according to claim 1, characterized in that, Furthermore, the exhaust heat recovery device is also equipped with a hanger device, which includes a fixed rod and a lifting rod. The fixed rod passes through the bottom of the outer wall and is fixed to the outer wall, and the lifting rod is vertically fixed to both ends of the fixed rod.
8. The externally mounted exhaust heat recovery device according to claim 7, characterized in that, The upper part of the hoisting rod is equipped with a hoisting assembly.
9. The duct-mounted external exhaust heat recovery device according to claim 7, characterized in that, The fixing rod is welded and fixed to the outer wall.
10. The duct-mounted external exhaust heat recovery device according to claim 1, characterized in that, The enclosed cavity has a rectangular frame.