A composite structure economizer
By designing a composite economizer, which combines metal plates with non-metallic heat exchange tubes, the problem of economizers in coal-fired boilers being susceptible to wear and corrosion in flue gas is solved, thereby improving heat exchange efficiency and equipment durability, and simplifying the installation and maintenance process.
Patent Information
- Application Number
- CN202423238499.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-27
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-27
AI Technical Summary
Existing economizers for coal-fired boilers are not resistant to wear and corrosion in flue gas, and have low heat exchange efficiency, resulting in low heat recovery rate and difficulties in installation and maintenance.
The economizer adopts a composite structure and utilizes a combination design of metal plates and non-metallic heat exchange tubes. The metal plates are embedded in the non-metallic heat exchange tubes, and water is circulated in the non-metallic heat exchange tubes for heat transfer. The metal plates exchange heat with the flue gas, which improves the heat exchange efficiency. Furthermore, the staggered arrangement and cleaning tube design improve the flow of flue gas and reduce ash accumulation.
It improves heat exchange efficiency, extends the service life of non-metallic heat exchange tubes, reduces installation and maintenance difficulty, and enhances the wear and corrosion resistance of the equipment.
Smart Images
Figure CN223610098U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a boiler economizer technical field especially is related to a compound structure economizer. BACKGROUND
[0002] Setting up the economizer in the flue gas passage of the coal-fired boiler can reduce the flue gas temperature, improve the thermal efficiency of the boiler and has good economic and environmental protection benefits.
[0003] The metal tube type heat exchanger represented by ND steel (including H type and finned tube) has strong acid corrosion resistance, but the corrosion factors in the flue gas are very complex. In order to ensure the safe operation of the coal-fired boiler, the flue gas temperature is usually increased to protect the economizer, so it is difficult to reduce the flue gas temperature to the extreme by using the ND steel economizer for deep flue gas cooling. When the flue gas flow rate is low, the flue gas does not flow between the fins, which is equivalent to a heat preservation layer, restricting the improvement of the heat exchange efficiency. If the flue gas flow rate is increased, the flue gas escapes from the part with the smallest resistance between the two finned tubes without effective heat exchange. At the same time, the resistance loss is large when the flue gas flow rate is increased. Therefore, the temperature difference of most tube type heat exchangers is 40-50℃. According to the 40℃ condensate water from the condenser, the flue gas temperature after passing through the heat exchanger is still 80-90℃. The waste heat of the flue gas is not fully recovered, especially the latent heat of the low-temperature water vapor. Therefore, the heat recovery efficiency is not high. Many projects can theoretically achieve 1%-2%. In actual operation, they are affected by multiple factors. The flue gas temperature after passing through the flue gas economizer is only reduced by 20-30℃, and the heat recovery rate is very low. The ND steel tube type heat exchanger has a large volume, a large area and a large weight, and is difficult to install. The tube type heat exchanger has a large resistance loss, and the original induced draft fan configuration of the power plant needs to be changed when it is replaced. The ND steel tube type heat exchanger has a large volume and a large axial length, and cannot be thoroughly cleaned. Due to the limitation of the corrosion resistance of the material, the service life of the ND steel tube flue gas economizer is generally low.
[0004] The fluoroplastic tube type heat exchanger is made of fluoroplastic tube. The corrosion resistance of the fluoroplastic tube is not a problem in the flue gas of the coal-fired boiler, but the fluoroplastic is easy to decompose under high temperature conditions above 300℃. The heat transfer coefficient of the fluoroplastic tube is lower than that of the ND steel, and the heat recovery rate is low. The installation difficulty of the fluoroplastic tube type heat exchanger is the same as that of the ND steel heat exchanger. The fluoroplastic tube type heat exchanger has a large resistance loss, and the original system balance is easily affected when it is replaced. The fluoroplastic itself has a non-stick surface, but the ash deposited between the heat exchanger tubes will form a mud ball with the entire heat exchanger after a certain period of time, which will seal the entire heat exchanger. Due to the small tube spacing and the long axial length, it is difficult to maintain and is prone to be scrapped as a whole. The service life of the plastic heat exchanger is limited by the aging and local accelerated aging of the plastic. If it is blocked, it will be scrapped prematurely.
[0005] Therefore, it is of great significance to develop a new type of economizer with a novel structure. Content of the utility model
[0006] In order to overcome the defects of the prior art, the utility model provides a composite structure economizer. The technical problems of the low corrosion resistance and abrasion resistance of the economizer in flue gas and the low heat exchange efficiency are solved, and the flue gas boiler waste heat recovery rate is effectively improved.
[0007] In order to solve the above technical problems, the composite structure economizer provided by the utility model, including the support connected with the boiler flue gas channel, a plurality of composite plate pipes connected with the support, the inlet pipe box connected with the water inlet end of the nonmetal heat exchange pipe of the composite plate pipe, the outlet pipe box connected with the water outlet end of the nonmetal heat exchange pipe of the composite plate pipe, the upper maintenance cover plate located above the composite plate pipe and connected with the boiler flue gas channel, and the lower maintenance cover plate located below the composite plate pipe and connected with the boiler flue gas channel, the composite plate pipe includes a metal plate and a nonmetal heat exchange pipe embedded in the metal plate.
[0008] As a further improved technical solution, the composite structure economizer provided by the utility model further has a cleaning pipe extending into adjacent composite plate pipes.
[0009] As a further improved technical solution, the composite structure economizer provided by the utility model has a plurality of arc-shaped cover plates connected with the metal plate, and the nonmetal heat exchange pipe is inserted into the arc-shaped groove and covered by the arc-shaped cover plate.
[0010] As a further improved technical solution, the composite structure economizer provided by the utility model has a plurality of pipe cavities arranged at intervals in the metal plate, and the nonmetal heat exchange pipe is inserted into the pipe cavity.
[0011] In the case of no conflict, the above improved solutions can be implemented alone or in combination.
[0012] The technical solution provided by the utility model solves the technical problems of the low corrosion resistance and abrasion resistance of the economizer in flue gas by embedding the nonmetal heat exchange pipe in the metal plate, and has the characteristics of compact structure, convenient installation, small maintenance difficulty and the like. BRIEF DESCRIPTION OF DRAWINGS
[0013] The accompanying drawings are included to provide a further understanding of the utility model, constitute part of the present application, and do not constitute improper limitation to the utility model. In the drawings:
[0014] Figure 1 It is the structure diagram of the example composite structure economizer.
[0015] Figure 2 is a composite plate tube arrangement diagram of an embodiment composite structure economizer;
[0016] Figure 3 is a structural diagram of an embodiment composite plate tube of a composite structure economizer;
[0017] Figure 4 is one of sectional structural diagrams of an embodiment composite plate tube of a composite structure economizer;
[0018] Figure 5 is the second of sectional structural diagrams of an embodiment composite plate tube of a composite structure economizer. DETAILED DESCRIPTION
[0019] The embodiment of the utility model will be explained in further detail below with reference to the drawings.
[0020] As Figures 1 to 3 shown in the composite structure economizer includes with the boiler flue gas passage 1 connects the support 2, a plurality of block with the support 2 connects the composite plate tube 3, with the nonmetallic heat exchange tube 4 of the composite plate tube 3's water inlet end connects the water inlet pipe course box 5, with the nonmetallic heat exchange tube 4 of the composite plate tube 3's water outlet end connects the water outlet pipe course box 6, is located in the upper of the composite plate tube 3, with the boiler flue gas passage 1 connects the upper maintenance cover plate 7, is located in the lower of the composite plate tube 3, with the boiler flue gas passage 1 connects the lower maintenance cover plate 8;Composite plate tube 3 includes metal plate 9, embeds the nonmetallic heat exchange tube 4 in the metal plate 9.
[0021] The metal plate 9 of composite plate tube 3 is made of wear-resistant, corrosion-resistant metal plate material, and the heat exchange tube 4 uses a nonmetallic tube. During operation, the metal plate 9 exchanges heat with the flue gas, the metal plate 9 transfers heat to the nonmetallic heat exchange tube 4, and the nonmetallic heat exchange tube 4 transfers heat to the water in the tube. The use of metal plate heat exchange with flue gas can greatly improve the heat exchange efficiency. The metal plate has high strength, wear resistance, corrosion resistance and high heat transfer efficiency. The nonmetallic heat exchange tube 4 is embedded in the metal plate 9, which can protect the nonmetallic heat exchange tube 4. The nonmetallic heat exchange tube 4 is filled with heat exchange water, which can reduce the temperature of the nonmetallic heat exchange tube 4, thereby improving the operating environment of the nonmetallic heat exchange tube 4 and prolonging its service life. During maintenance, the upper maintenance cover plate 7 and the lower maintenance cover plate 8 can be removed, and the entire device can be pulled out of the boiler flue gas passage 1, and the metal plate or the nonmetallic tube can be selected for replacement. The technical scheme provided by the utility model solves the technical problems of wear resistance and corrosion resistance of the economizer in the flue gas by embedding the nonmetallic heat exchange tube in the metal plate, and has the characteristics of compact structure, easy installation and small maintenance difficulty.
[0022] As Figure 2As shown in the figure, the composite plate tubes 3 are arranged in parallel and staggered in the boiler flue gas passage 1. The parallel arrangement of the composite plate tubes 3 makes the flue gas flow resistance uniform everywhere, facilitates the dispersion of flue gas into the passages between the composite plate tubes 3, and avoids the occurrence of short-circuiting wind. The staggered arrangement structure effectively disturbs the flue gas entering between two composite plate tubes 3, further improving the heat exchange efficiency. The composite plate tubes 3 are parallel to the flue gas flow direction and perpendicular to the ground, and there are few ash accumulation corners. The ash accumulation falls along the composite plate tubes 3 under the action of gravity without obstacles. At the same time, the large gap between the composite plate tubes 3 can ensure the ash falling space.
[0023] As one of the embodiments, as shown in the figure, Figure 1 The composite structure economizer also has a cleaning pipe 10 extending into the composite plate tubes 3. The provision of the cleaning pipe 10 can clean the composite plate tubes 3.
[0024] As one of the embodiments, as shown in the figure, Figure 4 The metal plate 9 of the composite structure economizer has a plurality of arc-shaped grooves 11, and the composite structure economizer also has a plurality of arc-shaped cover plates 12 connected with the metal plate 9; the non-metal heat exchange pipe 4 is arranged in the arc-shaped groove 11 and is covered by the arc-shaped cover plate 12.
[0025] As one of the embodiments, as shown in the figure, Figure 5 The metal plate 9 of the composite structure economizer is provided with a plurality of pipe cavities 13 at intervals, and the non-metal heat exchange pipe 4 is inserted into the pipe cavity 13.
[0026] The metal plate 9 is integrally formed or formed in parts. As shown in the figure, Figure 4 The integrally formed metal plate 9 has arc-shaped grooves 11 and arc-shaped bosses, which can disturb the flue gas and strengthen the heat exchange. As shown in the figure, Figure 5 The metal plate 9 formed in parts is provided with a plurality of pipe cavities 13 at intervals, and the non-metal heat exchange pipe 4 is inserted into the pipe cavity 13. The non-metal heat exchange pipe 4 can be selected from a silica gel pipe, a PE pipe, etc. In the heated state, the non-metal heat exchange pipe 4 expands due to heat, so that the non-metal heat exchange pipe 4 is tightly attached to the arc-shaped groove 11, the arc-shaped cover plate 12 or the pipe cavity 13, and the non-metal heat exchange pipe 4 is tightly attached to the metal plate, thereby obtaining a higher heat transfer efficiency. The arc-shaped bosses on the metal plate 9 effectively disturb the flue gas entering between two composite plate tubes 3, further improving the heat exchange efficiency.
[0027] Obviously, the utility model is not limited to the above preferred embodiments, and can be transformed and improved in various forms within the spirit of the utility model claim and specification, can solve the same technical problem, and achieve the expected technical effect, so it is not repeated. All the schemes that can be directly or intuitively conceived by those skilled in the art from the disclosed content of the utility model belong to the protection scope of the utility model as long as they are within the spirit of the claim.
Claims
1. A composite structure economizer, comprising a support (2) connected with a boiler flue gas passage (1), a plurality of composite plate tubes (3) connected with the support (2), a water inlet pipe passage box (5) connected with a water inlet end of a non-metal heat exchange tube (4) of the composite plate tube (3), a water outlet pipe passage box (6) connected with a water outlet end of the non-metal heat exchange tube (4) of the composite plate tube (3), an upper maintenance cover plate (7) located above the composite plate tube (3) and connected with the boiler flue gas passage (1), and a lower maintenance cover plate (8) located below the composite plate tube (3) and connected with the boiler flue gas passage (1); characterized in that, The composite plate tube (3) comprises a metal plate (9) and a non-metal heat exchange tube (4) embedded in the metal plate (9).
2. The composite structure economizer of claim 1, wherein, The composite plate tube (3) further comprises a cleaning tube (10) extending into adjacent composite plate tubes (3).
3. The composite structure economizer of claim 1, wherein, The metal plate (9) is provided with a plurality of arc-shaped grooves (11), and the composite structure economizer is further provided with a plurality of arc-shaped cover plates (12) connected with the metal plate (9); the non-metal heat exchange tube (4) is arranged in the arc-shaped grooves (11) and covered by the arc-shaped cover plates (12).
4. The composite structure economizer of claim 1, wherein, The metal plate (9) is provided with a plurality of tube cavities (13) at intervals, and the non-metal heat exchange tube (4) is inserted into the tube cavities (13).