Novel low-temperature economizer of top finned heat exchanger
By using the staggered arrangement of the top fin heat exchanger and the wide channel plate heat exchanger in the low-temperature economizer, the problem of the boiler being unable to operate normally due to the accumulation of ash in the flue, the efficient steam water heat exchange and zero leakage of condensed water are achieved, and the energy efficiency and safety of the boiler are improved.
Patent Information
- Application Number
- CN202421901808.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-05-23
- Estimated Expiration
- 2034-08-07
AI Technical Summary
In the low-temperature economizers of existing coal-fired power plants, the flue is prone to ash accumulation, which causes the boiler to fail to operate normally.
The new low-temperature economizer adopts the top fin heat exchanger. The top fin soda and water heat exchanger are arranged staggeredly with the fin tube and heat exchanger inside the lower wide channel plate heat exchanger to improve heat exchange efficiency, and by optimizing the pipeline design and strengthening the sealing, ensuring that the condensate does not leak during the flow process.
It improves the heat exchange efficiency of steam water, avoids the vaporization of condensate due to contact with high-temperature flue gas, reduces the risk of steam leakage, achieves zero leakage of condensate, reduces water resource waste and environmental pollution, and improves the overall energy efficiency of the boiler.
Smart Images
Figure CN222895122U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of environmental protection and energy saving, and specifically relates to a novel low-temperature economizer of a top fin type heat exchanger. Background Art
[0002] Low-temperature economizer is a device that can effectively save coal and improve boiler efficiency in the low-temperature section. It is mainly used in the medium and low-temperature sections of the air preheater outlet of large boilers in power plants, thermal power plants, etc. It can effectively reduce the exhaust gas thermal efficiency by recovering the flue gas waste heat to heat the boiler feed water. Low-temperature economizer is usually installed in the tail flue at the outlet of the boiler air preheater. It can not only improve the efficiency of electrostatic precipitator and meet low emission requirements, but also reduce power consumption and reduce the specifications of downstream equipment. At the same time, it can remove most of the acid gases.
[0003] Most of the existing low-temperature economizers in coal-fired power plants use finned tubes. Since the heat medium water is directly introduced into the heat exchange tubes, after the heat exchange tubes are worn, the heat medium water will leak directly into the flue, causing serious ash accumulation, affecting the normal operation of the boiler smoke and air system, and even causing the boiler system to shut down, resulting in poor operating safety.
[0004] Therefore, a new type of low-temperature economizer with a top finned heat exchanger is needed to solve the problem in the prior art that the flue is prone to ash accumulation, resulting in the inability of the boiler to operate normally. Utility Model Content
[0005] The utility model aims to provide a novel low-temperature economizer of a top fin type heat exchanger to solve the problems raised in the above background technology.
[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a new type of low-temperature economizer with a top finned heat exchanger, comprising an inlet pipe, an inlet header, an outlet pipe and an outlet header, the inlet pipe is installed on the right side of the inlet header, the outlet pipe is installed on the left side of the outlet header, a top finned steam-water heat exchanger is installed between the inlet header and the outlet header, a water collecting tank is installed at the bottom of the top finned steam-water heat exchanger, a wide channel plate heat exchanger is installed at the bottom of the top finned steam-water heat exchanger, a heat medium water tank is installed at the bottom of the wide channel plate heat exchanger, and a downcomer is connected between the upper part of the heat medium water tank and the water collecting tank.
[0007] It should be noted in the scheme that a plurality of fin tubes communicating with the water inlet header and the water outlet header are installed in the top finned steam-water heat exchanger.
[0008] It is further worth noting that a plurality of heat exchange fins arranged at equal intervals are arranged inside the wide channel plate heat exchanger.
[0009] It should be further explained that the fin tubes in the top fin type steam-water heat exchanger and the heat exchange fins in the top fin type steam-water heat exchanger are arranged staggered.
[0010] As a preferred embodiment, the water collecting tank is arranged to be higher on the left and lower on the right.
[0011] Compared with the prior art, the novel low-temperature economizer of a top fin heat exchanger provided by the utility model has at least the following beneficial effects:
[0012] By staggering the finned tubes and heat exchange plates inside the top finned steam-water heat exchanger and the lower wide-channel plate heat exchanger, the steam-water heat exchange efficiency is increased by 1.2-1.5 times compared to the top bare tube heat exchanger. At the same time, when the boiler condensate flows through the top finned steam-water heat exchanger, it does not directly contact the flue gas generated by the boiler, which avoids the condensate from vaporizing due to contact with high-temperature flue gas, thereby reducing steam leakage that may be caused by vaporization. In the top finned steam-water heat exchanger, the condensate only exchanges heat with the top water vapor generated by the boiler. This heat exchange process is gentle and efficient, because the temperature difference between the water vapor and the condensate is small, which is conducive to the stable transfer of heat. The design of the condensate pipeline fully considers the sealing to ensure the cooling Condensate will not leak due to pipe rupture or loose connections during the flow process. The structural design and material selection of the top finned steam-water heat exchanger also reduce the risk of leakage due to thermal stress or corrosion. Since the condensed water does not come into direct contact with the flue gas and only exchanges heat with the top water vapor, there is no risk of condensed water being contaminated or vaporized during the entire process. By optimizing the pipeline design and strengthening the sealing, it can be ensured that the condensed water flows directly and completely back to the condensate outlet pipe after heating, thereby achieving zero leakage of condensed water. Zero leakage of condensed water not only reduces the waste of water resources, but also avoids environmental pollution caused by leakage. At the same time, since the heat is effectively utilized, the overall energy efficiency of the boiler is improved and energy consumption is reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;
[0014] Figure 2 This is a front view structural schematic diagram of the utility model;
[0015] Figure 3 for Figure 2 AA cutaway structural schematic diagram of the utility model.
[0016] In the figure: 1. Water inlet pipe; 2. Water inlet header; 3. Water outlet pipe; 4. Water outlet header; 5. Top finned steam-water heat exchanger; 6. Wide channel plate heat exchanger; 7. Heat medium water tank; 8. Downcomer; 9. Water collecting tank. DETAILED DESCRIPTION
[0017] The present invention will be further described below in conjunction with the embodiments.
[0018] See also Figure 1-3 The utility model provides a novel low-temperature economizer with a top finned heat exchanger, comprising an inlet pipe 1, an inlet header 2, an outlet pipe 3 and an outlet header 4, the inlet pipe 1 is installed on the right side of the inlet header 2, the outlet pipe 3 is installed on the left side of the outlet header 4, a top finned steam-water heat exchanger 5 is installed between the inlet header 2 and the outlet header 4, a water collecting tank 9 is installed at the lower part of the top finned steam-water heat exchanger 5, a wide channel plate heat exchanger 6 is installed at the lower part of the top finned steam-water heat exchanger 5, a heat medium water tank 7 is installed at the bottom of the wide channel plate heat exchanger 6, and a downcomer 8 is connected between the upper part of the heat medium water tank 7 and the water collecting tank 9.
[0019] When the boiler condensate flows through the top finned steam-water heat exchanger 5, it does not directly contact the flue gas generated by the boiler, which prevents the condensate from being vaporized due to contact with the high-temperature flue gas, thereby reducing the steam leakage that may be caused by vaporization. In the top finned steam-water heat exchanger 5, the condensate only exchanges heat with the top water vapor generated by the boiler. This heat exchange process is gentle and efficient, because the temperature difference between the water vapor and the condensate is small, which is conducive to the stable transfer of heat. The design of the condensate pipeline fully considers the sealing performance, ensuring that the condensate will not leak due to pipeline rupture or loose connection during the flow process. 5. The structural design and material selection also reduce the risk of leakage caused by thermal stress or corrosion. Since the condensed water does not come into direct contact with the flue gas and only exchanges heat with the top water vapor, there is no risk of condensed water being contaminated or vaporized during the whole process. By optimizing the pipeline design and strengthening the sealing, it can be ensured that the condensed water flows directly and completely back to the condensate outlet pipe after heating, thereby achieving zero leakage of condensed water. Zero leakage of condensed water not only reduces the waste of water resources, but also avoids environmental pollution caused by leakage. At the same time, since the heat is effectively utilized, the overall energy efficiency of the boiler is improved and energy consumption is reduced.
[0020] Further as Figure 2 and Figure 3 As shown, it is worth explaining in detail that a plurality of fin tubes communicating with the water inlet header 2 and the water outlet header 4 are installed in the top finned steam-water heat exchanger 5, a plurality of heat exchange fins arranged at equal intervals are arranged inside the wide channel plate heat exchanger 6, and the finned tubes in the top finned steam-water heat exchanger 5 and the heat exchange fins in the top finned steam-water heat exchanger 5 are staggered.
[0021] The design of the finned tube increases the heat transfer area outside the tube, allowing more heat exchange per unit volume. The small inclined holes on the finned tube allow steam to be sprayed in at high speed, which has a strong ejection effect on the surrounding cold water, enhancing the mixing and heat exchange between the cold and hot fluids. The plate heat exchanger is assembled from plates pressed from thin metal plates. The corrugated plates increase the heat transfer area, and the flow of the fluid between the plates is parallel, which is conducive to countercurrent design, improves the logarithmic mean temperature difference, and thus enhances the heat exchange efficiency. The top finned steam-water heat exchanger and the lower wide channel plate The finned tubes and heat exchange plates inside the heat exchanger 6 are staggered. This layout can avoid short circuits or bypasses between the cold and hot fluids during the flow process, ensuring that the fluids fully flow and exchange heat in their respective flow channels. The staggered arrangement also helps to reduce dead corners and insufficient heat exchange areas of the fluid inside the heat exchanger, thereby improving the overall heat exchange efficiency. The finned tubes and heat exchange plates inside the top finned steam-water heat exchanger 5 and the lower wide-channel plate heat exchanger 6 are staggered, and the steam-water heat exchange efficiency is increased by 1.2-1.5 times compared with the top bare tube heat exchanger.
[0022] Further as Figure 1 and Figure 2 As shown, it is worth explaining in detail that the water collecting tank 9 is arranged to be higher on the left and lower on the right, which helps to quickly guide and converge the condensed water droplets and realize reflux through the downcomer 8, thereby improving the reflux efficiency and facilitating the circulation work.
[0023] This scheme has the following working process: when in use, first, the waste heat flue gas at the outlet of the air preheater passes through the wide channel plate heat exchanger 6 to transfer the waste heat to the heat exchange plate, and then, the heat medium water in the heat medium water tank 7 changes into a steam-water mixture after heat exchange in the wide channel plate heat exchanger 6, and rises until it becomes water vapor and enters the top water inlet header 2 and the water outlet header 4. The water vapor condenses after heat exchange with the top finned steam-water heat exchanger 5, and the water vapor becomes condensed water droplets, which flow back to the water collection tank 9 through the inclined plates at the bottom of the top water inlet header 2 and the water outlet header 4. The heat medium in the water collection tank 9 The water utilizes the density difference and flows back to the bottom heat medium water tank 7 through the gravity of the downcomer 8. The water in the heat medium water tank 7 utilizes the density difference between the downcomer 8 and the hot plate, and enters the heat exchange plate for heating under the combined action of the rising force of the hot plate bubbles and part of the capillary condensation liquid film force. From then on, the heat medium water forms a cycle. Finally, the boiler condensate passes through the top finned steam-water heat exchanger 5, is heated and directly returns to the condensate outlet pipe 3. Since the boiler condensate pipe does not contact the flue gas, it only exchanges heat with the top water vapor, and there is no risk of leakage, so the boiler condensate can be zero-leaked.
[0024] In summary: by staggering the fin tubes and heat exchange plates inside the top finned steam-water heat exchanger 5 and the lower wide-channel plate heat exchanger 6, the steam-water heat exchange efficiency is increased by 1.2-1.5 times compared with the top bare tube heat exchanger. At the same time, when the boiler condensate flows through the top finned steam-water heat exchanger 5, it does not directly contact the flue gas generated by the boiler, which avoids the condensate from being vaporized due to contact with high-temperature flue gas, thereby reducing steam leakage that may be caused by vaporization. In the top finned steam-water heat exchanger 5, the condensate only exchanges heat with the top water vapor generated by the boiler. This heat exchange process is gentle and efficient, because the temperature difference between the water vapor and the condensate is small, which is conducive to the stable transfer of heat. The design of the condensate pipeline fully considers the sealing performance to ensure It ensures that the condensed water will not leak due to pipe rupture or loose connection during the flow process. The structural design and material selection of the top finned steam-water heat exchanger 5 also reduce the risk of leakage caused by thermal stress or corrosion. Since the condensed water is not in direct contact with the flue gas and only exchanges heat with the top water vapor, there is no risk of condensed water being contaminated or vaporized in the whole process. By optimizing the pipeline design and strengthening the sealing, it can be ensured that the condensed water flows directly and completely back to the condensate outlet pipe after heating, thereby achieving zero leakage of condensed water. Zero leakage of condensed water not only reduces the waste of water resources, but also avoids environmental pollution caused by leakage. At the same time, since the heat is effectively utilized, the overall energy efficiency of the boiler is improved and energy consumption is reduced.
Claims
1. A novel low-temperature economizer with a top finned heat exchanger, comprising a water inlet pipe (1), a water inlet header (2), a water outlet pipe (3) and a water outlet header (4), characterized in that: The water inlet pipe (1) is installed on the right side of the water inlet header (2), and the water outlet pipe (3) is installed on the left side of the water outlet header (4). A top finned steam-water heat exchanger (5) is installed between the water inlet header (2) and the water outlet header (4). A water collecting tank (9) is installed at the bottom of the top finned steam-water heat exchanger (5). A wide channel plate heat exchanger (6) is installed at the bottom of the top finned steam-water heat exchanger (5). A heat medium water tank (7) is installed at the bottom of the wide channel plate heat exchanger (6). A downcomer (8) is connected between the upper part of the heat medium water tank (7) and the water collecting tank (9).
2. A novel low-temperature economizer with a top finned heat exchanger according to claim 1, characterized in that: A plurality of fin tubes communicating with the water inlet header (2) and the water outlet header (4) are installed in the top finned steam-water heat exchanger (5).
3. A novel low-temperature economizer with a top finned heat exchanger according to claim 1 or 2, characterized in that: The wide channel plate heat exchanger (6) is provided with a plurality of heat exchange fins arranged at equal intervals inside.
4. A novel low-temperature economizer with a top fin heat exchanger according to claim 3, characterized in that: The finned tubes inside the top finned steam-water heat exchanger (5) and the heat exchange fins inside the top finned steam-water heat exchanger (5) are arranged in a staggered manner.
5. The novel low-temperature economizer of a top finned heat exchanger according to claim 1, characterized in that: The water collecting tank (9) is arranged with the left side higher and the right side lower.