Steam generator
By incorporating heat insulation components and fins into the steam generator and optimizing the flue gas flow path, the problem of easy dry burning in the vapor zone of the heat exchange tubes was solved, extending service life, reducing maintenance rate and energy consumption, and realizing a highly efficient miniaturized steam generator.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU CQ HEAT EXCHANGER
- Filing Date
- 2025-05-19
- Publication Date
- 2026-05-12
AI Technical Summary
In existing small steam generators, the vapor zone of the heat exchange tubes is prone to dry burning due to poor heat transfer performance, resulting in short service life, high maintenance rate, and insufficient steam dryness, which cannot meet the production process requirements of end users.
采用隔热部件将换热管圈分隔为主换热区和过热区，液态介质在燃烧区域内加热，汽态介质在高温烟气二次换热区加热，结合翅片、导流板和扰动内嵌管，优化烟气流动路径，提高传热效率和蒸汽干度。
It extends the service life of heat exchange tubes, reduces maintenance rate and cost, improves thermal energy utilization, meets the steam dryness requirements of end users, and realizes the miniaturization of equipment.
Smart Images
Figure CN224229971U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a boiler, and more particularly to a steam generator. Background Technology
[0002] A steam generator, also called a steam heat source machine (commonly known as a boiler), is a mechanical device that uses the thermal energy of fuel or other energy sources to heat water into hot water or steam. Traditional steam generators are generally horizontal or vertical. Their conventional working principle (taking water flowing from bottom to top within heat exchange tubes as an example) is as follows: the liquid in the heat exchange tubes is heated into a vapor state, and a steam drum is installed above the heat exchange tubes to deliver the vaporized water. Steam generators with a water volume of 30L or more are classified as special equipment and require inspection and registration. Steam generators with a water volume of less than 30L are not considered special equipment and do not require inspection, registration, or annual inspection.
[0003] For gas-fired steam generators that are exempt from inspection or reporting, or for conventional steam generators, in order to minimize their size, existing structures, taking vertical equipment as an example, generally employ a single ring of heat exchange tubes. The combustion zone is located inside these tubes, where high-temperature flue gas and thermal radiation heat the tubes, converting the liquid medium inside into a vapor state (the liquid medium enters from the bottom of the heat exchange tubes, while the vapor medium exits from the top). This structure presents the following problems:
[0004] Because the water inside the heat exchange tubes is gradually heated from a liquid state to a vapor state from bottom to top—that is, the heat exchange tubes are in the following order from bottom to top: liquid, vapor-liquid mixture, and vapor. While the heat transfer performance of the vapor state is poor, the temperature is basically the same throughout the combustion zone. The high temperature experienced by the heat exchange tubes in the liquid and vapor-liquid mixture regions can be directly transferred to the liquid water, heating it. For example, the heat exchange tubes in the lower liquid and vapor-liquid mixture regions experience temperatures of 800℃-1000℃, which can transfer heat to the liquid water, heating it to a vapor state. This prevents the heat exchange tubes from dry-burning and thus avoids damage. However, due to the poor heat transfer performance of the vapor state, the heat exchange tubes in the vapor state regions are essentially dry-burning, with temperatures potentially approaching or exceeding 500℃. To address this issue, conventional steam generators typically use heat-resistant alloy steel for the upper heat exchange tubes (in the vapor zone). This special alloy steel can withstand temperatures exceeding 500 degrees Celsius. However, in this structure, because this area is frequently subjected to dry burning, even the heat-resistant alloy steel is prone to damage, resulting in a relatively short service life, high maintenance rate, and high cost.
[0005] Lowering the temperature, while extending service life and reducing maintenance, can lead to insufficient steam dryness. Steam dryness is 100% if it contains no liquid water. Standard boiler steam dryness should be above 97%, and excellent boilers should reach above 99%. Insufficient steam dryness not only results in greater heat loss but also consumes more energy (e.g., gas-fired steam generators will consume more gas). Furthermore, excessive water content in the steam can fail to meet the production process requirements of some end-users. Summary of the Invention
[0006] The purpose of this invention is to provide a steam generator. By using this structure, the service life of the equipment can be effectively extended, the maintenance rate and cost can be reduced, and the performance of the equipment can be effectively guaranteed.
[0007] To achieve the above objectives, the technical solution adopted by this utility model is: a steam generator, comprising a furnace and multiple heat exchange tubes disposed within the furnace, wherein the multiple heat exchange tubes are arranged in a ring to form a heat exchange tube coil.
[0008] The heat exchange tubes are arranged vertically, with a gap between adjacent heat exchange tubes. The bottom of the heat exchange tube is a water inlet, and the top is a steam outlet.
[0009] A heat insulation component is provided in the middle of the inner side of the heat exchange tube coil, and the heat insulation component divides the heat exchange tube coil into a main heat exchange zone and a superheated zone.
[0010] The interior of the heat exchange tube ring below the insulation component is the main heat exchange zone, while the interior of the heat exchange tube ring above the insulation component is the superheated zone.
[0011] The main heat exchange zone is equipped with a burner.
[0012] In the above technical solution, the main heat exchange zone of the burner constitutes the combustion zone;
[0013] The high-temperature flue gas generated by the burner combustion exchanges heat with the heat exchange tubes in the main heat exchange zone and is then sent to the flue gas side area outside the heat exchange tube coil. From the flue gas side area outside the heat exchange tube coil, it enters the superheated zone inside the heat exchange tube coil and exchanges heat with the heat exchange tubes in the superheated zone.
[0014] In the above technical solution, liquid water enters the heat exchange tube from the inlet, is heated into a vapor state by the main heat exchange zone and the superheated zone, and is then sent out from the outlet.
[0015] And / or, the medium in the heat exchange tube is divided into a liquid phase region, a vapor-liquid two-phase mixing region, and a vapor state region from the water inlet to the steam outlet. The liquid phase region is located at the main heat exchange zone, the vapor state region is located at the superheated zone, and the vapor-liquid two-phase mixing region is located at the connection between the main heat exchange zone and the superheated zone.
[0016] In the above technical solution, multiple fins are spaced apart on the outer surface of each heat exchange tube, and the multiple fins are arranged along the extension direction of the heat exchange tube.
[0017] In the above technical solution, the fins are respectively provided with bends on opposite sides, the bends abut against the bends of the adjacent upper or lower fins, and the outside of the heat exchange tube between two adjacent fins forms a flue gas passage.
[0018] And / or, the side of the fin on each heat exchange tube is in contact with the side of the fin on the adjacent heat exchange tube, or the side of the fin on each heat exchange tube is disposed close to the side of the fin on the adjacent heat exchange tube.
[0019] In the above technical solution, one bent end of the fin in the main heat exchange zone is located on the outside of the heat exchange tube coil.
[0020] In the above technical solution, one bent end of the fin in the overheated zone is located on the outside of the heat exchange tube ring;
[0021] And / or, the other end of the fin bend in the superheated zone is located inside the heat exchange tube coil.
[0022] In the above technical solution, multiple outer guide plates are provided on the outer side of the heat exchange tube coil. The side of each outer guide plate is connected to or in contact with the side of the adjacent outer guide plate. Each outer guide plate is positioned directly opposite a heat exchange tube. The outer guide plate is connected to the fins or heat exchange tube.
[0023] In the above technical solution, the superheated zone is provided with multiple inner guide plates. The side of each inner guide plate is connected to or in contact with the side of the adjacent inner guide plate. Each inner guide plate is positioned opposite a heat exchange tube. The inner guide plate is connected to the fins or heat exchange tube.
[0024] In the above technical solution, the outer guide plate and the inner guide plate are respectively provided with through holes, and the through holes are arranged at intervals from bottom to top.
[0025] In the above technical solution, each heat exchange tube is further provided with a disturbance inner tube, the disturbance inner tube is disposed above the heat insulation component, and there is a gap between the disturbance inner tube and the inner wall of the heat exchange tube;
[0026] And / or, the disturbance inner tube is coaxially arranged with the heat exchange tube.
[0027] In the above technical solution, a water inlet header and a steam header are respectively provided at the bottom and top of the furnace. The water inlet at the bottom of the heat exchange tube is connected to the water inlet header, and the steam outlet at the top of the heat exchange tube is connected to the steam header.
[0028] In the above technical solution, the top of the steam header is provided with a steam vent, the steam header is provided with a steam-water separation plate, and the steam-water separation plate is disposed between the steam vent and the steam outlet.
[0029] And / or, the steam-water separation plate is a multi-stage steam-water separation plate.
[0030] In the above technical solution, a condensing heat exchanger is also provided on the side of the furnace, and the condensing heat exchanger is provided with multiple rows of spaced condensing side heat exchange tubes.
[0031] The superheated zone is provided with a first flue gas outlet, which is connected to the flue gas inlet of the condensing heat exchanger.
[0032] The condenser heat exchanger is equipped with a flue pipe, and the flue inlet and the flue pipe are respectively located on the upper and lower sides of the condenser-side heat exchange tube.
[0033] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art:
[0034] 1. In this utility model, a heat insulation component is directly installed inside the heat exchange tube coil, dividing the heat exchange tube coil into a combustion zone and a high-temperature flue gas secondary heat exchange zone. The liquid medium inside the heat exchange tube is located in the combustion zone, while the gaseous medium inside the heat exchange tube is located in the high-temperature flue gas secondary heat exchange zone. In this method, the combustion zone is used for heat exchange with the liquid medium, which has strong heat transfer performance. This allows the higher-temperature flue gas to be concentrated in the combustion zone to exchange heat with the liquid medium, while the lower-temperature flue gas is used to reheat the gaseous medium, effectively improving the steam dryness. At the same time, it can also prevent the heat exchange tube in the gaseous zone from being damaged by high temperature for a long time. Furthermore, the gas-liquid two-phase mixing zone is located at the heat insulation component, which can prevent dry burning in the gas-liquid two-phase mixing zone, effectively reducing the maintenance rate and extending the service life. It does not require the use of high-temperature resistant steel, which can reduce costs.
[0035] 2. This utility model can improve the utilization rate of thermal energy and reduce energy consumption and operating costs;
[0036] 3. The present invention also includes fins to improve the heat exchange effect. The fins are also bent to form a flue gas channel, so that the high-temperature flue gas can contact the back of the combustion zone as much as possible, so that the heat exchange tube is uniformly heated in all positions, reducing the heat exchange intensity difference, reducing the temperature difference of the tube wall, making the heat exchange tube uniform in the circumferential direction, and extending the service life of the heat exchange tube.
[0037] 4. This utility model also includes inner and outer guide plates, which can control the flow path of high-temperature flue gas, ensuring and controlling the heat exchange effect;
[0038] 5. In this utility model, a disturbance embedded tube is also provided inside the heat exchange tube, which can improve the steam dryness and the micro-superheat state. Attached Figure Description
[0039] Figure 1 This is a schematic diagram of the structure in Embodiment 1 of this utility model;
[0040] Figure 2 This is a three-dimensional structural diagram of Embodiment 1 of this utility model (the arrows indicate the flow path and direction of flue gas from the superheated zone toward the condenser heat exchanger);
[0041] Figure 3 yes Figure 1 A cross-sectional view of the middle AA (arrows indicate the flow path and direction of the flue gas);
[0042] Figure 4 yes Figure 1 Schematic diagram of the cross-sectional structure of BB;
[0043] Figure 5 This is a partial enlarged view of the flue gas flow path around the heat exchange tube in the main heat exchange zone of Embodiment 1 of this utility model (the arrows indicate the flue gas flow path and direction);
[0044] Figure 6 This is a cross-sectional view of the heat insulation component and a single heat exchange tube in Embodiment 1 of this utility model (the heat exchange tube contains a medium);
[0045] Figure 7 This is a partial enlarged view of the connection between the heat exchange tube and the steam header in Embodiment 1 of this utility model.
[0046] The components are as follows: 1. Furnace; 2. Heat exchange tubes; 3. Heat exchange tube coils; 4. Insulation components; 5. Main heat exchange zone; 6. Superheated zone; 7. First flue gas outlet; 8. Water inlet; 9. Steam outlet; 10. Liquid phase zone; 11. Vapor-liquid two-phase mixing zone; 12. Vapor zone; 13. Fins; 14. Bending; 15. Flue gas passage; 16. Outer guide plate; 17. Through hole; 18. Inner guide plate; 19. Disturbance embedded tube; 20. Water inlet header; 21. Steam header; 22. Steam outlet; 23. Steam-water separator plate; 24. Primary steam-water separator plate; 25. Secondary steam-water separator plate; 26. Condensing heat exchanger; 27. Flue gas pipe; 28. Backfire area of the main heat exchange zone; 29. Burner. Detailed Implementation
[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments:
[0048] Example 1: See Figure 1-7 As shown, a steam generator includes a furnace 1 and multiple heat exchange tubes 2 disposed within the furnace 1. The multiple heat exchange tubes 2 are arranged in a ring to form a heat exchange tube coil 3. The heat exchange tubes are arranged vertically, with a gap between adjacent heat exchange tubes 2. The bottom of each heat exchange tube 2 is a water inlet 8, and the top of each heat exchange tube 2 is a steam outlet 9. A heat insulation component 4 is provided on the inner side of the heat exchange tube coil 3, which divides the heat exchange tube coil 3 into a main heat exchange zone 5 and a superheated zone 6. The main heat exchange zone 5 is a combustion zone, and the superheated zone 6 is a secondary heat exchange zone for high-temperature flue gas. The first exhaust port 7 is located in the superheated zone 6, away from the heat insulation component 4. The main heat exchange zone is located inside the heat exchange tube coil below the heat insulation component, and the superheated zone is located inside the heat exchange tube coil above the heat insulation component. A burner 29 is located in the main heat exchange zone.
[0049] The main heat exchange zone, where the burner is installed, constitutes the combustion zone;
[0050] The high-temperature flue gas generated by the burner combustion exchanges heat with the heat exchange tubes in the main heat exchange zone and is then sent to the flue-side region outside the heat exchange tube coil (inside the furnace outside the heat exchange tube coil). From the flue-side region outside the heat exchange tube coil (inside the furnace outside the heat exchange tube coil), it enters the superheated zone inside the heat exchange tube coil and exchanges heat with the heat exchange tubes in the superheated zone. Therefore, the superheated zone constitutes a secondary heat exchange zone for the high-temperature flue gas.
[0051] The liquid medium enters the heat exchange tube 2 through the inlet 8, is heated into a vapor state through the main heat exchange zone 5 and the superheated zone 6, and is then sent out from the outlet 9.
[0052] The medium in the heat exchange tube 2 consists of a liquid phase zone 10, a vapor-liquid two-phase mixing zone 11, and a vapor zone 12 between the water inlet 8 and the steam outlet 9. The liquid phase zone 10 is located on the side of the main heat exchange zone 5, the vapor zone 12 is located on the side of the superheated zone 6, and the vapor-liquid two-phase mixing zone 11 is located at the connection between the main heat exchange zone 5 and the superheated zone 6. The two ends of the vapor-liquid two-phase mixing zone 11 are respectively located on the side of the main heat exchange zone 5 and the side of the superheated zone 6.
[0053] In this embodiment, the heat exchange tube coil forms a ring structure, and a heat insulation component is disposed inside the ring structure. The outer surface of the heat insulation component abuts against the inner surface of the heat exchange tube coil, thereby dividing the ring structure into two chambers: a main heat exchange zone and a superheated zone. The main heat exchange zone is the combustion zone, where a burner 29 can be installed. The superheated zone does not contain a burner. The high-temperature flue gas and thermal radiation generated in the combustion zone are directly transferred to the heat exchange tube coil on its outer side, i.e., to the heat exchange tubes located on the main heat exchange zone side. Since the heat exchange tubes in the main heat exchange zone are mainly in the liquid phase, i.e., mainly contain liquid water, the bottom of the heat exchange tubes is the water inlet. Liquid water enters the heat exchange tubes through the water inlet and exchanges heat with the heat exchange tubes through the thermal radiation of the combustion zone and the high-temperature flue gas, causing the liquid water to gradually vaporize. The liquid surface in the liquid phase zone is located near the bottom surface of the heat insulation component. In this embodiment, the heat insulation component is made of refractory bricks or other heat insulation materials. When water boils and vaporizes, it generates a large number of bubbles, which rise and pass through the liquid surface. That is, the heat insulation component (the connection between the main heat exchange zone and the superheated zone) forms a vapor-liquid two-phase mixing zone. The heat exchange tubes in this zone contain part liquid water and part water vapor. Taking the high-temperature flue gas temperature in the combustion zone as 800℃-1000℃ as an example, after the high-temperature flue gas exchanges heat with the heat exchange tubes in the main heat exchange zone, the high-temperature flue gas in the main heat exchange zone will be sent out from the gap between adjacent heat exchange tubes to the outside of the heat exchange tube coil (the backfire area 28 of the main heat exchange zone). The temperature of the high-temperature flue gas sent out to the outside of the heat exchange tube coil is about 300℃-350℃, and then it mixes with the superheated... In the heat exchange tube coil, the outer surface of the heat exchange tubes in the superheated zone contacts the outer surface for heat exchange. Then, passing through the gap between adjacent heat exchange tubes in the superheated zone, the gas enters the superheated zone and contacts the outer surface of the inner surface of the heat exchange tube coil in the superheated zone for heat exchange. At this point, the high-temperature flue gas inside the superheated zone is approximately 180–200°C, while the steam temperature in the vapor-liquid two-phase mixing zone and the vaporous zone is approximately 160–180°C. This allows for further heat exchange between the high-temperature flue gas in the superheated zone and the steam and water mist inside the heat exchange tubes, thereby increasing the steam dryness. Simultaneously, the contact temperature between the high-temperature flue gas and the heat exchange tubes in the vaporous zone will not exceed 400°C, preventing overheating of the heat exchange tubes, effectively preventing damage, reducing maintenance rates, and extending service life. Furthermore, the heat exchange tubes are made of ordinary boiler steel, eliminating the need for more expensive high-temperature resistant materials, thus effectively reducing costs.
[0054] Furthermore, in this embodiment, by setting up heat insulation components, the high-temperature zone can be basically controlled in the liquid phase zone, and heat exchange with liquid water can be maximized. Since liquid water has good heat transfer performance, its heat exchange effect is good, which effectively improves the heat exchange effect, saves energy consumption, and reduces the cost of use.
[0055] Furthermore, when the heat exchange tube is subjected to high temperatures, liquid water will adhere to the tube wall inside the heat exchange tube in the vapor-liquid two-phase mixing zone (there will be liquid water on the tube wall for a certain distance above the liquid surface, and it will be in contact with the tube wall; there will be no liquid water near the tube axis, or only some liquid water carried out by the vapor bubbles, the middle part of which is mainly water vapor with a not particularly high dryness). The heat transfer performance of liquid water is stronger, and the heat exchange effect is better, which can effectively prevent the heat exchange tube on the main heat exchange zone side of the insulation component from dry burning, prevent damage to the heat exchange tube at the insulation component, and effectively ensure its service life.
[0056] Furthermore, to improve heat exchange efficiency, see [reference needed]. Figure 5 As shown, each heat exchange tube 2 has multiple fins 13 spaced apart on its outer surface, and these fins 13 are arranged along the extension direction of the heat exchange tube 2. In this configuration, the heat exchange tube is a finned tube, which increases the contact area between the heat exchange tube and the high-temperature flue gas, thereby improving the heat exchange effect. Of course, since the temperature in the main heat exchange zone is high, finned tubes can be omitted, and a smooth tube (without fins, and a smooth surface) can be used.
[0057] See Figure 5 As shown, the fins 13 are provided with bends 14 on opposite sides. The bends 14 abut against the bends 14 of the adjacent upper or lower fins 13, and the outside of the heat exchange tube 2 between two adjacent fins 13 forms a flue gas passage 15.
[0058] In this embodiment, all the fins are bent downwards on both sides (or they can all be bent upwards). If no bending is set, the fins will increase the contact area with the flue gas, thus improving the heat exchange effect. At the same time, when the high-temperature flue gas in the main heat exchange zone passes through the heat exchange tube and is sent out of the heat exchange tube coil, the flue gas will contact the outer surface of the inner end of the heat exchange tube (the inner side of the heat exchange tube coil, i.e., the combustion zone side), and the contact area with the outer end of the heat exchange tube (the outer side of the heat exchange tube coil, i.e., the unfired area side of the main heat exchange zone) will be less. Since the heat exchange tube on the combustion zone side receives better heat radiation and heat convection heat exchange and has a higher heat exchange intensity, while the heat radiation and heat convection heat exchange in the unfired area of the main heat exchange zone will be worse, resulting in a larger temperature difference between the inner and outer ends of the heat exchange tube, which in turn affects the service life of the heat exchange tube. Therefore, in this embodiment, the bending setting is used to adjust the flow path of the high-temperature flue gas through the heat exchange tube, to increase the contact area and / or time between the high-temperature flue gas and the backfire area of the main heat exchange zone of the heat exchange tube, to make the heat exchange tube more uniform in the circumferential direction as much as possible, to reduce the temperature difference between the inner and outer ends of the heat exchange tube, and to extend the service life of the heat exchange tube.
[0059] Furthermore, to ensure effective heat exchange and maximize the contact area and heat exchange efficiency between the high-temperature flue gas and the fins and heat exchange tubes, the side of the fins on each heat exchange tube is in contact with the side of the fins on the adjacent heat exchange tube, or the side of the fins on each heat exchange tube is positioned close to the side of the fins on the adjacent heat exchange tube. In this configuration, the high-temperature flue gas exits from the main heat exchange zone to the outside of the heat exchange tube coil and enters the superheated zone from the outside of the heat exchange tube coil. The high-temperature flue gas can only, or mostly, pass through the flue gas channel and flows along the path of the flue gas channel, minimizing its escape from the gap between the fins of adjacent heat exchange tubes. This ensures sufficient contact between the high-temperature flue gas and the fins and heat exchange tubes, effectively improving the heat exchange efficiency, fully utilizing thermal energy, saving energy consumption, and reducing operating costs.
[0060] See Figure 5As shown, to precisely control the flow direction of the flue gas, one bend of the fin 13 in the main heat exchange zone 5 is located outside the heat exchange tube coil 3. Two bends are symmetrically arranged on both sides of the fin, with one bend located between adjacent heat exchange tubes and the other end outside the heat exchange tube coil. In this configuration, since the main heat exchange zone is a combustion zone, its heat radiation is stronger and the temperature of the high-temperature flue gas is higher, resulting in better heat exchange. Therefore, one end of the fin in the main heat exchange zone is located outside the heat exchange tube coil, meaning the bend of the fin at this location is at the outer end of the heat exchange tube, while the other end is not located within the main heat exchange zone. This bend is primarily located in the unfired area of the main heat exchange zone. The two bends form a flue gas outlet, which is preferably smaller than the diameter or radius of the heat exchange tube, and this outlet is directly opposite the axis of the heat exchange tube coil. The fin side within the main heat exchange zone is not bendable, thus ensuring the main heat exchange zone... The high-temperature flue gas inside the tubes fully contacts and exchanges heat with the inner side of the heat exchange tubes. The flue gas channel in the main heat exchange zone is an arc-shaped channel. The flue gas flows outward from both sides of the heat exchange tubes between the upper and lower adjacent fins. Due to the bends, the flow path of the flue gas is changed. It flows around the heat exchange tubes, towards the outer ends of the two bends, and flows out from the flue gas outlet. This allows the flue gas to flow around the outer surface of the heat exchange tubes and contact the back-fired side of the heat exchange tubes. This enhances the convective heat exchange between the high-temperature flue gas and the heat exchange tubes in the back-fired area of the main heat exchange zone, thereby reducing the temperature difference of the tube wall, improving the uniformity of heat exchange in the circumferential direction of the heat exchange tubes, and extending the service life of the heat exchange tubes.
[0061] Similarly, one bent end of the fin in the superheated zone is located inside the heat exchange tube coil. Two bends are symmetrically arranged on both sides of the middle of the fin, with one bend positioned between adjacent heat exchange tubes and the other end inside the heat exchange tube coil, within the superheated zone. That is, most of the bends are located within the superheated zone. Since the temperature of the high-temperature flue gas outside the heat exchange tube coil exceeds that inside the superheated zone, this also enhances the heat exchange effect of the heat exchange tubes in the superheated zone, improves the uniformity of heat exchange in the circumferential direction of the heat exchange tubes in the superheated zone, and extends the service life of the heat exchange tubes.
[0062] Of course, as another embodiment, all the aforementioned bends are only set on the outside of the heat exchange tube coil (which can reduce processing difficulty and production costs), that is, all bends are located in the backfire area of the main heat exchange zone. This is because the temperature of the high-temperature flue gas in the superheated zone and the backfire area of the main heat exchange zone is not very high, and the temperature difference is only about 100 degrees Celsius (the temperature difference between the main heat exchange zone and the backfire area of the main heat exchange zone may be close to 500℃~700℃, which is a particularly large temperature difference). The heat exchange is also relatively uniform and will not affect the service life of the heat exchange tube.
[0063] In another preferred embodiment, one end of the fin bend in the superheated zone is located on the outer side of the heat exchange tube coil; the other end of the fin bend in the superheated zone is located on the inner side of the heat exchange tube coil. That is, the bends in the superheated zone are symmetrically arranged on opposite sides of the heat exchange tube, with one end of the bend on the outer side of the heat exchange tube coil and the other end on the inner side. This ensures that the inlet and outlet dimensions of the flue gas passage in the superheated zone are smaller than the diameter or radius of the heat exchange tube. As a result, when the flue gas passes through the flue gas passage, the high-temperature flue gas first contacts and exchanges heat with the outer end of the heat exchange tube, then contacts the inner end of the heat exchange tube, and is then discharged from the inner end of the heat exchange tube. This ensures that the high-temperature flue gas fully contacts the circumferential direction of the heat exchange tube, improving the heat exchange effect.
[0064] See Figure 5 As shown, the heat exchange tube coil 3 is further provided with multiple outer guide plates 16. The side portion of each outer guide plate 16 is connected to or in contact with the side portion of the adjacent outer guide plate 16. Each outer guide plate 16 is positioned directly opposite a heat exchange tube 2. The outer guide plate 16 is connected to the fins 13 or the heat exchange tube 2. The outer guide plate 16 is provided with through holes 17.
[0065] In this invention, the outer guide plate has two installation structures: the outer guide plate is connected to the heat exchange tube, or the outer guide plate is connected to the fins. If fins are not installed, the outer guide vanes are directly connected to the heat exchange tubes. Since the outer guide vanes are interconnected, they form a ring structure, which is equivalent to setting an annular cover outside the heat exchange tube ring (the outer guide vanes can only contact the heat exchange tubes at their edges or only at their edges, or they can contact the heat exchange tubes through support rods, as long as it does not affect the flue gas being sent out from the main heat exchange zone and then into the superheated zone). Furthermore, the outer guide vanes are set close to the heat exchange tube ring, so that the high-temperature flue gas in the main heat exchange zone is restricted by the annular cover after it comes out of the heat exchange tube ring, thereby allowing the high-temperature flue gas to contact as many parts of the heat exchange tube as possible, improving the heat exchange effect. At the same time, in order to allow the heat exchange flue gas to be smoothly sent out of the outer guide vanes and then into the superheated zone, through holes are also provided. This allows the high-temperature flue gas to be sent out of the outer guide vanes through the through holes and then sent into the superheated zone from the outer guide vanes. More preferably, the through holes are set directly opposite the axis of the heat exchange tube coil. There are multiple through holes, which are arranged at intervals along the length of the outer guide plate. In this way, the high-temperature flue gas delivered from the main heat exchange zone will be blocked by the outer guide plate and will fully contact the back-fire area of the main heat exchange zone of the heat exchange tube for heat exchange before being delivered out through the through holes. This not only ensures the heat exchange effect but also makes the temperature difference of the tube wall small and the service life long.
[0066] If fins are used, it's difficult to ensure all fins on the heat exchange tubes are in contact with adjacent fins during assembly, resulting in gaps between them. This allows some high-temperature flue gas to flow between the fins of adjacent tubes, affecting heat exchange efficiency. Therefore, an outer guide plate is used. The inner wall of the outer guide plate connects to the fins on each heat exchange tube, effectively covering a cylindrical structure composed of multiple fins with a ring-shaped outer guide plate. Adjacent outer guide plates are in contact or connected, preferably using an overlapping or interlocking method, so that the ring structure formed by multiple outer guide plates covers the outside of the heat exchange tube coil. The through-holes on each outer guide plate are positioned between two bends, allowing high-temperature flue gas to flow quickly and directly out through the through-holes after exiting the flue gas channel. Alternatively, high-temperature flue gas from the backfire area of the main heat exchange zone can flow into the flue gas channel through the through-holes and then be sent into the superheated zone, improving heat exchange efficiency. Among them, through holes can be strip-shaped through holes.
[0067] See Figure 3 As shown, the superheated zone 6 is provided with multiple inner guide plates 18. The side portion of each inner guide plate 18 is connected to or in contact with the side portion of the adjacent inner guide plate 18. Each inner guide plate 18 is positioned directly opposite a heat exchange tube 2. The inner guide plate 18 is connected to the fins 13 or the heat exchange tube 2 (if the heat exchange tube is a bare tube, the inner guide plate may only have its edge portion in contact with the heat exchange tube, or it may be in contact with the heat exchange tube through a support rod, as long as it does not affect the entry of flue gas from the outside of the superheated zone into the superheated zone). The inner guide plate is provided with through holes, which are strip-shaped through holes. The installation structure of the inner guide plate is similar to or the same as that of the outer guide plate. It can be connected to the fins or directly to the heat exchange tube. In this way, the distribution of the flue gas flow field can be optimized according to the heat transfer intensity required by different regions (liquid phase region, vapor-liquid two-phase mixing region and vapor state region). For the liquid phase region, the heat transfer intensity of the flue gas can be enhanced. For the vapor-liquid two-phase mixing region or transition region (the connection between the vapor-liquid two-phase mixing region and the liquid phase region is the transition region, and the connection between the vapor-liquid two-phase mixing region and the vapor state region is also the transition region), the heat transfer intensity of the flue gas can be reduced or increased. Thus, the convective heat transfer of the flue gas can be adjusted according to the vapor and liquid positions in the heat exchange tube, avoiding excessive heat transfer intensity in local areas and improving the service life of the heat exchange tube.
[0068] In this design, the through-hole size in the vapor zone is larger than that in the liquid zone, and the through-hole size in the liquid zone is larger than that in the vapor-liquid two-phase mixing zone. In this configuration, since the temperature of the high-temperature flue gas entering the superheated zone is not inherently very high, and the required temperature in the vapor zone is not particularly high, and the heat transfer performance of the vapor phase is poor, the through-hole size in this zone is the largest, and the required heat exchange effect can be minimized. The flue gas temperature in the liquid zone is inherently high, and the heat transfer performance of the liquid phase is the best, so its heat exchange effect can be set higher; therefore, the through-hole size in this zone can be set slightly smaller. The through-hole size in the vapor-liquid two-phase mixing zone is the smallest. Because this zone contains both liquid and vapor states, but is not purely liquid, its heat transfer performance is worse than that of a pure liquid state, but better than that of a vapor state. Since part of the vapor-liquid two-phase mixing zone is located within the main heat exchange zone, the high-temperature flue gas temperature in this portion of the vapor-liquid two-phase mixing zone is the same as the high-temperature flue gas temperature in the liquid phase zone. However, the heat transfer effect in the vapor-liquid two-phase mixing zone is worse than that in the liquid phase zone. Therefore, to protect the heat exchange tubes in the vapor-liquid two-phase mixing zone and prevent damage, the through-hole size in the vapor-liquid two-phase mixing zone is set to the minimum. This reduces the heat transfer intensity and thus protects the heat exchange tubes. (Because the high-temperature flue gas temperature is the same in the liquid phase zone and part of the vapor-liquid two-phase mixing zone, the through-hole size in the vapor-liquid two-phase mixing zone is smaller. Therefore, the high-temperature flue gas flow rate in the vapor-liquid two-phase mixing zone is smaller, thereby reducing the heat transfer intensity of the heat exchange tubes in the vapor-liquid two-phase mixing zone and protecting them.) Of course, the through-hole size can also be the same at all locations.
[0069] See Figure 3 , 6 As shown, each heat exchange tube 2 is further provided with a disturbance inner tube 19. The disturbance inner tube is disposed above the heat insulation component. Furthermore, the disturbance inner tube 19 is disposed in the vapor zone 12, and there is a gap between the outer surface of the disturbance inner tube 19 and the inner surface of the heat exchange tube 2 (multiple rods can be provided on the outer surface of the disturbance inner tube to connect with the inner wall of the heat exchange tube, or the top of the disturbance inner tube can be connected with the steam header, thereby realizing the fixation of the disturbance inner tube, or other fixed placement).
[0070] The disturbance embedded tube 19 is coaxially arranged with the heat exchange tube 2.
[0071] Since the steam in the vapor zone mainly undergoes convective heat transfer, there is no need to consider the temperature difference between the inside and outside of the heat exchange tube. Therefore, by setting up a disturbance embedded tube in the vapor zone, the volume of the vapor zone can be reduced. At the same time, it allows the steam inside to contact the inner wall of the heat exchange tube as much as possible, thereby improving the convective heat transfer effect, thus increasing the steam dryness or raising it to a slightly superheated state.
[0072] See Figure 3 , 6As shown, the furnace 1 is provided with a water inlet header 20 and a steam header 21 at the bottom and top, respectively. The water inlet 8 at the bottom of the heat exchange tube 2 is connected to the water inlet header 20, and the steam outlet 9 at the top of the heat exchange tube 2 is connected to the steam header 21.
[0073] In this method, external water is fed into the inlet manifold, which simultaneously supplies water to all heat exchange tubes. This ensures that the liquid level in all heat exchange tubes is consistent or nearly consistent, allowing for precise control of the flow rate and thus ensuring accurate steam dryness. The steam emitted from all the heat exchange tubes is collected and sent into the steam manifold, where it is then discharged together via a dedicated pipeline.
[0074] The steam header 21 is provided with a steam vent 22 at the top, and a steam-water separator 23 is provided inside the steam header 21. The steam-water separator 23 is located between the steam vent 22 and the steam outlet 9.
[0075] The steam-water separator plate is a multi-stage steam-water separator plate.
[0076] In this embodiment, the steam-water separation plate is a two-stage steam-water separation plate, which includes a first-stage steam-water separation plate 24 and a second-stage steam-water separation plate 25. The first-stage steam-water separation plate adopts a mesh plate structure, which can separate liquid water in the steam. The second-stage steam-water separation plate adopts a steam-water baffle structure, which uses the centrifugal force of the steam flow to further separate water in the steam and improve the steam dryness.
[0077] See Figure 1 , 2 As shown in Figure 4, a condensing heat exchanger 26 is also provided on the side of the furnace 1, and the condensing heat exchanger 26 is provided with multiple rows of condensing side heat exchange tubes arranged at intervals.
[0078] The superheated zone 1 is provided with a first flue gas outlet 7. The first flue gas outlet and the heat insulation component are respectively located at both ends of the superheated zone. One end of the first flue gas outlet 7 is connected to the flue gas inlet of the condenser heat exchanger 26, and the other end of the first flue gas outlet 7 is connected to the superheated zone 6. In this embodiment, a hole can be provided in the middle of the steam header, which constitutes the first flue gas outlet. Its bottom is connected to the superheated zone, and its top is connected to the condenser heat exchanger. The medium-temperature flue gas entering the superheated zone (after heat exchange with the high-temperature flue gas in the superheated zone, the temperature drops to medium-temperature flue gas) is sent out from the first flue gas outlet and enters the condenser heat exchanger to exchange heat with the condenser-side heat exchange tubes in the condenser heat exchanger.
[0079] The condenser heat exchanger 26 is provided with a flue pipe 27. The flue inlet and the flue pipe 27 of the condenser heat exchanger 26 are respectively located on both sides of the condenser heat exchange tube (the liquid inlet and the flue pipe are respectively located on the upper and lower sides of the condenser heat exchange tube, or on the left and right sides, or on the front and rear sides).
[0080] In this embodiment, the flue gas inlet of the condensing heat exchanger is located at its top, and the flue gas pipe is located on its lower side. The flue gas inlet is connected to the first flue gas outlet through a pipe. The condensing-side heat exchange tube is designed with multi-pass water circulation. The inlet of the condensing-side heat exchange tube is connected to an external water source, and the outlet of the condensing-side heat exchange tube can be connected to an external pipe alone, or it can be connected to the inlet of the water inlet manifold. Preferably, it is connected to the inlet of the water inlet manifold. After the medium-temperature flue gas passes through the condensing-side heat exchange tube, it is discharged from the flue gas pipe. This allows the medium-temperature flue gas, which is not particularly high in temperature, to heat or preheat the water in the condensing-side heat exchange tube. The heated water is then sent into the water inlet manifold and subsequently into the heat exchange tube, where it can be heated and vaporized more quickly, thereby saving energy, reducing costs, and improving energy utilization.
[0081] Meanwhile, the use of heat insulation components in this invention allows for a smaller steam generator, making the equipment more compact.
[0082] In the description of this utility model, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0083] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. For instance, the two components can be mechanically connected by abutting or contacting each other; they can also be directly hung or connected by an intermediate medium; or they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
Claims
1. A steam generator, comprising a furnace and a plurality of heat exchange tubes disposed within the furnace, wherein the plurality of heat exchange tubes are arranged in a ring to form a heat exchange tube coil, characterized in that: The heat exchange tubes are arranged vertically, with a gap between adjacent heat exchange tubes. The bottom of the heat exchange tube is a water inlet, and the top is a steam outlet. A heat insulation component is provided in the middle of the inner side of the heat exchange tube coil, and the heat insulation component divides the heat exchange tube coil into a main heat exchange zone and a superheated zone. The heat exchange tube ring below the insulation component is the main heat exchange zone, and the heat exchange tube ring above the insulation component is the superheated zone. The main heat exchange zone is equipped with a burner.
2. The steam generator according to claim 1, characterized in that: The main heat exchange zone, where the burner is installed, constitutes the combustion zone; The high-temperature flue gas generated by the burner combustion exchanges heat with the heat exchange tubes in the main heat exchange zone and is then sent to the flue gas side area outside the heat exchange tube coil. From the flue gas side area outside the heat exchange tube coil, it enters the superheated zone inside the heat exchange tube coil and exchanges heat with the heat exchange tubes in the superheated zone.
3. The steam generator according to claim 1 or 2, characterized in that: Liquid water enters the heat exchange tube from the inlet, is heated into a vapor state by the main heat exchange zone and the superheated zone, and is then sent out from the outlet. And / or, the medium in the heat exchange tube is divided into a liquid phase region, a vapor-liquid two-phase mixing region, and a vapor state region from the water inlet to the steam outlet. The liquid phase region is located at the main heat exchange zone, the vapor state region is located at the superheated zone, and the vapor-liquid two-phase mixing region is located at the connection between the main heat exchange zone and the superheated zone.
4. The steam generator according to claim 1, characterized in that: Each heat exchange tube has multiple fins spaced apart on its outer surface, and the multiple fins are arranged along the extension direction of the heat exchange tube.
5. The steam generator according to claim 4, characterized in that: The fins are respectively provided with bends on opposite sides, and the bends abut against the bends of the adjacent upper or lower fins, so that the outside of the heat exchange tube between two adjacent fins forms a flue gas passage. And / or, the side of the fin on each heat exchange tube is in contact with the side of the fin on the adjacent heat exchange tube, or the side of the fin on each heat exchange tube is disposed close to the side of the fin on the adjacent heat exchange tube.
6. The steam generator according to claim 5, characterized in that: One bent end of the fin in the main heat exchange zone is located on the outside of the heat exchange tube coil.
7. The steam generator according to claim 5, characterized in that: One bent end of the fin in the superheated zone is located on the outside of the heat exchange tube coil; And / or, the other end of the fin bend in the superheated zone is located inside the heat exchange tube coil.
8. The steam generator according to claim 4, characterized in that: The heat exchange tube coil is also provided with multiple outer guide plates. The side of each outer guide plate is connected to or in contact with the side of the adjacent outer guide plate. Each outer guide plate is positioned directly opposite a heat exchange tube. The outer guide plate is connected to the fins or heat exchange tube.
9. The steam generator according to claim 8, characterized in that: The superheated zone is provided with multiple inner guide plates. The side of each inner guide plate is connected to or in contact with the side of the adjacent inner guide plate. Each inner guide plate is positioned opposite a heat exchange tube. The inner guide plate is connected to the fins or heat exchange tube.
10. The steam generator according to claim 9, characterized in that: The outer and inner guide plates are respectively provided with through holes, which are arranged at intervals from bottom to top.
11. The steam generator according to claim 1, characterized in that: Each heat exchange tube is further provided with a disturbance inner tube, which is disposed above the heat insulation component and has a gap between the disturbance inner tube and the inner wall of the heat exchange tube. And / or, the disturbance inner tube is coaxially arranged with the heat exchange tube.
12. The steam generator according to claim 1, characterized in that: The furnace is provided with a water inlet header and a steam header at the bottom and top, respectively. The water inlet at the bottom of the heat exchange tube is connected to the water inlet header, and the steam outlet at the top of the heat exchange tube is connected to the steam header.
13. The steam generator according to claim 12, characterized in that: The top of the steam header is provided with a steam vent, and the steam header is provided with a steam-water separator plate, which is located between the steam vent and the steam outlet. And / or, the steam-water separation plate is a multi-stage steam-water separation plate.
14. The steam generator according to claim 1 or 2, characterized in that: A condensing heat exchanger is also provided on the side of the furnace, and the condensing heat exchanger is provided with multiple rows of spaced condensing side heat exchange tubes. The superheated zone is provided with a first flue gas outlet, which is connected to the flue gas inlet of the condensing heat exchanger. The condenser heat exchanger is equipped with a flue pipe, and the flue inlet and the flue pipe are respectively located on the upper and lower sides of the condenser-side heat exchange tube.