Condensation shell-and-tube heat exchanger

Abstract

The invention discloses a condensation shell-and-tube heat exchanger. A condensation heat exchange module of the heat exchanger is installed in a box body, the condensation heat exchange module comprises an enhanced heat exchange tube array and a flow guide assembly, the enhanced heat exchange tube array is located between cellular tube plates of the flow guide assembly, and a spiral turbulent flow structure is arranged in the enhanced heat exchange tube array. Flue gas spoilers are also obliquely arranged on the cellular tube plate and are distributed in the enhanced heat exchange tube array in a staggered manner to form a continuous wave-shaped flow channel and a periodic contraction-expansion flow channel; a water collector below the box body collects and discharges liquefied flue gas through a gradually-shrunk condensate water collecting cavity. A laminar flow boundary layer is broken through a spiral-fin composite heat transfer structure, and the heat exchange uniformity is improved in combination with a multi-pass turn-back water flow channel. Through the synergistic effect of the V-shaped turbulent flow and the gradually-shrinking flow channel, the flue gas temperature is obviously reduced. The double-protection system effectively blocks the corrosion of acidic condensate water, and the modular design reduces the manufacturing cost while cancelling an additional protection cavity.

Description

Technical Field

[0001] This invention relates to a heat exchanger, specifically to a condenser shell-and-tube heat exchanger, within the field of water heater technology. Background Technology

[0002] Traditional gas water heaters, under rated operating conditions, emit flue gas at temperatures reaching 180±10℃, containing approximately 15% latent heat of water vapor and significant amounts of CO and NOx pollutants. This results in a double waste of resources: firstly, 15%-20% of the heat energy is lost with the flue gas; secondly, the surface temperature of the unit exceeds the safety threshold (>60℃) due to heat conduction, posing a significant risk of scalding. In contrast, condensing gas water heaters, by adding a condensing heat exchanger, achieve cascaded recovery of waste heat from the flue gas, reducing the exhaust temperature to below 60℃ and controlling the unit temperature rise to within 15K, while simultaneously increasing thermal efficiency to over 96%. Their core advantage lies in preheating cold water using a non-combustion heat source (i.e., waste flue gas), effectively recovering the 1.6kg latent heat of water vapor generated per cubic meter of natural gas combustion, achieving an energy saving rate increase of 15%-20%.

[0003] However, existing condensing technology still faces structural bottlenecks: First, the mainstream top-mounted and split-type layouts result in a 30%-45% increase in equipment volume, leading to poor installation adaptability (e.g., limited bathroom space); second, when medium-temperature flue gas (160-200℃) flows through the condensing heat exchange surface, the water vapor it carries transforms into liquid condensate during the latent heat release process. This process interacts with CO2 and NO in the flue gas. x The combination of the dissolving effect of acidic components creates an acidic corrosive medium with a pH value < 4.5. This acidic condensate causes corrosion of copper components (rate > 0.15 mm / year), requiring an additional neutralization system and drainage pipes, resulting in a decreased user experience. Thirdly, some condensing gas water heaters are equipped with atomizing devices to atomize the condensate and discharge the water mist outdoors along with the flue gas. However, this atomization method is inefficient and has poor drainage performance.

[0004] Currently, developing compact and efficient shell-and-tube heat exchangers has become an inevitable choice for technological iteration in the industry: under the premise of ensuring a latent heat recovery rate of ≥95%, the flue gas resistance must be controlled at ΔP<120Pa through flow channel optimization, and a self-neutralizing condensate treatment system (pH value adjusted to 6.5-7.5) must be integrated to break through the dilemma of energy efficiency improvement and structural reliability in existing technologies. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a condenser shell-and-tube heat exchanger. This invention can solve the problem of preventing corrosion from acidic condensate while recovering latent heat in the heat exchanger.

[0006] The technical solution adopted in this invention is:

[0007] The condenser shell-and-tube heat exchanger of the present invention includes:

[0008] The housing is used for the flow of flue gas and water during heat exchange.

[0009] The condensing heat exchange module installed inside the housing includes an enhanced heat exchange tube array and a flow guiding component. The flow guiding component includes two partitioned tube sheets for flow guidance and several spiral turbulence structures. The enhanced heat exchange tube array is located between the two partitioned tube sheets, and each spiral turbulence structure is set inside the enhanced heat exchange tube array. Several V-shaped flue gas turbulence plates are also inclinedly arranged on the two partitioned tube sheets and are staggered between the enhanced heat exchange tube array. Each V-shaped flue gas turbulence plate forms a continuous wave-shaped flow channel, and the water flow is multi-passed back and forth through the partitioned tube sheets. The heating water of the condensing heat exchange module is guided by the flow guiding components on both sides of the housing and discharged from the other side of the housing near the bottom.

[0010] The water collector is installed at the bottom of the housing and directly below the condensing heat exchange module. It is sealed and connected to the housing and collects and discharges the liquefied flue gas through a gradually narrowing condensate collection chamber.

[0011] The condenser shell-and-tube heat exchanger is made entirely of stainless steel or aluminum alloy and uses a modular cubic frame. The housing serves as the core heat exchange chamber and has a cubic structure with reinforcing ribs at the corners. Key welds are passivated.

[0012] The upper and lower ends of the housing are respectively sealed with a flue gas discharge end and a flue gas inlet end. The flue gas discharge end consists of a flue gas outlet interface and a detachable top cover, which are integrally formed. The cross-section of the top cover decreases linearly from bottom to top along the flue gas flow direction, thus forming a gradually narrowing flue gas collection chamber. The flue gas outlet interface is vertically arranged at the top center of the top cover and is interconnected. The bottom end of the top cover is sealed and installed on the top surface of the housing and is interconnected. The flue gas inlet end consists of a flue gas inlet duct and a bottom connecting cover, which are integrally formed. The flue gas inlet duct is inclined downward and arranged on one side of the bottom connecting cover and is interconnected as a guide section. The central axis of the flue gas inlet duct forms an acute angle with the horizontal plane. The specific inclination angle design reduces the impact of the inlet flow velocity and realizes the uniform diffusion of flue gas into the gap of the heat exchange pipe array. The end of the flue gas inlet duct near the inside of the bottom connecting cover extends along the flue gas flow direction and exceeds the inner wall surface of the bottom connecting cover. The top end of the bottom connecting cover is sealed and installed on the bottom end surface of the housing and is interconnected. The top surface of the water collector is sealed and installed on the bottom end surface of the bottom connecting cover and is interconnected.

[0013] The enhanced heat exchange tube array includes a heat exchange pipe array and a reinforcing fin array. The heat exchange pipe array includes several heat exchange pipes arranged vertically at intervals, with the axial direction of each heat exchange pipe along the horizontal direction. The reinforcing fin array includes several reinforcing fins, which contain longitudinal corrugated fins and transverse annular fins. The longitudinal corrugated fins guide the flue gas to form a spiral sweeping flow along the axial direction of the heat exchange pipes, while the transverse annular fins enhance the turbulence intensity by expanding the heat exchange area and inducing horseshoe vortices. Each reinforcing fin is fitted onto its respective heat exchange pipe, and each spiral turbulence structure is installed inside its respective heat exchange pipe. Two segmented tube plates are vertically arranged on both symmetrical sides of the enhanced heat exchange tube array and are spaced apart from the inner wall of the housing. Each segmented tube plate has several pipe through holes arranged in a uniform array to form a pipe through hole array, ensuring the uniformity of flow distribution in each heat exchange pipe. The two pipe through holes facing each other on the two segmented tube plates are respectively sealed and connected to the two ends of a heat exchange pipe.

[0014] The two segmented tube sheets are parallel to and close to one side of the housing where the inlet and outlet water interfaces are located. The top and bottom edges of each segmented tube sheet are connected to the top and bottom edges of the side of the housing they are close to by horizontal partitions. Each segmented tube sheet is staggered with horizontal partitions and upward-sloping V-shaped flue gas baffles. The partitions are all located on the side of the segmented tube sheet close to the housing and between the pipe holes of adjacent layers. The partitions are sealed between the side wall of the housing and the segmented tube sheet, thereby dividing the inner cavity of the housing into at least three independent flow guiding chambers to form a multi-pass zigzag water flow channel, forcing the cooling water to flow through different chambers in sequence and zigzag multiple times. This design significantly extends the effective path of water flow in the heat exchange zone, eliminating localized low-temperature zones caused by uneven distribution. The V-shaped flue gas baffles are all located on the side of the partitioned tube sheet away from the housing and between the pipe openings of adjacent layers. These V-shaped baffles are interspersed between the reinforcing ribs of adjacent layers and do not connect to the opposite partitioned tube sheet. Only one V-shaped flue gas baffle is interspersed between the reinforcing ribs of adjacent layers. The V-shaped flue gas baffles are distributed in a continuous wavy pattern in the vertical direction. The first layer of pipe openings on the partitioned tube sheet closest to the water inlet is located between two partitions, i.e., below. The pipe openings in each layer are arranged alternately from top to bottom as baffles and V-shaped flue gas baffles. The last layer of pipe openings on a partitioned pipe plate near the water outlet is located between two baffles, meaning that from bottom to top, baffles and V-shaped flue gas baffles are arranged alternately. The vertically continuous adjacent V-shaped flue gas baffles form a periodic contraction-expansion flow channel structure. When the flue gas passes through the V-shaped flue gas baffles, the flow area decreases, and then the flow area increases again, thus forming a periodic contraction-expansion flow channel. The contraction section accelerates the flue gas to increase the convection intensity, and the expansion section reduces energy loss through pressure recovery.

[0015] Each of the aforementioned V-shaped flue gas baffles also has a square guide hole at the bend point on the side near the partition tube sheet.

[0016] Each of the aforementioned spiral turbulence structures includes several arc-shaped baffles. The periphery of each baffle is connected to the inner wall of the heat exchange pipe and has an inclination angle with the vertical plane. The baffles are arranged alternately in opposite directions along the axial and longitudinal intervals to disrupt the laminar boundary layer through radial secondary flow.

[0017] The top side of the enclosure is equipped with a horizontal water inlet, and the bottom side is equipped with a horizontal water outlet. Cooling water and flue gas are fed into the condensation heat exchange module inside the enclosure for internal and external heat exchange, thus forming a counter-current heat exchange channel. Flue gas flows in through the flue gas inlet, is guided by the flow guide component inside the enclosure, and flows to the top of the enclosure. After exchanging heat with the condensation heat exchange module, it flows out from the flue gas outlet. Some of the corrosive gases carried in the flue gas are liquefied and flow to and discharged from the water collector at the bottom.

[0018] The condenser shell-and-tube heat exchanger is also coated with an alumina-based wear-resistant ceramic coating to resist the high-temperature corrosion of acidic components in sulfur-containing flue gas.

[0019] The water collector includes a flow channel and a condensate discharge pipe. The flow channel is funnel-shaped to form a gradually narrowing condensate collection chamber. The top of the flow channel and the bottom of the bottom connecting cover at the flue gas inlet are sealed and connected. The bottom of the flow channel is sealed and connected to one end of the condensate discharge pipe. The flow channel and the condensate discharge pipe form a siphon-type sealing structure to achieve rapid collection and sealed discharge of acidic condensate.

[0020] The internal flow guide slope of the flow guide channel is coated with a nano-hydrophobic coating to reduce droplet adhesion; a pH monitoring sensor is also integrated at the connection between the flow guide channel and the condensate drain pipe to detect the acidity of the condensate in real time and link the control system to dynamically adjust the sewage discharge frequency.

[0021] The beneficial effects of this invention are:

[0022] This invention breaks down the laminar boundary layer through a spiral-fin composite heat transfer structure, and improves heat transfer uniformity by combining it with a multi-pass, reversible water flow channel. The synergistic effect of the V-shaped turbulence component and the converging flow channel significantly reduces the flue gas temperature to below the dew point. A dual protection system of corrosion-resistant materials and nano-coatings effectively blocks acidic condensate corrosion, and the modular design reduces manufacturing costs by eliminating the need for additional protective chambers. This device achieves a balance between improved thermal efficiency and corrosion resistance and economic benefits, meeting the long-term reliable operation requirements of household gas appliances. Attached Figure Description

[0023] Figure 1This is an exploded view of the condenser shell-and-tube heat exchanger provided in the embodiments of this application.

[0024] Figure 2 This is a top cross-sectional view of the condenser shell-and-tube heat exchanger provided in the embodiments of this application;

[0025] Figure 3 This is a front cross-sectional view of the condenser shell-and-tube heat exchanger provided in the embodiments of this application;

[0026] Figure 4 This is a left-side cross-sectional view of the condenser shell-and-tube heat exchanger provided in the embodiments of this application.

[0027] Figure 5 This is a partial front view of the partitioned tube sheet of the condenser shell-and-tube heat exchanger provided in the embodiments of this application.

[0028] Figure 6 This is a partial schematic diagram of the partitioned tube sheet of the condenser shell-and-tube heat exchanger provided in the embodiments of this application;

[0029] Figure 7 This is a partial schematic diagram of the heat exchange pipes of the condenser shell-and-tube heat exchanger provided in the embodiments of this application.

[0030] In the diagram: 1. Flue gas exhaust end; 11. Flue gas outlet interface; 12. Top cover; 2. Box body; 21. Water inlet interface; 22. Water outlet interface; 3. Segmented tube sheet; 31. V-shaped flue gas baffle; 32. Pipe through-hole array; 33. Baffle plate; 34. Guide hole; 4. Heat exchange pipe array; 5. Reinforced fin array; 6. Spiral baffle structure; 71. Flue gas inlet duct; 72. Bottom connecting cover; 8. Water collector; 81. Guide channel; 82. Condensate discharge pipe. Detailed Implementation

[0031] In this invention, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0032] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0033] Furthermore, in the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0034] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] This invention provides a condenser shell-and-tube heat exchanger for household gas water heaters, the specific structure and working principle of which are strictly based on... Figures 1 to 7 The components shown are implemented as described below. The functions and collaborative workflows of each component are described in detail below with reference to the accompanying drawings to ensure that those skilled in the art can accurately implement this technical solution.

[0037] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the condenser shell-and-tube heat exchanger of the present invention includes a housing 2, a condenser heat exchange module, and a water collector 8. The housing 2 is used for the flow of flue gas and water during heat exchange. The condenser heat exchange module is installed inside the housing 2 and includes an enhanced heat exchange tube array and a flow guiding assembly. The flow guiding assembly includes two partitioned tube sheets 3 for flow guiding and several spiral turbulence structures 6. The enhanced heat exchange tube array is located between the two partitioned tube sheets 3, and each spiral turbulence structure 6 is disposed inside the enhanced heat exchange tube array. The two partitioned tube sheets 3 also have... Several V-shaped flue gas baffles 31 are inclined and staggered among the enhanced heat exchange tube array. Each V-shaped flue gas baffle 31 forms a continuous wave-shaped flow channel, and the water flow is multi-passed and deflected through the partitioned tube sheet 3. The heating water of the condensing heat exchange module is guided by the flow guide components on both sides of the box 2 and discharged from the other side of the box near the bottom. The water collector 8 is installed below the box 2 and directly below the condensing heat exchange module. It is sealed and connected to the box 2 and collects and discharges the liquefied flue gas through the gradually narrowing condensate collection chamber. The condensing shell-and-tube heat exchanger is made of stainless steel or aluminum alloy and adopts a modular cubic frame. The box 2 is the core heat exchange chamber. It has a cubic structure with reinforcing ribs at the corners and passivated key welds.

[0038] like Figure 1 As shown, the upper and lower ends of the housing 2 are respectively sealed with a flue gas discharge end 1 and a flue gas inlet end. The flue gas discharge end 1 is integrally formed by a flue gas outlet interface 11 and a detachable top cover 12. The cross-section of the top cover 12 decreases linearly from bottom to top along the flue gas flow direction, thus forming a gradually narrowing flue gas collection chamber. The outlet flow rate is stabilized by the Venturi effect. The flue gas outlet interface 11 is vertically arranged at the top center of the top of the top cover 12 and is interconnected. The bottom end of the top cover 12 is sealed and installed on the top surface of the housing 2 and is interconnected. The flue gas inlet end is integrally formed by a flue gas inlet duct 71 and a bottom connecting cover 72. The flue gas inlet duct 71 is inclined downward and arranged on one side of the bottom connecting cover 72 and is interconnected as a guide section. The central axis of the flue gas inlet duct 71 is perpendicular to the water... A 35-45° acute angle is formed between the planes. The specific tilt angle design reduces the impact of the inlet flow velocity and realizes uniform diffusion of flue gas into the gap of the heat exchange pipe array 4. One end of the flue gas inlet duct 71 near the inside of the bottom connecting cover 72 extends along the flue gas flow direction and exceeds the inner wall surface of the bottom connecting cover 72. Specifically, the length exceeding the inner diameter of the flue gas inlet duct 71 by 0.3-0.4 times serves as a guide extension section. The function of the guide extension section is to prevent flue gas condensate from flowing down the wall surface and back into the flue gas inlet duct 71. The extension direction of the guide extension section is the same as the central axis of the guide section, forming a continuous and smooth transition. The top end of the bottom connecting cover 72 is sealed and installed on the bottom end face of the housing 2 and is interconnected. The top end of the water collector 8 is sealed and installed on the bottom end face of the bottom connecting cover 72 and is interconnected.

[0039] The water collector 8 includes a flow guide channel 8 and a condensate discharge pipe 82. The flow guide channel 8 is funnel-shaped, forming a gradually narrowing condensate collection chamber. The flow guide slope of the flow guide channel 8 forms an inclination angle of 15°-45° with the horizontal plane. The top of the flow guide channel 8 is sealed and connected to the bottom of the bottom connecting cover 72 at the flue gas inlet. The bottom of the flow guide channel 8 is sealed and connected to one end of the condensate discharge pipe 82. The flow guide channel 8 and the condensate discharge pipe 82 form a siphon-type sealing structure, realizing the rapid collection and sealed discharge of acidic condensate. The inner flow guide slope of the flow guide channel 8 is coated with a nano-hydrophobic coating to reduce droplet adhesion. A pH monitoring sensor is also integrated at the connection between the flow guide channel 8 and the condensate discharge pipe 82 to detect the acidity of the condensate in real time and link the control system to dynamically adjust the discharge frequency.

[0040] like Figure 2 As shown, a horizontal water inlet 21 is provided on one side of the top of the housing 2, and a horizontal water outlet 22 is provided on the other side of the bottom of the housing 2. Cooling water and flue gas are introduced into the condensation heat exchange module inside the housing 2 for internal and external heat exchange, thus forming a counter-current heat exchange channel. Flue gas flows in through the flue gas inlet end, is guided by the flow guiding component inside the housing 2 and flows to the top of the housing 2. After exchanging heat with the condensation heat exchange module, it flows out from the flue gas outlet end 1. Some of the corrosive gases carried in the flue gas are liquefied and flow to and discharged from the water collector 8 at the bottom.

[0041] The enhanced heat exchanger array includes a heat exchanger pipe array 4 and a reinforcing fin array 5. The heat exchanger pipe array 4 includes several heat exchanger pipes arranged at intervals in the vertical direction, with the axial direction of each heat exchanger pipe along the horizontal direction. The reinforcing fin array 5 includes several reinforcing fins, which contain longitudinal corrugated fins and transverse annular fins. The longitudinal corrugated fins guide the flue gas to form a spiral swept flow along the axial direction of the heat exchanger pipes, while the transverse annular fins enhance the turbulence intensity by expanding the heat exchange area and inducing horseshoe vortices. Each reinforcing fin is fitted onto its respective heat exchanger pipe, such as... Figure 7 As shown, each spiral turbulence structure 6 is installed inside its own heat exchange pipe; two segmented tube plates 3 are vertically arranged on both sides of the enhanced heat exchange tube array and are spaced apart from the inner wall of the box 2. Each segmented tube plate 3 has several pipe through holes arranged in a uniform array to form a pipe through hole array 32, such as... Figure 5 As shown, this ensures uniform flow distribution in each heat exchange pipe; the two pipe through holes on the two partitioned tube sheets 3 are respectively sealed and connected to the two ends of a heat exchange pipe.

[0042] like Figure 3As shown, each spiral turbulence structure 6 includes several arc-shaped baffles. The periphery of each baffle is connected to the inner wall of the heat exchange pipe and has a 10° inclination angle with the vertical plane. The baffles are arranged alternately in opposite directions along the axial and longitudinal directions. The axial spacing between adjacent baffles is 0.8-0.9 times the inner diameter of the heat exchange pipe. The baffles induce radial secondary eddies by periodically changing the direction of water flow, continuously scouring the thermal boundary layer of the heat exchange pipe wall, thereby destroying the laminar boundary layer through radial secondary flow.

[0043] Two partitioned tube sheets 3 are parallel to and close to one side of the housing 2 where the inlet port 21 and outlet port 22 are located. The top and bottom edges of each partitioned tube sheet 3 are connected to the top and bottom edges of the side of the housing 2 to which it is located by horizontal partitions 33. Each partitioned tube sheet 3 has horizontal partitions 33 and upwardly inclined V-shaped flue gas baffles 31 arranged alternately. Each V-shaped flue gas baffle 31 is composed of a set of symmetrical inclined guide plates. The plane of the guide plates is perpendicular to the cross section of the heat exchange pipe. The horizontal direction is inclined at an acute angle of 1°-10°, and the plane of the guide plate is arranged in a double-inclination arrangement with the axial direction of the heat exchange pipe at an acute angle of 1°-10°; the partitions 33 are all located on the side of the partition tube plate 3 near the box 2 and between the pipe through holes of the adjacent layers. The partitions 33 are sealed between the side wall of the box 2 and the partition tube plate 3, thereby dividing the inner cavity of the box 2 into at least three independent guide chambers to form a multi-pass zigzag water flow channel, forcing the cooling water to flow through different chambers in sequence and zigzag multiple times. This design significantly extends the effective path of water flow in the heat exchange zone, eliminating localized low-temperature zones caused by uneven distribution. The V-shaped flue gas baffles 31 are all located on the side of the partitioned tube sheet 3 away from the housing 2 and between the pipe openings of adjacent layers. The V-shaped flue gas baffles 31 are interspersed between the reinforcing ribs of adjacent layers and do not connect to the opposite partitioned tube sheet 3. Only one V-shaped flue gas baffle 31 is interspersed between the reinforcing ribs of adjacent layers. Each V-shaped flue gas baffle 31 is distributed in a continuous wavy pattern in the vertical direction. The first layer of pipe openings on a partitioned tube sheet 3 near the water inlet 21 is located between two partitions 33, i.e., below each... The through holes of the layered pipes are arranged alternately from top to bottom as baffles 33 and V-shaped flue gas baffles 31. The last layer of through holes on a partitioned tube sheet 3 near the water outlet 22 is located between two baffles 33, that is, from bottom to top, baffles 33 and V-shaped flue gas baffles 31 are arranged alternately. The adjacent V-shaped flue gas baffles 31, which are continuously distributed vertically, form a periodic contraction-expansion flow channel structure. When the flue gas passes through the V-shaped flue gas baffles 31, the flow area decreases, and then the flow area increases again, thus forming a periodic contraction-expansion flow channel. The contraction section accelerates the flue gas to increase the convection intensity, and the expansion section reduces energy loss through pressure recovery.

[0044] like Figure 5 and Figure 6As shown, each V-shaped flue gas baffle 31 has a square guide hole 34 at the bend point on the side near the partition tube plate 3. The guide hole 34 can balance the flue gas flow field distribution between the heat exchange tube array 4 and guide the condensate to the center. It can also allow the condensate in the flue gas to flow down smoothly and not accumulate in the V-shaped flue gas baffle 31, which would cause corrosion. At the same time, it can also reduce the stress of the V-shaped flue gas baffle 31 and extend its service life.

[0045] The condenser shell-and-tube heat exchanger is also coated with an alumina-based wear-resistant ceramic coating to resist the high-temperature corrosion of acidic components in sulfur-containing flue gas. In practice, there are two scenarios. First, if the heat exchanger is made of stainless steel, since the thermal conductivity of stainless steel and the coating is similar, adding the coating will not significantly affect the heat exchange efficiency. Therefore, in this case, all parts in contact with the flue gas need to be coated with an alumina-based wear-resistant ceramic coating. Second, if the heat exchanger is made of aluminum, since the thermal conductivity of aluminum is much greater than that of the coating, in order to balance corrosion and heat exchange efficiency, all parts in contact with the flue gas, except for the heat exchange tubes 4 and the reinforced fin array 5, need to be coated with an alumina-based wear-resistant ceramic coating.

[0046] The heat exchange method of the condenser shell-and-tube heat exchanger of the present invention is as follows:

[0047] Regarding the cooling water flow and heat exchange process: Cooling water enters the primary guide chamber of the partitioned tube sheet 3 through the inlet port 21. Constrained by baffles 33, the water flows through the first layer of heat exchange pipes, where alternating counter-current baffles on the inner wall spiral turbulence structure 6 periodically agitate the flow. When the water impacts the inclined surface of the baffles, some fluid deflects along the baffle surface, forming a radial secondary flow. This secondary flow continuously scours the thermal boundary layer of the heat exchange pipe wall, significantly reducing the thickness of the laminar sublayer. Simultaneously, the expansion-contraction flow channel sequence between the baffles enhances turbulence intensity while maintaining reasonable friction resistance. After absorbing heat, the water flows back to the secondary chamber, sequentially passing through subsequent heat exchange pipe layers to complete a multi-stage heating process, and finally exits from the outlet port 22.

[0048] Regarding the flue gas flow and phase change triggering mechanism: High-temperature flue gas enters the bottom of the housing 2 through the flue gas inlet duct 71. The specific inclination angle design of the guide section deflects the initial flow direction of the flue gas, and the wear-resistant coating on the inner wall of the guide extension section resists the erosion of acidic components. The two work together to reduce the inlet kinetic energy and achieve uniform diffusion of the flue gas. When the flue gas flows upward through the gaps in the heat exchange pipe array 4, the double-inclined guide plates of the V-shaped flue gas baffle 31 force the flue gas to generate a three-dimensional composite motion: the axial component maintains the main upward flow direction; the radial component enhances the impact strength of the flue gas on the reinforcing rib array 5; and the tangential component forms a rotating flow to inhibit particle deposition.

[0049] As the flue gas temperature drops below the dew point along the path, water vapor undergoes a phase change on the surface of the reinforced fin array 5, releasing latent heat. The liquid water generated during the phase change reacts with CO2 and NO in the flue gas.x The acidic gases dissolve to form a corrosive condensate. This liquid flows down the wall of the heat exchanger array 4 under gravity, and, guided by the V-shaped flue gas baffles 31, converges at the centerline of the partitioned tube sheet 3 via the guide holes 34. The guide holes 34 simultaneously balance the flue gas flow field distribution between the heat exchanger array 4, eliminating dead zones in the corners.

[0050] For the condensate dynamic management system, acidic condensate drips into the guide channel 81 of the collector 8. A specific angled slope design forms a gravity-fed channel, and the surface nano-hydrophobic coating, through its low surface energy at the molecular level, allows the condensate to rapidly slide in a bead-like condensation form. This mechanism significantly shortens the contact time between the corrosive medium and the metal wall, reducing the risk of pitting corrosion. A pH monitoring sensor integrated into the guide channel 81 detects the condensate acidity in real time. When the pH value falls below a set threshold, the linkage control system initiates an accelerated drainage program to prevent acidic liquid retention and material failure. The condensate is centrally discharged through the condensate drain pipe 82, which features a siphon-sealed structure that effectively prevents flue gas leakage during drainage.

[0051] For the optimized design of flue gas emissions, the cooled flue gas enters a tapered flue gas collecting chamber formed by the detachable top cover 12 and the housing 2. The cross-sectional area of ​​the chamber decreases linearly along the flow direction, maintaining a reasonable residual pressure near the outlet through the Venturi effect. This design significantly reduces local pressure drop losses and decreases the energy consumption of the induced draft fan. The flue gas is finally discharged stably from the flue gas outlet interface 11, and its temperature gradient distribution forms a significant temperature difference with the counter-flowing cooling water, enhancing the sensible heat recovery efficiency.

[0052] Regarding the implementation details of material and structural reliability: The heat exchanger is entirely constructed of stainless steel or corrosion-resistant aluminum alloy, materials possessing excellent mechanical strength and resistance to intergranular corrosion. Reinforcing ribs are added to the corners of the cube to improve overall bending stiffness through stress dispersion, effectively resisting external vibration loads. The multi-chamber integrated design of the segmented tube sheet 3 significantly reduces the number of welding nodes, lowering the risk of manufacturing defects. Critical welds undergo electrolytic passivation treatment to form a dense oxide film, blocking chloride ion penetration paths. The casing 2 and shell are connected for airtightness through continuous welding, and the removable top cover 12 uses a flange with a high-temperature ceramic fiber gasket to ensure high-temperature sealing performance under maintenance conditions.

[0053] The segmented tube sheet 3 extends the effective heat exchange path through multi-pass reversing water flow channels, eliminating local low-temperature zones; the periodic flow channel design of the V-shaped flue gas baffle 31 optimizes the flue gas pressure loss distribution; the spiral baffle structure 6 and the reinforced fin array 5 work together to break the two-fluid thermal boundary layer; the nano-hydrophobic coating and pH linkage mechanism construct a dynamic anti-corrosion system; and the tapered outlet chamber reduces the energy consumption of the induced draft fan. All subsystems are spatially integrated to form a compact cubic layout, achieving a balance between latent heat recovery efficiency and equipment reliability while eliminating the traditional neutralization system and additional cavities.

[0054] This embodiment fully discloses the technical details and working logic of the structure shown in the accompanying drawings. Any equivalent design changes based on the same principle, including but not limited to adaptive adjustment of the guide vane angle, increase or decrease in the number of guide chambers, and optimization of the rib arrangement, are all within the scope of protection of the claims of this invention.

Claims

1. A condensing shell and tube heat exchanger, characterized in that, The utility model relates to a kind of condensing heat exchange module and condensing heat exchange device, including: Box (2) for the flow of flue gas and water when heat exchange; Condensing heat exchange module is installed in the inside of box (2), and condensing heat exchange module includes enhanced heat exchange pipe array and flow guide assembly, flow guide assembly includes two split format pipe plate (3) for flow guide and several spiral turbulence structures (6), enhanced heat exchange pipe array is located between two split format pipe plate (3), each spiral turbulence structure (6) is arranged inside the enhanced heat exchange pipe array, several V-shaped flue gas turbulence sheets (31) are also obliquely arranged on two split format pipe plate (3) and are staggered between enhanced heat exchange pipe array, and each V-shaped flue gas turbulence sheet (31) forms continuous wave-shaped flow channel; Water collector (8) is installed below box (2) and is located directly below condensing heat exchange module, and is sealed with box (2) and is collected and discharged by tapered condensed water collection chamber after liquefaction flue gas.

2. The condensing tube-in-shell heat exchanger of claim 1, wherein: The upper and lower ends of the box (2) are respectively sealed with a flue gas discharge end (1) and a flue gas inlet end, the flue gas discharge end (1) is composed of a flue gas outlet interface (11) and a detachable top cover (12) and is integrally formed, the cross section of the top cover (12) decreases linearly from bottom to top along the flue gas flow direction to form a tapered flue gas collection chamber, the flue gas outlet interface (11) is vertically arranged at the top center of the top cover (12) and is in communication with each other, and the bottom end of the top cover (12) is sealed and installed on the top end face of the box (2) and is in communication with each other;The flue gas inlet end is composed of a flue gas inlet guide pipe (71) and a bottom connecting cover (72) and is integrally formed, the flue gas inlet guide pipe (71) is obliquely arranged on one side of the bottom connecting cover (72) and is in communication with each other, the central axis of the flue gas inlet guide pipe (71) forms an acute angle with the horizontal plane, the end of the flue gas inlet guide pipe (71) close to the inside of the bottom connecting cover (72) extends along the flue gas flow direction and exceeds the inner wall surface of the bottom connecting cover (72), the top end of the bottom connecting cover (72) is sealed and installed on the bottom end face of the box (2) and is in communication with each other, and the top end face of the water collector (8) is sealed and installed on the bottom end face of the bottom connecting cover (72) and is in communication with each other.

3. The condensing tube and shell heat exchanger of claim 2, wherein: The enhanced heat exchange pipe array includes a heat exchange pipe array (4) and a reinforced fin array (5), the heat exchange pipe array (4) includes a plurality of heat exchange pipes arranged in vertical direction, the axial direction of each heat exchange pipe is along the horizontal direction, the reinforced fin array (5) includes a plurality of reinforced fins, each reinforced fin is sleeved on a corresponding heat exchange pipe, and each spiral turbulence structure (6) is installed inside a corresponding heat exchange pipe;Two split format pipe plates (3) are vertically arranged on the symmetrical sides of the enhanced heat exchange pipe array and are spaced from the inner wall surface of the box (2), a plurality of pipe through holes are uniformly arranged on each split format pipe plate (3) to form a pipe through hole array (32), and the two pipe through holes opposite to each other on the two split format pipe plates (3) are in sealed communication with the two ends of a corresponding heat exchange pipe.

4. The condensing tube-in-shell heat exchanger of claim 3, wherein: Two said sub-format tube plates (3) are respectively parallel and close to one side of the tank (2) where the water inlet interface (21) and the water outlet interface (22) are located, the top edge and the bottom edge of each sub-format tube plate (3) are respectively connected with the top edge and the bottom edge of the side of the tank (2) through horizontal partition plates (33), and the horizontal partition plates (33) and the upwardly inclined V-shaped flue gas spoiler (31) are alternately arranged on each sub-format tube plate (3); the partition plates (33) are located between the adjacent layers of pipeline through holes on the side of the sub-format tube plate (3) close to the tank (2), and the partition plates (33) are sealingly connected between the side wall of the tank (2) and the sub-format tube plate (3) to divide the inner cavity of the tank (2) into independent flow guide chambers to form a multi-pass and return type water flow channel; the V-shaped flue gas spoiler (31) is located between the adjacent layers of pipeline through holes on the side of the sub-format tube plate (3) away from the tank (2), the V-shaped flue gas spoiler (31) is inserted between the adjacent layers of reinforcing ribs and is not connected to the other sub-format tube plate (3) opposite to it, and each V-shaped flue gas spoiler (31) is continuously and wavelike distributed in the vertical direction; the first layer of pipeline through holes on the sub-format tube plate (3) close to the water inlet interface (21) are located between two partition plates (33), the last layer of pipeline through holes on the sub-format tube plate (3) close to the water outlet interface (22) are located between two partition plates (33); a periodic contraction-expansion flow channel structure is formed between adjacent V-shaped flue gas spoilers (31).

5. The condensing tube-in-shell heat exchanger of claim 4, wherein: Each said V-shaped flue gas spoiler (31) is further provided with a flow guide through hole (34) at the bending point close to one side of the sub-format tube plate (3).

6. The condensing tube-in-shell heat exchanger of claim 3, wherein: Each said spiral spoiler structure (6) comprises a plurality of arc-shaped baffles, the circumferential edge of each baffle is connected to the inner wall surface of the heat exchange pipeline and has an inclination angle with the vertical plane, and each baffle is alternately and reversely arranged along the axial and longitudinal directions to form a radial secondary flow to destroy the laminar boundary layer.

7. The condensing tube-in-shell heat exchanger of claim 1, wherein: The top side of the tank (2) is further provided with a horizontal water inlet interface (21), and the bottom side of the tank (2) is further provided with a horizontal water outlet interface (22), the cooling water and the flue gas are jointly introduced into the condensation heat exchange module inside the tank (2) to perform internal and external heat exchange, thereby forming a counterflow heat exchange channel.

8. The condensing tube-in-shell heat exchanger of claim 1, wherein: The condensation tube shell type heat exchanger is further provided with an alumina-based wear-resistant ceramic coating.

9. The condensing tube-in-shell heat exchanger of claim 2, wherein: The water collector (8) comprises a flow guide channel (8) and a condensate water discharge pipe (82), the flow guide channel (8) is funnel-shaped to form a tapered condensate water collection chamber, the top end of the flow guide channel (8) is sealingly connected and communicated with the bottom end of the bottom connecting cover (72) of the flue gas inlet end, and the bottom end of the flow guide channel (8) is sealingly connected to one end of the condensate water discharge pipe (82).

10. The condensing tube-in-shell heat exchanger of claim 9, wherein: The inner flow guide slope of the flow guide channel (8) is coated with a nano-hydrophobic coating; the connection between the flow guide channel (8) and the condensate water discharge pipe (82) is further integrated with a pH monitoring sensor.

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