A SHS gas boiler with straight finned tube special-shaped combined multi-mechanism coupling enhanced heat exchange

Abstract

The application discloses a SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange, which comprises a full premix water-cooled burner, upper and lower boiler drums, a furnace membrane water-cooled wall, a front light tube bundle and a straight fin tube special-shaped combined tube bundle group. The full premix water-cooled burner ignites and burns after mixing air and gas on the inner surface of a water-cooled combustion head; high flue gas is cooled by the furnace membrane water-cooled wall and the front light tube bundle, and then enters a straight fin tube special-shaped combined tube bundle group formed by symmetric fork-shaped straight fin tubes and front and rear double-wing-shaped longitudinal flat fin tubes to form a multi-mechanism coupled enhanced heat exchange tube row, and the flue gas is discharged from the boiler body after being gathered. x The full premix water-cooled combustion reduces the combustion temperature to realize ultra-low NOx emission, the flame length is short, and the depth of the furnace is only one tenth of that of a traditional diffusion combustion boiler; the straight fin tube special-shaped combined tube bundle group significantly improves the heat exchange coefficient of the tube bundle group, greatly reduces the longitudinal row number of the water pipes, is only one tenth of that of a traditional SZS longitudinal row number, and significantly reduces the steel consumption of the boiler, welding workload, manufacturing cost and carbon emission.

Description

Technical Field

[0001] This invention relates to the field of gas-fired boiler equipment technology, specifically to an SHS gas-fired boiler with a multi-mechanism coupling enhanced heat exchange using a combination of straight finned tubes and irregular shapes. Background Technology

[0002] To meet the needs of all parties, natural gas, as a low-carbon and clean energy source between traditional fossil fuels and renewable energy, has obvious advantages such as lower carbon emissions than coal and oil and lower cost than renewable energy. In the historical process of energy structure transformation, natural gas will play a crucial role, and its consumption is expected to continue to grow over the next 15 years.

[0003] In recent years, with the rise of new materials, new processes, and emerging combustion technologies, the market demand for ultra-low nitrogen technology retrofitting, and the practical need to achieve carbon emission targets, water-tube gas-fired boilers face significant challenges, making transformation and upgrading inevitable. Traditional SHS (Self-Hardening, Hybridizing, and Hardening) gas-fired boilers have a simple and compact structure, characterized by large water volume and safe water circulation. Therefore, this structure is often used in the manufacture of large-tonnage gas-fired boilers of 10 tons or more. However, the design of existing SHS water-tube gas-fired boilers is relatively primitive, with no heat exchange enhancement measures taken for the convection tube bundles. As the flue gas temperature decreases, the heat exchange and heat transfer coefficient along the flue gas flow direction drop rapidly. Therefore, the boiler needs to use a large number of convection tube bundles to reduce the exhaust gas temperature to achieve sufficiently high boiler thermal efficiency, resulting in high steel consumption and welding workload. This drawback is even more pronounced because this structure is frequently used in the manufacture of large-tonnage gas-fired boilers. At the same time, existing SHS gas-fired boilers are basically designed for diffusion burners, resulting in a huge boiler furnace space, further increasing boiler steel consumption and welding workload.

[0004] In recent years, surface burner technology has developed rapidly, resulting in a variety of forms. Water-cooled burners, porous ceramic plate burners, and metal fiber or wire mesh burners offer a large adjustability ratio, uniform flame, and flame temperatures below 1100℃, suppressing the formation of thermal nitrogen oxides (NOx), with NOx emissions below 30mg, meeting the latest environmental standards. As a type of surface burner, the planar burner only requires one furnace wall for installation. The burner distributor head has a short flame length, hovering only within 200mm behind the combustion plane, thus requiring even less furnace space. Currently, planar burners are mainly used in small-capacity boilers such as gas-fired hot water boilers and gas-fired wall-hung boilers, but have little application in the large-capacity pressurized gas-fired boiler market. The main reason is that although planar burners can be arranged using only one furnace wall of the boiler, the specific combination schemes that organically combine the two for water-tube gas boilers of different structures have not yet been well explored. At the same time, using part of the heat exchange tube bundle of the water-tube boiler as the burner head of the planar burner to achieve water-cooled fully premixed combustion is an effective way to reduce boiler nitrogen oxide emissions. However, due to the combustion characteristics of fully premixed combustion itself, its large size is subject to many limitations in order to ensure the safety of the planar burner, which is contrary to the characteristic of water-tube boilers being easy to scale up. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems existing in the current gas-fired boiler technology and provide a multi-mechanism enhanced heat exchange SHS gas-fired boiler, which significantly improves the heat exchange coefficient of water tubes, reduces the number of boiler water tubes, and provides a modular combination scheme of fully premixed water-cooled burners and large-capacity SHS boilers. This enables fully premixed water-cooled combustion to reduce combustion temperature and nitrogen oxide emissions, reduces the length of the combustion flame to reduce the furnace volume, and overall reduces boiler steel consumption and welding workload, thereby reducing boiler manufacturing costs.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: an SHS gas-fired boiler with multi-mechanism coupling and enhanced heat exchange via straight finned tube irregular combination, comprising a fully premixed water-cooled burner, an upper drum, a lower drum, a front bare tube bundle, a straight finned tube irregular combination bundle group, a front water-cooled wall, and two side water-cooled walls. The fully premixed water-cooled burner is mounted on the front water-cooled wall to act as a water-cooled combustion tube bank forming a water-cooled burner head. The front water-cooled wall has a bare tube bundle at the outlet docking position of the fully premixed water-cooled burner, and the remaining positions are membrane water-cooled wall structures welded from bare tubes and flat steel. The upper and lower drums are located near the side water-cooled walls on both sides. Two sets of water-cooled wall headers are installed at the top and bottom of the cold wall, which are connected to the water-cooled walls on both sides. The front water-cooled wall, the front bare tube bundle, and the side water-cooled wall surround and form the furnace space. At the outlet of the furnace space, bare tube bundles and several rows of straight finned tube irregular combination bundles are arranged in sequence along the flue gas flow direction. The upper and lower ends of the bare tube bundles, straight finned tube irregular combination bundles, and the front water-cooled wall are respectively connected to the upper drum and the lower drum. The flue gas outlet is connected to the furnace space and the economizer. Straight finned tube irregular combination bundles are installed in the economizer. The boiler feedwater is heated by the economizer and sent into the upper drum, thus entering the water circulation loop formed by the upper drum and the lower drum.

[0007] The straight finned tube irregular combination tube bundle group is formed by alternating arrangement of two types of finned tubes with the same diameter: symmetrical forked straight finned tubes and symmetrical double-wing longitudinal straight finned tubes. The tubes in the same row and the adjacent row that are adjacent to the symmetrical double-wing longitudinal straight finned tubes are all symmetrical forked straight finned tubes. Both types of finned tubes are only provided with fins in the vertical tube sections. Membrane wall structures are used in the elbows and the parts connecting to the boiler drum. The fins of two adjacent symmetrical forked straight finned tubes wrap around the symmetrical double-wing longitudinal straight finned tubes on the left and right, forming a flue gas flow channel for enhanced convective heat transfer between the symmetrical forked straight finned tubes and the symmetrical double-wing longitudinal straight finned tubes.

[0008] In the straight-finned tube irregular combination bundle group, the symmetrical forked straight-finned tubes in each row correspond to the symmetrical double-wing longitudinal straight-finned tubes in the adjacent row in the front-back direction, forming a staggered arrangement. Several rows of tube bundles constitute the straight-finned tube irregular combination bundle group. Between each pair of four adjacent tube bundles, a hexagonal cross-section is formed, consisting of two forked straight fin segments AB and DE, two longitudinal straight fin segments BC and EF, and two smooth tube arc segments CD and FA. During dynamic operation, this hexagonal cross-section has only one flue gas inlet and one flue gas outlet. The entire hexagonal cross-section plane develops into a hexagonal prism along the axis of the four tube bundles.

[0009] The symmetrical forked straight finned tube is composed of four longitudinal straight fins symmetrically attached to both sides of the tube in a forked shape. The symmetrical double-wing longitudinal straight finned tube is composed of two longitudinal straight fins symmetrically attached to both sides of the tube in a wing shape. The thickness of a single longitudinal straight fin is not less than the wall thickness of the tube. The symmetrical forked straight finned tube and the symmetrical double-wing longitudinal straight finned tube are formed by integral rolling or forging into finned tubes or by fully welding longitudinal flat steel onto the tube.

[0010] A front-mounted light tube bundle is arranged in front of the straight finned tube irregular combination tube bundle group to reduce the temperature of the flue gas entering the straight finned tube irregular combination tube bundle group.

[0011] Since the front side of the straight finned tube irregular combination tube bundle group is the furnace outlet, it is required to cut the ends of the straight fins on the side closest to the furnace space of the first row of symmetrical forked straight finned tubes and the first row of symmetrical double-wing longitudinal straight finned tubes to reduce their fin extension length.

[0012] The fully premixed water-cooled burner can be planar, curved, ellipsoidal, ellipsoidal, or a combination of planar types. The front water-cooled wall is adapted to fit the shape of the combustion surface and acts as the water-cooled tube bundle of the burner. Alternatively, multiple modular burners can be combined to correspond to a large-capacity boiler body. The fully premixed water-cooled burners are arranged side by side on the front water-cooled wall along the axis of the boiler drum, and the flue gas outlet is located at the center of the rear water-cooled wall at the tail of the boiler.

[0013] A diffusion burner is used instead of a fully premixed water-cooled burner. A partition wall water-cooled wall is installed, and the front wall water-cooled wall is replaced by the right wall water-cooled wall of the diffusion burner, and the rear wall water-cooled wall is replaced by the left wall water-cooled wall of the diffusion burner. One of the side wall water-cooled walls serves as the front wall water-cooled wall and the rear wall water-cooled wall of the diffusion burner. The partition wall water-cooled wall, the front wall water-cooled wall, the rear wall water-cooled wall, and the right wall water-cooled wall of the diffusion burner surround and form the furnace space. The flue gas outlet is located at the center of the left wall water-cooled wall of the diffusion burner at the tail of the boiler.

[0014] The boiler body is symmetrically equipped with two sets of front bare tube bundles, straight finned tube irregular combination tube bundle groups, rear wall water-cooled wall, side wall water-cooled wall, water-cooled wall header and partition wall water-cooled wall. It also has two furnace spaces. Two diffusion burners are symmetrically arranged on the front wall water-cooled wall of the two furnace spaces. The flue gas outlet is located on the outermost tube bank on the same side of the diffusion burner, between the upper and lower drums of the boiler. It has two independent upper and lower drums, and the steam outlets of the two upper drums are connected.

[0015] The fully premixed water-cooled burner adopts a combination of multiple modular burners corresponding to a large-capacity boiler body. The boiler body is symmetrically arranged with two sets of front bare tube bundles, straight finned tube irregular combination tube bundle groups, front wall water-cooled wall, side wall water-cooled walls and water-cooled wall headers, and includes two furnace spaces. The fully premixed water-cooled burners are symmetrically arranged side by side along the boiler drum axis on the front wall water-cooled wall of the two furnace spaces of the boiler. The flue gas outlet is located on the outermost tube bank on one side between the upper and lower drums on the left and right sides of the boiler. When the boiler capacity is further increased, a row of partition water-cooled wall tube banks is set between the two sets of straight finned tube irregular combination tube bundle groups on the left and right symmetrical center plane of the boiler. The flue gas outlet is symmetrically located on the outermost tube bank between the upper and lower drums on the left and right sides of the boiler. The boiler body and burner have a bilaterally symmetrical combination structure with two sets of independent upper and lower drums, and the steam outlets of the two upper drums are connected.

[0016] The tail end of the boiler body is equipped with an economizer with the same structure as the straight finned tube irregular combination tube bundle group. The boiler feedwater first enters the economizer and is composed of the straight finned tube irregular combination tube bundle group connecting the upper header and the lower header of the economizer. Baffles are installed inside both the upper and lower headers of the economizer. An opening for steam communication is set at the upper part of the baffle inside the upper header of the economizer. After being heated by the economizer, the boiler feedwater is sent to the upper drum of the boiler body and enters the water circulation formed by the upper and lower drums of the boiler body.

[0017] When setting up two sets of upper and lower boiler drums, water pipe bundles of the same diameter are used to connect the upper and lower boiler drums. The bending angle and bending radius of all water pipe bundles connected between the upper and lower boiler drums are the same as those of the bends connecting the upper and lower boiler drums. An independent steam space boiler drum is arranged above the two upper boiler drums. The independent steam space boiler drum is connected to the two water-filled upper boiler drums below it, so that the steam generated by the two upper boiler drums is separated in the top-mounted independent steam space boiler drum.

[0018] As a gas-fired hot water boiler, both the upper and lower drums are filled with water. The boiler return water first enters the economizer, and the water heated by the economizer is distributed to the longitudinally segmented area in the lower drum corresponding to the low flue gas temperature tube bundle. Then, the water is forced to flow between the longitudinal baffles and the corresponding medium and high flue gas temperature tube bundles inside the upper and lower drums and is continuously heated. Finally, it is sent from the upper drum to the side wall water-cooled wall and front wall water-cooled wall in the boiler furnace for forced water circulation heating. Finally, the water is continuously heated to hot water at the rated pressure and temperature and led out from the outlet header.

[0019] As a negative pressure and micro-pressure phase change boiler, all water tube bundles are welded to the cylindrical body. Water evaporates from the lower half-circumference of the upper drum to generate steam, which rises and interacts with the phase change straight finned tube irregular combination bundle group arranged horizontally in the independent steam space of the boiler drum through a multi-mechanism enhanced condensation heat exchange from top to bottom. The condensate enters the water space of the upper drum and waits to be heated before circulating and evaporating. The deionized water in the upper and lower drums is repeatedly heated, evaporated and condensed. Low-temperature return water enters the cooling steam space through the steam from one end of the phase change straight finned tube irregular combination bundle group inlet header. The low-temperature return water is heated into hot water and led out from the other end outlet header.

[0020] The phase change straight finned tube irregular combination tube bundle group includes symmetrical double-wing longitudinal straight finned tubes and double-wing offset longitudinal straight finned tubes. The symmetrical double-wing longitudinal straight finned tubes and double-wing offset longitudinal straight finned tubes are arranged alternately in the same row and in the same column. The double-wing offset longitudinal straight finned tube includes a light tube and longitudinal straight fins. The longitudinal straight fins are arranged radially on one side away from the center plane of the light tube.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] This invention applies a combination of airfoil-finned tubes and longitudinal finned tubes to the convective heat transfer tube bundles of a water-tube boiler. Through the ingenious arrangement of the flue gas flow channels outside the water tubes, a multi-mechanism heat transfer enhancement method is achieved, organically combining mechanisms such as slot laminar flow heat transfer enhancement, jet flow heat transfer enhancement, and turbulent flow heat transfer enhancement. This allows the boiler flue gas to pass through a minimal number of convective tube bundles, resulting in a significantly reduced temperature. This substantially reduces the steel consumption and welding workload required for boiler manufacturing, thereby lowering boiler manufacturing costs and carbon emissions during boiler production. The multi-mechanism enhanced heat transfer tube bundles do not significantly alter the original boiler structure, providing excellent burner adaptability for the boiler. The design is adaptable to traditional diffusion burners, facilitating structural modifications of conventional boilers. Overall, it provides a novel energy-saving device structure employing a multi-mechanism enhanced heat exchange tube bundle, improving the overall heat transfer coefficient and reducing the energy-saving device's size and manufacturing cost. By using a single furnace wall water-cooled as the water-cooled tube bundle of the fully premixed water-cooled burner, the SHS gas boiler is organically combined with the fully premixed water-cooled burner, achieving fully premixed water-cooled combustion. This reduces combustion temperature and nitrogen oxide emissions, while also decreasing flame length, resulting in a smaller furnace volume and a more compact overall boiler structure. This further reduces steel consumption and welding workload required for boiler manufacturing.

[0023] Furthermore, the boiler body offers different modification structures for different usage scenarios, and can be used for various boiler types such as hot water boilers, steam boilers, and vacuum phase change boilers.

[0024] Furthermore, for large-capacity boiler bodies, a modular fully premixed water-cooled burner combination application solution is provided, which effectively solves the contradiction between the difficulty of scaling up fully premixed water-cooled burners and the advantages of water tube boiler bodies in the field of large-scale production, so that the advantages of both can be fully utilized. Attached Figure Description

[0025] Figure 1 This is a top cross-sectional view of a gas-fired boiler with a multi-mechanism coupling enhanced heat exchange system (SHS) using straight finned tubes and irregularly shaped combinations, according to the present invention.

[0026] Figure 2 This is a right-side cross-sectional view of a gas-fired boiler with a straight finned tube irregular combination and multi-mechanism coupling to enhance heat exchange, according to the present invention.

[0027] Figure 3a This is a schematic diagram of the straight finned tube irregular combination tube bundle structure in this invention. Figure 3b This is a schematic diagram of the multi-mechanism coupling enhanced heat transfer unit of the straight finned tube irregular combination tube bundle group in this invention.

[0028] Figure 4a This is a schematic diagram of the symmetrical forked straight finned tube structure in this invention. Figure 4b This is a schematic diagram of the symmetrical double-wing longitudinal straight finned tube structure in this invention.

[0029] Figure 5 This is a schematic diagram of a single-sided multi-module fully premixed water-cooled burner combined with a boiler body according to the present invention.

[0030] Figure 6 This is a schematic diagram of a single-sided diffusion burner combined with a boiler body according to the present invention.

[0031] Figure 7 This is a schematic diagram of a combination of a dual-sided multi-module fully premixed water-cooled burner and the boiler body according to the present invention.

[0032] Figure 8 This is a schematic diagram of a combination of a bilateral diffusion burner and a boiler body according to the present invention.

[0033] Figure 9 This is a schematic diagram of a multi-mechanism coupled enhanced heat exchanger energy-saving device according to the present invention.

[0034] Figure 10 This is a right-side cross-sectional view of a gas-fired steam boiler with a straight finned tube irregular combination and multi-mechanism coupling to enhance heat exchange according to the present invention.

[0035] Figure 11 This is a right-side cross-sectional view of a gas-fired hot water boiler with a straight finned tube irregular combination and multi-mechanism coupling to enhance heat exchange according to the present invention.

[0036] Figure 12This is a partial right-side cross-sectional view of a SHS gas-fired vacuum phase change boiler with a multi-mechanism coupling and enhanced heat transfer of straight finned tubes and irregular shapes, according to the present invention.

[0037] In the attached diagram, 1-fully premixed water-cooled burner, 21-diffusion burner, 2-upper drum, 3-lower drum, 4-front bare tube bundle, 5-straight finned tube irregular combination bundle group, 6-front water-cooled wall, 61-right side water-cooled wall of diffusion burner, 7-rear water-cooled wall, 71-left side water-cooled wall of diffusion burner, 8-both side water-cooled walls, 81-front water-cooled wall of diffusion burner, 82-rear water-cooled wall of diffusion burner. 9-Water-cooled wall header, 10-Furnace space, 11-Flue gas outlet, 12-Symmetrical forked straight finned tube, 121-Smooth tube, 122-Longitudinal straight fin, 13-Symmetrical double-wing longitudinal straight finned tube, 14-Water-cooled partition wall, 15-Water-cooled partition wall tube bank, 161-Energy saver upper header, 162-Energy saver lower header, 163-Baffle plate, 17-Phase change straight finned tube irregular combination tube bundle group, 18-Independent steam space boiler drum. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings.

[0039] In this invention, "front" and "rear" refer to the relative positions of the boiler body, with the burner located in the front and the burner outlet facing the rear.

[0040] refer to Figures 1 to 2A multi-mechanism enhanced heat exchange SHS gas-fired boiler includes a fully premixed water-cooled burner 1, an upper drum 2, a lower drum 3, a front bare tube bundle 4, a straight finned tube irregular combination bundle group 5, a front wall water-cooled wall 6, two side wall water-cooled walls 8, a furnace space 10, and a flue gas outlet 11. The fully premixed water-cooled burner 1 is mounted on the front wall water-cooled wall 6 to act as a water-cooled combustion tube bank to form a water-cooled burner head. The front wall water-cooled wall 6 is located on the fully premixed water-cooled burner 1. The outlet connection point is a bare tube bundle, while the remaining positions are membrane water-cooled wall structures welded from bare tubes and flat steel. Two sets of water-cooled wall headers 9 are installed on the upper and lower sides of the water-cooled walls 8 near the furnace space 10 at both ends of the upper drum 2 and lower drum 3, respectively, and are connected vertically to the side wall water-cooled walls. That is, the water-cooled wall headers 9 include an upper header and a lower header, which are respectively connected to the upper and lower ends of the side wall water-cooled walls 8. The front wall water-cooled wall 6, the front bare tube bundle 4, and... The furnace space 10 is formed by the water-cooled walls 8 on both sides. One or two rows of bare tube bundles and three rows of straight finned tube irregular combination bundles 5 are arranged sequentially along the flue gas flow direction at the outlet of the furnace space 10. The bare tube bundles, straight finned tube irregular combination bundles 5 and the upper and lower ends of the front wall water-cooled wall 6 are respectively connected to the upper drum 2 and the lower drum 3. The boiler body flue gas outlet 11 is set at the center of the rear wall water-cooled wall 7 at the tail of the boiler body. In this invention, an energy saver is arranged at the tail of the SHS boiler body. The energy saver is equipped with straight finned tube irregular combination bundles 5. The energy saver is connected to the flue gas outlet 11. The boiler feedwater first enters the water treatment device, then enters the deaerator for deoxygenation, and then enters the energy saver. After being heated by the energy saver, the boiler feedwater is sent to the upper drum 2 and thus enters the water circulation loop formed by the upper drum 2 and the lower drum 3. The energy saver can effectively reduce the exhaust gas temperature of the boiler body and improve the overall thermal efficiency of the boiler.

[0041] refer to Figure 3a The straight finned tube bundle group 5 is formed by alternating arrangements of two types of finned tubes with the same diameter: symmetrical forked straight finned tubes 12 and symmetrical double-wing longitudinal straight finned tubes 13. Both types of finned tubes have fins only on the vertical tube sections. Membrane wall structures are used at bends and when connecting to the boiler drum. The fins of two adjacent symmetrical forked straight finned tubes 12 surround the symmetrical double-wing longitudinal straight finned tube 13 between them, forming a flue gas flow channel for enhanced convective heat transfer through slit laminar flow between the two tubes. The tubes in the same row and the adjacent row that are adjacent to the symmetrical double-wing longitudinal straight finned tubes 13 are all symmetrical forked straight finned tubes 12.

[0042] refer to Figure 3bEach row of tubes has symmetrical forked straight finned tubes 12 corresponding to the symmetrical double-wing longitudinal straight finned tubes 13 of the adjacent tube rows in the front-back direction, forming a staggered arrangement. Several rows of tube bundles constitute a group of irregularly shaped combined tube bundles of straight finned tubes. Between every four adjacent tube bundles, a hexagonal cross-section is formed, consisting of two forked straight fin segments AB and DE, two longitudinal straight fin segments BC and EF, and two bare tube arc segments CD and FA. During dynamic operation (the longitudinal straight fins will elongate and stick to the bare tube wall due to linear thermal expansion, and gaps will appear due to cooling contraction when the boiler stops running), this hexagonal cross-section has only one flue gas inlet and one flue gas outlet. The flue gas exits through the gap formed by the AB forked straight fin segment and the adjacent bare tube segment. After completing the slot laminar flow enhanced heat transfer, the flue gas flows out and undergoes slot impingement jet enhanced heat transfer on the straight section BC of the longitudinal straight fin. Subsequently, slot impingement jet enhanced heat transfer is performed on part of the bare tube arc section CD. Then, the flue gas disperses and diffuses to the other walls of the hexagonal cross section for turbulent enhanced heat transfer, so that the back bare tube arc section FA, which is usually not swept by the flue gas, can also undergo convective enhanced heat transfer. Finally, the flue gas gathers at point E and re-enters the fin slot to complete the next round of slot laminar flow enhanced heat transfer process. The entire hexagonal cross section plane develops into a hexagonal column along the four tube bundle axes, thus forming a hexagonal column with multi-mechanism coupled convective enhanced heat transfer of slot laminar flow enhancement, slot impingement jet enhancement, and spatial turbulence enhancement.

[0043] refer to Figure 4a and Figure 4b The symmetrical forked straight finned tube 12 is composed of four longitudinal straight fins 122 symmetrically arranged in a forked shape on both sides of the bare tube 121. The symmetrical double-wing longitudinal straight finned tube 13 is composed of two longitudinal straight fins 122 symmetrically attached to both sides of the bare tube 121 in a wing-shaped arrangement. The thickness of a single longitudinal straight fin is the same as or slightly larger than the wall thickness of the bare tube 121. The symmetrical forked straight finned tube 12 and the symmetrical double-wing longitudinal straight finned tube 13 can be formed by integral rolling or forging into finned tubes or by fully welding longitudinal flat steel onto the bare tube.

[0044] refer to Figure 3a In general, a front bare tube bundle 4 is arranged in front of the straight finned tube irregular combination tube bundle group 5 to reduce the flue gas temperature entering the straight finned tube irregular combination tube bundle group 5. However, when the boiler structure is required to be exceptionally compact, the front bare tube bundle 4 can be directly removed. In this case, the front side of the straight finned tube irregular combination tube bundle group 5 is the furnace outlet. Then, the straight fin ends of the first row of symmetrical forked straight finned tubes 12 and the first row of symmetrical double-wing longitudinal straight finned tubes 13 near the furnace space 10 are cut to reduce their fin extension length. This is to prevent the fin ends extending into the furnace from overheating due to flame and high-temperature flue gas radiation, which would cause local material deterioration and cracking.

[0045] The fully premixed water-cooled burner 1 can be a planar type, curved type, ellipsoidal type, ellipsoidal type or a combination of planar types. In this case, the front wall water-cooled wall 6 is adapted to fit the shape of the combustion surface and acts as the burner water-cooled tube bundle.

[0046] refer to Figure 5 Alternatively, multiple modular burners can be combined to correspond to a large-capacity boiler body. The fully premixed water-cooled burners 1 are arranged side by side on the front water-cooled wall 6 along the axis of the boiler drum, and the flue gas outlet 11 is located at the center of the rear water-cooled wall 7 at the tail of the boiler.

[0047] refer to Figure 6 The boiler body and burner combination scheme can also adopt a traditional diffusion burner 21 with a certain flame diameter and length to replace the fully premixed water-cooled burner 1. In this case, the original front wall water-cooled wall 6 becomes the right wall water-cooled wall 61 of the diffusion burner. One of the original two side wall water-cooled walls 8 is the front wall water-cooled wall 81 and the rear wall water-cooled wall 82 of the diffusion burner, which can be used to arrange the burners. The partition wall water-cooled wall 14, the front wall water-cooled wall 81, the rear wall water-cooled wall 82 and the right wall water-cooled wall 61 of the diffusion burner surround and form the furnace space 10. The flue gas outlet 11 is located at the center of the left wall water-cooled wall 71 of the diffusion burner at the tail of the boiler.

[0048] refer to Figure 7 The fully premixed water-cooled burner 1 can be a combination of multiple modular burners corresponding to a large-capacity boiler body. The boiler body is symmetrically arranged with two sets of front bare tube bundles 4, straight finned tube irregular combination tube bundle groups 5, front wall water-cooled wall 6, side wall water-cooled walls 8, and water-cooled wall headers 9, and includes two furnace spaces 10. The fully premixed water-cooled burners 1 are symmetrically arranged side by side along the boiler drum axis on the front wall water-cooled wall 6 of the two furnace spaces 10 of the boiler. The flue gas outlet 11 is located on the outermost tube bank on one side between the upper drum 2 and the lower drum 3 on the left and right sides of the boiler. When the boiler capacity is further increased, a row of partition water-cooled wall tube banks 15 is set between the two sets of straight finned tube irregular combination tube bundle groups 5 on the left and right symmetrical center plane of the boiler. At this time, the flue gas outlet 11 is symmetrically located on the outermost tube bank between the upper drum 2 and the lower drum 3 on the left and right sides of the boiler. The SHS gas boiler in the above combination scheme of the boiler body and burner with left and right sides being symmetrical can be composed of two SHS gas boilers with independent upper and lower drums, which are symmetrical on the left and right sides respectively. Then, the steam outlets of the two upper drums can be connected.

[0049] refer to Figure 8Alternatively, the boiler body and burner combination scheme can employ a diffusion burner 21. The boiler body is symmetrically arranged with two sets of front-mounted bare tube bundles 4, straight-finned tube irregular combination bundle groups 5, a rear wall water-cooled wall 7, two side wall water-cooled walls 8, water-cooled wall headers 9, and partition wall water-cooled walls 14. It also includes two furnace spaces 10. Two diffusion burners 21 are symmetrically arranged on the front wall water-cooled walls 6 of the two furnace spaces 10. The flue gas outlet 11 is located between the upper drum 2 and the lower drum 3 of the boiler, on the outermost row of tubes on the same side as the diffusion burner 21. In the above bilaterally symmetrical combination scheme of the boiler body and diffusion burner, the SHS gas boiler can be composed of two SHS gas boilers, each with an independent upper and lower drum, symmetrically arranged on the left and right sides. The steam outlets of the two upper drums are then connected.

[0050] refer to Figure 9 The tail end of the SHS gas boiler body is equipped with an economizer with the same structure as the straight finned tube irregular combination tube bundle group 5. The boiler feedwater first enters the economizer, which effectively reduces the flue gas temperature and improves the boiler thermal efficiency. The economizer is composed of the straight finned tube irregular combination tube bundle group 5 connecting the upper header 161 and the lower header 162 of the economizer. Baffles 163 are set inside the upper and lower headers. An opening for steam communication is set on the upper part of the baffles 163 inside the upper header of the economizer. After being heated by the economizer, the boiler feedwater is sent into the upper drum 2 of the boiler body and thus enters the water circulation formed by the upper and lower drums of the boiler body.

[0051] based on Figure 8 and Figure 9 The diagram shows a symmetrical combination of the boiler body and burner on both sides. (Reference) Figure 10 When an SHS gas boiler can be composed of two SHS gas boilers with independent upper and lower drums that are symmetrical on the left and right, the upper drum of the SHS boiler has a steam space requirement. The diameter of the upper drum 2 of the SHS boiler is always larger than the diameter of the lower drum 3. This results in different bending angles and bending radii of the water pipe bundles connecting the upper and lower drums and the bends connecting the upper and lower drums, which causes great inconvenience to the bending and welding processes. This invention selects the same drum diameter for the upper and lower drums of the SHS gas-fired boiler, which has independent upper and lower drums. All water pipe bundles connected between the upper and lower drums and the bending angles and radii of the bends connecting the upper and lower drums are the same, and the welding process is also the same, which greatly simplifies the manufacturing process. However, at this time, both the upper and lower drums of the SHS boiler are filled with water, and the upper drum 2 no longer has a steam space. Therefore, an independent steam space drum 18 needs to be arranged on top of the two upper drums 2 and connected to the two water-filled upper drums 2 below. This allows the steam generated by the left and right upper drums to be separated in the top drum. At this time, the top drum and the two SHS gas-fired boilers with independent upper drums 2 and lower drums 3 respectively form a water circulation. Water circulation calculations are performed as needed during operation.

[0052] refer to Figure 11 This invention is also applicable to SHS gas-fired hot water boilers. In this case, both the upper and lower drums of the SHS gas-fired hot water boiler are filled with water. The boiler return water first enters the economizer, which effectively reduces the flue gas temperature of the boiler body and improves the boiler thermal efficiency. Then, the water heated by the economizer is distributed to the longitudinally segmented area in the lower drum corresponding to the low flue gas temperature tube bundle. The water is then forced to flow and continuously heated between the longitudinal baffles and the corresponding medium and high flue gas temperature tube bundles inside the upper and lower drums. Finally, the water is sent from the upper drum to the water-cooled walls on both sides and the water-cooled wall in the boiler furnace for forced water circulation heating. Finally, the water is continuously heated to hot water at the rated pressure and temperature and then led out from the hot water outlet header for hot water supply.

[0053] refer to Figure 12 The SHS gas-fired hot water boiler is also suitable for negative pressure vacuum and micro-pressure phase change boilers. All water tube bundles of the negative pressure vacuum and micro-pressure phase change boiler are welded to the cylindrical body. At this time, the heated and evaporating tube bundles evaporate from the lower half of the upper drum to generate steam that rises upward. Similar to the phase change straight finned tube irregular combination tube bundle group 5 arranged horizontally in the steam space, the phase change straight finned tube irregular combination tube bundle group 17 performs multi-mechanism enhanced condensation heat exchange from top to bottom. The condensate enters the water space of the upper drum and waits to be heated and then circulates for evaporation. In this way, the deionized water in the upper and lower drums is repeatedly heated, evaporated and condensed, which will not form scale and reduce carbon emission intensity. Low temperature return water enters the cooling steam space from one end of the phase change straight finned tube irregular combination tube bundle group 17 through the inlet header and is heated into hot water and led out from the other end outlet header for hot water supply.

[0054] The phase-change straight-finned tube irregular combination bundle group 17 includes symmetrical double-wing longitudinal straight-finned tubes 13 and double-wing offset longitudinal straight-finned tubes. The symmetrical double-wing longitudinal straight-finned tubes 13 and double-wing offset longitudinal straight-finned tubes 13 and 13 are arranged alternately in the same row and in the same column. The symmetrical double-wing longitudinal straight-finned tubes 13 and double-wing offset longitudinal straight-finned tubes 13 and 13 are arranged alternately in adjacent rows. The symmetrical double-wing longitudinal straight-finned tubes 13 and double-wing offset longitudinal straight-finned tubes 13 are directly opposite each other. The double-wing offset longitudinal straight-finned tube includes a light tube and longitudinal straight fins. The longitudinal straight fins are arranged radially on one side away from the center plane of the light tube. The longitudinal straight fins 122 of the symmetrical double-wing longitudinal straight-finned tubes 13 in the row adjacent to the double-wing offset longitudinal straight-finned tube are located between the two longitudinal straight fins on the double-wing offset longitudinal straight-finned tube.

Claims

1. A SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange, characterized in that, The application relates to a boiler, which comprises a full premixed water-cooled burner (1), an upper drum (2), a lower drum (3), a front light pipe bundle (4), a straight fin pipe special-shaped combined pipe bundle group (5), a front wall water-cooled wall (6), a side wall water-cooled wall (8), and the full premixed water-cooled burner (1) is arranged on the front wall water-cooled wall (6) to serve as a water-cooled combustion pipe row to form a water-cooled combustion head; the front wall water-cooled wall (6) is connected with the light pipe bundle at the outlet joint position of the full premixed water-cooled burner (1) and is connected with the membrane water-cooled wall structure formed by welding the light pipe and flat steel at the other positions; the upper drum (2) and the lower drum (3) are arranged on the side wall water-cooled wall (8) in a vertical mode at the left and right ends, and are connected with the side wall water-cooled wall (8) in a vertical mode through two groups of water-cooled wall headers (9) arranged on the upper and lower sides; the front wall water-cooled wall (6), the front light pipe bundle (4) and the side wall water-cooled wall (8) surround a furnace space (10); the light pipe bundle and a plurality of rows of straight fin pipe special-shaped combined pipe bundle groups (5) are arranged in the furnace space (10) in sequence along the flue gas flow direction; the upper and lower ends of the light pipe bundle, the straight fin pipe special-shaped combined pipe bundle group (5) and the front wall water-cooled wall (6) are connected with the upper drum (2) and the lower drum (3) respectively; a flue gas outlet (11) is connected with the furnace space (10) and an economizer; the straight fin pipe special-shaped combined pipe bundle group (5) is arranged in the economizer; the boiler feed water is heated in the economizer and then is sent into the upper drum to enter a water circulation loop formed by the upper drum and the lower drum; the full premixed water-cooled burner (1) is in a planar type, a curved surface type or an ellipsoidal surface type; the front wall water-cooled wall (6) is matched with the combustion surface shape and serves as a water-cooled pipe bundle of the burner; the straight fin pipe special-shaped combined pipe bundle group (5) is formed by the symmetrical fork-shaped straight fin pipe (12) and the symmetrical double-wing-shaped longitudinal straight fin pipe (13) arranged in a spaced mode; the same row and the adjacent row of the symmetrical double-wing-shaped longitudinal straight fin pipe (13) are all the symmetrical fork-shaped straight fin pipe (12); the two kinds of fin pipes are provided with fins only on the vertical pipe sections, and the membrane wall structure is adopted in the elbow and the connecting drum part; the fins of the two symmetrical fork-shaped straight fin pipes (12) embrace the symmetrical double-wing-shaped longitudinal straight fin pipe (13) between the two symmetrical fork-shaped straight fin pipes (12) in a left and right mode, and a gap flow strengthening convection heat exchange flue gas flow channel is formed between the symmetrical fork-shaped straight fin pipe (12) and the symmetrical double-wing-shaped longitudinal straight fin pipe (13); in the straight fin pipe special-shaped combined pipe bundle group (5), the symmetrical fork-shaped straight fin pipe (12) of each pipe row corresponds to the symmetrical double-wing-shaped longitudinal straight fin pipe (13) of the adjacent pipe row in the front and back directions, and the straight fin pipe special-shaped combined pipe bundle group is formed by the plurality of pipe rows; four pipe bundles are arranged in each adjacent four pipe bundles to form a hexagonal section composed of two fork-shaped straight fin sections AB, DE, two longitudinal straight fin straight sections BC, EF and two light pipe arc sections CD, FA; the hexagonal section has only one flue gas inlet and one flue gas outlet in the dynamic operation, and the whole hexagonal section plane develops into a hexagonal columnar body along the four pipe bundle axial directions.

2. A SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 1, characterized in that, The symmetric fork-shaped straight fin tube (12) is composed of four symmetric fork-shaped longitudinal straight fins (122) on both sides of the light tube (121), and the symmetric double-wing-shaped longitudinal straight fin tube (13) is composed of two symmetric wing-shaped longitudinal straight fins (122) on both sides of the light tube (121). The thickness of a single longitudinal straight fin is not less than the wall thickness of the light tube (121). The symmetric fork-shaped straight fin tube (12) and the symmetric double-wing-shaped longitudinal straight fin tube (13) are respectively formed by integral rolling, forging forming into finned tubes or by full penetration welding of longitudinal flat steel on the light tube.

3. The SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 1, characterized in that, The front light tube bundle (4) is arranged in front of the straight fin tube special-shaped combined tube bundle group (5) to reduce the flue gas temperature entering the straight fin tube special-shaped combined tube bundle group (5).

4. The SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 1, characterized in that, The front side of the straight fin tube special-shaped combined tube bundle group (5) is the furnace outlet. The straight fin ends of the first row of symmetric fork-shaped straight fin tubes (12) and the first row of symmetric double-wing-shaped longitudinal straight fin tubes (13) near the furnace space (10) are subjected to cutting processing to reduce the fin extension length.

5. A SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 1, characterized in that, A plurality of modular burners are used to correspond to the combined form of a large-capacity boiler body. The full premix water-cooled burners (1) are arranged in parallel on the front wall water-cooled wall (6) along the axis direction of the drum. The flue gas outlet (11) is arranged at the center position of the rear wall water-cooled wall (7) at the tail of the boiler.

6. A SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 1, characterized in that, The diffusion burners (21) are used to replace the full premix water-cooled burners (1). The front wall water-cooled wall (6) is changed into the diffusion burner right side wall water-cooled wall (61). The rear wall water-cooled wall (7) is changed into the diffusion burner left side wall water-cooled wall (71). The diffusion burner front wall water-cooled wall (81) or the diffusion burner rear wall water-cooled wall (82) is used as the side wall water-cooled wall (8) for arranging the diffusion burners. The diffusion burner front wall water-cooled wall (81), the diffusion burner rear wall water-cooled wall (82), the diffusion burner right side wall water-cooled wall (61) and the diffusion burner left side wall water-cooled wall (71) form the furnace space (10). The flue gas outlet (11) is arranged at the center position of the diffusion burner left side wall water-cooled wall (71) at the tail of the boiler.

7. A SHS gas boiler with combined poly-mechanism of straight fin tube profile according to claim 6, characterized in that, Two groups of front light tube bundles (4), straight fin tube special-shaped combined tube bundle groups (5), rear wall water-cooled walls (7), side wall water-cooled walls (8), water-cooled wall headers (9) and partition wall water-cooled walls (14) are symmetrically arranged in front of and behind the boiler body. Two furnace spaces (10) are arranged. Two diffusion burners (21) are symmetrically arranged on the front wall water-cooled wall (6) of the two furnace spaces (10). The flue gas outlet (11) is arranged on the outermost row of tubes on the same side of the diffusion burners (21) and between the upper drum (2) and the lower drum (3) of the boiler. Two sets of independent upper drums and lower drums are arranged, and the steam outlets of the two upper drums are connected.

8. A SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 1, characterized in that, The full premix water-cooled burner (1) adopts a combination form of multiple modular burners corresponding to a large-capacity boiler body, two groups of front light pipe bundles (4), straight fin tube special-shaped combined tube bundle groups (5), front wall water-cooled walls (6), two side wall water-cooled walls (8) and water-cooled wall headers (9) are symmetrically arranged on the front wall water-cooled walls (6) of the two furnace spaces (10) of the boiler along the axis direction of the drum, and the full premix water-cooled burner (1) is symmetrically arranged on the front wall water-cooled walls (6) of the two furnace spaces (10) of the boiler along the axis direction of the drum, and the smoke outlet (11) is arranged on the outermost tube row of one side between the upper drum (2) and the lower drum (3) on the left and right sides of the boiler; when the capacity of the boiler is further improved, a row of partition water-cooled wall tube rows (15) is arranged between the front and rear two groups of straight fin tube special-shaped combined tube bundle groups (5) on the central plane symmetric to the left and right of the boiler, and the smoke outlet (11) is symmetrically arranged on the outermost tube row between the upper drum (2) and the lower drum (3) on the left and right sides of the boiler; the combination structure of the boiler body and the burner is bilaterally symmetric, and two sets of independent upper drums and lower drums are arranged symmetrically, and the steam outlets of the two upper drums are connected.

9. The SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 1, characterized in that, The tail of the boiler body is arranged with an economizer having the same structure as the straight fin tube special-shaped combined tube bundle group (5), the boiler feed water first enters the economizer, the straight fin tube special-shaped combined tube bundle group (5) is connected with the upper header (161) and the lower header (162) of the economizer to form a group, baffles (163) are arranged in the upper header (161) and the lower header (162) of the economizer, and openings for communicating steam are arranged on the upper part of the baffle (163) in the upper header (161) of the economizer, the boiler feed water is heated by the economizer and then sent into the upper drum (2) of the boiler body, and enters the water circulation formed by the upper and lower drums of the boiler body.

10. The SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 8 or 9, characterized in that, When two sets of upper drums (2) and lower drums (3) are arranged, water tube bundles of the same diameter are arranged to connect the upper drum (2) and the lower drum, the bending angle and bending radius of the bending pipe section connected between the upper drum (2) and the lower drum (3) and the water tube bundles connected to the upper drum (2) and the lower drum (3) are the same, an independent steam space drum (18) is arranged above the two upper drums (2), the independent steam space drum (18) is connected with the two full water upper drums (2) below, so that the steam generated by the two upper drums (2) is separated in the top independent steam space drum (18).

11. A SHS gas boiler with combined poly-mechanism of straight fin tube profile according to claim 1, characterized in that, As a gas hot water boiler, the upper drum (2) and the lower drum (3) are full of water, the boiler return water first enters the economizer, the water heated by the economizer is distributed to the corresponding longitudinal division area of the low smoke temperature tube bundle in the lower drum (3), then the water is forced to flow between the longitudinal baffles in the upper drum (2) and the lower drum (3) and the corresponding medium and high smoke temperature tube bundle and is continuously heated, finally the water is sent from the upper drum (2) to the side wall water-cooled wall and the front wall water-cooled wall in the boiler furnace for forced water circulation heating, and finally the water is continuously heated into hot water of rated pressure and temperature and is led out from the outlet header.

12. A SHS gas boiler with combined poly-mechanism of straight fin tube profile according to claim 9, characterized in that, As a negative pressure and micro pressure phase change boiler, all water tube bundles are welded with the cylinder, water evaporates from the upper half circumference of the upper drum to generate steam rising up, and the phase change straight fin tube special-shaped combined bundle group (17) horizontally arranged in the independent steam space drum (18) carries out multi-mechanism enhanced condensation heat exchange from top to bottom, and the condensed water enters the water space of the upper drum to wait for heating and then circulating evaporation; the low temperature return water enters the steam cooling space through the steam from the one end inlet header of the phase change straight fin tube special-shaped combined bundle group (17), and the low temperature return water is heated into hot water from the other end outlet header.

13. The SHS gas boiler with straight fin tube special-shaped combined multi-mechanism coupled enhanced heat exchange according to claim 11 or 12, characterized in that, The phase change straight fin tube special-shaped combined bundle group (17) comprises symmetrical double-wing longitudinal straight fin tubes (13) and double-wing offset longitudinal straight fin tubes, the symmetrical double-wing longitudinal straight fin tubes (13) and the double-wing offset longitudinal straight fin tubes are arranged at intervals in the same row, the symmetrical double-wing longitudinal straight fin tubes (13) and the double-wing offset longitudinal straight fin tubes are arranged at intervals in the same column, the double-wing offset longitudinal straight fin tube comprises a light tube and a longitudinal straight fin, and the longitudinal straight fin is arranged on one side deviated from the center surface of the light tube in a radial manner.

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