A cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchange compact hydrogen wall-mounted boiler

Abstract

The present invention discloses a cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchanger compact hydrogen wall-mounted boiler, which includes a burner, a heat exchanger, an expansion tank and a flue; the burner, the heat exchanger, the expansion tank and the flue are arranged in a cylindrical shape and coaxially; a heat exchanger inner cylinder is arranged at the lower part of the heat exchanger, heat exchanger fins are arranged circumferentially on the outer side of the heat exchanger inner cylinder, a containing space is formed by the heat exchanger fins at the top of the heat exchanger inner cylinder, the burner is arranged in the containing space, and a combustion chamber is formed between the outer side of the lower part of the burner and the inner side of the upper part of the heat exchanger; the expansion tank is located at the center inside the heat exchanger inner cylinder, and the flue is located at the bottom of the heat exchanger; the top of the heat exchanger is sealed, the bottom is communicated with the flue, and a heat exchanger water channel is arranged on the side surface of the heat exchanger; a burner with uniform combustion, low NO<subgt;x< / subgt; emission and strong anti-flashback performance is designed by combining the premixed water-cooled combustion technology and the cylindrical central air intake method; the compactness and beauty of the wall-mounted boiler are ensured by combining the extrusion aluminum fin enhanced heat transfer and the built-in expansion water tank method, and the safety is ensured by combining the material selection and the perfect monitoring and control equipment.

Description

Technical Field

[0001] The present invention belongs to the field of design of high-efficiency energy-saving and environment-friendly compact burners and heat exchangers, and particularly relates to a cylindrical premixed water-cooled combustion extruded aluminum fin heat exchange compact hydrogen wall-mounted boiler. Background Art

[0002] Hydrogen is a globally recognized zero-pollution energy source and an important direction for the development of future clean energy. Currently, the main distributed heating equipment in the world is gas wall-mounted boilers, which use natural gas as the energy source and produce a large amount of carbon emissions during combustion. Against this background, hydrogen is expected to replace natural gas as a new heating gas source. Compared with natural gas, hydrogen has a high flame temperature, high thermal NO x emission; low density and volumetric calorific value, low heat load; fast flame propagation speed, more prone to flashback; wide explosion limit range, more stringent control requirements; prone to hydrogen embrittlement phenomenon, strict requirements for materials. Currently, foreign countries have successfully developed hydrogen energy wall-mounted boilers and built hydrogen energy demonstration communities, while domestic ones still remain in the stage of improving efficiency and reducing emissions of fully premixed condensing gas wall-mounted boilers. There is an urgent need to develop a new type of low-nitrogen combustion enhanced heat transfer compact hydrogen-fired wall-mounted boiler to solve the problems of high NO x emission, low heat load and safety when hydrogen is used as the gas source of domestic wall-mounted boilers, and provide a theoretical basis and design idea for the development of domestic hydrogen-fired wall-mounted boilers.

[0003] Currently, the advanced gas wall-mounted boilers on the market mainly adopt the fully premixed combustion method, using metal fiber, ceramic fiber or stainless steel metal cylinder as the burner, with uniform combustion and short flame. However, in order to prevent the combustion chamber temperature from being too high and thus generating a large amount of NO x emission and burning out the burner head, a high excess air coefficient is usually adopted, which reduces the condensation rate and thermal efficiency. If the gas source is changed from natural gas to hydrogen, the combustion chamber temperature will be higher, and the existing fully premixed burners will not be able to meet the requirements. Fully premixed water-cooled combustion is a new combustion technology. By adding a water-cooled structure to the fully premixed burner to cool the flame root temperature, the combustion chamber temperature and NO x emission are reduced. Moreover, with the reduction of the flame root temperature, the flame propagation speed decreases and the flashback risk is reduced. Therefore, the fully premixed water-cooled combustion technology is an effective means to solve the problems of high hydrogen combustion temperature and easy flashback. Due to the complexity of the structure and more stringent control requirements, currently there are only wall-mounted boilers using atmospheric water-cooled combustion technology on the market, and the fully premixed water-cooled combustion technology is rarely applied in wall-mounted boilers.

[0004] At present, the advanced gas wall-mounted boilers on the market mainly adopt the condensing heat exchange method, with cast aluminum silicon or stainless steel as the heat exchanger material. The cast aluminum silicon wall-mounted boiler has a high heat exchange efficiency, a compact structure, and strong corrosion resistance, but the molds and materials are expensive; the stainless steel wall-mounted boiler is inexpensive, has a low equipment investment cost, and a large market share, but has a low heat exchange efficiency, a thin pipe wall, poor corrosion resistance, is prone to stress corrosion cracking, and has a short lifespan. China's extrusion aluminum process is mature, and the length of the heat exchanger can be arbitrarily cut to meet different power requirements. It has a simple structure, a low price, a high heat exchange efficiency, and strong corrosion resistance, making it an ideal process for manufacturing natural gas and hydrogen wall-mounted boilers.

[0005] In addition, the burners and heat exchangers of wall-mounted boilers on the market are mostly rectangular, and the air intake method of one-side air intake or middle air intake and distribution to both sides will inevitably lead to uneven combustion heat exchange or excessive resistance, resulting in problems such as low efficiency, unstable combustion, large gas consumption, and high pollutant emissions; the few cylindrical center air intake wall-mounted boilers are difficult to achieve compactness due to the large volume occupied by the cylinder and the space occupied by accessories such as expansion tanks in the wall-mounted boiler, and they are neither beautiful nor practical. Summary of the Invention

[0006] In order to solve the problems of high NO x emissions, low heat load, and safety issues when hydrogen is used as the gas source of a household wall-mounted boiler, based on the design concept of an efficient, energy-saving, and compact wall-mounted boiler, the present invention provides a cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchange compact hydrogen wall-mounted boiler. Combining the premixed water-cooled combustion technology and the cylindrical center air intake method, a hydrogen burner with uniform combustion, low NO x emissions, and strong anti-backfire performance is designed; the extrusion aluminum process and narrow-gap fins are used to improve the heat exchange efficiency, and the expansion tank is placed inside the wall-mounted boiler to reduce the overall space of the wall-mounted boiler, adapting to the characteristics of low heat load of hydrogen and ensuring compactness and beauty; at the same time, the selection of materials, perfect detection equipment, and safety devices ensure the safety of the hydrogen-burning wall-mounted boiler.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchange compact hydrogen wall-mounted boiler, including a burner, a heat exchanger, an expansion tank, and a flue; the burner, the heat exchanger, the expansion tank, and the flue are cylindrical and arranged coaxially, forming a center air intake hydrogen-burning wall-mounted boiler structure with an overall cylindrical shape; a heat exchanger inner cylinder is provided at the lower part of the heat exchanger, heat exchanger fins are arranged circumferentially on the outer side of the heat exchanger inner cylinder, a receiving space is formed between the top of the heat exchanger inner cylinder and the heat exchanger fins, the burner is arranged in the receiving space, and a combustion chamber is formed between the outer side of the lower part of the burner and the inner side of the upper part of the heat exchanger; the expansion tank is located at the center inside the heat exchanger inner cylinder, and the flue is located at the bottom of the heat exchanger; the top of the heat exchanger is sealed, the bottom is communicated with the flue, and a heat exchanger water channel is provided on the side of the heat exchanger; the burner adopts a premixed water-cooled burner.

[0008] The burner includes a hydrogen gas distribution pipe, an air distribution chamber, a mixing chamber, a burner water chamber, an ignition pin, a burner water inlet, a burner water outlet, and a burner cover plate; the hydrogen gas distribution pipe extends into the center of the burner, and hydrogen injection holes are provided in the lower part of the hydrogen gas distribution pipe; the burner water chamber includes an upper burner water chamber, a lower burner water chamber, and burner water chamber water-cooling pipes connecting the two. The burner water chamber water-cooling pipes are arranged along the circumference of the burner to form an annular space between the upper part of the hydrogen gas distribution pipe and the upper burner water chamber, and the mixing chamber is an annular space between the lower part of the hydrogen gas distribution pipe and the burner water chamber water-cooling pipes. The horizontal cross-sectional area of the mixing chamber is larger than that of the air distribution chamber in the horizontal direction.

[0009] A number of burner water chamber water-cooling pipes enclose a cylindrical whole. The number of burner water chamber water-cooling pipes corresponding to the area separated by the upper burner water chamber baffle is the same. There is a gap between adjacent two burner water chamber water-cooling pipes, and the width of the gap is 0.5 - 2 mm; the ratio of the number of burner water chamber water-cooling pipes to the number of rows of hydrogen injection holes on the hydrogen gas distribution pipe is 1 - 4; the overall wall thickness of the heat exchanger is 2 - 8 mm, the fin gap of the heat exchanger is 0.5 - 1 mm, and the ratio of the fin height to the fin pitch of the heat exchanger fins does not exceed 6.

[0010] The upper burner water chamber and the lower burner water chamber are annular cavities. A number of baffles are vertically and evenly arranged along the circumferential direction in the annular cavities of both. The number of baffles in the upper burner water chamber is twice that of the lower burner water chamber; adjacent burner water inlets and burner water outlets are provided at the top of the upper burner water chamber; both the burner water inlet and the burner water outlet are located between two adjacent baffles; the baffles in the lower burner water chamber completely separate the lower burner water chamber, and the baffles change the water flow channel in the burner into an S-shaped flow channel. The baffles in the lower burner water chamber are arranged at equal intervals along the circumferential direction and are directly below the first baffle in the upper burner water chamber.

[0011] The heat exchanger water channel is connected to the burner water chamber. A valve is provided on the pipeline connecting the heat exchanger water channel to the burner water chamber, and the water outlet of the heat exchanger water channel is used as the furnace body water outlet; or the heat exchanger water channel and the burner water chamber are respectively provided with water outlets to connect to the total water outlet of the wall-mounted boiler.

[0012] The heat exchanger fins are a circle of vertically arranged plate fins. The plate fins are arranged at equal intervals in the circumferential direction. The plate fins are straight fins or folded fins or bifurcated fins or a combination of the three; the heat exchanger fins include heat exchanger short fins and heat exchanger high fins. The combustion area is the heat exchanger short fins with a height of 10 - 30 mm. The space between the inner shell of the heat exchanger water channel and the inner cylinder of the heat exchanger is the heat exchanger high fins with a height of 20 - 100 mm. The heat exchanger short fins and the heat exchanger high fins are transitioned by a straight line or an arc. The surface of the heat exchanger fins is provided or not provided with an uneven surface.

[0013] The heat exchanger water channel includes water channel rib plates, an inner water channel shell, an outer water channel shell, and a water channel bottom plate; the two ends of the inner water channel shell and the outer water channel shell are tightly connected to the water channel bottom plate to form a sealed space, and the water channel rib plates divide the sealed space into an "S"-shaped water channel or a spiral water channel; the heat exchanger water inlet and the heat exchanger water outlet are opened on the outer water channel shell or the water channel bottom plate; the heat exchanger water channel has the following three specific structures:

[0014] I. The water channel rib plates include several annular rib plates arranged at equal intervals in the vertical direction and a vertical rib plate. The top of the vertical rib plate is connected to the bottom of the upper water channel plate, and the bottom of the vertical rib plate is connected to the top of the lower water channel plate; the vertical rib plate horizontally divides the annular rib plates. In the annular rib plates at the same height on both sides of the vertical rib plate, a bubble gap is provided between one side and the vertical rib plate, and a water channel is provided between the other side and the vertical rib plate; along the vertical direction on the same side of the vertical rib plate, the space between the annular rib plates and the vertical rib plate is alternately arranged as a bubble gap and a water channel; layers of water channels are formed between the annular rib plates and the vertical rib plate, the inner side of the outer water channel shell, the outer side of the inner water channel shell, and the water channel bottom plate, and water flows upward along the "S"-shaped water channel; the heat exchanger water inlet is opened on the side of the lowest-layer annular rib plate and the vertical rib plate where the bubble gap is provided, and the heat exchanger water outlet is opened on the side of the uppermost-layer water channel annular rib plate and the vertical rib plate where the bubble gap is provided. The heat exchanger water inlet and the heat exchanger water outlet can be arranged on the side of the outer water channel shell or on the surface of the water channel bottom plate;

[0015] II. The water channel rib plates include a spiral rib plate and two short vertical rib plates. The spiral rib plate takes the central axis of the outer water channel shell as the axis, and the short vertical rib plates are arranged at a distance of 20 - 100 mm from the water channel bottom plate between the spiral rib plate. Layers of water channels are formed between the spiral rib plate and the vertical rib plates, the inner side of the outer water channel shell, the outer side of the inner water channel shell, and the water channel bottom plate, and water flows upward along the spiral direction; the heat exchanger water outlet and the heat exchanger water inlet are respectively arranged at the ends of the upper and lower water channels. The heat exchanger water inlet and the heat exchanger water outlet can be arranged on the side of the outer water channel shell or on the surface of the water channel bottom plate, and a gap with a width ≤ (less than or equal to)1 mm is provided on the upper water channel plate at the end of the top water channel as a bubble discharge port;

[0016] III. All the water channel rib plates are vertical rib plates. 4 to 20 vertical rib plates are evenly arranged along the inner side surface of the water channel housing. The heat exchanger water inlet and the heat exchanger water outlet are arranged on the side surface or the water channel bottom surface of the upper or lower water channel housing according to the number of the vertical rib plates. Both the heat exchanger water inlet and the heat exchanger water outlet are located in the area between two adjacent baffles. A bubble gap is provided between the top of the vertical rib plate between the heat exchanger water inlet and the heat exchanger water outlet and the upper bottom plate of the water channel, and a bubble gap is provided between the bottom and the lower bottom plate of the water channel. The lengths of the remaining vertical rib plates are the same and shorter. A bubble gap is provided between one end and the water channel bottom plate, and a water channel is provided between the other end and the water channel bottom plate. The two adjacent shorter vertical rib plates along the circumferential direction are alternately provided with a bubble gap between the top and the upper bottom plate of the water channel, and a bubble gap between the bottom and the top of the lower bottom plate of the water channel. Water channels are formed between the vertical rib plates and the inner side of the water channel housing, the outer side of the inner water channel housing and the water channel bottom plate, and water flows up and down along the "S"-shaped water channel.

[0017] The flue includes a dew condensation pan, a condensate collection port and a chimney. The dew condensation pan is arranged at the bottom of the heat exchanger. The condensate collection port is arranged at the lowest position of the dew condensation pan. The chimney is arranged on the side of the furnace body. A burner cover plate is arranged outside the burner. The top of the heat exchanger is tightly connected to the bottom of the burner cover plate. The bottom of the heat exchanger is tightly connected to the top of the dew condensation pan. The inner side of the burner cover plate is tightly connected to the outer wall of the burner water chamber.

[0018] A heat exchanger middle rib plate structure is arranged on the inner side of the inner cylinder of the heat exchanger to form a water channel. Fins equal to or in proportion to the number of the heat exchanger fins are arranged on the outer side of the inner cylinder of the heat exchanger and are inserted into the heat exchanger fins, or the length of the heat exchanger fins is extended to increase the heat exchange amount.

[0019] The burner is made of a hydrogen embrittlement-resistant material or sprayed with a hydrogen embrittlement-resistant oxide coating. The inner cylinder of the heat exchanger is made of a high-temperature-resistant and dry-burning deformation-resistant stainless steel material. The surface of the heat exchanger fins is treated by silicon infiltration or anodized and plastic-coated. The flue is made of cast aluminum, cast iron, carbon steel, stainless steel, plastic or composite materials. Hydrogen concentration detection devices are arranged inside the combustion chamber, inside the packaging shell and inside the tail chimney. A pressure detection device and an air pressure valve are arranged on the hydrogen gas supply pipe. An ignition and flameout protection device, a flame rod or an ultraviolet flame detector are arranged inside the combustion chamber.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] The burner of the present invention adopts a fully premixed combustion mode with cylindrical central air intake, with uniform combustion, low resistance and strong adaptability to the wall-mounted boiler, and can be used as a retrofit solution for other cylindrical wall-mounted boilers. By adding a burner water chamber water-cooling pipe at the head of the burner to cool the flame root, the temperature of the combustion chamber is reduced, and NO xEmission is reduced, the hydrogen flame propagation speed is reduced, and the flashback risk is reduced. In the present invention, an expansion water tank is disposed inside the inner cylinder of the wall-mounted boiler heat exchanger, greatly reducing the overall space of the wall-mounted boiler while enhancing heat transfer by means of a narrow gap, being compact and beautiful.

[0022] Furthermore, the burner is made of a hydrogen embrittlement-resistant material or sprayed with a hydrogen corrosion-resistant material, having high strength and long service life; the inner cylinder of the burner is made of a high-temperature-resistant and dry-burning-resistant stainless steel material to prevent the inner cylinder from burning out and deforming; the heat exchanger is made of an aluminum-silicon-magnesium-based extruded aluminum material, having high strength and long service life, and at the same time, the fin surface is siliconized to enhance the anti-condensation water corrosion performance.

[0023] Furthermore, narrow-gap heat transfer is carried out in the form of folded fins or bifurcated fins, etc., with high heat transfer efficiency, and the heating demand can be met under a lower combustion load; the fin surface of the heat exchanger is provided with an uneven surface to improve the heat transfer efficiency.

[0024] Furthermore, a condensing heat exchanger with low price, high heat transfer efficiency and long service life is designed in combination with the domestic mature extruded aluminum process; it can be arbitrarily cut according to the length of the heat exchanger, having a simple structure, low cost, high production efficiency, and being adaptable to heating units of various power sizes; the extruded aluminum material has a large thermal conductivity.

[0025] Furthermore, the hydrogen leakage detection and explosion-proof safety equipment of the present invention are perfect, ensuring the safety and reliability of the hydrogen wall-mounted boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1a It is a front cross-sectional view schematic diagram of the overall structure of the wall-mounted boiler of the present invention.

[0027] Figure 1b It is a schematic diagram of the overall structure of the wall-mounted boiler of the present invention from another perspective.

[0028] Figure 2 It is a top cross-sectional view schematic diagram of the overall structure of the wall-mounted boiler of the present invention.

[0029] Figure 3 It is a schematic diagram of the burner structure of the wall-mounted boiler of the present invention.

[0030] Figure 4 It is a perspective view schematic diagram of the upper and lower water chambers of the burner.

[0031] Figure 5a It is a schematic diagram of the folded fin structure of the heat exchanger of the present invention.

[0032] Figure 5b It is a schematic diagram of the bifurcated fin structure of the heat exchanger of the present invention.

[0033] Figure 6 It is a schematic diagram of the heat exchanger structure of the wall-mounted boiler of the present invention.

[0034] Figure 7aThis is a schematic structural diagram of the first scheme of the heat exchanger water channel of the present invention.

[0035] Figure 7b This is a schematic structural diagram of the second scheme of the heat exchanger water channel of the present invention.

[0036] Figure 7c This is a schematic structural diagram of the third scheme of the heat exchanger water channel of the present invention.

[0037] Among them, 1: burner, 11: hydrogen gas distribution pipe, 111: hydrogen injection hole, 12: air distribution chamber, 13: mixing chamber, 14: burner water chamber, 141: upper burner water chamber, 142: water-cooled pipe of the burner water chamber, 143: lower burner water chamber, 15: ignition pin, 16: burner water inlet, 17: burner water outlet, 18: burner cover plate, 2: heat exchanger, 21: combustion chamber, 22: heat exchanger fins, 221: short heat exchanger fins, 222: high heat exchanger fins, 223: transition section of the heat exchanger fins, 224: folded fins of the heat exchanger, 225: bifurcated fins of the heat exchanger, 23: heat exchanger water channel, 231: water channel rib plate, 2311: annular rib plate, 2312: vertical rib plate, 2313: spiral rib plate, 2315: short vertical rib plate, 232: inner shell of the water channel, 233: outer shell of the water channel, 234: bottom plate of the water channel, 2341: upper bottom plate of the water channel, 2342: lower bottom plate of the water channel, 2343: steam bubble discharge port, 24: inner cylinder of the heat exchanger, 25: heat exchanger water inlet, 26: heat exchanger water outlet, 3: expansion tank, 4: flue, 41: dew-catching tray, 42: condensate collection port, 43: chimney. Detailed implementation manners

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

[0039] Refer to Figure 1a 、 Figure 1b and Figure 2, a cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchange compact hydrogen wall-mounted boiler, including a burner 1, a heat exchanger 2, an expansion tank 3, a flue 4 and other wall-mounted boiler accessories; the burner 1 includes a hydrogen gas distribution pipe 11, an air distribution chamber 12, a mixing chamber 13, a burner water chamber 14, an ignition needle 15, a burner water inlet 16, a burner water outlet 17 and a burner cover plate 18; the heat exchanger 2 includes a combustion chamber 21, heat exchanger fins 22, a heat exchanger water channel 23, a heat exchanger inner cylinder 24, a heat exchanger water inlet 25 and a heat exchanger water outlet 26; the flue 4 includes a dew pan 41, a condensate collection port 42 and a chimney 43; the burner 1, the heat exchanger 2, the expansion tank 3 and the flue 4 are all cylindrical and arranged coaxially, forming a center-intake hydrogen combustion wall-mounted boiler structure with an overall cylindrical shape; the burner 1 is located at the upper center of the heat exchanger 2, the expansion tank 3 is located at the inner center of the lower part of the heat exchanger 2 inside the heat exchanger inner cylinder 24, and the flue 4 is located at the bottom of the heat exchanger 2; a combustion chamber 21 is formed between the outer side of the lower part of the burner 1 and the inner side of the upper part of the heat exchanger 2, and the heat exchanger fins 22 and the heat exchanger water channel 23 are the main heat exchange areas; the dew pan 41 and the chimney 43 are the main smoke exhaust areas; after the hydrogen gas is ejected from the hydrogen gas distribution pipe 11, it vertically crosses and mixes with the air flowing from the air distribution chamber 12 in the mixing chamber 13. The mixed gas is ejected from the side gap at the lower part of the burner water chamber 14 and then enters the combustion chamber 21. After being ignited by the ignition needle 15, it burns in the combustion chamber 21. The generated high-temperature flue gas flows downward along the gap between the heat exchanger fins 22 and the heat exchanger inner cylinder 24, transferring sensible heat and latent heat to the working medium in the heat exchanger water channel 23. The generated condensate is collected by the dew pan 41 and discharged from the condensate collection port 42, and the generated low-temperature flue gas is collected by the dew pan 41 and discharged from the chimney 43.

[0040] The working medium water can first enter the burner water chamber 14 from the burner water inlet 16, and then be discharged from the burner water chamber 14 from the burner water outlet 17, enter the heat exchanger water channel 23 from the heat exchanger water inlet 25, and then be discharged from the wall-mounted boiler from the heat exchanger water outlet 26.

[0041] The burner water chamber 14 and the heat exchanger water channel 23 can also adopt separate water circuits. One way of water enters the burner water chamber 14 from the burner water inlet 16 and is discharged from the wall-mounted boiler from the burner water outlet 17, and the other way of water enters the heat exchanger water channel 23 from the heat exchanger water inlet 25 and is discharged from the wall-mounted boiler from the heat exchanger water outlet 26.

[0042] Reference Figure 1a 、 Figure 1b 、 Figure 3, the hydrogen gas distribution pipe 11 includes two straight pipe segments and an elbow. The hydrogen gas distribution pipe 11 is vertically arranged, and the axis of the vertical section of the hydrogen gas distribution pipe 11 is the same as the axis of the burner 1. The bottom height of the hydrogen gas distribution pipe 11 is the same as the top height of the lower water chamber 143 of the burner. A circular baffle is provided at the top of the lower water chamber 143 of the burner to block the bottom of the hydrogen gas distribution pipe 11 and the bottom of the mixing chamber 13 at the same time. The bottom of the hydrogen gas distribution pipe 11 and the bottom of the mixing chamber 13 can also be blocked by baffles respectively; 4 to 10 rows of hydrogen spray holes 111 are evenly opened on the lower pipe wall of the vertical section of the hydrogen gas distribution pipe 11; the air distribution chamber 12 is an annular space between the upper part of the hydrogen gas distribution pipe 11 and the upper water chamber 141 of the burner, and the mixing chamber 13 is an annular space between the lower part of the hydrogen gas distribution pipe 11 and the water-cooled pipe 142 of the burner water chamber; the cross-sectional area of the mixing chamber 13 in the horizontal direction is larger than the cross-sectional area of the air distribution chamber 12 in the horizontal direction, which is used to generate an internal circulation of the mixed gas and strengthen the mixing of hydrogen and air.

[0043] Reference Figure 1a , Figure 1b , Figure 2 , Figure 3 , Figure 4, the burner water chamber 14 includes an upper burner water chamber 141, burner water chamber water-cooling pipes 142, and a lower burner water chamber 143. The upper burner water chamber 141 is an annular cavity. The cross-section of the cavity in the vertical direction is preferably a parallelogram. 4 to 10 baffles are vertically and evenly arranged along the circumferential direction in the cavity. An adjacent burner water inlet 16 and a burner water outlet 17 are provided at the top of the upper burner water chamber 141. The burner water inlet 16 and the burner water outlet 17 are located between two adjacent baffles. The baffles include a first baffle and a second baffle. The bottom of the first baffle is connected to the bottom of the upper burner water chamber 141, and the top of the first baffle is ≤1 mm away from the top of the upper burner water chamber 141, which is used to separate the water path and discharge air bubbles. The bottom of the second baffle is connected to the bottom of the upper burner water chamber 141, and the top of the second baffle is 30 to 100 mm away from the top of the upper burner water chamber, which is used for the turning of water. The baffles on both sides of the burner water inlet 16 and the burner water outlet 17 are first baffles, and the remaining baffles are arranged alternately as second baffles and first baffles. The baffle adjacent to the baffles on both sides of the burner water inlet 16 and the burner water outlet 17 is a second baffle. The burner water chamber water-cooling pipes 142 are surrounded by 8 to 40 vertical long pipes to form a cylindrical water-cooling pipe group. The horizontal cross-section of a single burner water chamber water-cooling pipe 142 can be triangular, rectangular, trapezoidal, circular, etc. Water flows inside the burner water chamber water-cooling pipes 142. The burner water chamber water-cooling pipes 142 are located directly below the area clamped by the baffles of the upper burner water chamber 141. Each clamped area corresponds to the same number of burner water chamber water-cooling pipes 142, and the corresponding number can be 2 to 4. There is a gap between two adjacent burner water chamber water-cooling pipes 142, and the width of the gap is 0.5 to 2 mm. The number of rows of spray holes on the hydrogen gas distribution pipe 11 is in proportion to the number of burner water chamber water-cooling pipes 142, and the ratio of the latter to the former can be 1 to 4. The burner water chamber water-cooling pipes 142 and the spray holes of the corresponding hydrogen gas distribution pipe 11 are located in the same radial direction. The hydrogen jet ejected from the spray holes of the hydrogen gas distribution pipe 11 returns to the mixing chamber 13 after reaching the burner water chamber water-cooling pipes 142 and further mixes with air. The lower burner water chamber 143 is an annular cavity, and 2 to 5 square baffles are vertically arranged inside. The number of baffles in the lower burner water chamber 143 is half of the number of baffles in the upper burner water chamber 141. Each baffle in the lower burner water chamber completely separates the lower burner water chamber 143. The baffles in the lower burner water chamber 143 are arranged at equal intervals along the circumferential direction and are located directly below the first baffle of the upper burner water chamber 141.

[0044] Reference Figure 5a , Figure 5b , the heat exchanger fins 22 are a circle of vertically arranged plate fins. The plate fins are arranged at equal intervals along the circumferential direction. The plate fins can be straight heat exchanger fins, folded heat exchanger fins 224, forked heat exchanger fins 225, or a combination of the three.

[0045] Reference Figure 6, the combustion area is the short fin 221 of the heat exchanger, with a height of 10 - 30 mm. Between the inner shell 232 of the water channel of the heat exchanger and the inner cylinder 24 of the heat exchanger is the tall fin 222 of the heat exchanger, with a height of 20 - 100 mm. The end of the tall fin 222 of the heat exchanger may or may not be in contact with the outer wall of the inner cylinder 24 of the heat exchanger. The short fin 221 and the tall fin 222 of the heat exchanger are transitioned by a straight line or an arc. The surface of the fin 22 of the heat exchanger may be provided with uneven surfaces such as corrugations or sawteeth to enhance heat transfer.

[0046] Reference Figure 6 、 Figure 7a , the water channel 23 of the heat exchanger includes a water channel rib plate 231, an inner shell 232 of the water channel, an outer shell 233 of the water channel, and a bottom plate 234 of the water channel; the present invention provides the following three structural water channels 23 of the heat exchanger. As a preferred solution for Scheme 1, the water channel rib plate 231 includes 4 - 30 annular rib plates 2311 arranged at equal intervals in the vertical direction and a vertical rib plate 2312. The top of the vertical rib plate 2312 is in contact with the bottom of the upper bottom plate 2341 of the water channel, and the bottom of the vertical rib plate 2312 is in contact with the top of the lower bottom plate 2342 of the water channel. The vertical rib plate 2312 horizontally divides the annular rib plates 2311. Among the annular rib plates 2311 at the same height on both sides of the vertical rib plate 2312, one side is ≤ 1 mm away from the vertical rib plate 2312 to separate the water path and discharge air bubbles, and the other side is 20 - 100 mm away from the vertical rib plate 2312 for the turning of water. The annular rib plates 2311 on the same side of the vertical rib plate 2312 are alternately set to be ≤ 1 mm away from or 20 - 100 mm away from the vertical rib plate 2312 in the vertical direction; a layer of water path is formed between the annular rib plates 2311 and the vertical rib plate 2312, the inner side of the outer shell 233 of the water channel, and the outer side of the inner shell 232 of the water channel. Water flows upward along the "S"-shaped water channel; a heat exchanger water inlet 25 is provided on one side of the annular rib plate 2311 of the lowest layer of the water path that is ≤ 1 mm away from the vertical rib plate 2312, and a heat exchanger water outlet 26 is provided on one side of the annular rib plate 2311 of the uppermost layer of the water path that is ≤ 1 mm away from the vertical rib plate 2312. The heat exchanger water inlet 25 and the heat exchanger water outlet 26 can be provided on the side surface of the outer shell 233 of the water channel or on the surface of the bottom plate 234 of the water channel.

[0047] Reference Figure 7b, in Solution 2, the water channel rib plate 231 includes a spiral rib plate 2313 and two short vertical rib plates 2315. The spiral rib plate 2313 takes the central axis of the water channel housing 233 as the axis. The short vertical rib plates 2315 are arranged at a position 20 - 100 mm away from the water channel bottom plate 234 on the spiral rib plate 2313 to block the water path. A layer of heat exchange water path is formed between the spiral rib plate 2313, the short vertical rib plates 2315, the inner side of the water channel housing 233 and the outer side of the water channel inner housing 232. The heat exchanger water outlet 26 and the heat exchanger water inlet 25 are respectively arranged at the ends of the upper and lower water paths. The heat exchanger water inlet 25 and the heat exchanger water outlet 26 can be arranged on the side surface of the water channel housing 233 or on the surface of the water channel bottom plate 234. The water flows upward along the spiral direction. A gap with a width ≤ 1 mm is set on the upper bottom plate 2341 of the water channel at the end of the top water path as the bubble discharge outlet 2343.

[0048] Reference Figure 7c , in Solution 3, the water channel rib plates 231 are all vertical rib plates 2312. 4 - 20 vertical rib plates 2312 are evenly arranged along the inner side surface of the water channel housing 233. The heat exchanger water inlet 25 and the heat exchanger water outlet 26 are arranged on the side surface of the upper or lower water channel housing 233 or on the surface of the water channel bottom plate 234 according to the number of the vertical rib plates 2312. The heat exchanger water inlet 25 and the heat exchanger water outlet 26 are both located in the area clamped by two adjacent baffles. The top of the vertical rib plate 2312 clamped by the heat exchanger water inlet 25 and the heat exchanger water outlet 26 is ≤ 1 mm away from the bottom of the upper water channel bottom plate 2341, and the bottom is ≤ 1 mm away from the top of the lower water channel bottom plate 2342, which is used to separate the water path and discharge bubbles. The lengths of the remaining vertical rib plates 2312 are the same and shorter. One end is ≤ 1 mm away from the water channel bottom plate 234 to separate the water path and discharge bubbles, and the other end is 20 - 100 mm away from the water channel bottom plate 2342 for the water to turn. Among the two adjacent shorter vertical rib plates 2315 along the circumferential direction, one has a top ≤ 1 mm away from the bottom of the upper water channel bottom plate 2341, and the other has a bottom ≤ 1 mm away from the top of the lower water channel bottom plate 2342. A heat exchange water path is formed between the vertical rib plates 2312, the inner side of the water channel housing 233, the upper water channel bottom plate 2341, the lower water channel bottom plate 2342 and the outer side of the water channel inner housing 232. The water flows up and down along the "S" - shaped water path.

[0049] Reference Figure 6 , Figure 7a , Figure 7b , Figure 7c, the heat exchanger fins 22, the inner water channel shell 232 and the vertical rib plates 2312 in the third solution are processed by integral extrusion aluminum and cutting process, and the water channel outer shell 233, the water channel bottom plate 234 and the water channel rib plates 231 in the first and second solutions are processed by integral casting or welding process. The overall wall thickness of the heat exchanger 2 is 2-8 mm, the gap between the heat exchanger fins 22 is 0.5-1 mm, and the ratio of the fin height to the fin pitch of the heat exchanger fins 22 does not exceed 6. The sizes of the burner water inlet 16, the burner water outlet 17, the heat exchanger water inlet 25 and the heat exchanger water outlet 26 are designed according to the water flow velocity. The water flow velocities of the burner water inlet 16 and the heat exchanger water inlet 25 are controlled at 0.2-0.5 m / s, the water flow velocities of the burner water outlet 17 and the heat exchanger water outlet 26 are controlled at 0.9-1.8 m / s, and the water flow velocities in the burner water chamber 14 and the heat exchanger water channel 23 are controlled at 0.2-1.8 m / s.

[0050] A rib plate structure similar to that of the heat exchanger 2 can be arranged inside the inner cylinder 24 of the heat exchanger to form a water path. Fins with the same number or in proportion to the number of the heat exchanger fins 22 are arranged outside the inner cylinder 24 of the heat exchanger and inserted into the heat exchanger fins 22, or the length of the heat exchanger fins 22 is extended to increase the heat exchange amount, so as to form different types of furnaces such as wall-mounted boilers, floor-standing furnaces or commercial water heaters.

[0051] The burner 1 is made of a hydrogen embrittlement-resistant material or sprayed with a hydrogen embrittlement-resistant oxide coating. The inner cylinder 24 of the heat exchanger is made of a high-temperature-resistant and dry-burning deformation-resistant stainless steel material. The surface of the heat exchanger fins 22 is treated by silicon infiltration or anodized and plastic-coated to enhance the anti-condensate corrosion performance. The flue 4 is made of cast aluminum, cast iron, carbon steel, stainless steel, plastic or composite material. The top of the heat exchanger 2 is tightly connected to the burner cover plate 18, the bottom of the heat exchanger 2 is tightly connected to the top of the dew pan 41, and the inner ring of the burner cover plate 18 is tightly connected to the outside of the burner water chamber 14 to ensure good sealing performance.

[0052] Hydrogen concentration detection devices are arranged inside the combustion chamber 21 of the wall-mounted boiler, inside the packaging shell and inside the tail chimney 43. Pressure detection devices and air pressure valves are arranged on the hydrogen pipeline. Ignition and flameout protection devices, flame rods or ultraviolet flame detectors, and ignition and flameout protection devices are arranged inside the combustion chamber 21. The flame rod or ultraviolet flame detector is connected to the controller. When the hydrogen concentration or the pressure of the hydrogen pipeline is abnormal, the controller issues an instruction to close the hydrogen air pressure valve in time, and the air path is purged by the fan, prompting the user to open the shell of the wall-mounted boiler and ventilate; ignition is carried out when the volume concentration of hydrogen in the combustion chamber is 4%-10%, ensuring that the volume concentration of hydrogen in the combustion chamber does not exceed 16% all the time. Before each ignition, air purging is carried out for 3-5 minutes. After flameout, the hydrogen valve is immediately closed, and air purging is carried out for 3-5 minutes before ignition again.

[0053] In summary, for the cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchange compact hydrogen wall-mounted boiler provided by the present invention, after hydrogen is ejected from the hydrogen gas distribution pipe, it mixes with the air flowing from the air distribution chamber in the mixing chamber. The mixed gas is ejected through the side gap at the lower part of the burner water chamber and then ignited and burned. The flue gas condenses and exchanges heat in the gap between the heat exchanger fins and the inner cylinder of the heat exchanger, and the condensed water and flue gas are discharged after being collected by the dew tray. The working medium first enters the burner water chamber and then enters the heat exchanger water channel, or the heat exchanger water channel and the burner water chamber water circuit are independent; the working medium in the heat exchanger flows upward or up and down along the "S"-shaped water channel, or flows upward along the spiral water channel, and the working medium in the burner flows up and down along the "S"-shaped water channel; the expansion tank is placed inside the inner cylinder of the heat exchanger. This wall-mounted boiler can solve the problems existing in hydrogen combustion, such as high flame temperature, high NOx emission, easy flashback, low heat load and safety problems, and provides ideas for the design of a safe, energy-saving, environment-friendly and compact hydrogen-fired wall-mounted boiler.

[0054] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A cylindrical premixed water-cooled combustion extruded aluminum fin heat exchange compact hydrogen wall-mounted boiler, characterized in that, It includes a burner (1), a heat exchanger (2), an expansion tank (3) and a flue (4); the burner (1), the heat exchanger (2), the expansion tank (3) and the flue (4) are arranged in a cylindrical shape and coaxially, forming a central air intake hydrogen combustion wall-mounted boiler structure with an overall cylindrical shape; a heat exchanger inner cylinder (24) is arranged at the lower part of the heat exchanger (2), heat exchanger fins (22) are arranged circumferentially on the outer side of the heat exchanger inner cylinder (24), and the heat exchanger fins (22) at the top of the heat exchanger inner cylinder (24) enclose a receiving space, the burner (1) is arranged in the receiving space, and a combustion chamber (21) is formed between the outer side of the lower part of the burner (1) and the inner side of the upper part of the heat exchanger (2); the expansion tank (3) is located at the center inside the heat exchanger inner cylinder (24), and the flue (4) is located at the bottom of the heat exchanger (2); the top end of the heat exchanger (2) is sealed, and the bottom end is connected to the flue (4), and a heat exchanger water channel (23) is arranged on the side surface of the heat exchanger (2); the burner (1) adopts a premixed water-cooled burner; the burner (1) includes a hydrogen gas distribution pipe (11), an air distribution chamber (12), a mixing chamber (13), a burner water chamber (14), an ignition needle (15), a burner water inlet (16), a burner water outlet (17) and a burner cover plate (18); the hydrogen gas distribution pipe (11) extends into the center of the burner (1), and hydrogen gas spray holes (111) are opened at the lower part of the hydrogen gas distribution pipe (11); the burner water chamber (14) includes a burner upper water chamber (141), a burner lower water chamber (143) and a burner water chamber water-cooled pipe (142) connecting the two, and the burner water chamber water-cooled pipe (142) is arranged along one week of the burner (1), the air distribution chamber (12) is an annular space between the upper part of the hydrogen gas distribution pipe (11) and the burner upper water chamber (141), the mixing chamber (13) is an annular space between the lower part of the hydrogen gas distribution pipe (11) and the burner water chamber water-cooled pipe (142), and the cross-sectional area of the mixing chamber (13) in the horizontal direction is larger than the cross-sectional area of the air distribution chamber (12) in the horizontal direction; a plurality of burner water chamber water-cooled pipes (142) enclose a cylindrical whole, the number of burner water chamber water-cooled pipes (142) corresponding to the area separated by the baffle of the burner upper water chamber (141) is the same, and a gap is left between two adjacent burner water chamber water-cooled pipes (142), and the width of the gap is 0.5 - 2 mm; the ratio of the number of burner water chamber water-cooled pipes (142) to the number of rows of hydrogen gas spray holes (111) on the hydrogen gas distribution pipe (11) is 1 - 4; the overall wall thickness of the heat exchanger (2) is 2 - 8 mm, the gap between the heat exchanger fins (22) is 0.5 - 1 mm, and the ratio of the fin height to the fin pitch of the heat exchanger fins (22) does not exceed 6.

2. A cylindrical premixed water-cooled combustion extruded aluminum fin heat exchange compact hydrogen wall-mounted boiler according to claim 1, characterized in that, The upper water chamber (141) and the lower water chamber (143) of the burner are annular cavities. A number of baffles are vertically and evenly arranged along the circumferential direction in the annular cavities of both. The number of baffles in the upper water chamber (141) of the burner is twice that of the lower water chamber (143) of the burner; at the top of the upper water chamber (141) of the burner, an adjacent burner water inlet (16) and a burner water outlet (17) are provided; both the burner water inlet (16) and the burner water outlet (17) are located between two adjacent baffles; the baffles in the lower water chamber (143) of the burner completely separate the lower water chamber (143) of the burner, and the baffles change the water flow channel in the burner (1) into an S-shaped flow channel. The baffles in the lower water chamber (143) of the burner are arranged at equal intervals along the circumferential direction and are directly below the first baffle in the upper water chamber (141) of the burner.

3. A cylindrical premixed water-cooled combustion extruded aluminum fin heat exchange compact hydrogen wall-mounted boiler according to claim 1, characterized in that, The heat exchanger water channel (23) is connected to the burner water chamber (14). A valve is provided on the pipeline where the heat exchanger water channel (23) is connected to the burner water chamber (14). The water outlet of the heat exchanger water channel (23) serves as the furnace body water outlet; or the heat exchanger water channel (23) and the burner water chamber (14) are respectively provided with water outlets to connect to the total water outlet of the wall-mounted boiler.

4. A cylindrical premixed water-cooled combustion extruded aluminum fin heat exchange compact hydrogen wall-mounted boiler according to claim 1, characterized in that, The heat exchanger fins (22) are a circle of vertically arranged plate fins. The plate fins are arranged at equal intervals along the circumferential direction. The plate fins are straight fins or folded fins or bifurcated fins or a combination of the three; the heat exchanger fins (22) include heat exchanger short fins (221) and heat exchanger tall fins (222). The combustion area is the heat exchanger short fins (221) with a height of 10 - 30 mm. Between the inner shell (232) of the heat exchanger water channel and the inner cylinder (24) of the heat exchanger are the heat exchanger tall fins (222) with a height of 20 - 100 mm. The heat exchanger short fins (221) and the heat exchanger tall fins (222) are transitioned by a straight line or an arc. The surface of the heat exchanger fins (22) is provided or not provided with an uneven surface.

5. A cylindrical premixed water-cooled combustion extruded aluminum fin heat exchange compact hydrogen wall-mounted boiler according to claim 1, characterized in that, The heat exchanger water channel (23) includes a water channel rib plate (231), a water channel inner shell (232), a water channel outer shell (233), and a water channel bottom plate (234); the two ends of the water channel inner shell (232) and the water channel outer shell (233) are tightly connected to the water channel bottom plate (234) to form a sealed space. The water channel rib plate (231) divides the sealed space into an "S"-shaped water channel or a spiral water channel; a heat exchanger water inlet (25) and a heat exchanger water outlet (26) are provided on the water channel outer shell (233) or the water channel bottom plate (234); the heat exchanger water channel has the following three specific structures:

1. The water channel rib plate (231) includes several annular rib plates (2311) arranged at equal intervals in the vertical direction and a vertical rib plate (2312). The top of the vertical rib plate (2312) is connected to the bottom of the upper water channel bottom plate (2341), and the bottom of the vertical rib plate (2312) is connected to the top of the lower water channel bottom plate (2342). The vertical rib plate (2312) horizontally divides the annular rib plates (2311). In the annular rib plates (2311) at the same height on both sides of the vertical rib plate (2312), a bubble gap is provided between one side and the vertical rib plate (2312), and a water channel is provided between the other side and the vertical rib plate (2312). Along the vertical direction on the same side of the vertical rib plate (2312), bubble gaps and water channel annular rib plates (2311) are arranged at intervals with the vertical rib plate (2312). Layers of water channels are formed between the annular rib plates (2311) and the vertical rib plate (2312), the inner side of the water channel outer shell (233), the outer side of the water channel inner shell (232), and the water channel bottom plate (234). Water flows upward along the "S"-shaped water channel. A heat exchanger water inlet (25) is provided on the side of the lowest-layer annular rib plate (2311) where a bubble gap is provided with the vertical rib plate (2312), and a heat exchanger water outlet (26) is provided on the side of the uppermost-layer water channel annular rib plate (2311) where a bubble gap is provided with the vertical rib plate (2312). The heat exchanger water inlet (25) and the heat exchanger water outlet (26) can be provided on the side of the water channel outer shell (233) or on the surface of the water channel bottom plate (234).

2. The water channel rib plate (231) includes a spiral rib plate (2313) and two short vertical rib plates (2315). The spiral rib plate (2313) takes the central axis of the water channel outer shell (233) as the axis, and the short vertical rib plates (2315) are arranged at a distance of 20 - 100 mm from the water channel bottom plate (234) between the spiral rib plate (2313). Layers of water channels are formed between the spiral rib plate (2313) and the vertical rib plate (2312), the inner side of the water channel outer shell (233), the outer side of the water channel inner shell (232), and the water channel bottom plate (234). Water flows upward along the spiral direction. A heat exchanger water outlet (26) and a heat exchanger water inlet (25) are respectively provided at the ends of the upper and lower water channels. The heat exchanger water inlet (25) and the heat exchanger water outlet (26) can be provided on the side of the water channel outer shell (233) or on the surface of the water channel bottom plate (234). A gap with a width ≤ 1 mm is provided on the upper water channel bottom plate (2341) at the end of the top water channel as a bubble discharge port (2343). III. All the water channel rib plates (231) are vertical rib plates (2312). 4 to 20 vertical rib plates (2312) are evenly arranged along the inner side of the water channel housing (233). The heat exchanger water inlet (25) and the heat exchanger water outlet (26) are arranged on the side of the upper or lower water channel housing (233) or on the surface of the water channel bottom plate (234) according to the number of the vertical rib plates (2312); both the heat exchanger water inlet (25) and the heat exchanger water outlet (26) are located in the area between two adjacent baffles. A bubble gap is provided between the top of the vertical rib plate (2312) between the heat exchanger water inlet (25) and the heat exchanger water outlet (26) and the upper water channel bottom plate (2341), and a bubble gap is provided between the bottom and the lower water channel bottom plate (2342). The lengths of the remaining vertical rib plates (2312) are the same and shorter. A bubble gap is provided between one end and the water channel bottom plate (234), and a water channel is provided between the other end and the water channel bottom plate (234); for two adjacent shorter vertical rib plates (2315) along the circumferential direction, one has a bubble gap provided between its top and the upper water channel bottom plate (2341), and the other has a bubble gap provided between its bottom and the top of the lower water channel bottom plate (2342); a water path is formed between the vertical rib plate (2312) and the inner side of the water channel housing (233), the outer side of the water channel inner housing (232), and the water channel bottom plate (234), and water flows up and down along the "S"-shaped water channel.

6. A cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchange compact hydrogen wall-mounted boiler according to claim 1, characterized in that: The flue (4) includes a dew condensation tray (41), a condensate collection port (42), and a chimney (43); the dew condensation tray (41) is arranged at the bottom of the heat exchanger (2), the condensate collection port (42) is arranged at the lowest position of the dew condensation tray (41), and the chimney (43) is arranged on the side of the furnace body; a burner cover plate (18) is arranged outside the burner (1), the top of the heat exchanger (2) is tightly connected to the bottom of the burner cover plate (18), the bottom of the heat exchanger (2) is tightly connected to the top of the dew condensation tray (41), and the inner side of the burner cover plate (18) is tightly connected to the outer wall of the burner water chamber (14).

7. A cylindrical premixed water-cooled combustion extrusion aluminum fin heat exchange compact hydrogen wall-mounted boiler according to claim 1, characterized in that, A heat exchanger middle rib plate structure is arranged inside the inner cylinder (24) of the heat exchanger to form a water channel. Fins equal in number to or in proportion to the heat exchanger fins (22) are arranged outside the inner cylinder (24) of the heat exchanger and are inserted into the heat exchanger fins (22) in an interleaved manner, or the length of the heat exchanger fins (22) is extended to increase the heat exchange amount.

8. A cylindrical premixed water-cooled combustion extruded aluminum fin heat exchange compact hydrogen wall-mounted boiler according to claim 1, characterized in that, The burner (1) is made of a hydrogen embrittlement-resistant material or sprayed with a hydrogen embrittlement-resistant oxide coating. The inner cylinder (24) of the heat exchanger is made of a high-temperature-resistant and dry-burning deformation-resistant stainless steel material. The surface of the heat exchanger fins (22) is subjected to silicon infiltration treatment or anodized and plastic-coated treatment. The flue (4) is made of cast aluminum, cast iron, carbon steel, stainless steel, plastic, or composite material; hydrogen concentration detection devices are arranged inside the combustion chamber (21), inside the packaging housing, and inside the tail chimney (43). A pressure detection device and an air pressure valve are arranged on the hydrogen gas distribution pipe (11). An ignition and flameout protection device, a flame rod, or an ultraviolet flame detector is arranged inside the combustion chamber (21).

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