Low-NOx combustion compact type condensing boiler device based on deep hydrogen doping

Abstract

The invention discloses a low-NOx combustion compact type condensing boiler device based on deep hydrogen doping, and relates to the technical field of condensing boilers, the low-NOx combustion compact type condensing boiler device comprises a combustion furnace, a premixing box is arranged below the combustion furnace, and a hydrogen injection pipe and an air injection pipe are fixed to the two sides of the premixing box respectively; the premixing box is arranged below the combustion furnace, and the gas uniform mixing mechanism driven by the motor to operate is arranged in the premixing box, so that air and hydrogen can be fully mixed before combustion, deep hydrogen doping is achieved, the combustion uniformity and completeness in the combustion furnace in the follow-up process are ensured, generation of nitric oxide is reduced to a large extent, and the environment-friendly effect is achieved; an air preheating box and a heat exchange box are arranged at the top end of the combustion furnace, water can be heated through smoke waste heat, air can be preheated before mixing, and therefore the initial temperature of mixed gas is increased, the fuel ignition point is reduced, the reaction speed is increased, and the combustion efficiency is remarkably improved; and the heat recovery efficiency is improved by utilizing a dual recovery means for the flue gas waste heat.

Description

Technical Field

[0001] The invention relates to the technical field of condensing boilers, and in particular to a compact condensing boiler device with low NOx combustion based on deep hydrogen doping. Background Art

[0002] The hot water or steam generated in the boiler can directly provide the required thermal energy for industrial production and people's lives, or it can be converted into mechanical energy through a steam power device, or the mechanical energy can be converted into electrical energy through a generator. The boiler that provides hot water is called a hot water boiler, which is mainly used for life and also has a small number of applications in industrial production. The boiler that generates steam is called a steam boiler, often referred to as a boiler, and is mostly used in thermal power plants, ships, locomotives and industrial and mining enterprises.

[0003] A condensing boiler is a high-efficiency energy-saving equipment that significantly improves thermal efficiency by recovering the latent heat of water vapor in high-temperature flue gas. Compared with traditional boilers, its thermal efficiency can exceed 100% (calculated based on the low calorific value of the fuel), while reducing pollutant emissions. It is widely used in heating, industry and other fields. Condensing boilers based on deep hydrogen blending deeply blend hydrogen into natural gas, using full premixed combustion and condensation technology, which significantly reduces nitrogen oxide emissions and achieves environmental protection and energy saving.

[0004] Most of the existing condensing boiler devices have a single function. It is not convenient to fully mix different gases before the fuel gas is burned, so it is impossible to ensure the uniformity and completeness of combustion. The combustion efficiency is low, resulting in more nitrogen oxides being generated, which is not environmentally friendly. In addition, the means for recovering the waste heat of the flue gas during use are relatively single, and the heat in the flue gas cannot be fully and efficiently recovered, which is not energy-saving enough. Therefore, the present invention proposes a compact condensing boiler device with low NOx combustion based on deep hydrogen doping to solve the problems existing in the prior art. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to propose a compact condensing boiler device with low NOx combustion based on deep hydrogen doping, so as to solve the problems that the existing condensing boiler device is not convenient for fully mixing different gases before the fuel gas is burned, thereby failing to ensure the uniformity and completeness of combustion, and the waste heat recovery method for the flue gas is relatively single, and the heat in the flue gas cannot be fully and efficiently recovered.

[0006] In order to achieve the purpose of the present invention, the present invention is implemented through the following technical solutions: a compact condensing boiler device with low NOx combustion based on deep hydrogen doping, including a combustion furnace, a premixing box is arranged below the combustion furnace, a hydrogen injection pipe and an air injection pipe are respectively fixed on both sides of the premixing box, a gas mixing mechanism driven by a motor is arranged inside the premixing box, a second gas pipe is connected to the top of the premixing box through a first gas pipe, a third gas pipe is fixed on the second gas pipe that runs through the interior of the combustion furnace, an ignition needle adapted to the third gas pipe is fixed below the interior of the combustion furnace, and an ignition needle adapted to the third gas pipe is fixed at the top of the interior of the combustion furnace A steam water tank is fixed, and steam output pipes that penetrate to the outside of the combustion furnace are fixed to the front and rear side walls of the steam water tank. The top of the combustion furnace is connected to an air preheating box through a smoke exhaust pipe. A blower is fixed to the top of the air preheating box. A preheating coil located inside the air preheating box is fixed at the output end of the blower. A return air pipe is connected between the preheating coil and the air injection pipe. A heat exchange box is provided on the side of the air preheating box away from the smoke exhaust pipe. A heat exchange coil connected to the air preheating box is fixed inside the heat exchange box. The output end of the heat exchange coil penetrates to the outside of the air preheating box and is fixed with a discharge pipe.

[0007] A further improvement is that the gas mixing mechanism includes a rotating shaft rotatably connected to the inside of the premixing box and arc-shaped stirring plates symmetrically distributed on the periphery of the rotating shaft, and connecting rods are symmetrically fixed between the arc-shaped stirring plates and the rotating shaft.

[0008] Further improvements are: gas flow control valves are fixed on the hydrogen injection pipe and the air injection pipe, the first gas pipe is symmetrically fixed to the top of the premixing box, an electronic control valve is fixed on the first gas pipe, the third gas pipe is equidistantly fixed to the top of the second gas pipe, and the ignition needles are equidistantly distributed inside the combustion furnace and correspond to the position of the third gas pipe.

[0009] A further improvement is that: a water supply pipe and a drain pipe that penetrate to the outside of the combustion furnace are fixed to the two side walls of the steam water tank, and a liquid flow control valve is fixed on the water supply pipe and the drain pipe. An impurity filter is fixed between the lower part of the outer wall of the steam water tank and the inner wall of the combustion furnace.

[0010] A further improvement is that a temperature sensor and a liquid level sensor are fixed to the top of the steam water tank, the detection end of the liquid level sensor extends to the bottom of the steam water tank, and a display screen electrically connected to the temperature sensor and the liquid level sensor is fixed to the outer wall of the combustion furnace.

[0011] A further improvement is that the air preheating box includes a box body connected to the heat exchange coil and a box cover connected to the smoke exhaust pipe, a smoke filter assembly is embedded on one side of the box body close to the box cover, and the inner walls of the box body and the box cover are symmetrically fixed with limit blocks adapted to the smoke filter assembly.

[0012] A further improvement is that a water inlet pipe is fixed to the side of the top of the heat exchange box close to the air preheating box, a water outlet pipe is fixed to the side wall of the heat exchange box away from the air preheating box, and a conical shielding cover is fixed to the top of the discharge pipe through a support.

[0013] A further improvement is that a support column is symmetrically fixed to the bottom of the combustion furnace, a base is fixed to the bottom of the support column, the premixing box is fixed to the top of the base, a mounting block is symmetrically fixed to the outer wall of the base, and mounting bolts are threaded through the mounting block.

[0014] The beneficial effects of the present invention are as follows: by arranging a premixing box below the combustion furnace and arranging a gas mixing mechanism driven by a motor inside the premixing box, the air and hydrogen can be fully mixed before combustion, and deep hydrogen doping can be achieved, thereby ensuring the uniformity and completeness of subsequent combustion in the combustion furnace, greatly reducing the generation of nitrogen oxides, and being more environmentally friendly. By arranging an air preheating box and a heat exchange box at the top of the combustion furnace, not only can the waste heat of the flue gas be used to heat the water, but the air can also be preheated before mixing, thereby increasing the initial temperature of the mixed gas, reducing the ignition point of the fuel, accelerating the reaction speed, and significantly improving the combustion efficiency. The heat recovery efficiency can be improved by utilizing the dual recovery method of the waste heat of the flue gas, and the heat in the flue gas can be fully and efficiently recovered, which is more energy-saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a front view of the present invention;

[0016] Figure 2 is a front cross-sectional view of the present invention;

[0017] Figure 3 The present invention Figure 2 A in the enlarged view;

[0018] Figure 4 It is a top sectional view of the gas mixing mechanism of the present invention.

[0019] Among them: 1. Combustion furnace; 2. Premixing box; 3. Hydrogen injection pipe; 4. Air injection pipe; 5. Motor; 6. First gas pipeline; 7. Second gas pipeline; 8. Third gas pipeline; 9. Ignition needle; 10. Steam water tank; 11. Steam output pipe; 12. Smoke exhaust pipe; 13. Air preheating box; 14. Blower; 15. Preheating coil; 16. Return air pipe; 17. Heat exchange box; 18. Heat exchange coil; 19. Discharge pipe; 20. , rotating shaft; 21, arc-shaped stirring plate; 22, connecting rod; 23, water supply pipe; 24, drain pipe; 25, impurity filter; 26, temperature sensor; 27, liquid level sensor; 28, display screen; 29, water inlet pipe; 30, water outlet pipe; 31, conical shielding cover; 32, supporting column; 33, base; 34, mounting block; 1301, box body; 1302, box cover; 1303, flue gas filter assembly; 1304, limit block. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Deep hydrogen blending refers to the addition of a certain proportion of hydrogen into natural gas, using the high combustion rate and low pollutant emission characteristics of hydrogen to improve combustion performance. Low-NOx combustion compact condensing boilers based on deep hydrogen blending can significantly reduce nitrogen oxide emissions and achieve environmental protection and energy conservation by deeply blending hydrogen into natural gas and using full premixed combustion and condensation technology. At present, low-NOx combustion compact condensing boilers based on deep hydrogen blending have shown great potential in reducing nitrogen oxide emissions, improving thermal efficiency and energy conservation and environmental protection, but related technologies are still in the early stages.

[0022] according to Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, this embodiment provides a compact condensing boiler device with low NOx combustion based on deep hydrogen doping, including a combustion furnace 1 for providing a combustion space for mixed fuel gas and a premixing box 2 located below the combustion furnace 1, the premixing box 2 is used to provide a mixing space for hydrogen and air, a hydrogen injection pipe 3 is fixed to the left side wall of the premixing box 2 and connected to an external hydrogen storage device through the hydrogen injection pipe 3, an air injection pipe 4 is fixed to the right side wall of the premixing box 2, a gas flow control valve is fixed on both the hydrogen injection pipe 3 and the air injection pipe 4, a motor 5 is fixed to the top of the premixing box 2 by bolts, a gas mixing mechanism for fully premixing hydrogen and air is provided inside the premixing box 2 to achieve deep hydrogen doping, and the gas mixing mechanism is driven and operated by the motor 5, by arranging the premixing box 2 below the combustion furnace 1, and arranging the gas mixing mechanism driven and operated by the motor 5 inside the premixing box 2, so that the air and hydrogen can be fully mixed before combustion;

[0023] A first gas pipe 6 is fixed to the top of the premixing box 2, an electronic control valve is fixed to the first gas pipe 6, a second gas pipe 7 is fixed to the top of the first gas pipe 6, a third gas pipe 8 is fixed to the second gas pipe 7, the top of the third gas pipe 8 is an air outlet and penetrates into the combustion furnace 1, and is used to inject mixed fuel gas into the combustion furnace 1, an ignition needle 9 is fixed at the bottom of the combustion furnace 1, and is used to ignite the mixed fuel gas, a steam water tank 10 for storing water to be heated is fixed to the top of the combustion furnace 1 through bolts, and steam output pipes 11 for high-temperature steam discharge are fixed to the front and rear side walls of the steam water tank 10, and the output end air outlet of the steam output pipe 11 penetrates to the outside of the combustion furnace 1 and is connected to external equipment that requires high-temperature steam through pipelines;

[0024] A smoke exhaust pipe 12 is fixed on the right side of the top of the combustion furnace 1. The smoke exhaust pipe 12 has an exhaust fan inside to improve the smoke exhaust efficiency. The end of the smoke exhaust pipe 12 away from the combustion furnace 1 is connected to an air preheating box 13 for preheating air. A blower 14 is fixed to the top of the air preheating box 13 by bolts. A preheating coil 15 is fixed to the output end of the blower 14. The preheating coil 15 is spirally distributed on the inner wall of the air preheating box 13. The output end of the preheating coil 15 passes through the outside of the air preheating box 13 and is fixed with a return air pipe 16. The other end of the return air pipe 16 is connected to the air injection pipe 4. The left side of the air preheating box 13 is provided with a A heat exchange box 17 is provided, and a heat exchange coil 18 is fixed inside the heat exchange box 17. The input end of the heat exchange coil 18 passes through the outside of the heat exchange box 17 and is connected to the air preheating box 13. The output end of the heat exchange coil 18 passes through the outside of the air preheating box 13 and is fixed with an exhaust pipe 19 so that the flue gas can be discharged to the outside. By arranging the air preheating box 13 and the heat exchange box 17 at the top of the combustion furnace 1, not only can the waste heat of the flue gas be used to heat the water, but also the air can be preheated before mixing, thereby increasing the initial temperature of the mixed gas, reducing the ignition point of the fuel, accelerating the reaction speed, and significantly improving the combustion efficiency. In addition, the overall structure of the device is compact and does not occupy a large space.

[0025] The gas mixing mechanism includes a rotating shaft 20 and an arc-shaped stirring plate 21, wherein the rotating shaft 20 is rotatably connected to the inside of the premixing box 2 through a bearing, and the arc-shaped stirring plates 21 are provided with four groups and are symmetrically distributed on the periphery of the rotating shaft 20. Connecting rods 22 are symmetrically fixed between the arc-shaped stirring plates 21 and the rotating shaft 20 to support the arc-shaped stirring plates 21. The rotating shaft 20 is driven by a motor 5 to drive the arc-shaped stirring plates 21 to rotate, so as to utilize a mechanical stirring swirl to fully mix the hydrogen and air before entering the combustion chamber.

[0026] Two groups of first gas pipes 6 are provided and symmetrically fixed on the left and right sides of the top of the premixing box 2. The third gas pipe 8 is equidistantly fixed on the top of the second gas pipe 7. The ignition needles 9 are equidistantly distributed inside the combustion furnace 1 and correspond to the positions of the third gas pipes 8. The combustion distribution is uniform through the equidistantly distributed third gas pipes 8 and ignition needles 9.

[0027] A water supply pipe 23 is fixed to the left side wall of the steam water tank 10, and a drain pipe 24 is fixed to the right side wall of the steam water tank 10. Both the water supply pipe 23 and the drain pipe 24 extend to the outside of the combustion furnace 1 and are used for water in and out of the steam water tank 10. Liquid flow control valves are fixed on the water supply pipe 23 and the drain pipe 24 to facilitate the control of water in and out. An impurity filter net 25 is fixed between the lower part of the outer wall of the steam water tank 10 and the inner wall of the combustion furnace 1 to perform preliminary filtering of impurities in the combustion flue gas.

[0028] A temperature sensor 26 is fixed by bolts on the left side of the top of the steam water tank 10, which is used to monitor the temperature inside the steam water tank 10 in real time. A liquid level sensor 27 is fixed by bolts on the right side of the top of the steam water tank 10, and the detection end of the liquid level sensor 27 extends to the bottom end of the steam water tank 10, which is used to monitor the remaining water in the steam water tank 10 in real time. A display screen 28 is fixed on the outer wall of the combustion furnace 1. The temperature sensor 26 and the liquid level sensor 27 are both connected to the PLC control system of the device, and are used to send the monitored data to the display screen 28 for display.

[0029] The air preheating box 13 is composed of a box body 1301 and a box cover 1302, which are fixed by bolts, wherein the box body 1301 is connected to the heat exchange coil 18, and the box cover 1302 is connected to the smoke exhaust pipe 12. A smoke filter assembly 1303 for secondary filtering of smoke is embedded on one side of the box body 1301 close to the box cover 1302, and the inner walls of the box body 1301 and the box cover 1302 are symmetrically fixed with limit blocks 1304 adapted to the smoke filter assembly 1303. When the box body 1301 and the box cover 1302 are fixed by a butt joint, the smoke filter assembly 1303 is limited and fixed by the limit blocks 1304.

[0030] A water inlet pipe 29 is fixed on the right side of the top of the heat exchange box 17, which is connected to the external cold water supply equipment. A water outlet pipe 30 is fixed on the right side wall of the heat exchange box 17, which is used to transport hot water to external equipment that needs hot water. A conical shielding cover 31 is fixed on the top of the discharge pipe 19 through a support member, which has a certain shielding effect on the top opening of the discharge pipe 19.

[0031] Support columns 32 are welded and fixed at the four corners of the bottom end of the combustion furnace 1, and a base 33 is welded and fixed to the bottom ends of the four groups of support columns 32. The premixing box 2 is fixed to the top of the base 33 by bolts, and the outer wall of the base 33 is symmetrically fixed with mounting blocks 34. The mounting blocks 34 are threaded with mounting bolts to facilitate the fixed installation of the base 33.

[0032] When the low NOx combustion compact condensing boiler device based on deep hydrogen doping is actually used, the hydrogen injection pipe 3 is connected to the external hydrogen storage device, and a certain amount of hydrogen is injected into the premixing box 2. At the same time, the blower 14 is started to inject air into the premixing box 2 through the preheating coil 15, the return air pipe 16 and the air injection pipe 4. The motor 5 is then used to drive the gas mixing mechanism in the premixing box 2 to operate, and the hydrogen and air in the premixing box 2 are fully mixed before combustion. The mixed fuel gas is injected into the combustion furnace 1 through the first gas pipeline 6, the second gas pipeline 7 and the third gas pipeline 8. At the same time, the ignition needle 9 is turned on for ignition, so that the fuel gas burns and the water in the steam water tank 10 is heated. The water in the steam water tank 10 is heated at high temperature to generate high-temperature steam, which is transported to the external equipment that needs high-temperature steam through the steam output pipe 11, and the high-temperature flue gas generated by the combustion in the combustion furnace 1 enters the air preheating box 13 through the flue gas exhaust pipe 12, and performs preliminary heat exchange with the air in the preheating coil 15, so that the air is preheated before entering the premixing box 2, and then the air is injected into the heat exchange coil 18 in the heat exchange box 17 from the air preheating box 13, and performs secondary heat exchange with the water in the heat exchange box 17, and the flue gas that has been cooled twice is discharged to the outside from the exhaust pipe 19, and the heated water is discharged from the heat exchange box 17 and supplied to the outside where hot water is needed.

[0033] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping, comprising a combustion furnace (1), characterized in that: A premixing box (2) is provided below the combustion furnace (1), and a hydrogen injection pipe (3) and an air injection pipe (4) are fixed on both sides of the premixing box (2), and a gas mixing mechanism driven by a motor (5) is provided inside the premixing box (2). The top of the premixing box (2) is connected to a second gas pipe (7) via a first gas pipe (6), and a third gas pipe (8) is fixed on the second gas pipe (7) and penetrates into the combustion furnace (1). An ignition needle (9) adapted to the third gas pipe (8) is fixed below the inside of the combustion furnace (1), and a steam water tank (10) is fixed at the top of the inside of the combustion furnace (1), and steam output pipes (11) that penetrate into the outside of the combustion furnace (1) are fixed on both the front and rear side walls of the steam water tank (10). 11), the top of the combustion furnace (1) is connected to an air preheating box (13) through a smoke exhaust pipe (12), a blower (14) is fixed to the top of the air preheating box (13), a preheating coil (15) located inside the air preheating box (13) is fixed to the output end of the blower (14), a return air pipe (16) is connected between the preheating coil (15) and the air injection pipe (4), a heat exchange box (17) is provided on the side of the air preheating box (13) away from the smoke exhaust pipe (12), a heat exchange coil (18) connected to the air preheating box (13) is fixed inside the heat exchange box (17), and the output end of the heat exchange coil (18) passes through the outside of the air preheating box (13) and is fixed to an exhaust pipe (19).

2. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping according to claim 1, characterized in that: The gas mixing mechanism comprises a rotating shaft (20) rotatably connected to the interior of the premixing box (2) and arc-shaped stirring plates (21) symmetrically distributed on the periphery of the rotating shaft (20), and connecting rods (22) are symmetrically fixed between the arc-shaped stirring plates (21) and the rotating shaft (20).

3. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping according to claim 1, characterized in that: Gas flow control valves are fixed on the hydrogen injection pipe (3) and the air injection pipe (4); the first gas supply pipe (6) is symmetrically fixed to the top of the premixing box (2); an electronic control valve is fixed on the first gas supply pipe (6); the third gas supply pipe (8) is equidistantly fixed to the top of the second gas supply pipe (7); and the ignition needles (9) are equidistantly distributed inside the combustion furnace (1) and correspond to the positions of the third gas supply pipe (8).

4. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping according to claim 1, characterized in that: A water supply pipe (23) and a drain pipe (24) penetrating to the outside of the combustion furnace (1) are fixed to the two side walls of the steam water tank (10), and a liquid flow control valve is fixed to the water supply pipe (23) and the drain pipe (24). An impurity filter (25) is fixed between the lower part of the outer wall of the steam water tank (10) and the inner wall of the combustion furnace (1).

5. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping according to claim 1, characterized in that: A temperature sensor (26) and a liquid level sensor (27) are fixed to the top of the steam water tank (10), respectively; a detection end of the liquid level sensor (27) extends to the bottom of the steam water tank (10); and a display screen (28) electrically connected to the temperature sensor (26) and the liquid level sensor (27) is fixed to the outer wall of the combustion furnace (1).

6. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping according to claim 1, characterized in that: The air preheating box (13) comprises a box body (1301) connected to a heat exchange coil (18) and a box cover (1302) connected to a smoke exhaust pipe (12); a smoke filter assembly (1303) is embedded in the box body (1301) on one side close to the box cover (1302); and limit blocks (1304) adapted to the smoke filter assembly (1303) are symmetrically fixed to the inner walls of the box body (1301) and the box cover (1302).

7. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping according to claim 1, characterized in that: A water inlet pipe (29) is fixed to a side of the top of the heat exchange box (17) close to the air preheating box (13), a water outlet pipe (30) is fixed to a side wall of the heat exchange box (17) away from the air preheating box (13), and a conical shielding cover (31) is fixed to the top of the discharge pipe (19) via a support.

8. A compact condensing boiler device with low NOx combustion based on deep hydrogen doping according to claim 1, characterized in that: A support column (32) is symmetrically fixed to the bottom end of the combustion furnace (1), a base (33) is fixed to the bottom end of the support column (32), the premixing box (2) is fixed to the top of the base (33), a mounting block (34) is symmetrically fixed to the outer wall of the base (33), and a mounting bolt is threaded through the mounting block (34).

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