CN112460568A - Full premix water-cooling gas boiler of U-shaped tubular structure - Google Patents
Full premix water-cooling gas boiler of U-shaped tubular structure Download PDFInfo
- Publication number
- CN112460568A CN112460568A CN202011323855.XA CN202011323855A CN112460568A CN 112460568 A CN112460568 A CN 112460568A CN 202011323855 A CN202011323855 A CN 202011323855A CN 112460568 A CN112460568 A CN 112460568A
- Authority
- CN
- China
- Prior art keywords
- water
- heat exchanger
- cooled
- combustion head
- upper header
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B1/00—Methods of steam generation characterised by form of heating method
- F22B1/22—Methods of steam generation characterised by form of heating method using combustion under pressure substantially exceeding atmospheric pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B31/00—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus
- F22B31/08—Installation of heat-exchange apparatus or of means in boilers for heating air supplied for combustion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H1/00—Water heaters, e.g. boilers, continuous-flow heaters or water-storage heaters
- F24H1/22—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating
- F24H1/40—Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating with water tube or tubes
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
- F24H9/00—Details
- F24H9/18—Arrangement or mounting of grates or heating means
- F24H9/1809—Arrangement or mounting of grates or heating means for water heaters
- F24H9/1832—Arrangement or mounting of combustion heating means, e.g. grates or burners
- F24H9/1836—Arrangement or mounting of combustion heating means, e.g. grates or burners using fluid fuel
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Sustainable Energy (AREA)
- Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
Abstract
The invention discloses a full-premixing water-cooled gas boiler with a U-shaped pipe structure, which comprises a water-cooled burner and a water-cooled heat exchanger which are coaxially arranged, wherein the water-cooled burner is internally provided with a premixer and a water-cooled burner head, a water outlet of the water-cooled burner is communicated with a water inlet of the water-cooled heat exchanger, and the premixer is communicated with a gas inlet of the water-cooled burner head; the water-cooled combustion head comprises a combustion head water-cooled tube bundle and a combustion head upper header, the combustion head upper header is nested inside and outside, and two ends of the combustion head water-cooled tube bundle are respectively communicated with the combustion head upper header on the inner side and the outer side; the water inlet of the upper header of the combustion head is communicated with boiler feed water, and a single water-cooling pipe of the water-cooling pipe bundle is U-shaped; the inner side of the water-cooled combustion head is provided with a flow equalizing pore plate, and the ignition gun is arranged on the outer side of the water-cooled combustion head; the flue gas flows out of the water-cooled combustion head and then uniformly flows to each water-cooled tube bundle in the water-cooled heat exchanger, then flows downwards to the dew bearing disc from the gap between the outer ring water-cooled tube bundle and the furnace wall and is discharged through the chimney, the heat exchange capacity is greatly improved, and the safe and stable operation of the boiler is facilitated.
Description
Technical Field
The invention belongs to the field of safe and stable low-nitrogen combustion of natural gas, burners and boiler design, and particularly relates to a full-premix water-cooling gas boiler with a U-shaped pipe structure.
Background
The combustors are classified into diffusion combustors, partial premix combustors, and full premix combustors according to whether or not they are mixed before combustion and the degree of mixing. The diffusion type combustor is simple in structure, safe and reliable in operation, free of backfire risk, long in flame and large in combustion space; the partial premixing type combustor is mainly used for the traditional small wall-mounted gas boiler, and has a heavy structure when the heat load is large; the full-premixing gas combustion mode has the advantages of high combustion strength, short flame, small combustion equipment volume, uniform combustion, no generation of a local high-temperature area, obvious advantages in large gas boilers, high combustion temperature and high NOx emission, and can be used for tempering at low load and de-igniting at high load, so that the development of the full-premixing gas combustor in civil and industrial fields is greatly limited. In order to reduce the combustion temperature of the fully premixed burner, thereby reducing the NOx emission and ensuring the complete combustion, a mode of improving the excess air coefficient is mostly adopted, and therefore, the problems of large smoke discharge loss and low boiler efficiency are also generated; in addition, the metal wire mesh gap of the full premix burner is very small, and the problems of blockage and burning are very easy to occur. Therefore, the full-premix water-cooled burner is produced, the traditional burner head is replaced by the water-cooled tube bundle, the temperature of a combustion area is reduced through the water-cooled tube bundle, the NOx emission is reduced, and meanwhile, the occurrence of backfire and misfire is prevented by controlling the tube ring gap. The water-cooled burner is developed rapidly in recent years, but is mostly used for small wall-mounted furnaces, and the water-cooled burner is poor in adaptability to boilers and large in modification workload.
The traditional boiler adopts an upper square header and a lower square header structure and is formed by welding 4 steel plates or an upper half end socket and a lower half end socket and a short cylinder, a straight pipe bundle and the upper header and the lower header are required to be welded, two ends of a straight pipe are required to be necked, the process cost is increased, and welding spots are too many; flue gas after the combustor burning flows to one side water-cooled heat exchanger tube bank among the traditional boiler, flows out round the clearance between outer lane tube bank and brickwork then, and the water-cooled tube bundle temperature distribution of different positions department is extremely inhomogeneous, easily leads to the emergence of accidents such as tube explosion.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides a full-premix water-cooled gas boiler with a U-shaped pipe structure, which reduces the emission of nitrogen oxides on the basis of non-tempering, non-de-ignition and stable combustion and is suitable for old boilers to perform low-nitrogen modification.
In order to achieve the purpose, the invention adopts the technical scheme that: a full-premixing water-cooled gas boiler with a U-shaped pipe structure comprises a water-cooled burner and a water-cooled heat exchanger, wherein the water-cooled burner and the water-cooled heat exchanger are cylindrical, the water-cooled heat exchanger is coaxially arranged on the outer side of the water-cooled burner, a premixer and a water-cooled burner head are arranged in the water-cooled burner, a water outlet of the water-cooled burner is communicated with a water inlet of the water-cooled heat exchanger, and an outlet of the premixer is communicated with a gas inlet of the water; the water-cooled combustion head comprises a combustion head water-cooled tube bundle and two combustion head upper header tanks, the two combustion head upper header tanks are nested inside and outside, and two ends of the combustion head water-cooled tube bundle are respectively communicated with the combustion head upper header tanks on the inner side and the outer side; the water inlet of the combustion head upper header is communicated with boiler feed water, the water outlet of the combustion head upper header is communicated with the water inlet of the water-cooled heat exchanger, and a single water-cooled tube of the combustion head water-cooled tube bundle is U-shaped; the inner side of the water-cooled combustion head is provided with a flow equalizing pore plate which is cylindrical, the top of the flow equalizing pore plate is open, and the bottom of the flow equalizing pore plate is sealed; a gap is arranged between the inner side of the water-cooled combustion head and the flow equalizing pore plate, and the ignition gun is arranged on the outer side of the water-cooled combustion head.
The combustion head water-cooling tube bundle at least comprises two circles of combustion head straight tubes, the clearance of the outer circle of combustion head water-cooling tube bundle in the combustion head water-cooling tube bundle is larger than that of the inner circle of combustion head water-cooling tube bundle, and the adjacent two circles of combustion head straight tubes are arranged in a staggered mode.
The clearance between the inner side of the water-cooled combustion head and the flow equalizing pore plate is 5-10 mm.
The premixer comprises an outer cylinder and an inner cylinder which are coaxially arranged, the outer cylinder is coaxially arranged at the outer side of the inner cylinder, the bottom of the inner cylinder is closed, and a plurality of inner cylinder spray holes are formed in the cylinder wall at the lower part of the inner cylinder; a flow guide channel is arranged between the inner cylinder and the outer cylinder, the flow area of the flow guide channel is gradually reduced from top to bottom, and the air entering an annular space between the outer cylinder and the inner cylinder is guided to the central direction of the outer cylinder by the flow guide channel; the lower part of the inner cylinder is sequentially provided with a rotational flow blade and a despin structure; the despin structure adopts a plurality of flow guide straight plates, and a plurality of airflow channels parallel to the axis of the outer cylinder are formed between the straight plates and the outer cylinder.
20-30 swirl blades are uniformly arranged along the circumferential direction, and the number of the airflow channels is 4-10.
The water-cooled heat exchanger comprises a heat exchanger upper header and a heat exchanger water-cooled tube bundle, the heat exchanger upper header comprises an inner heat exchanger upper header and an outer heat exchanger upper header, and two ends of the heat exchanger water-cooled tube bundle are respectively communicated with the inner heat exchanger upper header and the outer heat exchanger upper header; the upper headers of the inner heat exchanger and the outer heat exchanger are concentrically arranged, and a single water-cooling pipe of a water-cooling pipe bundle of the heat exchanger is U-shaped; the upper header of the heat exchanger on the inner side is provided with a water inlet of the heat exchanger, and the upper header of the heat exchanger on the outer side is provided with a water outlet of the heat exchanger.
The water-cooled heat exchanger comprises a heat exchanger upper header, a heat exchanger lower header and a heat exchanger water-cooled tube bundle, wherein one end of the heat exchanger water-cooled tube bundle is connected with the heat exchanger upper header, and the other end of the heat exchanger water-cooled tube bundle is connected with the heat exchanger lower header; the single water-cooling pipe in the heat exchanger water-cooling pipe bundle comprises three heat exchanger straight pipes, and two adjacent heat exchanger straight pipes are connected through a bent pipe; the bottom of the lower heat exchanger header is provided with a heat exchanger water inlet, and the top of the upper heat exchanger header is provided with a heat exchanger water outlet.
The top and bottom horizontal directions of the water-cooled combustion head and the water-cooled heat exchanger are provided with a flue gas baffle and a heat insulation layer, the heat insulation layer is arranged on the outer side of the flue gas baffle, and the outer side of the bottom of the water-cooled heat exchanger is provided with a circle of flue gas baffle in the vertical direction.
The condensation heat exchanger is arranged along the circumferential direction of the bottom of the boiler, the dew bearing disc is arranged below the condensation heat exchanger, the chimney of the boiler is arranged below the dew bearing disc, the heights of the dew bearing disc and the chimney are gradually reduced from the periphery to the center, the middle of the dew bearing disc is provided with a hole, and the lowest part of the chimney is provided with a condensate outlet.
The condensing tube of the condensing heat exchanger is U-shaped, the condensing tube of the condensing heat exchanger adopts staggered light tubes, spiral finned tubes, H-shaped finned tubes or pin-fin tubes along the flue gas scouring direction, and the condensing tube adopts a single tube ring, double tube rings, three tube rings or four tube ring structure.
Compared with the prior art, the invention has at least the following beneficial effects:
according to the fully premixed water-cooled gas boiler, flue gas flows out from the water-cooled combustion head at the center and then uniformly flows to each water-cooled tube bundle in the water-cooled heat exchanger, then flows downwards to the dew bearing disc from the gap between the outer water-cooled tube bundle and the boiler wall and is discharged through the chimney, the flow and heat exchange are uniform, the heat exchange capacity is greatly improved, and the safe and stable operation of the boiler is facilitated;
by changing parameters such as the tube bundle gap and the tube bundle size of the water-cooled combustion head, a mixed gas narrow gap flow channel can be formed between the inner ring water-cooled tube bundles of the combustion head, so that tempering is prevented, and combustion is safe; reasonable gaps are controlled between the water-cooled tube bundles on the outer ring of the combustion head to prevent fire dropping and stabilize flame; the flow and heat exchange are uniform, the heat exchange efficiency is high, the exhaust gas temperature of the boiler can be reduced, the boiler efficiency is improved, and the safe and stable operation of the boiler is facilitated;
the combustor is whole cylindrically, inside vertically stretching into furnace, need not to change boiler body tube bank, it is very strong with boiler body tube bank suitability, the first water-cooled tube bank of burning reduces flame root temperature, reduce heating power type nitrogen oxide and discharge, satisfy low nitrogen combustion emission standard, can be used to the low nitrogen of traditional boiler and reform transform, can adapt old and old boiler well and carry out low nitrogen and reform transform, replace traditional diffusion formula and mix formula combustor in advance, reduce NOx and discharge when preventing tempering and taking off a fire.
Furthermore, the boiler feed water firstly passes through the condensing heat exchanger to absorb the waste heat of the flue gas before entering the water-cooled combustion head, so that the flue gas emission temperature is reduced, the heat exchange capacity is greatly improved, and the safe and stable operation of the boiler is facilitated.
Furthermore, the mixer can adapt to the adjustment of a larger proportion and keep good mixing characteristic all the time in the load change range, the flow field is uniformly distributed, the problem of boiler efficiency reduction caused by the adoption of a high excess air coefficient in the full premixed combustion is avoided, and the combustion efficiency is ensured.
Furthermore, two adjacent water-cooling straight pipes are connected by adopting a bent pipe for transition, the cost of forming and welding the upper header steel plate and the lower header steel plate is saved or the lower header is directly saved, the pipe orifice welding workload is reduced by 50%, and in addition, the sizes of the upper header steel plate and the lower header steel plate can be reduced, so that the steel loss is reduced.
Drawings
FIG. 1 is a schematic view of the overall structure of the boiler of the present invention.
FIG. 2 is a schematic view of the premixer structure of the water-cooled burner of the present invention.
FIG. 3a is a schematic view of the arrangement of the lateral swirl type swirl vanes of the present invention.
FIG. 3b is a schematic view of the arrangement of the swirl vanes in the lower swirl mode of the present invention.
FIG. 4 is a schematic view of a flow equalizing pore plate structure of the water-cooled burner of the present invention.
FIG. 5 is a schematic view of a burner head structure of the water-cooled burner of the present invention.
FIG. 6a is a schematic view of a single tube bundle of a water-cooled heat exchanger according to the present invention.
Fig. 6b is a schematic diagram of a single tube bundle of three water-cooling straight tubes of the water-cooling heat exchanger according to the present invention.
Fig. 6c is a schematic diagram of a variation of the water-cooled heat exchanger of the present invention to the single-tube bundle structure shown in fig. 6 b.
Fig. 7 is a schematic diagram of a variation of the water-cooled heat exchanger of the present invention to the tube bundle structure of fig. 6 b.
Fig. 8 is a schematic structural diagram of a condensing heat exchanger according to the present invention.
FIG. 9 is a flow chart of boiler flue gas and water according to the present invention.
Wherein 1: water-cooled burner, 11: drum air distribution device, 111: blower, 112: gas cylinder, 113: dispensing housing, 12: premixer, 121: outer cylinder, 122: flow guide cone, 123: annular piece, 124: swirl vanes, 125: racemic structure, 126: inner cylinder, 1261: inner cylinder nozzle, 13: water-cooled burner, 131: flow equalization orifice plate, 132: burner water inlet, 133: header on burner, 134: burner water-cooled tube bundle, 1341: burner straight tube, 1342: burner elbow, 135: burner water outlet, 136: ignition gun, 137: header under burner, 2: water-cooled heat exchanger, 21: heat exchanger water inlet, 22: header on the heat exchanger, 23: heat exchanger water-cooled tube bundle, 231: heat exchanger straight tube, 232: heat exchanger elbow, 24: heat exchanger water outlet, 25: heat exchanger lower header, 26: condensation heat exchanger, 3: other boiler components, 31: boiler outer casing, 32: flue gas baffle, 33: insulation layer, 34: dew-bearing plate, 35: condensate drain, 36: chimney, 37: boiler support, 38: explosion vent, 39: the upper and lower expansion sliding circumferential limit bracket.
Detailed Description
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, a fully premixed water-cooled gas boiler with a U-shaped tube structure comprises a "boiler" and a "furnace" and other boiler components 3, wherein the "boiler" refers to a water-cooled heat exchanger 2 wrapped outside the "furnace", and the water-cooled heat exchanger 2 comprises a plurality of heat exchanger water-cooled tube bundles; the furnace is a water-cooled combustor 1 which is wrapped inside an external water-cooled heat exchanger 2 and is used for central air intake, the water-cooled combustor 1 is integrally cylindrical, and the water-cooled combustor 1 comprises a plurality of combustion head water-cooled tube bundles; the single tube bundle of combustion head water-cooling tube bank and heat exchanger water-cooling tube bank is the U-shaped water-cooling pipe, and water-cooling combustor 1 and the water-cooling heat exchanger 2 of outer lane have similar overall structure.
The premixer 12 comprises an outer cylinder 121, a flow guide cone 122, an annular sheet 123, swirl blades 124, a despin structure 125 and an inner cylinder 126, wherein the outer cylinder 121 is coaxially arranged at the outer side of the inner cylinder 126, a flow guide channel is arranged between the inner cylinder 126 and the outer cylinder 121, the flow guide channel gradually reduces in flow area from top to bottom, and the flow guide channel guides air entering an annular space between the outer cylinder 121 and the inner cylinder 126 to the central direction of the outer cylinder; the lower section of the inner cylinder 126 is provided with a plurality of inner cylinder spray holes 1261, and the inner cylinder spray holes 1261 are positioned in the height range covered by the diversion cone 122; a diversion cone 122 is arranged between the inner cylinder 126 and the outer cylinder 121, and the diameter of the top surface circle of the diversion cone 122 is larger than that of the bottom surface circle thereof; the top end of the guide cone 122 is connected with the inner wall of the outer cylinder 126 in a circle, and the bottom surface of the guide cone 122 is suspended; the swirl vanes 124 and the despin structure 125 are arranged below the inner barrel 126;
the water-cooled combustion head 13 comprises a flow equalizing pore plate 131, a combustion head water inlet 132, a combustion head upper header 133, a combustion head water-cooled tube bundle 134, a combustion head water outlet 135 and an ignition gun 136;
the burner head water-cooling tube bundle 134 comprises a burner head straight tube 1341 and a burner head bent tube 1342, and the burner head straight tube 1341 and the burner head bent tube 1342 are spliced to form a U-shaped water-cooling tube;
the water-cooled heat exchanger 2 comprises a heat exchanger water inlet 21, a heat exchanger upper header 22, a heat exchanger water-cooled tube bundle 23, a heat exchanger water outlet 24, a heat exchanger lower header 25 and a condensing heat exchanger 26; the heat exchanger water inlet 21, the heat exchanger lower header 25, the heat exchanger water cooling tube bundle 23, the heat exchanger upper header 22 and the heat exchanger water outlet 24 are communicated in sequence; the heat exchanger water-cooling tube bundle 23 comprises a heat exchanger straight tube 231 and a heat exchanger bent tube 232, the heat exchanger bent tube 232 is connected with two adjacent heat exchanger straight tubes, and the two heat exchanger straight tubes are spliced to form a U-shaped bent tube.
The other boiler components 3 comprise a boiler shell 31, a smoke baffle 32, a heat insulation layer 33, a dew bearing disc 34, a condensate outlet 35, a chimney 36, a boiler support 37, an explosion door 38, an up-down expansion sliding circumferential limiting support 39 and the like. The chimney 36 is arranged at the bottom of the boiler, and a condensate outlet 35 is formed at the lowest part of the bottom of the chimney; a flue gas baffle 32 is arranged below the water-cooled burner 1 and the water-cooled heat exchanger 2, a boiler support 37 is arranged below the boiler shell 31, and an explosion door 38 is arranged at the middle lower part of the boiler shell 31; the limiting bracket 39 is arranged at the bottom of the water-cooling heat exchanger 2, and the limiting bracket 39 is used for limiting the circumferential direction of the heat exchanger water-cooling tube bundle 23; the limiting bracket 39 is connected with the heat exchanger elbow, can slide up and down, has unchanged position in the horizontal direction, and is used for limiting the circumferential direction of the heat exchanger water cooling tube bundle 23.
Referring to fig. 1 and 2, the gas adopts a central air inlet mode, and the air and the gas adopt a post-mixing mode; the air blowing and distributing device 11 comprises an air blower 111, an air distributing cylinder 112 and a distribution shell 113, the air blower 111, the air distributing cylinder 112 and the distribution shell 113 are sequentially connected, the air blower 111 meets the requirements of static electricity prevention and explosion prevention, air blown in by the air blower 111 is sent into the distribution shell 113 through the air distributing cylinder 112, the distribution shell 113 is communicated with the top of an outer cylinder 121, the outer cylinder 121 is a cylindrical cylinder, the bottom of the top is open, the air enters into an annular space at the top of the outer cylinder 121 and the inner cylinder 126 from the distribution shell 113 to form an air inlet, the air enters from the air inlet and then flows downwards along the annular space between the inner cylinder 126 and the outer cylinder 121, a guide cone 122 is arranged between the inner cylinder 126 and the outer cylinder 121, the guide cone 122 is a part of an inverted cone-shaped curved plate, the flow area of the guide cone 122 is gradually reduced from top to bottom, the upper part of the guide cone, when the air flows through the diversion cone 122, the direction changes and the air leans against the wall surface of the inner cylinder 126; the inner cylinder 126 is a cylindrical cavity, the top of the inner cylinder is open, the bottom of the inner cylinder is closed, the top of the inner cylinder 126 is used as a fuel gas inlet to be connected with a fuel gas pipeline, a plurality of inner cylinder spray holes 1261 are uniformly distributed on the wall surface of the lower part of the inner cylinder 126, the inner cylinder spray holes 1261 are positioned in the middle of the guide cone 122, the inner cylinder spray holes 1261 are circular, square, triangular, quincunx or rhombic, the combination of the different shapes can be adopted, and the inner cylinder spray holes 126; the gas enters from the top of the inner cylinder 126 and then flows downwards along the inner cylinder 126, and is sprayed out from the inner cylinder spray holes 1261 to form inclined cross jet flow mixing with the incoming air passing through the guide cone 122.
Referring to fig. 2, fig. 3a and fig. 3b, a circle of swirl blades 124 are welded on the outer wall of an inner cylinder 126 below a guide cone 122, the outer ends of the swirl blades 124 are welded on the inner wall of an outer cylinder 121, and 20-30 swirl blades 124 are uniformly arranged along the circumferential direction, so that the fuel gas and the air are mixed and then rotated (side swirl); as an alternative embodiment, an annular sheet 123 can be welded at the bottom of the inner cylinder 126, the diameter of the outer wall of the annular sheet 123 is smaller than or equal to that of the outer wall of the inner cylinder 126, one end of a swirl blade 124 is welded on the outer wall of the annular sheet 123, the other end of the swirl blade 124 is welded on the inner wall of the outer cylinder 121, 20-30 swirl blades 124 are uniformly arranged along the circumferential direction, preferably, the size of the annular sheet 123 is smaller than that of the inner cylinder 126, and at this time, the size of the swirl blade 124 is also larger, and the swirl. A despin structure 125 is arranged at a preset distance below the swirl vanes 124, the despin structure 125 is welded on the inner wall of the outer cylinder 121, the despin structure 125 can be radial, such as a cross plate or a Chinese character 'mi' plate, and the despin structure 125 can also be flat, such as a Chinese character 'chuan' plate; the racemic structure 125 is preferably radial, and the number of the subareas is 4-10, and more subareas are preferred.
Referring to fig. 1 and 4, a flow equalizing pore plate 131 is welded below the outer cylinder 121, the diameter and thickness of the flow equalizing pore plate 131 are the same as those of the outer cylinder 121, the lower part of the flow equalizing pore plate 131 is equal to the bottom of a combustion head elbow 1342, a bottom plate is adopted to seal the lower part of the flow equalizing pore plate 131, a gap between the bottom of the flow equalizing pore plate 131 and a combustion head water-cooling tube bundle 134 is sealed, short-circuit of mixed gas is prevented from directly flowing out of the lower part of the flow equalizing pore plate 131, circular, square, triangular, quincunx or rhombic flow equalizing pores are uniformly distributed on the flow equalizing pore plate 131, or the flow equalizing pore plate 131 is.
A single water-cooling pipe adopts a U shape, namely a single water-cooling pipe bundle at least comprises two water-cooling straight pipes, two adjacent water-cooling straight pipes are connected by adopting a bent pipe, and the angle of the bent pipe is more than or equal to 180 degrees.
Referring to fig. 5 and fig. 6a, 6b, and 6c, the arrangement of the combustion head water-cooling tube bundle and the heat exchanger water-cooling tube bundle is as follows (the reference in the drawings takes the heat exchanger water-cooling tube bundle as an example, and the combustion head water-cooling tube bundle corresponds to it):
as a preferred embodiment: specifically, two circles of vertical straight pipe bundles are connected with 180-degree elbows to form a single U-shaped structure, two annular combustion head upper header boxes 133 are connected above two circles of combustion head straight pipes 1341, the combustion head upper header boxes 133 are arranged in a high-low mode, 2-4 water pipes are connected to the combustion head upper header box 133 on the inner side to serve as a combustion head water inlet 132, and 2-4 water pipes are connected to the combustion head upper header box 133 on the outer side to serve as a combustion head water outlet 135. The water outlet 135 of the combustion head is connected with the upper header 22 of the inner side heat exchanger and then flows to the upper header 22 of the outer side heat exchanger along the water cooling tube bundle 23 of the heat exchanger to be led out; two ring heat exchanger upper header 22 are connected to two circles heat exchanger straight tube 231 tops, and header 22 is arranged one high one low on the heat exchanger, and 2 ~ 4 water pipes are connected as heat exchanger water inlet 21 on the heat exchanger of inboard, and header 22 connects 2 ~ 4 water pipes as heat exchanger delivery port 24 on the heat exchanger of outside. The combustion head water outlet 135 is connected with the inner side heat exchanger upper header 22, and then flows to the heat exchanger upper header 22 along the heat exchanger water-cooling tube bundle 23 to be led out.
As an optional embodiment, the heat exchanger water-cooling tube bundle 23 and the combustion head water-cooling tube bundle both adopt three circles of vertical straight tube bundles, two adjacent water-cooling straight tubes of the same tube bundle are connected through 180-degree bent tubes to form a double-U-shaped structure, two ends of the double-U-shaped tube are respectively connected with an annular combustion head upper header 133 and a combustion head lower header 137, the combustion head upper header 133 is positioned at the outer side, the combustion head lower header 137 is positioned at the inner side, 2-4 water tubes are connected below the combustion head lower header 137 to serve as combustion head water inlets 132, 2-4 water tubes are connected outside the combustion head upper header 133 to serve as combustion head water outlets 135, and the combustion head water outlets 135 are connected with the inner side heat exchanger lower header 25 and then flow to the outer side heat exchanger upper header 22 along the heat exchanger water-cooling tube bundle 23; two adjacent circles of tube bundles are connected through 180-degree bent tubes (namely two adjacent water-cooled straight tubes in the same water-cooled tube bundle are connected through 180-degree bent tubes) to form a double-U-shaped structure, two ends of each double-U-shaped tube are respectively connected with an annular upper heat exchanger header 22 and a lower heat exchanger header 25, the upper heat exchanger header 22 is positioned on the outer side, the lower heat exchanger header 25 is positioned on the inner side, 2-4 water tubes are connected below the lower heat exchanger header 25 to serve as a water inlet 21 of the heat exchanger, 2-4 water tubes are connected on the outer side of the upper heat exchanger header 22 to serve as a water outlet 24 of the heat exchanger, a water outlet 135 of a combustion head is connected with the lower heat exchanger header 25, then flows to the upper heat exchanger header 22 on the outer side along the water-; the outlet of the condensing heat exchanger 26 is communicated with the water inlet 132 of the combustion head through a pipeline.
Referring to fig. 7, as another alternative embodiment, the two side straight tube bundles are vertical, the middle straight tube bundle is inclined by a set angle, two adjacent circles of burner straight tubes 1341 are connected by a burner elbow 1342 of more than 180 ° to form a double U-shaped structure, so as to form a compact heat exchange structure, two ends of the double U-shaped tube are respectively connected to an annular burner upper header 133 and a burner lower header 137, the burner upper header 133 is located at the outer side, the burner lower header 137 is located at the inner side, 2 to 4 water tubes are connected below the burner lower header 137 to serve as burner water inlets 132, the burner upper header 133 is connected to 2 to 4 water tubes to serve as burner water outlets 135, the burner water outlets 135 are connected to the inner side heat exchanger lower header 25, and then flow to the outer side heat exchanger upper header 22 along the heat exchanger water-cooling tube bundle 23; two adjacent circles of heat exchanger straight pipes 231 are connected through a heat exchanger bent pipe 232 with an angle larger than 180 degrees to form a double-U-shaped structure, so that a compact heat exchange structure is formed, two ends of the double-U-shaped pipe are respectively connected with an annular heat exchanger upper header 22 and a heat exchanger lower header 25, the heat exchanger upper header 22 is positioned on the outer side, the heat exchanger lower header 25 is positioned on the inner side, 2-4 water pipes are connected below the heat exchanger lower header 25 to serve as a heat exchanger water inlet 21, the heat exchanger upper header 22 is connected with 2-4 water pipes to serve as a heat exchanger water outlet 24, a combustion head water outlet 135 is connected with the inner side heat exchanger lower header 25, and then the double-U-shaped pipe flows to the outer; the outlet of the condensing heat exchanger 26 is communicated with the water inlet 132 of the combustion head through a pipeline.
The sections of the combustion head upper header 133, the combustion head lower header 137, the heat exchanger upper header 22 and the heat exchanger lower header 25 of the three schemes can be circular, square or the combination of the circular and the square; the volumes of the water outlet header of the water-cooled combustion head 13 and the water outlet header of the water-cooled heat exchanger 2 are respectively equal to or larger than the volumes of the water inlet headers; the number of turns of the tube bundle arranged by the internal water-cooled burner 1 and the external water-cooled heat exchanger 2 can be the same or different, the bottom of the upper header 22 of the heat exchanger and the bent tube 232 of the heat exchanger are provided with a flue gas baffle 32 and a heat insulation layer 33, the flue gas baffle 32 is made of refractory materials, and the bottom of the straight tube 231 of the external heat exchanger is also provided with the flue gas baffle 32 at the bent position, so that the flue gas is prevented from directly flowing out from the lower part in a.
A 510 +/-30 mm gap is formed between the combustion head straight pipe 1341 of the inner ring and the flow equalizing pore plate 131, the diameters and the heights of the two adjacent circles of combustion head water-cooling pipe bundles 134 or the heat exchanger water-cooling pipe bundles 23 are equal, and the number of the pipes is the same and the pipes are arranged in a staggered manner;
the diameter difference of the two circles of the combustion head water-cooling tube bundles 134 is equal to the diameter of the combustion head water-cooling tube bundles 134, and the diameter difference of the two circles of the heat exchanger water-cooling tube bundles 23 is equal to the diameter of the heat exchanger water-cooling tube bundles 23; an ignition gun 136 is arranged at a certain distance outside the water-cooled tube bundle 134 of the combustion head of the outer ring and is used for igniting the mixed gas; an air inlet gap is formed between the combustion head water-cooling tube bundles 134 at the inner ring, so that the mixed air flow speed is ensured to be greater than the flame propagation speed under the rated minimum load to prevent tempering; the clearance of the outer ring combustion head water-cooling tube bundle is larger than that of the inner ring combustion head water-cooling tube bundle, so that the fire can be prevented from dropping under the rated maximum load, meanwhile, a high-temperature low-flow-rate flame stabilizing area is formed behind the outer ring combustion head water-cooling tube bundle 134, the flame can be stabilized to prevent the fire from dropping, and meanwhile, the outer ring combustion head water-cooling tube bundle 134 directly exchanges heat with the combustion flame, so that the temperature of a combustion area is reduced, particularly the temperature of a previous combustion reaction area is reduced, and the generation of NOx is inhibited.
Referring to fig. 1 and 8, in order to improve the thermal efficiency of the gas boiler, a U-shaped condensing heat exchanger needs to be additionally arranged below a bent pipe 232 of a bottom heat exchanger, in the prior art, flue gas flowing out radially at 360 degrees is collected to one side to enter a condenser, but airflow is compressed, expanded and changed in direction for multiple times, so that the condensing efficiency is not beneficial to improvement, and the resistance of the flue gas is increased.
Referring to fig. 1, the combustion head water-cooling tube bundle 134 and the heat exchanger water-cooling tube bundle 23 are made of stainless steel round light tubes or finned tubes and are arranged in a staggered manner; forced water circulation is carried out through a water pump, and cooling water can adopt the conditions of normal-temperature water supply, vacuum deoxidization, thermal deoxidization, steam cooling and the like; the bottom of the upper header 22 of the heat exchanger is provided with a boiler support 37 for supporting the boiler, the lower part of the boiler is provided with a central downward-inclined dew-bearing disc 34, condensed water flows downwards from the central area of the dew-bearing disc 34 to a condensed fluid outlet 35 and then is discharged, and two chimneys 36 are symmetrically arranged below the dew-bearing disc 34 for discharging flue gas. A flue, a dew bearing disc 34 and a chimney 36 are arranged below the water-cooled combustor 1 and the water-cooled heat exchanger 2, and the materials of parts such as the condensing heat exchanger, the flue, the dew bearing disc 34 and the chimney 36 are made of 304 or 316-grade or above austenitic corrosion-resistant stainless steel plates or pipes, and can also be replaced by plastics.
Referring to fig. 9, the gas boiler may be a steam or hot water boiler, and in the case of the steam boiler, a water level gauge should be disposed at one side of the outside of the U-shaped tube water-cooled heat exchanger 2, and the boiler may be a through-flow boiler, which requires relatively high water quality, and an external steam separation device may be provided to ensure the quality of steam; in the case of a natural circulation steam boiler, a reasonable steam space should be left inside the U-tube heat exchanger upper header 22. No matter which kind of steam boiler, low temperature boiler feed water gets into condensing heat exchanger earlier and makes low temperature flue gas condensation absorb the liquefaction latent heat of vapor in the flue gas, then gets into the first water inlet 132 of the combustion of water-cooled combustor 1 header, gets into 2 ~ 4 outlet pipes intercommunication water-cooled heat exchanger 2 inboard headers of header 133 lateral surface along circumference equipartition on the combustion, then flows to the outside header of U-shaped pipe water-cooled heat exchanger 2 along U-shaped pipe heat exchanger water-cooled tube bank 23 and draws forth steam supply thermodynamic system.
When the boiler is a hot water boiler, boiler return water firstly enters a condensation heat exchanger to enable low-temperature flue gas to condense and absorb liquefied latent heat of water vapor in the flue gas, then enters a combustion head water inlet 132 of a header on the inner side of a water-cooled combustor 1, then flows to 2-4 water outlet pipes uniformly distributed along the circumferential direction on the outer side of the header 133 on the outer side of the combustion head along a combustion head water-cooled tube bundle 134, then flows to a heat exchanger upper header 22 on the outer side along a U-shaped heat exchanger water-cooled tube bundle 23 to lead out a hot water supply thermodynamic system, when a steam and hot water connecting system is arranged, water flow is fully considered, and the trend of an upper tube bundle and a lower tube bundle is reasonably distributed by water flow.
Claims (10)
1. A full-premixing water-cooled gas boiler with a U-shaped pipe structure is characterized by comprising a water-cooled burner (1) and a water-cooled heat exchanger (2), wherein the water-cooled burner (1) and the water-cooled heat exchanger (2) are cylindrical, the water-cooled heat exchanger (2) is coaxially arranged on the outer side of the water-cooled burner (1), a premixer (12) and a water-cooled burner head (13) are arranged in the water-cooled burner (1), a water outlet of the water-cooled burner (1) is communicated with a water inlet of the water-cooled heat exchanger (2), and an outlet of the premixer (12) is communicated with a gas inlet of the water-cooled burner head (13; the water-cooled combustion head (13) comprises a combustion head water-cooled tube bundle and two combustion head upper header tanks (133), the two combustion head upper header tanks (133) are arranged in an inner-outer nested manner, and two ends of the combustion head water-cooled tube bundle are respectively communicated with the combustion head upper header tanks (133) on the inner side and the outer side; a water inlet of the combustion head upper header (133) is communicated with boiler feed water, a water outlet of the combustion head upper header (133) is communicated with a water inlet of the water-cooled heat exchanger (2), and a single water-cooled tube of the combustion head water-cooled tube bundle is U-shaped; a flow equalizing pore plate (131) is arranged on the inner side of the water-cooled combustion head, the flow equalizing pore plate (131) is cylindrical, the top of the flow equalizing pore plate is open, and the bottom of the flow equalizing pore plate is sealed; a gap is arranged between the inner side of the water-cooled combustion head and the flow equalizing pore plate (131), and the ignition gun (136) is arranged on the outer side of the water-cooled combustion head.
2. The fully premixed water-cooled gas boiler with the U-shaped pipe structure according to claim 1, wherein the combustion head water-cooled tube bundle (134) at least comprises two circles of combustion head straight pipes, the clearance of the outer circle of combustion head water-cooled tube bundle in the combustion head water-cooled tube bundle (134) is larger than that of the inner circle of combustion head water-cooled tube bundle, and the adjacent two circles of combustion head straight pipes are arranged in a staggered manner.
3. The fully premixed water-cooled gas boiler with U-shaped tube structure according to claim 1, wherein the gap between the inner side of the water-cooled burner head (13) and the flow equalizing pore plate is 5-10 mm.
4. The full premix water-cooled gas boiler according to claim 1, wherein the premixer (12) comprises an outer cylinder (121) and an inner cylinder (126) which are coaxially arranged, the outer cylinder (121) is coaxially arranged outside the inner cylinder (126), the bottom of the inner cylinder (126) is closed, and a plurality of inner cylinder spray holes are formed in the lower cylinder wall of the inner cylinder (126); a flow guide channel is arranged between the inner cylinder (126) and the outer cylinder (121), the flow area of the flow guide channel is gradually reduced from top to bottom, and the flow guide channel guides air entering an annular space between the outer cylinder (121) and the inner cylinder (126) to the central direction of the outer cylinder; a swirl vane (124) and a despin structure (125) are sequentially arranged below the inner cylinder (126); the despin structure (125) adopts a plurality of flow guide straight plates, and a plurality of airflow channels parallel to the axis of the outer cylinder (121) are formed between the straight plates and the outer cylinder (121).
5. The fully premixed water-cooled gas boiler with the U-shaped tube structure according to claim 4, wherein 20-30 swirl vanes (124) are uniformly arranged along the circumferential direction, and the number of the air flow channels is 4-10.
6. The fully premixed water-cooled gas boiler with the U-shaped tube structure according to claim 1, wherein the water-cooled heat exchanger comprises a heat exchanger upper header (22) and a heat exchanger water-cooled tube bundle (23), the heat exchanger upper header (22) comprises an inner heat exchanger upper header (22) and an outer heat exchanger upper header (22), and two ends of the heat exchanger water-cooled tube bundle (23) are respectively communicated with the inner heat exchanger upper header (22) and the outer heat exchanger upper header (22); the upper header (22) of the inner side and the upper header of the outer side of the heat exchanger are concentrically arranged, and a single water-cooling pipe of a water-cooling pipe bundle (23) of the heat exchanger is U-shaped; the upper header (22) of the heat exchanger on the inner side is provided with a water inlet of the heat exchanger, and the upper header (22) of the heat exchanger on the outer side is provided with a water outlet of the heat exchanger.
7. The fully premixed water-cooled gas boiler with the U-shaped tube structure according to claim 1, wherein the water-cooled heat exchanger comprises an upper heat exchanger header (22), a lower heat exchanger header (25) and a water-cooled heat exchanger tube bundle (23), one end of the water-cooled heat exchanger tube bundle (23) is connected with the upper heat exchanger header (22), and the other end is connected with the lower heat exchanger header (25); a single water cooling pipe in the heat exchanger water cooling pipe bundle (23) comprises three heat exchanger straight pipes (231), and two adjacent heat exchanger straight pipes (231) are connected through a bent pipe; the bottom of the lower heat exchanger header (25) is provided with a heat exchanger water inlet (21), and the top of the upper heat exchanger header (22) is provided with a heat exchanger water outlet (24).
8. The full-premix water-cooling gas boiler with the U-shaped pipe structure according to claim 1, wherein the water-cooling burner head (13) and the water-cooling heat exchanger (2) are both provided with a flue gas baffle and a heat insulation layer in the top and bottom horizontal directions, the heat insulation layer is arranged outside the flue gas baffle, and the water-cooling heat exchanger (2) is provided with a circle of flue gas baffle in the vertical direction in the bottom outside.
9. The fully premixed water-cooled gas boiler with the U-shaped tube structure according to claim 1, wherein a condensation heat exchanger (26) is arranged along the circumferential direction of the bottom of the boiler, a dew containing disc (34) is arranged below the condensation heat exchanger (26), a chimney (26) of the boiler is arranged below the dew containing disc (34), the heights of the dew containing disc (34) and the chimney (26) are gradually reduced from the periphery to the center, a hole is formed in the middle of the dew containing disc, and a condensate outlet is formed in the lowest position of the chimney (26).
10. The fully premixed water-cooled gas boiler with a U-shaped pipe structure according to claim 9, wherein the condensing pipe of the condensing heat exchanger is U-shaped, the condensing pipe of the condensing heat exchanger is a staggered light pipe, spiral finned pipe, H-shaped finned pipe or pin fin pipe along the flue gas scouring direction, and the condensing pipe is in a single-pipe-ring, double-pipe-ring, three-pipe-ring or four-pipe-ring structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011323855.XA CN112460568B (en) | 2020-11-23 | 2020-11-23 | Full premix water-cooling gas boiler of U-shaped tubular structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011323855.XA CN112460568B (en) | 2020-11-23 | 2020-11-23 | Full premix water-cooling gas boiler of U-shaped tubular structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112460568A true CN112460568A (en) | 2021-03-09 |
| CN112460568B CN112460568B (en) | 2022-02-22 |
Family
ID=74798614
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011323855.XA Active CN112460568B (en) | 2020-11-23 | 2020-11-23 | Full premix water-cooling gas boiler of U-shaped tubular structure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112460568B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115013973A (en) * | 2022-06-02 | 2022-09-06 | 西安交通大学 | Full premix water-cooling gas boiler |
| CN115235117A (en) * | 2022-07-21 | 2022-10-25 | 西安交通大学 | Pressure-bearing double-helix water-cooling coil horizontal premixing gas boiler |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201043873A (en) * | 2009-03-10 | 2010-12-16 | Babcock & Wilcox Power Gen Group Inc | Integrated split stream water coil air heater and economizer (IWE) |
| CN202709104U (en) * | 2012-07-11 | 2013-01-30 | 珠海市柏克莱能源科技有限公司 | Biomass gasification gas burner |
| CN105642024A (en) * | 2016-03-18 | 2016-06-08 | 上海交通大学 | Swirling de-swirling coupled efficient dedusting and demisting assembly |
| CN110388643A (en) * | 2019-07-26 | 2019-10-29 | 合肥工业大学 | The gas-air premixed device of hydrogen-enriched fuel gas combustion with reduced pollutants |
| CN111141028A (en) * | 2020-01-13 | 2020-05-12 | 西安交通大学 | Gas condensing boiler with high-adjusting-ratio water-cooling premixed combustion and high-strength heat exchange |
| CN211345893U (en) * | 2019-12-19 | 2020-08-25 | 西安交通大学 | Photo-thermal torch tower structure with complementation of combustible gas chemical energy and solar energy |
-
2020
- 2020-11-23 CN CN202011323855.XA patent/CN112460568B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW201043873A (en) * | 2009-03-10 | 2010-12-16 | Babcock & Wilcox Power Gen Group Inc | Integrated split stream water coil air heater and economizer (IWE) |
| CN202709104U (en) * | 2012-07-11 | 2013-01-30 | 珠海市柏克莱能源科技有限公司 | Biomass gasification gas burner |
| CN105642024A (en) * | 2016-03-18 | 2016-06-08 | 上海交通大学 | Swirling de-swirling coupled efficient dedusting and demisting assembly |
| CN110388643A (en) * | 2019-07-26 | 2019-10-29 | 合肥工业大学 | The gas-air premixed device of hydrogen-enriched fuel gas combustion with reduced pollutants |
| CN211345893U (en) * | 2019-12-19 | 2020-08-25 | 西安交通大学 | Photo-thermal torch tower structure with complementation of combustible gas chemical energy and solar energy |
| CN111141028A (en) * | 2020-01-13 | 2020-05-12 | 西安交通大学 | Gas condensing boiler with high-adjusting-ratio water-cooling premixed combustion and high-strength heat exchange |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115013973A (en) * | 2022-06-02 | 2022-09-06 | 西安交通大学 | Full premix water-cooling gas boiler |
| CN115013973B (en) * | 2022-06-02 | 2023-10-24 | 西安交通大学 | Full premix water-cooling gas boiler |
| CN115235117A (en) * | 2022-07-21 | 2022-10-25 | 西安交通大学 | Pressure-bearing double-helix water-cooling coil horizontal premixing gas boiler |
| CN115235117B (en) * | 2022-07-21 | 2023-10-31 | 西安交通大学 | Pressure-bearing double-spiral water-cooling coil horizontal premix gas boiler |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112460568B (en) | 2022-02-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112460567B (en) | Gas boiler with concentric single pipe ring water-cooling combustion and heat exchange | |
| CN110631260B (en) | Cylindrical gap type full-premixing water-cooling combustion head | |
| CN112460568B (en) | Full premix water-cooling gas boiler of U-shaped tubular structure | |
| CN101725969A (en) | Low-NOx pulverized coal burner | |
| CN110848681A (en) | Large-load ultralow-nitrogen combustor suitable for low-heat-value and low-pressure fuel gas | |
| CN110864289A (en) | Multistage preheating dual-mode low-NOx self-preheating burner | |
| CN115013973B (en) | Full premix water-cooling gas boiler | |
| CN115493296B (en) | Short-flow ultra-compact gas boiler capable of coupling premixed combustion and local backfire | |
| CN117028987A (en) | Vertical water pipe built-in premixing membrane type wall cooling burner and gas boiler | |
| CN210832553U (en) | Preheating type combustion coil condensation heat exchanger | |
| CN117346141A (en) | Gas burner | |
| CN102434881B (en) | Multi-section self-preheating burner | |
| CN215723204U (en) | Diffusion type low NOx self-preheating radiant tube burner with flue gas backflow | |
| CN113446732B (en) | Air mixing device at tail part of hot blast stove | |
| CN211011926U (en) | Cylindrical gap type full-premixing water-cooling combustion head structure | |
| CN101726111A (en) | Non-premixing inverted condensing gas water heater | |
| CN211551581U (en) | Large-load ultralow-nitrogen combustor suitable for low-heat-value and low-pressure fuel gas | |
| CN208952091U (en) | Premix the super low NO of open type | |
| CN111878794A (en) | Finned tube type multi-return low-nitrogen condensation fuel gas evaporator | |
| CN220870865U (en) | Multistage tubular low NOx self-preheating burner | |
| CN108730976A (en) | Premix the super low NO of open type | |
| CN216897838U (en) | Full-premixing combustion wave type fire tube gas water heater | |
| CN201193825Y (en) | Oil-gas combined type low NOx combustor | |
| CN217131520U (en) | Full premix jet-type hot water boiler | |
| CN220169447U (en) | Gas burner |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |