A fully premixed water-cooled gas boiler with u-shaped tube structure

Abstract

The invention discloses a fully premixed water-cooled gas boiler with a U-shaped tube structure, which includes a coaxially arranged water-cooled burner and a water-cooled heat exchanger, a premixer and a water-cooled combustion head are arranged in the water-cooled burner, and a water outlet of the water-cooled burner It is connected to the water inlet of the water-cooled heat exchanger, and the premixer is connected to the air inlet of the water-cooled combustion head; the water-cooled combustion head includes the water-cooled tube bundle of the combustion head and the upper header of the combustion head. The two ends are respectively connected to the upper header of the combustion head on the inner side and the outer side; the water inlet of the upper header of the combustion head is connected to the boiler feed water, and the single water-cooled tube of the water-cooled tube bundle adopts a U shape; On the outside of the water-cooled combustion head; the flue gas flows out of the water-cooled combustion head and flows evenly to each water-cooled tube bundle in the water-cooled heat exchanger, and then flows down through the gap between the outer ring water-cooled tube bundle and the furnace wall to the dew receiving plate and then is discharged through the chimney. The heat capacity is greatly improved, which contributes to the safe and stable operation of the boiler.

Description

technical field [0001] The invention belongs to the field of safe and stable low-nitrogen combustion of natural gas, burners and boiler design, and in particular relates to a fully premixed water-cooled gas boiler with a U-shaped tube structure. Background technique [0002] Burners are divided into diffusion burners, partial premix burners and full premix burners according to whether they are mixed before combustion and the degree of mixing. Diffusion burners are simple in structure, safe and reliable in operation, and have no flashback risk, but they have longer flames and larger combustion space; some premixed burners are mainly used in traditional small wall-mounted gas boilers, and the structure is bulky when the heat load is large; The fully premixed gas combustion method has high combustion intensity, short flame, small volume of combustion equipment, uniform combustion, and no local high temperature zone. It has significant advantages in large gas boilers, but it may...

AI Technical Summary

Problems solved by technology

Water-cooled burners have developed rapidly in recent years, but they are mostly used in small wall-hung boilers. Because of their poor adaptability to boilers, the transformation workload is large

[0003] The traditional boiler adopts the upper and lower square header structure, which is welded by 4 steel plates or the upper and lower half heads and the short cylinder. Both the straight tube bundle and the upper and lower headers need to be welded. Both ends of the straight tube need to be necked, which increases the process cost. , too many solder joints; in traditional boilers, the flue gas after burner combustion flows to one side of the water-cooled heat exchanger tube bundle, and then flows out around the gap between the outer ring tube bundle and the furnace wall, and the temperature distribution of the water-cooled tube bundle at different positions is extremely uneven , easily lead to accidents such as pipe bursts

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