The invention discloses a
hearth and
combustor cooling type surface cold
flame premixing gas boiler. The boiler comprises a
hearth, a
water cooling combustor is installed at the position of an inlet of the
hearth, an outlet of the hearth is connected to a reversal chamber, U-shaped
water cooling components are evenly arranged in the hearth in the circumferential direction, inlets of the U-shaped
water cooling components are evenly connected to an annular pipeline in the circumferential direction, and water outlets of the U-shaped water-cooling components and a water outlet of the water coolingcombustor are connected to a
boiler water tank. According to the hearth and
combustor cooling type surface cold
flame premixing gas boiler, by the adoption of the water cooling combustor, uniform gascombustion can be achieved, the
flame root
combustion temperature is reduced while a local high-temperature area is not generated, generation of thermal
NOx at the flame root is reduced, and meanwhile, a hearth cooling
system is adopted, a U-shaped pipeline cooling structure is arranged, the compact structure and manufacturing economy of the boiler are achieved while the uniform low-temperature
atmosphere in the boiler is guaranteed, and generation of the
NOx during gas fuel
combustion is further remarkably reduced.