650 DEG C ultra-supercritical horizontal supercharged boiler and circulating system

The invention discloses a 650 DEG C ultra-supercritical horizontal supercharged boiler and a circulating system. When a boiler in the prior art operates, the problems of pulverized coal ignition, poor stable combustion characteristic, low boiler thermal efficiency, weak steam temperature reaching capacity and the like exist in a hearth. The system comprises a 650 DEG C ultra-supercritical horizontal supercharged boiler (1), the 650 DEG C ultra-supercritical horizontal supercharged boiler is of a horizontal arrangement structure, a pressure-bearing boiler shell sealing structure is adopted on the periphery of a boiler body, a convection heating surface of a horizontal flue is vertically arranged in the flowing direction of smoke, combustors are arranged on two side walls, and the two side walls of the boiler body are communicated with the horizontal flue. Air in the burner area is respectively connected with a gas compressor (2) and a starting fan (3) through pipelines, the gas compressor is connected with a t