SZS series low nitrogen hot water boiler is water pipe structure, vertical "D" shape arrangement, micro-positive pressure combustion; Low nitrogen emissions are achieved by using two technologies in the world of low nitrogen combustion, namely segmented combustion and FGR gas recirculation. The use of integrated and modular design, conducive to the production of large-capacity boiler modules, burner configuration, automatic control, to ensure quality, quality and performance, safety.