The boiler adopts the combined structure of the shell-type pyrotechnic tube heating surface and the water tube heating surface, giving full play to the technical advantages of the two heating surfaces. The drum adopts a quasi-elastic combination structure of arched tube sheet and threaded smoke tube, Chain grate which not only makes the boiler structure compact, but also has good low-cycle fatigue resistance. The water wall on the boiler side and the convective heating surface of the water pipe adopt a parallel structure, Chain grate and are connected with the upper and lower headers, which not only have high heat transfer efficiency, but also serve as the supporting structure of the boiler body to ensure that the boiler can freely expand upward under working conditions, Chain grate and the boiler is safe to operate reliable;
All boilers use the heating surface of the convection tube bundle as the flue gas flow behind the furnace to ensure that the flue gas temperature of the front tube plate flue box is lower than 650℃, Chain grate eliminating the possibility of local supercooling and fouling at the end of the flue tube. It also eliminates the hidden danger of tube plate cracks, Chain grate and fundamentally solves the crack accidents that sometimes occur in the front tube plate hole bridge area of the raw water fire tube shell hot water boiler with wing-shaped flue structure;
The working fluid of the boiler adopts compound circulation technology. The front arch tube and the heating surface of the front wall of the boiler, and the heating surface of the rear arch and the back wall adopt the natural circulation method of the working fluid. The side water wall tube and the side convection tube bundle are forced to circulate during normal operation to ensure the side water wall tube. The water speed in the convection tube bundle is not only higher than the safe water speed of the heat load it receives, Chain grate but also ensures that the sediment carried by the backwater cannot be deposited in the lower header, Chain grate completely eliminating the possibility of tube bursting in the side water wall tube