DZL series of pot shell type hot water boiler is set according to the characteristics of the hot water boiler, the structure of the existing boiler at home and abroad on the basis of the application of advanced technology such as heat transfer enhancement threaded pipe, the design and development of new type hot water boiler. The boiler has the advantages of novel structure, reliable operation, high thermal efficiency, low resistance furnace the internal operation and forced circulation, the original dust concentration is low, easy maintenance, etc.