This product is based on diesel heavy oil natural gas city gas coke oven gas low calorific value producer gas and liquefied gas and industrial combustible waste liquid and waste gas as fuel, horizontal three-return structure, burner flame volume and heat exchange surface area balance to make smoke exhaust pipe The outlet flue gas reaches the optimum temperature, and the extra thick insulation layer minimizes the heat dissipation of the boiler. All types of boilers are assembled boilers, and only the system equipment and pipelines need to be connected to the boiler installation. The design of the integrated boiler makes installation easier and faster. All boilers do not require special foundations. Intelligent control makes boiler operation particularly convenient and simple. The controller is analog screen display, centralized control by central processor, automatic ignition and shutdown program control, automatic combustion control, automatic switching and control of circulating pump, automatic fault handling and alarm.