This product uses diesel heavy oil, natural gas, city gas, coke oven gas, low-calorific value generator gas, liquefied gas, and industrial combustible waste liquid and waste gas as fuel. It has a horizontal three-return structure. The balance between the flame volume of the burner and the heat exchange surface area makes the exhaust pipe The outlet flue gas reaches a suitable temperature, and the extra-thick insulation layer makes the boiler heat dissipation reach a minimum. All types of boilers are assembled boilers, and only the system equipment and pipelines need to be connected when the boiler is installed. The integrated boiler design makes installation easier and faster. No special foundation is required for all boilers. Intelligent control makes the operation of the boiler particularly convenient and simple. The controller is an analog screen display, centralized control by the central processor, with automatic ignition and furnace shutdown program control, automatic combustion control, automatic switching and control of the circulating pump, automatic failure processing and alarm functions.