| 摘要 |
PROBLEM TO BE SOLVED: To provide a combustion device of a household water heater or the like which produces little CO, HC and NOx, while enhancing thermal efficiency, and of which the heat radiator is cooled, so that the durability be improved. SOLUTION: The combustion device 1 comprises a cooling pipe 15 through which external air 17 is supplied, a heated-air pipe 16 which returns the heated air from an outlet of the cooling pipe 15 to a burner part 2, and a flow control valve 20, a temperature sensor 21, a control mechanism 22, etc., for controlling the temperature of cooling air 13 to be in a prescribed range. These elements are provided inside the heat radiator 3 or in the vicinity thereof. |
