| 摘要 |
A gas water heater includes a water tank, a combustion chamber, a burner, a heat exchanger tube at least partially within the water tank, and a fan. The burner receives fuel gas and primary air from a first air-supply channel to create a primary air-fuel mixture for combustion in the combustion chamber with secondary air. The primary air-fuel mixture has a gas concentration above the upper explosive limit of the fuel gas. Secondary air is supplied through a second air-supply channel to the combustion chamber. The secondary air creates a low excess air ratio (e.g., below 1.5) for combustion in the combustion chamber. A totally sealed channel is defined from the air inlet of the fan to the heat exchanger tube. |
