STORAGE GAS WATER HEATER

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 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 to the combustion chamber through a secondary air conduit that is separate from the burner. The heat exchanger tube receives the products of combustion, transfers heat from the products of combustion to water in the tank, and exhausts of the products of combustion. Only air flows through the fan; no fuel-air mixture flows through the fan. The water heater utilizes partial premix combustion with low excess air ratio and low contaminant emission. The water heater utilizes a high power burner such that the water heater can supply hot water continuously during low flow rate draws and hot water stored in the tank supplements the hot water supply of the water heater during higher flow rate draws.