Waste heat recovery system for domestic boiler - uses heat exchanger coil inside chimney adding heat to return line from radiators

摘要

The waste heat recovery system uses a heat exchanger coil (6) which matches the shape of the chimney and which is installed inside immediately above the junction with the flue gas duct. The coil can be made up of sections added one after the other, installed by insertion into the top of the chimney. The coil is connected in the return line from the radiators so that the returning water is preheated before entering the boiler again. Adaptors can be used to divide the incoming flow to the coil into more than one flow. A flap is fitted to the top of the coil, so that the chimney can be cut off when the burner is not in operation. The connections to the coil are made horizontally through the side of the chimney near the boiler. Due to the shape of the coil, the cross-sectional opening of the chimney is reduced by a minimum amount.