Boiler flue heat recovery system - has two heat exchangers in series with separate water circulating circuits

摘要

A heat recovery system for a boiler has two heat exchangers between the boiler gas outlet (2) and the chimney. The first heat exchanger (3) has a feed water return circuit (10, 11) and the second (4) acts as a water heater, both exchangers being positioned in a common housing (15). The first circuit receives direct heat, and the second receives the heat of condensation. The first circuit has its own pump (11) and receiver (9) with a return line (10) so that the flow so in the opposite direction to the flow in the other circuit. The latter circuit heats water for general use.