COIL TUBE HEAT EXCHANGER FOR A TANKLESS HOT WATER SYSTEM

摘要

A novel water heat exchanger with a helix coil incorporated into an elongated variable diameter cylindrical housing. A buffer tank is incorporated within the lumen of the helix coil. The heat exchanger utilizes a radial direct-firing burner and a blower-driven hot flue gas to heat water. At least a rope seal is disposed between adjacent coil loops of a portion of the helix coil for enhancing heat transfer to the helix coil. In one embodiment, solar and electric heating systems are combined with the helix coil heat exchanger to provide supplemental heating. In another embodiment, the heat exchanger further comprises a Stirling engine comprised of a free piston having hot and cold ends, wherein the hot end receives heat from the burner and the cold end is cooled by the incoming cold water line to form an electric power generator.