Control of hot water central heating system - is operated by temp. difference between flow and return

摘要

A central heating system employing a hot water flow has a temp. controller which automatically regulates temp. of the inlet flow as a function of return flow temp. Ambient and demanded temps. are included. A principal source of energy comprising solar panels (46) heats water in accumulator reservoir (31). Heat from a conventional burner (52) is transmitted via thermal exchange surfaces to the water in the reservoir (31). A control unit (42) with temp. sensors (38, 40) in the flow and return pipes controls the burner (52) to maintain temp. within upper and lower limits. A second reservoir (54) for domestic hot water (30) is heated by solar panels (46) and by a secondary energy source (74) which is controlled by a control unit (70) with temperature sensors (66, 68) in the flow and return circuits.