| 摘要 |
In a heating system for a building 1 and comprising a heating boiler (2), a feed water line (3) with a mixing valve (4) and a circulating pump (5) or circulating pump group, room heaters H1-Hn, a return water line (6), a by-pass line (7), a valve control motor (8) and associated amplifier (9), an external temperature sensor (10) with an associated temperature-voltage transducer (11) and heating curve setting means (12) to provide a reference signal SW to the amplifier (9), and means for providing a control or feedback signal IW which is dependent on mean water temperature to the other side of the amplifier (9), the speed or delivery of the pump(s) is made to vary (continuously or in steps) with at least one of the parameters: time - e.g. day/night; pump delivery head; external temperature TA; feed water temperature THV or system temperature difference (THV - THR) or mean water temperature (THV +THR)/2. As shown the pump (5) has two speeds selected by switching amplifiers (16,17) and respective relays (18,19) in dependence on the external temperature TA. The control signal IW is derived as the mean of the feed and return water temperatures THV, THR by sensors (13,14). The system can thus function efficiently both at normal and maximum heat demands and with a single setting means (12) responsive to external temperature TA. <IMAGE> |
