초록 ▼

A system for controlling a water heating system senses the temperature of new (unheated) water and uses any drop in that temperature as an early, quantitative measure of the demand for hot water within the system. The heater itself is turned “on”and “off”with respect to a control set point temperatu

A system for controlling a water heating system senses the temperature of new (unheated) water and uses any drop in that temperature as an early, quantitative measure of the demand for hot water within the system. The heater itself is turned “on”and “off”with respect to a control set point temperature (TC) which increases with decreasing inlet water temperature. Thus, the control set point is increased above a baseline by an amount related to the amount of unheated water drawn into the heater to replenish the heated water being used. In a preferred embodiment, a calculated demand value proportional to the drop in inlet water temperature (TI) is summed over time to reflect the time during which a given demand condition continues. When the heater is ultimately turned “off”, signifying that the hot water supply temperature (TS) is substantially higher than the control temperature (TC), the control temperature is reset to its baseline value.

대표청구항 ▼

A controller for a water heating system having a heater, an outlet conduit for supplying heated water to a plurality of users, and an inlet conduit for introducing unheated water through an inlet orifice to replenish heated water supplied to said users, the controller comprising: an outlet sensor fo

A controller for a water heating system having a heater, an outlet conduit for supplying heated water to a plurality of users, and an inlet conduit for introducing unheated water through an inlet orifice to replenish heated water supplied to said users, the controller comprising: an outlet sensor for measuring an outlet temperature of said heated water and generating an outlet temperature signal representative thereof; an inlet sensor for measuring an inlet temperature of said unheated water at a location adjacent the inlet orifice such that said inlet temperature drops when unheated water is introduced; logic responsive to said inlet temperature signal to derive a control temperature value which varies continuously with the amount by which said inlet temperature drops; and control circuitry responsive to said outlet temperature signal for controlling the heater to maintain a preselected relationship between said outlet temperature and said control temperature value.