| 摘要 |
PURPOSE:To constantly secure the heating capacity of not lower than the minimum heating capacity, by a method wherein the capacity of a circulating pump is controlled to maintain hot water temperature at a set point when the heating capacity is not lower than a predetermined value, and the capacity of the pump is controlled to maintain the heating capacity to be constant when the heating capacity is lower than the predetermined value. CONSTITUTION:In a temperature-basis controlling circuit 21, a rotating speed controlling circuit 23 determines the rotating speed of a pump 9 so that the output hot water temperature TH of a heat-pump heating unit 1 becomes equal to a temperature set point signal THS, and the amount Q of water circulated is determined. In a capacity-basis controlling circuit 22, a heating capacity calculating circuit 24 calculates the heating capacity KH from the output hot water temperature TH of the heating unit 1, water temperature TW and a detection signal (9) fed from a detector 18 for the amount Q of water circulated, and the rotating speed N of the pump 9 is controlled by the circuit 23 so that KH KS (wherein KS is a capacity set point signal). When the enthalpy ha of a heat source is low and KH<KS, a control logic circuit 20 converts the control logic to give priority to the capacity-basis controlling circuit 22. |
