| 摘要 |
PURPOSE:To make it possible to prevent an unnecessary defrosting operation from being performed due to an external disturbance and to perform a necessary defrosting operation accurately by a method wherein the defrosting operation is performed on the base of an absolute primary differential value of the difference between the temperature of air at the inlet port and the temperature of air at the outlet port of a user side heat exchanger with respect to time. CONSTITUTION:In a defrosting method for a heat pump type air conditioner using air as a heat source in which a defrosting operation is started when the difference DELTAT between the temperature of air at the inlet port and that at the outlet port of the user side heat exchanger drops down to a rate determined with respect to a stored maximum value DELTATmax, the defrosting operation is performed with reference to the temperature difference DELTAT per se when the absolute primary differential value of the temperature difference DELTAT with respect to time is smaller than a predetermined value. On the contrary, when the absolute primary differential value is larger than the predetermined value, the temperature difference DELTAT is monitored at a point of time of (tau=tau3+a) reached after a lapse of a predetermined time (a) from an hour tau3, coefficient of correction (k) of DELTAT is calculated in accordance with the shown equation so as to compensate for the external disturbance and DELTAT is multiplied by the coefficent of correction (k) to thereby enable the defrosting operation to be performed accurately. |
