METHOD OF OPERATING A HEAT PUMP DRYER AND HEAT PUMP DRYER

摘要

Heat pump dryer (1) comprising a process air circuit and a heat pump unit (5) having a primary refrigerant evaporator (6) for cooling process air (4), a primary refrigerant condenser (7) for heating process air (4), an auxiliary refrigerant evaporator (16) arranged outside the process air circuit and connected between the primary refrigerant evaporator (6) and a compressor (8) of the heat pump unit (5), and at least one auxiliary fan (18) adapted to impinge an air stream at the auxiliary refrigerant evaporator (16). At least one waste heat generating component (25) of the heat pump dryer (1), the auxiliary refrigerant evaporator (16) and the auxiliary fan (18) are mutually arranged so that the auxiliary fan (18) is adapted to impinge ambient air heated up by heat released from said waste heat generating component (25) at the auxiliary evaporator (16), and/or at least a temperature sensor (23) is arranged outside the process air circuit and provided for detecting the temperature of the ambient air around the location where the auxiliary refrigerant evaporator (16) is arranged.