The invention relates to a device and a method for
icing prevention regulation for a
heat pump evaporator (3) in
air conditioning systems of vehicles, composed of a subsection (1) of a
refrigerant circuit which can be operated both as a
heat pump and also as an air-conditioning
system. The device comprises the
heat pump evaporator (3), an electrical or mechanical
refrigerant compressor (4), a cooler fan (9) which is assigned to the heat pump
evaporator (3) and which draws
ambient air (11) upstream of and through the heat pump evaporator (3) at an adjustable flow speed and which thus permits a permanent flow of
ambient air (11) over the heat pump evaporator surface, a first temperature sensor (6) in or on the
refrigerant line (5, 5a) upstream of the heat pump evaporator (3) with respect to the heat pump operating direction, and a control and regulating unit (8). The control and regulating unit (8) is connected via
signal lines (10, 10a, 10b, 10c, 10e) at least to the first temperature sensor (6), to further sensors, in particular for detecting the
ambient air temperature (Tu) and the vehicle speed (VF), to the expansion valve (2), to the cooler fan (9) and to the refrigerant compressor (4) for the direct or indirect regulation of the flow cross section of the expansion valve (2) and the rotational speed of the electric refrigerant compressor (4) or of the regulating valve of the mechanical refrigerant compressor (4) and for the actuation of the cooler fan (9) of the vehicle during heat pump operation.