Method for defrosting an external heat exchanger, which is operated as an air heat pump, of a cooling system for a motor vehicle, cooling system, and motor vehicle having such a cooling system

• Main Authors: Rottenkolber, Helmut, Rebinger, Christian, Schroeder, Dirk
• Format: Patent
• Language: English
• Published: 21.11.2023
• Subjects: ARRANGEMENTS OR ADAPTATIONS OF HEATING, COOLING, VENTILATING,OR OTHER AIR-TREATING DEVICES SPECIALLY FOR PASSENGER OR GOODSSPACES OF VEHICLES; PERFORMING OPERATIONS; TRANSPORTING; VEHICLES IN GENERAL

A method for defrosting an external heat exchanger, operated as an air heat pump evaporator, of a cooling system for a motor vehicle. The cooling system includes a refrigerant compressor connected to a primary and secondary section; an external heat exchanger; an evaporator; a heating register; a primary section valve which is closed in the air heat pump operation; and a secondary section valve which is open in the air heat pump operation. The method includes closing of the secondary section valve; opening of the primary section valve, so that refrigerant flows directly from the refrigerant compressor to the external heat exchanger; and setting an inlet-side pressure level of the refrigerant on the external heat exchanger to a target pressure which corresponds to a condensation temperature (Tkond) of the refrigerant in the range: 2° C.≤Tkond≤20° C., in particular 4° C.≤Tkond≤10° C.