Refrigeration Circuit, and Heat Management System and Motor Vehicle Having a Refrigeration Circuit of This Type

A refrigeration circuit for a motor vehicle comprising:

• a refrigerant compressor;
• a condenser configured to exchange heat with a cooling circuit;
• a chiller configured to exchange heat with the cooling circuit;
• an evaporator configured to control a temperature of air in an air-conditioning device, wherein the evaporator is arranged in parallel with the chiller, wherein the refrigerant compressor, the condenser and the parallel circuit comprising the chiller and the evaporator are connected in series in a main circuit;
• a return line that branches off from the main circuit on a high-pressure side of the refrigerant compressor and leads into the main circuit on a low-pressure side of the refrigerant compressor;
• and
• a valve circuit configured to block and release flow through the return line.

A method for controlling a refrigeration circuit, the refrigeration circuit comprising:

• a refrigerant compressor;
• a condenser configured to exchange heat with a cooling circuit;
• a chiller configured to exchange heat with the cooling circuit;
• an evaporator configured to control a temperature of air in an air-conditioning device, wherein the evaporator is arranged in parallel with the chiller, wherein the refrigerant compressor, the condenser and the parallel circuit comprising the chiller and the evaporator are connected in series in a main circuit;
• a return line that branches off from the main circuit on a high-pressure side of the refrigerant compressor and leads into the main circuit on a low-pressure side of the refrigerant compressor;
• and
• a valve circuit configured to block and release flow through the return line;
• the method comprising:
• operating the refrigeration circuit in an operating state in which the valve circuit blocks flow through the main circuit and releases flow through the return line, thus preventing heat dissipation from the refrigeration circuit via a heating condenser and the condenser.

A method for controlling a refrigeration circuit, the refrigeration circuit comprising:

• a refrigerant compressor;
• a condenser configured to exchange heat with a cooling circuit;
• a chiller configured to exchange heat with the cooling circuit;
• an evaporator configured to control a temperature of air in an air-conditioning device, wherein the evaporator is arranged in parallel with the chiller, wherein the refrigerant compressor, the condenser and the parallel circuit comprising the chiller and the evaporator are connected in series in a main circuit;
• a return line that branches off from the main circuit on a high-pressure side of the refrigerant compressor and leads into the main circuit on a low-pressure side of the refrigerant compressor;
• and
• a valve circuit configured to block and release flow through the return line;
• the method comprising:
• operating the refrigeration circuit in an operating state in which the valve circuit releases flow through the main circuit and releases flow through the return line.