Cooling system of a vehicle, comprising a coolant circuit which can be operated as a cooling circuit for an AC operation and as a heat pump circuit for a heating operation

A cooling system of a vehicle having a primary coolant circuit which is operable as a cooling circuit for an AC operation and as a heat pump circuit for a heating operation, the cooling system comprising:

• an evaporator;
• a coolant compressor;
• a heat exchanger as a coolant condenser or a gas cooler for the cooling circuit or as a heat pump evaporator for the heat pump circuit;
• a first expansion valve corresponding to the evaporator;
• a second expansion valve corresponding to the heat exchanger;
• and
• an internal heat exchanger comprising a high-pressure section and a low-pressure section, wherein the coolant compressor is fluidically arranged immediately downstream of the low-pressure section and the high-pressure section is part of a coolant circuit section which connects the second expansion valve to the heat exchanger,
• wherein the primary coolant circuit comprises a coolant path, the coolant path beginning at an outlet of the coolant compressor, ending at an inlet of the coolant compressor, and following a flow direction of the primary coolant circuit,
• wherein, along the coolant path of the primary coolant circuit:
• a controllable valve is fluidically arranged between the high-pressure section of the internal heat exchanger and a junction at which both the second expansion valve and a series connection of the evaporator and the first expansion valve meet;
• and
• the high-pressure section is fluidically arranged between the controllable valve and the heat exchanger, and
• wherein, during the heating operation, the cooling system is configured to actively flow the high-pressure section of the internal heat exchanger and to control the second expansion valve and/or the controllable valve to reduce a coolant pressure in the high-pressure section to that of the low-pressure section, thereby disabling the internal heat exchanger during the heating operation.