Vapour-compression circuit

A vapour-compression circuit for circulating a working fluid, the vapour-compression circuit comprising a compressor, a first heat exchanger, an expansion device, a second heat exchanger, a discharge line, a bypass line and a controller, wherein

• the discharge line extends from an outlet of the compressor to an inlet of the first heat exchanger;
• the vapour-compression circuit is configured to operate in a heating mode in which the first heat exchanger operates as a condenser and the second heat exchanger operates as an evaporator;
• and
• the vapour-compression circuit is configured to operate in a defrost mode in which the working fluid is directed from the compressor to the second heat exchanger via the bypass line and the expansion device, the bypass line extending from the discharge line to bypass the first heat exchanger.

A vehicle comprising vapour-compression circuit for circulating a working fluid, the vapour-compression circuit comprising a compressor, a first heat exchanger, an expansion device, a second heat exchanger, a discharge line, a bypass line and a controller, wherein

• the discharge line extends from an outlet of the compressor to an inlet of the first heat exchanger;
• the vapour-compression circuit is configured to operate in a heating mode in which the first heat exchanger operates as a condenser and the second heat exchanger operates as an evaporator;
• and
• the vapour-compression circuit is configured to operate in a defrost mode in which the working fluid is directed from the compressor to the second heat exchanger via the bypass line and the expansion device, the bypass line extending from the discharge line to bypass the first heat exchanger;
• wherein the controller is configured to control the expansion device based on a superheat of working fluid discharged from the second heat exchanger in the defrost mode;
• and
• wherein the vehicle comprises at least one of:
• a prime mover configured such that the compressor is mechanically coupled to the prime mover;
• and
• an electric motor configured such that the compressor is mechanically coupled to the electric motor.