Abstract: A cooling system includes: connected in a loop by fluid lines and in succession, a compressor, a condenser, an expansion valve, and an evaporator; and an internal heat exchanger having a first conduit in heat exchanging contact with a second conduit, the first conduit being part of the fluid line between the condenser and the expansion valve and the second conduit being part of the fluid line between the evaporator and the compressor. A bypass fluid line is arranged between two ends of the first conduit of the internal heat exchanger or extends between one of the two ends of the first conduit and a position along a length of the first conduit.

Abstract: A heat exchanger comprising an outer conduit and an inner conduit, arranged inside of and along the longitudinal axis of the outer conduit, the inner conduit and the outer conduit being arranged to form a fluid flow channel between the inner surface of the outer conduit and the outer surface of the inner conduit, the fluid flow channel having a cross sectional form, in a plane substantially perpendicular to the longitudinal axis of the outer conduit, that is elongate being substantially greater in the circumferential direction of the outer conduit than in the radial direction of the outer conduit.