Fuel cooling system for motorvehicles

A fuel cooling system for a motor vehicle which comprises a heat exchanger in line with a fuel return pipe for returning fuel from an engine to a fuel tank and in line with a refrigerant pipe through which passes a refrigerant:

• said heat exchanger including,
• an inner tube having a first end in communication with a first section of the refrigerant pipe and a second end in communication with a second section of the refrigerant pipe so as to define a longitudinal inner flow passage between said first and second inner tube ends;
• an outer tube encompassing said inner tube so as to form an enclosed annular space which defines a longitudinal outer flow passage;
• connecting means for connecting said enclosed annular space with the fuel return pipe, said connecting means including a first connecting member opening into said enclosed annular space and connected to a first section of the fuel return pipe and a second connecting member opening into said enclosed annular space and connected to a second section of the fuel return pipe, said second connecting member being positioned downstream in fuel flow direction to said first connecting member;
• first heat transfer fin means secured in said inner flow passage, said first heat transfer fin means extending in said inner flow passage longitudinally thereof and being wave-shaped in a cross section taken perpendicuarly to a longitudinal axis of the inner flow passage so as to have a plurality of wave portions, said wave portions being arranged circumferentially within the inner flow passage so as to encircle a longitudinal axis of said inner tube;
• and
• second heat transfer fin means secured in said outer flow passage, said second heat transfer fin means comprising helical heat transfer fins disposed in said outer flow passage and extending radially outward from the inner tube and longitudinally along the outer flow passage.