Fuel delivery system

A fuel delivery system according to the present invention comprises: a fuel tank for accommodating a fluid used as a fuel; the heat exchange unit performs heat exchange on the fluid; and a temperature adjustment means for selectively adjusting the temperature of a primary discharge fluid, which is a fluid whose temperature is changed by the heat exchange means, the heat exchange means comprising: a housing in which a predetermined accommodation space is formed, a heat medium inlet and a heat medium outlet are formed, and the heat medium inlet and the heat medium outlet are formed; the heat medium inlet allows a heat medium for adjusting the temperature of a fluid to be subjected to heat exchange to flow in, and the heat medium outlet allows the heat medium to flow out; a first chamber coupled to the housing and into and out of which a heat-exchanged first fluid flows; a second chamber coupled to the housing, forming an internal space separated from the first chamber, and allowing a second fluid for heat excha