RETURN FUEL COOLING SYSTEM FOR LPI VEHICLE, AND ITS CONTROLLING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a return fuel cooling system for LPI vehicle and its controlling method in which LPG fuel returned from an engine is efficiently cooled to prevent a pressure of a cylinder from being increased.SOLUTION: An engine 3 and a cylinder 5 are connected to each other through a fuel supply line 7 and a fuel return line 9. This system comprises: a heat exchanger 20 installed at the fuel return line 9 for heat exchanging refrigerant of an air conditioner unit 10 and LPG fuel to each other inder to cool the LPG fuel of high temperature returned from the engine 3 to the cylinder 5; a bypass line 30 for bypassing the LPG fuel around the heat exchanger 20 to supply it to the cylinder 5; and a valve 40 for selectively opening or closing the fuel return line 9 in response to whether or not the air conditioner unit 10 is operated and a temperature of the cylinder 5, for flowing the LPG fuel into the heat exchanger 20 or bypassing the LPG fuel to the bypass line 30.