Abstract: A method is provided for reducing vapor generation in a temperature controlled fuel tank in a motor vehicle. The method cooperates with an apparatus having hot and cold fluid sources (20, 22), a heat exchanger (18) having hot and cold valves (26, 24) and an air blower (28) to force temperature conditioned discharge air flow onto a fuel tank (12). The method involves comparing actual and desired fuel temperature signals and producing a first error signal from the comparison. The method then produces a gain signal in response to an operating mode signal and the error signal. A first control signal is then generated in response to the first error signal representing the difference between a desired fuel temperature and the actual fuel temperature. Finally, the heat exchanger is actuated by supplying the first control signal to the cold and hot valves.

Abstract: An apparatus for controlling the temperature of fuel in a motor vehicle fuel tank is described. The apparatus includes a cold valve (24) fluidly interposed between a cold fluid source (20) and a cooling portion (50) of a heat exchanger (18) and a hot valve (26) fluidly interposed between a hot fluid source (22) and a heating portion (48) of the heat exchanger (18). An air blower (28) forces air through an air duct (30) fluidly interposed between the heat exchanger (18) and an air outlet (32) to be discharged onto the vehicle fuel tank (12). A fuel temperature sensor (40) measures the temperature of the fuel in the fuel tank and generates a first input signal which is communicated to a controller (34) which then generates a control signal. The controller communicates the control signal to the cold and hot valves, whereby the cold and hot valves respond so as to maintain the difference between the first input signal and a predetermined fuel temperature profile within a predetermined range.