Abstract: A method for operating a fuel system for an internal combustion engine operated with fuel gas. The fuel system has at least one electrically actuated shutoff valve (4) and at least one electrically operated heating device (14, 16). The operating method includes: generating a signal to turn on the heating device (14, 16) when the internal combustion engine is turned on; determining a heating demand (?reference) of the fuel system when the heating device (14, 16) is turned on; and depending on the heating demand (?reference) of the fuel system, determining a delay time between the time the heating device (14, 16) is turned on and the time the shutoff valve (4) is opened. The heating demand (?reference) can be a function of a temperature (Tengine coolant) of the engine and/or a temperature (Thydraulic fluid) independent of the engine and/or the current (Iheating) flowing through the heating device.

Abstract: A fuel system for an internal combustion engine (12) operated with fuel gas includes an evaporator (1) in which the liquid fuel gas is transformed by the addition of heat into a gaseous state. The evaporator (1) has a first heating device (13) configured to transmit a portion of the waste heat of the internal combustion engine (12) to the fuel gas in the evaporator (1). The evaporator (1) has a second heating device, by means of which the fuel gas in the evaporator (1) can be heated regardless of the condition of the internal combustion engine (12). The second heating device (14) can include an electrical heating element, e.g., a PTC heating element.