| 摘要 |
<p>A fuel system (10) comprises a tank (12), a pump (14), heat exchangers (16 & 18) and a filter (20) in series fluid flow relationship. A fuel metering unit (24) returns a proportion of the filtered fuel to the tank (12) and is controlled by the engine electronic control (30). The system (10) operates so that fluid is not returned to the tank (12) when a pressure differential of the order of 5psi is detected across the fluid filter (20) and the temperature of the fluid is below 0 DEG C. The fluid is not returned to the tank (12) for a period of time to reduce the flow of fluid passing through the heat exchangers (16 & 18). The reduced flow of fluid passing through the heat exchangers (16 & 18) is heated to a temperature sufficient to melt any solidified impurities blocking the fluid filter (20). <IMAGE></p> |
