| 摘要 |
<p>A fuel metering system comprising a fuel pump (1) operable to supply fuel at high pressure to a metering valve (4) from which metered fuel is fed, in use, via a pressure raising valve (5) to a gas turbine engine, a spill valve (8) connected between the high pressure (HP) supply upstream of the metering valve (4) and low pressure (LPp), and a restrictor device (9) connected between the spill valve (8) and low pressure (LPp), the pressure (LPf) arising at or upstream of the restrictor device (9), which varies according to spill flow through the device (9) from the spill valve (8), being applied to the pressure raising valve (5), such that the pressure required to open the pressure raising valve (5) varies in response to the amount of fuel spilled by the spill valve (8). <IMAGE></p> |
