摘要 |
<p>The present application relates to fuel flow limit calculator (12) for use with a fuel control system (30) of an engine (10) comprising a fuel delivery means (28) and a compressor (16). The fuel control system (12) seeks to control the fuel/air ratio (FAR) near the weak extinction limit of the engine (10) as calculated by the fuel flow limit calculator (12). Both the static (PS3) and total (P3) pressure are measured at the exit of compressor (16). This enables a flow reference value (Q3) to be determined so that the air mass flow (W3) can be calculated and the limiting fuel/air ratio calculated. An advantage of the present invention is that it does not require stable combustion for satisfactory operation and allows the occurrence of preferential extinction within an annular combustor (22) to be beneficially utilised. The present application also relates to a method of controlling the fuel flow (WFE) to an engine (10).</p> |