Method of operating anti-icing valve

Abstract

A unique anti-icing management system for a gas turbine engine is disclosed according to which, at all times, only the required amount of heat is applied to inlet surfaces of the engine to prevent the formation of ice. Heated air is bled from the compressor discharge for this purpose and the amount of flow of the heated air is adjusted by a uniquely operated solenoid valve under the direction of an electronic control responsive to any one of a variety of meaningful conditions including, but not necessarily limited to, temperature of an anti-iced surface at the inlet to the engine, rotational speed of the engine, and the presence of an ice producing meteorological condition. The solenoid valve assumes only two operable positions, namely, a fully open position and a fully closed position, and is operated in a pulsed fashion to control flow on a time basis, rather than on a percentage-of-opening basis which is the conventional mode of operation. A switching operation or mechanism within the electronic control, such as a microprocessor, is responsive to any of the aforementioned conditions to cause the solenoid valve to pulsate according to a predetermined pattern which assures a minimally sufficient flow rate of heated air to the regions to be heated.