APPARATUS FOR REGULATING AIR BYPASS FROM COMPRESSOR OF AUXILIARY POWER UNIT Russian patent published in 1999 - IPC

FIELD: power equipment. SUBSTANCE: apparatus has air bypass valve with pneumatic drive, jet control unit and pressure ratio setter, whose input channel is in communication with full pressure source of measuring device and output channel is in communication with one of input channels of comparison element, whose other input channel is connected with pressure source, and output channels are connected through amplifier to pneumatic drive cavities. Amplifier feeding nozzle is connected with output of logic element, whose second output channel is connected through amplifier with one cavity of pneumatic drive, one control channel is connected with narrow part of shaped nozzle and other control channel is connected with low pressure source. Auxiliary channel is provided between output channels in logic element and connected via throttle to narrow part of nozzle. In the process of starting and at low-duty operation of auxiliary power unit, high-pressure signal is generated at jet control unit output to block air bypass valve in its closed position, with comparison elements being switched off. At working modes, comparison element blocking is released, and signal indicative of air bypass through bypass channel is generated in output channels of jet control unit. Such construction of apparatus allows signal value at which air bypass valve is blocked out from closed position to be reduced. EFFECT: increased efficiency and enhanced reliability in operation. 2 cl, 3 dwg