LIQUID OXYGEN FEED SYSTEM AND METHOD OF ITS FEED FROM TANK TO CONSUMER Russian patent published in 2015 - IPC F02K9/48 F04D1/10 

FIELD: aircraft engineering.

SUBSTANCE: proposed system comprises the unit of three cascades of interconnected pumps with independent drives, tank with oxygen and oxygen consumer. System inlet is connected with fuel tank while its outlet is connected with oxygen consumer. In compliance with this invention, this system is provided with high-pressure gas source with valve, mixer and gas consumer. Gas source is connected via valve with third cascade pump drive composed by the turbine. Third cascade turbine outlet is connected with gas consumer and first and second cascade pump drive gas inlets. Said cascades are composed of axial turbines arranged coaxially with appropriate pumps and secured therewith. First and second cascade turbine gas outlets are connected via mixer with first cascade pump liquid oxygen outlet. Note here that oxygen feed channels in first and second cascade pumps extend in diagonal and have axial inlets and outlets while third cascade pump is a rotary design. Method of liquid oxygen feed from tank to consumer consists in that oxygen is fed from tank to first cascade pump. Therefrom, oxygen is fed to second cascade pump. Therefrom, oxygen is fed to third cascade pump. Oxygen from third cascade pump is fed to consumer. Note here that first cascade pump oxygen pressure is increases with due allowance for second cascade pump cavitation-free operation. Liquid oxygen pressure in second cascade pump is increased to supercritical level. Maximum permissible rpm is set for third cascade pump. High pressure gas is fed from compressed gas source to third cascade turbine inlet. Gas energy is converted in third cascade turbine with pressure decreased into mechanical power. At third cascade turbine outlet gas is fed to consumer and to inlet of first and second cascade turbines. Gas energy is converted in first and second cascade turbines into mechanical power at decreased pressure to release this gas into mixer. Wherein this gas is mixed with oxygen flow forced from first cascade pump. Oxygen pressure upstream of third cascade pump is set higher than oxygen critical pressure by not over 10%. Third cascade pump rotor rpm is selected proceeding from rotor intensity parameter B defined by relationship B=N_pn², where N_p is pump output, n is rotor rpm. Second cascade pump rotor rpm is set higher than that of first cascade pump rotor.

EFFECT: higher efficiency, decreased weight, higher reliability.

6 cl, 1 dwg