Flow control for on-board inert gas generation system
AssigneeHamilton Sundstrand Corporation
InventorEric Surawski
Life of this patent
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Abstract
An on-board inert gas generating system includes a flow control valve modulated according to changes in ambient conditions to minimize changes to oxygen content within a fuel tank. The quality of the nitrogen-enriched air stream that is provided by the air separation module varies in response to flow. Higher flow rates through the air separation module removes less oxygen relative to lower flow rates. The amount of flow through the air separation module that produces the least amount of oxygen within the fuel tank is determined for an ambient pressure and provided by modulating the flow control valve.
Claims13
A method of controlling oxygen content within and aircraft fuel tank ullage, said method comprising the steps of:
- (a) determining a rate of change in oxygen content within the fuel tank ullage based on atmospheric pressure and temperature of an environment outside of the aircraft and external of the fuel tank ullage, wherein the atmospheric pressure and temperature of the environment outside of the aircraft and the fuel tank ullage are measured by sensors disposed outside of the fuel tank ullage;
- (b) determining a desired flow rate of nitrogen-enriched air required to minimize oxygen content within the fuel tank ullage based on the atmospheric pressure and temperature of the environment outside of the aircraft and external to the fuel tank ullage;
- and
- (c) controlling an actual flow rate of nitrogen-enriched air responsive to said determination of said desired flow rate of nitrogen-enriched air by modulating a control valve disposed between an air separation unit and the fuel tank ullage.
A method of controlling oxygen content within an aircraft fuel tank comprising the steps of:
- (a) measuring an atmospheric temperature and pressure of an environment outside of the aircraft and the aircraft fuel tank;
- (b) determining a flow rate of gases into the aircraft fuel tank through a vent to the environment outside of the aircraft fuel tank utilizing the measured atmospheric temperature and pressure;
- (c) determining a flow rate of nitrogen-enriched air into the aircraft fuel tank from an air separation unit utilizing the measured atmospheric temperature and pressure;
- and
- (d) adjusting a control valve between the air separation unit and the fuel tank to control a flow rate of nitrogen-enriched gases into the aircraft fuel tank from the air separation unit to minimize an oxygen content within the fuel tank based on the measured atmospheric temperature and pressure outside the aircraft and the aircraft fuel tank.
Dependencies are inferred from the claim text.