A low temperature fuel tank inerting system and its working method

Abstract

The invention discloses a low-temperature fuel tank inerting system and a working method, belonging to the technical field of explosion-proof fuel tanks of aircraft; the invention utilizes the pressure of nitrogen-rich gas at the outlet of a hollow fiber membrane air separation device, adopts a three-wheel booster structure, and passes through the hollow fiber membrane The nitrogen-enriched gas at the outlet of the air separation device is used to drive the cooling turbine. The work recovered by the turbine drives the fan to cool the bleed air of the engine, and at the same time increases the inlet pressure of the hollow fiber membrane air separation device. The low-temperature nitrogen-enriched gas obtained from the expansion of the cooling turbine The gas enters the fuel tank, which reduces the temperature of the fuel while achieving inertness, further improving the safety of the fuel tank. The invention not only improves the inlet pressure of the hollow fiber membrane air separation device, solves the problem of low efficiency of the membrane separation device due to insufficient bleed air pressure of the engine compressor under some working conditions, but also reduces the temperature at which the nitrogen-rich gas enters the fuel tank, effectively The flammability exposure time of the fuel tank is accurately controlled, and the safety of the fuel tank is improved.

Description

technical field [0001] The invention belongs to the technical field of fuel tank explosion protection, and in particular relates to a low-temperature fuel tank inerting system and a working method thereof. Background technique [0002] The combustion and explosion of aircraft fuel tanks will pose a great threat to flight safety, accompanied by huge economic losses and adverse social impacts. Fuel tank explosions have been a recurring problem associated with the design and use of aircraft fuel systems since powered flight. In order to solve this problem, the FAA has revised the airworthiness requirements for fuel tank ignition protection of civil transport aircraft three times, from the initial requirement that the maximum temperature of the fuel in the fuel tank be lower than the minimum auto-ignition temperature of the fuel with a safety margin, to the latest The acceptable flammability exposure time is required in the airworthiness clauses, and the requirements for the ex...

AI Technical Summary

Problems solved by technology

[0005] The invention discloses a low-temperature fuel tank inerting system aiming at the defects in the prior art of reduced safety, low efficiency of the hollow fiber membrane separation device or even failure to work, etc., and the invention fully utilizes the law of pressure variation in the inert system , which solves the problems in the prior art

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