Aircraft anti-icing fuel system suitable for high-altitude low temperature environment

Abstract

The invention discloses an aircraft anti-icing fuel system suitable for high-altitude low temperature environment. A fuel filter in the fuel system is an irregular rectangular structure with top being a bevel of 45 degrees, adopts aluminum alloy framework and is welded by externally covered filter screens with filter fineness of 50mu; the fuel in a fuel tanker enters a consumption tank after being filtered by the fuel filter; return fuel in an engine evenly flows down through the fuel filter from the top of the fuel filter by passing through a horizontal pipe which is installed at the top of the fuel filter and is provided with small holes; the heat of the return fuel is adopted to melt ice crystals which probably remain on the surface of the fuel filter; impurities such as gum formed by moisture, ice crystals or oxide in the fuel flow to a consumption tank sump along the surface of the fuel filter. By adopting such a special system, impurities such as ice crystals, moisture and the like in the fuel can be effectively stopped from entering a feedline of the engine, impurities such as ice crystals and the like in the fuel can be prevented in real time from blocking the fuel pump and carburetor of the engine, and the engine can be ensured to work safely under high-altitude low temperature environment for long time.

Description

technical field [0001] The invention belongs to the technical field of aviation and relates to the design of an aircraft anti-icing fuel system suitable for high-altitude and low-temperature environments. Background technique [0002] The function of the aircraft fuel system is to store fuel and supply fuel to the engine stably and smoothly as needed under the specified flight status and altitude. The fuel system of the aircraft mainly includes the fuel tank (including the consumed fuel tank), the fuel supply system, the fuel delivery system (sometimes including the fuel return system), the ventilation system, the fuel measurement system, the gravity refueling, and the fuel discharge part, etc. [0003] For aircraft fuel, aviation kerosene is generally used. Anti-icing agent is added during flight and the fuel pump adopts electric heating to prevent freezing, so as to ensure flight safety. However, sometimes due to the high water content of the fuel, the electric heating pow...

AI Technical Summary

Problems solved by technology

This kind of gasoline often contains a certain amount of dissolved water (about 200-1000ppm) in the smelting process, which will gradually precipitate out as the temperature drops in high-altitude and low-temperature environments and become free water. Freeze to form ice crystals and block the fuel filter. When the fuel is delivered through the fuel filter, it will not only freeze the surface of the oil filter, but also form new ice crystals on the pores of the oil filter, that is, crystal nuclei, and form a solid around it. When the ice crystals enter the fuel system pipeline, the ice crystals will block the fuel pump and carburetor oil holes, resulting in poor fuel supply system, resulting in abnormal operation of the fuel system and engine, affecting flight safety

During the flight, due to the freezing of free water in the gasoline, the low-pressure pressure switch of the fuel pipeline caused the alarm and the engine speed was unstable. have ice crystals

[0004] The oil filters directly installed in most aircraft fuel systems are not anti-icing. There are certain ways to prevent freezing by using fuel pump heating method to melt ice crystals, or improving filter accuracy, and installing bypass valves on oil filters. limitation:

[0005] (1) The saturated vapor pressure of gasoline is high, and it is easy to volatilize in the environment of high altitude and low pressure, which will cause steam blockage and affect the normal operation of the fuel pump;

[0006] (2) The size of the fuel filter screen is limited by the structural size of the consumed fuel tank;

[0007] (3) Installing a bypass valve on the oil filter will increase the structural weight

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