System for injecting bypass air to decrease air film cold air temperature of aero-engine

Abstract

The invention provides a system for injecting bypass air to decrease the air film cold air temperature of an aero-engine. The system comprises a high-pressure cooling working medium storage container,a buffer mixing chamber, a suction opening, an air film cold air injection opening, an injector, a first controller and a second controller; the suction opening is formed in the wall surface of a bypass duct of the engine; the air film cold air injection opening is formed in an outlet pipeline of the buffer mixing chamber and communicates with air film cold air inlets in a rear hot end part of the engine; high-pressure and low-pressure inlets and outlets of the injector communicate with the high-pressure cooling working medium storage container, the suction opening and the buffer mixing chamber through pipelines correspondingly, a regulating valve and a pressure and temperature sensor are arranged on a pipeline for making an outlet of the high-pressure cooling working medium storage container communicate with the high-pressure inlet of the injector, and an electromagnetic valve is arranged on a pipeline for making the low-pressure inlet of the injector communicate with the suction opening; the first controller is connected with the regulating valve, the pressure and temperature sensor and the temperature sensor; and the second controller is connected with the electromagnetic valve. By means of the injector, the rear hot end part of the engine can be cooled only through a normal-temperature cooling working medium.

Description

technical field [0001] The invention relates to a cooling system for a hot end part of an aero-engine, in particular to a cooling system suitable for film cold air of a hot-end part in an aero-engine. Background technique [0002] Aircraft infrared stealth is a problem that must be solved for future advanced aviation aircraft. Primary sources of infrared signals include hot parts of engines, exhaust plumes from nozzles, and the fuselage of the aircraft. Therefore, the current main method is to suppress the infrared signal by covering the heat-generating parts of the engine, cooling the exhaust, shrinking the plume, and using low-radiation surface coatings. [0003] The infrared signal from the rear end of the aircraft is mainly caused by the "hot parts" of the engine, that is, the center body of the nozzle, the inner wall and the rear end surface of the low-pressure turbine. The temperature of these components is between 450 and 700 °C. Especially when the engine is under ...

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Problems solved by technology

[0005] Although the use of liquid nitrogen cooling can quickly reduce the exhaust temperature and the temperature of the tail nozzle, but because the cold source is completely from low-temperature liquid nitrogen, the mass required to be carried is relatively large, and because the liquid nitrogen is in an extremely low-temperature state, the storage and maintenance costs are high

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