RU2190109C2 - Aircraft engine drainage system - Google Patents

Abstract

FIELD: aircraft engines. SUBSTANCE: aircraft engine drainage system includes filter, check valve and drainage cavities. Drainage system is also provided with combined drainage pipe line and adjusting units and drainage valve for estimation of total leakage. Combined pipe line is connected with above-fuel portion of aircraft fuel tank. EFFECT: enhanced saving of fuel. 1 dwg

Description

 The invention relates to the field of engine manufacturing, mainly aircraft, and can be used in sectors of the economy in which gas turbine engines with a drainage system are used.

 A known drainage system of a gas turbine engine containing drainage cavities of units, a filter, a drainage tank, a fuel pumping line, a gear pump and a fuel bypass pipe (see patent RU 2141049, IPC F 02 C 7/232, 1999).

 A disadvantage of the known drainage system is its structural complexity, the need for a pump to drain the drainage from the drainage tank and the removal of drainage outward during long-term aircraft parking, which leads to losses of up to ~ 3 tons of fuel per year per engine in use and environmental pollution.

 The technical problem solved by the invention is to significantly simplify the known drainage system and eliminate drainage outward during long-term parking of the aircraft by using the drainage pressure leaking through the seals of the aggregates from the drain cavities, as well as the pressure of the gases of the combustion chamber displacing the fuel from the starting nozzles after starting the engine and from the fuel manifold of the main circuit after turning off the engine.

 The problem is solved due to the fact that the drainage system is equipped with a combined pipeline for draining the drainage from the drainage cavities of the drive and adjustable units, connected to the fuel portion of the aircraft fuel tank and a drain valve to estimate the total leakage into the drainage.

 A schematic diagram of the drainage system of an aircraft engine is shown in the drawing. The drainage system consists of the fuel tank of the aircraft 1, a fine filter 2, drainage cavities of the drive and control units 3, 4, 5, 6, the fuel manifold of the main combustion chamber 7, the fuel distributor 8, check valves 9, 12, 16, the nozzle 10, starting nozzles 11, the starting valve 13, the drain valve 14 and the combined pipe 15.

Non-return valves 9, 12, 16 are designed to prevent drainage leaks through the starting 11 and 7 fuel nozzles during prolonged parking of the aircraft under fuel. The drain valve 14 is used to assess the total leaks and fuel leaks from each unit separately, allowing to determine the technical condition of the lip and mechanical seals of the units. The connection of the pipe 15 with the fuel portion of the fuel tank of the aircraft 1 provides
the use of drainage in the combustion chamber of the engine;
separating the drainage system from the fuel in the fuel tank of the aircraft;
exclusion of drainage outward during prolonged parking of the aircraft under fuel.

At the end of the engine start, the fuel remaining in the starting nozzles 11 under the action of gas pressure in the combustion chamber will be supplied to the combined pipe 15, and then to the fuel part of the fuel tank 1. After the engine is turned off, the fuel distributor 8 will connect the fuel manifold 7 of the main combustion chamber to the combined pipeline 15 and under the action of the gas pressure of the combustion chamber, all fuel will be displaced to the fuel element of the fuel tank 1. During operation of the engine, fuel and oil penetrated through the seal units 3, 4, 5, 6 from the drain cavities with a pressure of 3 ... 5 kgf / cm ² will merge into the combined pipeline 15, and then into the fuel tank of the aircraft 1.

 During prolonged storage of the engine under fuel in the aircraft, the hydrostatic pressures in the internal cavities of the units 3, 4, 5, 6, 8, 13 will equalize with the pressures in the drainage cavities, as a result of which leakages to the drainage will stop. Thus, all the drainage generated during operation and storage of the engine will flow into the fuel tank of the aircraft 1, followed by the use of drainage in the combustion chamber of the engine.

 In the proposed drainage system, an insignificant amount of oil will flow from the aircraft engine into the aircraft’s fuel tank, which will not lead to a decrease in the combustion characteristics of this mixture, since both working fluids are obtained from oil and they mix well with each other without the formation of precipitation and turbidity. This is confirmed by the fact that after internal engine preservation in the dead-end cavities of aggregates 3, 4, 5, 6, 8, 13, up to ~ 10% of the total volume of their internal cavities of conservation oil remains, which does not adversely affect engine performance.

 In the proposed drainage system, there is no need for a drainage tank and a device for pumping drainage from it, which will reduce the weight of the drainage system, the cost of its manufacture and eliminate drainage outward during long-term aircraft parking.

 Using the proposed technical solution will make it possible to obtain from 3 to 5 tons of fuel savings per year for one aircraft engine in operation, to eliminate environmental pollution by fuels and lubricants, and to reduce the weight and cost of manufacturing a drainage system.

Claims (1)

 Aircraft engine drainage system comprising a filter, a check valve, drainage cavities, characterized in that the drainage system is provided with a combined pipe for draining drainage from the drainage cavities of the drive and control units, connected to the fuel portion of the aircraft fuel tank, and a drain valve for estimating the total leakage drainage.