RU167336U1 - FIRE PIPE OF THE COMBUSTION CHAMBER OF A GAS TURBINE ENGINE - Google Patents

Abstract

The utility model relates to the field of engine building and can be used in combustion chambers of gas turbine engines. The technical result of the proposed utility model is to increase cooling efficiency by reducing the temperature stresses of the tubes of the flame tube by installing the bushings in the holes with a gap, and fixing them on the outer surface of the walls of the flame tube using elastic elements. The technical result is achieved by the fact that in the flame tube of the combustion chamber of a gas turbine engine, containing the outer and inner walls with rows of holes in which bushings for supplying air are connected to the walls, in contrast to the known, bushings are installed in the holes of the walls to form an annular gap, the area of which does not exceed 5% of the area of the hole, and are connected to the walls by means of elastic elements.

Description

The utility model relates to the field of engine building and may find application in the combustion chambers of gas turbine engines.

Known the flame tube of the combustion chamber of a gas turbine engine, containing the outer and inner walls with openings for air supply (S. I. Lovinsky and others. "Design and design of aircraft gas turbine engines" M. Engineering 1977 p. 104).

The disadvantage of this design of the flame tube is a large temperature gradient at the holes in the flame tube, which leads to the formation of cracks at the edges of the holes (G.S. Skubachevsky Aviation Gas Turbine Engines M. Mechanical Engineering 1974 p. 378).

The closest is the flame tube of the combustion chamber of a gas turbine engine, containing the outer and inner walls with holes in which are installed air supply bushings connected to the walls (“Design and Design of Aircraft Gas Turbine Engine” edited by D.V. Chronin. M. Engineering 1989 Page 416).

With this design of the flame tube, due to the introduction of the bushings, the depth of penetration of air jets through the zones of the flame tube increases, but the stresses from the temperature gradient are not eliminated, since the bushings are rigidly connected, for example, welded to the hot walls of the flame tube. Cracks and warpage in this design appear on the bushings, heated from the walls of the flame tube due to thermal conductivity.

The technical result of the proposed utility model is to increase the cooling efficiency by reducing the temperature stresses of the tubes of the flame tube by installing the bushings in the holes with a gap, and fixing them on the outer surface of the walls of the flame tube using elastic elements.

The technical result is achieved by the fact that in the flame tube of the combustion chamber of a gas turbine engine containing the outer and inner walls with rows of holes in which there are bushes for supplying air connected to the walls, in contrast to the known bushes are installed in the holes of the walls with the formation of an annular gap, whose area does not exceed 5% of the area of the hole, and are connected to the walls by means of elastic elements.

Due to such a connection, the sleeve through which the “cold” air passes does not cool the edges of the hole and does not create a temperature gradient and thereby without warping and cracking.

The utility model is illustrated by drawings, which depict:

FIG. 1 - flame tube of a combustion chamber with bushings;

FIG. 2 - section aa of the flame tube at the installation location of the sleeve;

FIG. 3 - section of the elastic element in the installation location of the sleeve

The flame tube of the combustion chamber of a gas turbine engine (Fig. 1) contains an inner 1 and an outer 2 wall with rows of holes 3 (Fig. 2), into which sleeves 4 are installed for supplying air to the combustion zone and to the displacement zone of the combustion chamber.

Moreover, the sleeve 4 is installed in the hole 3 with the formation of an annular gap 5 (Fig. 3), the area of which is not more than 5% of the area of the hole. When the gap area is more than 5% of the hole area, the edges of the holes will be supercooled and the temperature gradient will increase. The bushings 4 are provided with elastic elements 6. The elastic element can be made integrally with the sleeve on one side and rigidly connected to the outer surface of the walls of the flame tube on the other hand.

The elastic element 6 is made, for example, in the form of a curved flat plate (Fig. 1), which is connected to the outer and inner surfaces of the walls of the flame tube at a distance from the hole 3, i.e. with the formation of open cavities that communicate with the annular gap 5. The number of elastic elements corresponds to the number of holes and depends on the size of the flame tube.

The length of the elastic element is at least two hole diameters and depends on the design features of the flame tube. This length allows the elastic elements during thermal expansion not to overlap the annular gap 5.

The flame tube of the combustion chamber of a gas turbine engine operates as follows.

Air is supplied from the compressor through the frontal device to the flame tube of the combustion chamber of a gas turbine engine, and mixed with the fuel that enters through the fuel nozzles. Then the process of ignition of the air-fuel mixture in the primary zone of the combustion chamber. Due to the complex, rapidly proceeding chemical transformation, accompanied by exothermic oxidative reactions during the combustion of the air-fuel mixture, the walls of the flame tube are heated to extremely high temperatures. The air required for combustion and the formation of a temperature field behind the combustion chamber is supplied through the bushings. The presence of an annular gap and the elastic connection of the sleeve with the wall of the flame tube allows the sleeve to expand freely in the hole of the flame tube without temperature stresses.

In addition, if there is a gap between the bushing and the opening of the wall of the combustion tube, there is no intensive heat exchange between the cold bushing and the hot wall of the heat pipe and, as a result, there is no temperature gradient near the holes (there is no large temperature difference between the sleeve and the hole).

The connection of the sleeve with the flame tube by means of elastic elements allows the element to deform as a result of thermal expansion without critical stresses with a large margin of safety. This will allow the flame tube of the combustion chamber to work for a long time with a large number of thermal vibrations (heat transfer).

Claims (1)

The flame tube of the combustion chamber of a gas turbine engine, containing the outer and inner walls with rows of holes in which there are installed air supply bushings connected to the walls, characterized in that the bushings are installed in the holes of the walls with the formation of an annular gap, the area of which does not exceed 5% of the area of the hole , and connected to the walls by means of elastic elements.