RU2261399C2 - Ring combustion chamber - Google Patents

Abstract

FIELD: combustion chambers.

SUBSTANCE: ring combustion chamber comprises front device, a number of mixing devices, and inner and outer housings of combustion chamber that are composed of the front and back sections. The front sections of the inner and outer housings of the combustion chamber define precombustion chamber diffuser, and their back sections lined with the heat-resistant plates define the flame tube of the combustion chamber. The walls of the precombustion chamber diffuser are step and provided with steps directed counter air flow. The steps are provided with openings that connect the precombustion chamber diffuser with the space between the heat-resistant plates and back sections of the outer and inner housings of the combustion chamber. The front device is made of perforated shield provided with openings for mixing devices and supplying additional air. The shield is secured within the butt between the front and back sections of one of the housings of the combustion chamber with the use of bolts for permitting free radial thermal expansion in the butt of the front and back sections of the second housing of the combustion chamber.

EFFECT: enhanced efficiency.

1 cl, 1 dwg

Description

FIELD OF TECHNOLOGY

This invention is applicable in the energy and aviation sectors, primarily in the field of gas turbine construction.

BACKGROUND

A technical solution is known using the so-called multi-channel precamera diffuser [V.A. Palkin, "US Program for the Creation of New Aircraft Engine Technologies", p. 29, "Conversion in Mechanical Engineering", No 2 (57) March-April 2003, Moscow, "Informconversion"], which reduces the level of pressure loss. A short pre-chamber diffuser with a large diffusivity coefficient is made divided into several annular channels, in each of which a low value of the diffusivity coefficient is realized. This solution reduces pressure losses from secondary flows arising due to the pressure gradient in the boundary layer, however, friction losses increase due to an increase in the surface area in contact with the air flow.

A technical solution is also known [Patent No. 2373319, Great Britain IPC7 F 23 R 3/00, 3/06, Application No. 0105931.0, claimed. 03/12/2001, published. September 18, 2002], aimed at reducing the air flow rate for cooling the combustion tube of the combustion chamber through the use of heat-resistant tiles to form the combustion tube, selected as a prototype. The combustion chamber has an inner and outer housing of the combustion chamber, including front and rear compartments. The front compartments of the housings form a precamera diffuser, and their rear compartments, lined with heat-resistant tiles (elements), form the heat pipe itself, at the entrance to which there is a front-mounted device with many mixing devices. Between the heat-resistant tiles and the rear compartments of the bodies of the combustion chamber, cavities are formed for the passage of secondary air that goes to cool the flame tube.

SUMMARY OF THE INVENTION

Due to the continuous increase in temperature and air velocity at the inlet to the combustion chamber, with an increase in the temperature of the gases at its outlet, the organization of fuel combustion at a near stoichiometric value of the coefficient of excess air presents very stringent requirements for the development of new combustion chambers, which requires new approaches to their design. Of particular importance is the optimization of the elements of the combustion chamber, which determine its effectiveness.

When creating this invention solves the problem of expanding the arsenal of technical means aimed at improving the efficiency of the combustion chamber at near stoichiometric values of the coefficient of excess air; The technical result consists in the implementation of this purpose.

The essential features characterizing the invention:

Front device many mixing devices; internal and external housing of the combustion chamber; pre-chamber diffuser; front and rear compartments of the bodies of the combustion chamber; heat resistant tiles; flame tube.

Salient Features:

Stepped walls of the precamera diffuser with ledges oriented towards the air flow; ledges with holes communicating the pre-chamber diffuser with a cavity between the heat-resistant tiles and the rear compartments of the outer and inner bodies of the combustion chamber; front-mounted device in the form of a perforated screen with holes for mixing devices and the supply of additional air; a screen fixed at the junction between the front and rear compartments of one of the combustion chamber housings by means of a bolt joint and ensuring freedom of radial thermal expansion at the joint of the front and rear compartments of another combustion chamber housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing shows a longitudinal section of an annular combustion chamber.

DETAILED DESCRIPTION OF THE INVENTION

The annular combustion chamber consists of front 1 and rear 2 compartments of the outer casing, front 3 and rear 4 compartments of the inner casing, front device 5 and a plurality of mixing devices 6. The front compartments of the outer and inner casings, 1 and 3, respectively, form a pre-chamber diffuser 7, wherein its walls are made stepped with ledges 8, oriented towards the air flow, and holes 9 are made in these ledges.

The rear compartments of the outer and inner bodies, 2 and 4, respectively, are lined with heat-resistant tiles 10 and 11 (with inclined openings for cooling air), forming a flame tube 12 of the combustion chamber.

In the joints between the front and rear compartments of the outer and inner bodies of the combustion chamber, a front device 5 is fixed in the form of a perforated screen with holes for mixing devices and holes 13 for supplying additional air. The front-mounted device is fixed in one joint by means of a bolted connection, and in the other, with the freedom of radial thermal expansion. Between the heat-resistant tiles 10, 11 and the rear compartments of the outer and inner bodies of the combustion chamber there are cavities 14 and 15 for the passage of secondary air. The holes 9 in the ledges of the pre-chamber diffuser 7 communicate with the cavities for the passage of secondary air.

During operation of the combustion chamber, air from the pre-chamber diffuser enters the flame tube 12:

- main - through mixing devices, where it is mixed with fuel;

- additional - through holes in the front device;

- secondary - through holes in the ledges of the pre-chamber diffuser and holes in heat-resistant tiles.

The primary and secondary air are involved in the combustion of fuel, and the secondary is used to cool the combustion chamber bodies and heat-resistant tiles of the flame tube. Thus, pressure losses in the pre-chamber diffuser are reduced, and a velocity field is formed in it, which is necessary for the efficient operation of the combustion chamber.

Claims (2)

1. An annular combustion chamber, including a front-end device, a plurality of mixing devices, an inner and an outer housing of the combustion chamber, consisting of front and rear compartments, the front compartments of the inner and outer casings of the combustion chamber forming a pre-chamber diffuser, and their rear compartments lined with heat-resistant tiles, form the flame tube of the combustion chamber, characterized in that the walls of the pre-chamber diffuser are made stepwise, with ledges oriented towards the air flow, and in these ledges The openings are made, communicating the pre-chamber diffuser with a cavity between the heat-resistant tiles and the rear compartments of the outer and inner combustion chamber bodies. 2. The annular combustion chamber according to claim 1, characterized in that the frontal device is made in the form of a perforated screen with holes for mixing devices and the supply of additional air, fixed in the junction between the front and rear compartments of one of the combustion chamber bodies using a bolted connection and fixed with the freedom of radial thermal expansion at the junction of the front and rear compartments of another housing of the combustion chamber.