METHOD FOR PRELIMINARY PREPARATION AND COMBUSTION OF "LEAN" AIR-FUEL MIXTURE IN LOW-EMISSION BURNER Russian patent published in 2012 - IPC F23D14/02 F23C99/00 F23C1/08 F23D17/00 F23R3/28 

FIELD: power engineering.

SUBSTANCE: invention relates to areas, where processes of mixing different liquids and gases take place, including processes of carburetion of various fuels with air and burning "lean" fuel-air mixture (FAM), in particular, to development of low-emission combustion chambers (LCC) of aircraft gas-turbine engines (GTE) and stationary gas-turbine plants (GTP) on the basis of low-emission burners (LB) with preliminary preparation and burning "lean" mixtures of fluid or gaseous fuels and air. The method for preliminary preparation and burning "lean" fuel-air mixture in a low-emission burner comprises an external bushing open at both ends, which comprises a supply fuel nozzle, a circular fuel receiver and dosing perforation arranged in the end of a fuel supply line, a permeable element with preset values of porosity and dispersity made of metal, and an axial-vane swirler with a central body of turbine type, arranged downstream the permeable element, in accordance with which fuel and air are previously mixed by supplying fuel into an air crossflow under excessive pressure via dosing perforation in order to reduce ways of mixing and increasing homogeneity of the mixture, further the flow of the formed "lean" fuel and air mixture is sent via the permeable element, where main mixing of components takes place to produce a homogeneous fuel and air mixture, then the flow is accelerated and swirled in order to form a circulation zone downstream a low-emission burner through sending the "lean" mixture flow via the axial-vane swirler. The fuel is divided into the main and the auxiliary ones, the central body is a central bushing that separates the low-emission burner into two coaxial circuits: inner and outer ones, besides, the outer circuit covers the inner circuit, the central bushing is arranged in the form of a sleeve so that it is open at the inlet and closed at the outlet, the central bushing is connected to the outer bushing with the help of hollow radial blades, each bushing (outer and central) comprises a circular fuel receiver, both bushings and radial blades comprise, moreover, dosing perforation arranged at the end of the main fuel supply line, cavities of the outer and central fuel receivers and cavities of radial blades form a single fuel cavity, the entire air is supplied only into the outer circuit under pressure, the main fuel is mixed previously with air by supplying the main fuel into the air crossflow under excessive pressure via dosing perforation arranged in bushings and blades, downstream the axial-blade swirler a hollow conical stabiliser is installed coaxially with it, representing a circular truncated cone, the top of which is sent against the flow, the front end of the stabiliser is closed, and its rear end is opened, downstream the stabiliser as a poorly streamlined body, an additional circulation zone is formed with substantially smaller dimensions compared to the main circulation zone, by means of supplying the "lean" fuel-air mixture to this stabiliser, the auxiliary fuel is supplied along the central bushing, further it is distributed in the form of a system of single jets, and is simultaneously accelerated by means of its passage via dosing perforation arranged in the end of the line of this fuel supply, and is then supplied under excessive pressure into an additional circulation zone of a stabiliser, where this fuel is mixed with the "lean" fuel-air mixture available in it.

EFFECT: invention makes it possible to increase efficiency of fuel and air mixing processes, reliability and operational life of burners, range of stable burning of lean FAM by air excess factor in case of lower pressure losses and emission of hazardous substances.

15 cl, 14 dwg