RU2568031C2 - Turbojet afterburning process 2 - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: combustion chamber houses two or three rows of nozzles. Stoichiometric fuel combustion occurs in the first and/or extra row of said nozzles. "Atmofuel" is forced to the second row of nozzles in the amount sufficient for cooling of gas downstream of the first row to the level acceptable for turbine. Thereafter, evaporated fuel is burnt in afterburner chamber in the mix with air of the engine second stage. Extra amount of fuel is injected into "atmofuel" nozzles and/or afterburner chamber nozzles to be combusted completely in the mix with the turbine second stage air.

EFFECT: higher thrust, expanded adjustment range.

3 cl

Description

The invention relates to dual-circuit turbojet engines.

A known method of afterburning a turbojet engine, mainly double-circuit, consisting in the fact that in the combustion chamber there are two consecutive rows of nozzles. In the first row, stoichiometric combustion of the fuel occurs (that is, the full use of oxygen in the incoming air), and the maximum temperature is obtained. And so that the turbine does not instantly melt, any fuel (the same kerosene, or better, liquefied methane) is supplied to the second row of nozzles in such an amount that with its vapor to cool the temperature of the gases after the first row of nozzles to a level acceptable for the turbine.

In this case, the fuel supplied to the second row of nozzles does not disappear in vain. After the turbine, gases with a large amount of evaporated and thermally decomposed into carbon and hydrogen fuels mix with the secondary air and burn out, generating a large amount of heat and creating a large draft in the jet nozzle. See my pat. No. 2474718.

At the same time, original regulation of this seemingly unregulated mode is even provided - MORE fuel than necessary is supplied to the first row of nozzles, and at the same time, incomplete combustion of the fuel to carbon monoxide occurs. In this case, the heat release will be only 73.62% of the maximum (approximately 1.36 times less). Naturally, much less fuel will be required to cool the gases. That is, much less fuel is supplied to the second row of nozzles, and maybe not even delivered at all (depending on the operating temperature of the turbine). That is, within 73.62% of the maximum afterburner, you can reduce this afterburner mode. The carbon monoxide obtained after incomplete combustion also does not disappear in vain - it also burns out in the afterburner in a mixture with secondary air.

This mode is called “atmosphere” (from the Greek “atmosphere” - evaporation). The fuel that is injected into the second row of nozzles and intended primarily for evaporation is called “fuel”, and the fuel supplied to the first row of nozzles or into an additional row of nozzles (before the first) and designed to achieve stoichiometric composition is called “stoichiofuel ".

It is clear that it is advisable to choose the bypass ratio of such an engine so that the amount of air in the second circuit is sufficient to completely burn all the fuel or at least to burn the hydrogen produced from it. But if for some reason it is not possible to obtain such a bypass ratio, another way to regulate the atmospheric mode of this engine is provided by injecting an additional amount of an oxidizing agent, for example, a solution of nitrogen pentoxide in nitric acid, into the afterburner. This will increase traction for a short time.

But if the bypass ratio of such an engine can be obtained more than is necessary for the complete combustion of fuel oil, then there is one more possibility.

The objective and technical result of the invention is to increase engine thrust and expand the limits of its regulation.

If the bypass ratio of the engine is greater than necessary for the complete combustion of the fuel, then additional fuel is injected into the nozzles for the fuel and / or the nozzles of the afterburner with the possibility of its complete combustion in the mixture with the air of the second engine circuit.

However, it is possible to obtain a thrust even greater - even if the bypass ratio of the engine is greater than necessary for the complete combustion of the fuel, an additional amount of oxidizer is injected into the afterburner and / or into the air of the second circuit of the engine, and into the nozzles for the fuel and / or fuel afterburner nozzles inject an additional amount of fuel with the possibility of its complete combustion in a mixture with secondary air and with an additional oxidizing agent.

Since in this case the cooling of gases after the first row of nozzles, that is, after the supply of stoichiofuel, becomes better, it is possible to supply an additional amount of fuel and the corresponding amount of oxidizer to the region of the first row of nozzles (no more) until the turbine reaches the permissible value for the turbine temperature.

A method is implemented, for example, as follows: fuel is injected into the nozzles for fuel oil (preferably methane - it contains a higher content of bound hydrogen) more than is necessary for cooling gases after the combustion of "stoichiofuel". This fuel evaporates, passes the turbine, mixes with the air of the second engine circuit and burns completely in the afterburner. If at the same time an additional oxidizing agent was supplied to the air of the secondary circuit or to the afterburner, then more fuel is supplied.

Claims (3)

1. The method of afterburner of a turbo engine, which consists in the fact that in the combustion chamber there are two or three consecutive rows of nozzles, in the first and / or additional row of which stoichiometric combustion of fuel occurs, and the “second fuel” is supplied to the second row of nozzles in such an amount as to cool the temperature of the gases after the first row of nozzles to a level acceptable for the turbine, after which the evaporated fuel burns in the afterburner in a mixture with the air of the second circuit of the engine, characterized in that when the bypass ratio is d igatelya more than necessary for complete combustion "atmotopliva" a nozzle "atmotopliva" and / or the afterburner nozzle injected additional fuel with the possibility of complete combustion in admixture with a second air circuit of the engine. 2. The method according to p. 1, characterized in that an additional amount of oxidant is injected into the afterburner and / or into the air of the second engine circuit, and an additional amount of fuel is injected into the injectors for “fuel oil” and / or into the afterburner nozzles with the possibility of its complete combustion in a mixture with secondary air and with an additional oxidizing agent. 3. The method according to p. 2, characterized in that an additional amount of fuel and an appropriate amount of oxidizing agent corresponding to it, but not more, are supplied to the area of the first row of nozzles until the temperature in the combustion chamber is reached that is acceptable for the turbine.