SU1726090A1 - Method of burning fuel - Google Patents

Abstract

The invention relates to the combustion of liquid fuel in the combustion chambers of gas turbines. In start-up and low-power modes, a portion of low-pressure air is ejected by combustion products and the degree of spraying is controlled by the amount of fuel supplied for combustion, and the fuel is sprayed by an ejected stream of low-pressure air. 1 il.

Description

The invention relates to energy and can be used, in particular, when burning fuel in the combustion chambers of gas turbines.

There is a method of burning fuel by spraying fuel with low-pressure air followed by ignition from a pilot burner.

The disadvantages of this method are the unsatisfactory quality of fuel atomization at start-up and low completeness of combustion.

The closest in technical essence to the present invention is a method of burning fuel by spraying fuel into the combustion chamber with low-pressure air with subsequent intensification of combustion by a pulsating flow of combustion products.

The disadvantages of this method are low combustion efficiency and the complexity of organizing the control of spraying, mixing and burning processes when changing operating modes.

The purpose of the invention is to increase the combustion efficiency of liquid fuels at startup and low power modes.

To do this, at start-up and low-power modes, a part of low-pressure air is additionally ejected by combustion products and the degree of atomization is controlled by the amount of fuel supplied for combustion, and the atomization of fuel is produced by the ejected low-pressure air stream.

In start-up and low-power modes, a part of low-pressure air is additionally ejected by combustion products and the degree of atomization is controlled by the amount of fuel supplied for combustion, and the atomization of fuel is produced by an ejected low-pressure air stream. This leads to an increase in the completeness of the combustion of fuel and a better mixture formation, which favorably affects the efficiency of the operation of the combustion chamber. Controlling the degree of atomization by the amount of fuel supplied to the pulsating combustion chamber allows control of spraying processes.

with

h

Yu

СЬ

ABOUT

sQ

about

vania, mixture formation and combustion of fuel in the chamber. This allows spraying processes at an optimum amplitude of pressure fluctuations, depending on the pressure of low-pressure air and the amount of fuel sprayed, and, moreover, to intensify the combustion processes in the combustion chamber. The invention makes it possible to maintain the completeness of combustion approximately constant regardless of the mode of operation.

The drawing shows a combustion chamber for carrying out the proposed method. The combustion chamber for the implementation of the proposed method of burning liquid fuel contains a combustion chamber 1 with a sawing device 2 installed at it, at the outlet of which stabilizer 3 is installed. Coaxially the spraying device 2 accommodates an aerodynamic valve 4 of the pulsating combustion chamber 5 equipped with a fuel injector 6 and a booster 7. The resonant tube 8 of the pulsating combustion chamber 5 is connected to the inlet device of the combustion chamber 1. The fuel for combustion is supplied to the spraying device 2 through the fuel tank. cash 9.

When starting the combustion chamber 1, low-pressure air enters through the aerodynamic valve 4 into the pulsating combustion chamber 5, mixes with the fuel supplied by the fuel injector 6, and the resulting air-fuel mixture ignites from the igniter 7. The pulsating flow of products exhausts from chamber 5 through the aerodynamic valve 4, mixes with low-pressure air and enters the spraying device 2, additionally ejecting part of low-pressure air. The resulting stream sprays and heats the fuel supplied through the fuel channel 9 to the spray device 2. The fuel-air mixture enters chamber 1 and ignites from products emanating from the resonant tube 8 of the pulsating combustion chamber 5. The combustion process starts, supported by the installed stabilizer 3 and intensified by a pulsating flow of products flowing from the resonance tube 8. As the amount of fuel supplied to the chamber 5 of the fuel injector 6 increases, the amplitude of pressure fluctuations of the products flowing from the aerodynamic valve 4 and the resonance tube increases eight.

With an increase in pressure of low-pressure air and operation at low power modes, the amount of fuel is reduced.

pulsating combustion chamber 5, however, the spraying and heating of the fuel is carried out as at the start.

When operating at higher power modes, the fuel supply to the chamber 5 is stopped, its operation is stopped, and the fuel is sprayed out with high-pressure cycle air through the spray device 2.

10 When reducing the load, chamber 5 is put into operation and spraying, mixing and burning of fuel is carried out according to the proposed method.

Positive effect at the specified

15, the method of burning fuel in the combustion chamber is achieved by improving the quality of fuel atomization at start-up and operation at low power modes. A pulsating flow of products, flowing from a 20 aerodynamic valve, mixing with a stream of low pressure air and additionally ejecting a part of the flow, enters the spraying device, thereby increasing the mass flow ratio of air and fuel. This reduces the average size of the droplets of fuel, which is also facilitated by the increase in temperature and pressure of the air coming from the aerodynamic valve. In the end

30 an increase in the quality of atomization leads to an increase in the completeness of combustion of fuel by 5-10%. In addition, the change in the amount of fuel burned in the pulsating combustion chamber makes it possible to regulate the amplitude of the pressure of the products depending on the pressure of the low-pressure air entering the pulsating combustion chamber. This leads to an increase in the pressure of products flowing from

40 of the aerodynamic valve into the spraying device, and it allows to intensify by 20-30% the processes of heat and mass transfer in the combustion chamber due to the pulsating flow flowing out

45 from the resonant tube to the stabilization zone. The invention makes it possible to increase the efficiency of fuel combustion and can be used when fuel is combusted in combustion chambers of both CCD and various

50 supercharged combustion devices. The economic effect of using the proposed method of burning fuel in the combustion chamber of the GTU-20 with a capacity of 8.6 MW is about 1,600 rubles. for one unit per year.

55

Claims (1)

The invention of the method of burning fuel in the combustion chamber by spraying the fuel with low-pressure air, followed by the intensification of combustion by pulsating a flow of combustion products, characterized in that, in order to increase the efficiency of burning liquid fuel at start-up and low power modes, a portion of low-pressure fuel is additionally ejected air combustion products and control the degree of atomization of the amount supplied to the combustion of fuel, and the atomization of the fuel produced by the ejected stream of low-pressure air.