JPH0693929A - Jet engine - Google Patents

Abstract

(57) [Summary] [Purpose] Even when a jet aircraft drastically changes the flight direction, the air-fuel ratio, which is the ratio of fuel to compressed air in the afterburner, is maintained at a predetermined value. [Structure] A plurality of pressure detectors 15 are provided on the outlet side of the fan and the low-pressure compressed air 2 in the circumferential direction of the casing 14, and the arithmetic and control unit 16 is based on the air pressure P detected by the pressure detector 15. The valve opening degree command V is obtained so that the air-fuel ratio between the fuel flow rate and the air flow rate injected from the fuel injection bar 9 of the afterburner 7 becomes a predetermined value, and by the valve opening degree command V,
The opening degree of the control valve 13 for controlling the flow rate of the fuel F sent to the fuel injection bar 9 is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jet engine.

[0002]

2. Description of the Related Art In a jet aircraft equipped with a jet engine with an afterburner, when the flight direction is suddenly changed such as a sharp turn or a rapid ascent, a drift in the air flow occurs at the engine inlet, which results in an afterburner. The air-fuel ratio may fluctuate, and unstable combustion such as flame blowout may occur.

[0003]

However, it is the actual situation that the above-mentioned measures against the unstable combustion have not been taken conventionally.

In view of the above situation, the present invention prevents unstable combustion such as flame blowout in the afterburner portion even when a jet plane equipped with an afterburner jet engine suddenly changes direction. It was made for that purpose.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a fan and low pressure compressor for compressing the introduced air, a high pressure compressor for further compressing a portion of the compressed air from the fan and low pressure compressor, and a fuel. A combustor for combusting the air with compressed air from a high pressure compressor to generate combustion gas; a turbine rotated by the combustion gas from the combustor and driving the fan and the low pressure compressor and the high pressure compressor; Among the compressed air from the fan and the low-pressure compressor, a duct that guides the remaining compressed air that is not introduced into the high-pressure compressor, and the combustion gas from the turbine and the compressed air from the duct are introduced and the combustion gas is ejected from the rear end. The afterburner duct and the plurality of afterburner ducts arranged radially in the afterburner duct and injecting fuel into the afterburner duct. And afterburner having a fuel spray bar, in a jet engine comprising a control valve for controlling the flow rate of the fuel injected from the respective provided and each fuel spray bar to the conduit for feeding fuel to each fuel injector bar,
A plurality of pressure detectors arranged radially behind the fan and the low-pressure compressor when viewed from the axial direction and capable of detecting the pressure of the compressed air sent from the fan and the low-pressure compressor, and the respective pressure detectors. It is provided with an arithmetic and control unit for obtaining a valve opening degree command corresponding to the air pressure based on the air pressure detected by the detector and giving it to a control valve corresponding to the pressure detector.

[0006]

The pressure of compressed air from the fan and the low-pressure compressor is detected by the pressure detector and sent to the arithmetic and control unit. The arithmetic and control unit obtains a valve opening command corresponding to the air pressure and opens the valve. The degree command is given to the control valve for controlling the flow rate of the fuel injected from the fuel injection bar into the afterburner duct, and the control valve is controlled to the opening degree corresponding to the detected air pressure. Therefore, the air-fuel ratio between the fuel injected from the fuel injection bar into the afterburner duct and the compressed air introduced into the afterburner duct is always maintained at a predetermined value.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of a jet engine of the present invention. In the figure, 1 is an air intake port provided at the tip of the jet engine, 2 is a fan and a low pressure compressor provided immediately after the air intake port, 3 Is a high pressure compressor disposed behind the fan and the low pressure compressor 2, 4 is a combustor disposed behind the high pressure compressor 3, 5 is a turbine disposed behind the combustor 4, 6 is a fan and low pressure From the rear of the compressor 2 to the rear end of the turbine 5,
An annular duct provided so as to surround the high-pressure compressor 3, the combustor 4, and the turbine 5, and an afterburner 7 disposed behind the turbine 5.

The afterburner 7 has an afterburner duct 8 whose outer periphery extends to the outer periphery of the rear end of the duct 6, and a turbine 5.
A plurality of fuel injection bars 9 which are located immediately after the fuel injection rod 9 and are radially arranged in the afterburner duct 8 when viewed from the axial direction D, and whose tips are inserted into the afterburner duct 8. A pipe that includes a plurality of flame holders 10 arranged corresponding to the injection bars 9 and a nozzle 11 arranged at the rear end of the afterburner duct 8 and that supplies the fuel F to the fuel injection bars 9. A control valve 13 is attached to each of the passages 12.

The casing 14 of the fan and the low-pressure compressor 2.
At the rear end, a plurality of pressure detectors 15 for detecting the pressure of the low-pressure compressed air A sent from the fan and the low-pressure compressor 2 are radially arranged when viewed in the axial direction D and the pressure detectors 15 are arranged. The air pressure P detected in 1 can be given to the arithmetic and control unit 16.

Further, the arithmetic and control unit 16 can give a valve opening command V corresponding to the detected air pressure P to the control valve 13.

One pressure detector 15 may be provided corresponding to one fuel injection bar 9, or one pressure detector 15 may be provided corresponding to a plurality of fuel injection bars 9. Is also good. In the figure, G and G _M are combustion gases,
A'is compressed air.

The air introduced into the fan and the low-pressure compressor 2 from the air intake 1 during the flight of the jet is compressed by the fan and the low-pressure compressor 2 driven by the turbine 5 into the low-pressure compressed air A, which is partially Is introduced into the high-pressure compressor 3, further compressed, and introduced into the combustor 4 as high-pressure compressed air. In the combustor 4, the fuel injected from the fuel injection nozzle (not shown) is burned by the high-pressure compressed air from the high-pressure compressor 3 to generate the combustion gas G, which is burned. It is introduced from the device 4 into the turbine 5 to drive the turbine 5, discharged from the turbine 5 and introduced into the afterburner duct 8.

On the other hand, of the compressed air A generated by the fan and the low pressure compressor 2, the compressed air A flowing into the duct 6 is
The high-pressure compressor 3 and the combustor 4 as well as the turbine 5 are cooled, heated and introduced into the afterburner duct 8.

In the afterburner 7, the fuel F injected from the fuel injection bar 9 through the pipe 12 is burned by the compressed air A and mixed with the combustion gas G to generate the combustion gas G _M , and the combustion gas G _M passes through the afterburner duct 8 and is discharged from the nozzle 11 to obtain thrust. The flame formed by the combustion of the fuel F injected from the fuel injection bar 9 is held by the flame holder 10.

A part of the compressed air A from the duct 6 flows along the inner circumference of the afterburner duct 8 to cool the afterburner duct 8.

Further, during flight of the jet aircraft, the pressure of the compressed air A sent from the fan and the low pressure compressor 2 is detected by the pressure detector 15 and given to the arithmetic and control unit 16 as the air pressure P. At 16, the air flow rate Q corresponding to the air pressure P is obtained and the air flow rate Q
The fuel flow rate W is calculated based on the above so that the air-fuel ratio Q / W becomes substantially constant, and the valve opening command V corresponding to the calculated fuel flow rate W is calculated.
Is calculated, and the calculated valve opening command V is calculated by the calculation control device 1
It is output from 6 and given to the control valve 13, and the control valve 13 adjusts to a predetermined opening degree.

In this case, when the jet aircraft is traveling straight, the air pressure P detected by any pressure detector 15 has a substantially constant value, so that the control valves 13 have substantially the same opening degree.

However, when the jet plane suddenly changes its flight direction such as a sharp turn or a rapid rise, the air introduced from the air intake port 1 into the fan and the low-pressure compressor 2 causes a non-uniform flow, and the pressure detector 15 The air pressure P detected by means of the pressure detector 15 also varies depending on the position of the pressure detector 15. Therefore, the valve opening command V output from the arithmetic and control unit 16 also differs depending on the control valve 13, and the control valve 13 is adjusted to different opening depending on the position, so that the air-fuel ratio is kept substantially constant.

For example, in FIG. 1, when the jet suddenly rises diagonally upward to the left, the air pressure P detected by the pressure detector 15 on the lower side in FIG. 1 is detected by the pressure detector 15 on the upper side. 1, the opening degree of the control valve 13 on the lower side in FIG. 1 becomes larger than the opening degree of the control valve 13 on the upper side.

As described above, even when the jet aircraft drastically changes the flight direction, the air-fuel ratio in the afterburner 7 can be made substantially constant, so that there is no variation in the air-fuel ratio in the afterburner 7 part. Unstable combustion such as flame blowout does not occur.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without departing from the gist of the present invention.

[0023]

According to the jet engine of the present invention, the fuel injected from the fuel injection bar of the afterburner and the air-fuel ratio of the compressed air from the fan and the low pressure compressor can be maintained at a predetermined value at all times. Even when the jet plane suddenly changes the flight direction, it is possible to prevent unstable combustion such as flame blowout, prevent a decrease in thrust, and other excellent effects.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view including a control system of an embodiment of a jet engine of the present invention.

[Explanation of symbols]

2 Fan and Low Pressure Compressor 3 High Pressure Compressor 4 Combustor 5 Turbine 6 Duct 7 Afterburner 8 Afterburner Duct 9 Fuel Injection Bar 12 Pipeline 13 Control Valve 15 Pressure Detector 16 Computation Control Device P Air Pressure A Compressed Air G Combustion Gas G _M Combustion gas F Fuel V Valve opening command D Axial direction

Claims (1)

[Claims] 1. A fan and a low-pressure compressor for compressing the introduced air, a high-pressure compressor for further compressing a part of the compressed air from the fan and the low-pressure compressor, and compressed air from the high-pressure compressor for fuel. And a turbine that is rotated by the combustion gas from the combustor and that drives the fan and the low-pressure compressor and the high-pressure compressor, and the compression from the fan and the low-pressure compressor. A duct that guides the remaining compressed air of the air that is not introduced into the high-pressure compressor, an afterburner duct that allows the combustion gas from the turbine and the compressed air from the duct to be introduced, and eject the combustion gas from the rear end, and An AF having a plurality of fuel injection bars arranged radially in the afterburner duct as viewed in the axial direction and for injecting fuel into the afterburner duct. A jet engine equipped with a tabener and a control valve for controlling the flow rate of fuel injected from each fuel injection bar, which is provided in a pipe for supplying fuel to each fuel injection bar. A plurality of pressure detectors arranged radially behind the shaft of the fan and capable of detecting the pressure of the compressed air sent from the fan and the low-pressure compressor, and the air detected by the pressure detectors. A jet engine, comprising: an arithmetic and control unit that obtains a valve opening command corresponding to the air pressure based on the pressure and gives the command to a control valve corresponding to a pressure detector.