JPH07117214B2 - Fuel injection method for gas turbine engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fuel injection method for a gas turbine engine.

2. Description of the Related Art Generally, fuel for a gas turbine engine has a nozzle body 1 as shown in FIG. 9 and a primary injection port 3 that is housed at the tip of the nozzle body 1 and injects the primary fuel into a combustion chamber 2. A secondary tip 6 having a tip 4 and a secondary injection port 5 that is housed in the tip of the nozzle body 1 and surrounds the primary injection port 3 and that injects secondary fuel into the combustion chamber 2.
And the primary and secondary injection ports 3 provided in the nozzle body 1,
Fuel is injected into the combustion chamber 2 from a fuel injection nozzle provided with supply passages 7 and 8 for supplying fuel to the fuel injection nozzle 5. The injection is performed from the primary and secondary injection ports 3 and 5 of the fuel injection nozzle. In order to completely burn the fuel in the combustion chamber 2, the nozzle body 1 around the primary and secondary tips 4 and 6 is conventionally used.
Is provided with an air passage 9 through which air passes in the axial direction,
Air was jetted into the combustion chamber 2 from the outlet opening 10 of the air passage 9 to stir the injected fuel.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in such a fuel injection method, since the injected fuel is agitated with the air and irregularly floats in the combustion chamber 2, a part of the injected fuel is injected into the injection nozzle. The fuel adheres close to the injection ports 3 and 5 of
Since the injection nozzle is heated to a high temperature by the heat of combustion, the liquid component evaporates and carbonizes, and only the solid component remains and adheres firmly. Then, the adhesion of such carbides increases with time, and finally the injection port 3,
There is a problem that 5 may be closed.

Means for Solving the Problems Such problems are caused by imparting a circumferential swirling force to the air jetted into the combustion chamber from the outlet opening of the air passage provided around the fuel injection port, The problem can be solved by forming an umbrella-shaped air curtain around the injected fuel immediately after being injected from the fuel injection port.

Action Now, it is assumed that fuel is injected from the fuel injection port into the combustion chamber in a predetermined injection form. At this time, air is jetted into the combustion chamber from the outlet opening of the air passage provided around the fuel injection port. Since the jetting air is given a swirling force in the circumferential direction, the jetted air is An umbrella-shaped air curtain that spreads like an umbrella in the combustion chamber and does not cross-collide with the injected fuel immediately after being injected from the fuel injection port is formed. As a result, the injected fuel floatingly moving in the combustion chamber is prevented from approaching the fuel injection port of the injection nozzle, and the adhesion of the injected fuel to the injection nozzle is prevented.

Embodiment An embodiment of the fuel injection nozzle for carrying out the present invention will be described below with reference to the drawings.

In FIG. 1, 21 is a fuel injection nozzle of a gas turbine engine, and this injection nozzle 21 has a support 24 composed of a flange portion 22 and a cylindrical portion 23. A nozzle case 25 is loosely fitted in the support 24, and the nozzle case 25 has a flange portion 26 and a cylindrical portion 27. 28 is a port block, light oil in this port block 28,
A fuel passage 29 is formed through which fuel such as heavy oil is fed. The support 24, the nozzle case 25, and the port block 28 described above constitute the nozzle body 30 as a whole. A nozzle tip 42 is housed at the tip of the nozzle body 30. The nozzle tip 42 is composed of a primary tip 43 and a secondary tip 44 arranged immediately before the primary tip 43. As shown in FIGS. 1, 2, and 3, the primary tip 43 has a substantially conical primary spiral chamber 45 and a pair of swirl passages 46. On the other hand, the secondary tip 44 has a secondary swirl chamber 49 surrounding the primary swirl chamber 45 between itself and a pair of swirl passages 50, as shown in FIGS. . Since the primary and secondary fuels introduced into the primary and secondary swirl chambers 45 and 49 through the swirl passages 46 and 50 have a tangential component force, the inside of the primary and secondary swirl chambers 45 and 49. While being swirled, the fuel is injected into the combustion chamber 48 from the primary and secondary fuel injection ports 47 and 51 provided at the tips of the primary swirl chambers 45 and 49 in a predetermined injection form. In addition, the primary chip 43 is formed with a pair of passages 52 connected to the swirling passage 50. A supply block 61 shown in FIGS. 1, 6, and 7 is housed in the nozzle body 30 rearward of the nozzle tip 42, and a primary supply path 62 is formed in the supply block 61. The turning passage 46
Connected to. In addition, the supply block 61 includes a secondary supply path 64.
Is formed, and the secondary supply passage 64 is connected to the passage 52. In FIGS. 1 to 7, 71 is a pin inserted into a through hole 72 formed in the primary chip 43, a pin hole 73 formed in the secondary chip 44 and a pin hole 74 formed in the supply block 61, This pin 71 has a nozzle tip 42 and a supply block 61.
Prevent relative rotation with. Again in FIG. 1, a seal rod 77 having a supply passage 76 formed therein is housed in the nozzle body 30 on the rear side of the supply block 61. A metering valve 78 that controls the flow rate of the inflowing fuel is housed. Reference numeral 79 is a spring interposed between the port block 28 and the seal rod 77. The spring 79 biases the seal rod 77 toward the tip, and the seal rod 77, the supply block 61, and the supply block 61. And the primary chip 43
Further, the primary tip 43 and the secondary tip 44 are brought into contact with each other to prevent fuel leakage from between them. The fuel flowing from the fuel passage 29 into the spring chamber 80 in which the spring 79 is installed is distributed and supplied to the primary supply passage 62 and the secondary supply passage 64 via the supply passage 76. The fuel passage 29, the primary and secondary supply passages 62 and 64, the supply passage 76, and the spring chamber 80 described above as a whole are the primary and secondary fuel injection ports 47 and 51.
Further, a supply passage 81 for supplying fuel through the swirl passages 46, 50 and the passage 52 is formed. Reference numeral 82 is a heat insulating material interposed between the support 24 and the nozzle case 25, and this heat insulating material 82 has a flange portion 83 located between the flange portions 22 and 26. The flange portion 83, the flange portions 22 and 26, and the port block 28 are fastened together by a plurality of bolts 84, so that the support 24, the nozzle case 25, the port block 28, and the heat insulating material 82 are connected to each other. Further, the heat insulating material 82 has a cylindrical portion 85 arranged while maintaining a slight gap between the cylindrical portions 23 and 27, and the cylindrical portion 85 includes the primary and secondary chips 43 and 44 and the supply passage 81. Surrounded. As a result, the fuel flowing in the primary and secondary chips 43 and 44 and the supply passage 81 is shielded from the ambient heat and is not adversely affected by carbonization or the like. 91 is a cylindrical air passage formed between the tip of the support 24 and the tip of the heat insulating material 82. As a result, the heat insulating material 82 is inside the air passage 91 and the air passage of the nozzle body 30. The part surrounded by 91 will be enclosed. Reference numeral 92 is an inlet opening as an air inlet in the air passage 91 and as a means for imparting a circumferential turning force to the air. As shown in FIGS. At the same time, it extends substantially parallel to the tangent to the cylindrical portion 23. As a result, the high-temperature air supplied to the air passage 91 in the state where the swirling force is applied moves spirally toward the tip inside the air passage 91, and the primary and secondary fuel injection ports 47, 51 Is ejected from the outlet opening 93 of the air passage 91 provided in the periphery of the chamber to the combustion chamber 48 while swirling in the circumferential direction. The metering valve 78 described above includes a ball-shaped valve body 101 that can be seated on the edge of the port 100 provided on the seal rod 77, and a receiver that is slidably supported in the seal rod 77 and receives the valve body 101. 102 and the supply block
Collar 103 that is in contact with 61, collar 103 and receiving body 102
The valve body 101 is interposed between the receiving body 102 and the port
And a setting spring 104 that urges toward 100. Then, slits 105 and 106 as fuel passages are provided on the peripheral surfaces of the receiving body 102 and the collar 103.

Next, the operation of the embodiment of the present invention will be described.

During operation of the gas turbine engine, the primary and secondary fuels are supplied to the primary and secondary swirl chambers through the supply passage 81 and the swirling passages 46 and 50.
45, 49, and swirl in the primary and secondary swirl chambers 45, 49, and also the primary and secondary fuel injection ports 47, 51.
Is injected into the combustion chamber 48 from a predetermined injection form. On the other hand, air is supplied from the inlet opening 92 into the air passage 91, but since the inlet opening 92 is substantially parallel to the tangent to the cylindrical portion 23, a swirling force in the circumferential direction is given to the air, As a result, the air moves toward the outlet opening 93 while spirally swirling in the air passage 91. Next, air is jetted into the combustion chamber 48 from the outlet opening 93 of the air passage 91 provided around the primary and secondary fuel injection ports 47 and 51. At this time, the air has a swirling force in the circumferential direction. Is given,
As shown in FIG. 1, the ejection form is an umbrella shape that surrounds the injected fuel immediately after the injection without cross-collision.
As a result, the air after being ejected has the primary and secondary fuel injection ports 47, 51.
It plays the role of an umbrella-shaped air curtain that isolates the
This prevents the injected fuel floating in the fuel chamber 48 from approaching the primary and secondary fuel injection ports 47, 51. This air also supplies hot oxygen to the combustion chamber 48 in order to operate the gas turbine engine with high efficiency.
When the temperature of the air is high as described above, the fuel flowing in the supply passage 81, the primary and secondary chips 43 and 44 may be heated, and a part thereof may be carbonized. However, in this embodiment, since the heat insulating material 82 is provided on the nozzle body 30 in the portion surrounding the supply passage 81, the primary and secondary chips 43, 44, the fuel is protected from the air and the high temperature of the combustion chamber 48. It

In addition, in the above-described embodiment, the inlet opening 92 is formed in the cylindrical portion 23.
By making them substantially parallel to the tangent line to, the circumferential swirling force is imparted to the air.However, in the present invention, the inlet opening 92 extends substantially parallel to the normal to the cylindrical portion 23. , Inside the air passage 91, for example the support 24
A fin for guiding air may be provided on the inner circumference of the cylindrical portion 23 or on the outer circumference of the cylindrical portion 85 of the heat insulating member 82, and the fin may be used to impart a turning force in the circumferential direction to the air.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is possible to prevent the floating injection fuel from approaching the fuel injection port of the injection nozzle, so that clogging occurs even after long-term use. There is no such thing.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a fuel injection nozzle for carrying out the present invention, FIG. 2 is a plan view of a primary tip, FIG. 3 is a sectional view taken along the line I--I of FIG. 4 is a plan view of the secondary chip, FIG. 5 is a sectional view taken along the line II-II in FIG. 4, FIG. 6 is a bottom view of the supply block, and FIG. 7 is a sectional view taken along the line III-III in FIG. FIG. 8 is a sectional view taken along the line IV-IV in FIG. 1, and FIG. 9 is a sectional view showing a conventional fuel injection nozzle. 30 ... Nozzle body, 47, 51 ... Fuel injection port 48 ... Combustion chamber, 91 ... Air passage 92 ... Swirling force applying means, 93 ... Exit opening

Claims (1)

[Claims] Claim: What is claimed is: 1. Immediately after injection from the fuel injection port, by giving a swirling force in the circumferential direction to the air ejected into the combustion chamber from the outlet opening of the air passage provided around the fuel injection port. A fuel injection method for a gas turbine engine, characterized in that an umbrella-shaped air curtain is formed around the fuel.