JPH06241455A - Fuel injection valve - Google Patents

Abstract

PURPOSE:To provide a fuel injection valve in which an increase in an air-fuel ratio is suppressed at the time of a low load of an engine and generation of carbon, smoke due to a decrease in the air-fuel ratio can be prevented at the time of a high load of the engine. CONSTITUTION:A fuel injection valve body 2 is mounted at an end of a gas turbine burner 1. The body 2 is formed with a fuel tube 5 for supplying fuel and a finely pulverized air channel for finely pulverizing the fuel and feeding it into the burner 1. A variable valve 3 is energized to be axially displaceably by a spring 4 in the body 2. An upper part of the valve 3 is formed in a piston structure, and an outer pressure P1 of the burner 1 is guided to its upper surface. The valve 3 is displaced by a pressure difference between a pressure P2 in the burner to be applied to its lower surface and the pressure P1 outside the burner 1 to so alter the channel as to reduce it in the case of a low load of small difference and to increase it in the case of a high load of large difference. Thus, an air-fuel ratio can be held at a preferable value corresponding to the load.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air flow atomizing fuel injection valve applied to a gas turbine or the like.

[0002]

2. Description of the Related Art A gas turbine has an overall structure as shown in FIG. 2, and in the combustion chamber portion A, fuel atomized by an air flow from a fuel injection valve at a portion indicated by B in FIG. The fuel gas is injected into the air flow indicated by and mixed with air to burn, and the combustion gas operates the gas turbine engine. The conventional air stream atomized fuel injection valve has a structure as shown in FIG. 4, and there is no variable mechanism in the flow channel of the air stream atomized fuel.
The passage area of atomized air is constant.

Combustion in a gas turbine engine is illustrated in FIG.
In the primary combustion region in the combustor body 1 as shown in Fig. 5, the fuel sent from the fuel pipe 5 and atomized by atomized air is mixed with air and burned, and then secondary air and diluted air are added. Mix. The air-fuel mixture ratio (air-fuel ratio) in the primary combustion region is large when the engine has a low load output when the airflow atomizing fuel injection valve body 2 which is not a conventional variable type is used. As a result (because the air-fuel ratio becomes large), blowout easily occurs, and when the load is high, the air ratio becomes small (because the air-fuel ratio becomes small), which causes problems such as generation of carbon and smoke.

[0004]

DISCLOSURE OF THE INVENTION The present invention suppresses the occurrence of blowout by increasing the air-fuel ratio when the engine is under a low load, and reduces the air-fuel ratio when the engine is under a high load, which causes carbon and smoke. It is an object to provide a fuel injection valve which is prevented. Still another object of the present invention is to provide a fuel injection valve capable of exhibiting the above-mentioned performance with a simple structure.

[0005]

In order to solve the above problems in a fuel injection valve having a structure in which fuel is mixed with atomized air and injected into a combustion region, the present invention is displaceable in a channel of atomized air. And a variable valve that changes the area of the flow passage by its displacement, and the variable valve employs a fuel injection valve configured to be displaced according to the pressure difference between the inside and the outside of the combustor. .

[0006]

According to the present invention, the variable valve provided inside the fuel injection valve is configured to be displaced according to the pressure difference between the inside and outside of the combustor, so that the pressure difference between the inside and outside of the combustor is small. In the low load state, the atomized air passage area is correspondingly reduced to reduce the air-fuel ratio in the primary air mixing region.
Further, in a high load state, the pressure difference between the inside and outside of the combustor increases, and accordingly, the variable valve is displaced so that the atomized air passage area increases, and the air-fuel ratio in the primary air mixing region can be increased. it can.

In this manner, when the engine has a low load output, the air-fuel ratio becomes large and blowout occurs, and when the engine has a high load output, the air-fuel ratio becomes small and carbon and smoke are generated. Absent.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fuel injection valve according to the present invention will be specifically described below based on the embodiment shown in FIG. In FIG. 1, the same parts as those in the fuel injection valve shown in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted. A variable valve 3 which is biased upward by a spring 4 and whose vertical position is variable is provided inside a fuel injection valve body 2 attached to the upper part of the combustor 1. The variable valve 3 has a piston structure that moves up and down according to the pressure difference between the pressure P _{1 on the} outer circumference of the combustor and the internal pressure P _{2 of the} combustor, and the area of the atomized air passage changes due to the up and down movement.

That is, the variable valve 3 receives the pressure P ₂ inside the combustor 1 at its lower surface and the pressure P ₁ outside the combustor 1 at its upper piston surface. Of the atomizing air passage formed between the lower end of the fuel injection main body 2 and the variable valve 3 corresponding to the difference between the internal pressure and the external pressure of the combustor 1. Change to.

Therefore, since the differential pressure between P ₁ and P ₂ is small in the low load state, the variable valve 3 rises and the atomized air passage area decreases, and conversely in the high load state, P ₁ and P ₂ The variable valve 3 is lowered because the differential pressure is increased, and the atomized air passage area is increased.

Although the present invention has been specifically described based on the illustrated embodiments, the present invention is not limited to these embodiments, and the shape and structure thereof are within the scope of the present invention shown in the claims. It goes without saying that various changes may be added to the. For example, in the above embodiment, the variable valve 3 is directly displaced by the inner and outer pressures P ₁ and P ₂ of the combustor 1, but the inner and outer pressures of the combustor 1 are detected and the difference is detected. The variable valve 3 may be displaced via another transmission medium or mechanism.

[0012]

As described above in detail, in the fuel injection valve according to the present invention, it is arranged so as to be displaceable in the passage of the atomized air, and the displacement allows the area of the passage to be changed. Since the variable valve is configured to be displaced according to the pressure difference between the inside and the outside of the combustor, in the low load state in which the pressure difference is small, the variable valve is correspondingly Since the flow path is made small, the air-fuel ratio can be made small and blowout can be prevented.

[0013] In the high-load state where the pressure difference increases, so the corresponding flow path of the atomizing air which is large, it is possible to increase the air-fuel ratio, an increase in the carbon generation and NO _X Can be prevented. in this way,
According to the fuel injection valve of the present invention, the atomized air amount is adjusted in a reliable manner in response to fluctuations in combustion load.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a gas turbine combustor including a fuel injection valve according to an embodiment of the present invention.

FIG. 2 is a sectional view showing the overall configuration of a gas turbine.

FIG. 3 is an enlarged cross-sectional view of a combustion chamber portion in the gas turbine shown in FIG.

FIG. 4 is a cross-sectional view of a gas turbine combustor including a conventional fuel injection valve.

[Explanation of symbols]

 1 Combustor body 2 Fuel injection valve body 3 Variable valve 4 Spring 5 Fuel pipe

Claims (1)

[Claims] 1. A fuel injection valve that mixes fuel with atomized air and injects the atomized air into a combustor. The fuel injector is displaceably disposed in a channel of the atomized air, and the displacement causes an area of the channel. The variable fuel injection valve is characterized in that the variable valve is configured to be displaced according to a pressure difference between the inside and the outside of the combustor.