JPH0953464A - Gas turbine combustion equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the combustibility of methane which is main fuel and enable further low temperature combustion by the conventional burner so as to reduce NOx by pre-mixing gas flue formed by mixing at least one kind among propane, butane and ethane with fuel taking methane as the main component with air for fuel and burning the same. SOLUTION: Propane, butane and ethane 7 are added separately or as a mixture thereof to methane 6 which is fuel for a gas turbine and mixed by a mixer 8. The mixture is supplied to a combustor 3 and pre-mixed with a large quantity f high pressure air 1 compressed by a compressor 2. Thus, combustion gas burnt at a further lower temperature than that in the case of burning methane 6 separately is supplied to a turbine 4 and discharged as exhaust gas 5. Thus, NOx generation can be restrained without damaging combustion stability.

Description

Detailed Description of the Invention

[0001]

The present invention relates to relates to low NO _x technique applied to a combustor of a gas turbine.

[0002]

2. Description of the Related Art FIG. 2 is a system diagram showing an example of a turbine adopting a conventional low NO _x combustion technology. The air (1) is compressed to a high pressure by the compressor (2) and premixed with methane (6), which is the main component of LNG, in the combustor (3) to generate NO.
_In order to suppress the emission of _x , it is burned at a combustion temperature as low as possible, and high temperature gas is supplied to the turbine (4).

[0003]

When the fuel (6) containing methane as a main component and the air (1) compressed to a high pressure are premixed and burned in the combustor (3), the fuel and the air are mixed as much as possible. To reduce the ratio and lower the temperature of the combustion area is
It is necessary to suppress the generation of O _x . However, the mixture of methane and air has deteriorated combustibility at a certain fuel / air ratio or less, and limits the suppression of NO _x .

It is a problem to be solved by the present invention that the limit of NO _x reduction should be further lowered without major modification of the combustion apparatus, especially the burner section of the combustor.

[0005]

In order to solve the above-mentioned conventional problems, the present inventor has proposed a gas fuel prepared by mixing at least one of propane, butane and ethane with a fuel containing methane as a main component. The present invention proposes a gas turbine combustor characterized in that it is premixed with combustion air for combustion.

In the present invention, the lower limit of the combustion stability of the fuel / air ratio of the methane / air premixture can be significantly improved by mixing propane, butane, ethane, etc. By lowering the lower limit of the / air ratio, it is possible to lower the combustion temperature and suppress the generation of NO _x .

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a system diagram showing an embodiment of the present invention. Propane, butane, ethane and the like (7) are added alone or as a mixture to methane (6) which is the fuel of the gas turbine and mixed in a mixer (8). This is supplied to a combustor (3) and premixed with a large amount of high-pressure air (1) compressed by a compressor (2) to produce methane (6).
Combustion gas burned at a temperature lower than that of a single gas is supplied to the turbine (4) and discharged as exhaust gas (5). Thereby, NO _x production can be suppressed without impairing combustion stability.

[0008]

INDUSTRIAL APPLICABILITY According to the present invention, the combustibility of methane, which is the main fuel, is improved by the hydrocarbons other than methane that can be easily supplied, and the combustor, particularly the burner part, is not remodeled conventionally. This burner enables combustion at a lower temperature and reduces NO _x .

[Brief description of drawings]

FIG. 1 is a system diagram of a gas turbine according to an embodiment of the present invention.

FIG. 2 is a system diagram showing an example of a gas turbine adopting a conventional low NO _x combustion technology.

[Explanation of symbols]

 (1) Air (2) Compressor (3) Combustor (4) Turbine (5) Exhaust gas (6) Methane (7) Hydrocarbons other than methane (8) Mixer

Claims (1)

[Claims] 1. A fuel containing methane as a main component, propane,
A gas turbine combustion apparatus, characterized in that a gaseous fuel prepared by mixing at least one of butane and ethane and combustion air are mixed in advance and burned.