Gas turbine

Abstract

The invention provides a gas turbine, in which compressed air that is compressed by a compressor (11) is mixed with fuel in a combustor (12), the mixture is burned to produce combustion gas, and the combustion gas is provided to a turbine (13) to produce rotative power, includes: a pressurizing unit (41) that pressurizes some of the compressed air that is compressed by the compressor (11); a combustor cooling unit (42) that cools the combustor (12) with the compressed air that is pressurized by the pressurizing unit (41); and a compressed air circulation line (46) that provides the compressed air to the casing of the combustor (12). In the gas turbine, the combustor can be cooled by minimizing pressure loss of the compressed air, and degradation of the power efficiency can be prevented.

Description

technical field [0001] The present invention relates to a gas turbine that supplies fuel to compressed compressed air to combust it, and supplies the generated combustion gas to a turbine to obtain rotational power. Background technique [0002] A general gas turbine is composed of a compressor, a combustor, and a turbine. The air taken in from the air inlet is compressed by the compressor to become high-temperature and high-pressure compressed air. In the combustor, fuel is supplied to the compressed air and combusted. The high-temperature, high-pressure combustion gas drives a gas turbine, which in turn drives an electric generator connected to the turbine. [0003] In such a gas turbine, when the combustion temperature of the combustor becomes high, nitrogen oxides (NOx) in the exhaust gas increase, so a cooling device is provided in the combustor. Conventional cooling devices for combustors include steam cooling methods, air cooling methods, recovery air cooling methods...

AI Technical Summary

Problems solved by technology

In the cooling device of the steam cooling method, since the burner is cooled by the steam generated by the exhaust heat recovery boiler, incidental equipment such as steam piping for circulating the steam between the gas turbine and the exhaust heat recovery boiler is required, resulting in a structural increase in size and complexity

In addition, in order to cool the gas turbine, it is necessary to start the exhaust heat recovery boiler, which complicates the operation control, and at this time, since the exhaust heat recovery boiler needs to be preheated, the start-up time becomes longer

Furthermore, since the combustor is cooled by steam, there is a problem that the gas turbine loses heat, resulting in low equipment efficiency

[0009] In an air-cooled cooling device, since the combustor is cooled by using a part of the compressed air compressed by the compressor, there is a problem that the combustion air decreases, the combustion temperature in the combustor rises, and the NOx in the exhaust gas increases.

In addition, in an ultra-high temperature gas turbine, since the temperature of the cylinder chamber rises to a high temperature, the cooling capacity of the cooling device of the air cooling method is low, and it is difficult to achieve cooling.

Furthermore, in the cooling device of the recovery air cooling method, although the combustor is cooled by the compressed air compressed by the compressor, the cooled compressed air is supplied to the combustor, and the low nitrogen can be achieved by ensuring the combustion air. However, since the compressed air is recovered after cooling the combustor wall, there is a problem that the pressure loss in the combustor is large and the efficiency of the turbine is low

In addition, since the flow channel sleeve needs to be provided on the outer peripheral side of the inner cylinder of the combustor, the structure becomes complicated due to the increase of structural parts.

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