JPS58162730A - Gas turbine apparatus - Google Patents

Abstract

PURPOSE:To achieve a higher thermal efficiency and an increase in the specific output by enabling reheating even when the quantity of oxygen contained in combustion gas is limited. CONSTITUTION:An air compressed with a compressor 1 is introduced to a combustor 2 to generate a high humidity / high pressure combustion gas, which is introduced to a high pressure turbine 3 and then to a reheater 4. At this point, a compressed air of a specified pessure extracted at the intermediate stage of the compressor 1 is introduced as combustion air. The combustion gas raised in the temperature is introduced to a low pressure turbine 5 and exhaust introduced to an exhaust heat boiler 10 whose heat is fed to a steam cycle. Steam generated with an exhaust heat recovery boiler 10 is introduced to a steam turbine 11 and condensed with a condenser 12 to water which is introduced to the exhaust heat boiler 10 with a water supply pump 13. The load with a steam turbine 11 is driven.

Description

[Detailed description of the invention] The present invention relates to a gas turbine device.

In order to improve thermal efficiency in gas turbines and turbines, it is necessary to increase the maximum cycle temperature, that is, the turbine inlet temperature. However, if the turbine inlet temperature is limited by the heat resistance of the turbine and the turbine blades have a low allowable temperature limit, the gas temperature is lowered by mixing dilution air into the combustion gas in the combustor. In addition, when the M temperature resistance of the turbine blades is high, 1i, the combustion gas is not diluted, combustion in the combustor is performed near the stoichiometric mixture ratio, and high-temperature combustion gas is guided to the turbine. Reheating is performed in order to combine adiabatic expansion with isothermal expansion in the turbine to increase specific output as well as thermal efficiency. In an internal combustion gas turbine, fuel is supplied to a reheater installed between multiple stages of the turbine, and the unburned oxygen contained in the combustion residue is expanded to a predetermined pressure in the high-pressure stage of the turbine and the temperature has decreased. The fuel is combusted using the gas, the gas temperature is raised again, and the gas is supplied to the subsequent turbine.
When performing this reheating, the temperature of the gas turbine exhaust increases, so the gas turbine exhaust is guided to the exhaust heat recovery boiler 9.
Significant improvements in thermal efficiency can be achieved by configuring a combined gas/steam cycle in which the generated steam drives a steam turbine.

However, as mentioned above, as the maximum cycle temperature of the cast turbine, that is, the inlet temperature of the turbine high pressure stage, increases, the combustion in the combustor approaches the stoichiometric mixing ratio, so that the unburned oxygen contained in the combustion gas increases. Contains less berries. When the oxygen content in the combustion gas is low,
The soot burning of the fuel for reheating becomes unstable, furthermore, combustion becomes impossible, and therefore, reheating becomes impossible. In addition, the greater the number of reheats, the higher the thermal efficiency and the greater the specific output. However, even if the combustion gas exiting the combustor contains a large amount of unfurnished oxygen, reheating reduces the amount of oxygen consumed. This makes it impossible to perform multi-stage reheating.

The present invention has been made in view of the above circumstances, and its purpose is to improve thermal efficiency and increase specific output by making it possible to perform reheating even when there is little oxygen contained in the combustion gas. It is an object of the present invention to provide a gas turbine device that can be expanded.

An embodiment of the present invention will be described below based on the drawings.

In the first embodiment of the present invention, as shown in FIG. 1, 1 is a compressor, 2 is a combustor, and 3 is a high-pressure turbine.

4 is a reheater, 5 is a low-pressure turbine, 6 is a load, and 7 is a flow path for guiding compressed air of a predetermined pressure extracted at an intermediate stage of the compressor 1 to the reheater 4. The air compressed by the compressor 1 is guided to the combustor 2, where the fuel supplied through the pipe line 8 indicated by the broken line is combusted to generate high-temperature and high-pressure combustion gas. The combustion gas is guided to the high pressure turbine 3, where it performs expansion work.

Combustion gas whose pressure has decreased to a predetermined value and whose temperature has decreased due to adiabatic expansion in the high-pressure turbine 3 is guided to a reheater 4.

The temperature of the combustion gas guided to the high pressure turbine 3 is increased,
Therefore, combustion in the combustor 2 takes place near the stoichiometric mixture ratio, and the amount of oxygen contained in the combustion gas led to the reheater 4 is small.

Further, compressed air at a predetermined pressure extracted at an intermediate stage of the compressor 1 is guided to the reheater 4 as combustion air through a flow path 7. In the reheater 4, the combustion air is used to combust the fuel supplied through the pipe line 9 indicated by the broken line, and the temperature of the combustion gas is increased.

The combustion gas whose temperature has been raised in the reheater 4 is guided to the low pressure turbine 5 and performs expansion work.

A compressor 1 and a load 6 are driven by a high pressure turbine 3 and a low pressure turbine 5. Furthermore, the exhaust gas exiting the low-pressure turbine 5 is still at a high temperature, and is led to the exhaust heat recovery boiler 10 to feed the steam cycle. In the steam cycle, the steam generated in the exhaust heat recovery boiler IO is led to the steam turbine +1 (1.

After performing the expansion work, the condensate is condensed in the condenser 12, and the condensate is led to the exhaust heat recovery boiler 10 by the water supply pump 13, where it is heated by the gas turbine exhaust gas, evaporated, and superheated. An embodiment of the shaft 2 of the present invention in which the load 14 is driven by the steam turbine 11 is shown in FIG.
1 tt compressor, 22 a combustor, 23 a high pressure turbine,
24 is a high pressure reheater, and 25 is an intermediate pressure turbine.

26 is a low pressure reheater, and 27 is a low pressure turbine.

Reference numeral 28 denotes a flow path for guiding compressed air of a predetermined pressure extracted at an intermediate stage of the compressor 21 to the low-pressure reheater 26.

Air compressed by the compressor 21 is guided to the combustor 22, where the fuel supplied through the pipe line 29 shown by the broken line is combusted to generate high-temperature, high-pressure combustion gas.

The combustion gas is guided to the pressure turbine 23, where it performs expansion work. ＾pressure turbine 23
The combustion residue whose pressure has decreased to a predetermined value and whose temperature has decreased due to the adiabatic expansion in the combustion chamber 2 is led to the high-pressure reheater 24.

Dilution air is mixed into the combustion gas generated in the combustor 22, and the temperature of the combustion gas guided to the high pressure turbine 23 is lower than the temperature of the combustion gas guided to the high pressure turbine 8 of the first embodiment. The furnace gas leaving the single pressure turbine 23 contains a large amount of oxygen. High pressure turbine 2
The combustion gas exiting from the combustion gas 3 is led to a high-pressure reheater 24, where the fuel supplied through the pipe 30 is combusted using the oxygen contained in the combustion gas.

The combustion gas whose temperature has been increased in the high pressure reheater 24 is
Combustion gas whose pressure has been reduced to a predetermined value and whose temperature has been reduced by adiabatic expansion in the intermediate pressure turbine 25 is guided to the intermediate pressure turbine 25 to perform expansion work, and is guided to the low pressure reheater 26 .

Oxygen in the combustion gas is consumed by combustion in the high-pressure reheater 24, and the oxygen content in the combustion gas led to the low-pressure reheater 26 is low. Compressed air at a predetermined pressure, which is bled in the middle of the machine 21, is led through the channel 8 as the furnace firing air. In the low-pressure reheater 26, the -1 combustion air is used to combust the fuel supplied through the pipe line 31, increasing the temperature of the combustion residue.

In the low-pressure reheater 26, the soot scum with increased [[
High-pressure turbine 23 medium-pressure turbine 25° low-pressure turbine 27 guided by low-pressure turbine 27 to perform III tensioning
The compressor 21 and the load 6 are driven by. Further, the exhaust gas exiting the low pressure turbine 27 is guided to the exhaust heat recovery boiler 10 to supply heat to the steam cycle, and the operation of the steam cycle is the same as in the first embodiment.

In addition, in the above embodiment, the desired air extracted from the compressor is guided to the reheater as combustion air, but it is also possible to provide a compressor whose sole purpose is to supply compressed air to the reheater. In addition, compressed air is supplied to P4 from a source separate from the cast turbine. ! It is also possible to introduce it into a 1/2 vessel.

As explained above, since the gas turbine system according to the present invention is equipped with a reheater through which compressed air is introduced as combustion air, the maximum cycle temperature of the gas turbine, that is, from the combustor to the high pressure stage of the turbine, is restricted. Even when the temperature of the combustion gas is high and the amount of oxygen contained in the combustion gas is low.

Single or multiple reheats can be performed, thus increasing the efficiency and specific power of the gas turbine.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a first embodiment of the invention, and FIG. 2 is a system diagram showing a second embodiment of the invention. 1.21...Compressor, 2.22...Combustor, 3.23...
- High pressure turbine, 4... Reheater, 5.27... Low pressure turbine, 7.28... Channel, 24... High pressure reheater.

Claims (1)

[Claims] A gas turbine device comprising a reheater through which compressed air is guided as combustion air.