JPS6060221A - Method of and apparatus for supplying combustion air in gas-turbine plant - Google Patents

Abstract

PURPOSE:To enable to obtain an output equal to the rated value throughout the year, by providing an auxiliary-air supply source on the upstream side of a combustor, and supplying correcing air to the combustor at the rate detected through comparison of the designed ambient temperature and the actual ambient temperature. CONSTITUTION:An auxiliary-air supply source 15 is provided on the upstream side of a combustor 5, and the temperature of air drawn into a compressor 3 is detected by a detector 26. The quantity of correcting air is calculated by a comparing means 28 through comparison between the design ambient temperature and the actual ambient temerature, and the correcting air is supplied to the combustor 5 by controlling an air control valve 29. With such an arrangement, it is enabled to obtain an output equal to the rated value throughout the year.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention can prevent a decrease in turbine output during the summer or during the day by adding a small-capacity air supply facility, and can improve the annual utilization of the plant. This is a gas turbine plan installed for driving equipment and power generation in general industry]. The present invention relates to a combustion air supply method and apparatus that can be widely used in the field.

(Prior art) A conventional gas turbine plant is shown in Fig. 1.
The fuel compressor 2 and the fuel compressor 2 are axially coupled to the gas turbine 4 , and the air compressor 3 is coupled to the gas turbine 4 via a gear 7 . On the other hand, air compressor 3 and combustor 5. Fuel compressor 2 and combustor 5. The combustor 5 and the gas turbine 4 and the gas turbine 4 and the exhaust gas boiler 6 are connected by respective piping.

In this configuration, air 9 at atmospheric pressure is suctioned and pressurized by the air compressor 3 and supplied to the combustor 5 through a high-pressure air pipe 11, while fuel 8 is pressurized by the fuel compressor 2 and pressurized to the high-pressure fuel pipe 11. It is then supplied to the combustor 5, where it is combusted to generate high-temperature, high-pressure combustion gas.

This combustion gas is introduced into the gas turbine 4 through the high-pressure combustion gas pipe 12, and drives the gas turbine 4 to rotate. Combustion gas emitted from the gas turbine 4 is led to the exhaust gas boiler 6 through the gas turbine exhaust gas piping 13, where it exchanges heat with liquid or gas and is discharged into the atmosphere.

In such a Kasturbine plant, a generator, a fuel compressor, a combustor, a gas turbine, and a boiler are conventionally used in areas where the winter and summer temperatures are, for example, 0°C and 30°C, as shown in Figure 2. The installed capacity is determined at the minimum temperature of 0℃ (hereinafter referred to as the design atmospheric temperature), and the 5 air compressors are set at the intermediate temperature (standard output point in Figure 2) of 15℃.
It was designed with.

Incidentally, the actual amount of air supplied to the air compressor is reduced by the current atmospheric temperature compared to the design atmospheric temperature that determined the installed capacity.

On the other hand, if the fuel supply amount is kept constant, the combustion gas temperature will gradually rise and exceed the allowable temperature at the gas turbine inlet, so the fuel supply amount must be reduced in line with the actual air amount. No.

This relationship is shown in the dash-dotted lines A to C in Figure 2.
As a result, the power generation output becomes the solid line 4~.

In summer (atmospheric temperature 30°C), the output decreases by about 20 times compared to the installed capacity.

In other words, in a conventional gas turbine plant, even if the air compressor is operated at 100% output as designed.

Due to temperature changes, the annual utilization rate of the plant decreases.

It had the disadvantage of being uneconomical to operate.

(Object of the Invention) An object of the present invention is to provide a method for supplying combustion air to a gas turbine plant, which allows a rated output to be obtained throughout the year.

(Structure and operation of the invention) The present invention provides an auxiliary air supply source to a gas turbine plant consisting of a generator, an air compressor, a fuel compressor, a combustor, a gas turbine, a boiler, and piping connecting them. The corrected air amount is calculated based on the difference between the design atmospheric temperature, which determines the installed capacity, and the current atmospheric temperature, and the corrected air amount is supplied to the combustor from the auxiliary air supply source, ensuring that the combustor maintains the rated value throughout the year. This is a method for supplying combustion air to a Kasturbine plant that allows a power generation output of 1.

In other words, the apparent intake air amount of the air compressor is assumed to be so, and the difference between the design atmospheric temperature and the current atmospheric temperature is 41°C (T), which is supplied from the auxiliary air source to the combustor to generate the rated power output. That's what you're trying to get.

(Example〕 Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 shows an embodiment of the present invention in which temperature differences are detected and compared, and the amount of air is increased or decreased to blow air into the combustor.

The temperature of the intake air to the air compressor 3 is detected by the temperature detector 26, and its value is inputted from the signal line 30 to the comparison calculation control device 28. The comparison arithmetic and control device calculates the corrected air amount from the difference between the design atmospheric temperature and the current atmospheric temperature, adjusts the opening degree of the air control valve 29, and adjusts the amount of air from the auxiliary air compressor 15 to the combustor 5 according to the temperature difference. Supply correction air volume. In this case, the combustion gas temperature on the inlet side of the gas turbine 4 is detected by the temperature detector 27.

Further, the opening degree of the air control valve 29 is adjusted so that the gas turbine inlet side temperature is below the permissible temperature.2 Figures 4 to 6 show embodiments of the present invention and show the main system of the auxiliary air supply source. The comparison arithmetic control device, etc. are omitted.

FIG. 4 shows an auxiliary air compressor 15 installed upstream of the combustor 5 in the conventional gas turbine plant shown in FIG.
It is installed via the shaft of the gas turbine 4, the gear 7, and the clutch 16, and supplies the combustor 5 with a corrected air amount in accordance with changes in temperature.

In FIG. 5, an auxiliary air compressor 17 and an electric motor 18 are provided at a location different from the shaft system shown in FIG. 4, and supply a corrected air amount to the combustor 5 in accordance with changes in temperature.

The auxiliary air compressor shown in FIGS. 4 and 5 is preferably an air compressor with good load efficiency from high load to low load 1.

Figure 6 shows an air booster 19 that receives excess air from the air pipe 14 at medium and low pressure (8 to 2 Kg/ctpr) and boosts the pressure to the high pressure (10 to 9/c, 1 or more) required for the gas turbine plant. The auxiliary air supply source is provided with piping that connects the blast furnace 20 and the blast furnace blower η, piping that connects the oxygen generator 21 and the raw material air compressor 24, and connects the miscellaneous air use factory 22 and the process air compressor 5. The medium and low pressure air piping 14 such as piping is used as an air main pipe.

(Effects of the Invention) By implementing the method of the present invention, the annual utilization rate of the gas turbine plant is improved by approximately 8%.In other words, in Figure 2, the power generation output decrease curve E at the temperature and the annual temperature change cumulative The value of the 8th factor from the curve is 1, and the trial calculation for an IOMW power plant is shown as follows: 10MW x o, o 8 (8% increase x 8,400 hours/year x 20 yen 4gW, or approximately 1.4 billion yen/year in benefits) .

■ In particular, in the case of by-product gas from steel plants, the amount of gas generated is approximately constant and there is no seasonal change in flow rate like in the atmosphere, so fuel supply and demand can be balanced and gas dissipation losses in the summer can be prevented.

[Brief explanation of the drawing]

Figure 1 shows a conventional gas turbine plant. . FIG. 2 shows the relationship between atmospheric temperature and gas turbine characteristics in a conventional gas turbine plant. FIG. 3 shows an example of a method of increasing or decreasing the actual amount of air to the combustor according to the present invention. FIG. 4 shows an example of an installation of an auxiliary air compressor. FIG. 5 shows another example of installing an auxiliary air compressor. FIG. 6 shows an example of an auxiliary air supply device in which a medium-low pressure air pipe and an air booster are paired. 1... Generator, 2... Fuel compressor, 3... Air compressor, 4... Gas turbine, 5... Combustor, 6...
・Exhaust gas boiler, 7... Gear, 8... Fuel, 9
...Air at atmospheric pressure. 10... High pressure fuel pipe, 11... High pressure air pipe, 12... High pressure fuel gas pipe, 13... Gas turbine exhaust gas pipe, 14... Medium and low pressure air pipe, 15
...Auxiliary air compressor, 1G/9. Clutch, 17...
・Separately installed auxiliary air compressor, 18...Electric motor, 19...
・Air booster, 20... Blast furnace, 21... Oxygen generator, 22... Factory using miscellaneous air, 23... Blast furnace blower 524... Raw material air compressor, Z5... For process air compressor. 26... Atmospheric temperature detector, 27... Turbine inlet combustion gas temperature detector, 28... Comparison calculation control device, 29
...Air flow control valve, 30...Signal wiring. Patent applicant Representative patent attorney Tomoyuki Yafuki (and 1 other person)

Claims (1)

[Claims] 1° Generator, air compressor, fuel compressor, combustor. An auxiliary air supply source is installed upstream of the combustor in a gas turbine plant consisting of a gas turbine, boiler, and piping that connects them, and the amount of air is corrected based on the difference between the design atmospheric temperature that determined the installed capacity and the current atmospheric temperature. A combustion air supply method for a gas turbine plant, characterized in that the correction air amount is supplied from the auxiliary air supply source to a combustor. 2. In a gas turbine plant consisting of an air compressor, a fuel compressor, a combustor, a gas turbine, and piping connecting them, an auxiliary compressed air source connected to the piping connecting the air compressor and the combustor; A temperature detector that detects the inlet air temperature of the air compressor, and a comparison calculation control that calculates a corrected air amount by comparing the signal from the temperature sensor with the design atmospheric temperature that determined the installed capacity, and outputs the corrected air amount. 1. A combustion air supply system for a gas turbine plant, comprising: a combustion air supply system; and an air flow rate control valve arranged on the outlet side of the auxiliary compressed air source and controlled by an output signal from the comparison arithmetic and control unit.