JP3778225B2 - Gas turbine power generator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas turbine power generator, and more particularly to a gas turbine power generator that performs intermediate cooling and steam injection.
[0002]
[Prior art]
In a power generator using a gas turbine, a steam-injected gas turbine cycle (STIG cycle or CHEN cycle) that improves performance by injecting water vapor into air or combustion gas, and an intercooler Intercooled and Steam-Injected Gas Turbine (ISTIG cycle) is known (eg “An Assessment of the Thermodynamic Performance of Mixed Gas-Steam Cycles: Part A-Intercooled and Steam”) -Injected Cycles ", Journal of Engineering for Gas Turbine, Vol. 117, July 1995).
[0003]
FIG. 3 is an example of a reburning type CHAT cycle using an intercooler, in which air A is compressed by compressors 1a, 1b, 1c, and 1d, contains moisture by saturator 2, and is preheated by exhaust heat recovery device 3. Then, the fuel F supplied to the combustors 4a and 4b and separately preheated fuel F is combusted to generate a high temperature gas E. The high temperature gas E rotates the high pressure turbine 5a and the low pressure turbine 5b to generate electric power, and further discharges. The heat recovery device 3 recovers the exhaust heat. In this cycle, the intercooler 6 is provided between the compressors 1b, 1c, and 1d, and a thermal efficiency of 54.7% is achieved when the inlet temperature of the low-pressure gas turbine is 1394 ° C. In addition, 9 is a generator in this figure.
[0004]
FIG. 4 is an example of the ISTIG cycle reported in the above-mentioned literature. As shown in FIG. 4 (A), this cycle is a combined cycle provided with a steam turbine 7 in addition to the intercooler 6, and air mixed with water vapor in the mixer 8 is supplied to the combustor 4 to improve thermal efficiency. It comes to improve. The other basic configuration is substantially the same as the CHAT cycle of FIG. 3 except that there is no saturator and low-pressure combustor. In this ISTIG cycle, as shown in FIG. 4B, a thermal efficiency of about 53% is achieved when the gas turbine inlet temperature is 1500 ° C.
[0005]
Further, FIG. 5 shows an example of a next generation combined cycle for performing intermediate cooling, and an intermediate cooler 6 and a steam turbine 7 are provided in the same manner as in FIG. 4, and both the gas turbine 5b and the steam turbine 7 generate electric power. ing. In addition to FIGS. 3 to 5, water may be directly injected into the compressed air without using an intercooler.
[0006]
[Problems to be solved by the invention]
The above-described CHAT cycle, ISTIG cycle, and next-generation combined cycle achieve high thermal efficiency (about 53% at a gas turbine inlet temperature of 1500 ° C.) as compared with existing gas turbine power generation devices. However, in these intermediate coolers, the compressed air is cooled by cooling water (make-up water or external cooling water), and the make-up water is used as jet steam to the turbine, and is discharged into the atmosphere after finishing the work in the turbine. This amount is normally about 10 to 15 wt% of the intake air amount, and if the outlet temperature of the low-pressure compressor is 100 ° C. or less, this amount can cool the air supplied to the combustor to about 40 to 50 ° C. it can. However, if the compression ratio of the low-pressure compressor is increased to improve the cycle efficiency, the outlet temperature becomes 150 ° C. or higher, and it is necessary to increase the amount of external cooling water and lower the outlet air temperature accordingly. In addition, the amount of heat loss increases. Further, if makeup water is used as it is, the outlet temperature becomes high and the effect of intermediate cooling cannot be obtained sufficiently. Furthermore, the means for directly injecting and injecting water can cool, but since steam is added, there is a problem that the driving power of the high-pressure compressor increases.
[0007]
The present invention has been developed to solve the above-described problems. That is, an object of the present invention is to provide a gas turbine power generator capable of intercooling a large amount of heat without increasing the amount of cooling water (amount of makeup water), thereby achieving higher thermal efficiency than before. There is.
[0008]
[Means for Solving the Problems]
According to the present invention, an intermediate cooler including a gas-liquid heat exchanger and a steam generator is provided between a plurality of compressors, and the gas-liquid heat exchanger and the steam generator are compressed air by a low-pressure side compressor. the steam generator is arranged to cool in the order of the gas-liquid heat exchanger, to preheat the cooling water (makeup water) in the gas-liquid heat exchanger and preheated by the gas-liquid heat exchanger wherein at least a portion of the coolant is evaporated in the steam generator, the generated steam is configured for supplying the turbine, the gas turbine power plant is provided, characterized in that.
[0009]
The present invention is characterized in that, in addition to sensible heat cooling with makeup water (cooling water), a part thereof is led to a steam generator to enhance the cooling effect on the air side and the generated steam is introduced into the turbine to increase the output. It is what.
That is, the intercooler is composed of a steam generator and a gas-liquid heat exchanger, the compressed air that has exited the low-pressure compressor is first introduced into the steam generator, and the compressed air that exits the steam generator is the gas-liquid heat exchanger Enters, is further cooled with makeup water, and enters the high pressure compressor. With this configuration, the amount that cannot be cooled by only sensible heat of a small amount of cooling water (makeup water) can be further cooled using the latent heat of water (evaporation heat).
[0010]
On the other hand, the supplied cooling water (make-up water) is preheated by the gas-liquid heat exchanger, and part of the make-up water leaving the gas-liquid heat exchanger is evaporated by the steam generator and introduced into the turbine. Power can be recovered from the steam generated by cooling the air, which can further improve the efficiency of the plant.
[0011]
According to a preferred embodiment of the present invention, a portion of the cooling water heated in the gas-liquid heat exchanger (makeup water) sent to the deaerator feed water heater as boiler feed water, the steam generated by the steam generator sending part in said deaerator feed water heater, thereby degassed by heating the boiler feed water to the saturation temperature, and supplies the remaining steam leaving the steam generator to the turbine. That is, by sending most of the cooling water (makeup water) heated by the gas-liquid heat exchanger to the degassing feed water heater, and further sending a part of the steam generated by the steam generator to the degassing feed water heater, The boiler feed water can be heated to the saturation temperature by this steam to degas the boiler feed water, and the steam generated by cooling the compressed air can be used not only for power recovery but also for heating the deaerator, Steam that has been necessary in the past can be saved and the efficiency of the plant can be further improved.
[0012]
The turbine for supplying steam is a gas turbine or a steam turbine. That is, the efficiency of a gas turbine power generation apparatus without a steam turbine can be increased by introducing the generated steam into the gas turbine to increase the output, or the combined cycle efficiency can be increased by supplying the steam turbine. You can also.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each figure, common portions are denoted by the same reference numerals, and redundant description is omitted.
FIG. 1 is a configuration diagram of a gas turbine power generator according to the present invention. In this figure, the gas turbine power generator 10 of the present invention includes an intermediate cooler 14 comprising a gas-liquid heat exchanger 12 and a steam generator 13 between a plurality of compressors (low pressure compressor 1a and high pressure compressor 1b). I have. As shown in this figure, the gas-liquid heat exchanger 12 and the steam generator 13 are arranged so as to be countercurrent to the flow of compressed air, and the compressed air generated by the low-pressure compressor 1a is used as the steam generator. 13. The gas-liquid heat exchanger 12 is cooled in this order, the cooling water is preheated by the gas-liquid heat exchanger 12, and then at least a part thereof is evaporated by the steam generator 13. The gas-liquid heat exchanger 12 and the steam generator 13 may be plate fin heat exchangers, but may be ordinary shell and tube heat exchangers.
[0014]
In FIG. 1, 15 is a dilator (deaeration feed water heater), 15a is a vent condenser, 16a and 16b are heat exchangers, 17a and 17b are preheated water supply lines, 18a and 18b are steam lines, and 19 is a stack (chimney). ). In this embodiment, a part of the cooling water (make-up water) heated by the gas-liquid heat exchanger 12 is sent to the degassing feed water heater 15 as boiler feed water via the feed water line 17 a, and steam generated by the steam generator 13 is sent. Is sent to the degassing feed water heater 15 through the steam line 18b, whereby the boiler feed water is heated to the saturation temperature and degassed, and the remaining steam from the steam generator 13 is sent to the steam line. The low pressure turbine 5b is supplied via 18a.
[0015]
As a result of trial calculation of the heat balance of the gas turbine power generation device 10 shown in FIG. 1, it was confirmed that when the high-pressure turbine inlet temperature is about 1500 ° C., a power generation output of 179 MW and a thermal efficiency of 55.3% can be achieved. That is, compared with the conventional gas turbine power generator shown in FIGS. 3 to 5, a high thermal efficiency of about 0.6 to 2% or more can be achieved at the same gas turbine inlet temperature 1500 ° C.
[0016]
In this case, of 145 tons of makeup water, 129 tons are sent to the degassing feed water heater 15 via the feed water line 17a, and 15 tons of the remaining are supplied to the low pressure turbine 5b via the steam line 18a. The remaining about 0.6 ton was supplied to the degassing feed water heater 15.
[0017]
FIG. 2 is a configuration diagram of another gas turbine power generator according to the present invention. In this embodiment, the gas turbine power generation device 10 is a combined cycle including the steam turbine 7, and a part of the steam that has exited the steam generator 13 is supplied to the steam turbine 7 through the steam line 18a. ing. Other configurations are the same as those in FIG. With this configuration, high thermal efficiency can be achieved in the same manner as in FIG. 1, and the efficiency of the combined cycle can be increased by supplying the steam turbine.
[0018]
As described above, in the present invention, in addition to sensible heat cooling with makeup water (cooling water), a part of the sensible heat is led to a steam generator to enhance the cooling effect on the air side, and the generated steam is introduced into the turbine for output. To increase. That is, the intermediate cooler 14 is composed of the steam generator 12 and the gas-liquid heat exchanger 13, and the compressed air that has exited the low-pressure compressor 1 a is first introduced into the steam generator 13, and the compressed air that exits the steam generator 13. Enters the gas-liquid heat exchanger 12, is further cooled with makeup water, and enters the high-pressure compressor. With this configuration, the amount that cannot be cooled by only sensible heat of a small amount of cooling water (makeup water) can be further cooled using the latent heat of water (evaporation heat).
[0019]
On the other hand, the supplied cooling water (make-up water) is preheated by the gas-liquid heat exchanger 12, and a part of the make-up water (line 17b) exiting the gas-liquid heat exchanger 12 is evaporated by the steam generator 13, and the turbine Since it is introduced into (gas turbine 5b or steam turbine 7), power can be recovered from the steam generated by cooling of the compressed air, thereby further improving the efficiency of the plant.
[0020]
Further, most of the cooling water (makeup water) heated by the gas-liquid heat exchanger 12 is sent to the degassing water heater 15 as boiler feed water, and a part of the steam generated by the steam generator 13 is heated by degassing water supply. The boiler feed water can be heated to the saturation temperature by this steam by sending it to the vessel 15, and the boiler feed water can be deaerated. The steam generated by the cooling of the compressed air can be used not only for power recovery but also for heating the deaerator. This can also be used for saving the steam that has been required in the past and further improving the efficiency of the plant.
[0021]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.
[0022]
【The invention's effect】
As described above, the gas turbine power generation device of the present invention can intermediately cool a large amount of heat without increasing the amount of cooling water beyond the amount of makeup water, thereby achieving higher thermal efficiency than before. And so on.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a gas turbine power generator according to the present invention.
FIG. 2 is a configuration diagram of another gas turbine power generator according to the present invention.
FIG. 3 is a configuration diagram of a CHAT cycle using an intercooler.
FIG. 4 is a configuration diagram of an ISTIG cycle.
FIG. 5 is a configuration diagram of a next generation combined cycle in which intermediate cooling is performed.
[Explanation of symbols]
1a, 1b, 1c, 1d Compressor 2 Saturator 3 Exhaust heat recovery devices 4, 4a, 4b Combustors 5, 5a, 5b Turbine 6 Intermediate cooler 7 Steam turbine 8 Mixer 9 Generator 10 Gas turbine power generator 12 Gas-liquid Heat exchanger 13 Steam generator 14 Intermediate cooler 15 Dearator (deaerated feed water heater)
15a chiller 16a, 16b heat exchanger 17a, 17b preheated water supply line 18a, 18b steam line 19 stack (chimney)

Claims (3)

An intermediate cooler comprising a gas-liquid heat exchanger and a steam generator is provided between the compressors,
The steam generator and the gas-liquid heat exchanger, the steam generator of compressed air by the low-pressure side compressor is disposed to cool in the order of the gas-liquid heat exchanger,
Preheated cooling water (makeup water) in the gas-liquid heat exchanger, at least a portion of said cooling water preheated by the gas-liquid heat exchanger is evaporated in the steam generator, the generated steam to a turbine Configured to supply,
A gas turbine power generator characterized by that. A portion of the cooling water heated in the gas-liquid heat exchanger (makeup water) sent to the deaerator feed water heater as boiler feed water, the portion of the steam generated in the steam generator to the deaerator feed water heater feed, thereby heating said boiler feed water to the saturation temperature is degassed, the supplies the remaining steam leaving the steam generator to the turbine, it gas turbine power generation according to claim 1, wherein apparatus.   The gas turbine power generator according to claim 1 or 2, wherein the turbine for supplying steam is a gas turbine or a steam turbine.

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