JPH10231710A - Gas turbine generator - Google Patents

Abstract

(57) [Problem] To provide a gas turbine generator capable of intercooling a large amount of heat without increasing the amount of cooling water to more than the amount of make-up water, thereby achieving higher thermal efficiency than ever before. provide. SOLUTION: An intermediate cooler 14 comprising a gas-liquid heat exchanger 12 and a steam generator 13 is provided between a plurality of compressors 1a and 1b, and compressed air from the low-pressure side compressor 1a is supplied to a steam generator.
The cooling is performed in the order of the gas-liquid heat exchanger, the cooling water is preheated by the gas-liquid heat exchanger, and at least a part thereof is evaporated by the steam generator, and the generated steam is supplied to the turbine 5b. Further, a part of the cooling water heated by the gas-liquid heat exchanger 12 is sent to the degassing feedwater heater 15 as boiler feedwater, and a part of the steam generated by the steam generator is sent to the degassing feedwater heater. The boiler feed water is heated to the saturation temperature and degassed. The turbine that supplies steam is a gas turbine or a steam turbine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas turbine power generator, and more particularly, to a gas turbine power generator for performing intermediate cooling and steam injection.

[0002]

2. Description of the Related Art In a power generating apparatus using a gas turbine, a steam-injected gas turbine cycle (Steam-Injected) for improving performance by injecting steam into air or combustion gas.
Gas Turbine: STIG cycle or CHEN cycle), and a gas turbine cycle (Intercooled and Steam-Injected Gas) equipped with an intercooler to perform intercooling and steam injection
Turbine: ISTIG cycle) is known (for example, "A
n Assessment of the Thermodynamic Performance of M
ixed Gas-Steam Cycles: Part A-Intercooled and Steam
-Injected Cycles ", Journal of Engineering for Gas
Turbine, Vol. 117, July 1995).

FIG. 3 shows a recombustion type CH using an intercooler.
This is an example of an AT cycle in which air A is supplied to the compressors 1a and 1a.
b, 1c, 1d, contains moisture in the saturator 2, is preheated in the exhaust heat recovery device 3, is supplied to the combustors 4a, 4b, and burns the separately preheated fuel F to produce a high-temperature gas E
The high-temperature gas E causes the high-pressure turbine 5a and the low-pressure turbine 5b to rotate to generate power, and the exhaust heat recovery device 3 recovers exhaust heat. In this cycle, an intercooler 6 is provided between the compressors 1b, 1c and 1d, and achieves a thermal efficiency of 54.7% when the inlet temperature of the low-pressure gas turbine is 1394 ° C. In addition, in this figure, 9 is a generator.

FIG. 4 shows an example of the ISTIG cycle reported in the above-mentioned document. As shown in FIG. 4 (A), this cycle is a combined cycle including a steam turbine 7 in addition to the intercooler 6, and the air mixed with steam in the mixer 8 is supplied to the combustor 4 to improve the thermal efficiency. It is supposed to improve. The other basic configuration is similar to that of FIG. 3 except that there is no saturator and low pressure combustor.
It is almost the same as the T cycle. In this ISTIG cycle, as shown in FIG. 4B, when the gas turbine inlet temperature is 1500 ° C., a thermal efficiency of about 53% is achieved.

FIG. 5 shows an example of a next-generation combined cycle for performing intercooling. As shown in FIG. 4, an intercooler 6 and a steam turbine 7 are provided, and power is generated by both the gas turbine 5b and the steam turbine 7, respectively. It has become.
Note that, in addition to FIGS. 3 to 5, water may be directly injected into the compressed air without using an intercooler.

[0006]

The above-described CHAT cycle, ISTIG cycle, and next-generation combined cycle achieve higher thermal efficiency (about 53% at a gas turbine inlet temperature of 1500 ° C.) as compared with existing gas turbine power generators. ing. However, in these intercoolers, the compressed air is cooled by cooling water (make-up water or external cooling water),
Make-up water is used as steam injected into the turbine and is released to the atmosphere after completing work in the turbine. This amount is usually about 10 to 15% by weight of the intake air amount. If the outlet temperature of the low-pressure compressor is 100 ° C or less, the amount of air supplied to the combustor can be cooled to about 40 to 50 ° C. it can. However, when the compression ratio of the low-pressure compressor is increased to improve the cycle efficiency, the outlet temperature becomes 150 ° C. or more, and accordingly, it is necessary to increase the amount of external cooling water to lower the outlet air temperature, and the amount of air discharged is reduced. The amount of heat loss increases. Further, if the makeup water is used as it is, the outlet temperature becomes high and the effect of the intermediate cooling cannot be sufficiently obtained. Further, the means for directly injecting and injecting water can cool the device, but adds steam, which causes a problem that the driving power of the high-pressure compressor increases.

The present invention has been made to solve the above-mentioned 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 ever before. It is in.

[0008]

According to the present invention, an intermediate cooler comprising a gas-liquid heat exchanger and a steam generator is provided in the middle of a plurality of compressors, and compressed air from the low-pressure side compressor is supplied to the steam generator. Cooling in the order of the gas-liquid heat exchanger, preheating the cooling water with the gas-liquid heat exchanger, then evaporating at least a part of the cooling water with the steam generator, and supplying the generated steam to the turbine. Is provided.

According to the present invention, in addition to sensible heat cooling with make-up 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 characterized by the following. That is, the intercooler is composed of a steam generator and a gas-liquid heat exchanger, and the compressed air exiting the low-pressure compressor is first introduced into the steam generator, and the compressed air exiting the steam generator is supplied to the gas-liquid heat exchanger. And further cooled by make-up water before entering the high-pressure compressor. With this configuration, the part that cannot be completely cooled by only the sensible heat of the small amount of cooling water (supply water) can be further cooled by using the latent heat (evaporation heat) of water.

On the other hand, the supplied cooling water (make-up water) is preheated by a gas-liquid heat exchanger, and a part of the make-up water exiting the gas-liquid heat exchanger is evaporated by a steam generator and introduced into a turbine. Therefore, power can be recovered from the steam generated by cooling the compressed air,
Thereby, the efficiency of the plant can be further improved.

According to a preferred embodiment of the present invention, a part of the cooling water (make-up water) heated by the gas-liquid heat exchanger is sent to the degassing feedwater heater as boiler feedwater, and the steam generated by the steam generator is removed. A portion is sent to a degassing feedwater heater, which heats the boiler feedwater to a saturation temperature to degas, and supplies the remaining steam leaving the steam generator to a turbine. That is, by sending most of the cooling water (make-up water) heated by the gas-liquid heat exchanger to the degassing feedwater heater, and further sending a part of the steam generated by the steam generator to the degassing feedwater heater, This steam can be used to heat the boiler feedwater to the saturation temperature and degas the boiler feedwater, and the steam generated by cooling the compressed air can be used not only for power recovery but also for heating the deaerator, The conventionally required steam can be saved, and the efficiency of the plant can be further improved.

The turbine for supplying steam is a gas turbine or a steam turbine. In other words, the efficiency of a gas turbine power generator without a steam turbine can be increased by using a gas turbine as a turbine that introduces generated steam to increase the output, or the efficiency of a combined cycle can be increased by supplying the gas turbine to a steam turbine. You can also.

[0013]

Preferred embodiments of the present invention will be described below with reference to the drawings. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description will be omitted. FIG. 1 is a configuration diagram of a gas turbine power generation device according to the present invention. In this figure, a gas turbine power generator 10 of the present invention includes an intercooler 14 including a gas-liquid heat exchanger 12 and a steam generator 13 between a plurality of compressors (a low-pressure compressor 1a and a high-pressure compressor 1b). 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 the compressed air, and the compressed air generated by the low-pressure side compressor 1a is supplied to the steam generator. 13. The cooling is performed in the order of the gas-liquid heat exchanger 12, 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 are preferably plate-fin heat exchangers, but may be ordinary shell-and-tube heat exchangers.

In FIG. 1, reference numeral 15 denotes a deaerator (a degassing feed water heater), 15a denotes a vent condenser, and 16a, 1
6b is a heat exchanger, 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 deaerated water heater 15 as boiler water via the water supply line 17a, and the steam generated by the steam generator 13 Part of the steam line 18b
To the deaeration / feed water heater 15 through which the boiler feed water is heated to the saturation temperature to be deaerated, and the remaining steam exiting the steam generator 13 is passed through the steam line 18a to the low-pressure turbine 5b. To be supplied.

As a result of trial calculation of the heat balance of the gas turbine power generator 10 shown in FIG. 1, it was confirmed that when the high-pressure turbine inlet temperature was about 1500 ° C., a power generation output of 179 MW and a thermal efficiency of 55.3% could be achieved. That is,
As compared with the conventional gas turbine power generator shown in FIGS.
High thermal efficiency of 6 to 2% or more can be achieved.

In this case, 129 tons of the 145 tons of make-up water are sent to the deaerated water heater 15 via the water supply line 17a, and the remaining 15 tons of the steam line 1
The remaining approximately 0.6 ton was supplied to the deaeration / feed water heater 15 through the low pressure turbine 5b via 8a.

FIG. 2 is a configuration diagram of another gas turbine power generator according to the present invention. In this embodiment, the gas turbine power generator 10 is a combined cycle including the steam turbine 7, and a part of the steam exiting the steam generator 13 is supplied to the steam turbine 7 via the steam line 18a. ing. Other configurations are the same as those in FIG.
With this configuration, high thermal efficiency can be achieved as in FIG. 1, and the efficiency of the combined cycle can be increased by supplying the heat to the steam turbine.

As described above, according to the present invention, in addition to sensible heat cooling with make-up water (cooling water), part of the sensible heat is guided to a steam generator to enhance the cooling effect on the air side and introduce the generated steam into the turbine. And to increase the output. That is, the intercooler 14 is constituted by the steam generator 12 and the gas-liquid heat exchanger 13,
The compressed air that has exited the low-pressure compressor 1a is first introduced into the steam generator 13, and the compressed air that has exited the steam generator 13 enters the gas-liquid heat exchanger 12, where it is further cooled with make-up water, and enter. With this configuration, the part that cannot be completely cooled by only the sensible heat of the small amount of cooling water (supply water) can be further cooled by using the latent heat (evaporation heat) of water.

On the other hand, the supplied cooling water (supplementary water) is preheated in the gas-liquid heat exchanger 12, and a part of the make-up water (line 17 b) exiting the gas-liquid heat exchanger 12 is evaporated in the steam generator 13. And
Since the steam is introduced into the turbine (the gas turbine 5b or the steam turbine 7), power can be recovered from the steam generated by cooling the compressed air, whereby the efficiency of the plant can be further improved.

Most of the cooling water (make-up water) heated by the gas-liquid heat exchanger 12 is sent to the deaeration water heater 15 as boiler water, and a part of the steam generated by the steam generator 13 is removed. By sending the steam to the gas feed water heater 15, the steam can heat the boiler feed water to the saturation temperature to degas the boiler feed water. The steam generated by cooling the compressed air can be used not only for power recovery but also for degassing. It can also be used to heat the vessel, saving the steam previously required and further improving the efficiency of the plant.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[0022]

As described above, the gas turbine power generator of the present invention can intercool a large amount of heat without increasing the amount of cooling water to more than the amount of makeup water, thereby achieving higher thermal efficiency than conventional ones. It has excellent effects such as can be achieved.

[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 generation device 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 for performing intermediate cooling.

[Explanation of symbols]

 1a, 1b, 1c, 1d Compressor 2 Saturator 3 Exhaust heat recovery device 4, 4a, 4b Combustor 5, 5a, 5b Turbine 6 Intercooler 7 Steam turbine 8 Mixer 9 Generator 10 Gas turbine generator 12 Gas-liquid Heat exchanger 13 Steam generator 14 Intercooler 15 Deaerator (degasified feed water heater) 15a Deaerator cooler 16a, 16b Heat exchanger 17a, 17b Preheated water supply line 18a, 18b Steam line 19 Stack (chimney)

──────────────────────────────────────────────────の Continued on front page (51) Int.Cl. ⁶ Identification code FI F02C 7/143 F02C 7/143

Claims (3)

[Claims] An intermediate cooler comprising a gas-liquid heat exchanger and a steam generator is provided between a plurality of compressors, and the compressed air from the low-pressure side compressor is cooled in the order of a steam generator and a gas-liquid heat exchanger. And
A gas turbine power generator, wherein a cooling water (supplementary water) is preheated by a gas-liquid heat exchanger, then at least a part thereof is evaporated by a steam generator, and the generated steam is supplied to a turbine. 2. A part of the cooling water (make-up water) heated by the gas-liquid heat exchanger is sent to the degassing feedwater heater as boiler feedwater, and a part of the steam generated by the steam generator is sent to the degassing feedwater heater. The gas turbine generator according to claim 1, wherein the steam is supplied to the steam generator, whereby the boiler feed water is heated to a saturation temperature and deaerated, and the remaining steam exiting the steam generator is supplied to a turbine. . 3. The gas turbine power generation apparatus according to claim 1, wherein the turbine that supplies steam is a gas turbine or a steam turbine.