JP2002371861A - Steam injection gas turbine generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam injection gas turbine generator capable of (1) recovering a part of the latent heat vaporization of steam generated by recovering the exhaust heat as the work, (2) reducing exergy losses when recovering the exhaust heat by generating high-pressure/low-pressure steam without using a plurality of boiler drums, and (3) preventing generation of fuming caused by steam condensation in the atmosphere. SOLUTION: This steam injection gas turbine generator comprises a steam expander 12 for recovering the power by expanding saturated steam generated in an exhaust heat recovery boiler 3b, and a steam separator 14 for separating wet steam from the steam expander into saturated steam and saturated water. The separated saturated water is mixed in feed water to an economizer, and the separated saturated steam is superheated in a superheater 3c and injected in a combustor 1b. An expansion valve 16 is provided for flushing the saturated water from the economizer 3a and feeding it to the steam separator 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam-injected gas turbine power generator for injecting steam into a gas turbine to generate power and generate steam.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing an example of a conventional steam injection gas turbine power generator. In this figure, 1 is a gas turbine, 2 is a generator, and 3 is an exhaust heat recovery facility.
The gas turbine 1 includes a compressor 1a, a combustor 1b, and a turbine 1
c, and drives the generator 2 via the reduction gear 2a to generate power. The exhaust heat recovery equipment 3 is an economizer 3 in this example.
a, an exhaust heat recovery boiler 3b, and a superheater 3c, which heats feed water from a feed water pump 3d with exhaust gas from the turbine 1c to generate superheated steam. The generated superheated steam is supplied to the combustor 1
b.

The above-described steam-injected gas turbine power generator generates saturated steam by exhaust heat of the gas turbine, superheats the saturated steam with the exhaust gas, and then injects the saturated steam into a combustor of the gas turbine to exhaust the gas turbine. It recovers heat and converts it into motive power.It has the characteristic that the flow rate of the combustion gas flowing into the turbine increases, and the specific heat of the combustion gas increases, thereby increasing the output and thermal efficiency of the turbine. I have. As a typical example of the steam injection gas turbine, a "two-working fluid heat engine" of Japanese Patent Publication No. 54-34865 is known.

[0004]

In the above-described conventional steam-injected gas turbine power generator, the latent heat of vaporization of the steam given by the exhaust heat of the gas turbine is not finally recovered as work, but is discarded into the atmosphere together with the exhaust gas. There is a problem that is done. In order to reduce exergy loss in exhaust heat recovery, it is generally used to make recovered steam a double pressure, but in this case, a plurality of boiler drums such as high pressure / low pressure are required, and the system becomes complicated. There is a point. Further, the conventional steam-injected gas turbine power generator has a problem that the ratio of water vapor in the exhaust gas is high (for example, about 30% in volume ratio), and the water vapor is easily condensed in the atmosphere to generate white smoke.

The present invention has been made to solve such a problem. That is, the object of the present invention is:
(1) Part of the latent heat of vaporization of steam generated by collecting exhaust heat can be collected as work. (2) High-pressure / low-pressure steam is generated without using multiple boiler drums to recover exhaust heat. (3) To provide a steam injection gas turbine power generation device capable of reducing (3) generation of white smoke due to condensation of water vapor in the atmosphere.

[0006]

According to the present invention, a gas turbine (1) including a compressor (1a), a combustor (1b), and a turbine (1c), an economizer (3a), an exhaust heat recovery boiler ( 3b), in a steam injection gas turbine power generation device comprising a superheater (3c) and an exhaust heat recovery facility (3) for recovering the exhaust heat of the turbine, the saturated steam generated in the exhaust heat recovery boiler (3b) is removed. A steam expander (12) for expanding and recovering power, and a brackish water separator (14) for separating wet steam exiting the steam expander into saturated steam and saturated water, and separating the separated saturated water into an economizer. The saturated steam mixed and separated into the feed water is supplied to the circulating water flow control valve (14a).
Through the superheater (3c) and the superheater (1b)
And a steam injection gas turbine power generator.

According to the configuration of the present invention, since the saturated water separated from the wet steam by the steam separator (14) is mixed into the water supply to the economizer, the latent heat of evaporation of the saturated steam generated in the exhaust heat recovery boiler (3b) is obtained. Can be recovered as a steam expander output. Also, due to this saturated water circulation,
The temperature of the feedwater flowing into the economizer increases, and accordingly, the temperature of exhaust gas discharged into the atmosphere can be increased without using an extra heat source, thereby preventing the generation of white smoke. Also,
Since the saturated steam pressure of the exhaust heat recovery boiler (3b) before being expanded by the steam expander (12) can be set sufficiently higher than the pressure of steam injected into the combustor (1b), the steam expander (12 ), The power can be further recovered by the turbine (1c).

According to a preferred embodiment of the present invention, a circulating water flow control valve (1) for controlling the flow rate of the saturated water mixed in the water supply to the economizer (3a) to prevent white smoke.
4a). With this configuration, white water can be prevented and the circulating water amount of the saturated water can be adjusted to an optimal flow rate with less exergy loss by the circulating water amount control valve (14a) according to the temperature and humidity of the outside air.

Further, the saturated water discharged from the economizer (3a) is flushed, and this is flushed with the brackish water separator (14).
And an expansion valve (16) for supplying the pressure to the expansion valve. With this configuration,
Saturated water and saturated steam are separated by the steam separator (14) from the low-pressure wet steam generated by the flush of the high-pressure saturated water. By separating the saturated water, the latent heat of steam released in the steam expander can be used effectively,
Separated saturated steam can be used as steam equivalent to low-pressure steam in a double-pressure boiler having a plurality of drums.

In addition, an inline mixing superheater (18) for mixing a part of the saturated steam separated by the steam separator (14) with the makeup water supplied to the economizer (3a) is provided. With this configuration, when the temperature and humidity of the outside air are particularly likely to generate white smoke, the temperature of the water supply is greatly increased using the latent heat of the saturated steam, and the temperature of the exhaust gas discharged into the atmosphere without using an extra heat source Can be greatly increased to prevent the generation of white smoke.

The in-line mixing superheater (18)
And a steam flow control valve (18a) for controlling the flow rate of the saturated steam supplied to the tank to prevent white smoke. With this configuration, even if the temperature and humidity of the outside air are particularly likely to generate white smoke, the steam flow control valve (18a) prevents the white smoke and adjusts the supply flow rate of the saturated steam to an optimal flow rate with less exergy loss. be able to.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. Note that the same reference numerals are used for common parts in each drawing.

FIGS. 8 and 9 are exhaust heat recovery diagrams of a conventional steam injection gas turbine power generator. In these figures, the horizontal axis represents the amount of heat exchanged when recovering gas turbine exhaust heat,
The vertical axis is temperature. The abscissa specifically corresponds to the enthalpy of gas turbine exhaust gas based on 0 ° C.
In these figures, the gas turbine exhaust gas is approximately 550
The water is cooled from the temperature to 144 ° C., and the amount of heat is used to heat the water to the saturation temperature, evaporate at the saturation temperature into saturated steam, and further heat to superheated steam. In this example, FIG. 8 shows a case where the saturated steam pressure is single (about 15 ata), the power generation output is about 6128 kW, and the power generation efficiency is about 38.9%. FIG. 9 shows the case of double pressure (about 15 ata and about 63 ata), and under the same conditions, the power generation output reaches about 6449 kW and the power generation efficiency reaches about 40.5%.

FIG. 10 is a diagram showing the relationship between the generation state of white smoke and exhaust gas conditions. In this figure, the horizontal axis is temperature,
The vertical axis is absolute humidity, the curve in the figure is a saturation line at 100% humidity,
Two points A and B in the figure show the state of the atmosphere and the exhaust. When the state of exhaust gas, that is, the exhaust gas (exhaust gas turbine exhaust gas) into the atmosphere (temperature and absolute humidity) is, for example, the point B in the drawing, the discharged exhaust gas gradually changes to the state A of the atmosphere while being diffused into the atmosphere. . During this process, the state of exhaust is 100% humidity
It is considered that the water vapor in the exhaust gas condenses into white smoke above the saturation line in FIG. Therefore, a virtual line is drawn from the exhaust state B to the atmospheric state A, and the generation of white smoke can be predicted based on whether this line intersects the saturation line.

8 and 9, the temperature and humidity of the exhaust gas from the gas turbine are substantially constant. On the other hand, since the state A of the atmosphere changes every moment, white smoke is not generated or generated in the conventional apparatus depending on the atmospheric state. For this reason, when white smoke is generated, the conventional apparatus shifts the exhaust state B in the direction indicated by a straight arrow in the figure to prevent white smoke by heating exhaust gas or the like. However, this requires extra energy, and the power generation efficiency is reduced accordingly.

FIG. 1 is a configuration diagram of a first embodiment of a steam injection gas turbine power generator according to the present invention. Referring to FIG. 1, a steam injection gas turbine power generator 10 of the present invention includes a gas turbine 1 including a compressor 1a, a combustor 1b, and a turbine 1c, and a turbine 1c including an economizer 3a, an exhaust heat recovery boiler 3b, and a superheater 3c. And an exhaust heat recovery facility 3 for recovering exhaust heat. These configurations are the same as the conventional one, but the saturation pressure of the exhaust heat recovery boiler 3b is set higher than the conventional one.

The steam-injected gas turbine power generator 10 shown in FIG.
Further includes a steam expander 12 that expands saturated steam generated in the exhaust heat recovery boiler 3b to recover power and a steam expander 1
And a brackish water separator 14 for separating the wet steam that has exited from Step 2 into saturated steam and saturated water. Further, a circulating water flow control valve 14 for controlling the flow rate of the saturated water mixed into the water supply of the economizer 3a to an optimum flow rate for preventing white smoke and reducing exergy loss.
a. The saturated water separated by the brackish water separator 14 is mixed into the feed water of the economizer 3a via the circulating water flow control valve 14a, heating the feed water and increasing its flow rate. The saturated steam separated by the steam separator 14 is supplied to the superheater 3c, and only the saturated steam without condensed water is supplied to the superheater 3c.
c to be heated and injected into the combustor 1b.
In this figure, reference numeral 3e denotes a pump for supplying water. Further, in this example, the steam expander 12
a is driven to increase the power generation output. As another measure, it is also possible to drive a pump, a compressor and the like.

FIG. 2 is an exhaust heat recovery diagram of FIG. In this figure, the saturated steam pressure is set to about 63 ata, which is higher than the conventional value. Further, the exhaust temperature of the exhaust gas of the gas turbine has risen to about 189 ° C. due to the influence of the saturated water circulation by the circulating water flow control valve 14a. Further, in this example, the power generation output is about 5894 kW and the power generation efficiency is about 38.9%. That is, in comparison with the conventional example of FIG. 8, the power generation output is slightly reduced, but the power generation efficiency can be kept the same and the generation of white smoke can be prevented.

According to the configuration of the present invention described above, the saturated water separated from the wet steam by the steam separator 14 is supplied to the economizer 3.
By mixing the water into the water supply a, a part of the latent heat of the steam recovered by the steam expander 12 can be recovered without re-consumption. In addition, the temperature of feedwater flowing into the economizer is increased by the circulation of the saturated water, and accordingly, the temperature of exhaust gas discharged into the atmosphere can be increased and the generation of white smoke can be prevented without using an extra heat source. Further, since the saturated steam pressure of the exhaust heat recovery boiler 3b before being expanded by the steam expander 12 can be set sufficiently higher than the saturated steam pressure injected into the combustor 1b, a high pressure can be obtained without using a plurality of boiler drums. / Low pressure steam is generated to reduce exergy loss in exhaust heat recovery. Further, since the power is recovered by the steam expander 12, the power generation output can be further increased.

In other words, in the conventional steam-injected gas turbine power generator, when exhaust heat is recovered by steam and steam is injected, the exhaust heat used for evaporation of steam is eventually discarded into the atmosphere. In the steam-injected gas turbine power generator 10 of the present invention shown in FIG. 1, by removing condensed water from the wet steam after work in the steam expander, a part of the latent heat of evaporation is converted into shaft power or gas turbine power. The working fluid is recovered as sensible heat, and the thermal efficiency of the gas turbine can be further improved.

FIG. 3 is a diagram showing a second embodiment of the present invention.
In this figure, the steam injection gas turbine power generator 10 of the present invention further includes an expansion valve 16 for flushing the saturated water flowing out of the economizer 3a and supplying the same to the brackish water separator 14. Other configurations are the same as those in FIG. According to the configuration of FIG. 3, saturated water and saturated steam are separated by the steam separator 14 from low-pressure wet steam generated by the flush of high-pressure saturated water. By separating saturated water, the latent heat of steam released in the steam expander can be used effectively, and the separated saturated steam is used as steam equivalent to low-pressure steam in a multiple-pressure boiler with multiple drums. can do.

FIG. 4 is an exhaust heat recovery diagram of FIG. In this figure, the saturated steam pressure is set to about 63 ata, which is higher than in the prior art, as in FIG. Further, the exhaust temperature of the exhaust gas of the gas turbine rises to about 156 ° C. due to the influence of the saturated water circulation by the circulating water flow control valve 14a. Further, in this example, the power generation output is about 6364 kW and the power generation efficiency is about 40.3
%. That is, in comparison with the related art in FIG. 8, the power generation output increases, the power generation efficiency improves, and the generation of white smoke can be prevented.

The device of FIG. 3 operates as follows. 1. The high-pressure steam generated by the exhaust heat recovery is applied to the steam expander 1
2, the shaft power is generated, the low-pressure steam from the expansion valve 16 is added to the completed steam, and the steam is superheated by the superheater 3c and then re-worked by the turbine 1c via the gas turbine combustor 1b. . 2. By expanding the high-pressure saturated water from the economizer 3a to the outlet pressure of the steam expander 12 with the expansion valve 16, the saturated water is flushed, low-pressure steam is generated, and a gas-liquid mixed phase state is established. This is separated into saturated water and saturated steam by the downstream steam separator 14, and the saturated water is returned to the water supply system of the boiler. The separated saturated steam is superheated by the superheater 3c and then injected into the gas turbine combustor 1b. 3. The outlet of the steam expander 12 is in a state of wet steam containing condensed water. The wet steam is mixed with the steam / water-liquid mixed phase flow from the expansion valve 16 and is separated into saturated steam and saturated water by the steam separator 14. 4. Since the saturated water separated by the brackish water separator 14 has a pressure at an intermediate level between the makeup water supply pressure and the high-pressure steam pressure, in order to return the saturated water to the water supply line, the saturated water is appropriately placed before and after the mixing point of the water supply line. Install a water supply pump with an appropriate pressure ratio. 5. The saturated steam that has exited the steam separator 14 is superheated by the superheater 3c and then injected into the gas turbine combustor 1b. Note that a variable thermoelectric gas turbine cogeneration can be configured by weighing and extracting a part of the saturated steam before the superheater and sending it to the process.

FIG. 5 is a diagram showing a third embodiment of the present invention.
In this figure, a steam injection gas turbine power generator 10 of the present invention includes an inline mixing superheater 18 that mixes a part of the saturated steam separated by the brackish water separator 14 with the makeup water supplied to the economizer 3a, A steam flow control valve 18a for adjusting the flow rate of the saturated steam supplied to the vessel 18 to prevent white smoke is provided. Further, as described above, a thermoelectric variable gas turbine cogeneration may be configured such that a part of the saturated steam is metered and extracted before the superheater and sent to the process.

FIG. 6 is an exhaust heat recovery diagram of FIG. In this figure, the saturated steam pressure is set to about 63 ata, which is higher than in the prior art, as in FIG. Further, the exhaust temperature of the gas turbine exhaust gas has risen to about 202 ° C. due to the influence of the saturated steam by the in-line mixing superheater 18. Further, in this example, the power generation output is about 5,821 kW, and the power generation efficiency is about 38.7.
%. That is, in this example, the power generation output decreases,
Although the power generation efficiency also decreases, even when the temperature and humidity of the outside air are particularly likely to generate white smoke, the exhaust state can be largely moved to the lower right direction in FIG. 10 and even when the outside air state is very bad,
The generation of white smoke can be prevented. Further, the state shown in FIG. 3 can be returned at any time by the steam flow control valve 18a.
White smoke can be prevented, and the supply flow rate of saturated steam can be adjusted to an optimum flow rate with less exergy loss.

In other words, in the above-described steam-injected gas turbine power generator of the present invention, the prevention of white smoke is realized by adjusting both the reduction of the absolute humidity in the exhaust gas and the increase of the exhaust gas temperature. That is, the exhaust gas temperature rises due to the high-temperature saturated water separated by the brackish water separator 14, and a part of the saturated steam separated by the brackish water separator 14 is returned to the water supply system and mixed with the feedwater to raise the feedwater temperature to increase the exhaust gas temperature. At the same time as the temperature is increased, the steam extraction to the gas turbine is reduced by the bleed air, so that the absolute humidity in the exhaust gas can be reduced.

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

[0028]

According to the present invention, the following effects can be obtained. 1. The condensed water (mist) contained at the outlet of the steam expander is a result of converting a part of the latent heat of the steam by the exhaust heat recovery into the shaft power of the expander and the sensible heat of the steam. The latent heat of evaporation contained in the exhaust gas is effectively recovered, and the cycle efficiency is improved. 2. The operation of circulating water from the economizer to the economizer again through the expansion valve and the brackish water separator, and obtaining low-pressure steam as flash steam in the process, can produce low-pressure steam without a boiler drum and at the same time, at the outlet of the expansion valve. It also plays a role in creating a gas-liquid mixed phase state with an overwhelmingly large liquid phase. This condition makes it possible to efficiently separate the condensate mist slightly contained in the steam exiting the steam expander. An effect equivalent to exhaust heat recovery by double-pressure steam for improving cycle efficiency can be realized with one drum.

Therefore, the steam injection gas turbine power generator of the present invention can (1) recover a part of the latent heat of vaporization of steam generated by recovering exhaust heat, and (2) a plurality of boiler drums. Exergy loss in waste heat recovery can be reduced by generating high-pressure / low-pressure steam without using
(3) It has excellent effects such as prevention of generation of white smoke due to condensation of water vapor in the atmosphere.

[Brief description of the drawings]

FIG. 1 is a first view of a steam injection gas turbine power generator according to the present invention.
It is a lineblock diagram of an embodiment.

FIG. 2 is an exhaust heat recovery diagram of FIG.

FIG. 3 is a diagram of a second embodiment of the present invention.

FIG. 4 is an exhaust heat recovery diagram of FIG. 3;

FIG. 5 is a diagram of a third embodiment of the present invention.

6 is an exhaust heat recovery diagram of FIG.

FIG. 7 is a configuration diagram of a conventional steam injection gas turbine power generator.

FIG. 8 is an exhaust heat recovery diagram of FIG. 7;

FIG. 9 is an exhaust heat recovery diagram of a conventional double-pressure steam injection gas turbine power generator.

FIG. 10 is a diagram showing a relationship between a white smoke generation state and exhaust gas conditions.

[Explanation of symbols]

1 gas turbine, 1a compressor, 1b combustor, 1c
Turbine, 2 generator, 2a reduction gear, 3 waste heat recovery equipment, 3a economizer, 3b waste heat recovery boiler, 3
c Superheater, 3d feedwater pump, 10 steam injection gas turbine generator, 12 steam expander, 14 steam separator, 14a circulating water flow control valve, 16 expansion valve, 18 in-line mixing superheater, 18a steam flow control valve

[Procedure amendment]

[Submission date] June 18, 2001 (2001.6.1)
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

According to the present invention, a gas turbine (1) including a compressor (1a), a combustor (1b), and a turbine (1c), an economizer (3a), an exhaust heat recovery boiler ( 3b), in a steam injection gas turbine power generation device comprising a superheater (3c) and an exhaust heat recovery facility (3) for recovering the exhaust heat of the turbine, the saturated steam generated in the exhaust heat recovery boiler (3b) is removed. A steam expander (12) for expanding and recovering power, and a brackish water separator (14) for separating wet steam exiting the steam expander into a saturated steam and a saturated water. A steam injection gas turbine power generator is provided, wherein the saturated steam mixed into feed water and separated is superheated by a superheater (3c) and injected into the combustor (1b).

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) F01K 23/10 F01K 23/10 CT F22B 1/18 F22B 1/18 D F22G 1/04 F22G 1/04

Claims (5)

[Claims] 1. A gas turbine (1) comprising a compressor (1a), a combustor (1b) and a turbine (1c), an economizer (3a), an exhaust heat recovery boiler (3b), and a superheater (3).
(c) a steam injection gas turbine power generator having an exhaust heat recovery facility (3) for recovering the exhaust heat of the turbine, and recovering power by expanding saturated steam generated in the exhaust heat recovery boiler (3b). A steam expander (12); and a brackish water separator (14) for separating wet steam from the steam expander into saturated steam and saturated water. The separated saturated water is passed through a circulating water amount control valve (14a). A steam injection gas turbine power generator, characterized in that said saturated steam mixed into feed water of an economizer is heated by a superheater (3c) and injected into said combustor (1b). 2. A circulating water amount control valve (14a) for controlling a flow rate of the saturated water mixed in the water supply of the economizer (3a) to prevent white smoke. Steam injection gas turbine power plant. 3. An expansion valve (16) according to claim 1, characterized in that it comprises an expansion valve (16) which flushes the saturated water leaving the economizer (3a) and supplies it to the steam separator (14). Steam injection gas turbine power generator. 4. An in-line mixing superheater (18) for mixing a part of the saturated steam separated by the steam separator (14) with makeup water supplied to the economizer (3a).
The steam injection gas turbine power generator according to claim 1, characterized in that: 5. A steam flow control valve (18a) for adjusting a flow rate of saturated steam supplied to the in-line mixing superheater (18) to prevent white smoke. A steam-injected gas turbine power generator according to any of the preceding claims.