JP2000282894A - Gas turbine plant, and operation method and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce production cost and improve power generation output or power generation efficiency by simplifying a moisture highly utilizing gas turbine system for recovering water, miniaturizing elemental equipment and accelerating a low pressure loss. SOLUTION: This gas turbine plant is provided with a humidifier 2 for adding water to the combustion gas pressurized by a compressor, a heat recovery device 3 for recovering heat energy in the exhaust gas from a gas turbine, a water recovery device 6 for recovering water in the exhaust gas, and an exhaust gas re-heating device 7 for adding heat to the exhaust gas before releasing the gas in atmosphere. In this case, the humidifier 2 is provided with an atomizing means for atomizing heated liquid phase water in pressurized gas, redundant water recovering means to recover the redundant water left as liquid phase because of not having vaporized, and a supply means for supplying the water recovered by this redundant water recovering means as water for heating the heat source of the exhaust gas re-heating device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine plant, a method of operating the same, and a method of controlling the same. More particularly, a high-humidity working medium is heated to a high temperature by a combustor, and the gas turbine is driven by the high-temperature gas. The present invention relates to a gas turbine plant that obtains power.

[0002]

2. Description of the Related Art HAT (Humi) using a working medium of high humidity is used.
d Air Turbine (High Humidity Gas Turbine) cycle technology includes, for example, Japanese Patent Publication No. 1-195053, Japanese Patent Publication No. 1-31013, and "Thermal Nuclear Power Generation Vol.43 No.12 1992 p65-p71". Are known.

[0003] In other words, the air used as auxiliary combustion gas and working medium gas, or a gas mainly composed of air is added to a part or all of the compressed air obtained by increasing the pressure of the compressor, and the liquid phase water is added to the compressed air. A gas turbine cycle (plant) for recovering heat from the exhaust gas of a gas turbine or recovering heat from the exhaust gas of a gas turbine and intercooling the compressor using a liquid-phase mixture of compressed air / water / steam obtained by injecting the compressed air / water / steam. It has been disclosed.

In this gas turbine cycle, inflow air is cooled by liquid-phase water in an intercooler and a postcooler in a compression process. The generated compressed air is heated by the exhaust gas in the heat recovery device after being humidified. This gas turbine cycle does not require a steam turbine, and it is considered that a gas turbine alone can achieve a power and efficiency higher than or equal to that of a combined cycle.

[0005]

In the prior art described above, a humidifying tower is employed as a means for humidifying the compressed air supplied to the gas turbine. The detailed structure of the humidification tower is, for example, one described in U.S. Pat. No. 2,186,706. This humidification tower is for bringing compressed air and water into direct contact with each other in countercurrent. That is, in the humidification tower, the sprayed or dropped water droplets are directly brought into contact with the compressed air flowing upward through the porous medium that promotes the contact between the compressed air and the water. We try to add moisture. The water flowing into the humidification tower is usually heated by performing heat recovery, and the liquid water not evaporated in the humidification tower is used again for heat recovery and circulated.

The inside of the humidification tower is not only a counter flow of air and water but also through a porous medium, so that the flow resistance becomes large and a large pressure loss is likely to occur. Further, the compressed air before flowing into the humidification tower performs heat exchange in the post-cooler, and thus also generates a pressure loss here. When the pressure loss of the compressed air is large, the pressure of the working medium flowing into the gas turbine decreases, so that the output of the gas turbine decreases and the thermal efficiency decreases.

Further, in the above-mentioned conventional technology, since the steam added to the compressed air is released to the atmosphere together with the exhaust gas,
The problem of consuming a large amount of water has been pointed out, and countermeasures have been demanded. As an example of solving the problem of mass consumption of water in the above prior art, "IGTI-Vol.7 ASME COGEN-
`` FT4000 HAT WITH NATURAL '' on pages 239-245 of `` TURBO 1992 ''
GAS FUEL, JP-A-10-30811, and JP-A-10-110628 describe systems for recovering moisture from gas turbine exhaust gas and reusing or recycling the same.

However, in this cycle, the exhaust gas is cooled to, for example, about 40 ° C. or lower, which is lower than the temperature at which moisture in the exhaust gas starts to condense (dew point temperature), in order to recover moisture. 90
It is necessary to reheat the exhaust gas to a temperature of at least ° C. In the above prior art, as the reheating medium of the exhaust gas from which the water was recovered,
It is said that heat is exchanged between the gases by using the exhaust gas before collecting the moisture. For this reason, the heat exchange equipment for reheating the exhaust gas becomes large, and the pressure loss of the exhaust gas increases.
Since the exhaust gas pressure at the outlet of the chimney is equal to the atmospheric pressure, if the pressure loss of the exhaust gas from the gas turbine outlet to the chimney increases, the exhaust gas pressure at the gas turbine outlet must be increased. That is, the pressure difference between the working medium at the inlet and the outlet of the gas turbine decreases, and the output of the gas turbine decreases. However, the above-mentioned related art does not consider this point at all.

On the other hand, as an example of humidifying the working medium by another method, Japanese Patent Laid-Open Publication No. Hei 8-232684 discloses that hot water is supplied to a working medium in a heat recovery device without using a post-cooler or a humidification tower. A gas turbine cycle is described for injecting and evaporating. A major feature of this cycle is that the addition of water to the working medium is performed only by injecting water into the working medium in the heat recovery device, and the humidification using a porous medium that causes a pressure loss of the working medium. It has no tower or post-cooler. Also, in this cycle,
All the water in the liquid phase injected into the working medium evaporates and is mixed into the working medium as water vapor, and there is no circulation of water.
However, the above prior art does not consider the case where a water recovery device is present in a cycle, and it is necessary to consider a new optimal cycle configuration when a water recovery device is required.

The present invention has been made in view of the above, and an object of the present invention is to simplify a high-humidity gas turbine system for recovering water, to reduce the size of element devices,
An object of the present invention is to provide a gas turbine plant of this type that can promote reduction in pressure loss and reduce manufacturing costs and improve power generation output or power generation efficiency.

[0011]

That is, the present invention provides a humidifier for adding moisture to combustion gas pressurized by a compressor, a heat recovery device for recovering thermal energy of exhaust gas from a gas turbine, In a gas turbine plant equipped with a water recovery device that recovers moisture in the exhaust gas and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, the humidifying device has a heated liquid phase. Spraying means for spraying water into the pressurized gas; surplus water collecting means for collecting surplus water remaining in a liquid phase without evaporating the sprayed water; and water collected by the surplus water collecting means. And a supply means for supplying water as a heating source water of the exhaust gas reheating device to achieve the intended purpose.

Further, the present invention provides a humidifier for adding moisture to a combustion gas pressurized by a compressor, a heat recovery device for recovering thermal energy of exhaust gas from a gas turbine, and a water recovery device for recovering moisture in the exhaust gas. In a gas turbine plant provided with a water recovery device that performs heating and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, the plant heats the water heated by the heat recovery device into the humidifier. Supply means for supplying water to the humidifier, spray means for spraying the water supplied to the humidifier into the combustion gas, and excess water recovery for collecting excess water remaining in a liquid phase without evaporation of the sprayed water. Means and supply means for supplying the water recovered by the surplus water recovery means as the heating source water of the exhaust gas reheating device.

In this case, the water after the exhaust gas is heated by the exhaust gas reheating device is provided between the exhaust gas reheating device and the heat recovery device as spray water when water is added to the combustion gas. A supply means for supplying the heat recovery device is provided. Also, the heat recovery device generates steam, and the steam is sprayed together with liquid-phase water by the spraying means of the humidifier. Further, the spraying means is formed so as to supply water in excess of a limit amount that can be added as steam to the combustion gas.

The present invention also provides a humidifier for adding moisture to the combustion gas pressurized by the compressor, a heat recovery device for recovering thermal energy of exhaust gas from the gas turbine, and a device for recovering moisture in the exhaust gas. In a method of operating a gas turbine plant comprising a water recovery device to perform, and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, when adding moisture to the combustion gas, The water heated by the recovery device is supplied in the form of spray into the combustion gas, and the excess water remaining in the liquid phase without evaporation of the sprayed water is used as a heating source water of the exhaust gas reheating device. It is like that.

In this case, when the hot water is supplied in the form of a spray to the combustion gas, water is supplied in excess of the limit amount that can be added as steam to the combustion gas. Further, water after exhaust gas heating by the exhaust gas reheating device is supplied to the heat recovery device as spray water when adding moisture to the combustion gas.

Further, the present invention provides a humidifier for adding moisture to a combustion gas pressurized by a compressor, a heat recovery device for recovering thermal energy of exhaust gas from a gas turbine, and a device for recovering moisture in the exhaust gas. In a method for controlling a gas turbine plant comprising a water recovery device to perform, and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, when adding moisture to the combustion gas, The steam generated by the recovery device is supplied in a spray state together with the liquid phase water into the combustion gas, and the excess water remaining in the liquid phase without evaporating the sprayed water is supplied to the exhaust gas reheating device. The gas turbine is used as a heating source water, and the output of the gas turbine is adjusted by adjusting the flow rate, pressure and droplet diameter of the liquid water sprayed in the humidifier.

Further, a humidifier for adding moisture to the combustion gas pressurized by the compressor, a heat recovery device for recovering thermal energy of exhaust gas from the gas turbine, and a water recovery for recovering moisture in the exhaust gas In a control method of a gas turbine plant including a device and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, when adding moisture to the combustion gas, the heat recovery device The heated water or steam is supplied in the form of spray into the combustion gas, and the excess water remaining in the liquid phase without evaporation of the sprayed water is used as the heating source water of the exhaust gas reheating device. The output of the gas turbine is adjusted by adjusting the flow rate and pressure of steam supplied to the humidifier.

That is, in the gas turbine plant formed as described above, the humidifier has a spraying means for spraying the heated liquid-phase water into the pressurized gas, and a liquid-phase water without evaporating the sprayed water. Surplus water collecting means for collecting surplus water remaining as it is, and supply means for supplying water collected by the surplus water collecting means as a heating source water of the exhaust gas reheating device are provided. By adding water to the combustion gas by spraying it, there is no need for a post-cooler or humidification tower, so the pressure loss of the combustion gas is reduced and the humidifier is a heat recovery device from the compressor. Since it can be provided at any position in the flow path, the cycle itself is simplified and the manufacturing cost is reduced. Furthermore, since liquid-phase water is used for exhaust gas reheating, there is no need to pass exhaust gas before water recovery to an exhaust gas reheater.
Since the method of reheating exhaust gas is heat exchange between water and gas, the heat transfer coefficient is high, the exhaust gas reheater can be small, the production cost and pressure loss are reduced, and therefore the pressure loss is reduced. And power generation output or power generation efficiency can be improved.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 is a system diagram showing the gas turbine cycle (plant). In this cycle, high-humidity compressed air is heated by a combustor and expanded by a gas turbine to generate rotational power.

The main components are a compressor 1 that draws in air to increase the pressure, a humidifier (humidifier) 2 that adds moisture to the compressed air, and a heat recovery device 3 that recovers heat from exhaust gas. Combustor (combustion device) that heats compressed air with high humidity
4, a gas turbine 5 that generates rotational power by expanding high-temperature and high-pressure gas, a water recovery device 6 that cools exhaust gas to liquefy water vapor in the exhaust gas, and an exhaust gas reheater 7 that heats the exhaust gas. And a generator 8 for converting rotational power into electric power.

The inflow air 11 is pressurized in the compressor 1 and then mixed and humidified in the humidifying section 2 with hot water 22. The mixing with the hot water is performed by spraying liquid water in the form of fine droplets using a spray nozzle or the like. The amount of water sprayed is about several times the amount that can be added as steam to the compressed air, and surplus water 23 is generated. After sufficient humidification is performed, the surplus water 23 is separated from the air.

Next, the humidified air 13 is supplied to the heat recovery device 3.
After the heat of the exhaust gas is recovered and heated, the gas flows into the combustor 4, generates the high-temperature and high-pressure combustion gas 15 by burning the fuel 31, and expands the combustion gas in the gas turbine 5. The exhaust gas 16 of the gas turbine 5 is cooled in the heat recovery device 3 by heating the humidified air 13 and the water 21 supplied to the humidification unit 2. Care must be taken in the heat recovery device 3 so that the water vapor in the exhaust gas does not liquefy.

Next, in the water recovery device 6, the exhaust gas 17
It is cooled down to around 40 ° C. where the moisture in it condenses. Examples of the cooling method include indirect heat exchange with cooling water and heat exchange by direct contact. This embodiment shows an example using indirect heat exchange. Next, the exhaust gas 18 is supplied to the humidifying section 2.
After being heated to 90 ° C. or higher by the surplus water 23 obtained from

Next, the operation of circulating water will be described. The liquid-phase water 22 heated by performing heat recovery from the exhaust gas in the heat recovery device 3 is sprayed into the compressed air 12 in the humidifying unit 2, and a part of the water 22 is added to the air as steam and goes to the combustor 4. The remaining surplus water 23 is separated and recovered from the air. Although the surplus water 23 is lower than the temperature of the water 22 before being sprayed, it is still about one hundred and several tens degrees, for example, 1
It is as high as 30 ° C. This surplus water 23 is sent to the exhaust gas reheater 7. The surplus water 23 sent from the exhaust gas 1
8 can be heated. The surplus water 23 is cooled by this operation.

On the other hand, the water added to the air as water vapor is recovered as liquid water 24 in the water recovery device 6,
The water passes through the water treatment device 41, is pressurized by the pressurizing pump 43, and merges with the water that has passed through the gas reheater 7. The combined water 21 is sent to the heat recovery device 3 again after being pressurized by the pressurizing pump 42, thereby establishing circulation.

Since the surplus water 23 is cooled by the exhaust gas reheater 7 and merges with the water 25 from the water recovery device 6, the temperature drops to about several tens of degrees, for example, about 60 ° C., so that heat recovery from the exhaust gas Can be used effectively. In the above cycle, the flow rate, pressure,
By adjusting the droplet diameter, the output of the gas turbine can be adjusted.

The gas turbine cycle of the present invention described above and "FT4000 HAT WITH NATURAL GAS FUEL",
Compared with the first conventional technique disclosed in Japanese Patent Application Laid-Open No. 30811 and Japanese Patent Application Laid-Open No. H10-110628, the present embodiment adds post-cooling because water is added to compressed air by spraying water in a humidifying section. No compressor and humidification tower are required, the pressure loss of the compressed air is reduced, and the humidification unit can be provided at any position in the flow path from the compressor to the heat recovery unit. It is simplified and the manufacturing cost is reduced.

Further, since liquid-phase water is used for reheating the exhaust gas, it is not necessary to pass the exhaust gas before water recovery through an exhaust gas reheater. Because of the heat exchange, the heat transfer coefficient is increased and the exhaust gas reheater is downsized, so that the production cost and pressure loss are reduced. As a cause of obtaining the above-mentioned effect, heat exchange between water and gas is compared with heat exchange between gas and gas.
Since the heat transfer coefficient is good, the heat transfer area is small, and the heat exchanger may be downsized.

Next, in comparison with the second prior art disclosed in Japanese Patent Application Laid-Open No. Hei 8-232684, in this embodiment, the amount of water sprayed in the humidifying section is the amount that can be added to the compressed air as water vapor. Because it uses several times more than it, the problem of exhaust gas reheating when a water recovery device is added is solved in the best possible way.

In a high-humidity gas turbine cycle having a water recovery device, exhaust gas from which a part of exhaust heat is recovered by heating humidified compressed air is cooled to a relatively low temperature before entering the water recovery device. For example, performing sufficient heat recovery so as to be cooled to, for example, about 80 ° C. leads to improvement in thermal efficiency. For that purpose, it is necessary to perform the exhaust heat recovery using liquid water having an amount of about three times the amount of water vapor that can be added to the compressed air in the humidifying section. By spraying all the water in the heated liquid phase thus obtained in the humidifying section, excess water is generated in the humidifying section. Since the surplus water is deprived of heat as latent heat of evaporation, it becomes lower than the temperature before spraying, and has the effect of adding sensible heat to the compressed air. Thereby, the heat recovered in the heat recovery device is effectively added to the compressed air.

This surplus water has a temperature of 130 ° C., which is about 40 ° C. higher than the outlet water of the humidification tower when a post-cooler and a humidification tower are used.
And has a sufficient heat quantity to heat the exhaust gas at the outlet of the water recovery device to 90 ° C. or more. Further, by being cooled in the exhaust gas reheater and joining with the water recovered from the water recovery device, the surplus water becomes low-temperature water of about 60 ° C. which can be used again in the heat recovery device.

As described above, in the high-humidity gas turbine cycle for recovering water according to the present invention, sufficient heat recovery can be performed, pressure loss is low, and humidification that can obtain relatively high temperature excess water can be obtained. And a waste gas reheater using a liquid / gas heat exchange with a low pressure loss by using the excess water for the reheat of the exhaust gas, so that a very preferable system configuration is possible.

FIG. 2 shows another possible embodiment.
The difference from the embodiment of FIG. 1 lies in that an intercooler 44 is provided in the compression process to reduce the compression power, and that a part of the liquid-phase water 21a for heat recovery is diverted to separate the heat recovery device. 3
Is further heated to form steam 32 and mixed with liquid water 22a, 22b at a nozzle for spraying water in a humidifying section to utilize for promoting finer droplets and humidification. In addition, by utilizing the liquid-phase water 22b heated by the intercooler 43 to cool the compressed air 12a as spray water in the humidifying section 2 and incorporating it into the water circulation, effective use of heat can be achieved. I'm trying.

In the above cycle, in addition to the output control method shown in the cycle of FIG. 1, by adjusting the flow rate and pressure of water vapor sprayed together with liquid water in the humidifying section,
It is possible to regulate the output of the gas turbine. The above cycle is one embodiment, and the method of generating steam in the heat recovery device and the method of using the intercooler can be used separately. For example, the method of generating steam in the embodiment of FIG. It is also possible to add only

FIG. 3 shows an embodiment relating to a water circulation channel. In the example of FIG. 3, in addition to the circulation path of water shown in FIG. 1, a circulation path through which water 26 for reheating the exhaust gas on the lower temperature side passes is provided, and the final exhaust gas and the heat recovery device are provided. The function of adjusting the temperature of the exhaust gas at the outlet can be provided. The circulation flow path of the water 26 does not require a pushing power depending on the position setting of the device, and can generate circulation by natural convection.

FIG. 4 shows an embodiment of a water circulation channel which is considered to be advantageous for controlling the temperature condition of each component. A part of the water 22 heated in the heat recovery device 3 is diverted as water 27, and the excess water 2 obtained from the humidifying unit 2
A channel to be added to 3 is provided. In addition, a flow path for diverting a part or all of the water 27 as water 28 is provided, and a flow path for adding the exhaust gas to the reheated water after being cooled in the cooler 46 is provided. In addition, the structure is such that part of the surplus water 23 can pass through the flow path of the water 28. Further, a flow path is provided in which a part of the water immediately before entering the heat recovery device 3 is diverted as the water 29 and supplied to the water storage tank 45. In addition, a flow path from which the makeup water 30 can join the flow path of the water 28 from the water storage tank 45 is provided.

With the above flow path configuration, the final exhaust gas temperature,
It is possible to optimally control the outlet temperature of the heat recovery device and the flow rate of the circulating water. When the final exhaust gas temperature is low, the flow rate of the water 27 is increased to supply high-temperature water to the surplus water 23. When the final exhaust gas temperature is high, the flow path of the water 27 is closed, and the excess water 23
Is divided into a flow path of water 28 to reduce the amount of heated water.
When the heat recovery device outlet temperature is low, the flow rate of the circulating water is reduced by the water 29. If the heat recovery unit outlet temperature is high, make-up water 30
To increase the circulating water flow rate. When it is desired to adjust the heat recovery outlet temperature without changing the circulating water flow rate, a flow path from the water 27 to the water 28 is used as a bypass flow path, and excess heat is discarded to the cooler 46 as necessary.

Various embodiments are conceivable for the form of water spray in the humidifying section and the method of collecting surplus water. The spray form may be a forward direction, an opposite direction, an orthogonal direction, an oblique direction, etc., with respect to the air flow. Downflows, bent pipes, etc. are possible. Regarding the position of the spray port, various forms are conceivable, such as a method of providing the nozzle on the wall, a method of inserting a nozzle into the flow path, and the like. Whichever method is selected, it is desirable to select a combination that has good heat and mass exchange between water and air and has a small pressure loss. In addition, as a method of recovering surplus water, one that mainly uses gravity and one that uses a filter can be considered, but the arrangement connecting each element device does not become unnatural,
It is desirable to use a method with a small pressure loss.

FIGS. 5 to 8 show embodiments of the humidifying section. In the embodiment of FIG. 5, the compressed air 51 passes through a vertically descending flow path,
Hot water 52 is sprayed in the forward direction. Excess water 54 in the liquid phase is separated from air by the action of gravity in the lower part of the vertical descending flow path. The humidified air 53 once rises vertically to separate the droplets. It is considered that there is almost no pressure loss using this method.

In the embodiment shown in FIG. 6, the compressed air 51 passes through a vertically rising flow path, and hot water 52 is sprayed in the opposite direction. With this method, heat exchange and mass exchange are good.
In the embodiment of FIG. 7, the compressed air 51 is a horizontal flow, and hot water 52 is sprayed from a nozzle provided on a wall surface in a direction perpendicular to the horizontal flow. The humidified air 53 rises obliquely in the vertical direction, and separates the surplus water 54 by the action of gravity. It is considered that effective humidification can be achieved even in a channel having a large cross-sectional area by using this method.

In the embodiment shown in FIG. 8, the compressed air 51 is a horizontal flow, and hot water is sprayed in a direction opposite to the flow from a nozzle inserted into the flow path, and the droplets are pushed back into the flow and are sequentially moved with the air. It flows in the direction. Droplets and air are separated by the filter, and the humidified air 53 flows out in the horizontal direction as it is. Excess water 54 is collected at the lower part of the filter. With this method, humidification can be performed without changing the flow direction.

[0042]

As described above, according to the present invention, the simplicity of the gas turbine system utilizing high humidity for recovering water can be achieved, and the downsizing and low pressure loss of component devices can be promoted. Thus, it is possible to obtain a gas turbine plant of this type capable of reducing manufacturing costs and improving power generation output or power generation efficiency.

[Brief description of the drawings]

FIG. 1 is a system diagram showing one embodiment of a gas turbine plant of the present invention.

FIG. 2 is a system diagram showing another embodiment of the gas turbine plant of the present invention.

FIG. 3 is a system diagram showing one embodiment of a water flow path of the gas turbine plant of the present invention.

FIG. 4 is a system diagram showing another embodiment of the water flow path of the gas turbine plant of the present invention.

FIG. 5 is a vertical sectional side view showing one embodiment of the humidifier of the gas turbine plant of the present invention.

FIG. 6 is a vertical sectional side view showing another embodiment of the humidifier of the gas turbine plant of the present invention.

FIG. 7 is a vertical sectional side view showing another embodiment of the humidifier of the gas turbine plant of the present invention.

FIG. 8 is a vertical sectional side view showing another embodiment of the humidifier of the gas turbine plant of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Humidifier (humidifier), 3 ... Heat recovery device, 4 ... Combustor, 5 ... Gas turbine, 6 ... Water recovery device,
7 ... exhaust gas reheater, 8 ... generator, 41 ... water treatment device,
42 ... Pressure pump, 43 ... Pressure pump, 44 ... Intercooler, 45 ... Water storage tank, 46 ... Cooler, 51 ... Compressed air, 52 ... Hot water, 53 ... Wet air, 54 ... Excess water, 55
…filter.

Claims (12)

[Claims] 1. A humidifier for adding moisture to a combustion gas pressurized by a compressor, a heat recovery device for recovering thermal energy of exhaust gas from a gas turbine, and a water recovery for recovering moisture in the exhaust gas. In a gas turbine plant comprising a device and an exhaust gas reheating device for applying heat to the exhaust gas before releasing the exhaust gas to the atmosphere, the humidifier sprays heated liquid-phase water into the combustion gas. Spraying means for spraying, surplus water collecting means for collecting surplus water remaining in a liquid phase without evaporating sprayed water, and heating the water collected by the surplus water collecting means to the exhaust gas reheating device. A gas turbine plant provided with a supply means for supplying as source water. 2. A humidifier for adding moisture to a combustion gas pressurized by a compressor, a heat recovery device for recovering thermal energy of exhaust gas from a gas turbine, and a water recovery for recovering moisture in the exhaust gas. In a gas turbine plant provided with a device and an exhaust gas reheating device that applies heat to exhaust gas before releasing the exhaust gas to the atmosphere, supplying the plant with water heated by the heat recovery device to the humidifying device. Supply means, spray means for spraying the water supplied to the humidifier into the combustion gas, surplus water recovery means for recovering excess water remaining in the liquid phase without evaporation of the sprayed water, A gas turbine plant provided with supply means for supplying water recovered by the surplus water recovery means as heating source water of the exhaust gas reheating device. 3. The method according to claim 1, wherein the water after the exhaust gas is heated by the exhaust gas reheating device is used as a spray water when adding moisture to the combustion gas between the exhaust gas reheating device and the heat recovery device. 3. The gas turbine plant according to claim 2, further comprising a supply unit for supplying the recovery device. 4. The gas turbine plant according to claim 1, wherein the heat recovery device generates steam, and the steam is sprayed together with liquid-phase water by spraying means of the humidifier. 5. The gas turbine plant according to claim 1, wherein the spraying means is formed so as to supply water in excess of a limit amount that can be added as steam to the combustion gas. 6. A circulation path for water connected from the heat recovery device to the humidifier, from the humidifier to the exhaust gas reheater, from the exhaust gas reheater to the booster pump, and from the booster pump to the heat recovery device. The gas turbine plant according to claim 2, comprising: 7. The gas turbine plant according to claim 6, further comprising a flow passage between the flow passage connecting the exhaust gas reheater and the booster pump, where the water recovered from the water recovery device joins. 8. A humidifier for adding moisture to the combustion gas pressurized by the compressor, a heat recovery device for recovering thermal energy of exhaust gas from the gas turbine, and a water recovery for recovering moisture in the exhaust gas. In a method for operating a gas turbine plant comprising a device and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, when adding moisture to the combustion gas, the heat recovery device The heated water was supplied in the form of spray into the combustion gas, and the excess water remaining in the liquid phase without evaporation of the sprayed water was used as the heating source water of the exhaust gas reheating device. A method for operating a gas turbine plant, comprising: 9. The method according to claim 8, wherein when the hot water is supplied in the form of a spray into the combustion gas, water is supplied in excess of a limit amount that can be added as steam to the combustion gas. How to operate a gas turbine plant. 10. The water after the exhaust gas is heated by the exhaust gas reheating device is supplied to the heat recovery device as spray water when adding moisture to the combustion gas. Method of operating a gas turbine plant. 11. A humidifier for adding moisture to a combustion gas pressurized by a compressor, a heat recovery device for recovering thermal energy of exhaust gas from a gas turbine, and a water recovery for recovering moisture in the exhaust gas. In a control method of a gas turbine plant including a device and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, when adding moisture to the combustion gas, the heat recovery device The heated water is supplied in the form of a spray in the combustion gas, and the excess water remaining in a liquid phase without evaporation of the sprayed water is used as a heating source water of the exhaust gas reheating device, A method for controlling a gas turbine plant, wherein an output of a gas turbine is adjusted by adjusting a flow rate, a pressure, and a droplet diameter of liquid water to be sprayed in a humidifier. 12. A humidifier for adding moisture to a combustion gas pressurized by a compressor, a heat recovery device for recovering thermal energy of exhaust gas from a gas turbine, and a water recovery for recovering moisture in the exhaust gas. In a control method of a gas turbine plant including a device and an exhaust gas reheating device that applies heat to the exhaust gas before releasing the exhaust gas to the atmosphere, when adding moisture to the combustion gas, the heat recovery device The generated water vapor is supplied in the form of a spray into the combustion gas together with the water in the liquid phase, and excess water remaining in the liquid phase without evaporating the sprayed water is supplied to the heating source water of the exhaust gas reheating device. And controlling the output of the gas turbine by adjusting the flow rate and pressure of steam supplied to the humidifying device section. .