Gas Turbine Plant

Abstract

To provide an exhaust gas processing facility capable of further suppressing the generation of white smoke.SOLUTION: A gas turbine plant comprises: a gas turbine; a waste heat recovery boiler that generates steam by exchanging heat between exhaust gas from the gas turbine and water; an absorption tower that recovers carbon dioxide contained in the exhaust gas; an EGR line that bleeds a part of the exhaust gas and leads the same to the intake side of the gas turbine; an exhaust gas heater that uses steam extracted from the waste heat recovery boiler as a heat medium and exchanges heat between the heat medium and the exhaust gas to heat the exhaust gas that passes through the absorption tower; and an EGR heater that is provided on the EGR line and exchanges heat between the exhaust gas passing through the EGR line and the heat medium discharged from the exhaust gas heater to heat the exhaust gas flowing through the EGR line.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a gas turbine plant. To Regarding. [Background technology]

[0002] In a power generation plant that uses fossil fuels, for example, a gas turbine plant, exhaust gas is generated during operation of the gas turbine. This exhaust gas contains carbon dioxide. From the viewpoint of environmental conservation, there is a demand for a technology that can remove as much carbon dioxide as possible from the exhaust gas. For example, the method described in Patent Document 1 below is known as such a technology. In the method of Patent Document 1, at least a portion of the exhaust gas is brought into contact with an absorption liquid, and the absorption liquid adsorbs and removes carbon dioxide.

[0003] Depending on the operating conditions of a plant, exhaust gas may contain moisture (humidity). When this moisture condenses, white smoke is generated when the exhaust gas is discharged. White smoke not only mars the surrounding scenery, but also entrains trace amounts of nitrogen oxides remaining in the exhaust gas when the exhaust gas directly falls near the exhaust gas outlet, so there is a need to suppress this. Therefore, the technology described in Patent Document 1 below employs a method in which used absorption liquid is heated and regenerated using the heat of the exhaust gas, and the heat of the regenerated absorption liquid is used to heat the exhaust gas. This is said to evaporate the moisture in the exhaust gas and suppress the generation of white smoke. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-247932 Summary of the Invention [Problem to be solved by the invention]

[0005] However, because the heat of the regenerated absorption liquid is limited, there is a risk that the exhaust gas may not be heated sufficiently just by using the absorption liquid. Furthermore, to facilitate the capture of CO2 in exhaust gas, there is a technology that increases the CO2 concentration in the exhaust gas by recirculating the exhaust gas into the intake air. However, this also increases the moisture concentration in the exhaust gas, which is likely to result in white smoke if the exhaust gas is not heated sufficiently. Therefore, the device described in Patent Document 1 may still result in the generation of white smoke.

[0006] The present disclosure has been made to solve the above problems, and provides a method for further suppressing the generation of white smoke. Gas turbine plants The purpose is to provide. [Means for solving the problem]

[0007] In order to solve the above problems, a gas turbine plant according to the present disclosure includes a gas turbine, a heat recovery boiler that generates steam by exchanging heat between exhaust gas from the gas turbine and water, an exhaust line through which exhaust gas from the heat recovery boiler flows, and an exhaust gas heater that is provided in the exhaust line and uses steam extracted from the heat recovery boiler as a heat medium to exchange heat between the heat medium and exhaust gas that has passed through the absorption tower, thereby heating the exhaust gas, thereby suppressing the generation of white smoke from the exhaust gas discharged from the exhaust line; an auxiliary exhaust gas heater that heats the exhaust gas by exchanging heat between the exhaust gas that has passed through the exhaust gas heater and steam from the exhaust heat recovery boiler, the steam having a higher temperature than the steam that exchanges heat with the exhaust gas in the exhaust gas heater; Equipped with. In order to solve the above problems, another gas turbine plant according to the present disclosure includes a gas turbine, a heat recovery boiler that generates steam by exchanging heat between exhaust gas from the gas turbine and water, an exhaust line through which exhaust gas from the heat recovery boiler flows, and an exhaust gas heater that is provided in the exhaust line and uses steam extracted from the heat recovery boiler as a heat medium to exchange heat between the heat medium and the exhaust gas that has passed through the heat recovery boiler, thereby heating the exhaust gas. an auxiliary exhaust gas heater that heats the exhaust gas by exchanging heat between the exhaust gas that has passed through the exhaust gas heater and steam from the exhaust heat recovery boiler, the steam having a higher temperature than the steam that exchanges heat with the exhaust gas in the exhaust gas heater; An exhaust gas cooler that cools the exhaust gas by exchanging heat between the exhaust gas and a medium is not provided in the exhaust line downstream of the exhaust gas heater in the flow direction of the exhaust gas. [Effects of the Invention]

[0008] According to the gas turbine plant of the present disclosure, the generation of white smoke can be further suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram illustrating a configuration of a gas turbine plant according to a first embodiment of the present disclosure. [Figure 2] 1 is a diagram illustrating a configuration of a gas turbine plant according to a first embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment (Gas turbine plant configuration) A gas turbine plant 100 according to a first embodiment of the present disclosure will be described below with reference to Fig. 1. As shown in Fig. 1, the gas turbine plant 100 includes a gas turbine 1, a heat recovery boiler 2, a steam turbine 4, an exhaust gas treatment system 6, an EGR line L2, an EGR heater 7, and a control device 90.

[0011] (Gas turbine configuration) The gas turbine 1 has a compressor 11, a combustor 12, and a turbine 13. The compressor 11 compresses outside air introduced through an intake line La to generate high-pressure air. An outside air temperature measuring unit To that measures the temperature of the outside air and an outside air humidity measuring unit H that measures the humidity of the outside air are provided on the intake line La. In addition, an intake duct 11D and a filter F arranged in this intake duct 11D are provided on the intake side of the compressor 11.

[0012] The combustor 12 generates high-temperature, high-pressure combustion gas by mixing fuel with the high-pressure air generated by the compressor 11 and burning the mixture. The turbine 13 is driven by this combustion gas. The rotational energy of the turbine 13 is extracted from the shaft end and used, for example, to drive a generator G. The exhaust gas discharged from the turbine 13 is recovered by an exhaust line L1 and sent to the heat recovery boiler 2.

[0013] (Configuration of waste heat recovery boiler) The heat recovery boiler 2 generates superheated steam by exchanging heat between the exhaust gas flowing through the exhaust line L1 and water. This superheated steam is sent to the steam turbine 4 through the first line S1 and is used to drive the steam turbine 4. The rotational energy of the steam turbine 4 is used, for example, to drive a generator G. The steam discharged from the steam turbine 4 is recovered by the condenser 41. In the condenser 41, the steam is condensed to generate water by exchanging heat with a medium introduced from the outside. The water generated in the condenser 41 is supplied to the heat recovery boiler 2 through the fifth line S5.

[0014] An exhaust gas treatment system 6 is provided on the exhaust line L1 downstream of the heat recovery boiler 2. The exhaust gas treatment system 6 is provided to purify the exhaust gas flowing through the exhaust line L1 and release it into the outside air. The exhaust gas treatment system 6 has a carbon dioxide recovery unit 3 and an exhaust gas heater 5.

[0015] (Configuration of carbon dioxide capture device) The carbon dioxide capture unit 3 is a unit for capturing and removing carbon dioxide contained in the exhaust gas. The carbon dioxide capture unit 3 has a cooling tower 31 (quencher), an absorption tower 32, and a regeneration tower 33.

[0016] The cooling tower 31 is a facility for cooling the exhaust gas flowing through the exhaust line L1 prior to the recovery of carbon dioxide in the absorption tower 32, which will be described later. When the temperature of the exhaust gas flowing through the exhaust line L1 is about 90°C, the exhaust gas is cooled to about 30°C in the cooling tower 31. The exhaust gas cooled in the cooling tower 31 is sent to the absorption tower 32 through the exhaust line L1.

[0017] The absorber 32 has a cylindrical shape extending vertically, and an exhaust line L1 extending from the cooling tower 31 is connected to its lower part. Inside the absorber 32, an absorbing liquid capable of chemically bonding with carbon dioxide flows from top to bottom. Specific examples of such an absorbing liquid include aqueous solutions of amines such as monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), diisopropanolamine (DIPA), and methyldiethanolamine (MDEA), water-free organic solvents, mixtures thereof, and aqueous amino acid solutions. Absorbing liquids other than amines may also be used.

[0018] The exhaust gas that has flowed into the lower part of the absorption tower 32 rises inside the absorption tower 32 while coming into contact with the absorbing liquid flowing from above. At this time, the carbon dioxide contained in the exhaust gas is chemically absorbed by the absorbing liquid. The remaining exhaust gas from which the carbon dioxide has been removed flows again into the exhaust line L1 from the top of the absorption tower 32.

[0019] The absorption liquid that has absorbed carbon dioxide is sent to the regeneration tower 33 through the absorption liquid recovery line L4 connected to the bottom of the absorption tower 32. The regeneration tower 33 is a device for regenerating the absorption liquid that has absorbed carbon dioxide (separating the carbon dioxide). A third line S3, through which steam extracted from the above-mentioned heat recovery boiler 2 flows, is connected to the regeneration tower 33. A reboiler 34 is provided on the third line S3. Steam from the heat recovery boiler 2 is supplied to the reboiler 34 through the third line S3. In the reboiler 34, a portion of the water contained in the absorption liquid is heated by heat exchange with the steam, and becomes stripping steam. The stripping steam is sent to the regeneration tower 33 through the absorption liquid extraction line L7. In the regeneration tower 33, the stripping steam comes into contact with the absorption liquid before regeneration, which is supplied from the absorption liquid recovery line L4. As a result, carbon dioxide is released from the absorption liquid before regeneration, and the absorption liquid is regenerated (reduced to a state free of carbon dioxide). The carbon dioxide stripped from the absorbing liquid before regeneration is sent to a carbon dioxide compressor (not shown) from the regeneration tower 33. In addition, the steam discharged from the reboiler 34 is sent to the above-mentioned condenser 41 through the third line S3.

[0020] A portion of the regenerated absorption liquid (i.e., the components that did not become stripping steam) is sent to an absorption liquid supply line L5 connected to the bottom of the regenerator 33. A heat exchanger, a pump, and a cooler, all of which are not shown, are provided on the absorption liquid supply line L5. By driving the pump, the regenerated absorption liquid is supplied from the regenerator 33 to the heat exchanger. This causes heat exchange between the absorption liquid before regeneration and the absorption liquid after regeneration. Furthermore, the cooler appropriately cools the regenerated absorption liquid to a temperature suitable for absorbing carbon dioxide. The regenerated absorption liquid, now at a low temperature, is supplied to the top of the absorption tower 32.

[0021] (Configuration of exhaust gas heater) The exhaust gas heater 5 heats the exhaust gas discharged from the carbon dioxide recovery system 3 via the exhaust line L1 to suppress white smoke generation. The exhaust gas heater 5 is a heat exchanger. Steam (for example, 200°C to 230°C) extracted via the second line S2 branching from the third line S3 flows through the exhaust gas heater 5 as a heat medium. In other words, the exhaust gas heater 5 uses the steam extracted from the heat recovery boiler 2 as a heat medium. Note that "steam extracted from the heat recovery boiler 2" includes at least one of steam extracted directly from the heat recovery boiler 2 and steam extracted from the heat recovery boiler 2 after being used to drive the steam turbine 4. This causes heat exchange between the exhaust gas flowing through the exhaust line L1 and the steam, raising the temperature of the exhaust gas. At this time, at least a portion of the moisture (humidity) contained in the exhaust gas evaporates. The steam serving as a heat medium after passing through the exhaust gas heater 5 is sent via the second line S2 to the EGR heater 7 (described later) as a heat medium. The heat transfer medium may be in a liquid phase (water) or a gas phase (steam).

[0022] The EGR line L2 extracts at least a portion of the exhaust gas that has passed through the cooling tower 31 of the carbon dioxide recovery unit 3 and guides it to the intake side (compressor 11) of the gas turbine 1. More specifically, one end of the EGR line L2 is provided upstream of the filter F in the intake duct 11D (i.e., on the side that is in contact with the outside air). An EGR heater 7 and an exhaust gas temperature measurement unit Te are provided on the EGR line L2, in this order, from the cooling tower 31 side toward the gas turbine 1 side. The EGR heater 7 is a heat exchanger. In the EGR heater 7, heat is exchanged between the heat medium guided from the exhaust gas heater 5 through the second line S2 and the exhaust gas. As a result, the exhaust gas that has passed through the EGR heater 7 is heated. As an example, when the temperature of the exhaust gas supplied from the cooling tower 31 is about 30°C, it is desirable that the temperature of the exhaust gas after passing through the EGR heater 7 be about 40°C.

[0023] The heat transfer medium that has passed through the EGR heater 7 is guided to the condenser 41 through the second line S2. A valve device V (supply amount adjustment unit) is provided on the second line S2 between the EGR heater 7 and the condenser 41. By changing the opening degree of this valve device V, the flow rate of the heat transfer medium flowing through the second line S2 changes. In other words, the valve device V is a flow rate adjustment valve. The opening degree of the valve device V is determined and adjusted by the control device 90 based on the temperature of the exhaust gas measured by the exhaust gas temperature measurement unit Te, the humidity of the exhaust gas measured by the outside air temperature measurement unit To, and the humidity of the outside air measured by the outside air humidity measurement unit H.

[0024] (Action and effect) According to the above-described configuration, the exhaust gas passing through the absorption tower 32 is heated by the exhaust gas heater 5. This evaporates moisture contained in the exhaust gas, further reducing the possibility of the exhaust gas turning into white smoke when released to the outside. Furthermore, in the above-described configuration, a portion of the exhaust gas discharged from the cooling tower 31 is guided (recirculated) to the intake side of the gas turbine 1 through the EGR line L2. If moisture is contained in the exhaust gas, moisture may adhere to the filter F provided in the intake duct 11D of the compressor 11, increasing the intake resistance. Furthermore, if the moisture turns into water droplets and impinges on the rotor blades of the compressor 11, erosion may occur. Furthermore, since not only CO2 but also moisture is concentrated in the EGR line L2, the possibility of white smoke generation tends to increase. In the above-described configuration, the exhaust gas flowing through the EGR line L2 is heated by the EGR heater 7. This reduces the humidity of the exhaust gas, thereby suppressing moisture adhesion to the filter F. As a result, an increase in the intake resistance can be suppressed.

[0025] According to the above configuration, the amount of heat medium supplied to the EGR heater 7 is adjusted based on the temperature of the exhaust gas flowing through the EGR line L2. This makes it possible to change the amount of heat of the exhaust gas by the EGR heater 7. For example, if the temperature of the exhaust gas supplied to the gas turbine 1 is too high, the opening of the valve device V, which serves as a supply amount adjustment unit, is reduced to reduce the amount of heat medium, thereby changing the temperature in a lower direction. This reduces the amount of heat medium used and improves plant efficiency. Conversely, if the temperature of the exhaust gas is too low, the amount of heat medium is increased to change the temperature in a higher direction. As a result, the temperature of the exhaust gas supplied to the gas turbine 1 is optimized, and it is possible to prevent moisture saturation in the mixed gas of outside air and exhaust gas.

[0026] According to the above configuration, the amount of heat medium supplied to the EGR heater 7 is adjusted based on not only the temperature of the exhaust gas flowing through the EGR line L2 but also the temperature of the outside air supplied to the gas turbine 1. For example, when the temperature of the outside air is low, the opening of the valve device V, which serves as a supply amount adjustment unit, is increased to increase the amount of heat medium and raise the temperature of the exhaust gas. As a result, the temperature of the exhaust gas supplied to the gas turbine 1 is optimized, and the temperature of the mixed gas of the outside air and the exhaust gas exceeds the dew point, preventing moisture saturation.

[0027] According to the above configuration, the amount of heat medium supplied to the EGR heater 7 is adjusted based on the temperature of the exhaust gas flowing through the EGR line L2 and the temperature of the outside air, as well as the humidity of the outside air. For example, when the humidity of the outside air is excessively high, the amount of heat medium supplied to the EGR heater 7 is increased to raise the temperature of the exhaust gas. On the other hand, when the humidity of the outside air is excessively low, the amount of heat medium supplied to the EGR heater 7 is reduced to lower the temperature of the exhaust gas. As a result, the temperature and humidity of the exhaust gas supplied to the gas turbine 1 are optimized, and it is possible to prevent moisture saturation in the mixed gas of the outside air and the exhaust gas.

[0028] The first embodiment of the present disclosure has been described above. It should be noted that various changes and modifications can be made to the above configuration without departing from the spirit and scope of the present disclosure. For example, in the first embodiment, an example has been described in which an exhaust gas temperature measuring unit Te and an outside air humidity measuring unit H are provided on the EGR line, and an outside air temperature measuring unit To is provided on the intake line La. However, it is also possible to adopt a configuration in which the outside air temperature measuring unit To is not provided, or a configuration in which the outside air humidity measuring unit H is not provided. In other words, it is possible to adopt a configuration in which only the exhaust gas temperature measuring unit Te is provided.

[0029] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to FIG. 2. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the configuration of the steam turbine 4 is different from that in the first embodiment. Furthermore, in this embodiment, in addition to the exhaust gas heater 5 described in the first embodiment, an auxiliary exhaust gas heater 5B is further provided.

[0030] The steam turbine 4 has a high-pressure steam turbine 4H and a low-pressure steam turbine 4L. The low-pressure steam turbine 4L and the high-pressure steam turbine 4H may be connected coaxially or may be independent of each other. The high-pressure steam turbine 4H is driven by steam guided from the heat recovery boiler 2 through a first line S1. The steam that has passed through the high-pressure steam turbine 4H is guided to the low-pressure steam turbine 4L and drives the low-pressure steam turbine 4L. The steam that has passed through the low-pressure steam turbine 4L is sent to a condenser 41.

[0031] A sixth line S6 is connected to an intermediate stage of the high-pressure steam turbine 4H. High-temperature steam (for example, 250°C to 350°C) extracted by the sixth line S6 is sent as a heat medium to an auxiliary exhaust gas heater 5B, which will be described later. Note that the steam turbine 4 may be configured to have only one turbine. In this case, it is desirable that the sixth line S6 be connected to a high-pressure side stage of the steam turbine 4.

[0032] The auxiliary exhaust gas heater 5B is provided in the exhaust line L1 downstream of the exhaust gas heater 5. The auxiliary exhaust gas heater 5B is a heat exchanger, and performs heat exchange between steam extracted from the high-pressure steam turbine 4H and the exhaust gas flowing through the exhaust line L1.

[0033] In addition, in this embodiment, the steam as a heat medium that has passed through the auxiliary exhaust gas heater 5B can be guided to the second line S2 through the auxiliary line S7.

[0034] According to the above configuration, the exhaust gas that has passed through the exhaust gas heater 5 is further heated by the auxiliary exhaust gas heater 5B. This further reduces the moisture content in the exhaust gas, further reducing the possibility of white smoke generation.

[0035] The second embodiment of the present disclosure has been described above. Note that various changes and modifications can be made to the above configuration without departing from the spirit and scope of the present disclosure.

[0036] For example, as a modified example common to all the embodiments, it is possible to employ a configuration in which only steam extracted from the steam turbine 4 is supplied to the EGR heater 7 as the heat medium. Also, it is possible to use only steam extracted from the heat recovery boiler 2 as the heat medium for the EGR heater 7. Furthermore, it is also possible to use both the steam extracted from the steam turbine 4 and the steam extracted from the heat recovery boiler 2. In this way, three types of modes are conceivable for the heat medium for the EGR heater 7. The exhaust gas heater 5 can also use only steam extracted from the steam turbine 4 as the heat medium. Furthermore, as in the above embodiment, it is also possible to use only the heat recovery boiler 2 as the heat medium for the exhaust gas heater 5. It is also possible to use a combination of steam extracted from the heat recovery boiler 2 and steam extracted from the steam turbine 4 as the heat medium for the exhaust gas heater 5. As described above, three types of heat medium are possible for the exhaust gas heater 5. In other words, a total of nine types of configurations are possible in combination with the heat medium of the EGR heater 7 described above. It is possible to appropriately select a suitable configuration from these nine types of combinations depending on the design and specifications.

[0037] <Additional Notes> The gas turbine plant 100 described in each embodiment can be understood, for example, as follows.

[0038] (1) A gas turbine plant 100 according to a first aspect includes a gas turbine 1, a heat recovery boiler 2 that generates steam by exchanging heat between exhaust gas from the gas turbine 1 and water, an absorption tower 32 that recovers carbon dioxide contained in the exhaust gas, an EGR line L2 that extracts a portion of the exhaust gas and leads it to the intake side of the gas turbine 1, an exhaust gas heater 5 that uses steam extracted from the heat recovery boiler 2 as a heat medium to heat the exhaust gas that has passed through the absorption tower 32, and an EGR heater 7 that is provided on the EGR line L2 and heats the exhaust gas flowing through the EGR line L2 by exchanging heat between the exhaust gas flowing through the EGR line L2 and the heat medium discharged from the exhaust gas heater 5.

[0039] According to the above configuration, the exhaust gas that has passed through the absorption tower 32 is heated by the exhaust gas heater 5. This causes moisture contained in the exhaust gas to evaporate, thereby reducing the possibility that the exhaust gas will turn into white smoke when it is released to the outside.

[0040] (2) The gas turbine plant 100 according to the second aspect further includes a quencher that cools the exhaust gas discharged from the heat recovery boiler 2, and the EGR line L2 extracts a portion of the exhaust gas discharged from the quencher and leads it to the intake side of the gas turbine 1.

[0041] In the above configuration, a portion of the exhaust gas discharged from the quencher is guided (recirculated) through the EGR line L2 to the intake side of the gas turbine 1. If the exhaust gas contains moisture, the moisture will adhere to the filter F provided in the intake duct 11D of the compressor 11, increasing the intake resistance. However, in the above configuration, the exhaust gas flowing through the EGR line L2 is heated by the EGR heater 7. This reduces the humidity contained in the exhaust gas, preventing moisture from saturating in the mixed gas of outside air and exhaust gas.

[0042] (3) The gas turbine plant 100 according to the third aspect further includes an exhaust gas temperature measuring unit Te that is provided on the EGR line L2 closer to the intake side of the gas turbine than the EGR heater 7 and that measures the temperature of the exhaust gas flowing through the EGR line L2, and a supply amount adjusting unit (valve device V) that adjusts the amount of the heat medium supplied to the EGR heater 7 based on the temperature of the exhaust gas.

[0043] According to the above configuration, the amount of heat medium supplied to the EGR heater 7 is adjusted based on the temperature of the exhaust gas flowing through the EGR line L2. This makes it possible to change the amount of heat of the exhaust gas by the EGR heater 7. For example, if the temperature of the exhaust gas supplied to the gas turbine 1 is too high, the supply amount adjustment unit can reduce the amount of heat medium, thereby changing the temperature in a lower direction. Conversely, if the temperature of the exhaust gas is too low, the supply amount adjustment unit can increase the amount of heat medium, thereby changing the temperature in a higher direction. As a result, the temperature of the exhaust gas supplied to the gas turbine 1 is optimized, and it is possible to prevent moisture saturation in the mixed gas of outside air and exhaust gas.

[0044] (4) The gas turbine plant 100 according to the fourth aspect further includes an outside air temperature measuring unit To that measures the temperature of the outside air drawn into the gas turbine 1, and the supply amount adjusting unit (valve device V) adjusts the amount of the heat medium supplied to the EGR heater 7 based on the temperature of the exhaust gas and the temperature of the outside air.

[0045] According to the above configuration, the amount of heat medium supplied to the EGR heater 7 is adjusted based on not only the temperature of the exhaust gas flowing through the EGR line L2 but also the temperature of the outside air supplied to the gas turbine 1. For example, when the temperature of the outside air is lower than the temperature of the exhaust gas, the supply amount adjustment unit reduces the amount of heat medium, thereby bringing the temperature of the exhaust gas closer to the temperature of the outside air. As a result, the temperature of the exhaust gas supplied to the gas turbine 1 is optimized, and it is possible to prevent moisture saturation in the mixed gas of the outside air and the exhaust gas.

[0046] (5) The gas turbine plant 100 according to the fifth aspect further includes an outside air humidity measuring unit H that measures the humidity of the outside air supplied to the gas turbine, and the supply amount adjusting unit adjusts the amount of the heat medium supplied to the EGR heater based on the temperature of the exhaust gas, the temperature of the outside air, and the humidity of the outside air.

[0047] According to the above configuration, the amount of heat medium supplied to the EGR heater 7 is adjusted based on the temperature of the exhaust gas flowing through the EGR line L2, the temperature of the outside air, and also the humidity of the outside air. As a result, the temperature and humidity of the exhaust gas supplied to the gas turbine 1 are optimized, and it is possible to prevent the moisture content in the mixed gas of the outside air and the exhaust gas from becoming saturated.

[0048] (6) The gas turbine plant 100 according to the sixth aspect further includes a steam turbine 4 driven by steam generated in the heat recovery boiler 2, and an auxiliary exhaust gas heater 5B that heats the exhaust gas by exchanging heat between the steam extracted from the steam turbine 4 and the exhaust gas that has passed through the absorption tower 32.

[0049] According to the above configuration, the exhaust gas that has passed through the exhaust gas heater 5 is further heated by the auxiliary exhaust gas heater 5B. This further reduces the moisture content in the exhaust gas, further reducing the possibility of white smoke generation.

[0050] (7) The gas turbine plant 100 according to the seventh aspect further includes a high-pressure steam turbine 4H driven by steam generated in the heat recovery boiler 2, a low-pressure steam turbine 4L driven by steam discharged from the high-pressure steam turbine 4H, and an auxiliary exhaust gas heater 5B provided downstream of the exhaust gas heater 5 to further heat the exhaust gas by exchanging heat between the steam extracted from the high-pressure steam turbine 4H and the exhaust gas that has passed through the exhaust gas heater 5.

[0051] According to the above configuration, the exhaust gas that has passed through the exhaust gas heater 5 is further heated by the auxiliary exhaust gas heater 5B. This further reduces the moisture content in the exhaust gas, further reducing the possibility of white smoke generation. [Explanation of symbols]

[0052] 100 Gas Turbine Plant 1. Gas turbine 2. Waste heat recovery boiler 3 Carbon dioxide capture equipment 4. Steam turbine 4H high pressure steam turbine 4L low pressure steam turbine 5 Exhaust gas heater 5B Auxiliary exhaust gas heater 6. Exhaust gas treatment equipment 7 EGR heater 11 Compressor 11D Intake duct 12 Combustor 13 Turbine 31 Cooling Tower 32 Absorption tower 33 Regeneration Tower 34 Reboiler 90 Control device F Filter G Generator H Outdoor air humidity measurement section P Water supply pump Te Exhaust gas temperature measurement unit To Outside air temperature measurement section L1 Exhaust line L2 EGR line L4 Absorbent recovery line L5 Absorbent supply line L6 cooling line L7 Absorbent Extraction Line S1 First Line S2 Second Line S3 Third Line S4 Fourth Line S5 Fifth Line S6 Sixth Line V-valve device (supply volume adjustment section)

Claims

1. A gas turbine, a heat recovery boiler that generates steam by exchanging heat between the exhaust gas of the gas turbine and water; an exhaust line through which exhaust gas from the heat recovery boiler flows; an exhaust gas heater that is provided in the exhaust line and that uses steam extracted from the heat recovery boiler as a heat medium to exchange heat between the heat medium and the exhaust gas that has passed through the heat recovery boiler, thereby heating the exhaust gas and suppressing the generation of white smoke from the exhaust gas discharged from the exhaust line; an auxiliary exhaust gas heater that heats the exhaust gas by exchanging heat between the exhaust gas that has passed through the exhaust gas heater and steam from the exhaust heat recovery boiler, the steam having a higher temperature than the steam that exchanges heat with the exhaust gas in the exhaust gas heater; A gas turbine plant comprising:

2. A gas turbine, a heat recovery boiler that generates steam by exchanging heat between the exhaust gas of the gas turbine and water; an exhaust line through which exhaust gas from the heat recovery boiler flows; an exhaust gas heater that is provided in the exhaust line and that uses steam extracted from the heat recovery boiler as a heat medium to exchange heat between the heat medium and the exhaust gas that has passed through the heat recovery boiler, thereby heating the exhaust gas; an auxiliary exhaust gas heater that heats the exhaust gas by exchanging heat between the exhaust gas that has passed through the exhaust gas heater and steam from the exhaust heat recovery boiler, the steam having a higher temperature than the steam that exchanges heat with the exhaust gas in the exhaust gas heater; Equipped with an exhaust gas cooler that cools the exhaust gas by exchanging heat between the exhaust gas and a medium is not provided in the exhaust line downstream of the exhaust gas heater in the flow direction of the exhaust gas; Gas turbine plant.

3. an absorption tower that absorbs carbon dioxide contained in the exhaust gas discharged from the heat recovery boiler; 3. The gas turbine plant according to claim 1, wherein the exhaust gas heater heats the exhaust gas by exchanging heat between the exhaust gas that has passed through the heat recovery boiler and the absorption tower and the heat medium.

4. a steam turbine that can be driven by steam generated in the heat recovery boiler, 3. The gas turbine plant according to claim 1, wherein the auxiliary exhaust gas heater exchanges heat between steam extracted from the steam turbine and the exhaust gas that has passed through the exhaust gas heater.

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