Gas turbine power plant, and method of operating same

Abstract

This gas turbine power plant comprises: a gas turbine; a gas turbine generator; an air bleed line capable of bleeding a portion of compressed air generated by a compressor of the gas turbine from the gas turbine as bleed air; an auxiliary turbine that is connected to the air bleed line and can be driven by the bleed air flowing through the air bleed line; an air bleed valve provided in the air bleed line; an auxiliary generator capable of generating electricity by being driven by the auxiliary turbine; and a storage battery capable of storing the electricity generated by the auxiliary generator.

Description

Gas turbine power plant and its operating method

[0001] This application claims priority to Japanese Patent Application No. 2023-108231, filed on June 30, 2023, the contents of which are incorporated herein by reference.

[0002] A gas turbine includes a compressor that compresses air, a combustor that burns fuel in the air compressed by the compressor to generate combustion gas, and a turbine that is driven by the combustion gas. The rotor of the gas turbine is connected to the rotor of a generator.

[0003] Patent Document 1 below discloses a technique for dealing with a situation where the load on the power grid decreases and the external output required decreases. In this technique, when the external output required decreases, a portion of the air compressed by the compressor is bled from the gas turbine to suppress the output of the gas turbine. The high-pressure air bled from the gas turbine is stored in an air tank and used as needed.

[0004] Japanese Patent Application Publication No. 09-287482

[0005] In recent years, the number of power generation facilities using renewable energy such as solar and wind power has been increasing. However, such power generation facilities using renewable energy have large fluctuations in the amount of power generated. Therefore, gas turbine power generation plants are required to flexibly respond to fluctuations in external output requirements in order to compensate for the fluctuations in the amount of power generated by power generation facilities using renewable energy.

[0006] Therefore, an object of the present disclosure is to provide a technique that can flexibly respond to fluctuations in externally required output.

[0007] a gas turbine power plant as one aspect for achieving the above-mentioned object, the gas turbine power plant comprising: a gas turbine having a compressor capable of compressing air; a combustor capable of burning fuel in the compressed air compressed by the compressor to generate combustion gas; and a turbine capable of driving the combustion gas; a gas turbine generator connected to the gas turbine and capable of generating electricity by driving the turbine; an extraction line capable of extracting from the gas turbine a portion of the compressed air generated by the compressor as extraction air; an auxiliary turbine connected to the extraction line and capable of driving the extraction air that has flowed through the extraction line; an extraction valve provided in the extraction line; an auxiliary generator connected to the auxiliary turbine and capable of generating electricity by driving the auxiliary turbine; a storage battery capable of storing electricity generated by the auxiliary generator; a gas turbine power line electrically connecting the gas turbine generator to an external power system; and a storage battery power line electrically connecting the storage battery to the external power system.

[0008] In this aspect, when the actual output of the gas turbine falls to or below a predetermined bleed output that is smaller than the rated output, the bleed valve is opened, and a portion of the compressed air generated by the compressor is bled outside the gas turbine as bleed air. Therefore, in this aspect, when the actual output of the gas turbine falls from the rated output to or below the bleed output and the flow rate of fuel supplied to the combustor decreases accordingly, the flow rate of compressed air supplied to the combustor also decreases, making it possible to suppress deterioration in fuel combustibility. Therefore, in this aspect, it is possible to deal with a case where the required output is equal to or less than the bleed output and the actual output is set to or below the bleed output while suppressing deterioration in fuel combustibility.

[0009] In this embodiment, the auxiliary turbine is driven by the extracted air, and the auxiliary generator generates electricity by this drive. The electricity generated by the auxiliary generator is stored in the storage battery.

[0010] In this aspect, the external power system can be supplied with power from the storage battery in addition to power from the gas turbine generator, so this aspect can handle situations where the required output from the outside is greater than the rated output, or where the gas turbine generator alone cannot handle the situation.

[0011] Therefore, in this embodiment, it is possible to flexibly respond to fluctuations in the required output from the outside.

[0012] A method for operating a gas turbine power plant as one aspect for achieving the above-mentioned object is applied to the following gas turbine power plant. The gas turbine power plant includes a gas turbine having a compressor capable of compressing air, a combustor capable of burning fuel in the compressed air compressed by the compressor to generate combustion gas, and a turbine driven by the combustion gas; and a gas turbine generator connected to the gas turbine, generating electricity by driving the turbine and transmitting the electricity to an external power system. The method for operating a gas turbine power plant according to this aspect includes, when an actual output of the gas turbine falls below a predetermined extraction output that is lower than the rated output of the gas turbine, a bleeding step of bleeding part of the compressed air generated by the compressor outside the gas turbine as extraction air to reduce the flow rate of the compressed air flowing into the combustor, and a charging step of storing electricity in a storage battery that can be discharged to the external power system. In the charging step, an auxiliary turbine is driven by the extraction air, an auxiliary generator is driven to generate electricity by driving the auxiliary turbine, and the electricity generated by the auxiliary generator is stored in the storage battery.

[0013] In this aspect, similar to the gas turbine power plant in the above aspect, it is possible to flexibly respond to fluctuations in the required output from the outside.

[0014] According to one aspect of the present disclosure, it is possible to flexibly respond to fluctuations in externally required output.

[0015] Fig. 1 is a system diagram of a gas turbine power plant in a first embodiment according to the present disclosure; Fig. 2 is a graph showing the relationship between actual output and IGV opening of the gas turbine power plant in the first embodiment according to the present disclosure; Fig. 3 is a flowchart showing the operation of the gas turbine power plant in the first embodiment according to the present disclosure; Fig. 4 is a system diagram of a gas turbine power plant in a second embodiment according to the present disclosure; Fig. 5 is a flowchart showing the operation of the gas turbine power plant in the second embodiment according to the present disclosure;

[0016] Hereinafter, various embodiments and modifications of the gas turbine power plant according to the present disclosure will be described with reference to the drawings.

[0017] First Embodiment of Gas Turbine Power Plant Hereinafter, a first embodiment of a gas turbine power plant according to the present disclosure will be described with reference to FIGS. 1 to 3. FIG.

[0018] As shown in FIG. 1 , the gas turbine power plant in this embodiment includes a gas turbine 1, a waste heat utilization facility 20 that utilizes the heat of exhaust gas discharged from the gas turbine 1, a gas turbine generator 6 that generates electricity by driving the gas turbine 1, an air extraction facility 30 that can extract part of the air inside the gas turbine 1 to the outside, an auxiliary power generation facility 40, a power system facility 50, and a control device 100.

[0019] The gas turbine 1 includes a compressor 10 capable of compressing air A, a combustor 15 capable of generating combustion gas by burning fuel F in the compressed air compressed by the compressor 10, a fuel valve 5, a turbine 16 capable of being driven by high-temperature, high-pressure combustion gas, and an intermediate casing 3.

[0020] The compressor 10 includes a compressor rotor 11 that rotates about a rotor axis Ar, a compressor casing 12 that covers the compressor rotor 11, and an intake air amount regulator 13. Here, the direction in which the rotor axis Ar extends is defined as an axial direction Da, and one side of the axial direction Da is defined as an axial upstream side Dau, and the other side is defined as an axial downstream side Dad.

[0021] The compressor rotor 11 has a compressor rotor shaft 11s extending in the axial direction Da centered on the rotor axis Ar, and a plurality of rotor blade rows 11b fixed to the compressor rotor shaft 11s. The plurality of rotor blade rows 11b are aligned in the axial direction Da. Each of the plurality of rotor blade rows 11b has a plurality of rotor blades aligned in the circumferential direction about the rotor axis Ar. The intake air regulator 13 has a plurality of inlet guide vanes (IGVs) 13v arranged within the compressor casing 12 on the axial upstream side Dau of the plurality of rotor blade rows 11b, and a driver 13d that can change the orientation of each inlet guide vane 13v.

[0022] The turbine 16 is disposed on the axial downstream side Dad of the compressor 10. The turbine 16 has a turbine rotor 17 that rotates about a rotor axis Ar by combustion gas from the combustor 15, and a turbine casing 18 that covers the turbine rotor 17.

[0023] The turbine rotor 17 has a turbine rotor shaft 17s that extends in the axial direction Da around the rotor axis Ar, and a plurality of rotor blade rows 17b fixed to the turbine rotor shaft 17s. The rotor blade rows 17b are aligned in the axial direction Da. Each of the rotor blade rows 17b has a plurality of rotor blades aligned in the circumferential direction with respect to the rotor axis Ar.

[0024] The turbine rotor 17 and the compressor rotor 11 are connected to each other so as to be rotatable together about the same rotor axis Ar, thereby forming a gas turbine rotor 2. To this gas turbine rotor 2, a rotor of a gas turbine generator 6 is connected.

[0025] The intermediate casing 3 is disposed between the compressor casing 12 and the turbine casing 18 in the axial direction Da, and connects the compressor casing 12 and the turbine casing 18. Compressed air discharged from the compressor 10 flows into the intermediate casing 3. The combustor 15 is fixed to the intermediate casing 3. A fuel line 4 is connected to the combustor 15. The fuel line 4 is provided with the aforementioned fuel valve 5 that adjusts the flow rate of the fuel F flowing through the fuel line 4.

[0026] The waste heat utilization facility 20 includes a heat recovery boiler 21, a chimney 22, a steam turbine 23 driven by steam from the heat recovery boiler 21, a main steam line 24 capable of guiding steam generated in the heat recovery boiler 21 to the steam turbine 23, a condenser 25 capable of converting steam exhausted from the steam turbine 23 back into water, a feedwater line 26 capable of guiding water in the condenser 25 to the heat recovery boiler 21, and a feedwater pump 27 provided in the feedwater line 26. A driven object that can be rotated by the rotation of the rotor is connected to the rotor of the steam turbine 23. Examples of the driven object include the rotor of the gas turbine generator 6, the rotor of a steam turbine generator independent of the gas turbine generator 6, and the impeller of a pump.

[0027] The heat recovery boiler 21 can generate steam by evaporating water using the heat of exhaust gas, which is combustion gas discharged from the turbine 16. The heat recovery boiler 21 has a duct 21d connected to the turbine casing 18 and a heat transfer tube 21t arranged in the duct 21d. Exhaust gas from the turbine 16 flows through the duct 21d. Liquid water or gaseous water flows through the heat transfer tube 21t. One end of the heat transfer tube 21t forms a water inlet and is connected to a water supply line 26. The other end of the heat transfer tube 21t forms a steam outlet and is connected to the main steam line 24. The chimney 22 is connected to the duct 21d of the heat recovery boiler 21.

[0028] The extraction equipment 30 includes an extraction line 31 that can extract part of the compressed air generated by the compressor 10 as extraction air from the gas turbine 1, an extraction valve 32, and an auxiliary turbine 33 that can be driven by the extraction air that has flowed through the extraction line 31.

[0029] The auxiliary turbine 33 has a rotatable auxiliary turbine rotor 34 and an auxiliary turbine casing 35 that covers the auxiliary turbine rotor 34. One end of the bleed line 31 is connected to the intermediate casing 3 of the gas turbine 1. The other end of the bleed line 31 is connected to the auxiliary turbine casing 35. Thus, part of the compressed air that has flowed into the intermediate casing 3 via the bleed line 31 can flow into the auxiliary turbine casing 35 as bleed air. The auxiliary turbine rotor 34 rotates by the bleed air that has flowed into the auxiliary turbine casing 35. A bleed valve 32 is provided in the bleed line 31. This bleed valve 32 can adjust the flow rate of the bleed air flowing through the bleed line 31.

[0030] The auxiliary power generating facility 40 includes an auxiliary generator 41, a storage battery 42, an auxiliary generator power line 43, an AC / DC converter 44 capable of converting AC power into DC power, and a DC / AC converter 45 capable of converting DC power into AC power. The rotor of the auxiliary generator 41 is connected to the auxiliary turbine rotor 34. Therefore, the auxiliary generator 41 generates power by driving the auxiliary turbine 33. The auxiliary generator power line 43 electrically connects the auxiliary generator 41 and the storage battery 42. The AC / DC converter 44 is provided in the auxiliary generator power line 43. Therefore, the AC power generated by the auxiliary generator 41 is converted into DC power by the AC / DC converter 44, and the electrical energy of this AC power is then stored in the storage battery 42.

[0031] The power system equipment 50 includes a gas turbine power line 51 electrically connecting the gas turbine generator 6 and an external power system 59, a transformer 52 provided on the gas turbine power line 51, an output meter 53, a storage battery power line 54 electrically connecting the storage battery 42 and the external power system 59, a transformer 55 provided on the storage battery power line 54, and a switch 56. The output meter 53 is capable of detecting the actual power generation amount of the gas turbine generator 6, in other words, the actual output that is the actual output of the gas turbine 1. The switch 56 is provided in the storage battery power line 54 between the transformer 55 and the storage battery 42. The switch 56 can be switched between an ON state in which the storage battery 42 and the external power system 59 are electrically connected and an OFF state in which the storage battery 42 and the external power system 59 are not electrically connected. The DC / AC converter 45 described above is provided in the storage battery power line 54 between the switch 56 and the storage battery 42.

[0032] The control device 100 has a fuel controller 101 capable of controlling the opening of the fuel valve 5, an IGV controller 102 capable of controlling the IGV opening θ, which is the opening of the inlet guide vane 13v of the compressor 10, a bleed controller 103 capable of controlling the opening of the bleed valve 32, and an opening / closing controller 104 capable of controlling the state of the switch 56.

[0033] The fuel controller 101 receives a required output PWc externally requested of the gas turbine 1 and an actual output PWr detected by the power meter 53, determines the opening degree of the fuel valve 5 according to the deviation between the required output PWc and the actual output PWr, and instructs the fuel valve 5 to this opening degree. A change in the flow rate of fuel supplied to the combustor 15 is positively correlated with a change in the opening degree of the fuel valve 5. Furthermore, a change in the opening degree of the fuel valve 5 is positively correlated with a change in the required output PWc. Therefore, a change in the flow rate of fuel supplied to the combustor 15 is positively correlated with a change in the required output PWc. Therefore, as the required output PWc increases, the flow rate of fuel supplied to the combustor 15 increases, and as the required output PWc decreases, the flow rate of fuel supplied to the combustor 15 decreases.

[0034] The IGV controller 102 receives the actual output PWr detected by the power meter 53, determines the IGV opening θ according to this actual output PWr, and indicates this IGV opening θ to the intake air regulator 13. As shown in FIG. 2 , when the actual output PWr is between the intermediate output PWmid and the rated output PWrad, changes in the IGV opening θ have a positive correlation with changes in the actual output PWr. Therefore, as the actual output PWr increases, the IGV opening θ also increases, and as the actual output PWr decreases, the IGV opening θ also decreases. When the actual output PWr is the intermediate output PWmid, the IGV opening θ is at its minimum opening θmin, and when the actual output PWr is the rated output PWrad, the IGV opening θ is at its maximum opening θmax.

[0035] The bleed air controller 103 receives the actual output PWr detected by the power meter 53 and instructs the bleed air valve 32 to open or close depending on whether the actual output PWr satisfies the bleed air condition. Here, the bleed air condition is that the actual output PWr detected by the power meter 53 is equal to or less than a predetermined bleed air output PWbl. Here, the bleed air output PWbl is a pressure equal to or less than the intermediate output PWmid, as shown in FIG. 2 . If the bleed air controller 103 determines that the actual output PWr detected by the power meter 53 satisfies the bleed air condition, in other words, that the actual output PWr is equal to or less than the bleed air output PWbl, the bleed air controller instructs the bleed air valve 32 to open. On the other hand, if the bleed air controller 103 determines that the actual output PWr detected by the power meter 53 does not satisfy the bleed air condition, in other words, that the actual output PWr is greater than the bleed air output PWbl, the bleed air controller instructs the bleed air valve 32 to close.

[0036] The switching controller 104 instructs the switch 56 to be in the ON state or the OFF state depending on whether the discharge conditions are satisfied. The discharge conditions include the actual output PWr detected by the power meter 53 being greater than the above-mentioned extraction steam output PWbl. Further, the discharge conditions include, for example, the externally required output PWc being greater than the rated output PWrad of the gas turbine 1, or the amount of change per unit time of the required output PWc being greater than a predetermined value. If the switching controller 104 determines that the discharge conditions are satisfied, it instructs the switch 56 to be in the ON state. On the other hand, if the switching controller 104 determines that the discharge conditions are not satisfied, it instructs the switch 56 to be in the OFF state.

[0037] Next, the operation of the gas turbine power plant according to this embodiment will be described with reference to the flowchart shown in FIG.

[0038] First, the case where the actual output PWr is equal to or greater than the intermediate output PWmid will be described.

[0039] The fuel controller 101 receives the externally required output PWc and the actual output PWr detected by the power meter 53, determines the opening of the fuel valve 5 according to the deviation between the required output PWc and the actual output PWr, and instructs the fuel valve 5 to this opening (fuel control process S1). Therefore, the flow rate of fuel supplied to the combustor 15 becomes a value that has a positive correlation with the required output PWc, as described above. The IGV controller 102 receives the actual output PWr detected by the power meter 53, determines the IGV opening θ according to this actual output PWr, and instructs the intake air regulator 13 to this IGV opening θ (IGV control process S2). In this case, the IGV opening θ becomes a value that has a positive correlation with the actual output PWr, as described above.

[0040] The bleed controller 103 determines whether or not the bleed condition is satisfied (bleed condition determination step S3). As described above, the bleed condition is that the actual output PWr is equal to or less than the bleed output PWbl, which is equal to or less than the intermediate output PWmid. Therefore, the bleed controller 103 determines that the bleed condition is not currently satisfied, and instructs the bleed valve 32 to close. Therefore, if the bleed valve 32 is in a closed state, the bleed valve 32 is maintained in the closed state, and if the bleed valve 32 is in an open state, the bleed valve 32 is closed, and part of the compressed air is not bled from the gas turbine 1 (bleed stop step S6).

[0041] The switching controller 104 determines whether the discharge conditions are satisfied (discharge condition determination step S7). It is assumed here that the switching controller 104 determines that the discharge conditions are not satisfied. In this case, the switching controller 104 instructs the switch 56 to be turned off. Therefore, if the switch 56 is in the off state, the switch 56 remains in the off state, and if the switch 56 is in the on state, the switch 56 is turned off, and the electricity stored in the storage battery 42 is not supplied to the external power grid 59 via the switch 56 (discharge stop step S9).

[0042] Next, a case where the actual output PWr is equal to or less than the extracted air output PWbl will be described.

[0043] As in the case where the actual output PWr is equal to or greater than the intermediate output PWmid, the fuel controller 101 receives the externally required output PWc and the actual output PWr detected by the power meter 53, determines the opening of the fuel valve 5 in accordance with the deviation between the required output PWc and the actual output PWr, and instructs the fuel valve 5 to this opening (fuel control process S1). Therefore, the flow rate of fuel supplied to the combustor 15 becomes a value that has a positive correlation with the required output PWc, as in the case where the actual output PWr is equal to or greater than the intermediate output PWmid. Furthermore, the IGV controller 102 receives the actual output PWr detected by the power meter 53, determines the IGV opening θ in accordance with this actual output PWr, and instructs the intake air regulator 13 to this IGV opening θ (IGV control process S2). In this case, because the actual output PWr is equal to or less than the extraction output PWbl, which is equal to or less than the intermediate output PWmid, the IGV opening θ is maintained at the minimum opening θmin, which is the same as the IGV opening θ when the actual output PWr is the intermediate output PWmid, unlike when the actual output PWr is equal to or greater than the intermediate output PWmid. In other words, in this case, the flow rate of air sucked into the compressor 10 is maintained at the flow rate when the actual output PWr is the intermediate output PWmid.

[0044] The bleed air controller 103 determines whether the bleed air conditions are satisfied (bleed air condition determination step S3). In this case, since the actual output PWr is equal to or less than the bleed air output PWbl, the bleed air controller 103 determines that the bleed air conditions are currently satisfied and instructs the bleed air valve 32 to open. As a result, the bleed air valve 32 opens, and part of the compressed air is bled from the gas turbine 1 as bleed air (bleed air step S4). This bleed air flows into the auxiliary turbine casing 35, causing the auxiliary turbine rotor 34 to rotate. As a result, the auxiliary generator 41 generates electricity. The AC power generated by the auxiliary generator 41 is converted to DC power by the AC / DC converter 44, and the electrical energy of this AC power is stored in the storage battery 42 (charging step S5).

[0045] The switching controller 104 determines whether the discharge conditions are met (discharge condition determination step S7). In this case, the switching controller 104 determines that the discharge conditions are not met. Therefore, the electricity stored in the storage battery 42 is not supplied to the external power grid 59 via the switch 56 (discharge stop step S9).

[0046] Assume that the extraction process S4 is not executed when the actual output PWr is equal to or less than the extraction output PWbl. In this case, the flow rate of fuel supplied to the combustor 15 has a value positively correlated with the required output PWc, while the flow rate of air drawn into the compressor 10 is maintained at the flow rate when the actual output PWr is the intermediate output PWmid. Therefore, the air flow rate supplied to the combustor 15 is maintained at the flow rate when the actual output PWr is the intermediate output PWmid. Therefore, the fuel-air ratio, which is the ratio of the fuel flow rate to the air flow rate in the combustor 15, is smaller than when the actual output PWr is the intermediate output PWmid. When the fuel-air ratio decreases, the temperature of the combustion gas flowing from the combustor 15 into the turbine 16 decreases, and the temperature of the steam generated in the heat recovery boiler 21 decreases. As a result, the output efficiency of the exhaust heat utilization equipment 20 decreases. Furthermore, when the fuel-air ratio decreases, the combustibility of the fuel deteriorates, and in the worst case, a misfire may occur.

[0047] As described above, in the present embodiment, when the actual output PWr is equal to or less than the extraction output PWbl, the extraction step S4 is executed, and part of the compressed air is extracted from the gas turbine 1. Therefore, in the present embodiment, even when the actual output PWr is equal to or less than the extraction output PWbl, the fuel-air ratio is maintained at approximately the same value as when the actual output PWr is the intermediate output PWmid, and it is possible to suppress a decrease in the output efficiency of the exhaust heat utilization facility 20 and to suppress a deterioration in the combustibility of the fuel.

[0048] Next, a case where the discharge condition is satisfied will be described. As described above, the discharge condition in this embodiment includes the actual output PWr detected by the power meter 53 being larger than the extracted steam output PWbl, the required output PWc being larger than the rated output PWrad of the gas turbine 1, or the amount of change in the required output PWc per unit time being larger than a predetermined value.

[0049] In this case, the fuel controller 101 receives the externally required output PWc and the actual output PWr detected by the power meter 53, as in the case where the actual output PWr is the intermediate output PWmid, determines the opening of the fuel valve 5 in accordance with the deviation between the required output PWc and the actual output PWr, and instructs the fuel valve 5 of this opening (fuel control process S1). Furthermore, in this case, the IGV controller 102 receives the actual output PWr detected by the power meter 53, as in the case where the actual output PWr is the intermediate output PWmid, determines the IGV opening θ in accordance with this actual output PWr, and instructs the intake air regulator 13 of this IGV opening θ (IGV control process S2).

[0050] The bleed controller 103 determines whether or not the bleed conditions are satisfied (bleed condition determination step S3). In this case, since the actual output PWr is greater than the bleed pressure, the bleed controller 103 determines that the bleed conditions are not satisfied and instructs the bleed valve 32 to close. Therefore, if the bleed valve 32 is in a closed state, the bleed valve 32 is maintained in the closed state, and if the bleed valve 32 is in an open state, the bleed valve 32 is closed, and a portion of the compressed air is not bled from the gas turbine 1 (bleed stop step S6). Therefore, in this case, the bleed step S4 and the charging step S5 are not executed.

[0051] The switching controller 104 determines whether or not the discharge conditions are satisfied (discharge condition determination step S7). In this case, the switching controller 104 determines that the discharge conditions are satisfied and instructs the switch 56 to turn on. As a result, the switch 56 turns on, and the electricity stored in the storage battery 42 is supplied to the external power system 59 via the switch 56 (discharge step S8).

[0052] As described above, in this embodiment, when the required output PWc is larger than the rated output PWrad of the gas turbine 1, or when the actual output PWr is larger than the extraction steam output PWbl and the rate of change of the required output PWc per unit time is larger than a predetermined value, the external power system 59 is supplied with power from the storage battery 42 in addition to power from the gas turbine generator 6. Therefore, this embodiment can handle cases where the required output PWc is larger than the rated output PWrad of the gas turbine 1, or when the rate of change of the required output PWc per unit time is larger than a predetermined value and cannot be handled by the gas turbine generator 6 alone. Moreover, as described above, this embodiment can handle cases where the required output PWc is equal to or smaller than the extraction steam output PWbl and the actual output PWr is set to be equal to or smaller than the extraction steam output PWbl, while suppressing a decrease in the output efficiency and deterioration of combustibility of the exhaust heat utilization facility 20.

[0053] Therefore, in this embodiment, it is possible to flexibly respond to fluctuations in the externally required output PWc.

[0054] Second Embodiment of Gas Turbine Power Plant Hereinafter, a second embodiment of a gas turbine power plant according to the present disclosure will be described with reference to FIGS. 4 and 5. FIG.

[0055] As shown in FIG. 4, the gas turbine power plant of this embodiment is a plant in which a carbon dioxide capture unit 60 is added to the gas turbine power plant of the first embodiment.

[0056] The carbon dioxide recovery device 60 includes an adsorbent 61 capable of adsorbing carbon dioxide in the atmosphere, a duct 62 in which the adsorbent 61 is arranged, a blower fan 63 capable of sending air into the duct 62 and directing the air to the adsorbent 61, a suction blower 64 capable of sucking in the carbon dioxide adsorbed in the adsorbent 61, and a carbon dioxide tank 65 capable of storing the carbon dioxide from the suction blower 64.

[0057] The blower fan 63 is electrically connected to a fan power line 67. This fan power line 67 is electrically connected to a portion of the auxiliary generator power line 43 between the storage battery 42 and the AC / DC converter 44. A heating medium line 68 is connected to the adsorbent 61. The heating medium line 68 can guide the exhaust gas in the duct 21d of the heat recovery boiler 21, the air heated by the heat of the exhaust gas, or the steam generated by the heat of the exhaust gas to the adsorbent 61.

[0058] Next, the operation of the gas turbine power plant according to this embodiment will be described with reference to the flowchart shown in FIG.

[0059] In the gas turbine power plant of this embodiment, similarly to the gas turbine power plant of the first embodiment, the fuel control step S1, the IGV control step S2, the extraction condition determination step S3, the extraction step S4, the charging step S5, the extraction stop step S6, the discharge condition determination step S7, the discharging step S8, and the discharge stop step S9 are executed. The gas turbine power plant of this embodiment also executes a carbon dioxide capture step S10. As described in the first embodiment, the auxiliary generator 41 starts power generation, and the AC power generated by the auxiliary generator 41 is converted to DC power by the AC / DC converter 44. A portion of the electrical energy of this DC power is then stored in the storage battery 42 (charging step S5). In this embodiment, the remainder of the DC power is supplied to the blower fan 63. As a result, the blower fan 63 is driven to guide the air to the adsorbent 61, and the carbon dioxide in the air is adsorbed by the adsorbent 61 (carbon dioxide capture step S10).

[0060] When it is assumed that the adsorbent 61 is saturated with respect to the adsorption of carbon dioxide, a heating medium is sent from a heating medium line 68 to the adsorbent 61, and the adsorbent 61 is heated by this heating medium. When the adsorbent 61 is heated, the carbon dioxide adsorbed in the adsorbent 61 is desorbed from the adsorbent 61. The desorbed carbon dioxide is sucked by a suction blower 64 and sent to a carbon dioxide tank 65.

[0061] As described above, in this embodiment, carbon dioxide in the atmosphere can be recovered using part of the surplus power generated by the auxiliary generator 41 .

[0062] In this embodiment, the fan power line 67 is electrically connected to a portion of the auxiliary generator power line 43 between the storage battery 42 and the AC / DC converter 44, and the blower fan 63 is driven by part of the power generated by the auxiliary generator 41. However, the fan power line 67 may also be electrically connected to a portion of the storage battery power line 54 between the storage battery 42 and the DC / AC converter 45. In this case, the blower fan 63 is driven by the power stored in the storage battery 42. Therefore, in this case, as long as a certain amount of power or more is stored in the storage battery 42, the carbon dioxide capture step S10 can be executed whether the auxiliary generator 41 is generating power or not.

[0063] Modifications The gas turbine power plant in the above embodiment includes the exhaust heat utilization facility 20. However, the gas turbine power plant does not necessarily need to include the exhaust heat utilization facility 20.

[0064] Furthermore, the present disclosure is not limited to the embodiments and modifications described above, and various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention as derived from the content defined in the claims and their equivalents.

[0065] [Additional Notes] The gas turbine power plants in the above-described embodiments and modifications can be understood, for example, as follows.

[0066] (1) A gas turbine power plant in a first aspect includes a gas turbine 1 having a compressor 10 capable of compressing air, a combustor 15 capable of burning fuel in the compressed air compressed by the compressor 10 to generate combustion gas, and a turbine 16 capable of driving the combustion gas, a gas turbine generator 6 connected to the gas turbine 1 and capable of generating electricity by driving the turbine 16, an extraction line 31 capable of extracting part of the compressed air generated by the compressor 10 as extraction air from the gas turbine 1, and a turbine connected to the extraction line 31. an auxiliary turbine 33 that can be driven by the bleed air flowing through the bleed line 31; an air bleed valve 32 that is provided in the bleed line 31; an auxiliary generator 41 that is connected to the auxiliary turbine 33 and that can generate electricity by driving the auxiliary turbine 33; a storage battery 42 that can store the electricity generated by the auxiliary generator 41; a gas turbine power line 51 that electrically connects the gas turbine generator 6 to an external power system 59; and a storage battery power line 54 that electrically connects the storage battery 42 to the external power system 59.

[0067] In this aspect, when the actual output PWr of the gas turbine 1 becomes equal to or less than a predetermined extraction output PWbl that is smaller than the rated output PWrad, the extraction valve 32 is opened, and part of the compressed air generated by the compressor 10 is extracted as extraction air to the outside of the gas turbine 1. Therefore, in this aspect, when the actual output PWr of the gas turbine 1 becomes equal to or less than the extraction output PWbl from the rated output PWrad and the flow rate of fuel supplied to the combustor 15 decreases accordingly, the flow rate of compressed air supplied to the combustor 15 also decreases, making it possible to suppress deterioration in fuel combustibility. Therefore, in this aspect, it is possible to cope with a case where the required output PWc is equal to or less than the extraction output PWbl and the actual output PWr is set to be equal to or less than the extraction output PWbl, while suppressing deterioration in fuel combustibility.

[0068] In this embodiment, the auxiliary turbine 33 is driven by the extracted air, and this drive generates electricity from the auxiliary generator 41. The electricity generated by the auxiliary generator 41 is stored in the storage battery 42.

[0069] In this embodiment, the external power system 59 can be supplied with power from the storage battery 42 in addition to power from the gas turbine generator 6. Therefore, this embodiment can handle cases where the gas turbine generator 6 alone cannot handle the demand, such as when the externally required output PWc is greater than the rated output PWrad.

[0070] Therefore, in this embodiment, it is possible to flexibly respond to fluctuations in the externally required output PWc.

[0071] (2) A gas turbine power plant according to a second aspect is the gas turbine power plant according to the first aspect, further comprising a control device 100. The control device 100 has a bleed controller 103 that instructs the bleed valve 32 to open when an actual output PWr that is an actual output of the gas turbine 1 becomes equal to or less than a predetermined bleed output PWbl that is smaller than a rated output PWrad of the gas turbine 1, and that instructs the bleed valve 32 to close when the actual output PWr becomes larger than the bleed output PWbl.

[0072] In this aspect, the bleed valve 32 can be opened when the actual output PWr of the gas turbine 1 becomes equal to or less than a predetermined bleed output PWbl that is smaller than the rated output PWrad of the gas turbine 1. Therefore, when the actual output PWr of the gas turbine 1 becomes equal to or less than the bleed output PWbl, part of the compressed air generated by the compressor 10 is bled to the outside of the gas turbine 1 as bleed air, so that the ratio of air to fuel in the combustor 15 does not increase, and as described above, deterioration of fuel combustibility can be suppressed. Furthermore, in this aspect, the auxiliary turbine 33 is driven by the bleed air, and this drive causes the auxiliary generator 41 to generate electricity, and the electricity generated by the auxiliary generator 41 is stored in the storage battery 42.

[0073] Furthermore, in this aspect, when the actual output PWr of the gas turbine 1 becomes larger than the extraction output PWbl, the bleed valve 32 can be closed. Therefore, when the actual output PWr of the gas turbine 1 becomes larger than the extraction output PWbl, part of the compressed air generated by the compressor 10 is not bled out of the gas turbine 1 as bleed air, the ratio of air to fuel in the combustor 15 does not decrease, and deterioration of fuel combustibility can be suppressed.

[0074] (3) A gas turbine power plant according to a third aspect is the gas turbine power plant according to the second aspect, further including a fuel valve 5 capable of adjusting a flow rate of fuel supplied to the combustor 15. The control device 100 has a fuel controller 101 that determines an opening degree of the fuel valve 5 in accordance with an external required output PWc for the gas turbine 1 and instructs the fuel valve 5 to change the opening degree.

[0075] In this embodiment, fuel can be supplied to the combustor 15 at a flow rate according to the required output PWc.

[0076] (4) A gas turbine power plant according to a fourth aspect is the gas turbine power plant according to the second or third aspect, further comprising a switch 56 that is provided in the storage battery power line 54 and that is capable of realizing an ON state in which the storage battery 42 is electrically connected to the external electric power system 59 and an OFF state in which the storage battery 42 is not electrically connected to the external electric power system 59. The control device 100 has a switching controller 104 that instructs the switch 56 to switch to the ON state when a discharge condition, part of which is that the actual output PWr is greater than the extracted steam output PWbl, is satisfied, and that instructs the switch 56 to switch to the OFF state when the discharge condition is not satisfied.

[0077] In this embodiment, when the discharge condition is satisfied, the switch 56 is turned on, and power from the storage battery 42 can be supplied to the external power system 59 .

[0078] (5) A gas turbine power plant according to a fifth aspect is the gas turbine power plant according to the fourth aspect, wherein the discharge conditions include a condition that an externally required output PWc of the gas turbine 1 is greater than a rated output PWrad of the gas turbine 1.

[0079] In this aspect, when the required output PWc is greater than the rated output PWrad of the gas turbine 1, the switch 56 is turned on, and power from the storage battery 42 can be supplied to the external power system 59. Therefore, in this aspect, even when the gas turbine generator 6 alone cannot cope with the situation, it is possible to cope with the situation.

[0080] (6) A gas turbine power plant in a sixth aspect is the gas turbine power plant in the fourth aspect, wherein the discharge conditions include a change per unit time in a required output PWc of the gas turbine 1 from the outside being greater than a predetermined value.

[0081] In this mode, when the amount of change per unit time of the required output PWc is greater than a predetermined value, the switch 56 is turned on, and power from the storage battery 42 can be supplied to the external power grid 59. Therefore, in this mode, even when the gas turbine generator 6 alone cannot cope with the situation, it is possible to cope with the situation.

[0082] (7) A seventh aspect of the gas turbine power plant is the gas turbine power plant of any one of the first to sixth aspects, further comprising a carbon dioxide capture device 60 capable of capturing carbon dioxide from the atmosphere using the electric power generated by the auxiliary generator 41 or the electric power stored in the storage battery 42.

[0083] In this embodiment, carbon dioxide in the atmosphere can be recovered using part of the surplus power generated by the auxiliary generator 41.

[0084] (8) A gas turbine power plant according to an eighth aspect is the gas turbine power plant according to the seventh aspect, wherein the carbon dioxide capture device 60 has an adsorbent 61 capable of adsorbing carbon dioxide, and a blower fan 63 capable of directing air to the adsorbent 61 using electric power generated by the auxiliary generator 41 or electric power stored in the storage battery 42.

[0085] (9) A ninth aspect of the gas turbine power plant is the gas turbine power plant of the seventh or eighth aspect, wherein the carbon dioxide capture device 60 is capable of capturing carbon dioxide from the atmosphere using the electric power stored in the storage battery 42.

[0086] In this embodiment, as long as a certain amount of electricity is stored in the storage battery 42, carbon dioxide can be recovered from the atmosphere whether the auxiliary generator 41 is generating electricity or not.

[0087] The operation methods of the gas turbine power plant in the above embodiments and modified examples can be understood, for example, as follows: (10) A method of operating a gas turbine power plant in a tenth aspect is applied to the following gas turbine power plant: This gas turbine power plant includes a gas turbine 1 having a compressor 10 capable of compressing air, a combustor 15 capable of generating combustion gas by burning fuel in the compressed air compressed by the compressor 10, and a turbine 16 capable of driving the combustion gas, and a gas turbine generator 6 connected to the gas turbine 1, capable of generating electricity by driving the turbine 16, and transmitting the electricity to an external power grid 59. In the operation method of the gas turbine power plant according to this aspect, when an actual output PWr that is the actual output of the gas turbine 1 becomes equal to or less than a predetermined extraction output PWbl that is smaller than a rated output PWrad of the gas turbine 1, the method executes an extraction step S4 of extracting part of the compressed air generated by the compressor 10 as extraction air to the outside of the gas turbine 1 and reducing the flow rate of the compressed air flowing into the combustor 15, and a charging step S5 of storing electricity in a storage battery 42 that can discharge to the external power system 59. In the charging step S5, an auxiliary turbine 33 is driven by the extraction air, an auxiliary generator 41 is driven to generate electricity by driving the auxiliary turbine 33, and the electricity generated by the auxiliary generator 41 is stored in the storage battery 42.

[0088] In this aspect, similar to the gas turbine power plant of the first aspect, it is possible to flexibly respond to fluctuations in the external required output PWc.

[0089] (11) In an eleventh aspect, in the gas turbine power plant operation method according to the tenth aspect, when the actual power output PWr is greater than the extracted power output PWbl, the extracting step S4 is not executed.

[0090] In this aspect, similarly to the gas turbine power plant in the second aspect, when the actual output PWr is larger than the extraction output PWbl, a portion of the compressed air generated by the compressor 10 is not extracted as extraction air to the outside of the gas turbine 1. Therefore, in this case, in this aspect, the ratio of air to fuel in the combustor 15 does not decrease, and deterioration of the combustibility of the fuel can be suppressed.

[0091] (12) A twelfth aspect of the gas turbine power plant operation method is the method for operating a gas turbine power plant according to the tenth aspect, wherein the gas turbine power plant includes a fuel valve 5 that can adjust a flow rate of fuel supplied to the combustor 15. The operation method of this aspect further executes a fuel control step S1 that determines a valve aperture of the fuel valve 5 in accordance with an external required output PWc of the gas turbine 1, and instructs the fuel valve 5 to change the valve aperture.

[0092] In this embodiment, similarly to the gas turbine power plant of the third embodiment, fuel can be supplied to the combustor 15 at a flow rate according to the required output PWc.

[0093] (13) In a thirteenth aspect, the gas turbine power plant operation method according to any one of the tenth to twelfth aspects further executes a discharging step S8 in which, when a discharge condition is satisfied, the electricity stored in the storage battery 42 is discharged from the storage battery 42 to the external power grid 59. When the discharge condition is not satisfied, the discharging step S8 is not executed.

[0094] In this embodiment, similarly to the gas turbine power plant in the fourth embodiment, when the discharge condition is satisfied, the power from the storage battery 42 can be supplied to the external power grid 59 .

[0095] (14) A fourteenth aspect of the gas turbine power plant operation method is the thirteenth aspect of the gas turbine power plant operation method, wherein the discharge conditions include a condition that an externally required output PWc of the gas turbine 1 is greater than a rated output PWrad of the gas turbine 1.

[0096] In this aspect, similarly to the gas turbine power plant in the fifth aspect, when the required output PWc is greater than the rated output PWrad of the gas turbine 1, electric power from the storage battery 42 can be supplied to the external electric power system 59. Therefore, in this aspect, even when the gas turbine generator 6 alone cannot cope with the situation, it is possible to cope with the situation.

[0097] (15) In a fifteenth aspect, the method for operating a gas turbine power plant is the method for operating a gas turbine power plant in the thirteenth aspect, wherein the discharge condition includes a condition that a change per unit time in an output PWc required from the outside to the gas turbine 1 is greater than a predetermined value.

[0098] In this aspect, similarly to the gas turbine power plant in the sixth aspect, when the amount of change per unit time of the required output PWc is greater than a predetermined value, electric power from the storage battery 42 can be supplied to the external electric power system 59. Therefore, in this aspect, even when the gas turbine generator 6 alone cannot cope with the situation, it is possible to cope with the situation.

[0099] (16) A sixteenth aspect of the gas turbine power plant operation method is the method for operating a gas turbine power plant according to any one of the tenth to fifteenth aspects, further comprising a carbon dioxide recovery step S10 of recovering carbon dioxide from the atmosphere using electric power generated by the auxiliary generator or electric power stored in the storage battery 42.

[0100] In this embodiment, like the gas turbine power plant of the seventh embodiment, carbon dioxide in the atmosphere can be recovered using part of the surplus electricity generated by the auxiliary generator 41.

[0101] (17) A seventeenth aspect of the gas turbine power plant operating method is the sixteenth aspect of the gas turbine power plant operating method, wherein the carbon dioxide recovery step S10 is performed using electric power stored in the storage battery 42.

[0102] In this aspect, as with the gas turbine power plant in the ninth aspect, as long as a certain amount of electricity is stored in the storage battery 42, carbon dioxide can be recovered from the atmosphere whether the auxiliary generator 41 is generating electricity or not.

[0103] According to one aspect of the present disclosure, it is possible to flexibly respond to fluctuations in externally required output.

[0104] 1: Gas turbine 2: Gas turbine rotor 3: Intermediate casing 4: Fuel line 5: Fuel valve 6: Gas turbine generator 10: Compressor 11: Compressor rotor 11s: Compressor rotor shaft 11b: Row of moving blades 12: Compressor casing 13: Inlet air volume regulator 13v: Inlet guide vane (IGV) 13d: Driver 15: Combustor 16: Turbine 17: Turbine rotor 17s: Turbine rotor shaft 17b: Row of moving blades 18: Turbine casing 20: Waste heat utilization equipment 21: Waste heat recovery boiler 21d: Duct 21t: Heat transfer tube 22: Chimney 23: Steam turbine 24: Main steam line 25: Condenser 26: Feedwater line 27: Feedwater pump 30: Extraction equipment 31: Extraction line 32: Extraction valve 33: Auxiliary turbine 34: Auxiliary turbine rotor 35: Auxiliary turbine casing 40: Auxiliary power generating equipment 41: Auxiliary generator 42: Storage battery 43: Auxiliary generator power line 44: AC / DC converter 45: DC / AC converter 50: Power system equipment 51: Gas turbine power line 52: Transformer 53: Output meter 54: Storage battery power line 55: Transformer 56: Switch 59: External power system 60: Carbon dioxide capture device 61: Absorbent 62: Duct 63: Blower fan 64: Suction blower 65: Carbon dioxide tank 67: Fan power line 68: Heating medium line 100: Control device 101: Fuel controller 102: IGV controller 103: Bleed controller 104: Switching controller A: Air F: Fuel Ar: Rotor axis Da: Axial direction Dau: Axial upstream side Dad: Axial downstream side

Claims

1. A gas turbine power plant comprising: a gas turbine having a compressor capable of compressing air, a combustor capable of generating combustion gas by burning fuel in the compressed air compressed by the compressor, and a turbine capable of driving the combustion gas; a gas turbine generator connected to the gas turbine and capable of generating electricity by driving the turbine; an extraction line capable of extracting from the gas turbine a part of the compressed air generated by the compressor as extraction air, an auxiliary turbine connected to the extraction line and capable of being driven by the extraction air flowing through the extraction line; an extraction valve provided in the extraction line; an auxiliary generator connected to the auxiliary turbine and capable of generating electricity by driving the auxiliary turbine; a storage battery capable of storing electricity generated by the auxiliary generator; a gas turbine power line electrically connecting the gas turbine generator to an external power system; and a storage battery power line electrically connecting the storage battery to the external power system.

2. A gas turbine power plant according to claim 1, further comprising a control device, the control device having an bleed controller which instructs the bleed valve to open when an actual output, which is the actual output of the gas turbine, falls below a predetermined bleed output which is smaller than the rated output of the gas turbine, and which instructs the bleed valve to close when the actual output becomes larger than the bleed output.

3. A gas turbine power plant as claimed in claim 2, further comprising a fuel valve capable of adjusting the flow rate of fuel supplied to the combustor, and the control device has a fuel controller which determines the opening degree of the fuel valve in accordance with an external required output for the gas turbine, and instructs the fuel valve to said opening degree.

4. A gas turbine power plant as claimed in claim 2 or 3, further comprising a switch provided in the battery power line and capable of realising an on state in which the storage battery is electrically connected to the external power system and an off state in which the storage battery is not electrically connected to the external power system, and the control device has a switching controller which instructs the switch to be in the on state when a discharge condition is satisfied, the condition being partly that the actual output is greater than the extraction output, and which instructs the switch to be in the off state when the discharge condition is not satisfied.

5. A gas turbine power plant according to claim 4, wherein the discharge conditions include a condition that an externally required output for the gas turbine is greater than a rated output of the gas turbine.

6. A gas turbine power plant according to claim 4, wherein the discharge condition includes a condition that a change in a required output from an external source to the gas turbine per unit time is greater than a predetermined value.

7. The gas turbine power plant according to any one of claims 1 to 3, further comprising a carbon dioxide recovery device capable of recovering carbon dioxide from the atmosphere using the electric power generated by the auxiliary generator or the electric power stored in the storage battery.

8. A gas turbine power plant according to claim 7, wherein the carbon dioxide capture device comprises: an adsorbent capable of adsorbing carbon dioxide; and a blower fan capable of directing air to the adsorbent using electric power generated by the auxiliary generator or electric power stored in the storage battery.

9. A gas turbine power plant according to claim 7, wherein the carbon dioxide capture device is capable of capturing carbon dioxide from the atmosphere using the electric power stored in the storage battery.

10. A method for operating a gas turbine power plant including a gas turbine having a compressor capable of compressing air, a combustor capable of generating combustion gas by burning fuel in the compressed air compressed by the compressor, and a turbine capable of driving the combustion gas, and a gas turbine generator connected to the gas turbine and capable of generating electricity by driving the turbine and transmitting the electricity to an external power system, the method comprising the steps of: when an actual output that is the actual output of the gas turbine falls to or below a predetermined extraction output that is smaller than the rated output of the gas turbine, extracting a part of the compressed air generated by the compressor as extraction air to the outside of the gas turbine to reduce the flow rate of the compressed air flowing into the combustor; and a charging step of storing electricity in a storage battery that can be discharged to the external power system, wherein in the charging step, an auxiliary turbine is driven by the extraction air, an auxiliary generator is driven by the auxiliary turbine to generate electricity, and the electricity generated by the auxiliary generator is stored in the storage battery.

11. A method for operating a gas turbine power plant according to claim 10, wherein the extraction process is not performed when the actual output is greater than the extraction output.

12. A method for operating a gas turbine power plant as claimed in claim 10, wherein the gas turbine power plant is provided with a fuel valve capable of adjusting the flow rate of fuel supplied to the combustor, and further comprises a fuel control step of determining a valve opening degree of the fuel valve in response to an external required output for the gas turbine, and instructing the fuel valve to set the valve opening degree.

13. A method for operating a gas turbine power plant according to any one of claims 10 to 12, further comprising the steps of: when a discharge condition is satisfied, the discharge condition being partly that the actual output is greater than the extraction output, discharging the electricity stored in the storage battery from the storage battery to the external power system; and when the discharge condition is not satisfied, not executing the discharge step.

14. A method for operating a gas turbine power plant according to claim 13, wherein the discharge condition includes a condition in which an externally requested output of the gas turbine is greater than a rated output of the gas turbine.

15. A method for operating a gas turbine power plant according to claim 13, wherein the discharge condition includes a change per unit time in an output required from outside for the gas turbine being greater than a predetermined value.

16. A method for operating a gas turbine power plant according to any one of claims 10 to 12, further comprising carrying out a carbon dioxide capture process for capturing carbon dioxide from the atmosphere using the electric power generated by the auxiliary generator or the electric power stored in the storage battery.

17. A method for operating a gas turbine power plant according to claim 16, wherein the carbon dioxide capture process is carried out using the electric power stored in the storage battery.

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