GAS TURBINE CONTROL DEVICE, GAS TURBINE PLANT AND GAS TURBINE CONTROL METHOD

Abstract

A gas turbine control device (300) comprising: a first estimation unit (291) configured to estimate a first temperature (T1T f ) which is a first turbine inlet temperature estimate based on a first model which is a physical model using a fuel flow rate to a gas turbine (110), a second estimation unit (292) configured to determine a second temperature (T1T t ) which is a second turbine inlet temperature estimate based on a second model which is a physical model using an exhaust gas temperature of the gas turbine (110), an input value correction unit (394) configured to correct an estimated value to be input into the first model using an estimated value obtained by the calculation using the second model, and a correction unit (293) configured to correct the first temperature (T1T f ) based on the second temperature (T1T t ) by using a delay element to calculate a corrected turbine inlet temperature estimate such that the corrected turbine inlet temperature estimate during a steady-state phase of the gas turbine (110) is equal to the second temperature (T1T t ) becomes.

Description

[0001] The present invention relates to a gas turbine control device, a gas turbine plant and a gas turbine control method.

[0002] In some cases, a turbine inlet temperature can be used to control a gas turbine. Conversely, in some cases, a gas turbine inlet can reach a high temperature, and it is difficult to measure the turbine inlet temperature with high accuracy. Therefore, techniques for estimating a turbine inlet temperature are proposed. For example, JP 2005-240608 A describes a technique for estimating a turbine inlet temperature based on a heat balance in a combustor of a gas turbine.

[0003] JP 2016-23604 A discloses a gas turbine control device comprising first and second temperature estimation units, each estimating a turbine inlet temperature based on a physical model, an input value correction unit, and a correction unit. The input value correction unit can correct an estimated value to be input to the first model using an estimated value obtained by calculation using the second model. The correction unit can correct the first estimated turbine inlet temperature based on the second estimated turbine inlet temperature by using a predetermined coefficient.

[0004] By estimating a turbine inlet temperature based on the heat balance in a combustor, responsiveness during a transient phase can be ensured. Furthermore, if the estimation accuracy of the turbine inlet temperature can be improved, the control accuracy of the gas turbine can be improved.

[0005] The present invention solves the technical problem by a gas turbine control device having the features of patent claim 1, a gas turbine plant having the features of patent claim 5 and a gas turbine control method having the features of patent claim 6, which can ensure the responsiveness in estimating a turbine inlet temperature and improve the estimation accuracy.

[0006] According to the present invention, a gas turbine control device includes a first estimation unit configured to estimate a first temperature, which is a turbine inlet temperature estimate, based on a first model, which is a physical model using a fuel flow rate to a gas turbine, a second estimation unit configured to estimate a second temperature, which is a turbine inlet temperature estimate, based on a second model, which is a physical model using an exhaust gas temperature of the gas turbine, and a correction unit configured to correct the first temperature based on the second temperature to calculate a turbine inlet temperature estimate.

[0007] The first estimation unit may estimate the first temperature based on the first model indicating a heat balance in a combustor, the second estimation unit may estimate the second temperature based on the second model indicating a heat balance using an exhaust gas temperature of the gas turbine, and the correction unit may correct the first temperature using a correction coefficient determined based on a relationship between the first temperature and the second temperature.

[0008] The gas turbine control device includes an input value correction unit configured to correct at least one of estimated values ​​to be input to the first model using an estimated value obtained by the calculation using the second model.

[0009] According to the present invention, a gas turbine plant comprises the gas turbine control device described above.

[0010] According to the present invention, a gas turbine control method includes estimating a first temperature, which is a turbine inlet temperature estimate, based on a first model, which is a physical model using a fuel flow rate to a gas turbine, estimating a second temperature, which is a turbine inlet temperature estimate, based on a second model, which is a physical model using an exhaust gas temperature of the gas turbine, and correcting the first temperature based on the second temperature to calculate a turbine inlet temperature estimate.

[0011] According to the gas turbine control apparatus, the gas turbine plant, and the gas turbine control method described above, responsiveness in estimating the gas turbine inlet temperature can be ensured, and the estimation accuracy can be improved. Short description of the drawings: Fig. 1 is a schematic block diagram illustrating a functional configuration of a gas turbine plant according to an example for better understanding of the present invention. Fig. 2 is a schematic configuration view showing a configuration of a plant main body according to the example for better understanding. Fig. 3 is a schematic block diagram illustrating a functional configuration of a gas turbine control apparatus according to the example for better understanding. Fig. 4 is a graph illustrating a first example of a first turbine inlet temperature estimate based on a heat balance model using a generator output in the example for better understanding. Fig. 5 is a graph illustrating a second example of a turbine inlet temperature estimation based on the heat balance model using a generator output in the example for better understanding. Fig. 6 is a graph showing an example of a value of a function LAG according to the example for better understanding. Fig. 7 is a diagram illustrating an example of a processing flow in which the gas turbine control apparatus according to the example acquires a turbine inlet temperature estimate for better understanding. Fig. 8 is a schematic block diagram illustrating a functional configuration of a gas turbine control apparatus according to an embodiment. Fig. 9 is a view illustrating an example of a processing flow in which the gas turbine control apparatus according to the embodiment calculates a turbine inlet temperature estimation value.

[0012] The following describes an example for better understanding and an embodiment of the present invention. Not all combinations of features described are essential for achieving the invention. Example for better understanding

[0013] Fig. 1 is a schematic block diagram illustrating a functional configuration of a gas turbine plant according to the example for better understanding. As shown in Fig. 1, the gas turbine plant 1 comprises a plant main body 100 and a gas turbine control device 200.

[0014] In the following, a case where the gas turbine plant 1 is a gas turbine power plant will be described as an example. However, the gas turbine plant 1 is not limited to the gas turbine power plant and can be any plant in which a gas turbine is provided.

[0015] The plant main body 100 operates in accordance with the control of the gas turbine control device 200 to generate rotational energy and generate electric power using the generated rotational energy.

[0016] Fig. 2 is a schematic configuration view showing a configuration example of the system main body 100. In the example of Fig. 2, the plant main body 100 includes a gas turbine 110 and a generator 120. The gas turbine 110 includes an inlet guide vane 111, a compressor 112, a casing 113, a combustion chamber 114, a turbine 115, and a rotating shaft 116.

[0017] The gas turbine 110 burns the fuel gas to generate rotational energy.

[0018] The compressor 112 draws in air (atmospheric air) and compresses it. The compressed air obtained by the compressor 112 flows into the combustion chamber 114 via the casing 113. The intake guide vane 111 is provided at an air inlet of the compressor 112. The intake guide vane 111 adjusts an amount of intake air for the compressor 112 by adjusting an opening degree of the intake guide vane 111 in accordance with the control of the gas turbine control device 200.

[0019] The combustion chamber 114 mixes the fuel gas supplied from a fuel supply line and the compressed air from the compressor 112 and combusts the mixture. The combustion gas generated by the combustion flows into the turbine 115 and impacts the blades of the turbine 115 to rotate the turbine 115.

[0020] The turbine 115, the compressor 112, and the generator 120 are connected by the rotating shaft 116. The rotating shaft 116 transmits the rotational energy from the turbine 115 to the compressor 112, and the compressor 112 compresses the air using the rotational energy from the turbine 115. Furthermore, the rotating shaft 116 transmits the rotational energy from the turbine 115 to the generator 120, and the generator 120 converts the electrical energy generated by the rotational energy from the turbine 115.

[0021] The gas turbine control device 200 controls the plant main body 100. More specifically, the gas turbine control device 200 obtains a turbine inlet temperature estimate in real time and controls the gas turbine 110 based on the obtained estimate. The turbine inlet temperature mentioned here is a temperature at the combustion gas inlet of the turbine 115.

[0022] The gas turbine control device 200 is formed, for example, using a computer such as an engineering work station (EWS) or a programmable logic controller (PLC).

[0023] Fig. 3 is a schematic block diagram illustrating a functional configuration of the gas turbine control device 200. As in Fig. As shown in Figure 3, the gas turbine control device 200 includes a communication unit 210, an operation input unit 220, a display unit 230, a storage unit 280, and a control unit 290. The control unit 290 includes a first estimation unit 291, a second estimation unit 292, and a correction unit 293.

[0024] The communication unit 210 performs communication with other devices. Specifically, the communication unit 210 receives sensor data from each sensor provided in the system main body 100. Furthermore, the communication unit 210 transmits a control signal to each unit of the system main body 100.

[0025] The operation input unit 220 includes an input device such as a control panel or a keyboard or a combination thereof and receives a user operation.

[0026] The display unit 230 includes a display device such as a screen for a monitor console or a liquid crystal panel or a combination thereof, and displays various types of information.

[0027] The storage unit 280 is formed using a storage device included in the gas turbine control device 200 and stores various types of information.

[0028] The control unit 290 controls each unit of the gas turbine control device 200 to perform various functions. The control unit 290 is formed, for example, by a central processing unit (CPU) included in the gas turbine control device 200, which reads and executes a program from the storage unit 280.

[0029] The first estimation unit 291 estimates a first temperature. The first temperature mentioned here is a turbine inlet temperature estimate based on a first model. The first model mentioned here is a physical model using a fuel flow rate to the gas turbine. The physical model using the fuel flow rate to the gas turbine mentioned here is a model that receives an input of the fuel flow rate to the gas turbine and calculates a physical value. A known model can be used as the first model.

[0030] The data format of the physical model in the gas turbine control device 200 is not limited to a specific format. For example, the physical model may be represented in the form of a mathematical formula such as a function or an equation, or may be represented in the form of a table representing a correspondence between the input and the output.

[0031] A relationship between a change in fuel flow rate and a change in turbine inlet temperature is a relationship in which the turbine inlet temperature changes in accordance with the change in fuel flow rate. Specifically, the flow rate or temperature of the combustion gas obtained by burning the fuel changes in accordance with the change in fuel flow rate, and the temperature of the turbine inlet heated by the combustion gas changes. Therefore, when the first estimation unit 291 estimates the turbine inlet temperature using the fuel flow rate to the gas turbine 110, the change in the turbine inlet temperature relative to the change in fuel flow rate can be estimated without delay.In this respect, the first temperature estimated by the first estimation unit 291 has a good response during a transient when the state of the gas turbine changes.

[0032] The first estimation unit 291 may use a physical model indicating the heat balance in the combustion chamber as the first model. For example, the first estimation unit 291 may use a cP4×Vcb×γ4×dT4dt=cPf×G′f×T′f+cP3×G′3×T′3+η×Hf×G′f−cP4×G′4×T4

[0033] Use the model described in Japanese Unexamined Patent Application, First Publication No. 2005-240608. Math 1 C P4 is a combustion gas specific heat [kcal / kg°C]. V cb is a volume [m 3 ] of a housing to a rear cylinder of the turbine. γ4 is a combustion gas specific density [kg / m 3 ]. T4 is a turbine inlet temperature [°C] to be estimated. t is a time [sec]. c Pf is a fuel-specific heat [kcal / kg°C]. G' f is a delay compensated fuel flow rate measurement [kg / s]. T' f is a delay-compensated fuel temperature measurement value [°C]. c P3 is a housing-specific heat [kcal / kg°C]. G'3 is a delay-compensated combustion chamber inlet air flow rate measurement [kg / s]. A calculated value can be used as G'3. T'3 is a delay-compensated case temperature measurement [°C]. η is the efficiency of the combustion chamber [kcal / kg]. H f is a calorific value [kcal / kg]. G'4 is a delay-compensated turbine inlet combustion gas flow rate [kg / s]. G'4 = G'3 + G' f . η and V cbare design values ​​that are calculated in the design phase.

[0034] The second estimation unit 292 estimates a second temperature. The second temperature mentioned here is a turbine inlet temperature estimate based on the second model. The second model mentioned here is a physical model using the exhaust gas temperature of the gas turbine. The physical model using the exhaust gas temperature of the gas turbine mentioned here is a model that receives an input of the exhaust gas temperature of the gas turbine and calculates a physical value. A known model can be used as the second model.

[0035] The exhaust gas temperature is a temperature when the combustion gas is discharged from the turbine as exhaust gas through the turbine. Therefore, the turbine inlet temperature and the exhaust gas temperature are respectively temperatures of the combustion gas at the inlet and outlet of the turbine and are highly correlated with each other. When the second estimation unit 292 estimates the turbine inlet temperature based on the exhaust gas temperature, the turbine inlet temperature (second temperature) can be estimated with high accuracy. Specifically, the second temperature is more accurate than the first temperature during steady-state periods when the state of the gas turbine is constant.

[0036] In contrast, while the turbine inlet temperature is the temperature of the combustion gas before it passes through the turbine, the exhaust gas temperature changes later than the change in the turbine inlet temperature because the exhaust gas temperature is the temperature of the combustion gas after it passes through the turbine. Furthermore, a delay generally occurs in the temperature measurement by the temperature sensor. More specifically, if accurate measurement of the exhaust gas temperature is desired, the large measurement delay must be taken into account. For this reason, the first temperature estimated by the first estimation unit 291 has a better response during a transient phase in which the state of the gas turbine changes than the second temperature estimated by the second estimation unit 292.

[0037] The second estimation unit 292 may use a model representing a heat balance using the exhaust gas temperature of the gas turbine as the second model. An example of the second model used by the second estimation unit 292 will be described below with reference to formulas (2) to (8).

[0038] Work Wt of the turbine is expressed by formula (2). Math 2 Wt=ΔH×Gt

[0039] ΔH is a heat drop (an enthalpy difference) of the gas turbine. G t is a turbine passage flow rate (a flow rate of a combustion gas passing through the turbine).

[0040] The heat drop ΔH in the turbine is expressed by the formula (3). [Math. 3] ΔH=H1T−H2T

[0041] H 1T is an enthalpy of the turbine inlet. H 2T is an enthalpy of the turbine outlet.

[0042] Formula (4) is obtained through formula (2) and formula (3). [Math. 4] wtGt=H1T−H2T

[0043] Formula (4) can be converted into formula (5) [Math. 5] H1T=H2T+wtGt

[0044] When a relational expression is used to convert enthalpy to temperature, the second temperature T1T t , which is a turbine inlet temperature estimate, is expressed by the formula (6). [Math. 6] T1Tt=f(H1T)

[0045] The function f here is a function determined by physical properties. For example, the storage unit 280 stores the function f in advance.

[0046] Formula (7) is obtained by formula (5) and formula (6). [Math. 7] T1Tt=f(H2T+wtGt)

[0047] The second estimation unit 292 may use the model represented by formula (7) as the second model. In this case, the second estimation unit 292 calculates the work W t of the turbine from the generator output or generator power Pe based on formula (8). [Math. 8] Pe=Wt+Wc+WLOSS

[0048] W c is the work of the compressor and W LOSS is a mechanical loss (mecha-loss). The second estimation unit 292 obtains the value of W c and the value of W LOSS by a calculation.

[0049] In addition, the second estimation unit 292 may use a measured value or a calculated value as the turbine passage flow rate Gt in formula (7). In addition, the second estimation unit 292 calculates the enthalpy H 2T of the turbine outlet based on a known enthalpy calculation method.

[0050] The correction unit 293 corrects the first temperature based on the second temperature and calculates the turbine inlet temperature estimate.

[0051] The correction unit 293 may correct the first temperature using a correction coefficient determined based on the ratio of the first temperature to the second temperature. For example, the correction unit 293 may calculate the correction coefficient X based on Formula (9). [Math. 9] X=α×T1TtT1Tf+(1−α)×X′ α is an adjustment coefficient represented by a constant of 0 < α ≤ 1. The value of the adjustment coefficient α is set or selected, for example, in accordance with an input operation performed by the user using the operation input unit 220.

[0052] T1T t is a second temperature. T1T f is a first temperature.

[0053] X' is a past value of the correction coefficient X. For example, the value of the correction coefficient X in a previous calculation cycle can be used as the value X'.

[0054] As indicated by “T1Tt / T1T f “ in formula (9), the correction coefficient X corresponds to an example of the correction coefficient determined based on the ratio of the first temperature to the second temperature.

[0055] The correction unit 293 corrects the first temperature using the correction coefficient X as shown in formula (10). [Math. 10] T1Te=X×T1Tf

[0056] T1T e is a turbine inlet temperature estimate.

[0057] When formula (9) is substituted into “X” of formula (10), formula (11) is obtained. [Math. 11] T1Te=α×T1Tt+(1−α)×X′×T1Tf

[0058] In formula (11), a weighting is calculated by multiplying each of the first temperature T1T f and the second temperature T1Tt with a coefficient and these values ​​are summed.

[0059] During a transition where the state of the gas turbine changes, the turbine inlet temperature estimate T1T e a better response than in the case where only the second temperature T1T t by the expression (“(1-α)×X'×T1T f “) of the first temperature T1T f is obtained.

[0060] In addition, during the stationary time or phase, in which the state of the gas turbine is constant, the turbine inlet temperature estimate T1T e a higher accuracy than that of the case where only the first temperature T1T f by the expression (“α×T1T t “) of the second temperature T1T t is obtained.

[0061] Since the second temperature T1T t in the turbine inlet temperature estimate T1T e by the correction unit 293, which determines the first temperature T1T f corrected, reflected, or reflected in the process, it is not necessary to switch the process between the stationary phase and the transient phase. This can avoid a sudden change in the estimated value when switching the process. Since it is not necessary to determine whether the process is stationary or transient, and it is not necessary to switch or change the process, the load on the control unit 290 can be reduced.

[0062] With reference to Fig. 4 and Fig. 5, the accuracy of the turbine inlet temperature estimate T1T e by the gas turbine control device 200 in comparison with the case of estimating based on the heat balance model using the generator output.

[0063] Fig. 4 is a graph illustrating a first example of the turbine inlet temperature estimation based on the heat balance model using the generator output. Fig. Figure 4 shows an example of the turbine inlet temperature estimation based on the heat balance model using the generator output during a time or phase when the turbine load increases.

[0064] The horizontal axis of Fig. 4 is time. The vertical axis is temperature.

[0065] Line L11 is an example of the actual turbine inlet temperature. Line L12 is an example of the turbine inlet temperature estimate based on the heat balance model using the generator output. As an estimation of the turbine inlet temperature based on the heat balance model using the generator output, for example, a GT output measurement, an ambient temperature measurement, and an IGV opening degree command value can be applied to the heat balance data to estimate the turbine inlet temperature estimate.

[0066] The combustion gas flowing into the turbine impacts the moving blades of the turbine to rotate the moving blades and the rotating shaft, and the generator generates electrical energy through the rotational energy transmitted to the generator through the rotating shaft. For this reason, a delay such as a delay due to the inertia of the rotating shaft or the like occurs from the change in the turbine inlet temperature to the change in the generator output. Therefore, as in the example of Fig. 4 when estimating the turbine inlet temperature based on the heat equilibrium model using the generator output, the change in the estimated value of the turbine inlet temperature is later than the change in the actual value.

[0067] In contrast, as described above, in the gas turbine control device 200, by reflecting the first temperature T1T fbased on the fuel flow rate in the turbine inlet temperature estimate T1T e A higher responsiveness can be achieved than in a case where the turbine inlet temperature is estimated based on the heat balance model using the generator output. In this regard, in the gas turbine control device 200, the turbine inlet temperature can be estimated with high accuracy even during the transition period compared to a case where the turbine inlet temperature is estimated based on the heat balance model using the generator output.

[0068] Fig. 5 is a graph illustrating a second example of turbine inlet temperature estimation based on the heat balance model using the generator output. Fig. Figure 5 illustrates an example of the turbine inlet temperature estimation based on the heat balance model using the generator output during the time or phase when the turbine load drops.

[0069] The horizontal axis of Fig. 5 is time. The vertical axis is temperature.

[0070] Line L21 is an example of the actual turbine inlet temperature. Line L22 is an example of a turbine inlet temperature estimate based on the heat balance model using the generator output.

[0071] When a generator output changes, in some cases the generator output may fluctuate due to a relationship with the electrical power system. Therefore, as in the example from Fig. 5, considers that the turbine inlet temperature estimate fluctuates on the heat equilibrium model using the generator output. On the other hand, this fluctuation is due to the relationship between the generator and the power system, and considers that the turbine inlet temperature changes as in the example from Fig. 5 changes without fluctuation.

[0072] If the gas turbine is controlled using the gas turbine inlet temperature estimate that deviates significantly from the actual turbine inlet temperature, stuttering due to misfire or damage to the combustor due to combustor oscillation may occur.

[0073] In contrast, as described above, in the gas turbine control device 200, the influence of fluctuations on the generator output can be avoided or reduced by controlling the first temperature T1T fbased on the fuel flow rate in the turbine inlet temperature estimate T1T e In this regard, in the gas turbine control device 200, the turbine inlet temperature can be estimated with higher accuracy even during the transition period, compared with the case where the turbine inlet temperature is estimated based on the heat balance model using the generator output.

[0074] Furthermore, the correction performed by the correction unit 293 is not limited to that shown in formulas (10) and (11). Various corrections that ensure responsiveness during the transient phase based on the first temperature and achieve accuracy during the steady-state phase based on the second temperature can be used as the correction performed by the correction unit 293.

[0075] For example, the correction unit 293 may adjust the turbine inlet temperature estimate T1T e based on formula (12). [Math. 12] T1Te=T1Tf+T1Tf−LAG(T1Tf)

[0076] Here LAG is a function that represents a first-order delay element.

[0077] Fig. Figure 6 is a graph showing an example of the value of the LAG function. Fig. 6 represents the value of the LAG function in the case where the input value to the LAG function is constant with respect to time.

[0078] As in the example from Fig. 6, the output value of the LAG function approaches the input value over time. In formula (12), another function whose output value approaches the input value over time can be used instead of the LAG function. The same applies to formula (13), which will be described later.

[0079] In formula (12), during the stationary time or phase, the value of the function LAG is the first temperature T1T f and the turbine inlet temperature estimate T1T e becomes equal to the second temperature T1T t . Consequently, the turbine inlet temperature estimate T1T e can be estimated with high accuracy during the stationary phase.

[0080] Furthermore, in formula (12), during the transition phase, a delay in the change of the value of the function LAG occurs and the change of the first temperature T1T f is included in the turbine inlet temperature estimate T1T e Consequently, the response of the turbine inlet temperature estimate T1T e be ensured during the transition phase.

[0081] In this way, when the correction unit 293 estimates the turbine inlet temperature estimation value using the formula (12), responsiveness of estimating the turbine inlet temperature can be ensured and the estimation accuracy can be improved.

[0082] Alternatively, the correction unit 293 may adjust the turbine inlet temperature estimate T1T e based on formula (13). [Math. 13] T1Te=T1Tf×T1TtLAG(T1Tf)

[0083] In formula (13), during the stationary phase, the value of the function LAG is the first temperature T1T f and the turbine inlet temperature estimate T1T e equal to the second temperature T1T t . Consequently, the turbine inlet temperature estimate T1T e can be estimated with higher accuracy during the stationary phase.

[0084] Furthermore, in formula (13), during the transition phase, a delay in the change of the value of the function LAG occurs and the change of the first temperature T1T f is included in the turbine inlet temperature estimate T1T e Consequently, the response of the turbine inlet temperature estimate T1T e be ensured during the transition phase.

[0085] In this way, when the correction unit 293 corrects the turbine inlet temperature estimate T1T e using formula (13), a responsiveness of the turbine inlet temperature estimation can be ensured and the estimation accuracy can be improved.

[0086] Alternatively, the correction unit 293 may adjust the turbine inlet temperature estimate T1T e based on formula (14). [Math. 14] T1Te=T1Tf+LAG(T1Tt−T1Tf)

[0087] In formula (14), during the stationary phase, the value of the function LAG is a value obtained by subtracting the first temperature T1T f from the second temperature T1T t ("T1T t -T1T f “) is obtained and the turbine inlet temperature estimate T1T e becomes equal to the second temperature T1T t . Consequently, the turbine inlet temperature estimate T1T e can be estimated with higher accuracy during the stationary phase.

[0088] Furthermore, in formula (14), during a phase of the transition, a delay in the change of the value of the function LAG occurs and the change of the first temperature T1T f is included in the turbine inlet temperature estimate T1T e Consequently, the response of the turbine inlet temperature estimate T1T e be ensured during a transition phase.

[0089] In this way, when the correction unit 293 corrects the turbine inlet temperature estimate T1T e using formula (14), the response of the turbine inlet temperature can be ensured and the estimation accuracy can be improved.

[0090] Alternatively, the correction unit 293 may adjust the turbine inlet temperature estimate T1T e based on formula (15). [Math. 15] T1Te=T1Tf×LAG(T1TtT1Tf)

[0091] "LAG (T1T t / T1T f )” of the formula (15) corresponds to an example of the correction coefficient determined based on the ratio of the first temperature to the second temperature.

[0092] In formula (15), during a stationary phase, the value of the function LAG is a value (“T1T t / T1T f “), which is calculated by dividing the second temperature T1T t by the first temperature T1T fis obtained, and the turbine inlet temperature estimate T1T e becomes equal to the second temperature T1T t . Consequently, the turbine inlet temperature estimate T1T e can be determined with higher accuracy during the stationary phase.

[0093] Furthermore, in formula (15), during a phase of the transition, a delay in the change of the value of the function LAG occurs and the change of the first temperature T1T f is included in the turbine inlet temperature estimate T1T e Consequently, the response of the turbine inlet temperature estimate T1T e be ensured during the transition phase.

[0094] In this way, when the correction unit 293 corrects the turbine inlet temperature estimate T1T eusing the formula (15), the response for estimating the turbine inlet temperature can be ensured and the estimation accuracy can be improved.

[0095] Next, the operation of the gas turbine control device 200 will be described with reference to Fig. 7 described. Fig. 7 is a diagram illustrating an example of a process flow in which the gas turbine control device 200 obtains a turbine inlet temperature estimate. The gas turbine control device 200 repeats the process of Fig. 7 for example at predetermined intervals.

[0096] In the example from Fig. 7, the first estimation unit 291 calculates the first temperature using the first model (step S111). Furthermore, the second estimation unit 292 calculates a second temperature using the second model (step S121). The first estimation unit 291 and the second estimation unit 292 can perform the process of step S111 and the process of step S121 in parallel or sequentially.

[0097] The correction unit 293 corrects the first temperature obtained in step S111 based on the second temperature obtained in step S121 (step S131).

[0098] After step S131, the process ends Fig. 7.

[0099] As described above, the first estimation unit 291 estimates the first temperature T1T f, which is a turbine inlet temperature estimate based on the first model, which is a physical model using the fuel flow rate to the gas turbine 110. The second estimation unit 292 estimates a second temperature T1Tt, which is a turbine inlet temperature estimate based on a second model, which is a physical model using the exhaust gas temperature of the gas turbine 110. The correction unit 293 corrects the first temperature based on the second temperature to obtain the turbine inlet temperature estimate T1T e to calculate.

[0100] In the gas turbine control device 200, the response of the turbine inlet temperature estimate T1T e be ensured by setting the first temperature T1T f based on the fuel flow rate. Furthermore, in the gas turbine control device 200, the turbine inlet temperature estimate T1T ecan be estimated with high accuracy by calculating the second temperature T1T t based on the exhaust gas temperature.

[0101] In this way, according to the gas turbine control device 200, a responsiveness for estimating the turbine inlet temperature can be ensured and the estimation accuracy can be improved.

[0102] Furthermore, it is not necessary since the second temperature T1T t in the turbine inlet temperature estimate T1T e by correcting the first temperature T1T freflected by the correction unit 293, switching the process between the stationary time or phase and the transient time or phase. This can avoid a sudden change in the estimated value that accompanies the switching of the process. In addition, because it is not necessary to determine whether the process is stationary or transient and it is not necessary to switch the process, the load on the control unit 290 can be reduced.

[0103] For example, the first estimation unit 291 estimates the first temperature based on the first model indicating the heat balance in the combustor 114. The second estimation unit 292 estimates the second temperature based on the second model indicating the heat balance using the exhaust gas temperature of the turbine 115. The correction unit 293 corrects the first temperature using the correction coefficient determined based on a ratio of the first temperature to the second temperature.

[0104] Thus, according to the gas turbine control device 200 as described above, responsiveness for estimating the turbine inlet temperature can be ensured and estimation accuracy can be improved. Furthermore, according to the gas turbine control device 200 as described above, it is not necessary to switch the process between the steady-state time or phase and the transient time or phase, and a sudden change in the estimated value accompanying the process switching can be avoided. Furthermore, because it is not necessary to determine whether the process is steady-state or transient and it is not necessary to switch the process, the load on the control unit 290 can be reduced. Embodiment

[0105] The gas turbine control device can correct the estimated value to be input to the first model. This will be described in the embodiment.

[0106] Fig. 8 is a schematic block diagram illustrating a functional configuration of a gas turbine control device according to an embodiment. As shown in Fig. As shown in Figure 8, the gas turbine control device 300 includes a communication unit 210, an operation input unit 220, a display unit 230, a storage unit 280, and a control unit 390. The control unit 390 includes a first estimation unit 291, a second estimation unit 292, a correction unit 293, and an input value correction unit 394.

[0107] Among the respective units from Fig. 8 are parts that belong to the respective units of Fig. 3 and have the same functions, are denoted by the same reference numerals (210, 220, 230, 280, 291, 292, and 293), and the description thereof is omitted. The gas turbine control device 300 according to the invention differs from the case of the gas turbine control device 200 in that the control unit 390 includes the input value correction unit 394. Otherwise, the gas turbine control device 300 is the same as that of the case of the gas turbine control device 200. In the embodiment of Fig. 1, the gas turbine control device 300 may be used instead of the gas turbine control device 200.

[0108] The input value correction unit 394 corrects at least one of the estimated values ​​to be input to the first model using the estimated value obtained by the calculation using the second model.

[0109] Among the values ​​to be input to the first model, the values ​​obtained by calculation, such as the fuel flow rate and the air flow rate, may contain errors relative to the actual values. As in the case of the turbine inlet temperature, the values ​​obtained in the calculation process of the second model are assumed to have higher accuracy during the steady-state period or phase than those input to the first models.

[0110] Therefore, the input value correction unit 394 performs a correction that reflects the value obtained in the calculation process of the second model for the stationary time or phase also in the value to be input to the first model, as described for the correction of the turbine inlet temperature.

[0111] Thus, in the gas turbine control device 300, the estimation accuracy of the turbine inlet temperature can be further improved.

[0112] Next, the operation of the gas turbine control device 300 will be described with reference to Fig. 9 described. Fig. 9 is a diagram illustrating an example of a process flow in which the gas turbine control device 300 calculates a turbine inlet temperature estimate. The gas turbine control device 300 repeats the process of Fig. 7 for example at predetermined intervals.

[0113] In the example from Fig. 9, the input value correction unit 394 corrects at least one of the estimated values ​​to be input to the first model using the estimated value obtained by the calculation using the second model (step S211).

[0114] Steps S212, S221 and S231 are respectively the same as steps S111, S121 and S131 of Fig. 7. After step S231, the process ends Fig. 9.

[0115] As described above, the input value correction unit 394 corrects at least one of the estimated values ​​to be input to the first model using the estimated value obtained by calculation using the second model.

[0116] In this way, in the gas turbine control device 300, the estimation accuracy of the turbine inlet temperature can be further improved.

[0117] In each of the example for convenience of understanding and the embodiment, a computer that performs the operation of the first estimation unit 291 and a computer that performs the operation of the second estimation unit 292 may be the same computer or may be separate computers.

[0118] It is assumed that the calculation of the first temperature using the first model does not require repeated calculation and the operation load is relatively small.

[0119] In contrast, in the case of calculating the second temperature using the second model, the operation load is assumed to be relatively large because it involves repetitive calculations. Therefore, when the operation of the second estimation unit 292 is executed using a normal control device, there is a possibility that the calculation may not be completed within the control phase.

[0120] Therefore, a computer for executing the operation of the second estimation unit 292 may be provided separately from the control device, and the second temperature calculated by the computer may be input to the correction unit 293.

[0121] Furthermore, by recording a program for realizing all or part of the functions of the control unit 290 or 390 on a computer-readable recording medium, and having the computer system read the program recorded on the recording medium and execute the program, the processing of each unit can be performed. Here, the "computer system" mentioned here includes an operating system and hardware such as peripheral devices.

[0122] The “computer system” also includes a homepage, which, when using a WWW system, provides an environment (or display environment).

[0123] The "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM or a CD-ROM, or a storage device such as a hard disk built into a computer system. The aforementioned program may be used to implement some of the functions described above, or it may be implemented in combination with the program in which the functions described above have already been recorded in the computer system.

[0124] The embodiments of the present invention have been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like within the scope of the present invention are also included.

[0125] An embodiment of the present invention relates to a gas turbine control device including a first estimation unit configured to estimate a first temperature that is a turbine inlet temperature estimate based on a first model that is a physical model using a fuel flow rate to a gas turbine, a second estimation unit configured to estimate a second temperature that is a turbine inlet temperature estimate based on a second model that is a physical model using an exhaust gas temperature of the gas turbine, and a correction unit configured to correct the first temperature based on the second temperature to calculate a turbine inlet temperature estimate.

[0126] According to this embodiment, the responsiveness in estimating the turbine inlet temperature can be ensured and the estimation accuracy can be improved. List of reference symbols: 1 gas turbine plant 100 plant main bodies 110 gas turbine 111 Inlet guide vane 112 compressors 113 housings 114 Combustion chamber 115 turbines 116 Rotating shaft 120 Generator 200, 300 gas turbine control device 210 Communication unit 220 Actuator input unit 230 display unit 280 storage units 290, 390 control unit 291 first estimation unit 292 second estimation unit 293 Correction unit 394 Input value correction unit

Claims

[1] A gas turbine control device (300) comprising: a first estimation unit (291) configured to estimate a first temperature (T1T f ) which is a first turbine inlet temperature estimate based on a first model which is a physical model using a fuel flow rate to a gas turbine (110), a second estimation unit (292) configured to determine a second temperature (T1T t ) which is a second turbine inlet temperature estimate based on a second model which is a physical model using an exhaust gas temperature of the gas turbine (110), an input value correction unit (394) configured to correct an estimated value to be input into the first model using an estimated value obtained by the calculation using the second model, and a correction unit (293) configured to correct the first temperature (T1T f ) based on the second temperature (T1T t ) by using a delay element to calculate a corrected turbine inlet temperature estimate such that the corrected turbine inlet temperature estimate during a steady-state phase of the gas turbine (110) is equal to the second temperature (T1T t ) becomes. [2] The gas turbine control device (300) according to claim 1, wherein the estimated value obtained by the calculation using the second model is an estimated value during a stationary phase of the gas turbine (110). [3] The gas turbine control device (300) according to claim 2, wherein the estimated value to be input into the first model is an estimated value of the fuel flow rate or an estimated value of an air flow rate. [4] The gas turbine control device (300) according to any one of claims 1 to 3, wherein the first estimation unit (291) estimates the first temperature (T1T f ) on the basis of the first model, which indicates a heat equilibrium in a combustion chamber (114), the second estimation unit (292) the second temperature (T1T t ) based on the second model which indicates a heat balance using an exhaust gas temperature of the gas turbine (110), and the correction unit (293) the first temperature (T1T f ) using a correction coefficient (X) calculated on the basis of a relationship between the first temperature (T1T f ) and the second temperature (T1T t ) is corrected. [5] A gas turbine plant (1) comprising the gas turbine control device (300) according to one of claims 1 to 4. [6] A gas turbine control method comprising: Estimating a first temperature (T1T f ), which is a first turbine inlet temperature estimate based on a first model, which is a physical model using a fuel flow rate to a gas turbine (110), Estimating a second temperature (T1T t ), which is a second turbine inlet temperature estimate based on a second model, which is a physical model using an exhaust gas temperature of the gas turbine (110), Correcting an estimate to be input into the first model using an estimate obtained by a calculation using the second model, and Correcting the first temperature (T1T f ) based on the second temperature (T1T t) by using a delay element to calculate a corrected turbine inlet temperature estimate such that the corrected turbine inlet temperature estimate during a steady-state phase of the gas turbine (110) is equal to the second temperature (T1T t ) becomes.

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