JP2019052586A - Compressor control device - Google Patents

Abstract

To reduce the possibility that an abnormal measurement value is used to perform control.SOLUTION: A compressor control device 26 is a device for controlling a compressor 2 on the basis of a measurement value VSV_A and a measurement value VSV_B of two displacement sensors for measuring an opening degree of a variable stator vane of the compressor 2, calculates an estimated opening degree that is an estimated value of the opening degree of the variable stator vane on the basis of an outlet pressure Pout of the compressor 2 and a rotation speed N of the compressor 2, selects a measurement value close to the estimated opening degree out of the measurement value VSV_A and the measurement value VSV_B, and uses the selected measurement value to control the compressor 2.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a compressor control device.

  2. Description of the Related Art Conventionally, there has been known a control device that measures the opening of a variable mechanism such as a variable stator blade by a sensor and performs predetermined control using the measured opening. For example, Patent Document 1 describes a control device that calculates the flow rate of air flowing into a combustor using a variable stator blade opening measured by a variable stator blade opening measuring instrument as an argument.

JP 2011-38478 A

  In order to increase the reliability of process control, the sensor may be duplicated. For example, in the technique described in Patent Document 1, when the variable stationary blade opening degree measuring device (sensor) is duplicated, when the measured values of the two sensors are in good agreement (normally), the two sensors When the difference between the measured values of the two sensors is large (when abnormal), it is determined that one of the measured values of the two sensors is abnormal and one is selected. It is possible. In the selection of the measurement value at the time of abnormality, the designer decides in advance whether to select a large value or a small value in consideration of fail-safe. However, even if the measurement value at the time of abnormality is selected by a predetermined selection method, the selected measurement value is not always a normal value. In such a case, if the control is performed using the selected measurement value, there is a possibility that a failure of the device, an emergency stop, or the like may occur.

  The present disclosure describes a compressor control device that can reduce the possibility of control using abnormal measurement values.

  A compressor control device according to an aspect of the present disclosure controls a compressor based on first measurement values and second measurement values of two displacement sensors for measuring the opening of a variable mechanism of the compressor. Device. The compressor control device calculates an estimated opening that is an estimated value of the opening of the variable mechanism based on the outlet pressure of the compressor and the rotation speed of the compressor, and the first measured value and the second measured value. Among these, a measured value close to the estimated opening is selected, and the compressor is controlled using the selected measured value.

  According to this indication, possibility that control will be performed using an abnormal measurement value can be reduced.

FIG. 1 is a diagram illustrating a schematic configuration of a gas turbine system including a compressor control device according to an embodiment. FIG. 2 is a diagram illustrating a schematic configuration of the compressor. FIG. 3 is a diagram showing the relationship between the corrected rotation speed and the pressure ratio. FIG. 4 is a flowchart showing a series of processes of the measurement value determination method for control performed by the compressor control device. FIG. 5 is a diagram illustrating an example of temporal changes in measured values and target values in the compressor illustrated in FIG. 1. FIG. 6 is a diagram illustrating an example of temporal changes in measured values and target values in the compressor of the comparative example.

[1] Outline of Embodiment The compressor control device according to one aspect of the present disclosure is based on the first measurement value and the second measurement value of the two displacement sensors for measuring the opening degree of the variable mechanism of the compressor. This is a device for controlling the compressor. The compressor control device calculates an estimated opening that is an estimated value of the opening of the variable mechanism based on the outlet pressure of the compressor and the rotation speed of the compressor, and the first measured value and the second measured value. Among these, a measured value close to the estimated opening is selected, and the compressor is controlled using the selected measured value.

  In this compressor control device, the estimated opening of the variable mechanism is calculated based on the outlet pressure of the compressor and the rotational speed of the compressor. Then, a measurement value close to the estimated opening is selected from the first measurement value and the second measurement value, and the compressor is controlled using the selected measurement value. Since both the first measurement value and the second measurement value are values obtained by measuring the opening of the variable mechanism of the compressor, they are essentially the same value, but either the first measurement value or the second measurement value. May become an abnormal value. Even in such a case, the measurement value close to the estimated opening degree among the first measurement value and the second measurement value is likely to be a normal value. For this reason, it becomes possible to reduce possibility that control will be performed using an abnormal measured value by selecting a measured value near the presumed opening among the 1st measured value and the 2nd measured value.

  The compressor control device is configured to determine an opening target value based on a change amount of the outlet pressure with respect to a reference pressure that is an outlet pressure at a reference time and a change amount of the rotation speed with respect to the reference rotation speed that is a rotation number at the reference time. An estimated opening degree may be calculated based on the opening degree target value and the deviation amount. The estimated opening degree can be calculated by such calculation.

  The compressor control device may acquire each of the first measurement value, the second measurement value, the outlet pressure, and the rotation speed at predetermined time intervals, and a difference between the first measurement value and the second measurement value is obtained. The reference pressure may be updated based on the outlet pressure, and the reference rotational speed may be updated based on the rotational speed when it is smaller than a predetermined threshold. When the difference between the first measurement value and the second measurement value is smaller than the threshold value, both the first measurement value and the second measurement value are considered to be normal values. In this case, since the compressor is controlled at a normal value, the outlet pressure and the rotation speed during normal operation can be acquired. By the way, the relationship between the outlet pressure and the rotational speed can gradually change over time due to the change in performance over time due to the contamination of the compressor and the like. However, in a short time range, the relationship between the outlet pressure and the rotational speed is kept almost constant. Therefore, by updating the reference pressure and reference rotation speed at predetermined time intervals based on the outlet pressure and rotation speed during normal operation, performance changes over time due to compressor contamination etc. can be used to calculate the estimated opening. The influence exerted can be reduced. Thereby, since the calculation accuracy of the estimated opening degree is improved, the selection accuracy of the measurement value can be improved.

  The compressor control device may stop the update of the reference pressure and the reference rotation speed when the difference between the first measurement value and the second measurement value is larger than a threshold value. When the difference between the first measurement value and the second measurement value is larger than the threshold value, either the first measurement value or the second measurement value is considered to be an abnormal value. In this case, since the compressor may be controlled with an abnormal value, an abnormal outlet pressure and rotation speed can be acquired. For this reason, by stopping the update of the reference pressure and the reference rotation speed, the estimated opening degree is calculated based on the outlet pressure and the rotation speed during normal operation. Thereby, since the calculation accuracy of the estimated opening degree is improved, the selection accuracy of the measurement value can be improved.

  When the difference between the first measurement value and the second measurement value is larger than a predetermined threshold, the compressor control device measures the estimated opening degree of the first measurement value and the second measurement value. A value may be selected and the compressor may be controlled using the selected measurement value. In this case, since the difference between the first measurement value and the second measurement value is larger than the threshold value, either the first measurement value or the second measurement value is considered to be an abnormal value. Therefore, by selecting a measurement value close to the estimated opening degree from the first measurement value and the second measurement value, it is possible to reduce the possibility that control is performed using an abnormal measurement value.

  The outlet pressure may be a ratio to the compressor inlet pressure. In this case, the estimated opening is calculated in consideration of the inlet pressure. For this reason, since the calculation accuracy of the estimated opening degree is improved, the measurement value selection accuracy can be improved.

  The rotation speed may be a corrected rotation speed corrected based on the inlet temperature of the compressor. In this case, the influence of the state of air flowing into the compressor is reduced. For this reason, since the calculation accuracy of the estimated opening degree is improved, the measurement value selection accuracy can be improved.

[2] Examples of Embodiments Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a diagram illustrating a schematic configuration of a gas turbine system including a compressor control device according to an embodiment. FIG. 2 is a diagram illustrating a schematic configuration of the compressor. A gas turbine system 1 shown in FIG. 1 is a two-shaft gas turbine system. The gas turbine system 1 includes a compressor 2, a combustor 3, a high pressure turbine 4, a low pressure turbine 5, a generator 6, a rotating shaft 7, and a rotating shaft 8.

  The compressor 2 generates compressed air by compressing the inflowing air. The compressor 2 supplies compressed air to the combustor 3. The detailed configuration of the compressor 2 will be described later. The combustor 3 burns by mixing fuel with the compressed air supplied from the compressor 2. The combustor 3 supplies a high-temperature and high-pressure combustion gas obtained by combustion to the high-pressure turbine 4. The high-pressure turbine 4 is rotated by the high-temperature and high-pressure combustion gas supplied from the combustor 3 and rotates the rotating shaft 7. The rotary shaft 7 connects the compressor 2 and the high-pressure turbine 4 so as to be integrally rotatable about the axis AX. The low pressure turbine 5 is rotated by the combustion gas that has passed through the high pressure turbine 4 and rotates the rotating shaft 8. The rotary shaft 8 is rotatable around the axis AX, and connects the low-pressure turbine 5 and the generator 6. The generator 6 is driven by the rotation of the rotating shaft 8.

  As shown in FIG. 2, the compressor 2 is an axial flow compressor. The compressor 2 includes a rotating body 21, a housing 22, a moving blade 23, a variable stator vane (VSV) 24, an actuator 25, and a compressor control device 26. The rotating body 21 is connected to the rotating shaft 7 and is rotatable around the axis AX. A rotor blade 23 is fixed to the outer peripheral surface of the rotating body 21. The housing 22 is a cylindrical housing and covers the rotating body 21 and the moving blade 23 around the axis AX. A variable stationary blade 24 is attached to the housing 22 in front of the moving blade 23 in the axis AX direction. The amount of air flowing into the compressor 2 is adjusted by adjusting the opening of the variable stationary blade 24. 2 shows a set of one moving blade 23 and one variable stationary blade 24, a plurality of sets of moving blades 23 and variable stationary blades 24 are provided along the axis AX direction. .

  The actuator 25 receives an opening / closing instruction (control signal) from the compressor control device 26, and adjusts the opening of the variable stationary blade 24 in accordance with the opening / closing instruction. For example, torque motor current is used as the opening / closing instruction.

  The compressor 2 includes a plurality of sensors for measuring each physical parameter of the compressor 2. The plurality of sensors include, for example, a displacement sensor, a temperature sensor, a pressure sensor, and a rotation speed sensor. The displacement sensor measures the opening degree of the variable stationary blade 24. The compressor 2 includes two displacement sensors. The two displacement sensors are provided in the actuator 25 and output measured values VSV_A and VSV_B indicating the opening degree of the variable stationary blade 24 to the compressor control device 26. The measured values VSV_A and VSV_B indicate that the opening degree of the variable stationary blade 24 is increased as it increases. The measured values VSV_A and VSV_B can take values from 0% (closed state) to 100% (fully open state).

  The temperature sensors are respectively provided at the inlet and the outlet of the compressor 2. The temperature sensor provided at the inlet of the compressor 2 measures the inlet temperature Tin of the compressor 2 and outputs the inlet temperature Tin to the compressor controller 26. The temperature sensor provided at the outlet of the compressor 2 measures the outlet temperature Tout of the compressor 2 and outputs the outlet temperature Tout to the compressor control device 26. The pressure sensors are respectively provided at the inlet and the outlet of the compressor 2. The pressure sensor provided at the inlet of the compressor 2 measures the inlet pressure Pin of the compressor 2 and outputs the inlet pressure Pin to the compressor controller 26. The pressure sensor provided at the outlet of the compressor 2 measures the outlet pressure Pout of the compressor 2 and outputs the outlet pressure Pout to the compressor control device 26. The rotational speed sensor measures the rotational speed N of the compressor 2 and outputs the rotational speed N to the compressor control device 26.

  The compressor control device 26 is a controller that controls the compressor 2. The compressor controller 26 includes a central processing unit (CPU), a random access memory (RAM) and a read only memory (ROM) that are main storage devices, a communication module that performs communication with other devices, a hard disk, and the like. The computer is configured with hardware such as an auxiliary storage device. When these components operate, functions of a compressor control device 26 described later are exhibited.

  The compressor control device 26 controls the compressor 2 based on the measurement value VSV_A and the measurement value VSV_B. Specifically, the compressor control device 26 determines a control measurement value used for controlling the compressor 2 based on the measurement value VSV_A and the measurement value VSV_B. A method for determining the control measurement value will be described later. The compressor control device 26 calculates a corrected rotational speed NR from the rotational speed N and the inlet temperature Tin, and calculates a target value VSVdmd corresponding to the corrected rotational speed NR based on the schedule. The schedule is a map in which the corrected rotation speed NR and the target value VSVdmd are associated with each other.

The corrected rotation speed NR is a value obtained by converting the rotation speed N into a rotation speed in a standard atmospheric state, and is a value obtained by correcting the rotation speed N based on the inlet temperature Tin. The corrected rotational speed NR is calculated using the rotational speed N, the inlet temperature Tin, and the reference temperature Tref as shown in the equation (1). The reference temperature Tref is a predetermined temperature, for example, 288 Kelvin.

  The compressor control device 26 outputs an opening / closing instruction (control signal) for the variable stationary blade 24 to the actuator 25 using the target value VSVdmd and the control measurement value. For example, when the control measurement value is smaller than the target value VSVdmd, a control signal is output to the actuator 25 so that the opening degree of the variable stationary blade 24 increases (opens the variable stationary blade 24). When the control measurement value is larger than the target value VSVdmd, a control signal is output to the actuator 25 so that the opening degree of the variable stationary blade 24 is decreased (the variable stationary blade 24 is closed).

  Next, the characteristics of the compressor 2 will be described. FIG. 3 is a diagram showing the relationship between the corrected rotation speed and the pressure ratio. In the compressor 2, the pressure ratio PR of the compressor 2 is expressed as a curve with respect to the corrected rotational speed NR. However, in a narrow range of the corrected rotational speed NR, the pressure ratio PR is corrected rotational speed as shown in FIG. It can be approximated as a linear function of the number NR.

The pressure ratio PR is the ratio of the outlet pressure Pout of the compressor 2 to the inlet pressure Pin of the compressor 2 as shown in the equation (2).

When the relationship between the pressure ratio PR and the corrected rotational speed NR is approximated as a linear function, it is expressed by Expression (3). When the reference pressure ratio PRref and the reference correction rotational speed NRref are used, it can be expressed by Expression (4). The reference pressure ratio PRref is the pressure ratio PR at the reference time. The reference correction rotation speed NRref is the correction rotation speed NR at the reference time. The coefficient A is determined in advance by experiments or the like. The coefficient B in Expression (3) is obtained from Expression (4) by −A × NRref + PRref. The reference time is, for example, 5 seconds ago. The reference pressure ratio PRref may be, for example, a time average value for 5 seconds of the pressure ratio PR. The reference correction rotation speed NRref may be, for example, a 5-second time average value of the correction rotation speed NR.

  Here, when the opening degree of the variable stationary blade 24 changes while the compressor 2 is operating at the same corrected rotational speed NR, the pressure ratio PR changes according to the opening degree. For example, the opening degree of the variable stationary blade 24 may be deviated due to a reason that the measurement value for control is not an appropriate value. Specifically, when either the measurement value VSV_A or the measurement value VSV_B is an abnormal value, if the abnormal value is selected as the control measurement value, a deviation from the appropriate opening of the variable vane 24 occurs. . If the control of the compressor 2 is continued in this state, as shown in FIG. 3, the performance of the compressor 2 decreases from the characteristic C1 to the characteristic C2, so that the same rotational speed N (corrected rotational speed NR) as compared with the normal state. The pressure ratio PR at decreases. When the deviation of the opening degree of the variable stationary blade 24 is large, the gas turbine system 1 may fail or trip.

Factors that change the performance of the compressor 2 include dirt and damage on the blades as well as abnormal measurement values for control. However, when the difference (deviation) between the measured value VSV_A and the measured value VSV_B is large, either the measured value VSV_A or the measured value VSV_B is considered to be an abnormal value. Accordingly, if the performance change of the compressor 2 occurs, it can be considered that the abnormality in the measurement value for control is the main cause of the performance change of the compressor 2. That is, the pressure ratio PR can be expressed by Expression (5). Note that the change amount of the pressure ratio PR when the opening degree of the variable stationary blade 24 is shifted by the shift amount x can be expressed by C × x using the coefficient C. The deviation amount x indicates the deviation amount (%) of the opening from the target value VSVdmd, and takes a positive value when the variable stationary blade 24 is displaced in the opening direction, and in the direction in which the variable stationary blade 24 is closed. Takes a negative value if it is off. The coefficient C is determined in advance by experiments or the like.

  Next, a control measurement value determination method performed by the compressor control device 26 will be described. FIG. 4 is a flowchart showing a series of processes of the measurement value determination method for control performed by the compressor control device. The series of processing shown in FIG. 4 is repeatedly performed at predetermined time intervals (for example, every 0.01 seconds).

  First, the compressor control device 26 acquires a measurement value from each sensor (step S01). Specifically, the compressor control device 26 acquires the measured values VSV_A and VSV_B, the inlet pressure Pin, the outlet pressure Pout, the inlet temperature Tin, the outlet temperature Tout, and the rotation speed N. Then, the compressor control device 26 calculates the pressure ratio PR using Expression (2), and calculates the corrected rotational speed NR using Expression (1) (Step S02).

  Subsequently, the compressor control device 26 calculates a difference (absolute value of the difference) between the measurement value VSV_A and the measurement value VSV_B. Then, the compressor control device 26 compares the difference with the threshold value VSVth, and determines whether the difference is less than the threshold value VSVth over the period D (step S03). The period D is a continuous period from the time before the reference time (for example, 6 seconds before) to the present, and is determined in advance. The threshold value VSVth is a value that can determine that one of the measurement value VSV_A and the measurement value VSV_B is an abnormal value, and is determined in advance. When it is determined that the difference is less than the threshold value VSVth over the period D (step S03: YES), the compressor control device 26 calculates an average value of the measured value VSV_A and the measured value VSV_B (step S04). Then, the compressor control device 26 determines the average value as the control measurement value. In step S04, the compressor control device 26 may determine the higher one of the measurement value VSV_A and the measurement value VSV_B as the control measurement value in consideration of fail-safe.

  Then, the compressor control device 26 updates the reference pressure ratio PRref and the reference correction rotational speed NRref (step S05). Specifically, the compressor control device 26 sets the pressure ratio PR calculated in step S02 as the reference pressure ratio PRref, and sets the corrected rotation speed NR calculated in step S02 as the reference corrected rotation speed NRref. In this way, a series of processes of the control measurement value determination method is completed.

  On the other hand, when it is determined in step S03 that the difference is equal to or greater than the threshold value VSVth even during the period D (step S03: NO), the reference pressure ratio PRref and the reference correction rotational speed NRref are fixed. (Step S06). That is, as long as the difference is equal to or greater than the threshold value VSVth, the reference pressure ratio PRref and the reference correction rotation speed NRref are not updated.

Subsequently, the compressor control device 26 calculates an estimated opening degree VSVest (step S07). The estimated opening degree VSVest is an estimated value of the opening degree of the variable stationary blade 24. The compressor control device 26 calculates the estimated opening degree VSVest based on the outlet pressure Pout and the rotation speed N. Specifically, the compressor control device 26 calculates the deviation amount x of the variable stationary blade 24 using Expression (6) obtained by transforming Expression (5).

Then, the compressor control device 26 calculates the estimated opening degree VSVest using the equation (7). As shown in Expression (7), the estimated opening degree VSVest is a value obtained by adding a deviation amount x to the target value VSVdmd.

  And the compressor control apparatus 26 selects the measured value close | similar to the estimated opening degree VSVest among measured value VSV_A and measured value VSV_B (step S08). Then, the compressor control device 26 determines the selected measurement value as the control measurement value, and the series of processes of the control measurement value determination method ends. Note that the process of step S07 may be performed regardless of whether or not the difference between the measured value VSV_A and the measured value VSV_B is equal to or greater than the threshold value VSVth.

  Thus, when the difference between the measured value VSV_A and the measured value VSV_B is smaller than the threshold value VSVth, the compressor control device 26 controls the compressor 2 using the average value of the measured value VSV_A and the measured value VSV_B. Do. On the other hand, when the difference between the measurement value VSV_A and the measurement value VSV_B is larger than the threshold value VSVth (in this embodiment, the difference is equal to or greater than the threshold value VSVth), the compressor control device 26 measures the measurement value VSV_A and the measurement value VSV_B. Among these, a measured value close to the estimated opening degree VSVest is selected, and the compressor 2 is controlled using the selected measured value. Note that the estimated opening degree VSVest is not used for controlling the compressor 2 because the accuracy is low.

  The compressor control device 26 calculates a deviation amount x from the target value VSVdmd based on the change amount of the pressure ratio PR with respect to the reference pressure ratio PRref and the change amount of the correction rotation speed NR with respect to the reference correction rotation speed NRref. The estimated opening degree VSVest is calculated based on the target value VSVdmd and the deviation amount x. When the difference between the measured value VSV_A and the measured value VSV_B is smaller than the threshold value VSVth, the compressor control device 26 updates the reference pressure ratio PRref with the pressure ratio PR, and updates the reference corrected rotational speed NRref with the corrected rotational speed NR. To do. On the other hand, when the difference between the measured value VSV_A and the measured value VSV_B is larger than the threshold value VSVth (in this embodiment, the difference is equal to or greater than the threshold value VSVth), the compressor control device 26 determines the reference pressure ratio PRref and the reference value. Update of the corrected rotation speed NRref is stopped.

  Next, with reference to FIG.5 and FIG.6, the effect of the compressor control apparatus 26 is demonstrated. FIG. 5 is a diagram illustrating an example of temporal changes in measured values and target values in the compressor illustrated in FIG. 1. FIG. 6 is a diagram illustrating an example of temporal changes in measured values and target values in the compressor of the comparative example. In the example shown in FIGS. 5 and 6, the measured value VSV_A becomes an abnormal value at time t1, and the difference between the measured value VSV_A and the measured value VSV_B is larger than the threshold value VSVth.

  The compressor of the comparative example is different from the compressor 2 in that the higher one of the measurement value VSV_A and the measurement value VSV_B is used as the control measurement value regardless of the difference between the measurement value VSV_A and the measurement value VSV_B. doing. For this reason, in the compressor of the comparative example, the measurement value VSV_A is used as the control measurement value at time t1. At this time, since the control measurement value is larger than the target value VSVdmd, the compressor control device 26 decreases the opening of the variable stator blade 24 by a value obtained by subtracting the target value VSVdmd from the control measurement value (variable stator blade). A control signal is output to the actuator 25 so as to close (24).

  As a result, as shown in FIG. 6, the measured value VSV_A and the measured value VSV_B both decrease after time t1. However, the measurement value VSV_A is an abnormal value, and the measurement value VSV_B is a normal value. That is, the measured value VSV_B indicates the opening of the variable stator blade 24, and the actual opening of the variable stator blade 24 is smaller than the target value VSVdmd. As a result, since the outlet pressure Pout (pressure ratio PR) decreases, the compressor control device 26 increases the rotational speed N (corrected rotational speed NR) in order to maintain the performance. Then, the compressor control device 26 calculates a target value VSVdmd corresponding to the changed corrected rotational speed NR based on the schedule. As a result, the target value VSVdmd increases.

  On the other hand, as shown in FIG. 5, in the compressor 2, when the measured value VSV_A becomes an abnormal value at time t1, and the difference between the measured value VSV_A and the measured value VSV_B is larger than the threshold value VSVth, the measured value VSV_A and the measured value are measured. Of the value VSV_B, a measurement value close to the estimated opening degree VSVest is used as a control measurement value. For this reason, the measured value VSV_B and the target value VSVdmd are constant values with almost no change after time t1.

  In the compressor 2, immediately after the time t1, the measurement value VSV_A is temporarily used as a control measurement value due to the influence of the response speed of the sensor or the like. For this reason, similarly to the compressor of the comparative example, both the measured value VSV_A and the measured value VSV_B decrease, and the target value VSVdmd increases. However, when the measurement value VSV_B is used as the control measurement value by the estimated opening degree VSVest, the measurement value VSV_B and the target value VSVdmd return to the original values. As a result, the actual opening of the variable stator blade 24 is maintained at the target value VSVdmd, so that an increase in the rotational speed N and inappropriate control of the variable stator blade 24 can be avoided, and the compressor 2 may break down. Can be reduced.

  As described above, the compressor control device 26 calculates the estimated opening degree VSVest of the variable stationary blade 24 based on the outlet pressure Pout of the compressor 2 and the rotational speed N of the compressor 2. Specifically, the estimated opening degree VSVest is calculated based on the pressure ratio PR, which is the ratio of the outlet pressure Pout to the inlet pressure Pin, and the corrected rotational speed NR obtained by correcting the rotational speed N based on the inlet temperature Tin. The Then, a measurement value close to the estimated opening degree VSVest is selected from the measurement value VSV_A and the measurement value VSV_B, and the compressor 2 is controlled using the selected measurement value. The measured value VSV_A and the measured value VSV_B are both values obtained by measuring the opening of the variable stationary blade 24 of the compressor 2, and thus are originally the same value, but one of the measured value VSV_A and the measured value VSV_B is It may be an abnormal value. Even in such a case, the measurement value close to the estimated opening degree VSVest among the measurement value VSV_A and the measurement value VSV_B is likely to be a normal value. For this reason, it becomes possible to reduce a possibility that control will be performed using an abnormal measurement value by selecting a measurement value close to the estimated opening degree VSVest from the measurement value VSV_A and the measurement value VSV_B. As a result, it is possible to avoid damage to the gas turbine system 1 and occurrence of a trip without changing the operating state of the compressor 2.

  As shown in the equation (6), based on the change amount of the pressure ratio PR with respect to the reference pressure ratio PRref and the change amount of the corrected rotation speed NR with respect to the reference correction rotation speed NRref, the deviation amount x from the target value VSVdmd Is calculated, and the estimated opening degree VSVest is calculated based on the target value VSVdmd and the shift amount x as shown in the equation (7). The estimated opening degree VSVest can be calculated by such simple calculation.

  When the difference between the measured value VSV_A and the measured value VSV_B is larger than the threshold value VSVth, the compressor control device 26 selects and selects a measured value close to the estimated opening degree VSVest from the measured value VSV_A and the measured value VSV_B. The compressor 2 is controlled using the measured values. When the difference between the measurement value VSV_A and the measurement value VSV_B is larger than the threshold value VSVth, it is considered that one of the measurement value VSV_A and the measurement value VSV_B is an abnormal value. Therefore, in such a case, by selecting a measurement value close to the estimated opening degree VSVest from the measurement value VSV_A and the measurement value VSV_B, it is possible to reduce the possibility that control is performed using an abnormal measurement value. It becomes.

  When the difference between the measured value VSV_A and the measured value VSV_B is smaller than the threshold value VSVth, both the measured value VSV_A and the measured value VSV_B are considered to be normal values. In this case, since the compressor 2 is controlled at a normal value, the inlet pressure Pin, the outlet pressure Pout, and the rotation speed N during normal operation can be acquired. By the way, the relationship between the pressure ratio PR and the corrected rotational speed NR can be gradually changed over time due to the change in performance over time due to the contamination of the compressor 2 or the like. For this reason, even if a strict performance map between the pressure ratio PR and the corrected rotational speed NR is created, the relationship shown in the performance map is the relationship between the actual pressure ratio PR and the corrected rotational speed NR as time passes. It will not fit. However, in a short time range, the relationship between the pressure ratio PR and the corrected rotational speed NR is kept almost constant. Accordingly, the reference pressure ratio PRref is updated based on the outlet pressure Pout (pressure ratio PR) during normal operation at a predetermined time interval, and the reference correction rotational speed NRref is updated at a predetermined time interval at the rotational speed N (corrected rotational speed). By updating based on (NR), it is possible to reduce the influence of the change in performance over time due to dirt or the like of the compressor 2 on the calculation of the estimated opening degree VSVest. Further, since the reference pressure ratio PRref and the reference correction rotational speed NRref are calculated based on the actual operation data, the estimated opening degree VSVest suitable for the performance of the individual compressor 2 can be calculated. Thereby, since the calculation accuracy of the estimated opening degree VSVest is improved, the selection accuracy of the measurement value can be improved.

  When the difference between the measured value VSV_A and the measured value VSV_B is larger than the threshold value VSVth, the compressor 2 may be controlled with an abnormal value, and therefore, an abnormal inlet pressure Pin, outlet pressure Pout, and rotation speed N are acquired. obtain. For this reason, by stopping the update of the reference pressure ratio PRref and the reference correction rotation speed NRref, the estimated opening degree VSVest is calculated based on the pressure ratio PR and the correction rotation speed NR during normal operation. Thereby, since the calculation accuracy of the estimated opening degree VSVest is improved, the selection accuracy of the measurement value can be improved.

  Further, since the estimated opening degree VSVest is calculated in consideration of not only the outlet pressure Pout but also the inlet pressure Pin, the calculation accuracy of the estimated opening degree VSVest is improved. Further, since the estimated opening degree VSVest is calculated using the corrected rotational speed NR, the influence of the state of the air flowing into the compressor 2 is reduced. For this reason, the calculation accuracy of the estimated opening degree VSVest is improved. Therefore, the measurement value selection accuracy can be improved.

  As mentioned above, although embodiment of this indication was described, this invention is not limited to the said embodiment.

  In the above embodiment, the measurement value close to the estimated opening degree VSVest is selected from the two measurement values (measurement values VSV_A, VSV_B) from the duplicated displacement sensor, but this is not limitative. The number of multiplexed displacement sensors may be two or more, and a measurement value closest to the estimated opening VVSest is selected from N measurement values from N (an integer greater than or equal to 2) displacement sensors. .

  The compressor control device 26 selects a measured value close to the estimated opening degree VSVest from the measured value VSV_A and the measured value VSV_B regardless of whether or not the difference between the measured value VSV_A and the measured value VSV_B is larger than the threshold value VSVth. Then, the compressor 2 may be controlled using the selected measurement value.

  The control measurement value determination method can be applied to other than the measurement value of the opening degree of the variable stationary blade 24. For example, the control measurement value determination method can be applied to measurement values of the opening degree of the inlet guide vane (IGV) of the compressor 2 and the bleed valve of the compressor 2.

  In the above embodiment, the compressor 2 is a compressor of the two-shaft gas turbine system 1, but may be a compressor of a single-shaft gas turbine system.

  The compressor control device 26 may calculate the estimated opening degree VSVest in consideration of other items that may affect the pressure ratio PR. For example, compressor intercooling can be considered. In this case, a correction term is added to the right side of Equation (5).

  Since the estimated opening degree VSVest is calculated using an estimation formula (formula (6)) based on the performance when the state of each measurement value is settled, the rotation speed N and the outlet pressure used for the calculation are calculated. Due to the transient response of Pout, the estimated opening degree VSVest may become inaccurate immediately after the operation suddenly changes. Therefore, when the compressor control device 26 determines that the difference between the measured value VSV_A and the measured value VSV_B is less than the threshold value VSVth to the threshold value VSVth (detects occurrence of an abnormality), it operates a timer (not shown). Until a predetermined time elapses after detection of the occurrence of abnormality, the average value of the measurement value VSV_A and the measurement value VSV_B or the higher one of the measurement value VSV_A and the measurement value VSV_B is determined as the control measurement value. Also good. The predetermined time is a time during which the operating state is stabilized to some extent and each sensor (particularly, the pressure sensor and the rotation speed sensor provided at the outlet of the compressor 2) is considered to respond sufficiently. About seconds. Thereby, since the calculation accuracy of the estimated opening degree VSVest is improved, the possibility of selecting an abnormal measurement value from the measurement value VSV_A and the measurement value VSV_B can be reduced.

  The compressor control device 26 may calculate the estimated opening degree VSVest by another formula based on the performance of the compressor 2. For example, since the inlet pressure Pin can be considered to be constant, the outlet pressure Pout may be used instead of the pressure ratio PR. In this case, the outlet pressure Pout at the reference time is used instead of the reference pressure ratio PRref. Further, the rotation speed N may be used instead of the corrected rotation speed NR. In this case, the rotation speed N at the reference time is used instead of the reference correction rotation speed NRref.

DESCRIPTION OF SYMBOLS 1 Gas turbine system 2 Compressor 3 Combustor 4 High pressure turbine 5 Low pressure turbine 6 Generator 7 Rotating shaft 8 Rotating shaft 21 Rotating body 22 Housing 23 Rotor blade 24 Variable stationary blade (variable mechanism)
25 Actuator 26 Compressor Controller AX Axis

Claims (7)

A compressor control device that controls the compressor based on the first measurement value and the second measurement value of two displacement sensors for measuring the opening of the variable mechanism of the compressor,
Based on the outlet pressure of the compressor and the rotation speed of the compressor, an estimated opening that is an estimated value of the opening of the variable mechanism is calculated, and the first measured value and the second measured value are calculated. Among these, the compressor control apparatus which selects the measured value close | similar to the said estimated opening degree, and controls the said compressor using the selected measured value.   Based on the change amount of the outlet pressure with respect to the reference pressure that is the outlet pressure at the reference time and the change amount of the rotation speed with respect to the reference rotation speed that is the rotation speed at the reference time, the deviation amount from the target opening value is calculated. The compressor control device according to claim 1, wherein the estimated opening degree is calculated based on the opening degree target value and the deviation amount. Obtaining each of the first measurement value, the second measurement value, the outlet pressure, and the rotational speed at predetermined time intervals;
When the difference between the first measured value and the second measured value is smaller than a predetermined threshold, the reference pressure is updated based on the outlet pressure, and the reference rotational speed is based on the rotational speed. The compressor control device according to claim 2, wherein the compressor control device is updated.   The compressor control device according to claim 3, wherein when the difference between the first measurement value and the second measurement value is larger than the threshold value, the updating of the reference pressure and the reference rotation speed is stopped.   When the difference between the first measurement value and the second measurement value is larger than a predetermined threshold value, a measurement value close to the estimated opening degree is selected from the first measurement value and the second measurement value. The compressor control device according to any one of claims 1 to 4, wherein the compressor is selected and controlled using the selected measurement value.   The compressor control device according to any one of claims 1 to 5, wherein the outlet pressure is a ratio with respect to an inlet pressure of the compressor.   The compressor control device according to any one of claims 1 to 6, wherein the rotation number is a corrected rotation number corrected based on an inlet temperature of the compressor.

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