JP2005127203A - Control device for gas turbine facilities - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for gas turbine facilities capable of stably controlling various process quantities of a plant even at a time of variable load operation. <P>SOLUTION: The gas turbine facility consists of a compressor 2 compressing air, a combustor 3 burning fuel and air compressed by the compressor 2, a turbine 1 driven by combustion gas created in the combustor 3, a spray 8 supplying water in suction air of the compressor 2 or compressed air compressed by the compressor 2. A control device 30 changes water quantity supplied to compressed air when difference ΔMW between effective output MW of a generator 4 connected to the turbine 1 and an output target value MWD of a generator 4 exceeds a predetermined value. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control device for gas turbine equipment, and more particularly, to a gas turbine equipment that uses a spray for humidifying gas in a high-humidity gas turbine power plant that humidifies gas supplied to the gas turbine to improve output and efficiency. The present invention relates to a control device suitable for use.

  Recently, high-humidity gas turbine power plants that improve the output and efficiency by injecting moisture into the gas (air) supplied to the gas turbine will improve the power and efficiency of existing gas turbine power plants. In response to the need for a new introduction as a plant, a load followability comparable to that of a conventional gas turbine power plant is required.

  Therefore, various types of operation control methods for the fuel flow rate and the spray flow rate are known. For example, as described in Japanese Patent Application Laid-Open No. 2000-230432, when the plant load is changed by this control method. Is known that adjusts the humidity of the humidified air prior to the load change, and starts the plant load change after completion of the moisture adjustment.

JP 2000-230432 A

  However, in the thing of Unexamined-Japanese-Patent No. 2000-230432, when carrying out load operation of a high-humidity gas turbine, the humidity of humidified air is adjusted in advance and the fluctuation | variation of the process amount by spray spray is stabilized. However, there is a problem that the rapid load following operation which is desired for the high-humidity gas turbine is difficult in the operation in which the load operation is waited for.

  The objective of this invention is providing the control apparatus of the gas turbine equipment which can control various process quantities of a plant stably also at the time of load change operation.

(1) To achieve the above object, the present invention comprises a compressor for compressing air, a combustor for combusting air and fuel compressed by the compressor, and a combustion gas generated by the combustor. A control device for gas turbine equipment having a turbine to be driven and a water adding device for supplying water to intake air of the compressor or compressed air compressed by the compressor, and an effective output of a generator connected to the turbine And a control means for changing the amount of water supplied to the intake air or compressed air when the difference between the output target value of the generator exceeds a predetermined value.
With this configuration, various process amounts of the plant can be stably controlled even during load change operation.

  (2) To achieve the above object, the present invention comprises a compressor that compresses air, a combustor that combusts air and fuel compressed by the compressor, and a combustion gas generated by the combustor. A control device for gas turbine equipment, comprising: a turbine to be driven; and a water supply device for supplying water to intake air of the compressor or compressed air compressed by the compressor, wherein the control means includes exhaust gas from the turbine outlet When the difference between the temperature and the target value of the exhaust temperature exceeds a predetermined value, the amount of water supplied to the compressed air is changed.

  With this configuration, various process amounts of the plant can be stably controlled even during load change operation.

  (3) To achieve the above object, the present invention comprises a compressor that compresses air, a combustor that combusts air and fuel compressed by the compressor, and a combustion gas generated by the combustor. A control device for gas turbine equipment, comprising: a turbine to be driven; and a water supply device for supplying water to intake air of the compressor or compressed air compressed by the compressor, wherein the control means includes exhaust gas from the turbine outlet When the difference between the temperature and the maximum use temperature (alarm value) of the exhaust temperature exceeds a predetermined value, the amount of water supplied to the compressed air is changed.

  With this configuration, various process amounts of the plant can be stably controlled even during load change operation.

  (4) In the above (1) to (3), preferably, the water adding device has a plurality of on / off motor-operated valves and one proportional control valve, and the control means adjusts the opening of the proportional control valve. Accordingly, the on / off control valve is controlled to open and close.

  (5) In the above (1) to (3), preferably, the control means supplies fuel to the combustor based on a difference between an effective output of the generator and an output target value of the generator. The amount is controlled.

  (6) In the above (1) to (3), preferably, the water adding device is realized by a combination of a plurality of water injection nozzles.

  According to the present invention, various process amounts of a plant can be stably controlled even during load change operation.

Hereinafter, the configuration and operation of the control device for the gas turbine equipment according to the first embodiment of the present invention will be described with reference to FIGS. In this embodiment, a high-humidity gas turbine power plant will be described as an example of gas turbine equipment.
First, the system system of the high humidity gas turbine power plant according to the present embodiment will be described with reference to FIG.
FIG. 1 is a system diagram of a high humidity gas turbine power plant according to a first embodiment of the present invention.

  After the air used for gas turbine combustion is pressurized by the compressor 2, moisture is injected and humidified using the spray 8 installed in the pipe 7. Further, in order to completely evaporate moisture in the air, heating is performed by the low temperature side regenerative heat exchanger 11 and the high temperature side regenerative heat exchanger 12. The heat source of the heat exchangers 11 and 12 is exhaust gas from the gas turbine. As a result of the heating, the gas in the pipe 13 becomes a mixed fluid of air and steam.

  On the other hand, the fuel pressurized by the fuel pump 5 is combusted by the mixed fluid of air and steam previously obtained in the combustor 3. Combustion gas generated by combustion of fuel, air, and steam is discharged to the outside of the turbine through the flue 14 after driving the gas turbine 1. The thermal energy of the combustion gas (combustion exhaust gas) discharged outside the turbine is recovered by the high temperature side regenerative heat exchanger 12 and the low temperature side regenerative heat exchanger 11 and used for heating in the air. Further, water in the combustion exhaust gas is recovered by the water recovery device 15. The water recovery method is a method in which water is sprayed on the flue and the water in the gas is condensed and dropped to recover. The combustion exhaust gas after moisture recovery is discharged into the atmosphere using the chimney 16.

  The driving force obtained by the gas turbine 1 is transmitted to the compressor 2 and the generator 4 through the shaft 20. A part of the driving force is used for pressurization of air in the compressor 2. Further, the driving force is converted into electric power by the generator 4.

  The water recovered by the water recovery device 15 is stored in the water recovery tank 18 and supplied to the spray 8 and the water recovery device 15 by the pump 10, and humidified water to the spray 8 or spray to the water recovery device 15. Reuse as water. Moisture discharged from the chimney 16 to the atmosphere is supplemented by a makeup water pump 17.

  The control device 30 includes a power generation amount MW that is an effective output of the high-humidity gas turbine power plant, a power generation amount command MWD given from a central power supply command station, the spray number Ksp obtained from the spray control means 113, and the exhaust temperature of the turbine 1. A spray number command KspD is output to the spray control means 113 based on Tx, the outlet pressure PcD of the compressor 2, and the like. The spray control means 113 drives the on / off electric valve 9 based on the spray number command KspD given from the control device 30 to control the amount of water supplied to the spray 8. In the high-humidity gas turbine power plant, the flow rate of the combustion gas also changes depending on the humidification amount of the spray, and the power generation amount also changes at the same time. Therefore, it is necessary to appropriately control the spray 8 during plant load operation.

Next, the detailed configuration of the control device 30 used in the high humidity gas turbine power plant according to the present embodiment will be described with reference to FIG.
FIG. 2 is a functional block diagram showing a detailed configuration of the control device 30 used in the high humidity gas turbine power plant according to the first embodiment of the present invention.

  The control device 30 controls the spray flow rate from the power generation amount command MWD from the central power supply command station (medium supply), the output MW of the generator 4, the exhaust temperature Tx of the turbine 1, and the air pressure PcD at the outlet of the compressor 2. Details thereof will be described later with reference to FIG. Here, as a spray flow rate control method, spray number control is adopted in which the flow rate of the spray is adjusted by opening and closing at least two on / off motor-operated valves. If an on / off motorized valve is used for the spray, the spray flow rate may fluctuate abruptly when the valve is opened and closed, so the turbine exhaust temperature may change significantly.However, the motorized valve is generally much cheaper than the control valve, Further, since there is a merit that calibration work for flow rate adjustment is not required, it is suitable for use in cogeneration, IPP, and the like.

  The spray control circuit 30 includes three types of control circuits 30A, 30B, and 30C. The first control circuit 30A calculates the number of motor-operated valves operated at a constant plant load operation, and includes a spray number setting means 100, subtractors 103 and 104, and a constant operation spray increase / decrease setting means 107. I have.

  The spray number setting means 100 calculates the spray number setting value KspD according to the generator command MWD.

Here, a setting example of the spray number setting unit 100 will be described with reference to FIG.
FIG. 3 is an explanatory diagram of a setting example of the spray number setting means 100 of the control device 30 used in the high-humidity gas turbine power plant according to the first embodiment of the present invention. The horizontal axis in FIG. 3 indicates the power generation amount command value MWD (%), and the vertical axis indicates the spray number command value KspD (line).

  For example, as shown in FIG. 3, when the power generation amount command value MWD is 0%, the spray number command value KspD is zero. When the power generation amount command value MWD is greater than 0% and less than or equal to 12.5%, the spray number command value KspD is 1, and the power generation amount command value MWD is greater than 12.5% and less than 25%. In this case, the spray number command value KspD is increased by 2 in increments of 12.5%, such as two.

  Note that the number of spray injections at the partial load is set so that the plant efficiency at the partial load is maximized, but as a result of fluctuations in the balance of the plant due to the load change operation, the number of sprays after the load change is the spray number setting means. The number may be different from the number set to 100.

  The subtractor 104 obtains the current spray number deviation ΔKsp from the spray number setting value KspD and the current spray number Ksp. The subtractor 103 obtains a power generation amount deviation ΔMW from the generator output MW and the power generation amount command MWD.

  The constant operation spray increase / decrease setting means 107 determines the current plant operation state from the power generation amount deviation ΔMW and the generator command MWD. If the time change rate of the generator command MWD is zero (that is, the plant load is constant) and the absolute value of the time change rate ΔMW of the generator command MWD is within the set value, the plant is in steady operation. to decide. At this time, the constant operation spray increase / decrease setting means 107 calculates the constant operation spray increase / decrease setting signal ΔKls so that ΔKsp becomes zero when the spray number deviation ΔKsp is non-zero.

  The first control circuit 30A performs control so that the plant efficiency at the partial load is maximized by controlling the number of sprays to match the set value after the load change.

  The second control circuit 30B calculates the number of motor operated valves at the time of plant load change operation. The second control circuit 30B includes a turbine exhaust temperature setting means 101, a subtractor 105, and a load change operation spray increase / decrease setting means 108. I have.

  The turbine exhaust temperature setting means 101 obtains an exhaust temperature target value TxD from the power generation amount command value MWD.

Here, the example of a setting of the turbine exhaust temperature setting means 101 is demonstrated using FIG.
FIG. 4 is an explanatory diagram of a setting example of the turbine exhaust temperature setting means 101 of the control device 30 used in the high humidity gas turbine power plant according to the first embodiment of the present invention. The horizontal axis in FIG. 4 indicates the power generation amount command value MWD (%), and the vertical axis indicates the turbine exhaust temperature Tx (° C.).

  In FIG. 4, the thick solid line indicates the gas temperature target value TxD. Originally, the set value of the turbine exhaust temperature during constant load operation needs to be controlled as indicated by the dotted line in accordance with the change in the number of sprays, but in this embodiment, as shown by the thin solid lines TxDL and TxDU, An upper limit and a lower limit are provided, and the number of sprays is controlled when the turbine exhaust temperature deviation ΔTx deviates from the set value range (upper limit / lower limit range indicated by a thin solid line in the figure). This is because mutual interference with the fuel flow rate, which is the main operation amount of the power generation amount and the exhaust gas temperature control, is suppressed. Furthermore, the present embodiment aims at the effect of offsetting the temperature drop due to the spray injection by deviating the turbine exhaust temperature upward when the load is increased. Further, when the load is lowered, the turbine exhaust temperature is deviated downward to cancel out the temperature rise when the number of sprays is reduced. The upper limit and the lower limit of the set value in this embodiment are set from the temperature fluctuation range due to spray injection.

  In FIG. 2, the subtractor 105 subtracts the turbine exhaust temperature Tx and the exhaust temperature target value TxD obtained by the turbine exhaust temperature setting means 101 to obtain the exhaust temperature deviation ΔTx. When the exhaust temperature deviation ΔTx exceeds the set temperature difference, the load change operation spray increase / decrease setting means 108 increases the number of sprays as the load change spray increase / decrease setting value ΔKlf = + 1. When the exhaust temperature deviation ΔTx becomes negative and falls below the set temperature difference, the spray increase / decrease set value ΔKlf = −1 when the load changes, and the number of sprays is reduced.

  The turbine exhaust temperature Tx varies when the load changes. By making the variation of the exhaust temperature Tx within the set temperature difference, the generator output, the generator frequency, the turbine speed, and the like can be controlled more stably. As a result of the operation of the control circuit 30B, when the number of sprays after the load change is different from the planned value, the first control circuit corrects it to the planned value.

  The third control circuit 30C calculates the number of motor-operated valves operated in the event of a plant emergency, and includes a gas turbine exhaust temperature limiting means 200, a subtractor 106, and an exhaust gas temperature limited spray increase / decrease setting means 109. I have.

  In a plant emergency, for example, when abnormal combustion occurs in the combustor, the combustion temperature in the combustor rises, causing equipment troubles such as combustion nozzle melting and turbine blade damage. For such problems, conventional gas turbine control monitors the gas turbine exhaust temperature, and if the exhaust temperature exceeds the set temperature, the fuel flow control valve is closed to suppress the temperature rise in the combustor. ing. In the third control circuit 30C of the present embodiment, the temperature rise in the combustor is suppressed by the spray. In addition, although mass flow volume increases by spray injection, a load falls as a whole by the effect of a temperature fall.

  The turbine exhaust temperature limit value means 200 obtains the turbine exhaust temperature limit value TxLim from the compressor outlet pressure PcD.

Here, a setting example of the turbine exhaust temperature limit value means 200 will be described with reference to FIG.
FIG. 5 is an explanatory diagram of a setting example of the turbine exhaust temperature limit value means 200 of the control device 30 used in the high humidity gas turbine power plant according to the first embodiment of the present invention. The horizontal axis in FIG. 5 represents the compressor discharge pressure PcD (kPa), and the vertical axis represents the turbine exhaust temperature Tx (° C.).

  In general, it is empirically known that the gas temperature in the combustor is proportional to the compressor outlet pressure. Therefore, also in the present embodiment, the turbine exhaust temperature limit value means 200 obtains the alarm temperature TxLim of the exhaust temperature from the compressor outlet pressure PcD. In the figure, the solid line represents the alarm temperature and the trip temperature at the start of the load operation, and the broken line represents the alarm temperature and trip temperature at the start. In this embodiment, the turbine exhaust temperature limit value means 200 outputs the alarm temperature TxLim corresponding to the compressor outlet pressure PcD. To do.

  In FIG. 2, the subtractor 106 subtracts the turbine exhaust temperature Tx and the turbine exhaust temperature limit value TxLim obtained by the turbine exhaust temperature limit value means 200, and sets the exhaust gas temperature limit spray increase / decrease set value ΔTxLim. Ask for. When the exhaust gas temperature limit spray increase / decrease setting value ΔTxLim is 0 or a positive number, the exhaust gas temperature limit spray increase / decrease setting means 109 increases the number of sprays by setting the exhaust gas temperature limit spray increase / decrease setting ΔKem = + 1.

  Spray control is performed based on the control signals output by the three control circuits 30A, 30B, and 30C.

The normal-time spray increase / decrease setting means 110 obtains the spray increase / decrease set value ΔKnm during normal operation from the spray increase / decrease set value ΔKls at the time of constant operation and the spray increase / decrease set value ΔKlf at the time of load change. Since the spray increase / decrease set value ΔKls operates during constant operation and the spray increase / decrease set value ΔKlf operates when the load changes, a signal is exclusively output. However, considering the possibility that the spray increase / decrease set value ΔKls and the spray increase / decrease set value ΔKlf operate simultaneously, the spray increase / decrease set value ΔKnm is obtained from the table shown in FIG.
FIG. 6 is an explanatory diagram of a setting example of the normal time spray increase / decrease setting means 110 of the control device 30 used in the high humidity gas turbine power plant according to the first embodiment of the present invention.

  In FIG. 6, the horizontal axis indicates the spray increase / decrease set value ΔKls, and the vertical axis indicates the spray increase / decrease set value ΔKlf. Then, the normal spray increase / decrease set value ΔKnm is set by a combination of these set values. For example, when the spray increase / decrease set value ΔKls is −1 and the spray increase / decrease set value ΔKlf is −1, the normal spray increase / decrease set value ΔKnm is set to −1. When the spray increase / decrease set value ΔKls is +1 and the spray increase / decrease set value ΔKlf is +1, the normal spray increase / decrease set value ΔKnm is set to +1.

Further, the spray increase / decrease setting means 111 in FIG. 2 includes the spray increase / decrease set value ΔKnm output by the normal spray increase / decrease setting means 110 during normal operation and the exhaust gas temperature limit spray when the exhaust temperature limit spray increase / decrease setting means 109 outputs. The increase / decrease setting value ΔKD of the spray is obtained from the increase / decrease setting value ΔKem. The spray increase / decrease set value ΔKem at the time of exhaust gas temperature limit becomes +1 when the operation limit condition of the gas turbine is deviated. Therefore, the spray increase / decrease setting means 111 obtains the spray increase / decrease set value ΔKD from the table shown in FIG. .
FIG. 7 is an explanatory diagram of a setting example of the spray increase / decrease setting unit 111 of the control device 30 used in the high humidity gas turbine power plant according to the first embodiment of the present invention.

  In FIG. 7, the horizontal axis represents the spray increase / decrease set value ΔKem, and the vertical axis represents the spray increase / decrease set value ΔKnm. The spray increase / decrease set value ΔKD is set by a combination of these set values. For example, when the spray increase / decrease set value ΔKem is 0 and the spray increase / decrease set value ΔKnm is −1, the spray increase / decrease set value ΔKD is set to −1. When the spray increase / decrease set value ΔKem is +1 and the spray increase / decrease set value ΔKnm is +1, the spray increase / decrease set value ΔKD is set to +1.

  Further, in FIG. 2, the spray number command setting means 112 calculates the spray number command value KspD from the current spray number and the spray increase / decrease setting value ΔKD. Further, the spray control means 113 opens and closes the corresponding on / off electric valve 9 according to the spray number command value KspD, and drives the number of sprays equal to the spray number command value KspD.

Next, the control result of the high humidity gas turbine plant will be described with reference to FIGS.
8 to 10 are trend graphs showing the control results of the high-humidity gas turbine plant. FIG. 8 is an example of plant load operation characteristics when the present invention is not applied. FIG. 9 is another example of plant load operation characteristics in the city where the present invention is applied. FIG. 10 shows plant load operation characteristics when the control apparatus according to the present embodiment is applied to high-humidity gas turbine control.

  Moreover, in each figure of FIGS. 8-10, the horizontal axis has shown time. The vertical axis of each figure (A) shows power generation amount command value MWD. Each figure (B) has shown spray number command value KspD. Each figure (C) has shown turbine exhaust temperature Tx. Each figure (D) shows the generator output MW.

  FIG. 8 is an example of plant load operation characteristics when the present invention is not applied. Here, as shown in FIG. 8B, the spray command value KspD is increased or decreased simultaneously with the fluctuation of the power generation command value MWD shown in FIG. As shown in FIG. 8C, the turbine exhaust temperature Tx fluctuates due to fluctuations in the power generation amount command value MWD and the spray number command value KspD, and the generator output MW changes as shown in FIG. 8D. Therefore, the fluctuation of these process values is also shown.

  Here, based on the overall system plan, it is assumed that the number of sprays before the load increase is k and the number of sprays after the load increase is k + 1. Therefore, in plant control, it is necessary to increase the number of sprays from k to k + 1 according to some index during load change. Therefore, the spray command value KspD was increased from k to k + 1 simultaneously with the increase in power generation amount command value MWD (load increase). As a result of the change in the number of sprays, as shown in FIG. 8 (B), the turbine exhaust temperature Tx once decreases and then increases as the fuel flow rate increases. A line Txh in the figure shows a transition characteristic of the turbine exhaust temperature Tx when k + 1 sprays are injected at the time of load change. The turbine exhaust temperature after the load increase coincides with the point th, which coincides with the planned value of the turbine exhaust temperature after the load change.

  When the turbine exhaust temperature is lowered due to spray injection at the time of increasing the load, it is considered that the combustor temperature (turbine inlet temperature) is similarly lowered. When the turbine inlet temperature decreases, the turbine driving force decreases, so that the power generation amount MW decreases transiently as shown in FIG. 8D, and the load followability deteriorates.

  Further, when this operation method is applied at the time of load reduction, the operation is such that the number of sprays is reduced from k + 1 to k at the start of load change. When the spray flow rate is reduced at the start of load change, the turbine exhaust temperature Tx rises to tD (° C.) at the maximum, as shown in FIG. 8B. A line TxD in the figure shows a transition characteristic of the turbine exhaust temperature Tx when k sprays are injected at the time of load change. In addition to an increase in the amount of power generated due to an increase in combustion temperature, it causes melting of the combustor and turbine blades. Therefore, as a result of restricting the opening degree of the fuel flow control valve to avoid damage to the combustor and the turbine blade, the load followability is transiently lowered as shown in FIG. 8 (D).

  Next, FIG. 9 is another example of the plant load operation characteristics when the present invention is not applied. In this example, spray spraying during a load change where the process amount becomes unstable is avoided, and the spray number command value KspD is controlled to increase or decrease after the end of the load fluctuation. In such a control method, when the load is increased, as shown in FIG. 9B, the turbine exhaust temperature Tx rises to the maximum at tD '(° C) and then drops to the planned value by spraying. Simultaneously with the decrease in Tx, as shown in FIG. 9D, the power generation amount MW also decreases. In the figure, the amount of power generation temporarily decreased at the end of the load increase.

  When this operation method is applied at the time of load reduction, spray spraying is continued until the end of load change, so that the turbine exhaust temperature Tx varies along a line Txh as shown in FIG. 9B. Further, the exhaust temperature is temporarily increased from the temperature th ′ as shown in FIG. 9B by reducing the number of sprays from k + 1 to k after the load change. Therefore, as shown in FIG. 9D, when the load is reduced, the power generation amount temporarily increases due to the increase in the turbine exhaust temperature.

  Next, referring to FIG. 10, the plant load operation characteristics when the control device 30 according to the present embodiment is applied to the high-humidity gas turbine control will be described. In this embodiment, the gas turbine exhaust temperature Tx is monitored, and when the difference between the gas turbine exhaust temperature and the target value exceeds the set temperature difference, the number of sprays is changed. In this control method, as shown in FIG. 10B, the turbine exhaust temperature Tx at the time of increasing the load is a value along the dotted line TxD, and the turbine exhaust temperature at the end of the load change is a value along the dotted line Txh. When the number of sprays is switched from k to k + 1, as shown in FIG. 10C, the gas temperature temporarily decreases. However, the decrease in the turbine exhaust temperature due to the increase in the number of sprays is the temperature increase before spraying. Therefore, the temperature change rate becomes a small value as compared with the control methods shown in FIGS. As a result of suppressing the turbine exhaust temperature fluctuation, as shown in FIG. 10 (D), the fluctuation of the generator output is also minimized.

  Similarly, in the case of load reduction, when the difference between the turbine exhaust temperature Tx and the target value exceeds the set temperature difference, the number of sprays is changed from k + 1 to k. Since the temperature increase due to the decrease in the number of sprays cancels out the temperature decrease when the turbine load decreases, the temperature change rate can be reduced as compared with the control methods shown in FIGS. In addition, as shown in FIG. 10D, fluctuations in the amount of power generation can be minimized.

  As described above, according to the present embodiment, since the spray spray timing is determined so that the temperature fluctuation at the time of increasing or decreasing the load and the temperature fluctuation due to the spray spray are offset, the thermal stress on the turbine blade is minimized. As a result, it is possible to perform a load operation without difficulty. At the same time, since fluctuations in turbine exhaust temperature are minimized, stable load operation is possible with minimum disturbance for each of power generation amount, generator frequency, and turbine rotation speed. Therefore, various process amounts of the plant such as the turbine exhaust temperature Tx and the power generation amount MW can be stably controlled even during the load change operation.

  Further, since the spray control is an on / off control by the electric valve, it is possible to supply a cheaper plant while suppressing the cost of the spray equipment. Moreover, since various calibration operations such as flow rate adjustment in the spray are not required, the trial run period can be shortened.

Next, the configuration and operation of the control device for the gas turbine equipment according to the second embodiment of the present invention will be described with reference to FIGS. 11 and 12. The system diagram of the high-humidity gas turbine power plant according to this embodiment is the same as that shown in FIG.
FIG. 11 is a functional block diagram showing a detailed configuration of a control device 30 ′ used in the high humidity gas turbine power plant according to the second embodiment of the present invention. The same reference numerals as those in FIG. 2 denote the same parts.

  FIG. 12 shows plant load operation characteristics when the control device according to the present embodiment is applied to high-humidity gas turbine control. In FIG. 12, the horizontal axis indicates time. The vertical axis in FIG. 12A indicates the power generation amount command value MWD. FIG. 12B shows the spray number command value KspD. FIG. 12C shows the turbine exhaust temperature Tx. FIG. 12D shows the generator output MW. . FIG. 12E shows the spray control command value KspD2.

  In the embodiment shown in FIG. 2, all i sprays are controlled by on / off motorized valves, whereas in the present embodiment shown in FIG. 11, at least one of these sprays is a proportional control valve 19. The other i-1 are used as the on / off motor-operated valve 9.

  The configurations of the first control circuit 30A and the third control circuit 30C are the same as those shown in FIG.

  The second control circuit 30B ′ calculates the number of operation of the motor-operated valves at the time of plant load change operation. The turbine exhaust temperature setting means 101, the subtractor 105, the PID controller 121, and the spray increase / decrease setting means. 122.

  The turbine exhaust temperature setting means 101 obtains the exhaust temperature target value TxD from the power generation amount command value MWD as described in FIG. The subtractor 105 subtracts the turbine exhaust temperature Tx and the exhaust temperature target value TxD obtained by the turbine exhaust temperature setting means 101 to obtain an exhaust temperature deviation ΔTx.

  The turbine exhaust temperature deviation ΔTx is input to the PID controller 121. The PID controller 121 calculates a spray control command value KspD2 for setting the turbine exhaust temperature deviation ΔTx2 to zero. The opening degree of the proportional control valve 19 is controlled based on the spray control command value KspD2. The spray increase / decrease setting means 122 inputs the spray control command KspD2, and when this signal becomes the upper limit or the lower limit of the spray opening, the spray increase / decrease set value ΔKlf is set to +1 or −1. The spray increase / decrease setting value ΔKlf is input to the normal spray increase / decrease setting means 110.

  Here, the plant control result by this embodiment is demonstrated using FIG. In the example shown in the figure, as shown in FIG. 12E, when the spray opening KspD2 of the proportional control valve 19 controlled by the PID controller 121 is equal to or greater than α, the spray increase / decrease setting means 122 The increase / decrease set value ΔKlf is set to +1, and the spray increase / decrease set value ΔKlf is set to −1 when it is equal to or less than β. That is, in the embodiment shown in FIG. 2, the deviation of the turbine exhaust temperature Tx from the target value is used as a trigger for spray injection, whereas in this embodiment, the opening of the spray control valve is used as a trigger for spray injection.

  As shown in FIG. 12E, the initial fluctuation of the temperature at the time of load change is controlled by the spray control command value KspD2. When the value of the spray control command value KspD2 is greater than or equal to α as shown in FIG. 12E, the number of sprays KspD is increased as shown in FIG. The spray control command KspD2 compensates for the decrease in the turbine exhaust temperature Tx accompanying the increase in the number of sprays.

  In the above description, the valve opening of the spray 19 at a constant load is set to an intermediate opening between α and β, and the spray 19 is configured to flow a constant flow rate at a constant load. The valve opening degree of 19 may be operated to be 0.

  As described above, according to this embodiment, various process amounts of the plant such as the turbine exhaust temperature Tx and the power generation amount MW can be stably controlled even during the load change operation.

  Further, in this method, since the turbine exhaust temperature Tx can be continuously controlled using the proportional control valve 19, the fluctuation range of the turbine exhaust temperature Tx and the generator output MW at the time of load change is the first embodiment. It is possible to make it smaller.

Next, the configuration and operation of the control device for the gas turbine equipment according to the third embodiment of the present invention will be described with reference to FIGS. The system diagram of the high-humidity gas turbine power plant according to this embodiment is the same as that shown in FIG.
FIG. 13 is a functional block diagram showing a detailed configuration of the control device 30 ″ used in the high-humidity gas turbine power plant according to the third embodiment of the present invention. The same reference numerals as those in FIG. 2 denote the same parts. Yes.

  In this embodiment, in addition to the control circuits 30A, 30B, and 30C shown in FIG. 2 for spray control, a fourth control circuit 30D for fuel adjustment valve control is provided, and both are controlled in coordination. I have to. The configurations and operations of the control circuits 30A, 30B, and 30C are the same as those described in FIG.

  The fourth control circuit 30D limits load control by the fuel adjustment valve during spray number control in order to reduce the influence of load disturbance on the fuel adjustment valve during spray number control. Further, when the gas turbine exhaust temperature exceeds the alarm value, the fuel regulating valve is controlled and at the same time the number of sprays is increased to protect the gas turbine combustor.

  The fourth control circuit 30D includes load deviation correcting means 300, frequency correcting means 201, turbine rotation speed correcting means 202, low value selecting means 203, and exhaust temperature control means 204.

  The load deviation correcting means 300 is a normal time spray setting that is an output of the load deviation ΔMW that is the difference between the power generation amount (MW) obtained by the subtractor 103 and the power generation amount command value (MWD) and the normal time spray increase / decrease setting means 110. The increase / decrease value ΔKnm is input, and the load deviation correction value ΔMWa is output. The load deviation correction value ΔMWa sets the load deviation detection sensitivity low when the number of sprays changes (ΔKnm ≠ 0).

Here, a setting example of the load deviation correcting means 300 will be described with reference to FIG.
FIG. 14 is an explanatory diagram of a setting example of the load deviation correcting means 300 of the control device 30 ″ used in the high humidity gas turbine power plant according to the third embodiment of the present invention. The horizontal axis of FIG. 14 is the load deviation ΔMW. (MW) and the vertical axis represents the load deviation correction value ΔMWa (MW).

  When the number of sprays does not change, as shown by the dotted line B, the load deviation correction value ΔMWa (MW) is 0 when the load deviation ΔMW (MW) is in the range of 0 ± b (MW). Increase or decrease in proportion to the deviation ΔMW. As a result, the fuel adjustment valve 6 is controlled so that the load deviation ΔMW is within ± b (MW). On the other hand, when the number of sprays changes, as shown by the solid line A, the load deviation correction value ΔMWa (MW) is 0 when the load deviation ΔMW (MW) is in the range of 0 ± a (MW), and otherwise, the load deviation ΔMW Increases or decreases in proportion to Thus, when the number of sprays varies, the dead zone is expanded to ± a (MW), and the fuel adjustment valve 6 is controlled so that the load deviation ΔMW is within ± a (MW).

  In a high-humidity gas turbine, the power generation amount may fluctuate over a long period due to spray spraying. That is, temperature fluctuations due to spraying cause load fluctuations, and fuel flow fluctuations accompanying the load fluctuations cause further load fluctuations. Moreover, since the turbine exhaust gas temperature fluctuates with the load fluctuation, the load fluctuation also occurs when the air temperature at the outlet of the regenerative heat exchanger fluctuates.

  The load deviation correction means 300 can set the entire plant in a steady state earlier by setting the sensitivity of the fuel flow rate to be low with respect to the power generation amount deviation due to the variation in the number of sprays.

Here, a setting example of the dead band correction value D (MW) in the load deviation correction means 300 will be described with reference to FIG.
FIG. 15 is an explanatory diagram of a setting example of the dead band correction value D in the load deviation correction means 300 of the control device 30 ″ used in the high humidity gas turbine power plant according to the third embodiment of the present invention. The horizontal axis represents the absolute value of the normal spray increase / decrease setting value ΔKnm, and the vertical axis represents the dead band correction value D.

  In this example, when the normal time spray increase / decrease setting value ΔKnm is 0, the dead band correction value D is a (MW), and when it is not 0, the band correction value D is b (MW). Since the normal spray increase / decrease setting value ΔKnm takes a value of -1, 0, or +1, when switching between a and b, the load deviation correction means 300 sets the dead band correction value D as shown in FIG. As shown by a dotted line, the value is continuously switched from a to b or from b to a. Then, the load deviation correction means 300 obtains the load deviation correction value ΔMWa for the load deviation ΔMW by giving the dead band as shown in FIG. 14 according to the dead band correction value D.

  In FIG. 14, the frequency correction unit 201 calculates a frequency correction value from the generator frequency and the frequency target value, and obtains the load deviation correction value ΔMWb by superimposing the frequency correction value on the load deviation correction value ΔMWa. The turbine rotation speed correction means 202 calculates a rotation speed correction value from the generator rotation speed and the rotation speed target value, superimposes the rotation speed correction value on the load deviation correction value ΔMWb, and sets the normal fuel adjustment valve opening Cnm. Ask. Speed control such as generator frequency correction and turbine rotation speed correction is based on “maintaining voltage and frequency” defined in the Electricity Business Law, and is also provided in conventional gas turbine power plants. In FIG. 13, the sensitivity of the fuel flow rate with respect to the power generation amount deviation is set low in consideration of the power generation amount variation due to the variation in the number of sprays.

  Regarding the power generation amount, the same amount control within 30 minutes is imposed on the power generation amount command from the central power supply command center (medium pay), but the generator frequency is ± 1 Hz with respect to the system frequency. In the event of a difference, the generator is shut off from the grid as it impairs the stability of the grid. Since the control of the frequency and the rotational speed is stricter than the power generation amount control, when the sensitivity correction is applied to the control of the frequency and the rotational speed, it is necessary to add a correction in consideration of the load operation performance of the plant.

  On the other hand, the subtractor 106 obtains an exhaust temperature deviation ΔTxLim from the turbine exhaust temperature Tx and the turbine exhaust temperature limit value TxLim. The exhaust gas temperature control means 204 obtains the fuel adjustment valve opening degree Cem at the time of exhaust gas temperature restriction from the exhaust gas temperature deviation ΔTxLim.

  The low value selection means 203 inputs the normal fuel adjustment valve opening Cnm and the exhaust temperature limit fuel adjustment valve opening Cem, and the low value selection selects the normal fuel adjustment valve opening Cnm and the exhaust temperature limit fuel adjustment valve. The lower value of the opening degree Cem is output to the fuel flow adjustment valve 6 as the fuel adjustment valve opening degree Cgov.

  On the other hand, when the exhaust temperature deviation ΔTxLim is 0 or a positive number, the turbine exhaust temperature limit spray increase / decrease setting means 109 increases the number of sprays by setting the exhaust temperature limit spray increase / decrease setting ΔKem = + 1.

  The adjustment valve opening Cgov is highly responsive to the exhaust temperature, and the increase in the number of sprays is highly sensitive to the temperature drop. Therefore, when the exhaust temperature is limited, the number of sprays increases after the adjustment valve opening operation, and the exhaust temperature can be reliably controlled within the limit value.

  As described above, according to this embodiment, various process amounts of the plant such as the turbine exhaust temperature Tx and the power generation amount MW can be stably controlled even during the load change operation.

Further, when the exhaust temperature of the turbine rises, the exhaust temperature is limited by using both the fuel and spray operation amounts, so that more reliable exhaust temperature control is possible. In particular, since the spray limit is used together with the exhaust temperature, which is conventionally limited only by the fuel flow rate, the plant can be operated without significantly reducing the reference value of the fuel flow rate. Further, since the rated operation can be restored only by adjusting the spray flow rate, the rated operation can be easily started.

1 is a system diagram of a high humidity gas turbine power plant according to a first embodiment of the present invention. It is a functional block diagram which shows the detailed structure of the control apparatus 30 used for the high humidity gas turbine power plant by the 1st Embodiment of this invention. It is explanatory drawing of the example of a setting of the spray number setting means 100 of the control apparatus 30 used for the high humidity gas turbine power plant by the 1st Embodiment of this invention. It is explanatory drawing of the example of a setting of the turbine exhaust temperature setting means 101 of the control apparatus 30 used for the high humidity gas turbine power plant by the 1st Embodiment of this invention. It is explanatory drawing of the example of a setting of the turbine exhaust temperature limit value means 200 of the control apparatus 30 used for the high-humidity gas turbine power plant by the 1st Embodiment of this invention. It is explanatory drawing of the example of a setting of the normal time spray increase / decrease setting means 110 of the control apparatus 30 used for the high humidity gas turbine power plant by the 1st Embodiment of this invention. It is explanatory drawing of the example of a setting of the spray increase / decrease setting means 111 of the control apparatus 30 used for the high humidity gas turbine power plant by the 1st Embodiment of this invention. It is a trend graph which shows the control result of a high humidity gas turbine plant. It is a trend graph which shows the control result of a high humidity gas turbine plant. It is a trend graph which shows the control result of a high humidity gas turbine plant. It is a functional block diagram which shows the detailed structure of control apparatus 30 'used for the high humidity gas turbine power plant by the 2nd Embodiment of this invention. The plant load operation characteristic at the time of applying the control device by this embodiment to high-humidity gas turbine control is shown. It is a functional block diagram which shows the detailed structure of control apparatus 30 '' used for the high-humidity gas turbine power plant by the 3rd Embodiment of this invention. It is explanatory drawing of the example of a setting of the load deviation correction means 300 of the control apparatus 30 '' used for the high humidity gas turbine power plant by the 3rd Embodiment of this invention. It is explanatory drawing of the example of a setting of the dead zone correction value D in the load deviation correction means 300 of the control apparatus 30 '' used for the high-humidity gas turbine power plant by the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Gas turbine 2 ... Compressor 3 ... Combustor 4 ... Generator 5 ... Fuel pump 6 ... Fuel flow control valve 8 ... Spray 9 ... Electric valve 19 ... Spray control valve 30 ... Control device 100 ... Spray number setting means 101 ... Turbine exhaust temperature setting means 103, 104, 105, 106 ... Subtractor 107 ... Spray increase / decrease setting means during constant operation 108 ... Spray increase / decrease setting means during load change operation 109 ... Spray increase / decrease setting means during exhaust temperature limit 110 ... Spray increase / decrease during normal operation Setting means 111 ... Spray increase / decrease setting means 112 ... Spray number command setting means 113 ... Spray control means 121 ... PID controller 122 ... Spray increase / decrease setting means 200 ... Turbine exhaust temperature limit value means 201 ... Frequency correction means 202 ... Turbine rotation speed correction Means 203 ... Low value selection means 204 ... Exhaust temperature control means 300 ... Load deviation correction Steps

Claims (6)

A compressor that compresses air; a combustor that combusts air and fuel compressed by the compressor; a turbine that is driven by combustion gas generated by the combustor; and an intake or compressor of the compressor A control device for gas turbine equipment having a water adding device for supplying water to compressed air compressed in
When the difference between the effective output of the generator connected to the turbine and the output target value of the generator exceeds a predetermined value, a control means is provided for changing the amount of water supplied to the intake air or compressed air. A control device for gas turbine equipment. A compressor that compresses air; a combustor that combusts air and fuel compressed by the compressor; a turbine that is driven by combustion gas generated by the combustor; and an intake or compressor of the compressor A control device for gas turbine equipment having a water adding device for supplying water to compressed air compressed in
The control means changes a water supply amount to the intake air or compressed air when a difference between an exhaust temperature at the turbine outlet and a target value of the exhaust temperature exceeds a predetermined value. Equipment control device. A compressor that compresses air; a combustor that combusts air and fuel compressed by the compressor; a turbine that is driven by combustion gas generated by the combustor; and an intake or compressor of the compressor A control device for gas turbine equipment having a water adding device for supplying water to compressed air compressed in
When the difference between the exhaust temperature of the turbine outlet and the maximum use temperature (alarm value) of the exhaust temperature exceeds a predetermined value, the control means changes the amount of water supplied to the intake air or compressed air. A control device for gas turbine equipment. In the control apparatus of the gas turbine equipment in any one of Claims 1-3,
The water adding device has a plurality of on-off motorized valves and one proportional control valve,
The control device of the gas turbine equipment, wherein the control means controls opening / closing of the on / off control valve according to an opening degree of the proportional control valve. In the control apparatus of the gas turbine equipment in any one of Claims 1-3,
The control device for gas turbine equipment, wherein the control means controls the amount of fuel supplied to the combustor based on a difference between an effective output of the generator and an output target value of the generator. In the control apparatus of the gas turbine equipment in any one of Claims 1-3,
The control apparatus for gas turbine equipment, wherein the water adding device is realized by a combination of a plurality of water injection nozzles.

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