JPH06264761A - Controller for gas turbine - Google Patents

Abstract

PURPOSE:To provide a controller for a gas turbine which can compensate detection lag of exhaust gas temperature and quickly grasp fluctuation of exhaust gas temperature. CONSTITUTION:Blade pass temperature 21 is measured in the vicinity of the port of a gas turbine 3, measured blade pass temperature 21 is given to an exhaust to an exhaust gas temperature lag compensation means 22, normally existing deviation is removed by in-pass lag so as to pass only temperature fluctuation due to fluctuation of generated amount of energy, and a compensation signal is determined by specific gain of a coefficient multiplier 24 so as to compensate deviation lag of exhaust gas temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas turbine control device.

[0002]

2. Description of the Related Art Conventionally, FIG.
There is one configured as shown in.

In the figure, reference numeral 9 is a gas turbine plant. This gas turbine plant 9 compresses air by a compressor 1, guides it to a combustor 2 and burns it to generate high temperature and high pressure gas. Then, the power generated when the high-temperature, high-pressure gas is expanded by the turbine 3 rotates the generator 4 to obtain electric power.

On the other hand, 18 is a gas turbine control device,
The control device 18 of this gas turbine is connected to the fuel control system 12 and I
It comprises a GU (inlet guide vane) control system 15. Then, the fuel control system 12 sets the power generation amount set value 10 to match the power generation amount 5 of the gas turbine plant 9 with P
The I controller 11 is used to output the governor opening command value 16.

The governor 7 of the gas turbine plant opens and closes according to the governor opening command value 16 to adjust the fuel flow rate. For example, when the power generation amount 5 is larger than the power generation amount set value 10, the governor opening command value 16 is output from the fuel control system 12 so as to close the governor 7, and the fuel flow rate is reduced to reduce the power generation amount 5. In this way, the power generation amount 5 is controlled by the fuel control system 12. Although the main control of the gas turbine is related to the above-mentioned power generation amount 5, the control by the exhaust gas temperature 6 is also performed in addition to the power generation amount 5.

The control by the exhaust gas temperature 6 is mainly performed to keep the temperature of the turbine blade at a predetermined value and reduce the thermal load on the blade, and is performed by the IGV control system 15.

Since the exhaust gas temperature 6 at which the thermal load on the turbine blade is minimized differs depending on the combustor pressure 19, the exhaust gas temperature set value 14 is set in the IGV control system 15 by using the function generator 13. It is defined as a function of pressure 19.

The PI controller 111 has an exhaust gas temperature set value of 1
IGV opening command signal 1 so that exhaust gas temperature 6 matches 4
7 is output to change the opening of the IGV 8 to adjust the air flow rate.

Further, when the power generation amount changes suddenly, the IGV 8 is quickly moved by the IGV opening command value 17 to suppress the fluctuation of the exhaust gas temperature 6. In this case, the preceding signal 20 set as a function of the power generation amount 5 is added to the IGV opening command value 17. The preceding signal 20 here is determined by inputting the power generation amount 5 to the function generator 131.

When the exhaust gas temperature 6 rises greatly in this way, the power generation amount 4 must be suppressed in order to protect the turbine blades, but in order to maintain the power generation amount 5 of the gas turbine at a high value. It is important to improve the control performance of the exhaust gas temperature 6 and keep the exhaust gas temperature 6 at a predetermined value.

[0011]

By the way, in order to improve the control performance of the gas turbine, the delay time in each detector must be minimized. This is because if the detection delay is large, it is not possible to catch minute fluctuations in the control amount.

However, the detector used for measuring the exhaust gas temperature 6 of the gas turbine plant 9 has a large delay time, and it is difficult to improve the control performance of the exhaust gas temperature 6 without changing the detector.

Therefore, a method of replacing the detector with a detector having a short delay time may be considered, but in view of durability of the detector, the current detector has to be used. Therefore, it is necessary for the control system to compensate the exhaust gas temperature measurement delay time by some means in order to improve the control performance of the exhaust gas temperature 6.

The present invention has been made in view of the above circumstances and is capable of compensating for the delay in detecting the exhaust gas temperature.
An object of the present invention is to provide a gas turbine control device that can quickly detect fluctuations in exhaust gas temperature.

[0015]

SUMMARY OF THE INVENTION The present invention is directed to a means for measuring the blade path temperature near the outlet of a gas turbine, and a temperature associated with fluctuations in the amount of power generated by removing the steady deviation of the blade path temperature measured by this means. The exhaust gas temperature delay compensating means having a coefficient unit for setting a predetermined gain for determining a compensation signal is provided, and the exhaust gas temperature delay compensating means compensates for the detection delay of the exhaust gas temperature. Has been done.

[0016]

As a result, according to the present invention, the blade path temperature measured in the vicinity of the outlet of the gas turbine is applied to the exhaust gas temperature delay compensating means, where the steady deviation is removed by the in-path lag to change the temperature with the fluctuation of the power generation amount. Only the gas is allowed to pass through and the compensation signal is determined by a predetermined gain of the coefficient unit to compensate for the exhaust gas temperature detection delay. As a result, it becomes possible to quickly detect fluctuations in the exhaust gas temperature and improve the control performance of the exhaust gas temperature.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of the same embodiment. In FIG. 1, the same parts as those in FIG. 3 are designated by the same reference numerals. The gas turbine plant 9 measures the blade path temperature 21 near the outlet of the turbine 3. In this case, since the blade path temperature 21 is on the upstream side of the exhaust gas temperature 6, the detection delay time is about half that of the exhaust gas temperature 6.
The following is excellent in responsiveness.

However, in the vicinity of the outlet of the turbine 3 where the blade path temperature 21 is measured, the exhaust gas is not uniformly mixed and varies depending on the place. Therefore, the blade path temperature 21 has a steady deviation from the exhaust gas temperature 6 due to the influence of this variation, and due to this deviation, the blade path temperature 21 is excellent in responsiveness. Without being used in the IGU control system 15. Therefore, the blade path temperature 21 in the gas turbine plant 9 is given to the exhaust gas temperature delay compensating means 22. The exhaust gas temperature delay compensating means 22 utilizes the rapid response characteristic of the blade path temperature 21 to control the exhaust gas temperature 6
Is to compensate for the time delay of detection. By the way, a problem in using the blade path temperature 21 for control is the steady-state deviation caused by the above-mentioned temperature variation at the outlet of the turbine 3. The in-pass lag 23 is effective for removing this steady-state deviation.

FIG. 2 shows the frequency characteristics of the impulse lag 23, showing that low frequency signals having a frequency of 1 / τ or less are blocked and high frequency signals having a frequency of 1 / τ or more are passed through without being attenuated. There is.

Since the steady-state deviation which is a problem in the blade path temperature 21 is a low frequency signal, it is removed by the impulse lag 23 shown in FIG. Will pass through. Here, the time constant of the impulse lag 23 may be set to the same degree as the detection delay of the exhaust gas temperature 6. Further, the coefficient unit 24 of the exhaust gas temperature delay compensating means 22 is a gain for determining the magnitude of the compensation signal 25 for compensating the detection delay of the exhaust gas temperature 6. Here, the magnitude of the gain of the coefficient unit 24 is determined as follows.

The time constant of the impulse lag 23 is set according to the detection delay time of the exhaust gas temperature 6, and its value is τ seconds, while the detection delay of the blade path temperature 21 is τ.
_{When B} , the relationship of τ _B <τ is generally established.

As an example, the delay time of the exhaust gas temperature 6 is τ
The method of selecting the gain to decrease from τ _B to τ _B is shown. When the transfer function of the detector of the blade path temperature 21 is G _BP , G _BP is given by the following equation. G _BP = 1/1 + τ _B s (1) where s is a Laplace operator. On the other hand, the transfer function G _EX of the detector for the exhaust gas temperature 6 is expressed by the following equation. G _EX = 1/1 + τ _S (2)

Accordingly, from the equations (1) and (2), in order to set the time constant of the transfer function of the compensated signal 26 in which the compensation signal 25 is added and the detection delay is compensated to τ _B , the following equation is established: It will be good. 1 / (1 + τ _B s) = kτ _S / (1 + τ _S ) 1 / (1 + τ _B s) + 1 / (1 + τ _S ) ... (3) When the above equation is rearranged, the gain K of the coefficient unit 24 is given by the following equation. Is obtained. . k = 1-τ _B / τ

By setting the gain K of the exhaust gas temperature delay compensating means 22 in this manner, the exhaust gas temperature 6 having a long detection delay time can be compensated by using the blade path temperature 21.

Therefore, in this way, the exhaust gas temperature delay compensating means is used to compensate the exhaust gas temperature detection delay by using the blade path temperature, so that the fluctuation of the exhaust gas temperature can be swiftly grasped. The control performance can be improved and an efficient gas turbine control device can be realized. The present invention is not limited to the above-mentioned embodiments, and can be implemented by appropriately modifying it without changing the gist.

[0026]

According to the present invention, the blade path temperature measured near the outlet of the gas turbine is given to the exhaust gas temperature delay compensating means, and the steady deviation is removed by the in-pass lag here, and the temperature accompanying the fluctuation of the power generation amount is removed. Since only the fluctuation is passed and the compensation signal is determined by the predetermined gain of the coefficient unit, the exhaust gas temperature detection delay is compensated.
It becomes possible to quickly detect changes in exhaust gas temperature,
The control performance of the exhaust gas temperature can be improved, and an efficient gas turbine control device can be realized.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing frequency characteristics of impulse lag according to an embodiment.

FIG. 3 is a diagram showing an example of a conventional gas turbine control device.

[Explanation of symbols]

1 ... Compressor, 2 ... Combustor, 3 ... Gas turbine, 4 ... Generator, 5 ... Calorific value, 6 ... Exhaust gas temperature, 7 ... Governor, 8 ... IGV, 9 ... Gas turbine plant, 12 ...
Fuel control system, 13, 131 ... Function generator, 111 ... PI
Controller, 21 ... Blade path temperature, 22 ... Exhaust gas temperature delay compensating means, 23 ... In-pass lag, 24 ... Coefficient unit.

Claims (1)

[Claims] 1. A means for measuring a blade path temperature in the vicinity of an outlet of a gas turbine, and a means for removing a steady deviation of the blade path temperature measured by the means and passing only a temperature fluctuation associated with a fluctuation in power generation amount, A gas turbine, comprising: an exhaust gas temperature delay compensating means having a coefficient unit for setting a predetermined gain for determining a compensation signal, wherein the exhaust gas temperature delay compensating means compensates for the detection delay of the exhaust gas temperature. Control device.