JPS61210233A - Gas turbine temperature control device - Google Patents

Abstract

PURPOSE:To prevent production of high frequency heat impact exerted on a moving vane, by a method wherein, in a device in which fuel for plural gas turbine combustors is regulated by a fuel regulating valve, a fuel regulator valve, located to each combustor, is regulated by means of unevenness in an exhaust gas temperature. CONSTITUTION:In a gas turbine combustor part, fuel 7 is fed to each combustor 3 through a fuel regulating valve 4 mounted to each combustor 3, and is burnt under the feed of compressed air 34 from a compressor 33. After combustion gas 28 is caused to pass, in order, a first stage stationary vane 29, a first stage moving vane 30, a second stage stationary vane 31 and a secondary stage stationary moving vane 32 to rotate and drive the moving vane 30 and 32, the combustion gas is fed out as exhaust gas to an exhaust part 8. In which case, exhaust gas temperature detectors 9 in the same quantity as that of the combustor 3 are situated to the exhaust part 8 and in the same peripheral position as that of the combustor 3, and exhaust gas temperature distribution is measured by the temperature detector 9. When unevenness in the exhaust gas temperature exceeds the thermal stress allowable range of a high temperature part, a fuel regulating valve 4 related to the combustor 3 by which the unevenness is caused is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a gas turbine control device, and particularly to a temperature control device suitable for improving the life of high-temperature components of a gas turbine combustor section.

[Background of the invention]

FIG. 2 shows the structure of a conventional gas turbine combustion section having a fuel control function and a combustion gas temperature control function. 7 liters of fuel,
The fuel is evenly distributed through one fuel control valve 5 to a plurality of combustors 3 arranged concentrically. combustion gas 28
are the fourth stage stationary blade 29, the second stage rotor blade 32, and the second stage rotor blade 32.
, passes through the second stage rotor blade 32 and exits to the exhaust section 8.

Conventionally, the turbine combustor 3, rotor blades 30, 32 and 29
, 31, etc., the exhaust gas temperature is detected and, using this average value, the fuel control valve 5, which collectively adjusts the amount of fuel to all the combustors 3, adjusts the temperature. is in control.

In other words, (1) the temperature distribution inside the combustor is unbalanced, so it is difficult to measure the average combustion temperature;
Due to the high combustion temperature, it is difficult to measure directly.
Exhaust gas temperature is detected by a plurality of temperature detectors 9 attached on the concentric circumference of the gas turbine exhaust section 8. The average value is fed back to the temperature control device and compared with a pre-given exhaust gas temperature set value, and based on the deviation, the amount of fuel to all combustors 3 is adjusted at once to the fuel control valve 5.
Control with.

In this method, fuel is supplied to multiple combustors 3 using one fuel control valve 5, so the amount of fuel to each combustor may differ slightly. The mixture ratio of fuel and fuel (hereinafter referred to as fuel-air ratio) is not necessarily the same in all combustors. the result,
A temperature difference occurs in the combustion gas temperature between each combustor, causing variations in the temperature distribution inside the turbine.

Therefore, since the rotor blades 30 and 32 rotate at high speed in the combustion gas with this temperature difference, the rotor blades 30 and 32 are
The thermal stress applied to 0.32 increases.

Furthermore, due to the temperature difference between the combustors, thermal stress is applied to the casing 25 that covers the combustor, causing deformation, cracking, and even damage.

(9) In the conventional temperature control method, the temperature is controlled based on the average value of the exhaust gas temperature, so if the temperature of a certain combustor rises abnormally, there is a risk that the combustor will be damaged. Methods for making the combustion gas temperature distribution uniform include (1) a method of introducing cooling air into the combustor, and (2) a method of adjusting the fuel flow rate to the combustor.

Method (1) is as described in JP-A-54-38427, in which cooling air is injected into the combustor outlet, the temperature of the combustion gas after combustor 3 is adjusted, and the temperature inside the gas turbine is controlled. By making the temperature distribution uniform, high-frequency thermal shock applied to the dynamic JK30.32 is prevented as much as possible. However, no consideration was given to deformation and damage to the casing 25 due to temperature differences between the combustors and damage due to an abnormal temperature rise in the combustor 3.

[Purpose of the invention]

The purpose of the present invention is to uniformize the combustion gas temperature of each combustor in order to prevent damage due to high-frequency thermal shock applied to the rotor blades, abnormal temperature rise in the combustor, deformation of the casing due to temperature difference between combustors, and damage as much as possible. An object of the present invention is to provide a control device that improves the life of high-temperature parts of a gas turbine.

[Summary of the invention]

In order to achieve the above object, the present invention installs a fuel control valve in each combustor to adjust the amount of fuel to each combustor, detects variations in exhaust gas temperature, and controls the fuel control valve.
The aim is to minimize that variation.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1, 3, and 4.

FIG. 1 shows the structure of a gas turbine combustor section to which the present invention is applied. The fuel 7 is supplied to each combustor 3 via a fuel control valve 4 that adjusts the amount of fuel supplied to each combustor 3, and is mixed and combusted with compressed air 34 compressed by a compressor 33. After passing through the first stage rotor blade 29t, the combustion gas 28 gives energy to the first stage rotor blade 30 and drives the gas turbine.

Furthermore, after passing through the first stage rotor blades 30, energy is applied to the second stage rotor blades 32, and the gas is guided to the exhaust section 8 as exhaust gas. In the exhaust part 8, exhaust gas temperature detectors 91r are installed at the same circumferential position as the combustor 3 and in the same number as the nine combustors. This @temperature detector 9 measures the exhaust gas temperature distribution, and if the variation is greater than the allowable range of thermal stress for high-temperature parts, a means for detecting the combustor causing the variation is used to detect the combustion A fuel control valve 4 adjusts the amount of fuel supplied to the container.

FIG. 3 shows a control system diagram of the present invention. The temperature detector 9 measures the exhaust gas temperature for each combustor 3, and sends each temperature detection signal 1 (l signal amplifier 11 to the temperature control device 1).
Enter into 2. Here, the means to detect the combustor that is the cause of the variation in exhaust gas temperature, that is, calculate the intermediate value of the exhaust gas temperature, and the deviation between the intermediate value and the value of the exhaust gas temperature detector corresponding to each combustor. By taking
- Output. This control signal 13 is transmitted to an automatic manual switch 14.
The fuel control valve 4t is controlled via the fuel control valve 4t.

When the temperature control device is abnormal or when manual control is required, the exhaust gas temperature detection signal 16 amplified by the signal amplifier 11 is taken in and monitored by a combustor monitor device 17 that monitors the state of the combustor. A control block diagram of the temperature control device 12 is shown in FIG. 4, in which it is possible to control the fuel control valve 4 with the manual operating device 15 to achieve a uniform temperature distribution.

The exhaust gas temperature detection signal 16 amplified by the signal amplifier 11 is taken in by the temperature control device 12 . From this signal 16, an intermediate value selector 18 calculates an intermediate exhaust gas temperature signal 19. This signal 19 and the detected exhaust gas temperature signal 16 are transferred to a comparator 2.
If the deviation signal 21 exceeds the allowable range (±α) for the intermediate value 19, it is determined that the combustion gas temperature distribution is not uniform. At this time, the proportional integrator 22 calculates -
Based on the calculated result, that is, the control output signal 13, the fuel amount of the corresponding combustor is controlled by the fuel control valve 4, and the combustion gas temperature is controlled to be the same temperature within the allowable range for each combustor.

To set the value of the allowable range ±α,
When the temperature of the combustor changes, only the amount of fuel in the combustor can be adjusted. In other words, the change in exhaust gas temperature is
This is intended to minimize this influence, since it is affected not only by the temperature of the exhaust gas corresponding to that combustor, but also by the temperature of the exhaust gas corresponding to the adjacent combustor.

〔Effect of the invention〕

According to the present invention, it is possible to minimize the high-frequency thermal shock applied to the rotor blades, and further, by controlling the temperature of the combustion gas from the combustor, which has not been done in the past, it is possible to prevent damage to the combustor due to high temperatures, and to prevent damage to the combustor due to high temperature. This can prevent deformation, cracking, and damage of the casing caused by temperature differences between the two.

As a result, the life of the high-temperature parts of the gas turbine can be improved, and as a result, the time for replacing the high-temperature parts can be extended and operating costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of a gas turbine combustion section to which the present invention is applied;
FIG. 2 is a structural diagram of a conventional gas turbine combustion section, FIG. 3 is a control system diagram, and FIG. 4 is a block diagram of a temperature control device.

Claims (1)

[Claims] 1. An air compressor, a plurality of combustors that mix and burn the compressed air and fuel by the air compressor, a fuel control valve that collectively adjusts the fuel of the plurality of combustors, and a gas that has a means for detecting exhaust gas temperature. A gas turbine temperature control device, characterized in that in a turbine, a fuel control valve for each combustor is adjusted based on the variation in exhaust gas temperature.