JPS5847125A - Fuel control device of gas turbine - Google Patents

Abstract

PURPOSE:To provide possibility to transfer into override control immediately when either of the turbine acceleration and exhaust gas temperature as feedback element has exceeded its preset value, by using a velocity type proportional integrator in the override control system. CONSTITUTION:Velocity type proportional integrators 16, 18 are used in an acceleration and a temp. control system, respectively, to constitute an override control system, and when either of the turbine acceleration and exhaust gas temp. as feedback element exceeds their respective preset values, it shall be sensed off immediately to place out any smallest value among those signals from the override control system, i.e. fuel control signal ACC (PIV) and TEMP (PIV), as a fuel adjuster valve control signal CFF through low-value priority circuit 31, integrator 33 and analog switches 34, 35. Change-over to the main control system is made at the point of time when comparison of the output of the integrator 33 with the analog switch output of fuel control signals CFF (SRT) and CFF (GOV) from the main control system gives a result that the fuel control signal is smaller than the output of integrator.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is configured so that when it is detected that either the turbine acceleration or the exhaust temperature is larger than a set value as a feedback amount, the suppression control can be immediately performed. The gas turbine fuel control system is configured with v14f.

In gas j-pin power generation, the amount of fuel flowing into the fuel ms is controlled, but in the past, acceleration jI! When shifting to O control or temperature control, there is a problem in that the control becomes uneven, and as a result, it is not possible to suppress a sudden increase in acceleration during temperature control.

In other words, in gas turbine power generation, as shown in Figure 1,
The pressurized air from the compressor 1 is heated by combustion 1iI2 and becomes a high-temperature gas, which acts on the turbine 3 to turn the generator 4 and generate 1 liter of electricity generated by 1 power generation 44. The power is transmitted to the grid via the standby aS. As can be seen from this, the temperature of the gas #1k-5 supplied to the turbine 3 is the same as that of the combustor 2.
It depends on the heating temperature at *0f
itl# is necessary and remains open from the start of the turbine 3 to when it starts to work and even after it reaches a steady state of operation. This is because it is necessary to protect the turbine from sudden increases in degrees FI and to cope with load fluctuations. Temperature control is specifically about combustion*! A fuel supply f9 is connected to the combustor 2 shown in the figure, and the fuel regulating valve 7 provided in the middle of the fuel supply pipe 9 is controlled by controlling the amount of fuel flowing into the combustor 2. By controlling the fuel control device 8, j
The right amount of fuel is the key to fuel! 2.

FIG. 2 shows a block configuration of the fuel control device 8.

According to Nire, the gas turbine fuel control system is the startup control system 1.
G. Speed/load control system 11. Acceleration control system 12, temperature Fi
It is roughly divided into t control system 13. Among these, the startup control system IO controls the amount of fuel according to a predetermined startup program signal when starting the gas turbine, and prepares the gas turbine to start up to the rated speed. It was. Speed/load control system 1
1 is for controlling the speed and load after the gas turbine reaches its rated speed. These two control systems are related to the control that occurs. On the other hand, f
The acceleration control system 12 and the degree control system 13 perform override control, and function to suppress the main control and protect the turbine.

Among these, the acceleration control system 12 is a round type that controls the turbine acceleration at startup so that it does not exceed a set value, and the temperature control system 13 is a round type that controls the life of the vertical part of the turbine. When starting the gas turbine, the temperature change rate in that part does not exceed the set value, and during load 4, it is a large one that controls flA firing a* so that it does not exceed the set value. . The fuel control signal from the bone control system is selectively outputted to the switching gate 14 according to the rotation of the turbine 1, so that the fuel g! 1 valve 7 is controlled.

By the way, conventionally, by using a low value priority circuit in the switching gate 14, the lowest value among the auto fuel control signals is selectively outputted to the fuel pot valve 7. A disadvantage of using the priority circuit is that there is a threshold deviation when switching between acceleration control and degree control.

This is because the output of the ratio integrator under acceleration control and single-direction control is saturated if the feedback amount is smaller than the set value. Rounding to switch to acceleration control requires the output of the integrator to fall below the saturation value, and it takes an integration time for it to drop, so it is not necessary to immediately turn on the turbine. The idea is to suppress the rise in temperature and keep it at a minimum.

Therefore, an object of the present invention is to provide a gas turbine control device which can immediately shift to override control when either the turbine speed or the exhaust temperature, which is the amount of feed/cooling, becomes larger than a set value. .

For this purpose, the present invention uses a speed-type proportional divider in the ride control system, so that either the turbine acceleration or #fi temperature, which is the amount of load, is larger than the set value. In case of 9, it will be detected immediately and 1g will be given priority over low 1.
The fuel control signal from the override control system is outputted for fuel valve control via the L path and the integral. In addition, in the present invention, over 2 id 1tl
Switching from the llll system to the control system is performed by comparing the output of the upper ml integrator with the fuel control signal from the main control system, and at the point in time when the fuel control signal becomes smaller than the integrator output. When switching in this way, the fuel #
This is because the fuel control signal for the ui valve is not switched in a discontinuous manner, and therefore there is no daylight associated with the switching.

The present invention will be explained below with reference to FIGS. 3 to 5.

First, the configuration of the three control systems including the starting program signal as the fuel control signal outputted from the starting control system and the remaining control system will be explained as follows by referring to FIGS. . In addition, if it is substantially different from t according to the prior art, then ζ is newly compared with the set value and feedback amount in the Quido control system; a comparator is added as a requirement, and the proportional integrator is It is replaced by an lIL type ratio fl integrator.

First is the 1iAtIJ program signal, which is the third
Figure (shown in the figure, but 4 outputs are generated immediately. That is, 1 ignition signal 2T
Start program signal CF for the first time at the time of ignition by VX
F (8B?) must be raised to a certain value for ignition,
When the ignition confirmation signal 211FDX is obtained, the amount of fuel is temporarily reduced to the warm-up fuel amount for a certain period of time. From the moment the III machine end signal 2WX, which is output from the timer upon completion of the warm-up, is obtained, the start program signal 0F is automatically activated.
By gradually increasing F(8R, T), the turbine t is brought into a bad state at the rated rotational speed.

Next, we will explain the configurations of the speed/load control system, acceleration control system, and temperature control system.
6) to (d). The speed/load control system is configured as shown in the figure (the deviation fIi between the governor setting position and the turbine speed as a feedback amount is calculated proportionally by the proportional calculation element 15, and the fuel value at no load is added to this). Fuel control signal CFF during rated speed trend
(GOV). In addition, the acceleration control system and the 1!1 FIt city ttm system have almost the same nI configuration, and the deviation between the set value and the feedback amount O turbine speed and exhaust temperature is calculated using the speed type proportional integral O1 calculation.
6.18, and the calculated outputs are used as fuel control signals ACC (PIV) and TEMP (PIT). The input/output relationship in the velocity type ratio integral calculation element 16.18 is as shown in FIG.

Y=K (X-X-,)+X'l' s /T *However, Tm is the sampling J4 period, TI is the proportional gain for integral gain %, and X-1 is the front 61 knob ring 1 shift.

The difference between these acceleration control systems and the one-degree control system from those of the prior art is that the Bonparator 17.19
is newly established. When the amount of feedback is larger than the set value, the threshold value is set so that the high level foreshadowing signals ACC and TIMF are output.These signals CC and TR are output.
This is why the MF becomes horizontal 1 as an immediate override control request signal, which will be described later.

Now, the present invention will be explained using jl14 d(a), (11). First, the general operation of the control device according to the present invention is as follows.

In other words, the master signal MgTR cannot be obtained while the operating conditions of the turbine are not satisfied, and therefore the analog switch 35 as an analog/4G multiplexer uses the direct voltage signal KU0> as fuel, ill! It is configured to output a fuel-both signal CPF to the valve.

Therefore, no fuel is supplied to the combustor while the mater signal MaTR is not obtained. The analog switch 35 is configured as shown in FIG. 5 (11) (A selection input 8wO*
If the fi level is in a so-called low level state, input
1 is selectively outputted as output Y, but Q is output as h. This situation is the same for the analog switches to be described later.

Now, the threshold at which the turbine is activated when the operating conditions of the turbine are satisfied is that Tanibin is suitable for the rated speed.
Since the signal GOVERNING% obtained by extending %IN to the timer 24 is also not obtained, the turbine is 71ii! - As a general rule, wake up while it is inside! Fuel from IJ & system - both signals 0FF (8RT)
is applied to the fuel control valve via the analog switches 29, 34 and 35 to turn off the fuel control i1. When the pin speed eventually reaches the rated state by the start control, 100% N of No. 171 is obtained continuously from then on,
Therefore, the signal GOVERNING is also delayed and is available continuously in the foreground, but the signal GOVIRN
ING is obtained, and from the 9th point onwards, the fuel control signal OFF (GOV) from the speed/negative control system is turned OFF (another eye switch 2).
9.34.35 Fuel control to the fuel valve No. 1H O
It becomes FF.

By the way, if the need for override control arises while the above-mentioned control is being carried out, that fact is stored in the 7-rip 70 block (AND gate 22 and OR gate 23). If the feedback amount becomes larger than the set value p in any part of the flange system, this fact is detected by the horn palletators 17 and 19.

Therefore, from the time when the machine end signal 2WX is obtained, either comparator 17 or 19] No. 18 Ac to that effect
e, if Tibi-p is obtained, or gate 2
0. Through the AND gate 21, the 70 knobs are set to the set state, and 1tlll# shifts from the main control to the geoparite control. Since the set output signal TEMP of 7 rip 70 tug is input, the analog switch 34 outputs the fuel control signal from the override control system. 04 rate # signal ACC (PIV), TEMP from the override control system
(PIV) 05 et al. 1 small 540 # low 1 [f destination IQ 114
I31.

゛Integrator 33. The fuel control signal is given as OFF to the fuel-fuki valve via the analog switches 34 and 35, but in this case, the input signal to the integral a33 is the signal TgMP.
-, #ed by +person CC.

As shown in the figs (C), the integral aaa integrates the input X when the ii-type human power 8w is in a low level state, and integrates the force X when it is in a high level foreshadowing state. . Therefore, while the signal TEMP+muCC is not obtained, the integral aaa is the addition offset tJE
Signal 0FFf9]1i:T is added and integrated round) is in 7op-7op mode.

If the signal TEMP + human CG is 4b in such a state,
411I divider 33 outputs low 1 instead of the output from adder -32.
The oniparide control system fuel control signal from the direct priority circuit 31 is integrated with the integrated value up to that point as the vJ period value.

The transition to the override control is as described above, but the transition to the primary control (override rlIl#) is performed by the comparator 30. ':5yAv-taper 30 generates an initial change set signal (LaBT) at the time of turbine startup, and forcibly resets the above-mentioned trip log.
It is detected that the output from the integral a33 is larger than the m control system fuel control signal from the analog switch 29, and the condition for transition to the control that occurs in Kubacha is determined to be 111i.
By generating the Il switching signal (GOV), the set state jllK6 and 7 lip flops are reset.

That is.

Comparator 30 or signal 8BT+GOV by 7
The lip log is reset], and whether it is the main control or the override control is determined depending on the state of the lip '70.

If the output of the OR gate 20 were to be used to control either the main control or the override control, the control switching would occur every four times, or in some cases, a hunting phenomenon would occur, but in the case of IIm as described above, Such ineligibility can be avoided. What is important in transitioning to a control system developed as described above is that there is no shock associated with control switching and that control switching can be performed smoothly. This is obvious from the comparison principle of the comparator 30. Furthermore, the relationship between acceleration control and temperature control can be changed without shock. This is because the speed PR type proportional integral calculation output is switched by the low value priority circuit 31 equipped with a control panel.

In addition, the code 27.2L 4G, 41 is for water, acceleration system # mode display, 11 degree control mode display o't
A signal FIRING indicating that the fuel is actually burning in the combustor is obtained, indicating the ta indication.

, moreover, it is detected by AND GO 25 that TEMP+MUCC, GOVERNING is not obtained, and the detection output is output to drive the display 27 for displaying the activation control layer. 26 is No. 11 GO on the display 28 for displaying the load control mode.
VIi: RNING power is obtained, and the signal TIMF+
When it is detected that the person CC is not obtained, the driving display is set to 5. On the other hand, the display for indicating the acceleration control mode and the temperature control mode 1) 40.4
10JI#The truth is.

Is the fuel control signal output from the low value priority circuit 31 to the monitor relay 36.3'l related to acceleration control?
t control is detected, and these detection outputs and the signal T
l! AND gate 38,3 that uses MP 1500 as a logical term
This is because it is performed by the output of 9.

As explained above, the present invention uses the IILf# proportional-integral calculation element in the overriding control system, and detects the need to switch from the main control to the shear-operated control at the 9th point in time. ] The switching to the main control is performed when the fuel control signal related to the override control becomes larger than that related to the main control.
It consists of 9 things and 6 things. Therefore, in the case of the present invention, unlike the conventional case, when either the turbine acceleration or the exhaust 1 degree, which is determined by the ride pack amount, becomes larger than the set value, the effect can be shifted to the override control immediately. There is.

[Brief explanation of the drawing]

jl1 figure t! , Figure #12 is a diagram showing a general system configuration of a cast turbine power generation system, Figure #12 is a diagram showing a general configuration of a conventional fuel control device # in the system configuration, Figures 3-) to (d) are each of the following: The same diagram (Hata) related to the main engine 11 shows the fuel control signal obtained from the starting control system, gI (iI ~ φ) is the straightening/speed load control system, acceleration control system, a degree, respectively. Figure %44 showing the configuration of the control system (
al), (- is an example of the gas turbine fuel control device according to the present invention and indicates O#l configuration.
This is a factor for explaining the functions of the main circuit components in FIG. 4 (6). Is-proportional calculation element, 16.18-speed * type proportional integral calculation 11: lth I L 19e 30・”: xy palator. 24-/(-1m 29, 34.36-1tH/X one, lx-・low Value priority circuit, 3g - 4 minutes - 0 generation salt input Benshoshi Masaaki Akimoto Figure 1 Figure 2 @J1L-1 Figure 3 Figure 4 (a-)

Claims (1)

[Claims] 1. A control system that programmatically generates a fuel control signal at the time of turbine start-up. A proportional calculation is performed based on the deviation between the control system and the turbine speed. In the load control system, the difference between the set value, the turbine acceleration, and the exhaust temperature is calculated by the speed type proportional-integral factor, respectively), and the turbine acceleration,
The ninth fuel d# (including the acceleration control system and temperature control system that generates No. 1 is selected according to each of the above-mentioned control systems and response O fuel control signals, and any one of the nine is selected to produce the fuel
A gas turbine fuel control system that controls the amount of fuel flowing into the gas turbine fuel control system detects the fact that the turbine acceleration tL and exhaust 1 degree are larger than the set values in the acceleration control system and the 1 degree control system, respectively. a12 comparator is provided, while the fuel 11 obtained from the start control system and the speed/load control system is provided.
Il#11f# to the second i through @1 multiplexer
one input of the multiplexer, and the output of the second multiplexer and the fuel control system 1411i of the acceleration control system and 11iLk11tIl- system via the priority circuit.
I is connected to the other input of the multiplexer 2 through the integrator, and a comparator detects that the output of the integrator is larger than the output of the multiplexer 41, and the comparators 11 and 12 4 integral inputs in the above integrator, the second ! By selectively controlling the multiplexer output, the second multiplexer? Gas turbine 6% control device, characterized by a configuration obtained as Fuel@m (No. 11), which controls the amount of fuel flowing into the combustor,