JPS6151134B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas turbine control device, and more particularly to a gas turbine rotation speed setting device.

Figure 1 shows one type of gas turbine,
1 shows a conventional two-shaft gas turbine with a heat exchanger and its control device. That is, in the conventional two-shaft gas turbine, air from the atmosphere is compressed by the compressor 1, heated by the heat exchanger 4 with exhaust heat, and guided to the combustor 5. Fuel from a fuel pump 8 is supplied to the combustor 5 via a fuel regulating valve 6 controlled by a fuel regulating valve drive mechanism 7, where it is combusted. The combustion gas generated in the combustor 5 first drives a gas gene turbine (hereinafter abbreviated as gas gene) 2, then drives a power turbine 3 via variable vanes 9, and is then discharged via a heat exchanger 4. Ru. The output shaft of the power turbine 3 is linked to a load 11 . Reference number 14 is a gas generator rotational speed detector, 15 is a power turbine rotational speed detector, 16 is a gas generator inlet temperature detector, 17 is a compressor intake air temperature detector, and 10 is a variable vane drive mechanism. This two-shaft gas turbine is controlled by the above-mentioned fuel adjustment valve drive mechanism 7 and variable vane 9 drive mechanism 10, and the control device, that is, the fuel/variable vane control device is designated by reference numeral 20.

The fuel/variable vane control device 20 obtains the gas general rotation speed setting value N _G during steady operation outputted from the gas general rotation speed setting device 13 according to the degree of depression of the accelerator pedal 12 and from the gas general rotation speed detector 14. a comparator 21 that receives the gas generator rotational speed measurement value N _G ; and the output of this comparator 21;
The power turbine rotation speed measurement value N _P obtained from the power turbine rotation speed measuring device 15, the gas general rotation speed measurement value N _G , and the measurement value of the gas general inlet temperature T ₇ obtained from the gas general inlet temperature detector 16 〓 ₇ , the measured value of the compressor intake air temperature T _{1 obtained} from the compressor intake air temperature detector 17 Outputs opening command signal VG and fuel flow command signal Gf. These command signals are converted into operation signals by converters 19 and 18, respectively, and supplied to variable vane drive mechanism 10 and fuel adjustment valve drive mechanism 7. This fuel/variable vane control device 20 has the function of outputting two commands as described above, and is particularly suitable for gas turbines for vehicles and has the following functions. That is, (1) Steady operation is performed along the fuel planning line and the gas generator inlet temperature planning line T ₇ 〓 determined so as to maintain low fuel consumption.

(2) Improve sudden acceleration/deceleration performance.

(3) Preventing gas turbine materials from overheating due to excessive fuel input, and preventing overspeeding of rotating parts due to power imbalance.

Generally, in a gas turbine, when the intake air temperature _T1 of the compressor 1 decreases, the weight flow rate increases for the same rotation speed, and the load on the gas generator 2 increases. For example, in the case of a gas turbine for a vehicle, from the viewpoint of operability, it is desirable that the engine output is not affected by changes in external conditions such as intake air temperature. In other words, it is desirable to be able to obtain a constant operational feeling (correspondence between the operation of the accelerator 12 and the power turbine rotation speed) regardless of external conditions.

In the two-shaft gas turbine whose structure is shown in FIG. 1, when the intake air temperature decreases, the weight flow rate of the compressor 1 increases, and if the fuel is the same, _T7 decreases. At the same time, the load on the gas generator 2 increases and its rotational speed decreases.

The "decrease in T ₇ " and the "decrease in T ₇ 〓 due to a decrease in rotational speed" are almost commensurate with each other, and the variable vane opening degree is maintained at the same level by the action of the control circuit 22, but on the other hand, The decrease in rotational speed is caused by the same accelerator position, that is, the same gas generator rotational speed setting value N.
_G 〓, and the action of the control circuit 22 causes an increase in fuel. As a result, when T ₇ recovers, the gas generator rotational speed is recovered, T ₇ 〓 and T ₇ are balanced, and the variable vane opening degree remains at the same level. Therefore, even at the same accelerator position, the output of the power turbine 3 increases in proportion to the increase in air flow rate due to a decrease in intake air temperature, resulting in a disadvantage that the operating feeling becomes incorrect. (In FIG. 3, the operating point moves from point A to point B).

As described above, the conventional control circuit has a problem in that the operability changes when the intake air temperature of the compressor 1 changes, and the present invention aims to eliminate this problem. .

According to the present invention, the intake air temperature measurement value 〓 ₁ of the compressor 1 is compared with the reference value T _1D , and the correction signal _ΔN 〓 [〓 ₁ T When _1D, ΔN = 0, = ₁
When T _1D , calculate ΔN〓∝(〓 ₁ − T _1D ) < 0〕 proportionally, add this to the gas general rotation speed setting value N _G 〓, and use the correction signal N _GC 〓 as the gas general rotation speed setting value. By doing this, even if the intake air temperature changes,
Consistent operability can be obtained.

A control device for a two-shaft gas turbine, which is a preferred embodiment of the present invention, includes a circuit (a) that compares the compressor intake air temperature and calculates its deviation, and a circuit (a) that determines the magnitude of the output of this circuit (a) (the decrease in the intake air temperature). circuit (b) that proportionally calculates the correction signal of the gas gener- ation speed setting value according to the degree of
A circuit (c) which adds the output of (b) to the gas general rotation speed setting value to obtain a corrected gas general rotation speed setting value, and compares the output of this circuit (c) with the lower limit value of the gas general rotation speed,
A circuit (d) for selecting the larger signal is added, and when the compressor intake air temperature decreases, the set value of the gas gener- ation rotation speed is corrected according to the degree of decrease in the intake air temperature, and for the same accelerator position. By lowering the gas generator rotation speed and reducing the gas flow rate, the output horsepower of the power turbine is kept constant, and the power turbine rotation speed is maintained at a rotation speed corresponding to the accelerator position, resulting in a constant operating feeling regardless of the intake air temperature. I'm trying to get that.

Hereinafter, a preferred embodiment of the present invention illustrated in FIG. 2 will be described in detail. In the control device shown in FIG.
In order to clarify the connection relationship between the elements according to the present invention and other elements, peripheral elements are also shown, and the same elements are indicated by the reference numbers of the elements in FIG. However, the gas turbine main body (elements 1 to 11) and the detection end (elements 14 to 17) are the same as in FIG. 1, so they are omitted.

The fuel/variable vane control device 20 includes a comparator 21 and a control signal calculation circuit 22, as well as a reference intake air temperature setter 51, a comparator 52, and a regulator 53.
It newly includes an adder 54, a gas generator rotational speed lower limit value setter 55, and a maximum value selection circuit 56.

The comparator 52 has its input connected to the compressor intake air temperature measurement value ₁ and the reference intake air temperature T _1D from the reference intake air temperature setter 51, and its output is connected to the controller 5.
3 to an adder 54. regulator 53
The input/output relationship is set as shown in the figure, and the gain K is set so as to maintain a predetermined operability according to the intake air temperature range in service to the gas turbine. Adder 54
is connected to receive the gas general rotation speed set value N _G from the gas general rotation speed setting device 13 and the intake air temperature correction amount ΔN from the regulator 53, and its output is connected to the input of the maximum value selection circuit 56. The maximum value selection circuit 56 also includes a gas generator rotation speed lower limit value setter 55.
Modified gas general rotation speed setting value N _GC 〓 lower limit value N
is connected to receive _G 〓min, and its output is connected to the input of a conventional comparator 21.

In terms of operation, the comparator 52 compares the intake air temperature measurement value 〓 ₁ with the reference intake air temperature T _1D set by the setting device 51 to obtain a deviation signal (〓 ₁ - T _1D ), which is sent to the regulator 53. Send. regulator 53
sends an intake air temperature correction signal ΔN 〓 to the gas generator rotation speed setting value _NG 〓 to the adder 54 according to the degree of the intake air temperature deviation (〓 ₁ −T _1D ). However, when 〓 ₁ T _1D , ΔN〓=K(〓 ₁ −T _1D ),
Further, when 〓 ₁ T _1D , ΔN〓=0. The adder 54 adds the correction signal ΔN〓 to the output signal N _G 〓 of the gas general rotation speed setter 13 to obtain a corrected gas general rotation speed set value N _GC 〓.

The correction setting signal N _GC 〓 is supplied to the maximum value selection circuit 5
6 is sent out. On the other hand, the gas generator rotation speed lower limit value N _G 〓min set by the setting device 55 is also sent to the maximum value selection circuit 56 . Maximum value selection circuit 56
sends the larger signal of the input signal N _GC to the comparator 21 as the set value of the gas generator rotation speed. Note that the lower limit value N _G 〓min is the correction signal N _GC 〓
This is set to prevent the idling speed from falling below N _GI , and normally, N _{G 〓NG} 〓
It is min.

Here, when 〓 ₁ = T _1D , a certain set rotation speed N _{GC
〓 = NG〓 = N _ _ _} Let N _P =N _P1 (operating point A at the reference intake air temperature in Fig. 3).

Now, in the state of N _G 〓=N _G1 〓, if 〓 ₁ < T _1D , the intake air temperature correction signal is ΔN〓=K(〓 ₁ −
Since T _1D ) < 0, the corrected gas general rotation speed setting value is N _GC 〓= _NG1 〓+ΔN〓< _NG1 〓.

As a result, the rotation speed of gas generator 2 is N _G =N _G2 <
N _G1 , the generated horsepower is L _G =L _G3 (<L _G2 ;L _G =
The output horsepower _{of the} power _turbine 3 is L
Since _P = L _P1 is maintained, the rotation speed is N _P = N _P1
can be maintained at (operating point C in Figure 3).
〓 Even if ₁ < T _1D , engine operability can be maintained constant without being affected by intake air temperature (dotted chain line in Figure 3). In Fig. 3, point B is the conventional example, and the relationship between each symbol is N _G1 > N _G2 , N
_P2 >N _P1 , L _G2 >L _G1 , L _G2 >L _G3 , and L _P2 >L _P1 .

As described above, according to the present invention, the intake air temperature of the compressor is compared with the reference intake air temperature, and when the intake air temperature decreases, a correction signal for the gas general rotation speed setting value is proportionally calculated according to the degree of the decrease. Then, add this correction signal to the gas generator rotation speed setting value,
As a result of finding the corrected gas general rotation speed setting value and using it as the gas general rotation speed setting value, if the accelerator position is the same as when the reference intake air temperature is reached, the actual gas general rotation speed will change according to the degree of decrease in the intake air temperature. Since the output horsepower of the power turbine can be kept constant, the power turbine rotational speed can be maintained at a rotational speed corresponding to the accelerator position. Thereby, even if the intake air temperature of the compressor decreases from the reference intake air temperature, the operability of the engine can be kept constant.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a conventional example of a two-shaft gas turbine with a heat exchanger and its control device, Fig. 2 is a diagram showing a control device according to the present invention, and Fig. 3 is a diagram showing its operating characteristics. FIG. 5 is a diagram showing compressor intake air temperature versus power turbine output horsepower, and FIG. 1...Compressor, 2...Gas generator turbine, 3...Power turbine, 4...Heat exchanger, 5
... Combustor, 6 ... Fuel adjustment valve, 7 ... Fuel adjustment valve drive mechanism, 8 ... Fuel pump, 9 ... Variable vane, 10 ... Variable vane drive mechanism,
11...Load, 12...Accelerator pedal, 13...
...Gas general rotation speed setting device, 14...Gas general rotation speed detector, 15...Power turbine rotation speed detector, 16...Gas general inlet temperature detector, 17...
...Compressor intake air temperature detector, 18, 19...
Converter, 20...Fuel/variable vane control device, 21...Comparator, 22...Control signal calculation circuit, 21...Reference intake air temperature setter, 52...Comparator, 53...Adjuster, 54... Adder, 55...
...Gas general rotation speed lower limit value setter, 56...Maximum value selection circuit.

Claims (1)

[Claims] 1 Compare the compressor's intake air temperature measurement value (〓 ₁ ) and the reference intake air temperature value (T _1D ), and when the intake air temperature measurement value falls below the reference intake air temperature value, calculate the correction signal (ΔN〓) proportionally. The correction signal is added to the rotation speed set value of the gas general turbine (N _G 〓) to obtain a correction signal (N _GC 〓), and this correction signal is used as the rotation speed set value of the gas general turbine. A rotation speed setting device for gas turbines.