JPS5948297B2 - Gas turbine intake air temperature correction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas turbine intake air temperature correction device that can maintain low fuel consumption during steady operation even when the intake air temperature of a compressor changes.

A conventional two-shaft gas turbine with a heat exchanger and its control device are constructed as shown in FIGS. 1(a) and 1(b).

In the figure, 1 is a compressor, 2 is a gas generator turbine, 3 is a power turbine, 4 is a heat exchanger, 5 is a combustor, 6
is a fuel adjustment valve, 7 is a fuel adjustment valve drive mechanism, 8 is a fuel pump, 9 is a barrier pull vane, 10 is a barrier pull vane drive mechanism, 11 is a load, 12 is a 7' accelerator pedal, 13 is a gas gene turbine target rotation speed 14 is the gas general turbine rotation speed detector, 15 is the power turbine rotation speed detector, 16 is the gas general population temperature detector, 18 is the converter, and 19 is the fuel barrier pull vane control device. This will be explained later.

This control device 19 is suitable for gas turbines for vehicles and has the following functions.

(b) Carry out steady-state operation on the fuel plan line determined to maintain low fuel consumption.

(b) Improving rapid deceleration performance.

(c) Prevent overheating of materials due to excessive fuel injection and prevent overspeed of rotating parts due to power imbalance.

An example of a control device that satisfies all of the functions (a), (b), and (c) above is shown in Figures 2a and 2b.

In the figure, the parts 1 to 18 are designated by the reference numeral a in FIG. 1.

This is common to b.

20.23.32.38.41.44 is a comparator, 29.
35. 39 is an adder, 21 is a gas general rotation speed governor, 2
2 is a target rotation speed setting device for the power turbine, 24 is an overspeed protector for the power turbine, 25 is a function generator (fuel planning line during steady operation), 26 is a function generator (maximum fuel line during acceleration), and 27 is a power turbine overspeed protector. Similarly, there is a function generator (gas zero inlet temperature calculation line during steady operation), 28 is a gas generator inlet temperature margin setting device, 30 is a temperature protector, 31 is a phase lead compensation circuit, 33 is a P operation regulator, and 34 is a minimum value selection circuit. , 36 is a blowout prevention fuel flow rate setter, 37 is a maximum value selection circuit, 40 is a PI operation regulator, 42 is a barrier pull vane opening degree regulator during sudden acceleration/deceleration, 43 is a proportional gain setter, 45 is a In the barrier pull vane opening degree determination device, a is the atmosphere and -e is the exhaust air.

The meanings of the symbols used in Figure 1 a, b and Figure 2 a, b are described below.

N6*: Target value of gas general rotation speed during steady operation, N6D: Gas general rotation speed at design point, N6: Measured value of gas general rotation speed, N-: Target value of power turbine rotation speed during steady operation (overspeed prevention), NP,: Power turbine rotation speed at design point, N:
Power turbine rotation speed measurement value, T7*: Gas zero inlet temperature calculation line during steady operation, T7: Gas general inlet temperature, T7: Gas general population temperature measurement value, T7MOD: Gas zero inlet temperature calculation line after phase lead compensation, T7maX: Turbine material Endurance limit temperature, ΔT
: Gas zero inlet temperature calculation line, Gf5: Planned fuel flow rate during steady operation, ΔGrmax: Maximum value of fuel flow rate change (prevention of overheat surging) Gfmin: Fuel flow rate to prevent blowout during sudden deceleration, G, :! Flow rate, ■6: Variable vane opening (design point standard) vcmax
: Barrier pull vane opening degree upper limit, vcm+n :
Barrier pull vane opening lower limit value, ■□: Barrier pull vane opening during steady operation, ■N: Barrier pull vane opening during sudden acceleration/deceleration, Δ: Sudden acceleration/deceleration judgment criteria, Above (a), (b), The fuel flow rate is G as shown in Figure 2 (b), and the maximum fuel line sandwiching the 5th line (to prevent overheat surging during sudden acceleration) is G to fully satisfy the function (c).
fma X-ray and minimum fuel line (to prevent blowout during sudden deceleration) G
In the range of the fmin line, proportional control is performed with a droop of α% with respect to the design point.

The maximum fuel line GrmaX line is intended to prevent overheating or surging during sudden acceleration, and the minimum fuel line Gfmin line is set with the intention of maintaining air fuel efficiency to prevent blowout during sudden deceleration.

During sudden acceleration/deceleration, the regulator 42 is activated to improve sudden acceleration/deceleration performance.
The barrier pull vane 9 is suddenly opened and closed depending on the degree of sudden acceleration/deceleration.

At this time, the dead band (±Δ) of the regulator 42, the gain of the proportional adjustment section, the upper and lower limits, and the proportional gain setter 43 are set to appropriate values.

Further, the PI controller 40 is provided on the gas zero inlet temperature calculation line during steady operation.

A feedback loop constituted by the adder 39 and the barrier pull vane opening degree determiner 45 has a limiter function to keep the barrier pull vane opening degree signal VG within the range of the upper limit value ``Gmax'' and the lower limit value ``Gm1o''.

To prevent overheating, measure the gas general population temperature T7 by adding a margin ΔT to the target value T7' of the power supply general inlet temperature during steady operation determined by the gas general rotation speed N6, and then cutting the upper limit at the durability limit temperature T7maX of the material. This is done by reducing the fuel flow rate in proportion to the amount by which the value T7mOD (result of phase lead compensation) exceeds this set line.

The T7* line is a gas zero inlet temperature calculation line determined so that the operating point is on the maximum efficiency line on the compressor map during steady operation.

The converter 1 18 is for converting a signal in the control device into an operation signal for the fuel adjustment valve drive mechanism 7 and the barrier pull vane drive mechanism 10.

The conventional control device with the above-described configuration and operation has a plot line T7'' of the inlet temperature of the gas general turbine 2 as shown in the function generator 27 of FIG. (-N.

), the steady operating line of the compressor map L will deviate from the maximum efficiency line of the compressor 1 due to a change in the intake air temperature TI of the compressor 1.

The intake air temperature T1 is always at the set value Too (for example, +1
5℃), then the T7” line of the population temperature planning line is the actual rotation speed N.
Even if it is set as a function of
ID), which coincides with the maximum efficiency line of the compressor.

Assume now that the intake air temperature T1 of the compressor 1 is the set value and the operating point is at point 8 on the compressor map (Fig. 3).

Here, it is assumed that the gas general rotation speed N6 (=NC) is constant and the intake air temperature T1 has fallen below the set value T11).

The corrected flow rate ratio and corrected rotational speed ratio of the compressor 1 or, respectively, is expressed by:

From equation (2), if TI<TID, the nettle will increase.

As a result, the operating point, which was at point S in Figure 3, moves to point SB, and the steady operating line changes to line B.

Similarly, if the intake air temperature T1 rises above the design value T1D, then from equation (2) (2) decreases, and the operating point becomes 8 in Figure 3.
As the point moves from the point to the 86th point, the steady operation line changes to the C line.

Therefore, even if the intake air temperature T1 is lower than or equal to the design value T1D, the steady-state operating line will deviate from the maximum efficiency line of compressor 1 (line A in Figure 3), and the steady-state fuel efficiency of the gas turbine will deteriorate. There are drawbacks.

In FIG. 3, the suffix D for the modified flow rate ratio indicates the value at the design point.

Further, the operating line A is made to coincide with the maximum efficiency line of the compressor.

The present invention was made with the aim of eliminating the drawbacks of the conventional two-shaft gas turbine control system with a heat exchanger, and even if the intake air temperature of the compressor changes from the design value,
It is necessary to make corrections for changes in intake air temperature so that the steady operation line on the compressor map matches the maximum efficiency line of the compressor, and to maintain the fuel consumption as low as possible during steady operation. was set as a function of the actual rotation speed N6, but is now set as a continuous function of the deviation (TI-TLD) of the compressor intake air temperature from the set value, and a correction signal generator 54 generates a correction amount N6N of the gas general rotation speed. (Fig. 5), and this correction amount N6o
The present invention is characterized in that a function generator 56 is provided which generates a planned value T7'' of the gas general population temperature as a function of the addition result N,' of the actual rotational speed N, and the actual rotational speed N.

Here, how to define the human output relationship of the correction signal generator 54 will be explained.

From equation (2), N, -- under certain conditions N-
■From the thing on the right, the change in compressor intake air temperature T,
-T.

The change in rotation speed ΔNo is ΔNoCc, l”i −T1゜ It is.

Using this point, change the correction amount N6o to Nco=+JtakeTI
Give as D.

However, K1 shall be determined appropriately according to design conditions.

In addition, for the human output relationship of the function generator 56, the gas generator rotational speed N6 and the gas seven population temperature planned value 'F7* at the design point are used.

Hereinafter, specific examples of the intake air temperature correction device of the present invention will be described in detail with reference to the accompanying drawings.

The structure of the present invention is shown in FIGS. 4a and 4b and FIG. 5.

FIG. 4a shows the relationship between the correction device shown in FIG. This is different from Figures 1a and b in that it is used.

The present invention replaces the function generator 27 shown in FIG. 2a with the circuit shown in FIG. 5, and aims to maintain low fuel consumption during steady operation regardless of the intake air temperature.

The names of each element in Figure 4 (b) and Figure 5 are listed below.

However, element parts 1 to 26 and 28 to 45 are shown in FIG.
b. This is the same as Fig. 2 a and b, so it will be omitted.

51 is a compressor inlet temperature detector, 52 is a reference compressor population temperature setting device, 53 is a comparator, 54 is a gas generator rotation speed correction signal generator, 55 is an adder, and 56 is a function generator (gas generator is turned on during steady operation) temperature planning line).

Next, the meanings of the symbols used in FIGS. 4a, b and 5 are described below.

T1: Compressor inlet temperature, T1: Measured compressor inlet temperature, T, D: Reference compressor inlet temperature, N6C: Gas general rotation speed correction signal, N6]: Corrected gas general rotation speed, Next, the intake air temperature control of the gas turbine of the present invention The operation of the device will be explained.

The inlet temperature T1 of the compressor 1 detected by the temperature detector 51 is led to a comparator 53, where it is compared with the output T1D of the reference temperature setter 52, and a deviation signal τ1-T1D is sent to the correction signal generator 54.

The correction signal generator 54 calculates the intake air temperature deviation TI TID
According to the magnitude of the gas-zee/rotational speed correction signal N6o
is generated and sent to the adder 55.

When the correction signal generator 54 is T1>TID, N6o>
When 01TID<TID, N, < 0, T1-T
In the case of lo, a signal with N6o=0 is output.

Adder 55 adds output N6 of gas general rotation speed detector 14 and output N6C of correction signal generator 54, and sends signal N6' to function generator 56 as corrected gas general rotation speed N6I.

The function generator 56 outputs a planned value T7* of the gas generator inlet temperature in response to the input signal N6'.

As a result, this gas general inlet temperature planned value T7* takes a value of 81 points when the intake air temperature is low and a value of 82 points when the intake air temperature is high for the same gas general rotation speed N6 as shown in Fig. 6. .

When the intake air temperature T1 is lower than the reference temperature T1D, as described above, N6o<O, so N6'<N6.

Then, the gas general inlet temperature planned value T7* moves from point S to point 81, as shown in FIG. 6, and the planned value T7* is decreased.

Therefore, the comparator 38, the adder 39, the PI operation regulator 4
0, comparator 44 and barrier pull vane opening degree determiner 45
The barrier pull vane control circuit generates a signal to open the barrier pull vane 9 so as to lower the gas generator inlet temperature T7.

By opening the barrier pull vanes 9, the compression ratio W of the compressor 1 becomes smaller.

As a result, if the intake air temperature correction circuit consisting of the compressor population temperature detector 51, the reference compressor inlet temperature setter 52, the comparator 53, the gas general rotation speed correction signal generator 54, and the adder 55 is not provided, The operating point, which was at the SB point, moves in the direction in which the corrected rotational speed ratio N - corrected flow rate north on a constant line - increases.

Now, by appropriately determining the input/output relationship of the correction signal generator 54, the operating point can be moved to point SB' on the maximum efficiency line of the compressor.

For reference, point S in Figure 6 corresponds to point S in Figure 3, point 81 corresponds to point SB' in Figure 3, and point 81 corresponds to point SB' in Figure 3.
2 points are S in Figure 3.

′ point. Contrary to the above, if the intake air temperature T1 is higher than the reference temperature T1D, the gas general inlet temperature planned value T
7* moves from point S to point 82 in Figure 6, so comparator 3
8. A barrier pull vane control circuit consisting of an adder 39, a PI operation regulator 40, a comparator 44, and a barrier pull vane opening degree determiner 45 generates a signal to close the barrier pull vane 9 so as to raise the gas generator inlet temperature T7. .

By closing the barrier pull vanes 9, the compression ratio of the compressor 1 increases.

As a result, if no intake air temperature correction is performed, S in FIG.

The operating point at point S61 moves on the corrected rotation speed ratio N, -- constant line in the direction in which the corrected flow rate ratio decreases, so the operating point should match point S61 on the maximum efficiency line of compressor 1. I can do it.

According to the gas turbine intake temperature correction device of the present invention, the compressor inlet temperature is detected and compared with a reference temperature, and if it is lower than the reference temperature, the corrected gas general rotation speed N6
' is the actual rotation speed N.

If the temperature is higher than the reference temperature, the corrected gas general rotation speed N6' is made larger than the actual rotation speed N6, and the planned value T7* of the gas general population temperature is corrected to improve the efficiency of the steady operation line on the compressor map. Can be matched to the maximum line.

As a result, there is an excellent effect in that fuel consumption during steady operation can be maintained at a low level even if the intake air temperature changes.

[Brief explanation of the drawing]

Fig. 1a is a circuit diagram of a conventional two-shaft gas turbine with a heat exchanger, Fig. 1 is a circuit diagram of its control device, Fig. 2a is a circuit diagram showing an example of a conventional control device, Fig. 2 Fig. 3 is a chart showing the range of the conventional maximum fuel line and minimum fuel line, Fig. 3 is a chart showing that the steady operating line on the compressor map changes due to changes in the intake air temperature of a conventional compressor, and Fig. 4 a
4 is a circuit diagram showing the relationship between the gas turbine intake air temperature correction device of the present invention and the gas turbine main body, FIG. 4 is a direction diagram of the correction device of the present invention, and FIG. 5 is a diagram showing the function generator of FIG. 2a. FIG. 6 is a circuit diagram of the present invention which outputs a planned value of the gas general inlet temperature by replacing the gas generator. 1... Compressor, 2... Gas generator bin, 3... Power turbine, 4...
... Heat exchanger, 5 ... Combustor, 6 ...
・Fuel adjustment valve, 7...Fuel adjustment valve drive mechanism, 8
... Fuel pump, 9 ... Barrier pull vane, 10 ... Barrier pull vane drive mechanism, 1
1...Load, 12...Accelerator pedal, 14...Gas generator turbine rotation speed detector, 1
5...Power turbine rotation speed detector, 16...
...Gas Zenejin ['Temperature detector, 1 Otsu 18...]
...Converter, 28...Gas general population temperature margin setting device, 29.55...Adder, 38.5
3...Comparator, 51...Compressor inlet temperature detector, 52...Reference compressor inlet temperature setter, 54...Gas general rotation speed correction signal generation 56...Function generator.

Claims (1)

[Scope of Claims] 1. A 12-shaft gas turbine that is controlled according to a gas generator inlet temperature planning line set as a function of the gas generator rotation speed so as to be able to operate at steady state on the compressor's maximum efficiency line. Then, there is a circuit that detects the compressor inlet temperature, compares it with the reference inlet temperature, and calculates the temperature deviation, and continuously adjusts the amount of correction of the gas general turbine rotation speed according to the sign or the negative of the temperature deviation and the magnitude. The desired circuit and
This circuit adds the output of this circuit and the actual rotational speed of the gas general turbine to determine the corrected gas seven non-rotating speed, and generates a function that gives the corrected gas seven non-rotating speed the planned value of the gas general and turbine population temperatures. Give it as a human power signal of the device. A gas turbine intake air temperature correction device characterized in that steady-state operation is maintained on the maximum efficiency line of the compressor by correcting changes in the intake air temperature of the compressor.