JPS5949413B2 - Temperature protector circuit for dual-shaft gas turbine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a control circuit for a two-shaft gas turbine, particularly a two-shaft gas turbine for automobiles.

A conventional two-shaft gas turbine with a heat exchanger is shown in FIG. 1, and its control device is shown in FIG.

In the conventional turbine shown in FIG. 1, air taken in by a compressor 1 directly connected to a gas generator turbine 2 passes through a heat exchanger 4 and is warmed, then enters a combustor 5, where a fuel pump 8 adjusts the fuel. The fuel supplied via valve 7 is combusted.

The combustion gas generated here is guided to the gas generator turbine 2 to do work.

Gas leaving the gas generator turbine 2 enters the power turbine 3 via a barrier pull vane 9, performs work there, and then passes through a heat exchanger 4 and is discharged as exhaust gas.

The output shaft of the power turbine 3 drives the load 11, and the rotation speed NP of this shaft is detected by the power turbine rotation speed detector 15 and input to the fuel/barrier pull vane control device 19.

Further, the gas general turbine rotation speed NG is detected by the detector 14 and similarly input to the fuel/barrier pull vane control device 19.

On the other hand, the gas general turbine inlet temperature T7 is detected by the gas general turbine inlet temperature detector 16, and the measured value T7 is also
It is input to the barrier pull vane control device 19.

Further, the gas general turbine target rotation speed Nf set by the gas general turbine target rotation speed setting device 13 linked to the accelerator pedal 12 is also input to the fuel/barrier pull vane control device 19 .

Further, the compressor inlet temperature T1 is detected by a detector 51, and the measured value T1 is input to the fuel/barrier vane control device 19.

The barrier pull vane opening iVG generated by the fuel/barrier vane control device 19 reaches the barrier pull vane drive mechanism 10 via the converter 18, and this mechanism 10 controls the barrier pull vane 9.

Further, the fuel flow signal Gf generated by the fuel/barrier vane control device 19 reaches the fuel regulating valve drive mechanism 7 via the converter 17, and the valve 6 is controlled by this mechanism 7.

Details of this conventional fuel/barrier pull vane control device 19 are shown in FIG.

That is, the gas general turbine rotation speed target value NG from the gas general turbine target rotation speed setter 13 during steady operation is input to the comparator 21 .

The other input of this comparator is the gas general rotation speed measurement value NG from the gas general turbine rotation speed detector 14.

The output of this comparator 21 enters the gas general turbine rotation speed governor 22, and the gas general turbine rotation speed governor output ΔGf
N enters the minimum value selection circuit.

Gas generator rotation speed target value during steady operation from setting device 13 NG
input into the target rotation speed setting device 23 of the power turbine,
The power turbine rotational speed target value Np'' during steady operation, which is the output of the setting device 23, is input to a comparator 24, where it is compared with the power turbine rotational speed measurement value from the power turbine rotational speed detector 15.

The output of this comparator 24 enters the power turbine overspeed protector 25, and the output ΔG of this protector 25 is
fP enters the minimum value selection circuit 35.

The gas general rotation speed measurement value NG from the gas general turbine rotation speed detector 14 enters the maximum fuel line speed generator 27 during acceleration, and is the output of this function generator 27.

The maximum value ΔGf m a X of the fuel flow rate change is entered into the minimum value selection circuit 35.

This is to prevent overheating and surging.

The gas general turbine rotational speed measurement value Nc is determined by a compressor inlet temperature detector 51, a reference compressor inlet temperature setting device 5λ comparator 53, a gain setter (gas general turbine rotational speed correction signal) 54, an adder 55, and a function Generator (
The gas general turbine inlet temperature during steady operation, which is the output of the function generator 56, is guided by a circuit that calculates the planned value of the gas general turbine inlet temperature during steady operation, which is configured by a gas general turbine inlet temperature planning line during steady operation (56). The target value T- enters the adder 29.

The other input of this adder 29 is the gas general turbine inlet temperature heating margin ΔT from the gas general turbine inlet temperature superheating margin setting device 30.

The output of adder 29 enters temperature protector 31 and its output enters comparator 33.

The other input of the comparator 33 is the gas general turbine inlet temperature measurement value T from the gas general turbine inlet temperature detector 16.
7 is the measured value T7C of the gas generator turbine inlet temperature after phase lead compensation obtained through the phase lead compensation circuit 32.

The output of the comparator 33 enters the P operation regulator 34, and the output of the regulator 34, the gas generator turbine inlet temperature protector output ΔGfT, enters the minimum value selection circuit 35.

The fuel flow rate change Δq, which is the output of the minimum value selection circuit 35, is input to the adder 36, where it is sent from the gas generator turbine rotation speed detector 14 to the fuel planning line function generator 26 during steady operation. It is added to the planned fuel flow rate Gfs.

The output of adder 36 enters maximum value selection circuit 38.

Further, the planned fuel flow rate GfS during steady operation is passed through the blowout prevention fuel flow rate setter 3γ to obtain the fuel flow rate Gfmin for preventing blowout during sudden deceleration, which is input to the maximum value selection circuit 38 described above.

The output of the maximum value selection circuit 38, that is, the fuel flow rate Gt is the first
It reaches the fuel regulating valve drive mechanism γ via the converter 1γ shown in the figure.

On the other hand, the signal 〒7 from the gas general turbine inlet temperature detector 16 enters the phase lead compensation circuit 32 as described above, and the gas general turbine inlet temperature measurement value Tic after phase lead compensation from this circuit 32 is sent to the comparator 39. to go into.

The other input of this comparator 39 is the gas generator pin inlet temperature during steady operation obtained from the circuit (51 to 56) that calculates the planned value of the gas generator pin inlet temperature during steady operation, taking into account the effect of the intake air temperature T1. The target value is T7.

The output of the comparator 39 reaches an adder 40, where it is added to a signal from a barrier pull vane opening degree determiner 45, which will be described later.

The output of the adder inputs the pI operation regulator 41, and the output of this regulator 41 is the barrier pull vane opening degree V during steady operation.
T enters comparator 44.

On the other hand, the gas general rotation speed target value NG during steady operation from the gas general turbine target rotation speed setting device 13 is compared with the gas general rotation speed measurement value Nc from the gas general turbine rotation speed detector 14 in the comparator 42, The output is led to a barrier pull vane opening degree adjuster 43 during sudden acceleration/deceleration, and the output of this regulator 43, the barrier pull vane opening degree VN during sudden acceleration/deceleration, becomes the other input of the comparator 44 described above.

The barrier pull vane opening degree VG, which is the output of the comparator 44, is input to the above-mentioned determiner 45, and is also input to the converter 18 (
1) to the barrier pull vane drive mechanism 10.

The fuel/barrier vane control device 19, as a gas turbine control device for a vehicle, has the following functions: (1) Perform steady state operation on a fuel plan line determined to maintain low fuel consumption.

(2) Improving sudden acceleration/deceleration performance.

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

In order to satisfy all of the functions (1) to (3), the fuel flow rate should be set at the maximum fuel line (Gfma) across the GfS line shown in Figure 3.
X-ray) and the minimum fuel line (G4min line), and is proportionally controlled with a slope of α% based on the design point.

The Gfma X-ray is intended to prevent overheating or surging during rapid acceleration, and the Gfmin line is intended to maintain the air-fuel ratio to prevent blowout during sudden deceleration.

During sudden acceleration/deceleration, the regulator 43 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 zone ±Δ of the regulator 43, the gain KN, NN of the proportional adjustment section, the upper and lower limits VNmax, VNm
It is assumed that in is set to an appropriate value.

Further, the P controller 41 is provided for controlling the gas generator inlet temperature during steady operation.

A feedback loop constituted by an adder 40 and a barrier pull vane opening degree determiner 45 divides the barrier pull vane opening degree signal VG into an upper limit value VGm a x and a lower limit value vGm.
It has a limiter function to keep it within the range of in.

Regarding prevention of overheating and surging during sudden acceleration,
The upper limit of the line obtained by adding the superheat margin ΔT to the gas generator turbine inlet temperature target value TF during steady operation determined by the gas generator rotation speed NG is the durability limit temperature of the material TTma! This is done by reducing the fuel flow rate in proportion to the amount by which the measured value of the gas generator inlet temperature (result of phase lead compensation) T7c exceeds this set line.

The TF line is a gas gene turbine inlet temperature planning line determined so that the operating point is on the maximum efficiency line on the compressor map during steady operation.

The converters 1γ and 18 are used to convert signals within the control device into operation signals for the fuel adjustment valve drive mechanism γ and the barrier pull vane drive mechanism 10, respectively.

The disadvantage of such conventional systems is that when the superheating margin ΔT of the gas turbine inlet temperature is fixed regardless of the intake air temperature T'1, as shown in FIG. This is because changes in operating conditions are not taken into account.

In other words, when the intake air temperature decreases, the superheat margin ΔT of the gas generator inlet temperature may be large, but if ΔT is held to a constant value, the fuel flow command signal Gf during acceleration
is limited by ΔT, and acceleration performance also deteriorates.

On the other hand, when the intake air temperature rises, the superheating margin ΔT of the gas gene turbine inlet temperature must be reduced.If ΔT is kept constant, the fuel flow command signal Gf becomes excessive during acceleration, and the engine There was a risk of overheating and surging.

The present invention has been made to improve the above-mentioned points.According to the present invention, the superheating margin ΔT of the gas generator inlet temperature was set to a fixed value, but the deviation between the compressor intake air temperature and the design value (T A regulator (5γ) that generates a correction signal Δl for the superheating margin of the gas generator inlet temperature in proportion to I-TID,', and a controller (5γ) that subtracts this correction signal Δl from the reference value Δsum (ΔT=Δsum− ΔTM ) and a comparator (59) that determines the superheating margin ΔT of the gas generator inlet temperature.

The present invention will now be described in detail with reference to a preferred embodiment illustrated in FIG. 5 of the accompanying drawings.

The present invention aims to improve control performance by replacing the superheating margin setting device 30 for the gas generator inlet temperature shown in FIG. 2 with a circuit consisting of elements 51 to 59 shown in FIG. 5.

However, in FIG. 5, peripheral elements are also shown in order to clarify the connection relationship between the circuit of the present invention and other elements.

The measured inlet temperature value T1 of the compressor 1 detected by the temperature detector 51 is compared with the output TID of the reference compressor inlet temperature setter 52 leading to the comparator 53, and a deviation signal TI TID is sent to the gain setter 57. do.

The gain setter 57 generates a correction signal Δ- for the superheating margin of the gas generator turbine inlet temperature in proportion to the magnitude of the deviation TI-TID of the intake air temperature, and sends it to the comparator 59.

The gain setting device 5γ sets ΔC>0 when T1>TID, and ΔTM<0 when T1<TID, T1-
In the case of TID, a signal of ΔTM=0 is output.

The comparator 59 calculates the difference between the output ΔTD of the superheating margin setting device 58 for the reference gas general turbine inlet temperature and the output ΔTM of the gain setting device 5γ, and inputs the superheating margin ΔT for the gas general turbine inlet temperature to the adder 29. =ΔTD−ΔTM is sent.

After all, when the intake air temperature is low, the superheating margin ΔT of the gas generator turbine inlet temperature is increased (line B in Figure 4), and when the intake air temperature is high, the superheating margin ΔT is decreased (line C in Figure 4). become.

In order to make the steady operation line on the compressor map coincide with the maximum efficiency line regardless of the intake air temperature, the gas general turbine inlet temperature target value T- is changed to the corrected gas general turbine rotation speed NfG as shown in Fig. 5. Established against.

That is, the gain setter 54 calculates a correction signal NGC according to the magnitude of the intake air temperature T1 and the reference intake air temperature TID,
Corrected gas general turbine rotation speed NG' obtained by adding this signal NGC to the gas general turbine rotation speed measurement value NG'
The gas gene turbine inlet temperature target value Tt is determined as a function of .

Since the present invention is constructed as described above, the compressor inlet temperature is detected and compared with the reference temperature, and if it is lower than the reference temperature, the superheating margin ΔT of the gas generator turbine inlet temperature is increased. When the temperature is higher than the temperature, by reducing ΔT, acceleration performance can be maintained regardless of changes in intake air temperature, and overheating and surging can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a conventional two-shaft gas turbine, Fig. 2 is a system diagram of its control device, Fig. 3 is a graph showing the relationship between the gas generator rotation speed measurement value NG and the fuel flow rate Gf, and Fig. 4
The figure shows the target gas gene turbine inlet temperature value TF,! - A graph showing the relationship between the gas general turbine inlet temperature and the superheating margin ΔT, FIG. 5 is a system diagram showing the configuration of the present invention, and FIG. 6 is a T
1 is a graph of measured gas generator pin rotation speed versus time showing the transient response when 1 < T ID; 1... Compressor, 2... Gas generator turbine, 3... Power turbine 4...
・Heat exchanger, 5... Combustor, 6... Fuel adjustment valve, γ... Combustion adjustment valve drive mechanism, 8...
... Fuel pump, 9 ... Barrier pull vane, 10 ... Barrier pull vane drive mechanism, 11
...Load, 12...Accelerator pedal,
13...Gas general turbine target rotation speed setting device, 14...Gas general turbine rotation speed detector, 1
5...Power turbine rotation speed detector, 16...
...Gas gene turbine inlet temperature detector, 1γ, 18
...Converter, 19...M barrier pull vane control device, 21, 24° 33.39, 42, 4
4... Comparator, 29, 36, 40...
Adder, 22...Gas gene turbine rotation speed governor, 23...Power turbine target rotation speed setter, 25...Power turbine overspeed protector, 26... ...Function generator (fuel planning line during steady operation), 27...Function generator (maximum fuel line during acceleration), 30...Superheat margin amount of gas gene turbine inlet temperature Setting device, 31...Temperature protector, 32...Phase lead compensation circuit, 34...
... P operation regulator, 35 ... Minimum value selection circuit,
37...Blowout prevention fuel flow rate setting device, 38...
... Maximum value selection circuit, 42 ... - PI operation regulator, 43 ... Barrier pull vane opening adjustment at sudden acceleration/deceleration, 45 ... Barrier pull vane Opening degree determiner, 51...Compressor inlet temperature detector, 5
2...Reference compressor inlet temperature setting device, 53
, 59...Comparator, 54...Gain setter (gas generator rotation speed correction signal), 55...
...Adder, 56...Function generator (gas generator turbine inlet temperature planning line during steady operation), 5γ...
- Gain setting device (correction signal for superheating margin amount of gas general turbine inlet temperature), 58... Superheating margin amount setting device for reference gas general turbine inlet temperature. Nr: Target value of gas gene turbine rotation speed during steady operation, NG
: Measured value of gas general turbine rotation speed, Nr: Target value of power turbine rotation speed during steady operation (overspeed prevention), Nr
P: Measured value of power turbine rotation speed, T7” Target value of gas general turbine inlet temperature during steady operation, T7: Gas general turbine inlet temperature, T7: Measured value of gas general turbine inlet temperature, T2C: Gas general turbine after phase lead compensation Inlet temperature measurement value, T7max: Endurance limit temperature of turbine material,
ΔT: Superheating margin of gas gene turbine inlet temperature, Gf
: Fuel flow rate, Gfs: Planned fuel flow rate during steady operation, ΔGf
: Fuel flow rate change, ΔGfN: Gas general turbine rotation speed governor output, ΔGfp: Power turbine overspeed protector output, ΔGfT: Gas general turbine inlet temperature protector output max" Maximum value for fuel flow rate change (overheat, Prevention of surging), Gfmin
"Fuel flow rate to prevent blowout during sudden deceleration, vG: Barrier pull vane opening (design point standard), VGmax: Upper limit of barrier pull vane opening, VGmin: Lower limit of barrier pull vane opening, VT: Steady Barrier pull vane opening during operation, vN: Barrier pull vane opening during sudden acceleration/deceleration, Δ: Sudden acceleration continuous judgment criterion KN, Ni'N gain, T1: Compressor inlet temperature, T1: Measured compressor inlet temperature, TID : Reference compressor inlet temperature, kc :
Gas general turbine rotational speed correction signal, N2O: Corrected gas general turbine rotational speed, ΔTD: Standard gas-netarbin inlet temperature margin, ΔTM: Correction signal for superheating margin of gas general turbine inlet temperature, K1. 2: Proportional gain.

Claims (1)

[Claims] 1 In a two-shaft gas turbine, when the actual temperature exceeds the limit temperature obtained by adding the superheating margin to the gas general turbine inlet temperature plan set as a function of the gas turbine rotation speed, the fuel is reduced in proportion to the excess. In the circuit for reducing the flow rate, there is provided a controller that generates a correction signal for the superheat margin of the gas generator turbine inlet temperature in proportion to the deviation between the compressor intake air temperature and its design value, and a controller that generates a correction signal for the superheat margin of the gas generator inlet temperature, and uses the correction signal as a reference for the superheat margin. 1. A temperature protector circuit for a two-shaft gas turbine, comprising a comparator that determines a superheat margin amount of a gas gene turbine inlet temperature by subtracting it from a value.