JPS6133977B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rapid deceleration control device for a two-shaft gas turbine with a heat exchanger, which is a type of regenerative gas turbine.

A conventional two-shaft gas turbine of this type and its control device have a configuration shown in FIGS. 1a and 1b. As is clear from these figures, the compressor 1 is coaxial with a gas generator turbine (hereinafter abbreviated as gas generator) 2, and the power turbine 3 is coaxial with a load 11. Atmospheric air is compressed by a compressor 1, passes through a heat exchanger 4, and reaches a combustor 5. From fuel pump 8,
Fuel adjustment valve 6 controlled by fuel adjustment valve drive mechanism 7
The fuel passing through the combustor 5 is combusted by the aforementioned air. Combustion gas is gas genera 2
The air enters the air, performs work in the power turbine 3 via the variable vanes 9, and is discharged as exhaust gas through the heat exchanger 4. The device that controls this system includes a fuel/variable vane control circuit 20 as shown in FIG. The intake air temperature detector 17 is input to the control signal calculation circuit 22, and the output of the gas general rotation speed setting device 13 set by the accelerator pedal 12 is compared with the gas general rotation speed detector 14 by a comparator 21, and the output is also It is used as an input to the control signal calculation circuit 22. The fuel flow rate command signal G _f from the control signal calculation circuit 22 is sent to the fuel adjustment valve drive mechanism 7 via the converter 18 .
Further, the variable vane opening command signal V _G which is the output of the control signal calculation circuit 22 is transmitted to the converter 19
It is sent to the variable vane drive mechanism 10 via.

The meanings of the symbols in FIGS. 1a and 1b are as follows.

N _G 〓: Gas general rotation speed set value during steady operation N _G : Gas general rotation speed measurement value N _P : Power turbine rotation speed measurement value T ₇ : Gas general inlet gas temperature T ₇ : Gas general inlet gas temperature measurement value T ₇ 〓: Steady state Gas general inlet temperature target value during operation T ₁ : Compressor intake air temperature T ₁ : Compressor intake air temperature measured value T ₅ : Combustor inlet temperature, T _c : Heat exchanger core temperature, V _G : Variable vane opening command signal (design point (change from the opening) G _f :Fuel flow rate command signal The circuit shown in Figure 1b is suitable for vehicle gas turbines and is equipped with the following functions.

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

(b) Improving sudden acceleration/deceleration performance.

(c) Preventing materials from overheating due to excessive fuel injection, and preventing overspeeding of rotating parts due to power imbalance.

Now, in such a conventional device, when there is a sudden deceleration, the accelerator pedal 12 is released and the gas gener- ation rotation speed set value N _G 〓 is suddenly decreased, but the control device 20 decreases the fuel flow rate in accordance with the sudden decrease in N _G 〓. Send out a signal G _f . The rotation speed of the gas generator 2 is determined by the energy of the combustion gas input to the gas generator (i.e., the _gas temperature at the gas generator inlet, T ₇ , etc. ₎ . It is desirable to be able to rapidly reduce Due to fuel loss during sudden deceleration, T ₇ will descend quickly up to a certain level. However, after that, the core temperature T _c of the heat exchanger does not drop rapidly, so the fall of T ₇ becomes slow (see Figure 3d). As a result, even if G _f is maintained at the lowest fuel line, the energy of the combustion gas decreases only gradually, resulting in a delay in deceleration of N _G. Therefore, when sudden deceleration is requested,
The drawback was that it could not provide sufficient deceleration performance.

The present invention has been made to solve this drawback, and is designed to quickly lower the core temperature _Tc of the heat exchanger,
The purpose is to quickly make the gas generator rotational speed N _G follow its set value N _G 〓.

That is, according to the present invention, a bypass pipe and a control valve are provided between the air discharge port of the compressor and the low-pressure side inlet of the heat exchanger, and the opening degree of the control valve is adjusted according to the degree of sudden deceleration (deviation of the gas generator rotation speed). N _G 〓― _NG )
The core temperature of the heat exchanger can be lowered quickly by adjusting the temperature accordingly and guiding part of the air discharged from the compressor to the low-pressure side inlet of the heat exchanger during sudden deceleration. do. As a result, deceleration performance is improved. Note that this control valve is closed during steady operation and during acceleration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to preferred embodiments of the present invention illustrated in FIG. 2a of the accompanying drawings.

In FIGS. 2a and 2b, the repeated explanation of the parts common to FIGS. 1a and 1b will be omitted.

In the illustrated embodiment, the bypass pipe 56a is branched midway from the outlet of the compressor 1 to the inlet main pipe 57 of the heat exchanger 4, and a bypass valve 55,
It is communicated with a main pipe 58 leading from the power turbine 3 to the heat exchanger 4 via a bypass pipe 56b. One input N _G =-N _G of the control signal calculation circuit 22 in FIG.
Signals from the delay circuit 52 and converter 53 are input to the bypass valve opening adjustment mechanism 54, which controls the bypass valve 55.

The newly used symbols in FIGS. 2a and 2b are as follows.

T ₂ : Compressor outlet temperature, T ₅ : Combustor inlet temperature T ₁₀ : Power turbine outlet temperature T ₁₁ : Heat exchanger low pressure side inlet temperature P ₂ : Compressor outlet pressure P ₁₁ : Heat exchanger low pressure side inlet pressure Here, The input/output relationship of the regulator 51 is set as shown in the graph shown in FIG. 2c, but the sudden deceleration determination criterion (Δ) and the gain _KBV of the proportional adjustment section are determined appropriately. Furthermore, the fluid resistance ratio between the main line 57 and the bypass line 56 when the valve opening degree is 100% is determined appropriately so as to maintain the air-fuel ratio for maintaining the rotation of the gas generator shaft.

The operation of the control device of the present invention will be described below.

The regulator 51 adjusts the deviation (N _G 〓
-N _G ) and the sudden deceleration judgment criterion (-Δ; Δ> ₀ ).
〓-N _G |-Δ) The opening degree of the bypass valve 55 is commanded. The delay circuit 52 is for appropriately shifting the operation timing of the bypass valve 55 from the timing of the rapid deceleration command. Also, converter 5
3 is for converting the output signal of the delay circuit 52 into an operation signal for the bypass valve opening adjustment mechanism 54. In addition, when N _G 〓-N _G >-Δ, the controller 5
The output of 1 is zero.

Now, consider a situation where the gas turbine is operated steadily (|N _G 〓−N〓|<Δ) and the accelerator pedal 12 is suddenly released due to sudden deceleration. That is, the setting device 13 controls the accelerator pedal 1
2, so the output of the setting device 13 N _G 〓
will decrease in steps. As a result,
The deviation of the gas general rotation speed (NG _〓 - _NG ) is NG _〓
Since -N _G <-Δ, the regulator 51 outputs a signal instructing the opening degree of the bypass valve 55 according to the degree of sudden deceleration (|N _G 〓-N _G |-Δ). This signal is sent to the delay circuit 52 and delayed by an appropriate amount of time, and then converted by the converter 53 into an operation signal for the bypass valve opening adjustment mechanism 54. The adjustment mechanism 54 opens the bypass valve 55 and opens the bypass line 5.
6-a and 56-b are connected. The reason why the delay circuit was provided is that at the beginning of deceleration, the outlet temperature _T2 of compressor 1 is high and a sufficient cooling effect cannot be obtained, and a certain degree of deceleration effect can be obtained when the fuel suddenly decreases. .

As a result, a part of the compressed air (temperature T ₂ ) discharged from the compressor 1 is diverted from the main pipe 57 to the bypass pipe 56, guided to the low-pressure side inlet of the heat exchanger 4, and discharged from the power turbine. Gas (temperature)
T ₁₀ ), the core temperature T _c can be quickly lowered as shown in Figure 3c (T _{10 )} .
> _T2 ).

On the other hand, the control signal calculation circuit 22 outputs a signal G _f to reduce the fuel flow rate at the same time as the sudden deceleration command, and together with the decrease in the core temperature due to the air flowing in from the bypass pipe, deceleration can be performed more quickly than in the conventional example. As the gas generator rotational speed decreases, the output of the regulator 51 decreases along the setting line of the regulator 51, so the flow rate of compressed air diverted to the low-pressure side inlet of the heat exchanger 4 via the bypass pipe 56 is It decreases smoothly and can continuously shift to control operation during steady operation (|N _G 〓− _NG | <Δ).

[Brief explanation of the drawing]

FIG. 1a is a system diagram of a conventional two-shaft gas turbine with a heat exchanger, FIG. 1b is a system diagram of its control device, and FIG. 2a is a system diagram of a two-shaft gas turbine with a heat exchanger according to the present invention. Fig. 2b is a system diagram of the control device, Fig. 2c is a graph showing the characteristics of the bypass valve opening degree regulator, and Fig. 3 is a graph of each parameter. 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 gas temperature detector,
17...Compressor intake air temperature detector, 18,1
9...Converter, 20...Fuel/variable vane control device, 21...Comparator, 22...Control signal calculation circuit, 51...Bypass valve opening degree regulator, 5
2...Delay circuit, 53...Converter, 54...
Bypass valve opening adjustment mechanism, 55... Bypass valve,
56 (a, b)... Bypass pipe line, 57, 58...
...Main pipe.

Claims (1)

[Claims] 1. A bypass pipe with a regulating valve is provided between the air discharge port of the compressor of the two-shaft gas turbine with a heat exchanger and the low-pressure side inlet of the heat exchanger, and the bypass pipe is adjusted according to the degree of sudden deceleration during sudden deceleration. A circuit is installed to output a signal that commands the opening of the control valve in the road.
Depending on the degree of sudden deceleration, part of the air discharged from the compressor is guided to the low-pressure side inlet of the heat exchanger to lower the temperature at the low-pressure side inlet of the heat exchanger, thereby making it possible to quickly decelerate. This is a rapid deceleration control device for two-shaft gas turbines.