JPS6032002B2 - Turbine control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a turbine for driving a generator.

Generally, in a steam turbine combined with a generator-driving turbine, for example, a boiling water nuclear reactor as a boiler for steam generation, a turbine control device normally controls pressure and does not perform speed/load control.

In such plants, when the generator and load circuit are disconnected or disconnected from the power grid and the steam turbine attempts to continue operating independently, it temporarily shifts to speed/load control, but then the pressure increases again. Attempting to take control
A problem arises in that speed/load control of the turbine is no longer performed. As a result, the turbine cannot be maintained at the rated speed. Therefore, a means is required to transition from pressure control to speed/load control in some way. Hereinafter, the functions and drawbacks of the follower device will be explained with reference to the accompanying drawings.

Figure 1 is a diagram showing the air supply system of a boiling water nuclear turbine using a nuclear reactor as a boiler for steam generation.
The steam coming out from the main steam stop valve 103 and the steam control valve 104
and flows into the high pressure turbine 107.

The steam exiting this high pressure turbine 107 is sent to a moisture separator 105.
a, 105b, intermediate stop valves 106a to 106f, and flow into low pressure turbines 108a to 108c, and the respective exhaust gases are guided to a condenser 110. The water condensed by the water softener 110 is returned to the reactor by the reactor feed water pump 111. On the other hand, if the amount of steam generated from the nuclear reactor is larger than the steam flow rate required by the turbine, the steam is directly flowed to the condenser 110 through the turbine bypass valve 102. Figure 2 is a diagram showing the configuration of a turbine control device applied to a boiling water reactor. In the figure, 1 indicates the speed signal obtained by detecting the turbine rotation speed with an adder and the speed that sets the turbine rotation speed. Extract the deviation from the set signal.

2 is an amplifier, and 3 is an adder to which the output of the amplifier 2 and a generator load setting signal are applied, and 1 to 3 constitute a speed/load control circuit.

4 is an adder which detects the pressure of steam generated from the nuclear reactor and is supplied with a false pressure signal and a pressure setting signal for setting the pressure of steam generated from the nuclear reactor.

5 is an amplifier, and these 4 and 5 constitute a pressure control circuit.

7 is a low value priority circuit which compares the output signals of the speed/load control circuit and the pressure control circuit, allows only the low value signal to pass with priority, and opens and closes the steam control valve based on this pass signal.

7 and 8 are adders, 9 is a bias setting device that generates a signal at a constant ratio to the output signal of the pressure control circuit, and 10 is a limiter that generates a signal suitable for the object to be controlled.

Also, the symbols A, B, C to N on the lines connecting each component
is for establishing the action. In Figure 2,
Turbine rotational speed signal A is converted into speed setting signal B by adder 1.
The deviation signal C is amplified by an amplifier 2 having a gain commensurate with the regulation rate, and the output signal D and the load setting signal E are added by an adder 3. The steam flow rate signal F represents the required steam flow rate.

On the other hand, the reactor pressure signal G is compared with the pressure setting signal by an adder 4, and the deviation signal J is amplified by an amplifier 5, which also has a gain commensurate with the adjustment rate, and is used to generate steam representing the steam flow rate generated from the reactor. A flow rate signal K is obtained.

The respective signals F, K thus produced by the two different detectors, namely the speed/load control circuit and the pressure control circuit, are compared by a low value priority circuit 6, and only the low value signal is passed. Then, the steam control valve flow rate signal L is obtained.

Further, in the adder 7, the regulator valve flow rate signal L is subtracted from the steam flow rate signal generated from the nuclear reactor, that is, the output K of the pressure control circuit, to obtain the turbine bypass valve flow rate signal M.

Further, the adder 8 subtracts K from F, and then the signal generated from the bias setting device 9, that is, 10 of the signal K.
The signal corresponding to [%] is subtracted, and the obtained signal becomes the signal N to be applied to the reactor control device via the limiter 10. In the turbine control device configured as described above, when the steam flow rate generated from the reactor is larger than the steam flow rate required by the turbine, for example, when the booster load is 80 [%] and the reactor output is 90 [%], When the steam flow rate signal F required by the turbine is 80%, the steam flow rate signal K generated from the reactor is 90%, and the signal to open and close the steam control valve is sent through the low value priority circuit 6. L to 80 [%]
At the same time, the signal K of the steam flow rate generated from the nuclear reactor and the steam control valve flow rate signal L are compared and calculated by an adder 7, and based on the output of the adder 7, 1 from the turbine bypass valve is calculated.
This results in 0% of steam being released.

In such a situation, the speed/load control circuit signal takes priority over the steam control valve and the turbine bypass valve, and changes in the turbine speed signal A or load setting signal E are not applied to the steam control valve. Acting speed/load control.
On the other hand, if the steam flow rate required by the turbine is greater than the steam flow rate generated from the reactor, for example, if the generator load requirement is 90 [%] and the reactor output is 80 [%], then F=
90 [%], K=80 [%], the output of the low value priority circuit 6 becomes the steam control valve flow rate signal L=80 [%], and the signal of the pressure control circuit is given priority to the steam control valve.

In other words, "Since the steam flow rate is proportional to the steam pressure, the steam control valve is essentially a pressure control controlled by the steam pressure generated from the reactor. During this pressure control, K =
Due to L, the output of the adder 7, ie, the turbine bypass valve signal M, is zero and this valve is closed.

Operating the turbine with the bypass valve open all the time involves a loss of energy, and the pressure of the steam control valve is normally controlled in this way.

In the end, there is a difference between the signal K of the steam flow rate generated from the reactor and the signal F of the steam flow rate required by the turbine, F-K>10 [
%], a signal to increase the output is sent to the reactor, and in a state where F-K<10[%], a signal to reduce the output is sent to the reactor.

In a turbine control device that operates as described above,
When the turbine generator is unloaded or switched to independent operation, the turbine speed increases, so that a relationship of F-K<10% is established between the signal F and the signal K, Once it moves to speed/load control, it returns to F-K>
10 [%] and pressure control continues, so it has the disadvantage that it is impossible to control the load and rotational speed of the turbine generator.

Figure 3 shows the load disconnection time T that interrupts the load circuit of the generator.
This shows the process in which speed/load control is carried out at time T3, and then shifts to pressure control at time T3. The required steam flow rate signal drops rapidly and the steam control valve is fully closed. At the same time, the turbine bypass valve is opened, and the signal N given to the reactor control device acts as a power reduction. As the reactor power decreases in this manner, the signal K representing the flow rate of steam generated from the reactor gradually decreases. On the other hand, as the steam control valve is fully closed, the turbine continues to decelerate due to windage etc., and the steam flow rate signal F required by the turbine gradually rises, and there is a gap between F=K and the steam flow rate signal K generated from the reactor. At the time UL, the steam regulating valve is opened by the regulating valve flow rate signal L, some steam is sent to the turbine, and at the same time, the turbine bypass valve is closed. moreover,
At time T3 when F-K=10 [%], the signal N for reducing the output to the reactor becomes zero, and the pressure is controlled thereafter. In the end, by suppressing the output generated from the reactor to 10% lower than the steam flow rate signal required by the turbine, fluctuations in turbine speed due to load fluctuations are blocked by the low value priority circuit, and steam control is reduced. This has the disadvantage that the valve cannot be adjusted.

SUMMARY OF THE INVENTION An object of the present invention has been made to eliminate the above-mentioned drawbacks, and it is an object of the present invention to provide a turbine control device that enables speed/load control of a turbine generator when the load is on or off, or when the turbine generator is in standalone operation. .

An embodiment of the present invention will be described below with reference to the accompanying drawings.
FIG. 4 is a diagram showing the configuration of the turbine control device of the present invention,
A second bias setting device 11 having a large absolute value and an opposite sign is added to the bias setting device constituting the conventional device shown in FIG. It is configured.

For example, set the setting value of the second bias setting device to 100Q [%]
By activating the relay 12 when the load is disconnected or during individual operation, a signal of 100 Q [%] is further added to the adder 8, and the bias of both bias setters is 10 [%].
%] are canceled out and the signal N is generated until the signal K of the steam flow rate generated from the reactor G is Q [%] more than the signal F of the steam flow rate required by the turbine, contrary to the pressure control time, Moreover, this signal N acts as an output booster.

As a result, Q [%] of steam is released from the turbine bypass valve, speed/load control is performed on the steam control valve, and the turbine speed is maintained at a constant value. FIG. 5 shows changes in each signal of the turbine control device according to the present invention corresponding to FIG. 3. From time T to T3, the changes follow the same tendency as explained in FIG. Hereinafter, the turbine bypass valve flow signal M has a value of Q [%] and is connected to the bypass valve, and the steam control valve flow signal L is a signal of the speed/load control circuit, and the turbine is maintained at the rated rotational speed. In order to
Turbine speed signal A takes a constant value.

Due to this speed/load control, some of the steam generated from the reactor is wasted depending on the turbine bypass valve, but compared to the turbine pressure control time, the speed/load control is short-term. This puts emphasis on maintaining the rated speed of the turbine.

As is clear from the above explanation, in a turbine control device that normally performs pressure control, it is possible to continue speed/load control when the load of the generator is off, or when the generator is in standalone operation. When speed load control is particularly required, the reverse bias setting device of the present invention can be activated.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a turbine air supply system, FIG. 2 is a diagram showing the configuration of a conventional turbine control device, and FIG. 3 is a diagram for explaining the operation of the conventional turbine control device shown in FIG. 2. ,
FIG. 4 is a diagram showing the configuration of the turbine control device of the present invention, and FIG. 5 is a diagram for explaining the operation of the turbine control device according to the present invention shown in FIG. 4. 1, 3, 4, 7, 8... Adder, 2, 5...
・Amplifier, 6...Low value priority circuit "9...
Bias setting device, 10...' limiter, 101...
・Nuclear reactor, 102...Turbine bypass valve, 103
...Main steam stop valve, 104...Steam control valve 105a, 105b...Moisture separator, 10
6a-106f...Intermediate stop valve, 107...
- High pressure turbine, 108a to 108c...Low pressure turbine, 109... Generator, 110... Condenser, 111... Nuclear reactor feed water pump. Ta 2 Prison Hair 2 Zu Ta 8 Prison Hair 4- Zu Ta 5 Prison

Claims (1)

[Claims] 1. A speed signal obtained by detecting the rotational speed of the turbine, a speed setting signal for setting the rotational speed of the turbine, and a load specification signal for the generator are given, and a speed at which the steam flow rate signal required by the turbine is output. / A load control circuit, a pressure signal obtained by detecting the pressure of steam generated from the boiler, and a pressure setting signal for setting the pressure of the steam generated from the boiler are provided, and a steam flow rate signal generated from the boiler is provided. The pressure control circuit to be output is compared with the output signals of the speed/load control circuit and the pressure control circuit, and only the low value signal is passed with priority, and this passing signal is used to open and close the steam control valve, giving priority to the low value. a first adder that subtracts the output signal of the low value priority circuit from the output signal of the pressure control circuit and opens and closes the turbine bypass valve based on the difference signal; a bias setting device that generates a signal at a constant rate; subtracting the output signal of the pressure control circuit from the output signal of the speed/load control circuit; and further subtracting the output signal of the bias setting device; A reverse bias setting device that outputs a signal having a large absolute value and an opposite sign to the signal generated from the bias setting device in the turbine control device configured with a second adder that is applied to the boiler control device. is added, and the signal of this reverse bias setter is
1. A turbine control device characterized in that the speed/load control can be continued when the turbine generator is under load or when the turbine generator is in standalone operation.