JPS5960601A - Device for controlling water supply - Google Patents

Abstract

PURPOSE:To obtain a device which can quickly and stably throttle the flow rate of a main water supply at the time of accident of the electricity transmitting and distributing system by providing a means or the like which directly inputs the variation of the main steam pressure of a boiler and drives a feed water pump driving device. CONSTITUTION:A function generator which directly inputs the variation of the main steam pressure of a boiler and outputs a driving signal of a feed water pump driving device and others are provided. At ordinary times, for example, a water supply command signal 20 sent from a device 15 for totally controlling a plant is inputted into a turbine 2 and feed water pump driving device, such as motor, etc., through a PI operator 24 and an operator 28 and the feeding flow rate of a feed water pump 1a is controlled. When the electricity transmitting and distributing system is in trouble, etc., the connection between the PI operator 24 and operator 28 is released and the function generator 32 and the operator 28 are connected to each other, by inputting an FCB generate signal into a switching device 33. Then, the function generator 32 directly inputs the main steam pressure signal 34 of the boiler and outputs a command signal 35 for the number of revolutions of the feed water pump, by which an appropriated feeding water flow rate is discharged at the time of single operation in the station.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a water condensation control device for controlling a feed water pump in a power generation plant.

[Technical background of the invention]

FIG. 1 is a diagram showing the configuration of a general power generation plant.

In other words, 1! L is a water supply pump driven by the turbine 2, and 1b is a water supply pump driven by the electric motor 3. The water supply pumps 1a and 1b each suck condensate from the condenser 4 and supply water to the boiler 5. The fuel stored in the fuel tank 6 is fed into the griller 5 by the fuel bomb f2, and the air for combustion is fed by the blower fan 8, so that the fuel is combusted and the supplied water is released. Convert to steam. What about the combustion exhaust gas generated at that time? ! It is ejected from the rear end of ε, etc. The steam currently produced in the boiler 5 is reduced to main steam by the main steam amount control valve 9, and after rotating the main steam turbine 1o, it is transferred to the condenser 4 with cold water and heat circulated by the circulating water pump flll. The water is exchanged and cooled, and the water is recycled and used to feed the water supply pumps 1a and 1b. The rotation of the main steam turbine 10 is transmitted to the generator iz to generate electricity. A part of the electricity generated in the power generating unit 12 is supplied to the power station as in-house power, and the rest is not sent to the power transmission and distribution line 13 as military power.

In addition, a main breaker 14 is interposed between the 10th floor station @@12 and the power transmission and distribution system 13, and the power transmission and distribution system 13
i, -1#, is configured to be opened when there is no need to stop power transmission due to an accident or the like.

Orai, Mae Jji no 7! The water supply bong 7'18 in the power generation ground generally has its water supply flow rate controlled by a picture book control system shown in a block diagram as shown in FIG. That is, in the plant integrated wholesale value 1 device d15, a deviation signal 18 obtained by subtracting the main water supply flow rate signal 17, which is the sum of the water supply flow rates of each water supply pump 1a and 1b in the power generation plant, from the water supply demand signal 16 is inputted to the PI calculator 19. , outputs the water supply command signal 2o. Water supply control device 21
When the water supply command signal 2o is input, the controller performs the following calculation to control the water supply flow rate of the water supply pump 1a. That is, from the water supply command signal 20 to the water supply bottle 7011L.
The deviation signal 23 obtained by subtracting the water supply flow rate signal 22 is input to the PI calculator 24, and the rotation speed command signal 25 of the water supply pump 1a is
Output. Next, a deviation signal 27 obtained by subtracting the actual rotational speed signal 26 of the water supply pump 1a from the rotational speed command signal 25 of the water supply bong 701a is inputted to the calculator 28, and a steam amount control valve drive command signal (hereinafter referred to as "valve drive command signal (abbreviated as J) outputs 29.

This valve drive command signal 29 controls the steam amount adjustment valve 31 in the water supply mechanism 3o, and adjusts the water supply flow rate of the water supply pump 1a. Note that when controlling the water supply bottle f1b driven by the electric motor 3, a predetermined signal for controlling the armature voltage and the like of the electric motor is outputted from the above-mentioned arithmetic unit 28.

In a general commercial thermal power generation ground, two water supply pumps Ia driven by a turbine 2 and one or two water supply pumps 1b driven by an electric motor 3 are installed.
A water supply control device 21 configured as described above is attached to each W.

Depending on the load on the power generation ground, one or two of the water supply pumps 1a and 1b are operated, and the water supply control device 21 attached to each of these pumps receives output from the plant integrated control device a15. The water supply command signal 20 is configured to follow the water supply command signal 20. In addition, the main water supply flow rate signal 17, which is the sum of the water supply flow rates of each of the water supply pumps 1a and 1b, is fed back to the plant integrated control device 15, so that each of the water supply pumps 1a and 1b
Mutual cooperation is being taken.

By the way, if it becomes necessary to stop power transmission due to an accident in the power transmission and distribution system 13, the main circuit breaker 14 is opened and the power transmission and distribution system 13 is disconnected, and only the power consumed within the power plant is covered. It is necessary to switch to isolated operation within the station and wait until the power transmission and distribution system 13 described below is restored. Therefore, the power plant must perform so-called PCB to rapidly throttle the fuel supply to the boiler 5, and must also rapidly throttle the main water supply flow rate to the boiler 5.

Conventionally, the main water supply flow rate control to the zlP ira 5 at the time of transition to the in-house independent operation is performed by inputting the water supply command signal 2° from the ground general control device 15 to the water supply control device 21 having the above-described configuration, as in normal operation. It was carried out by the

[Problems with background technology]

As mentioned above, if it becomes necessary to stop power transmission due to an accident in the power transmission system 13, etc., the conventional water supply control device f,
? 1, because it operates in response to fairly slow load changes during normal operation, it cannot respond to sudden changes such as controlling to the same one bag as the PCB, and therefore the PCB
There is a problem in that there is a slight time delay in controlling the main water supply flow rate to the boiler 5, which is carried out at the same time as B, and as a result, the durability of the power plant is degraded. Also, the recent release “NU
Since the main steam pressure to boiler 5 is adjusted by variable pressure operation at the plant, depending on the state of the main steam pressure when a PCB occurs, the conventional water supply control device 2 may be activated and then the system may be operated at the discretion of a more experienced operator. This posed a problem in facility management, as it required manual intervention to correct the main water supply flow rate.

[Purpose of the invention]

The purpose of the present invention is to eliminate the above-mentioned problems and to
To provide a water supply control device that can quickly and stably reduce the main water supply flow rate to the amount required for isolated operation within a power plant, without being affected by the state of the main steam pressure of a power plant, at the time of occurrence. There is a thing.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized by the following configuration. That is, the present invention provides a water supply control device that converts a water supply command signal sent from a plant general control device into a drive command signal for a water supply pump drive device such as a turbine or an electric motor through a PI computing unit and a computing unit. A function generator is provided to output a drive signal for the feedwater pump drive device by directly inputting changes in the main steam pressure of the boiler instead of the water supply command signal from the control device, and the above P
The output terminal of the I computing unit and the output side terminal of the function generator are automatically switched by a switching device, and either one is connected to the computing unit. Therefore, normally, a water supply command signal from the plant integrated control device is input, and when the power generation plant is switched to on-site isolated operation due to an accident in the power transmission and distribution system, the water supply flow rate is then adjusted to the appropriate value for the above-mentioned on-site isolated operation. Until it is narrowed down, the switching device is automatically switched to the function generator side, and the value of the main steam pressure of the boiler is directly controlled by the function generator to discharge an appropriate flow rate of feed water in the above-mentioned independent operation. is converted into a water supply pump rotation speed command signal. A deviation signal obtained by subtracting the actual rotational speed signal of the water supply pump from the water supply pump rotational speed command signal is input to the arithmetic unit to output a drive signal for the water supply input drive device R. .

[Embodiments of the invention]

FIG. 3 and FIG. 4 are diagrams for explaining one embodiment of the present invention. Note that the same parts as in FIGS. 1 and 2 shown above are given the same reference numerals, and a detailed explanation of those parts will be omitted.

In Fig. 3, 32 is a function generator, which is automatically connected to the computing unit 28 side by a switching device 33 at the start of isolated operation in the station, that is, at the occurrence of a so-called PCB that rapidly reduces the supply of fuel to the generator 5. The configuration is as follows. Note that the connection between the function generator 32 and the computing unit 28 side is opened after the water supply flow rate has been narrowed down to an appropriate value for the above-mentioned in-house independent operation, and the PI computing unit 24 and the computing unit 28 side are connected again. Ru.

The function generator 32 includes a main steam pressure signal 3 of the boiler 5.
4 and outputs a water supply pump rotation speed command signal 35 that discharges an appropriate water supply flow rate in isolated operation within the station is given in advance.

FIG. 4 is a diagram showing an example of the above function. That is, when the main steam pressure cuff 2, 3 [ATG], the water supply pump rotation speed is 2700 (rpm), the main steam pressure is 18θ, 3
When [ATG:], water supply pump rotation speed s 9 o O
[rpm:], main steam pressure 366, 7 [ATG
] is a function shown by a curve such that the water supply pump rotational speed is controlled to 5500 Crpm].

The switching device 33 operates to connect the function generator 32 and the arithmetic unit 28 side when the PCB generation signal is input. Further, when the water supply flow rate is subsequently narrowed down to an appropriate value for in-house independent operation, the water supply flow rate signal is detected, the connection between the function generator 32 and the calculator 28 is released, and the PI calculator 24 It operates as if connected to the computing unit 28 side.

Next, the operation of this embodiment having the above configuration will be explained.

That is, normally, the water supply command signal 2o sent from the plant integrated control unit w15 is sent to the PI computing unit 24 and the computing unit 2.
By controlling the water supply pump driving device such as the turbine 2 and the electric motor 3 through the water supply pump f i h (7b
) controls the water supply flow rate. ``When the plant is switched to in-plant isolated operation due to an accident in the electric power transmission and distribution system 13, the PCB generation signal is input to the switching device 33, and the P■ calculation unit 24 and calculation unit 28 side connection is opened, and the function generator 32 is connected to the arithmetic unit 28 side.Then, the function generator 32 directly inputs the main steam pressure signal 34 of the boiler 5, and ensures proper water supply in isolated operation within the station. A water supply pump rotation speed command signal 35 is output that causes a flow rate to be discharged.Then, from this water supply pump rotation speed command signal 35, the actual rotation speed 1g of the water supply pump 1a (1b) is determined.
By inputting the deviation signal 36 obtained by reducing the signal 26' to the disintegrator 28, the feed water flow ↑.

In this embodiment, as described above, the feed water flow rate of the water supply cylinder 7'1a (1b) is directly controlled by the main steam pressure signal 34 of the boiler 5, so that the feed water flow rate is narrowed down at the same time as the PCB, and the PCB is generated. Appropriate water supply control can be performed regardless of the state of the main steam pressure at the time. After that, when the water supply flow rate is narrowed down to an appropriate value for in-house independent operation, the switching device 33 detects the water supply flow rate signal, the connection between the function generator 32 and the computing unit 28 is released, and the PI calculation is performed again. The unit 24 and the arithmetic operation 'a28 side are connected. Due to the above effects, at the start of isolated operation in the station, that is, P
When CB occurs, the water supply flow rate can be quickly narrowed down.

Note that the present invention is not limited to the above-mentioned embodiment. For example, the power function given to the function generator 32 is the fourth
It is not limited to what is shown in the figure, but should be determined experimentally since it varies depending on the rating of the equipment such as the water bottle fl a (1b). Furthermore, the switching device 33 may be controlled not based on the PCB generation signal and the water supply flow rate signal, but also on other signals. Further, when main steam pressure control of the y+ queiler 5 is performed in the plant general control device #15, the main steam pressure set value signal of the plant general control device 15 may be input to the function generator 32. In addition, main steam pressure signals are input from a plurality of main steam pressure sensors, and a main steam pressure set value signal from the plant integrated control device 15 is also input, and the average value of two approximate signals is used to generate a function. It may also be input into the device 32. In this case, there is an effect that even if any of the signals is an abnormal value, appropriate water supply control can be performed and reliability is improved.

〔Effect of the invention〕

According to the present invention, when the power generation plant is switched to in-house isolated operation due to power transmission arrangement M, grid failure, etc., the switching device is automatically switched to the circuit on the function generation side, and the main steam of the boiler is Since the feedwater flow of the water supply ponder is controlled by directly inputting the pressure value, the main feedwater flow rate can be quickly and stably adjusted to independent operation within the plant without being affected by the main steam pressure of the power plant. This has the effect of automatically narrowing down to the required amount.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the configuration of a general power generation plant, Fig. 2 is a schematic block diagram showing an example of conventional water supply control, and Fig. 3 is a block diagram showing the configuration of an embodiment of the present invention. 4
The figure is a diagram showing an example of a function given to the function generator of the same embodiment. 1a and 1b...water supply pump, 2...turbine,
3...Electric motor, 4...Condenser, 5...Boiler, 6
...Fuel tank, 7.Fuel pump, 8.Blower fan, 9.Main steam amount control valve, 10.Main steam turbine, 1..Circulating water pump, 12.. ·Generator,
13...Power transmission and distribution system, 14...Main breaker, 1
5... Plant general control device, 16... Water supply demand signal, 17... Main water supply flow rate signal, 18... Deviation signal, 19... PI calculator, 20... Water supply command signal,
21... Water supply control device jM, 22... Water supply flow rate signal, 23... Deviation signal, 24... PI calculator, 25...
... Rotation speed command signal, 26... Actual rotation speed signal, 27.
... Deviation signal, 28... Calculator, 29... Steam amount control valve drive command signal, 3o... Water supply 4: A structure, 31...
- Steam amount adjustment valve, 32... Function generator, 33... Switching device, 34... Raw fish air pressure signal 135... Rotation speed command signal, 36... Deviation signal.

Claims (1)

[Claims] Plan) A PI calculator that converts the deviation signal obtained by reducing the water supply flow rate signal τR from the water supply command signal sent from the M integrated control device into the first water supply pump rotation speed command signal, and the power generation brand is operated in a single station. a function generator that inputs the value of the main steam pressure of the boiler and converts it into a second feed water pump rotation speed command signal for discharging an appropriate feed water flow rate in the station independent operation; In addition, 1: Subtract the actual rotation speed signal of the feed-1 and pump from the second water supply pump rotation @command signal, and convert the deviation signal to the drive command signal of the water supply pump drive p+ device. Normally, the water supply pump rotation speed command signal for the 1st water supply pump output from the PI calculator is sent to the above calculation μ≦. Hayabusa driving 2
Until the value is narrowed down to an appropriate value, the second water supply output from the function generator is used. A water supply control device comprising a switching device that automatically switches a circuit to send a pump rotation speed command signal to the arithmetic unit.