JPS62118010A - Control device for generating plant - Google Patents

Abstract

PURPOSE:To keep heat balance in a plant in normality, by varying the steam pressure setting value as a function of a plant output demand value at the time of plant output alteration, and compensating it by the actual pressure in addition. CONSTITUTION:At an EHC 13a of a turbine, a pressure setting signal is formed by a first function generator as a function of a plant output demand value, while a steam pressure desired value is formed as well by a second function generator 14a. And, a deviation between the steam pressure desired value and the actual pressure signal is inputted into a PID circuit, forming a compensation signal, and the steam pressure setting value is compensated. According to a deviation between this compensated pressure setting value and the actual pressure, governor opening of the turbine is controlled. With this constitution, the steam pressure can be kept to the specified value without offset.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a control device for a power plant using a fast breeder reactor or the like.

[Technical background of the invention and its problems] Figure 2 shows the steam system of a fast breeder reactor power plant. Thereafter, the water is heated by a low-pressure feed water heater 3 , passes through a deaerator 4 , is pressurized by a feed water pump 5 , and is then heated by a high-pressure feed water heater 6 .

The feed water heated by the high-pressure feed water heater 6 is guided to the evaporator 7. After exchanging heat with the liquid metal sodium in the secondary system, it becomes steam and flows into the drain separator 8, then is led to the superheater 9, where it is roughly heated, and then the main steam stop valve 1
0 and is guided to the turbine 1 through the turbine control valve 11.

Upstream of the main steam stop valve 10, a turbine bypass valve 12 is provided.
and the opening degree of the turbine control valve 11.
An electro-hydraulic controller (C) 13 is installed to maintain the mass balance of main steam by dumping excess steam to the condenser 2 through the turbine bypass valve 12 in response to frequency disturbances such as load loss from the power transmission system. The steam pressure is controlled to a predetermined value.

That is, in the steam system as described above, the opening degrees of the turbine bypass valve 12 and the turbine control valve 11 are controlled by the EHCI 3, and the steam system is appropriately operated.

Figure 3 shows the details of El-IC13, and this EH
In 013, the total steam flow rate request signal S1 generated by the steam pressure and the regulator valve flow rate request signal S2 generated by the rotation speed of the turbine 1 are combined, and the turbine steam flow rate (control valve flow rate request signal) + turbine bypass valve steam flow rate = The relationship of total main steam flow rate (total steam flow rate request signal) is always maintained by operating the turbine control valve 11 and turbine bypass valve 12, and the steam pressure is kept stable.

Here, the total steam flow rate request signal S1 and the control valve flow rate request signal S
2 is created as follows.

Total steam flow rate request signal = (Steam pressure car steam pressure setting value) / Pressure regulation rate Meanwhile, in the same way, the regulating valve flow rate request signal = Load setting value + (Rotation speed setting value - Turbine rotation speed) / Speed regulation rate. Here, the steam pressure set value and the pressure adjustment rate are preset constant values.

When changing the plant output in a fast breeder reactor power plant with the above configuration, the reactor output A, 1 Cooperative control is performed in which the primary cooling system flow IB and the secondary main cooling system flow rate C1 are coordinated and changed. Note that in this graph, the vertical axis represents relative values, and the horizontal axis represents elapsed time. At this time, if no disturbance occurs in the power transmission system, the EHC 13 determines the opening degree of the turbine control valve based on the total steam flow rate request signal S1, and controls the steam pressure.

However, the plant output, turbine output, steam flow rate, and turbine control valve opening are approximately proportional to each other. Therefore, with a control device that determines the turbine control valve opening while keeping the steam pressure set value and pressure adjustment rate constant, it will not be possible to maintain the steam pressure at a predetermined value when the plant output is changed, and the overall plant There is a problem that the heat balance is impaired.

[Object of the Invention] The present invention has been made based on the above background art, and it is possible to change the steam pressure even when changing the plant output in a power plant using cooperative control and EHC such as a fast breeder reactor power plant. The present invention aims to provide a control device for a power generation plant that can maintain the heat balance of the power generation plant at a normal value by keeping the amount of energy at a predetermined value without offset.

[Summary of the Invention] That is, the present invention provides a control device for a power generation plant that is installed in a power generation plant that changes the plant output through cooperative control in response to a required plant output value, and that controls steam pressure using EHC. a first function generator that outputs a steam pressure setting signal as a function of the output demand value; a second function generator that outputs a steam pressure target signal as a function of the output demand value of the plant; and the steam pressure target signal. and a correction signal generating device that receives a deviation between the actual steam pressure signal and the actual steam pressure signal and outputs a correction signal, corrects the steam pressure setting signal using the correction signal to make the steam pressure setting value of the EHC, and adjusts the steam pressure The turbine control valve opening degree is controlled according to the amount of deviation between the set value and the actual steam pressure,
By maintaining the steam pressure at a predetermined value without offset, the heat balance of the power plant can be maintained normally.

[Embodiment of the Invention] Hereinafter, details of the present invention will be described by way of an embodiment using the drawings.

FIG. 1 shows an EHC 13a that is necessary in a control device for a power generation plant according to an embodiment of the present invention.This EHC 13a receives an output request signal and uses this as a function to set a steam pressure target signal and a steam pressure setting, respectively. Two function generators 14a and 14b output signals, and the deviation between the steam pressure target signal from the function generator 14a and the actually measured steam pressure measurement signal is input, and a correction signal is output by PID control. The signal generating device 15 is also provided. And this E
The HC 13a is placed in a fast breeder reactor power plant or the like shown in FIG. 2 instead of the EHC shown in FIG. 3.

When changing the plant output in a fast breeder reactor power plant in which this EHC13a is installed, the plant control system is activated and the reactor output is changed according to the plant output request signal as shown in the graph of Figure 4. A, 1st method main cooling system flow rate B, secondary main cooling system flow rate C1, feed water flow rate are coordinated and controlled, and the main steam pressure is controlled as follows in EHC 13a shown in Figure 1. .

That is, in this EHC 13a, the function generator 14b outputs a steam pressure setting signal as a function of the plant output request signal that satisfies the following relationship: steam pressure = steam pressure setting signal value - pressure regulation rate x plant output request value = predetermined value. . The correction signal generating device 15 receives the amount of deviation between the steam pressure target signal outputted from the function generator 14a and the actually measured steam pressure measurement signal, and performs PAD control to eliminate this deviation. Outputs a correction signal. Then, this correction signal and the steam pressure setting signal outputted from the function generator 14b are superimposed to obtain a steam pressure setting value.

Next, the total steam flow rate request signal S3 is calculated from the deviation amount between the steam pressure set value and the actually measured steam pressure and the pressure adjustment rate using the formula shown below.

(Steam pressure car steam pressure setting value) /Pressure regulation rate = total steam flow rate request signal On the other hand, in the same way, the regulating valve flow rate request signal = load setting value + (rotation speed setting value - turbine rotation speed) / speed regulation rate The regulating valve meteor request signal S4 is calculated from the formula, and the turbine steam flow rate (regulating valve flow rate request signal) + turbine bypass valve steam flow ω = total main steam flow rate (total steam flow rate request signal) determines the turbine regulating valve opening, Determine and control the bypass valve opening.

That is, in the power plant control device of this embodiment described above, as a function of the plant output request signal, the following relationship is satisfied: steam pressure = steam pressure setting signal value + pressure adjustment rate × plant output request value = predetermined value. Roughly, the steam pressure setting signal is corrected by PID control based on the deviation between the steam pressure target signal set as a function of the plant output request signal and the actual main steam pressure measurement signal. is set as the steam pressure set value, and the total steam flow rate request signal @S is proportional to the deviation amount between this steam pressure set value and the actual steam pressure.
Since the opening degree of the turbine control valve is controlled by 3, the steam pressure can be maintained at a predetermined value without offset, and a normal heat balance of the entire plant can be maintained.

Although this embodiment describes an example in which the power plant control device of the present invention is applied to a fast breeder reactor power plant, the present invention is not limited to such an example. It goes without saying that it can be used in power generation plants, etc.

[Effects of the Invention] As described above, the power plant control device of the present invention includes a first function generator that outputs a steam pressure setting signal as a function of the plant output request value, and a first function generator that outputs the steam pressure setting signal as a function of the plant output request value. A second function generator that outputs a steam pressure target signal, and a correction signal creation device that receives the deviation between the steam pressure target signal and the actual steam pressure signal and outputs a correction signal, and corrects the steam pressure setting signal. Corrected by signal and EHC
Since the steam pressure setting value is set to , and the turbine adjustment valve opening degree is controlled according to the amount of deviation between this steam pressure setting value and the actual steam pressure, the steam pressure can be maintained at a predetermined value without offset. The heat balance of the power generation plant can be maintained normally.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of an EHC which is a control device for a power plant according to an embodiment of the present invention, Fig. 2 is a piping system diagram showing a fast breeder reactor power plant, and Fig. 3 is a conventional EHC.
A block diagram showing C and FIG. 4 are graphs showing cooperative control. S3・・・・・・・・・・・・・Total steam flow rate request signal S4・・・・・・・・・・・・・・・Adjustment valve flow port request signal 13a・・・・・・・・・・・・・・・EHC14
a, 14b...Function generator 15...Correction signal generation device Applicant Japan Atomic Energy Corporation Applicant Toshiba Corporation Agent Patent attorney Su Yamasa - Figure 2

Claims (2)

[Claims] (1) The EH
A control device for a power plant that controls steam pressure according to C, includes a first function generator that outputs a steam pressure setting signal as a function of the plant output request value, and a steam pressure target output signal that outputs a steam pressure setting signal as a function of the plant output request value. a second function generator that outputs a signal; and a correction signal creation device that receives input of a deviation between the steam pressure target signal and the actual steam pressure signal and outputs a correction signal; The steam pressure set value of the EHC is corrected by the signal, and the turbine adjustment valve opening degree is controlled according to the amount of deviation between the steam pressure set value and the actual steam pressure, and the steam pressure is set to a predetermined value without offset. A control device for a power generation plant, characterized in that: (2) The power generation plant control device according to claim 1, wherein the correction signal generation device performs PID control.