JPS63176605A - Warming controller - Google Patents

Abstract

PURPOSE:To shorten a span of warming time, by detecting a process throughout for monitoring steam pressure and constraint conditions of warming object apparatuses, while calculating the manipulated variable of a warming valve independently, and selecting the minimum. CONSTITUTION:Each signal out of a pressure sensor 8, a metal inner surface temperature sensor 9, a metal outer surface temperature sensor 10, etc., installed in a governor 4 is inputted into a warming controller 20. And, each control signal is operated from these signals at a pressure control signal operational part 23, a temperature variation control signal operational part and a temperature difference control signal operational part 32, and these signals are set down to a low value signal (m) via a low value preference part 24, transmitting it to a warming valve opening setter 16. With this constitution, a warming valve is controlled in the state that satisfied various constraint conditions all the time, thus a span of warming time is reducible.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a warming control device for turbine-related equipment.

(Conventional technology) For example, thermal power plants, nuclear power plants, etc.
In a power generation plant using a steam turbine, when the plant is started up, so-called turbine-related equipment, such as the turbine control valve that adjusts the steam supplied to the steam turbine and the casing that houses the steam and turbine, is warmed. (
It is necessary to warm up the

This warming is performed while adjusting the steam flow rate by opening and closing the bypass valve (hereinafter referred to as the warming valve) of the main steam stop valve so that the steam pressure of the equipment to be warmed remains constant (for example, 4 to 5 atg). , raise the temperature of the device to be warmed to the target temperature, and further,
This is done by maintaining this state for several hours.

Furthermore, various constraint conditions are set when performing this warming. For example, the internal metal temperature change rate of the device to be warmed is less than or equal to a specified value, and the temperature difference between the inner and outer surfaces of the device to be warmed is less than or equal to a specified value.

These constraint conditions are set to alleviate thermal stress that occurs in the target device during warming. Failure to comply with this constraint will result in thermal fatigue and shorten the life of the equipment.

Conventionally, operators have continuously monitored these constraint conditions and manually adjusted the opening degree of the warming valve so that they are adhered to.

On the other hand, a warming control device that automatically performs this operation has also been realized, and a conventional example thereof is shown in FIG.

In the figure, steam generated from a steam source 1 passes through a main steam pipe 2 and is supplied to a turbine 5 via a main steam stop valve 3 and a turbine control valve 4. Further, a warming valve 7 is disposed in the bypass pipe 6 of the main steam pipe 2.

The turbine control valve 4 includes a pressure sensor 8 for detecting the internal steam pressure, a metal inner surface temperature sensor 9 for detecting the temperature of the inner surface of the metal, and a metal outer surface temperature sensor for detecting the temperature of the outer surface of the metal. 10 are arranged. These pressure sensors 8, metal inner surface temperature sensors 9,
A detection signal from the outer surface metal temperature sensor 10 is applied to a warming control device 11 for controlling warming.

In the warming control device 11, the pressure control section 12 calculates a warming valve operation amount signal such that the steam pressure of the turbine control valve 4 reaches a specified value based on the detection signal of the pressure sensor 8, and sends it to the opening command block section. Output to 13.

In addition, the temperature change rate calculation section 14 includes a metal inner surface temperature sensor 9.
The rate of change in temperature of the inner surface of the metal is calculated based on the detection signal, and is output to the opening command block section 13. The temperature difference calculating section 15 calculates the temperature difference between the inner and outer surfaces of the metal based on the detection signals of the metal inner surface temperature sensor 9 and the metal outer surface temperature sensor 10, and outputs it to the open command block section 13.

The open command block unit 13 monitors whether the temperature change rate of the inner surface of the metal and the temperature difference between the inner and outer surfaces of the metal are equal to or lower than respective predetermined values, and when these conditions are met, The warming valve operation amount signal outputted from the pressure control section 12 is outputted to the warming valve opening setting device 16. Thereby, the opening degree of the warming valve 7 changes by the amount of operation of the warming valve.

Further, the opening command block section 13 does not output the warming valve operation amount signal to the warming valve opening setting device 16 when at least one of these conditions is not satisfied.

In this way, the control of the pressure control section 12 is made effective only when predetermined constraint conditions are satisfied.

(Problem to be solved by the invention) By the way, the time required for warming turbine-related equipment varies depending on the heat capacity and steam conditions of the equipment to be warmed, but it is usually as short as 2 hours and as long as 2 hours. In some cases, it can take up to 8 hours or more.

Therefore, when warming manually,
Since it is necessary to monitor various constraint conditions over a long period of time, the burden on the operator is extremely heavy.

Further, when the conventional device shown in FIG. 4 is used, warming is interrupted when the constraint condition is exceeded, and warming is restarted when the constraint condition is again entered, which is repeated to raise the temperature to the target temperature.

This has caused an inconvenience in that the time required for warming becomes long.

SUMMARY OF THE INVENTION An object of the present invention is to provide a warming control device that can solve the problems of the prior art and shorten the time required for warming.

[Configuration of the Invention (Means for Solving the Problems)] The present invention detects the steam pressure of the equipment to be warmed and the process quantities for monitoring various constraint conditions, and adjusts the respective values according to the detection results. Calculates the operating amount of the warming valve independently. Then, among the calculation results, the minimum operation amount is determined and added to the warming valve.

(Operation) Therefore, the operation of the warming valve is controlled so as to always satisfy all the constraint conditions, so the time required for warming is shortened.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a warming control device according to an embodiment of the present invention. In this figure, the same parts and corresponding parts as in FIG. 4 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In the warming control device 20, the adder/subtractor 21 calculates the deviation eT' between the pressure setting value rP preset in the pressure setting section 22 and the detection signal yp of the pressure sensor 8 (see FIG. 2(a)), and calculates the deviation eT'. The deviation el' is calculated by the pressure control calculation section 23.
Output to. Note that the pressure setting value rp is set to a pressure corresponding to the target temperature.

The pressure control calculation section 23 calculates the pressure control operation amount IIIP (see FIG. 2 (b)) by calculating the following equation (1), and outputs the pressure control operation amount +111' to the low value priority section 24. .

mp=KPjep...(I) Here, KP is the pressure control proportional gain.

The temperature change rate calculating section 25 calculates the temperature change rate yR of the inner surface of the metal based on the detection signal of the metal inner surface temperature sensor 9,
The temperature change rate yR is output to the adder/subtractor 26.

The adder/subtractor 26 calculates the deviation eR between the temperature change rate setting value rR preset in the temperature change rate setting section 27 and the temperature change rate yR (see FIG. 2(a)), and calculates the deviation 8R as the change rate. It is output to the control calculation section 28. Note that the temperature change rate setting value rR is set to a value that has a certain margin with respect to the temperature change rate that is limited during warming.

The rate of change control calculation unit 28 calculates the temperature change rate control manipulated variable mR (see FIG. 2(b)) by calculating the following equation (n), and calculates the temperature change rate control manipulated variable mR by the low value priority unit. Output to 24.

mR=KR+eRH+-(■) Here, KR is a temperature change rate control proportional gain.

The temperature difference calculating section 29 calculates the temperature difference yD between the metal inner and outer surfaces based on the detection signals of the metal inner surface temperature sensor 9 and the metal outer surface temperature sensor 10, and outputs the metal inner and outer surface temperature difference yD to the adder/subtractor 30.

The adder/subtractor 30 calculates the temperature difference setting value rD and the temperature difference yn (see FIG. 2(a)) which are preset in the temperature difference setting section 31.
, and outputs the deviation eD to the temperature difference control calculation section 32. Note that the temperature difference set value rD is set to a value that has a certain margin for the temperature difference that is limited during warming.

The temperature difference control calculation unit 32 calculates the temperature difference control operation amount n+n (see FIG. 2(b)) by calculating the following equation (III),
The temperature difference control manipulated variable mD is output to the low value priority section 24.

mD=KD+eD...Medium (■) Here, KD is a temperature difference control proportional gain.

The low value priority section 24 receives the input pressure control operation amount IP.

Among the temperature change rate control manipulated variable mR1 and the temperature difference calculation unit 111D, the one that takes the smallest value is determined, and it is set as the warming valve manipulated variable m (see FIG. 2(c)) to determine the warming valve opening degree. Output to the setting device 16.

Therefore, the detection signal yp, the temperature change rate yR1, and
When the temperature difference yD is obtained as shown in FIG. 2(a), the corresponding pressure control manipulated variable ff1P, temperature change rate control manipulated variable mR, and temperature difference control manipulated variable 111D are obtained. Note that in this embodiment, temporally discrete processing is performed.

As a result, as shown in FIG. 2(c), the warming valve operation amount m becomes the pressure control operation amount ml' during the first period TI.
However, the temperature change rate control manipulated variable mR is selected in the next period T2, and the pressure control manipulated variable mP is selected and output in the subsequent period T3.

That is, at the beginning of warming, the metal temperature is lower than the temperature of the warming steam, and the warming steam condenses the moment it contacts the metal, causing the turbine control valve 4
steam pressure does not increase easily. Further, during this period, there is little change in metal temperature. Therefore, during this period when the pressure does not rise easily, the warming steam is controlled to further flow in.

As the warming steam continues to flow in this way, the metal temperature rapidly increases from a certain point. and,
When the rate of metal temperature change reaches a critical level, the flow rate of the warming steam is throttled to meet the constraint.

Next, as the metal temperature rises to near the temperature of the warming steam and the change in metal temperature becomes smaller, the flow rate of the warming steam increases.

As described above, in this embodiment, in a situation where the metal inner surface temperature change rate and the metal inner and outer surface temperature difference are smaller than predetermined specified values and no inconvenience occurs even if the steam pressure of the turbine control valve 4 is increased, The flow rate of the warming steam is controlled so that the pressure of the turbine control valve 4 is constant, and when either the metal inner surface temperature change rate or the metal inner and outer surface temperature difference is about to exceed a predetermined value, the flow rate of the warming steam is controlled. I try to narrow it down so that I don't exceed the constraints.

As a result, the warming steam is continuously supplied to the turbine control valve 4, so the time required for warming can be shortened.

FIG. 3 shows a warming control device according to another embodiment of the present invention in which the casing of the turbine 5 is the object of warming. In this figure, the same parts and corresponding parts as in FIG. 1 are denoted by the same reference numerals, and the explanation thereof will be omitted.

In the figure, a pressure sensor 8 detects the steam pressure in the casing of the turbine 5, a metal inner surface temperature sensor 9 detects the metal inner surface temperature of the casing, and a metal outer surface temperature sensor 10 detects the metal outer surface temperature of the casing. do. Further, the differential expansion meter 40 detects the difference in expansion between the vehicle interior and the rotor.

The detection signal yE of this differential expansion meter 40 is applied to an adder/subtractor 41 of the warming control device 20'. The adder/subtractor 41 calculates the deviation eE between the differential expansion film constant value rE preset in the expansion difference setting section 42 and the detection signal yE, and outputs the deviation eE to the expansion difference control calculation section 43.

The differential expansion control calculation unit 43 executes a predetermined calculation to
= Calculate the differential expansion control manipulated variable IIIE, and output the differential expansion control manipulated variable IIIE to the low value priority section 24''.

The low value priority section 24' selects the input pressure control operation amount +11.
P, temperature change rate control operation amount mR1 temperature difference control operation amount mD
, and the differential expansion control operation amount mE, which takes the smallest value is determined and outputted as the warming valve operation amount m to the warming valve opening degree setter 1/6.

In this way, when warming the casing of the turbine 5, the optimum warming valve operation amount m is applied to the warming valve opening setting device 16, and the casing is appropriately warmed.

In the above-described embodiments, the turbine control valve and the turbine casing are used as devices to be warmed, but the present invention can also be applied to the case of warming other turbine-related devices. Further, as the constraint conditions, in addition to those used in the above-described embodiments, constraints set for the turbine-related equipment can be used.

[Effects of the Invention] As described above, according to the present invention, the warming valve is controlled so that various constraint conditions set during warming are always satisfied, and warming steam is continuously supplied to the equipment to be warmed. As a result, the time required for warming can be shortened. Also,
Naturally, the effort for the operator can be significantly reduced.

[Brief Description of the Drawings] Figure 1 is a block diagram showing a warming control device according to an embodiment of the present invention, Figure 2 (a) is a graph diagram showing an example of a process signal, and Figure 2 (b) is an operation A graph diagram showing an example of the amount, (c) is a graph diagram showing an example of the output result,
FIG. 3 is a block diagram showing a warming control device according to another embodiment of the present invention, and FIG. 4 is a block diagram showing a conventional example of a warming control device. 8...Pressure sensor, 9...Metal inner surface temperature sensor,
20.20'...warming control device, 21.26
, 30.41... Adder/subtractor, 22... Pressure setting section,
23... Pressure control calculation section, 24, 24''... Low value priority section, 25... Temperature change rate calculation section, 28... Change rate control calculation section, 29... Temperature difference calculation section, 31...Temperature difference setting section, 32...Temperature difference control calculation section, 40...
Differential expansion meter, 42... Differential expansion setting section, 43... Differential expansion control calculation section.

Claims (1)

[Claims] In a warming control device that supplies steam generated from a steam generation source to turbine-related equipment via a warming valve to warm the turbine-related equipment, a pressure sensor that detects the steam pressure in the turbine-related equipment; a plurality of detecting means for detecting a plurality of process quantities to be monitored during warming; and calculating an operation amount of the warming valve in order to keep the steam pressure in the turbine-related equipment constant according to the output of the pressure sensor. a calculation means, a calculation means for calculating the operation amount of the warming valve according to each process quantity detected by each of the detection means, and identifying the minimum one of the operation amounts output from each of the calculation means. A warming control device comprising: a manipulation amount identifying means for actually applying the manipulated variable to the warming valve.