JPH0196403A - Warming device for turbine regulation valve - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to steam turbines, and particularly to a regulating valve warming device suitable for thermal power and nuclear power turbines used at high temperatures.

[Conventional technology]

As described in JP-A-61-163010, in conventional devices, the temperature of the control valve was increased by repeatedly opening and opening the warm-up valve fully, or the opening degree of the warm-up valve was manually adjusted. was adjusting.

[Problem that the invention seeks to solve]

Conventionally, operators visually observed the rate of change in temperature on the inner wall of the control valve.
Because the warm-up valve opening setting device had to be adjusted manually, or it had to be fully opened and opened repeatedly, it was difficult to keep the temperature change rate of the inner wall of the control valve within the specified value, and the inner wall change rate limit value was exceeded.
The limit value for temperature difference between the inner and outer walls of the control valve was exceeded, causing an excessive thermal shock.

Figure 2 shows the case where the warm-up valve is fully opened and then fully opened repeatedly to warm up the control valve. In this case, the warm-up valve is fully opened and closed in a short period of time, so the amount of warm-up steam can be determined with good accuracy. Adjustment becomes impossible, and the limit value for the temperature change rate on the inner wall of the control valve is exceeded many times, and the limit value for the temperature difference between the inner and outer walls of the control valve is also exceeded many times.

This caused excessive thermal shock to the control valve, shortening its lifespan.

On the other hand, if the opening degree of the warm-up valve is adjusted conservatively, the rate of change in temperature of the control valve will be too small and the warming time will be prolonged.

Furthermore, even if the temperature change rate is adjusted to a specified value, this warming operation normally takes several hours, which is a heavy burden on the operator.

An object of the present invention is to solve the above problems.

[Means for solving problems]

The above purpose depends on the amount of deviation between the saturated steam temperature change rate set value in the control valve chamber and the saturated steam temperature determined from the control valve chamber pressure.
By calculating the required warm-up valve opening operation amount, by making the warm-up valve control cycle almost the same as the time constant of the change in temperature of the inner wall of the control valve, and by determining the deviation value between the warm-up steam and the inner wall temperature of the control valve. By correcting the warm-up valve opening calculation gain, and when the difference between the warm-up steam temperature and the control valve inner wall temperature becomes less than a specified value, the warm-up valve is opened to the maximum opening, and the control valve is opened to its maximum opening. This is achieved by locking the warm-up valve opening operation when the temperature difference between the inner and outer walls exceeds a specified value or when the temperature difference between the inner and outer walls of the regulating valve exceeds a specified value.

[Effect]

The required warm-up valve opening operation amount is calculated based on the deviation between the rate of change of the saturated steam temperature in the regulating valve chamber and the saturated steam temperature determined from the pressure in the regulating valve chamber. The amount of warm-up steam required to increase the rate of change in valve inner wall temperature along a specified value, that is, the necessary warm-up valve opening degree is calculated.

The cycle of the warm-up valve control is such that the warm-up valve is adjusted according to the previous control, and the inner wall temperature of the adjustment valve increases accordingly.

It will take some time until it stabilizes.

The gain of the warm-up valve opening control calculation is corrected using the deviation value between the warm-up steam temperature and the inner wall temperature of the control valve. This is because the amount of change in temperature on the inner wall of the control valve is large.

By these means, the inner wall temperature of the regulating valve can be automatically increased at a desired rate of change, and the temperature difference between the inner and outer walls of the regulating valve can be suppressed within a specified value.

If the rate of change in temperature of the inner wall of the regulator exceeds the specified value due to some abnormality, or if the temperature difference between the inner and outer walls of the regulator exceeds the specified value, the warm-up valve opening control is locked. It is possible to prevent the rate of temperature change and the temperature difference between the inner and outer walls of the control valve from reaching the limit value.

When the difference between the warm-up steam temperature and the inner wall temperature of the control valve becomes less than the specified value, the warm-up valve opening degree is increased to the maximum.When this difference becomes smaller, the warm-up valve is adjusted to the above-mentioned indoor saturated steam temperature of the control valve. Even if the rate of change is controlled, the change in the temperature on the inner wall of the regulating valve cannot be much lower than the set value, so the warming operation of the regulating valve can be shortened.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

This figure shows the case where it is applied to a nuclear turbine.
Steam from the nuclear reactor is guided to a main steam stop valve 2 through a main steam pipe provided with a main steam temperature detector 1 .

The main steam stop valve 2 has a warm-up valve 4 built into the main steam stop valve body 3, and when the valve body 5 of the warm-up valve 4 is raised to its maximum position, the valve body 3 of the main steam stop valve is also fully opened. It has a structure.

The main steam stop valve rod 5 has a coupling 6 with a gap, and the warm-up valve 4 will not open unless the piston 7 rises from the lower limit position to the opening point.

A piston position detector 9 is attached to the piston 7, and the main steam stop valve/warm-up valve drive device 8 is adjusted to match the setting value from the piston position setting device 22. Therefore,
The piston position setting device 22 can be said to be an opening setting device for a warm-up valve.

The steam leaving the main steam stop valve 2 passes through the piping 10 to the control valve 1.
I am guided by 1. The control valve body 12 is moved by a control valve driving device 14 via a control valve body 13 to which a control valve opening detector 15 is attached. Furthermore, temperature detectors 16 and 17 and a control valve chamber pressure detector 21 are attached to the outer and inner walls of the control valve.

A control valve drain valve 19 is provided near the control valve body 12 to which a drain discharge pipe 18 and a valve opening detector 20 are attached in order to discharge accumulated drain.

The turbine control valve warming device 23 receives the signal from the main steam temperature detector 1, the signal from the warm-up valve piston position detector 9, the signal from the control valve opening degree detector 15, and the temperature of the control valve inner and outer walls. Input the signals from the detectors 16 and 17, the signal from the adjustment valve drain valve opening detector 2o, and the signal from the adjustment valve chamber pressure detector 21, and send them to the warm-up valve piston opening setting device 22. outputs the calculated predetermined request signal, a fully open command signal to the regulating valve drive device 14, and a fully open command signal to the regulating valve drain valve 19.

A flowchart of the control contents of the turbine control valve warming device 23 is shown in FIG.

(1) to 0 indicate the order of the warming control flow of the turbine control valve.

■Adjustment valve warming use When PB is turned on, ■Main steam stop valve 2. The opening degrees of the regulator valve 11 and the regulator drain valve 19, the main steam temperature Tw, the regulator valve inner wall temperature TI, the regulator outer wall temperature To, the warm-up valve piston position PO, and the regulator valve chamber pressure are read in Δ every time. ■Main steam stop valve 2. If the control valve 11 is not fully open, the Φ main steam stop valve 2 and the control valve 11 are operated to fully open.

In order to fully close the main steam stop valve 2, the warm-up valve piston position is changed from 100% to 0%.

Next, if the ① adjustment valve drain valve 19 is not open, the 0 adjustment valve drain valve 19 is opened.

Now, when the warm-up valve 4 is opened, the main steam will flow through the control valve 11 and control valve drain valve 19 without stagnation.

■The warm-up valve piston 7 is at the position P=Po where the warm-up valve starts to open.
If it is less than that, an increase command is output to the O warm-up valve screw 8 position setter 22 and P=Po is set, thereby increasing the warm-up valve pressure to Pa.

As a result, ■ When the warm-up valve piston 7 reaches Pa, ■
The rate of change of saturated steam temperature in the control valve chamber: T' is calculated; (1) the main steam temperature - the control valve inner wall temperature difference: ΔTwx; and [phase] the control valve inner and outer wall temperature difference: ΔTro is calculated.

■The deviation between the calculated adjustment valve chamber saturated steam temperature change rate: T' and the adjustment valve chamber saturated steam temperature change rate setting value: T's is calculated, and ■ Proportional: P, integral: engineering calculations are performed. The proportional/integral calculation gain is ΔTa, which has already been calculated in ■.
Corrected by I.

This correction function is ΔTw! When the horizontal axis is plotted and the gain is plotted on the vertical axis, the curve slopes downward to the right, so if the difference between the main steam temperature and the inner wall temperature of the control valve: ΔTt+ is large, the amount of operation per warm-up valve piston 7 will be , the temperature difference Δ: is smaller than when Twt is small.

The results of the P and I calculations are subjected to an O addition calculation and set in the warm-up valve piston position setter 22.

The calculations and operations of (1) to (O) are repeated at intervals of Δ, and the position of the warm-up valve piston 7 increases.

As a result of such operations, if the rate of change in temperature on the inner wall of the control valve: T1' exceeds the specified value TI'8,
◎Lock the P and I addition calculation outputs.

This locks the increase command to the warm-up valve piston position setter.

After locking, the rate of change in temperature on the inner wall of the control valve Tl'
If it becomes less than the specified value TI'8, the output of the P/engine calculation is again output to the warm-up valve piston position setting device 22, and the warm-up valve opening degree increases.

On the other hand, if such an operation causes the temperature difference between the inner and outer walls of the 0 adjustment valve: ΔTto to exceed the specified value: ΔTl0A, @(@PI will lock the addition calculation output.

After locking, the temperature difference between the inner and outer walls of the control valve after Δ time: ΔT
If IO does not fall below the specified value ΔTl0A, the output of the P/engineering calculation is again output to the warm-up valve piston position setting device 22, and the warm-up valve opening degree increases.

Due to this operation, the inner wall temperature of the control valve rises, and @
Main steam temperature - control valve inner wall temperature difference: ΔTN+ is specified value: Δ
When Twts is reached, an increase command is given to the warm-up valve piston position setter 22 to increase the warm-up valve piston position to P=Pp, which is a position corresponding to 100% warm-up valve opening.

As a result, when the 00 warm-up valve piston position reaches P=Pr, the O adjustment valve warming is completed.

FIG. 4 shows the above-described control valve warming control process in chronological order.

Φ˜0 corresponds to the explanation or symbol regarding the warming control process described above.

0 represents the main steam stop valve fully closed operation, 0 represents the warm-up valve piston increase operation until the warm-up valve begins to open, o~o, o-o, @
-011PI system Indicates the result of the operation.

O indicates that the rate of change in temperature on the inner wall of the control valve has exceeded the specified value and the opening of the warm-up valve has been locked, and O indicates that the temperature difference between the inner and outer walls of the control valve has exceeded the specified value and the opening of the warm-up valve has been locked. ing.

0 indicates that the main steam temperature - the control valve inner wall temperature is below the specified value and the warm-up valve is fully opened.

According to this embodiment, DSS in a thermal power plant.

During the operation of WSS, etc., the warming time of the control valve is shortened, which greatly contributes to shortening the time until the ignition rod is inserted.In addition, in the case of nuclear couplants, the time from control rod withdrawal to control rod insertion is shortened and labor is saved. There is a ripple effect, such as contributing greatly to this demand.

〔Effect of the invention〕

According to the present invention, the temperature change rate on the inner wall of the control valve is kept constant, and
It is possible to keep the temperature difference between the inner and outer walls of the control valve within the limit value and automatically warm the control valve, significantly reducing the warming time compared to manual operation, extending the life of the control valve and saving more time. This has the effect of reducing the labor required for warming operations.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of an embodiment of the present invention, Fig. 2 is a conventional diagram showing changes in temperature of the inner wall of the control valve and change in temperature of the outer wall of the control valve in response to changes in the opening degree of the warm-up valve, and the third diagram is The control flowchart of the valve warming device, FIG. 4, shows changes in the inner wall temperature of the regulating valve, outer wall temperature of the regulating valve, pressure in the regulating valve chamber, and changes in saturated steam temperature in the regulating valve chamber with respect to changes in opening of the warming valve when the present invention is used. It is a diagram. 1... Main steam temperature detector, 2... Main steam stop valve, 3...
・Main steam stop valve body.

Claims (1)

[Scope of Claims] 1. A warm-up valve that can adjust the amount of warm-up steam, a steam stop valve that can shut off steam, and a drain valve on the inlet side to adjust the amount of steam. In a steam turbine having a control valve capable of adjusting the temperature of the control valve, means for detecting the temperature of warm-up steam, an inner wall temperature of the control valve, and an outer wall temperature of the control valve, and a means for detecting a change in the inner wall temperature of the control valve. rate calculation means, inner and outer wall temperature difference calculation means of the control valve, control valve inner wall temperature change rate setting means, control valve chamber pressure detection means, means for determining saturated steam temperature from control valve chamber pressure; Temperature change rate calculation means; means for calculating the deviation between the saturated steam temperature change rate setting and the calculated saturated steam temperature change rate; After fully closing the control valve and the steam stop valve and opening the drain valve, the set rate of change in saturated steam temperature and the actually measured change in saturated steam temperature are determined. A turbine control valve warming device that controls the opening degree of the warm-up valve based on the amount of deviation from the engine speed. 2. The turbine control valve warming device according to claim 1, wherein the opening degree control of the warm-up valve is performed at a constant cycle. 3. The turbine control valve warming device according to claim 1, wherein the gain for calculating the required warm-up valve opening is made variable depending on the difference between the warm-up steam temperature and the control valve inner wall temperature. . 4. In claim 1, the opening degree control of the warm-up valve is performed when the rate of change in the inner wall temperature of the regulating valve deviates from a set value with a margin, or When the difference between the inner wall temperature and the outer wall temperature of the adjustment valve exceeds a specified value, the warm-up valve is held at that position, and when it becomes less than the specified value, the saturated steam temperature change rate control of the adjustment valve chamber is restarted. A turbine control valve warming device characterized by: