JPH0765482B2 - Steam turbine valve test equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a steam turbine valve test apparatus used for testing a main steam stop valve or a governor valve of a steam turbine in a nuclear power plant or the like.

[Conventional technology]

Figure 2 is, for example, issued on July 31, 1974, Mitsubishi Heavy Industries Technical Report Vo
FIG. 1 is a block connection diagram showing a conventional valve test device shown in No. 4 pages 90 to 100, in which 1 is a steam turbine, 2 is a generator driven by a steam turbine, and 3 is a steam turbine.
Is a main steam stop valve provided in the middle of the steam supply passage of the steam turbine 1, and includes, for example, four main steam stop valves 3a to #D.
It consists of 3d. 4 is a governor valve, for example, four #A to #D
It consists of governor valves 4a-4d. 5 is a first stage rear outlet steam pressure transmitter, 6 is a governor controller, 7 is a load limiter setting device, 8 is a subtractor, and 9 is a proportional integral controller for the first stage rear outlet steam pressure feedback (hereinafter referred to as PI controller). ), 10 is a row selector, 11 is a valve test signal generator, 12a to 12d are valve test close command signals, and 13a to 13d are #A to.
It is a #D governor valve controller.

Next, the operation will be described. The main steam stop valve 3 and the governor valve 4 need to be periodically tested during the load operation of the steam turbine 1. Therefore, each valve should be closed one by one to ensure that each valve is properly closed in an emergency. Check. That is, the output of the load limiter setting device 7 is subtracted by the subtracter 8 from the first stage outlet steam pressure feedback signal detected by the first stage rear outlet steam pressure oscillator 5, and the deviation of these is subtracted from the first stage. It is given to the PI controller 9 for the rear outlet steam pressure feed back, and the output of this PI controller 9 becomes the load limiter output.

On the other hand, the output of the governor controller 6 is set to have a level higher than the output of the PI controller 9 by, for example, about 10%, and as the output of the row selector 10, the output of the PI controller 9 is given to each valve controller. There is.

For example, when the main steam stop valve 3a of #A and the governor valve 4a are tested, the valve test signal generator 11 outputs the #A governor valve.
The valve test close command signal 12a of 4a is output. This signal gradually closes the valve in about 1 minute. It is a ramp-shaped change signal as shown in FIG. When the #A governor valve 4a is fully closed, the #A main steam stop valve 3a is fully closed in a step-like manner by another interlock and then fully opened again. After this, the valve test closing command signal 12a of the #A governor valve 4a from the valve test signal generator 11 reduces the closing signal in a ramp shape as shown in FIG. 2, and the #A governor valve 4a opens. The valve test of the main steam stop valve 3a and the governor valve 4a of #A is completed. The same applies to the other main steam stop valves 3 and governor valves 4 of #B to #D.

At this time, each set of valves will be closed, which will cause a large disturbance in the turbine output, but due to the feed back operation of the first-stage rear outlet steam pressure and the correction operation of PI control, the remaining sets #B ~ Since the opening degree of the #D valve is automatically opened, the fluctuation in the output of the generator 2 is suppressed. Therefore, so that the steam pressure at the outlet of the first stage becomes constant,
The load is controlled, and the valve test can be performed with confidence.

[Problems to be solved by the invention]

Since the conventional steam turbine valve test device is configured as described above, the first test is performed during normal operation of this steam turbine.
Although the post-stage outlet steam pressure is approximately proportional to the output of the generator 2, if one governor valve 4 is fully closed during the valve test,
Transiently the proportional relationship collapses and the 1st stage rear outlet steam pressure signal does not correspond exactly with the output of the generator 2, resulting in a generator output of several% (3 % Fluctuation is also considered a problem), and during a valve test during rated output operation at a nuclear power plant, overload operation may result due to the generator output fluctuation. There was a problem.

The present invention has been made to solve the above problems, and suppresses the fluctuation of the generator output against the disturbance during the valve test as much as possible, so that the valve test can be safely performed during the rated output operation. The purpose is to obtain a steam turbine valve test device that can.

[Means for solving problems]

The steam turbine valve test apparatus according to the present invention detects the output of the generator driven by the steam turbine by the power detector, and based on the output deviation between the power detector and the load limiter setting device, The proportional-plus-integral controller 2 is configured to correct the output of the steam load limiter setting device.

[Action]

A second proportional-integral controller in the present invention performs proportional-integral processing of a deviation between the output of the power detector and the output of the load limiter setting device, and corrects the output of the load limiter setting device by using the processing result as a correction signal. By this correction and the output correction of the load limiter setting device by the proportional-integral control of the first-stage post-output steam pressure feedback similar to the conventional one, the first-stage post-output steam pressure has a substantially linear proportional relationship with the generator output. In this way, it works to minimize the fluctuation of the generator output during the valve test.

Example of Invention

An embodiment of the present invention will be described below with reference to the drawings. First
In the figure, 14 is a power detector for detecting the output of the generator 2, 15 is the output of the load limiter setting device 7 and the power detector 14
, A second PI controller, which takes the deviation from the output of the second PI controller, which performs proportional-integral processing on the output of the subtractor 15. An adder 17 adds the output of the load limiter setting device 7 and the output of the second PI controller 16. Note that here, 9 is the first PI controller. In addition, the same blocks as those shown in FIG. 2 are designated by the same reference numerals,
The overlapping description will be omitted.

Next, the operation will be described. The opening / closing operations of the main steam stop valve 3 and the governor valve 4 during the valve test are the same as those described in the above-mentioned conventional example, and any one of the main steam stop valve 3 and the governor valve 4 is closed. In this case, the first PI controller 9 having the first-stage rear outlet steam pressure feed back performs the correction operation for the disturbance at a high speed.

On the other hand, in this embodiment, control is performed so that the transient first stage rear outlet steam pressure generated during the valve test and the current actual output of the generator 2 are in a linear proportional relationship. That is, the actual output of the generator 2 is detected by the power detector 14, and the deviation between this detected output and the output of the load limiter setting device 7 is subtracted.
2nd PI controller 16 based on this deviation
However, the output of the load limiter setting device 7 is optimally controlled according to the output state of the generator 2, and the output of the generator 2 is made to correspond to the first stage rear outlet steam pressure, and the generator 2
It operates so that the output of is stable and highly accurately kept constant.

As a result, in this embodiment, in addition to the correction by the high speed PI control in the feed back of the first stage rear outlet steam pressure in the conventional case, the correction by the low speed PI control in the feed back of the generator output can be performed, and the stability is stable. In addition, it is possible to control the generator output with high accuracy with high accuracy, suppress fluctuations in the generator output during the valve test, and prevent overload operation.

In the above embodiment, the first PI controller of the first outlet steam pressure feed back and the second PI controller of the feed back of the generator output are provided on the load limiter circuit side. It may be provided on the circuit side, and has the same effect as the above embodiment.

〔The invention's effect〕

As described above, according to the present invention, the power detector of the generator driven by the steam turbine and the output deviation between the power detector and the load limiter setting device are input to the second proportional-integral controller. Since the output of the second proportional-integral controller is used to correct the output of the load limiter setting device, the output of the first-stage rear outlet steam pressure feedback is corrected by the second proportional-integral control. There is an effect that the fluctuation of the generator output at the time of the test can be extremely small and can be suppressed with high accuracy.

[Brief description of drawings]

FIG. 1 is a block connection diagram showing a valve test device for a steam turbine according to an embodiment of the present invention, FIG. 2 is a block connection diagram showing a conventional valve test device, and FIG. 3 is a valve test signal generator. It is a time chart of a ramp signal. 1 is a steam turbine, 2 is a generator, 4 is a governor valve, 5 is a first stage rear outlet steam pressure oscillator, 7 is a load limiter setting device, 9 is a first proportional-integral controller (PI controller), 11 is a valve test signal Generators, 13a to 13d are valve controllers, 14 is a power detector, and 16 is a second proportional-plus-integral controller. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A first proportional-integral controller, based on an output deviation between a load limiter setter and a first stage rear outlet steam pressure oscillator of a steam turbine during a valve test, has a ramp-shaped signal from a valve test signal generator. According to the above, the output of the valve controller for controlling the governor valve is corrected, and in the valve test apparatus of the steam turbine that enables the valve test, the power detector of the generator driven by the steam turbine is provided. A valve test apparatus for a steam turbine, wherein a second proportional-plus-integral controller corrects the output of the load limiter setting device based on the output deviation between the power detector and the load limiter setting device.