JPH0720383Y2 - Turbine guide vane abnormality detection device - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to an abnormality detecting device for a water turbine guide vane, and is intended to promptly detect an abnormality when the guide vane is closed.

B. Conventional technology If the twigs or rocks flow into the turbine and become clogged at the guide vanes, the guide vanes may not close. This will be specifically described for the cross-flow turbine shown in FIG. In the figure, 1 is a runner, 1a is its rotating shaft, 2 is a guide vane, and the guide vane 2 adjusts the water amount and the turbine output by opening and closing around the shaft 2a. 3 is a casing, 4 is an inlet pipe, and 5 is a discharge pipe. In such a cross-flow turbine, water flows across the runner 1 as indicated by arrow A.

In such a cross-flow turbine, a screen is provided on the upstream side of the turbine to prevent the foreign matter 6 from flowing in, but the foreign matter 6 may flow in through the screen. If the foreign matter 6 that has flowed in as described above is clogged, a situation may occur in which the guide vanes 2 cannot be closed.

C. Problems to be solved by the invention By the way, conventionally, the clogging of the foreign matter 6 is detected as follows. That is, when the guide vanes 2 do not become fully closed even after the required time has elapsed after the guide vanes 2 are closed, it is determined that the foreign matter 6 is clogged and the guide vanes 2 are not closed. As the "required time", the time from when the guide vane 2 is fully opened to when it is fully closed is set.

As described above, conventionally, it takes a long time (required time) to determine an abnormal state as described above. Therefore, especially at the time of emergency stop, the response is delayed and the runaway time of the water turbine becomes long, which is dangerous. Further, even when the guide vane 2 is closed even when the guide vane 2 is clogged with the foreign matter 6, the guide vane 2 does not rotate even if a closing force acts on the guide vane 2, so that the guide vane 2 and the casing are closed. A large stress may be applied to 3 and the turbine may be mechanically damaged.

In view of the above-mentioned conventional technique, the present invention provides an abnormality detecting device for a water turbine guide vane that can quickly detect an abnormality such as clogging of foreign matter when the guide vane is closed.

D. Means for Solving Problems In the present invention for solving the above problems, when an emergency stop command is input, the guide vane opening θ _{0 at} this time is changed to an absolute value. And the absolute value of the ratio with the opening change Δθ of the guide vane in a minute time Δt when the guide vane starts to close and the guide vane closes. Seeking It is characterized in that it is determined to be abnormal when it becomes.

E. Function In the present invention, when there is no abnormality such as foreign matter clogging, When foreign matter becomes clogged By utilizing that When it becomes, it is determined that an abnormality has occurred.

F. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. As shown in the figure, an inlet valve 11 is installed upstream of the pipeline 10. When the inlet valve 11 is open, water is guided in the line 10 and the inlet pipe 4, passes through the guide vanes 2, passes through the runner 1 in the casing 3 and is discharged through the discharge pipe 5. .

An opening detector 12 is installed in the guide vane 2, and the opening detector 12 detects the opening signal a indicating the opening θ of the guide vane 2.
To the microcomputer 13. A head detector 14 is installed near the cross flow turbine in the pipeline 10. The head detector 14 detects the head by detecting the water pressure, and sends a head signal b indicating the head to the microcomputer 13. The generator control panel 15 sends a hydraulic turbine movement command c and a hydraulic turbine emergency stop command d to the microcomputer 13. The microcomputer 13 has
Absolute value of the differential coefficient obtained by differentiating the guide vane opening θ in the normal guide vane closing mode with respect to time t The calculation program for obtaining is preset.
Further, the microcomputer 13 is set with a program for performing an operation described later, and outputs an inlet valve command e and a foreign matter alarm f.

Next, the operation of this embodiment will be described with reference to FIG. 1 and FIG. 2 which is a flow chart showing the operation state.

[I] Normal operation: When the water turbine operation command c is input from the generator control panel 15 to the microcomputer 13, the microcomputer 13 receives the inlet valve command e from the inlet valve 11
And the opening of the guide vane 2 is adjusted so that the turbine operates optimally.

[II] Operation during emergency stop: (1) When an emergency such as a short circuit accident occurs, the generator control panel
An emergency stop command d is sent from 15 to the microcomputer 13.

(2) When the microcomputer 13 receives the emergency stop command d for the water turbine, the microcomputer 13 determines from the opening signal a the opening θ of the guide vane 2 at this time.
While reading ₀ , the head is obtained from the head signal b.
And by the preset calculation program Ask for. In this embodiment, the correction amount considering the value of the head is an absolute value. The program is organized to be included in. Derivative Shows the slope of the characteristic line in FIG. The slope of the characteristic straight line varies depending on the initial opening amount of the guide vane 2 and the drop. For example, when the emergency stop command d is input to the microcomputer 13, it depends on whether the guide vanes 2 are fully open or half open, and whether the head is large or small.

(3) Microcomputer 13 is an absolute value And the closing of the guide vane 2 is started. There is a dead time of t ₁ (second) from the reception of the emergency stop command d until the guide vane 2 starts the actual closing operation.

(4) The timer of the microcomputer 13 starts after the dead time has elapsed, and the opening θ ₁ of the guide vane 2 at the time of starting the timer is fetched. ΔT from timer start
When the second has elapsed, the opening degree θ ₂ of the guide vane ₂ is taken in.

And Ask for.

Is performed every ΔT sample period.

(5) Value that the microcomputer 13 obtains for each sampling period ΔT And calculated earlier To compare.

(6) When there is no foreign object 6 in the turbine Becomes On the other hand, when the foreign matter 6 is clogged in the water turbine 6 and the guide vane 2 hits the foreign matter 6, the rotational movement of the guide vane 2 becomes slow or becomes zero. Becomes smaller.

(7) So the microcomputer 13 When it becomes, it is determined that the foreign matter 6 is clogged. When the clogging of the foreign matter 6 is determined, the microcomputer 13 fully closes the inlet valve 11 in response to the inlet valve command e and issues an abnormal alarm f.

As described above, in the present embodiment, it is prompt that the guide vanes 2 do not close due to foreign matter or the like, that is, the guide vanes 2
It can be detected when the rotational speed of the closing direction becomes slower than the normal speed or becomes zero.

In addition, in the above embodiment, the head is also taken into consideration. Was calculated, but for those with small fluctuations in the head and those with little effect from fluctuations in the head, only the opening of the guide vanes was used. May be requested.

G. Effect of the Invention According to the present invention as described concretely with the above embodiments, according to the present invention, in the closed mode at the time of closing the guide vane in the normal state. And at the time of actual closure Compare Since the abnormal closing of the guide vane can be detected at the time of, it is possible to detect the abnormal quickly without waiting for the full closing time of the guide vane.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention, FIG. 2 is a flow chart showing the operation of the embodiment, FIG. 3 is a characteristic diagram showing a closing characteristic of a guide vane, and FIG. 4 is a cross flow turbine. It is a block diagram. In the drawings, 1 is a runner, 2 is a guide vane, 6 is a foreign matter, 12 is an opening detector, and 13 is a microcomputer.

Claims (1)

[Scope of utility model registration request] 1. A water turbine equipped with a guide vane that adjusts the amount of water flowing into the runner by rotating on the upstream side of the runner, and an opening detector that detects the opening θ of the guide vane, and Absolute value of the derivative of the guide vane opening θ in the guide vane closing mode The calculation program for
When an emergency stop command is input, the guide vane opening θ ₀ at this time is input to the calculation program and the absolute value is input. The absolute value of the ratio of the guide vane opening change Δθ to the guide vane closing time and the guide vane closing time when the guide vane is closing Seeking An abnormality detection device for a water turbine guide vane, comprising: a computer that determines that the abnormality has occurred.