JPS6032978A - Operation control method of multi-stage hydraulic machine - Google Patents

Abstract

PURPOSE:To suppress water hammer caused by the flow by performing the opening control of guide vane corresponding to the variation of rotary speed. CONSTITUTION:A rotary speed control command is transmitted to a movable guide vane 2 at the low pressure stage to perform the opening control corresponding to the rotary speed variation. An inlet valve 7 is controlled independently such that it is held at predetermined opening smaller than the opening area of the movable guide vane 2 not to induce the flow variation or that the existing flow variation is suppressed positively on the basis of control command different from the control command of rotary speed. Consequently, variation of hydraulic pressure is prevented while the rotary speed control by means of the guide vane 2 is performed under stabilized condition of hydraulic pressure resulting in quick synchronization to the specific rotary speed.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a multi-stage hydraulic machine, and in particular to a large mouth valve and at least the lowest pressure stage f: a hydraulic load at the time of starting a water turbine of a multi-stage hydraulic machine equipped with a movable guide vane. This invention relates to an operation control method when synchronously paralleling the grid after a shutdown.

[Technical background of the invention and its problems] In general, the operation control of hydraulic machines such as water turbines and pump turbines is
This is done by adjusting the opening degree of guide vanes arranged in a circular row 6 around the launch to adjust the flow rate of water that flows through the launch. Therefore, if the opening degree of the guide vane suddenly changes, the bit depth will also change suddenly, so in waterways where hydraulic machinery is connected, water hammer phenomenon due to changes in flow rate (: surging can also occur in waterways equipped with surge tanks). This will cause water pressure fluctuations and put the hydraulic machine into an unstable operating state.

On the other hand, when a hydraulic machine is operating a water turbine that is disconnected from the power grid, the operating speed of the water turbine is controlled to the rated speed by controlling the opening of the guide vane in order to synchronize it in parallel with the power grid. . In other words, a control command for one rotational speed is transmitted to the guide vane f2, and when the speed fluctuates upwards from the specified speed, the guide vane is controlled to close, and when the speed fluctuates downward, the guide vane is controlled to open. is in control. If the opening degree of the guide vane is controlled in this way for the purpose of controlling the rotational speed,
As mentioned above, fluctuations in water pressure are induced and the fluctuations in the rotational speed of the water turbine are increased as a result, and the water turbine falls into an unstable operating state, making it impossible to shift to synchronous parallel operation. This is often the case.

[Object of the Invention] The purpose of the present invention is to suppress water hammer caused by flow rate 52 when controlling the operation of a multi-stage hydraulic machine, and to operate a multi-stage hydraulic machine that can perform prompt and stable synchronization and parallel operation during water turbine operation. The objective is to provide a control method.

[Summary of the Invention] In order to achieve the above object, the present invention provides a movable guide vane of A rotational speed control designation is transmitted to change the rotational speed (52) and the corresponding opening control is performed, while a control command different from that for the movable guide vane is transmitted to the artificial valve to change the water level (1) to perform the corresponding opening control. It is characterized by the fact that it controls the rotation speed.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In this embodiment, a two-stage hydraulic machine shown in FIGS. 1 and 12 will be explained as an example of a multi-stage hydraulic machine. Reference numeral 1 denotes a low-pressure stepped section runner, 2 a movable turning section id vane, 3 a high-pressure stepped section runner, and 4 a turning section guide vane.

Further, the high-pressure stage section is connected to a water pressure pipe 8 via a swirl casing 6 and an inlet valve 7, and the low-pressure stage section is connected to a discharge tunnel (not shown) through a suction pipe 9.

In the multi-stage hydraulic machine configured in this manner, the movable guide vane 2 and the inlet valve 7 form the narrowest flow path, so the water flow is most contracted when the movable guide vane 2 and the large mouth valve 7 pass through. Therefore, when the movable guide vane 2 and the inlet valve 7 are controlled simultaneously, the flow rate is controlled by both. Therefore, when the movable guide vane 2 and the inlet valve 7 are controlled with different opening areas, the flow rate is controlled by the one with the smaller opening area. Therefore, if the opening area of the opening area of the opening area is maintained and controlled independently, this control will control the water flow into the runner without changing the flow rate. Since it is possible to change the rotational speed of the waterwheel, it is also possible to adjust the launch rotational torque that governs changes in the rotational speed of the waterwheel, and as a result, the rotational speed of the waterwheel can be adjusted and controlled.

That is, as shown in Fig. 2-5, a rotational speed control command (A) is transmitted to the movable guide vane 2 of the low pressure stage section 5 to control the opening degree corresponding to the rotational speed fluctuation, and the flow rate change is controlled in the large mouth valve 7. In order not to induce this, C2 maintains a predetermined opening smaller than the opening area of the movable guide bay 72, or when a change in flow rate occurs, C2 controls the opening in the direction of actively suppressing accumulation of two. When the artificial valve 7 is independently controlled under a control command (B) different from the rotational speed control command, f2 prevents water pressure fluctuations, and the guide vane 2I
It becomes possible to perform rotational speed control under a stable water pressure state and quickly achieve synchronization to a specified rotational speed.

[Effects of the Invention] As described above, according to the present invention, it is possible to perform stable control of the operating state at the time of starting the water turbine of a multi-stage hydraulic machine or at the time of synchronous parallel shift after load cutoff. It becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a schematic structure of a two-stage hydraulic machine applied to an embodiment of the present invention, and FIG. 2 is a diagram illustrating water pressure fluctuations in a two-stage hydraulic machine for explaining an embodiment of the present invention. FIG. 3 is a diagram showing operating characteristics of rotation speed fluctuation, guide vane, and inlet valve opening area. 1...Lower runner 2...Lower movable guide vane 3
...Upper runner 5...Return passage 6...Casing 7...Inlet valve agent Patent attorney Noriyuki Chika (and one other person) Pressure fluctuations in Figure 1 and Figure 2 -11111 1～------------
−−−−−−−m−− intercostals

Claims (1)

[Claims] It has a plurality of runners, the runner chambers of each runner are connected by a return passage, and there are two casing entrances C2 connected to the highest pressure stage part, and at least two movable guide vanes in the lowest pressure stage part C2. In a method for controlling the operation of a multi-stage hydraulic machine with A command is transmitted to control the opening degree corresponding to the change in rotational speed MJJJ, and a control command different from that of the movable guide vane is transmitted to the artificial valve to perform opening control corresponding to the fluctuation in water level 52 to control the rotational speed. A method for controlling the operation of a multi-stage hydraulic machine, characterized in that: