JPS58138274A - Operation control method of multi-stage hydraulic machine - Google Patents

Abstract

PURPOSE:To accurately control a water level, by transmitting a control instuction in accordance with a static head to a movable guide vane in the highest pressure staged part and a control instruction of a difference between water pressure in an intermediate part and water pressure in the lowest pressure part to a movable guide vane in the lowest pressure staged part to perform opening control. CONSTITUTION:At steady operation when a water level is regulated correspondingly to a change of a static head, a control instruction corresponding to the change of the static head is transmitted to a movable guide vane in a high pressure stage to operate opening control, on the other hand, a control instruction of a difference between water pressure in an intermediate part from a high pressure staged part to a low pressure stated part and water pressure in an outlet side of a low pressure staged part is transmitted to a movable guide vane 12 in a low pressure stage to operate opening control. In this way, an accurate operational condition corresponding to the static head can be always obtained.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for controlling the operation of a multi-stage hydraulic machine, and in particular, the present invention relates to a method for controlling the operation of a multi-stage hydraulic machine, and in particular, the present invention relates to a method for controlling the operation of a multi-stage hydraulic machine. The present invention also relates to a method for adjusting and controlling a steady operating state in a multi-stage hydraulic machine having movable guide vanes in the highest pressure stage section and the lowest pressure stage section.

[Technical background and problems of the invention]

The highest pressure among hydraulic machines! Each step from the R section to the lowest pressure section is equipped with a runner! In a multistage hydraulic machine in which each stage is connected by a return passage, the opening of the water port is adjusted by a guide vane installed outside the runner of each stage, thereby controlling the water flow condition of each stage. One possible method is to control the operation. However, it is extremely difficult to provide a guide vane on the outer periphery of the runner of each step and to connect an opening/closing operation mechanism to the guide vane of each step due to structural constraints.

In addition, some conventional multi-stage hydraulic machines have a structure in which only fixed vanes are provided on the outer periphery of the launch of each stage, and operation is controlled by opening and closing a large mouth valve installed at the inlet of the hydraulic machine. Since the water flow rate is adjusted only by the large mouth valve, there is a problem in that the hydraulic performance of the multistage hydraulic machine is significantly degraded at small and large flow rates far from the design point.

As a solution to the problems of the operation control method using the inlet valve control method, a multi-stage hydraulic machine is constructed in which a guide vane that can be adjusted on the water inlet side is provided only at the highest pressure stage, and the movable guide vane controls the flow rate to -11. This may be caused by vibration during low flow rate operation.

There are many problems such as noise and cavitation.

Therefore, as a multistage hydraulic machine that is structurally reasonable and reasonable (and has relatively high hydraulic performance), we installed movable guide vanes in the highest pressure stage and lowest pressure stage that can open the water port by ki + 1 knots. A multi-stage hydraulic machine is considered.

When performing water level adjustment control during steady operation in response to changes in the static head acting on the entire multi-stage hydraulic machine that has movable guide vanes in the highest pressure stage and lowest pressure stage, it is necessary to Compared to this, the flow path shape is more complicated and there are two movable guide vanes.
Considering that there are multiple sets, it is necessary to accurately adjust the opening ft of each movable guide vane in the highest pressure stage part and the lowest pressure stage part. If opening adjustment is not performed reliably, the proportion of the head that acts on the entire multi-stage hydraulic machine that is shared by the launches of each stage (head share) will vary and become uneven, leading to a decline in hydraulic performance. excessive water pressure rise in the low-pressure side step, vibration,
The operating condition is likely to be accompanied by noise, cavitation, etc., resulting in a temporary suspension.

However, there are many technologically unexplored fields in multi-stage hydraulic machines that are equipped with movable guide vanes in the highest pressure stage and the lowest pressure stage, and water level adjustment control during steady operation is particularly important for operation. A simple and accurate operation control method for this case has not yet been proposed.

[Purpose of the invention]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to perform accurate water level adjustment control under stable operating conditions by reliably vertically adjusting the opening of the movable guide vane when performing water level adjustment control in response to changes in static head during steady operation. An object of the present invention is to provide a method for controlling the operation of a multi-stage hydraulic machine that can be implemented in a number of ways.

[Summary of the invention]

In order to achieve the above object, the present invention provides that when performing adjustment control of the operating state corresponding to changes in the static head acting on the entire multi-stage hydraulic machine during steady operation, the movable guide vanes of the highest pressure stage are While controlling the opening of the movable guide vane in the highest pressure stage by transmitting a control command according to the By transmitting a control command for the water pressure difference between the water pressure and the water pressure on the outlet side of the lowest pressure stage section and controlling the opening of the lowest pressure stage movable guide vane, it is possible to correspond to the change in the static head difference and maintain the steady operating state. l1li! ! 1
! The fact that the control is performed is 1-* slight.

In addition, the present invention provides a control system for the movable guide vane of the lowest pressure stage section in accordance with the static head difference when performing regular control of the operating state in response to changes in the static head acting on the entire multistage hydraulic machine during steady operation. While transmitting the command to control the opening of the movable guide vane in the lowest pressure stage, the movable guide vane in the other highest pressure stage receives water pressure and minimum water pressure in the intermediate area between the highest pressure stage and the lowest pressure stage. 1 liter of water pressure difference with the water pressure on the outlet side of the pressure stage section
The 4I feature is that by controlling the opening of the movable guide vane at the highest pressure stage in response to the tlJ command, WA regulation # in the steady operating state is performed in response to the change in static head. It is something to do.

[Example of corner cutting]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for controlling the operation of a multi-stage hydraulic machine according to the present invention will be described below with reference to the drawings, taking a 7 Lances type two-stage pump turbine as an example.

On the axis of a single water turbine main shaft 1, a high pressure stage runner 2 and a low pressure stage runner 3 are solidly layered at a distance in the axial direction. The high pressure stage runner 2 is surrounded by an upper cover 4 and a lower cover 5, while the low pressure stage runner 3 is surrounded by an upper cover 6 and a lower cover 7, forming a high pressure stage runner chamber 8 and a low pressure stage runner chamber 9. There is. The high-pressure stage runner chamber 8 and the low-pressure stage runner chamber are connected by a return passage lO, and on the passage there are provided return vanes 11 and a low-pressure stage movable guide vane 12 that can change the water port distance f.

In addition, a spiral casing 13 is placed outside the high pressure stage runner chamber 8.
is arranged, and the connection between the thin chamber 14 and the high-pressure stage runner chamber 8 is delayed, and the entrance of the thin chamber is connected to the penstock 21 via the Oguchi Nakanatsu, and the penstock 21 is connected to the upper pond 18. .

Furthermore, on the outside of the high-pressure stage runner 2, a high-pressure stage movable guide vane 15 is provided which can change the water port opening.

A suction pipe 16 is connected to the low-pressure stage runner chamber 9, and its downstream side is connected to a water discharge channel 22, so that the water discharge wI22
is in contact with Shimoike 19. Il again! The figure in the middle of Figure 2 is the two-stage pump water turbine itself, and the figure in the middle is the rotating am.

A return passageway 10 corresponding to the intermediate portion between the high-pressure stage runner chamber 8 and the low-pressure stage launch chamber 9 is provided with an intermediate water pressure detection device [17] for detecting water pressure in the return passageway.

Next, an embodiment of the operation control method according to the present invention for a two-stage pump turbine will be described.

That is, when performing water level adjustment control corresponding to changes in the static head during steady operation, as shown in FIG. The command is sent to the guide vane control system [26
The high-pressure stage movable guide vane 15 is controlled by the following information.

By controlling the opening degree of the high-pressure stage movable guide vane 15, the head difference sharing between the high-pressure stage runner section and the low-pressure stage launch section changes. In other words, if the water port opening of the high pressure stage movable guide vane 15 becomes large, the head share of the high pressure stage launch section will be relatively smaller than that of the low pressure stage launch part, and conversely, if the water mouth opening becomes smaller, the head difference share of the high pressure stage part will decrease. increases relatively. Therefore, the water pressure in the return passage section located in the middle between the high pressure kill section and the low pressure stage section changes.

Here, regarding the other lowest pressure membrane movable guide vane, that is, the low pressure stage movable guide vane 12, the intermediate water pressure between the high pressure stage section and the low pressure stage section (for example, the return passage 1
0 water pressure) and the water pressure on the outlet side of the low-pressure stage section (for example, the water pressure at the outlet of waterway 4), the opening degree of the guide vane 12 is controlled so that the hole has a hydraulically appropriate % difference. Do the following.

In other words, as a specific example, as shown in Figure IK4, the intermediate water pressure between the high pressure stage and the low pressure stage detected by the intermediate water pressure detection device 17 (for example, the water pressure in the return passage 10), and the lowest pressure stage The water pressure difference in the outlet water pressure (for example, the water pressure of the water discharge channel) detected by the outlet side water pressure detection device 27 is detected by the water pressure difference detection device, and on the other hand, it acts on the entire multistage hydraulic machine detected by the static head difference detection device fl129. static head difference (difference between the water level of Upper Pond Jin and the water level of Lower Pond 19, indicated by Hat in Figure 2)
and compare the above water pressure difference with a water pressure difference comparator (supplied). Next, a preset range ( 1 (an example is shown in Fig. 5.6), that is, when the intermediate water pressure decreases and the head share of the low-pressure stage runner decreases, the low-pressure stage movable guide vane 1
In the 2t-closing direction, or conversely, when the above relative ratio or relative difference is below the specified range, that is, when the intermediate water pressure increases and the head share of the low pressure stage launch section increases, the four-part movable guide A control command for operating the vanes 12 in the opening direction is transmitted to the guide vane control device 31, and the opening degree of the low pressure stage movable guide vane 12 is controlled until the relative ratio or relative difference is again within the specified range.

In this way, a control command corresponding to the change in the static head difference is transmitted to the high pressure stage movable guide vane to control its opening, while at the same time controlling the intermediate water pressure between the high pressure stage section and the low pressure stage section and the low pressure stage movable guide vane. By transmitting a control command for the water pressure difference with the water pressure on the side outlet side to the low-pressure stage movable guide vane 12 and performing belly-opening control thereof, an appropriate operating state corresponding to the above-mentioned static head difference can be always achieved.

Next, an embodiment t of an operation control method in which a control command from a water level adjustment device is transmitted to the low pressure stage movable guide vane 12 will be described, contrary to the above embodiment.

As shown in FIG. 3, the low-pressure stage movable guide vane 12 controls the opening degree of the four-part movable guide vane 12 by transmitting a control command from the water level regulator to a guide vane control trowel.

Regarding the other high-pressure stage movable guide vane 15, the opening degree of the four-part movable guide vane 15 is controlled in accordance with the control block diagram shown in FIG. 4, as described above. However, in this case, the relative ratio or relative difference between the static head difference compared between the water pressure difference comparators, the intermediate water pressure from the high pressure stage to the low pressure stage, and the water pressure at the outlet of the low pressure stage is determined at each stage. The specified box St is set in advance so that the head is shared so that high-performance operation can be performed in the section.
- If it is a high pressure stage movable guide vane 1
A control command is transmitted to the guide vane control device 31 to operate the opening movable guide vane In in the opening direction, or conversely, in the closing direction when the relative ratio or relative difference is below the specified range. Controls the opening of the movable guide vane.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, when performing water level adjustment control during steady operation, while controlling the opening of the movable guide vane of one step, the opening of the water port of the movable guide vane is changed. Since it is possible to control the opening degree of the movable guide vane of the other stepped portion in accordance with this, it is possible to always select a combination of the above two sets of movable guide pane opening degrees as one that is suitable for hydraulic performance. This means that operation with the best hydraulic performance is always possible during steady operation.

In addition, since it is possible to constantly control the head distribution at each stage, it is possible to avoid operation that is prone to problems such as those mentioned above at the lowest pressure stage where the conditions for cavitation and swirling eddies at the launch exit are relatively the most severe. Adjust the relative ratio or specified range of the relative difference between the water pressure in the intermediate part between the highest pressure stage and the lowest pressure stage and the water pressure on the outlet side of the lowest pressure stage. The above operating conditions can be avoided.

Furthermore, depending on the combination of changes in f between the water ports of the two sets of movable guide vanes, there is a risk that a transient abnormal water pressure increase will occur in the low pressure side step, but according to the present invention, the intermediate water pressure Since it is possible to control the two sets of movable guide vanes while constantly detecting the water pressure, it is possible to prevent an abnormal increase in the water pressure of the low-pressure side step section.

As described above, according to the present invention, it is particularly important in operation! When performing water level adjustment control during operation, it is possible to avoid unstable operating conditions such as opening, noise, cavitation, abnormal water pressure fluctuations, etc., and to always maintain high performance operation. This makes it possible to provide a "water level adjustment section with high performance" for the two-force method.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view of a 7-runcis type two-stage pump-turbine to which the present invention is applied, Fig. 2 is an explanatory diagram of a waterway line including the above-mentioned two-stage pump-turbine, and Figs. 3 and 4 are for redundant operation. The operational control block diagrams, Figures 5 and 6, show the static head difference during steady operation, and the relative ratio between the intermediate water pressure from the highest pressure stage to the lowest pressure stage and the lowest pressure stage exit water pressure. Alternatively, it is a diagram illustrating a prescribed range of relative difference. 2...High pressure stage runner, 3...Low pressure stage runner, 10-
・Return passage, 12-low pressure stage movable guide vane, 15-・
High-pressure stage movable guide vane, 17--middle water pressure detector,
5- Water level adjustment device, 31... Guide vane control device, 27... Lowest pressure stage section outlet side water pressure detection device, 2
9... Silence difference detection device, J... Water pressure difference ratio IIR device. Applicant's agent Kiyoshi Inomata

Claims (1)

[Claims] 1. Each stage from the high pressure stage to the lowest pressure stage is provided with a launch, and each stage is connected by a return passage, and
Changes in the static head difference that acts on the entire multistage hydraulic machine during steady operation in a multistage hydraulic machine that is equipped with movable guide vanes that can change the opening of the water port on the inlet side of each stage of the highest pressure stage and the lowest pressure stage. When performing adjustment control for troublesome operating conditions with respect to tζ, the movable guide vane at the highest pressure section is given a peak command corresponding to the static head difference to open the movable guide vane at the highest pressure section, while the other side is A control command for the water pressure difference between the intermediate water pressure from the highest pressure stage to the lowest pressure stage and the water pressure on the outlet side of the lowest pressure stage is transmitted to the guide vanes of the lowest pressure stage to control the water pressure at the lowest pressure stage. A method for controlling the operation of a multistage hydraulic machine, in which a steady operating state is adjusted and controlled in response to changes in the static head by controlling the opening of a movable guide vane. 2. When the relative ratio or relative difference between the static head difference and the water pressure difference exceeds the specified range, the movable guide vane at the lowest pressure step moves in the closing direction, and conversely, when it goes down, the lowest pressure step movable guide vane The method for controlling the operation of a multi-stage hydraulic machine according to claim 1, characterized in that the adjustment control of the steady operating state is carried out by controlling the opening of the multi-stage hydraulic machine. 3. A runner is provided in each step from the high pressure kill section to the lowest pressure step, and each step is connected by a return passage, and the inlet side of each step of the highest pressure step and the lowest pressure step. In a multi-stage hydraulic machine equipped with a movable guide vane whose opening degree can be changed at the lowest pressure stage, when controlling the operating state in response to changes in the static head that acts on the entire multi-stage hydraulic machine during steady operation, it is necessary to A control command corresponding to the static head difference is transmitted to the movable guide vane of the lowest pressure stage part to control the opening of the movable guide vane of the lowest pressure stage part, while the movable guide vane of the other highest pressure part is transmitted with the control command corresponding to the static head difference. The static head difference is controlled by controlling the opening of the movable guide vane in the highest pressure stage by transmitting a control command for the water pressure difference between the intermediate water pressure leading to the pressure stage and the water pressure at the outlet of the lowest pressure stage. 1. A method for controlling the operation of a multi-stage hydraulic machine, characterized in that the steady state of operation is adjusted and controlled in response to changes in the amount of water. 4. When the relative ratio or relative difference between the static head difference and the water pressure is above the specified range, the movable guide vane at the highest pressure step moves in the opening direction, and conversely, when it falls below, the highest pressure step movable guide vane The method for controlling the operation of a multi-stage hydraulic machine according to claim 3, characterized in that the steady operating state is adjusted and controlled by controlling the opening of the multi-stage hydraulic machine.