JP2003328919A - Method for repairing existing hydraulic machinery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily grasp water turbine characteristics of an existing hydraulic machinery, to predict how far an actual operation is deviated from a proper operation, and to properly indicate repair of a hydraulic machinery and direction of replace. <P>SOLUTION: Flow passage shape data of an existing hydraulic machinery is sampled by a process flow 101 and based on the sampled data, mesh data for flow analysis is produced by a process flow 102 to effect flow analysis. Based on the result of the flow analysis, an iso efficiency chart of water turbine efficiency is prepared in a plane-form based on a flow rate head and a water turbine output. An operation point indicating the yearly flow state of the existing hydraulic machinery is indicated as spray data on the iso efficiency chart to confirm a deviation between present operation and water wheel characteristics and based on the deviation, a repair policy for the existing hydraulic machinery is decided. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for repairing an existing hydraulic machine.

[0002]

2. Description of the Related Art An example of a conventional hydraulic machine is a Francis type hydraulic machine whose longitudinal section is shown in FIG. As shown in FIG. 7, such a hydraulic machine has a configuration in which a runner 2 in which a rotary shaft 1 is connected to its rotation center is stored in a runner chamber which is a space formed by an upper cover 3 and a lower cover 4. Has become. Here, the runner 2 is configured to hold a plurality of runner vanes 2c between a runner crown 2a and a runner band 2b, which are water flow paths,
The runner crown 2a is connected to the rotary shaft. A plurality of movable guide vanes 5 for adjusting the flow rate of water flowing into the runner chamber and a plurality of fixed stay vanes 6 are provided outside the runner chamber. A casing 7 that surrounds the runner chamber is provided outside the stay vane 6, and a suction pipe 8 is provided below the runner chamber.

In the hydraulic machine having such a structure, the water flowing out from the upper pond (not shown) is guided to the casing 7, passes between the stay vanes 6 and then the guide vanes 5.
The flow rate is adjusted by and flows into the runner chamber.
The water that has flowed into the runner chamber flows between the runner crown 2a and the runner band 2b of the runner 2 and performs work while passing between the plurality of runner vanes 2c provided here to rotate with the runner 2. Rotate shaft 1 and. Rotating shaft 1
A generator (not shown) is connected to, and the rotation of the rotating shaft 1 is transmitted to generate electric power. And
The water that has caused the runner 2 to perform work flows out from the lower part of the runner chamber, flows into the suction pipe 8, and is guided from there to a lower pond (not shown).

At the stage of planning the installation of such a hydraulic machine, an operating pattern is assumed based on the required output, natural conditions such as location, and each device is designed in a frequently operating state. In many cases. However, since a hydraulic machine is generally operated for a long period of several decades, the operation pattern initially assumed may differ from the actual operation pattern during such a long-term operation. However, the characteristics of hydraulic machinery are optimally designed when operating in the operating pattern assumed at the beginning of the plan.
In such cases, the hydraulic machine is forced to operate non-optimally. As described above, when the originally assumed operation pattern and the actual operation pattern differ, in order to judge how much the actual operation pattern deviates, the turbine characteristic, which is the efficiency characteristic of the hydraulic machine, is used. It is necessary to ask for it, and the performance of the hydraulic machine can be confirmed only by finding the characteristics of the turbine.

A method for obtaining the turbine characteristic of the existing hydraulic machine will be described with reference to FIG. Generally, in order to obtain the hydraulic turbine characteristics of a hydraulic machine, a field efficiency test is conducted by using an actual hydraulic machine to test how much of the energy of water can be obtained as work for various flow rates and effective heads. And a method of making a model turbine with a similar shape to an actual hydraulic machine and confirming the characteristics by a similar model turbine test. In general, the on-site efficiency test is often performed as a confirmation test before and after the replacement of the runner (replacement) with a hydraulic machine immediately after new construction. When conducting an on-site efficiency test, it is necessary to measure data such as flow rate, effective head, generated output, etc. Therefore, it is necessary to first consider what measurement method to use for each of these. Especially for detecting the flow rate, it is necessary to use a method such as an ultrasonic method or a pressure time method, and a measuring device for this purpose is attached to the hydraulic machine. After the measurement method is decided, on-site efficiency tests are conducted.However, since there are few hydraulic machines installed at points where the effective head during operation is almost constant, generally, the effective head is changed variously and the effective head is changed several times. An efficiency test will be conducted and the results will confirm the characteristics of the existing hydraulic machine.

[0006]

However, even when conducting an on-site efficiency test in order to obtain the turbine characteristics of an existing hydraulic machine, complicated work such as mounting a measuring device on the hydraulic machine several decades after its installation occurs. I often do it. Whether the effective head can be changed before and after the on-site efficiency test can be changed depending on the location condition of the point where the hydraulic machine is installed. Generally, the effective head can be changed before and after the on-site efficiency test. Things are rare. Therefore, when conducting a local efficiency test for various effective heads, especially for hydraulic machines installed at points where the fluctuation of the effective head is large, the local efficiency test will be carried out again when the head changes. It sometimes took a long time to understand the characteristics of the existing hydraulic machine. There is also a method of manufacturing a model water turbine similar to an actual machine and conducting a similar model water turbine test to confirm the characteristics, but there is a problem that it costs a manufacturing cost and a test cost of the model.

As described above, in order to confirm the performance of the existing hydraulic machine by grasping the characteristics of the hydraulic turbine, a field efficiency test or a similar model turbine test may be carried out. It often requires labor and effort. However, even if it takes time and effort to perform these, it is only possible to confirm the performance of the existing hydraulic machine, and based on the results of the performance confirmation, the existing hydraulic machine will be repaired, the runners will be replaced (replaced), or the hydraulic machine will be replaced. An efficient hydraulic machine can be obtained only by taking measures such as batch updating.

For this reason, when the initially assumed operation pattern and the actual operation pattern are different, the existing hydraulic machine is refurbished or the runner is replaced so that the operation pattern is suitable for the actual operation pattern. Since it is most important to take measures such as taking measures, it is rare to check the performance of the existing hydraulic machinery with great effort and cost as described above just to determine these measures. At present, almost no local efficiency tests or similar model turbine tests are performed on hydraulic machinery.

The present invention has been made in view of these points, and it is possible to easily grasp the turbine characteristics of an existing hydraulic machine, evaluate how the actual operation deviates from the proper operation, and Its purpose is to properly indicate the direction of repairs and replacements.

[0010]

In order to solve the above-mentioned problems, a method for rehabilitating an existing hydraulic machine according to claim 1 of the present invention is to draw a flow path shape of an existing hydraulic machine such as a water turbine, a pump or the like. An analysis model that is quantified by physical measurement is created, and a flow analysis is performed using the analysis model with various operating states of the existing hydraulic machine as analysis conditions, and the existing hydraulic machine obtained from the result obtained by the flow analysis. And the annual flow regime showing the actual operation of the existing hydraulic machine are compared, and the flow path shape of the existing hydraulic machine is determined from the annual flow regime by the result of comparison between the hydraulic turbine property and the annual flow regime. It is characterized in that it is changed so as to improve the efficiency of the water turbine at the driving point where the driving frequency is high. By using this method, it is possible to confirm the performance of the existing hydraulic machine relatively easily without conducting a local efficiency test or a similar model turbine test, and make sure that the existing hydraulic machine has characteristics suitable for actual operation. A policy for renovation can be appropriately set.

Further, in the method for rehabilitating an existing hydraulic machine according to claim 2 of the present invention, in addition to claim 1, the turbine characteristic is that the effective head and the flow rate, or the effective head and the turbine output are on a plane. It is represented as an efficiency diagram, and the annual flow regime is characterized in that an annual operating point of the existing hydraulic machine is represented on the plane as a scatter diagram. By doing this,
Turbine characteristics of existing hydraulic machinery obtained by flow analysis,
It is possible to easily compare with the annual flow condition showing the actual operation of the existing hydraulic machine, and it is possible to easily judge whether the turbine characteristics of the existing hydraulic machine are suitable for the actual operation.

Further, a method for rehabilitating an existing hydraulic machine according to claim 3 of the present invention is the same as claim 1 or claim 2,
The leakage loss, disc friction loss, friction loss, and eddy loss, which are the losses generated in the flow path, are compared between the operating point with high operating frequency determined by the annual flow regime and the operating point with high turbine efficiency determined by flow analysis. However, the flow path shape of the existing hydraulic machine is changed so as to reduce the loss with the smallest ratio of the loss at the operating point with high turbine efficiency to the loss at the operating point with high operating frequency. . In this way, by comparing each loss that occurs in the flow path at the operating point with high operation frequency and the operating point with high efficiency, which loss can be reduced to improve the efficiency at the operating point with high operation frequency. Therefore, it becomes possible to properly rehabilitate the existing hydraulic machinery.

Further, in the method for rehabilitating an existing hydraulic machine according to claim 4 of the present invention, in addition to claim 3, the existing hydraulic machine is a Francis type hydraulic machine, and when the eddy loss is reduced, the existing hydraulic machine is reduced. Among the runner vanes of the machine, it is characterized by changing the outlet opening and the outlet blade angle.

Further, in the method for rehabilitating an existing hydraulic machine according to claim 5 of the present invention, in addition to any one of claims 1 to 4, an analytical model in the case of changing the flow path shape is created. Then, based on this, the flow analysis is performed again to confirm the performance, and then the flow path shape is changed.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a flow chart showing a first embodiment of the present invention. In the present embodiment, as the processing flow 101, first, the flow path shape data of the existing hydraulic machine is sampled. To create this data, use the drawings of the existing hydraulic machine or measure the flow path shape of the existing hydraulic machine. For example, in the case of the conventional hydraulic machine shown in FIG. 7, data regarding flow path shapes such as the runner 2, the runner chamber formed by the upper cover 3 and the lower cover 4, the guide vanes 5, the casing 7, and the suction pipe 8 is provided. Collect.

When the collection of the flow path shape data of the existing hydraulic machine is completed in the processing flow 101, next, based on the flow path shape data collected in the processing flow 102, mesh data for flow analysis ( Create an analysis model).

Next, in process flow 103, analysis conditions in a plurality of operating states corresponding to changes in effective head and flow rate are selected from the current operation pattern of the existing hydraulic machine, and the analysis conditions for each are also selected. And perform flow analysis.
Here, in selecting the analysis conditions, first, the processing flow 1
The effective head H is selected at 03a. Where the effective head H
When selecting, the effective head H that is frequently operated should be selected based on the operation pattern of the existing hydraulic machine, but it is necessary to select the analysis conditions corresponding to a plurality of operating states and perform the flow analysis. Therefore, it may be appropriately selected from the maximum head, the minimum head, the reference head, and the like. Then, in the processing flow 103b, the flow rate Q in the effective head H selected in the processing flow 103a is selected. Here, in the process flow 103b, the flow rate Q is selected, but the output of the hydraulic machine (turbine output P) may be selected instead of the flow rate. Also here, in the same manner as the processing flow 103a, in selecting the flow rate Q and the turbine output P, the flow rate Q and the turbine output P that are frequently operated may be selected based on the operation pattern of the existing hydraulic machine.

When the analysis condition is selected in this manner, the process flow 103c is advanced to the process flow 103.
Flow analysis is performed under the analysis conditions (effective head H, flow rate Q) selected in a and 103b. As a result, the turbine output P, the loss in each flow path of the hydraulic machine, and the cavitation performance of the hydraulic machine are calculated. Then, the processing flow 10
3d, the turbine efficiency η, which is the efficiency of the hydraulic machine under the analysis conditions selected in the processing flows 103a and 103b, is calculated based on the loss of each flow path obtained in the processing flow 103c and the cavitation performance of the hydraulic machine. Calculate. When the turbine output P is selected and the flow analysis is performed in the processing flow 103b, the flow rate Q and the loss in each flow path of the hydraulic machine are calculated in the processing flow 103c. The turbine efficiency η under the analysis conditions selected in the processing flows 103a and 103b will be calculated. Furthermore, the processing flow 10
It is also possible to proceed to 3e and calculate the power generation efficiency η _E and the power generation output P _E by taking the generator efficiency into consideration in the turbine efficiency η calculated in the processing flow 103d. When calculating these,
Although the generator efficiency under the analysis conditions selected in the processing flows 103a and 103b is required, if it is unknown, it is preferable to use the average generator efficiency as the representative value. Through the processing up to this point, the turbine efficiency η and the power generation efficiency η _E when the initially selected effective head H and flow rate Q (or turbine output P) are used as the analysis conditions are obtained. Then, returning to the processing flow 103b, another flow rate Q (or the turbine output P) is selected and the flow analysis is performed under the analysis conditions, and similarly, the turbine efficiency η and the power generation efficiency η _E are calculated. In this way, the flow analysis is performed a plurality of times with the effective head H selected in the processing flow 103a as the analysis condition. Further processing flow 103a
Returning to, another effective head H is selected and the flow analysis is performed in the same manner. By these processes, the turbine efficiency η and the power generation efficiency η _{E under} the analysis conditions corresponding to the plurality of operating states of the existing hydraulic machine are calculated. In the present embodiment, the flow analysis is carried out under a plurality of analysis conditions, but the number of times and the analysis conditions are selected only as necessary and sufficient as possible to create a water turbine characteristic diagram and an efficiency curve diagram, which will be described later. Be prepared to be able to confirm the performance of the hydraulic machine with a certain degree of accuracy.

When the turbine efficiency, the power generation efficiency, etc. corresponding to a plurality of analysis conditions are calculated in the processing flow 103, the process proceeds to the processing flow 104, and the analysis results are summarized to create a turbine characteristic diagram as shown in FIG. FIG. 2 is a hydraulic turbine characteristic diagram showing the contour line of the hydraulic turbine efficiency η with the effective head H as the horizontal axis and the flow rate Q as the vertical axis. In addition, the maximum drop H _max of the existing hydraulic machine and the reference drop H
By drawing _nor and the minimum head H _min , it can be seen that the inside surrounded by these is the operating range of this hydraulic machine. Further, in the present embodiment, the hydraulic turbine characteristic diagram obtained by the flow analysis is superposed with the annual flow condition showing the operation of the existing hydraulic machine for one year. This annual flow condition is data that shows as a trend what kind of operating points and how many operating points an existing hydraulic machine is operating in one year.
The effective head and the flow rate when the operation is performed can be expressed as a scatter diagram shown on a plane of the effective head-flow rate by a circle, for example. Then, by superimposing the annual flow condition showing the operation pattern of the existing hydraulic machine on the turbine characteristic diagram obtained by the flow analysis, how much the operation pattern of the existing hydraulic machine deviates from the proper one. You can easily and accurately know what is happening.

That is, in the present embodiment, the turbine characteristics obtained by performing a flow analysis using the flow path shape of the existing hydraulic machine are compared with the annual flow condition which is the actual operation of this hydraulic machine. Since it is possible to easily know the deviation of the operation pattern of the existing hydraulic machine, it is possible to easily and accurately confirm the performance of the existing hydraulic machine without performing a local efficiency test or a similar model turbine test.

It is also possible to perform more detailed performance confirmation based on the characteristic diagram of the water turbine shown in FIG. FIG. 3 shows FIG.
Based on the result of the flow analysis performed in the processing flow 103 shown in and the annual flow condition of the existing hydraulic machine, the flow rate Q is plotted on the horizontal axis,
FIG. 7 is an efficiency curve diagram showing the turbine efficiency η when the turbine efficiency η is plotted on the vertical axis and the effective head H is constant. That is, FIG. 3 is an efficiency curve diagram when the effective head H is constant in FIG. 2, and conceptually shows a cross section obtained by cutting the equiefficiency line in FIG. 2 at a certain effective head H. Here, by setting the value of the effective head H that is constant to the effective head H that is frequently used in the annual flow regime shown in FIG. 2, it is possible to perform more accurate comparison with the annual flow regime. Here, for convenience of explanation, the circles indicating the annual flow condition show only two typical points A and B which are frequently operated.

In FIG. 3 as described above, the efficiencies at points having the highest operating frequency are compared. Point A shown in this figure can be determined to be an appropriate characteristic when the point with the highest operating frequency is close to the maximum efficiency point, but in the case of an operating point with low efficiency such as point B that is far from the maximum efficiency point. Can be determined not to be an appropriate property. As shown in FIG. 3, when it is not possible to determine that the existing hydraulic machine has proper characteristics, the point B with a large operating frequency is the operating point with a low efficiency in the effective head H with a large operating frequency in the annual flow regime. Therefore, it is necessary to take measures such as repair and replacement of hydraulic machinery. The method of determining the policy for this is shown below.

Generally, the losses that occur in the flow path of a hydraulic machine are
It consists of leakage loss, disc friction loss, friction loss, and eddy loss. Among them, the leakage loss is that in the hydraulic machine shown in FIG. 7, the water guided from the casing 7 does not flow into the runner 2 and, for example, the runner chamber and the runner 2 which are composed of the upper cover 3 and the lower cover 4. Is a loss generated by being guided to the suction pipe 8 through a gap between the runner crown 2a and the runner crown 2a when the runner 2 rotates in the runner chamber and water. It is a loss caused by friction. The friction loss is a sum of the loss due to the surface roughness of each flow path and the loss caused by the separation of the flow in each flow path, and the eddy loss is guided from the inside of the runner 2 to the suction pipe 8. This is a loss caused by the generated water becoming a flow having a swirl velocity component inside the suction pipe 8.

In order to reduce these losses by repairing the hydraulic machine, the following methods are generally adopted. In order to reduce the leakage loss, for example, the seal shape of the runner 2 which is the rotating part and the design of the seals of the upper cover 3 and the lower cover 4 which are the stationary parts may be changed. Runner 2 to reduce
It is effective to take measures such as reducing the outer peripheral side areas of the runner crown 2a and the runner band 2b. Further, the friction loss is a sum of the loss caused by the surface roughness of each flow path and the loss caused by the separation of the flow caused by the mismatch of the inflow angle of water into the runner 2, so that the runner vane 2c and the guide Vane 5,
Further, the loss can be reduced by changing the surface roughness and the shape of the elements constituting the flow path such as the stay vanes 6. Since the swirling flow generated downstream of the runner 2 is greatly involved in the eddy loss, it is an effective measure to reduce the loss that the runner vane 2c is mainly changed in design on the runner 2 outlet side.

In the present embodiment, the flow analysis of the existing hydraulic machine is performed, and the processing flow 103d shown in FIG. 1 is performed.
Since the turbine output P, the loss in each flow path of the hydraulic machine, and the cavitation performance of the hydraulic machine are calculated, the leakage loss, the disc friction loss, the friction loss, and the eddy loss are respectively included in the total. You can easily find out what percentage it is. FIG. 4 shows the results of obtaining these, and shows the efficiency curve shown in FIG. 3 for each loss of leakage loss, disc friction loss, friction loss, and eddy loss. Here, in order to compare the efficiencies of the turbines, the vertical axis of FIG. 4 is the turbine efficiency η.

As described above, the operation at the operating point B in FIG. 3 is lower in efficiency than the operation at the operating point A close to the maximum efficiency point in this head. Then, in the present embodiment, as shown in FIG. 4, the leakage loss, the disk friction loss, the friction loss, and the eddy loss at the operating point B where the efficiency is low and the maximum efficiency point in this effective head are determined. A comparison is made with each loss at the near operating point A. For example, comparing the respective losses at the operating point B and the operating point A shown in FIG. 4, the reduction ratio of the eddy loss is the largest. Therefore, in order to improve the efficiency at the operating point B, it is necessary to reduce the eddy loss. It turns out to be effective.

In this way, in the present embodiment, attention is paid to each loss calculated as a result of the flow analysis, and as shown in the example of FIG. 4, for example, a comparison is made with a highly efficient operating point at a high head of operating frequency. By doing so, it is determined which loss causes the efficiency of the existing machine to be low. Then, it is possible to determine which part of the existing machine is badly designed and clarify the direction of improvement. That is, comparing the results of the flow analysis of the existing hydraulic machine with the actual annual flow conditions, if the existing hydraulic machine is operated at a low efficiency operating point frequently, the operating point with a high operating frequency and the efficiency Compare each loss at higher operating points. Then, by paying attention to the loss in which the ratio of the loss at the operating point having high efficiency to the loss at the operating point having high operating frequency is the smallest, it is possible to easily determine which part of the design change is effective. Then, based on this judgment, by improving the design changeable part within the range allowed for the existing hydraulic machine, it is possible to approach the proper characteristics. As described above, the present embodiment performs the flow analysis based on the flow path shape of the existing hydraulic machine,
This result will be compared with the annual flow regime showing the actual operation of the existing hydraulic machinery. Then, as a result of this comparison, when the existing hydraulic machine has a high operation frequency at an inefficient operating point, it is possible to easily determine a policy of changing the flow channel shape or the like so as to improve the efficiency at this operating point. . Next, regarding such a specific method for changing the design of a hydraulic machine,
An example of application to the Francis type hydraulic machine, which is the conventional hydraulic machine shown in FIG. 7, is shown.

FIG. 5 shows an AA cross section of the Francis type hydraulic machine which is the conventional hydraulic machine shown in FIG. 7, and shows a cross section of the runner vane 2c along the streamline of the water flowing inside the runner 2. FIG. In this figure, an inlet virtual curve lin is a curve _{in which} the inlet side end portions of a plurality of runner vanes 2c, that is, the front edges of the runner vanes 2c are smoothly connected in the AA cross section of FIG. Similarly, the virtual exit curve l _out is a curve in which the end of the runner vane 2c on the exit side in the section AA in FIG. 7, that is, the trailing edge of the runner vane 2c is smoothly connected.

In the present embodiment, the outlet opening D, which is the distance between the adjacent runner vanes 2c at the trailing edge of the runner vane 2c, and the trailing edge line and the outlet indicating the outflow direction of water at the trailing edge of the runner vane 2c. Virtual curve l
The value of the blade outlet angle θ _out , which is the angle formed by _out , is modified, and the shape of the runner vane 2c is changed from the shape shown by the solid line to the shape shown by the dotted line. Here, this example shows an example in which the outlet opening D and the blade outlet angle θ _out are modified as a measure for improving the turbine efficiency at the operating point B shown in FIG. The eddy loss is reduced by reducing the blade outlet angle θ _out . Further, when the shape of the outlet side of the runner vanes 2c is changed, the circulation value of the flow around the runner vanes 2c and the pressure distribution on the surface of the runner vanes 2c also change, so that not only eddy loss but also friction loss can be reduced. In some cases

In particular, when the operation pattern of the existing Francis type hydraulic machine changes as shown in this embodiment,
Partial load operation, that is, operation at an operating point where the flow rate is smaller than the maximum efficiency point at each head as shown in FIG. 2, often increases. And in such a case, runner 2
If the eddy loss is reduced by changing the design, especially by changing the shape of the runner vane 2c on the outlet side, it is possible to obtain the turbine characteristic suitable for the actual operation pattern. In order to reduce the eddy loss, as described above, the outlet opening degree D of the runner vane 2c and the blade outlet angle θ _out are corrected, so that the turbine characteristics can be partially changed without making other large changes such as other static flow paths. It is possible to change to a turbine characteristic suitable for load operation.

Further, according to the present embodiment, after the method of design change or refurbishment of the hydraulic machine is determined in this manner, the turbine characteristics can be confirmed again using the changed flow path shape. It is possible. Even in this case, if the same processing as the processing flow shown in FIG. 1 is performed, it is possible to easily confirm the characteristics of the changed hydraulic machine and compare it with the annual flow condition. FIG. 6 shows an example of comparison of monthly generated electric energy by using monthly operating point data regarding the annual flow condition of the existing hydraulic machine. Here, this example exemplifies a case where the hydraulic machine described in FIGS. 2 to 5 is refurbished, and the existing hydraulic machine and the hydraulic machine after changing the turbine characteristics as shown in FIG. We are comparing the amount of electricity generated by machine with each month.

That is, in the example shown in FIG. 6, the annual flow regime data obtained by adding the time information of the operation at each operating point to the data of the operating point determined by the effective head H and the flow rate Q. By using it, it is an estimate of the amount of electric power generated annually. In particular, in the present embodiment, by graphing these for each month, it is possible to predict how much power generation can be expected at what time of the year by performing repairs and changing the characteristics of the water turbine. It is possible to grasp the information, and it is possible to easily evaluate the economic effect of retrofitting the existing hydraulic machinery.

In this example, as shown in FIG. 5, the outlet opening degree D of the runner vane 2c and the blade outlet angle θ _out are modified to improve the efficiency during partial load operation. Then, as shown in FIG. 6, this measure improves the turbine efficiency even if the flow rate Q is reduced and the partial load operation is performed. Therefore, the generated power amount in winter when the generated power amount is decreased is increased to increase the It can be seen that the amount of generated power can be increased. Then, by making these comparisons not only in the repair shown in FIG. 5 but also in the case where the entire hydraulic machine is renewed and in various other cases, it is effective to perform what kind of repair to the existing hydraulic machine. You can easily know if there is. Therefore, by carrying out an actual repair based on these, even if the operation pattern of the existing hydraulic machine is different from the actual operation pattern, it becomes possible to repair the hydraulic machine with appropriate characteristics.

As described in detail above, according to the method for repairing an existing hydraulic machine of the present invention, the flow path shape data of the existing hydraulic machine is sampled and digitized to create an analytical model, which is used for various operating points. By obtaining the current turbine characteristics by performing flow analysis and comparing it with the annual flow condition that shows the actual operation of the existing hydraulic machine, it is possible to easily understand how much the existing hydraulic machine deviates from the appropriate characteristics. However, it will be possible to accurately indicate the direction such as the rehabilitation of the existing hydraulic machinery to improve the operation efficiency.

[Brief description of drawings]

FIG. 1 is a flow chart diagram of a first embodiment according to the present invention.

FIG. 2 is a characteristic diagram of a water turbine obtained by flow analysis.

FIG. 3 is an efficiency curve diagram of the hydraulic machine obtained by the flow analysis.

FIG. 4 is an efficiency curve diagram of the hydraulic machine obtained by the flow analysis.

FIG. 5 is an explanatory view of a shape before and after changing a runner vane according to the present invention.

FIG. 6 is a comparison diagram of annual electric power generation before and after the repair of the hydraulic machine according to the present invention.

FIG. 7 is a vertical cross-sectional view of a Francis type hydraulic machine which is a conventional hydraulic machine.

FIG. 8 is an explanatory diagram for obtaining characteristics of a conventional existing water turbine.

[Explanation of symbols]

1 rotation axis 2 runners 3 Top cover 4 Lower cover 5 guide vanes 6 Stay vanes 7 casing 8 Suction tube

Claims (5)

[Claims] 1. An analytical model in which a flow path shape of an existing hydraulic machine such as a water turbine or a pump is quantified by drawing or actual measurement, and the analytical model is used as various operating conditions of the existing hydraulic machine as analysis conditions. The flow characteristics of the existing hydraulic machine obtained from the results obtained by the flow analysis are compared with the annual flow conditions showing the actual operation of the existing hydraulic machine. A method for repairing an existing hydraulic machine, characterized in that the shape of the flow path of the existing hydraulic machine is changed so as to improve the turbine efficiency at an operating point with a high operating frequency determined from the annual flow regime, according to the result of comparison with the existing hydraulic machine. 2. The method for rehabilitating an existing hydraulic machine according to claim 1, wherein the turbine characteristic is represented as an iso-efficiency map on a plane having the effective head and the flow rate, or the effective head and the turbine output as an axis, and the annual flow rate. The situation is a method of rehabilitating an existing hydraulic machine, characterized in that annual operating points of the existing hydraulic machine are represented on the plane as a scatter diagram. 3. The method for rehabilitating an existing hydraulic machine according to claim 1 or 2, wherein a flow path is provided between an operating point with a high operating frequency determined from the annual flow regime and an operating point with a high turbine efficiency determined by flow analysis. Leakage loss, which is the loss caused by
Disc friction loss, friction loss, and eddy loss are respectively compared, and the existing hydraulic power is reduced so as to reduce the loss with the smallest ratio of the loss at the operating point with high turbine efficiency to the loss at the operating point with high operating frequency. A method for rehabilitating an existing hydraulic machine, characterized by changing the flow path shape of the machine. 4. The method for repairing an existing hydraulic machine according to claim 3, wherein the existing hydraulic machine is a Francis type hydraulic machine, and when the eddy loss is reduced, the outlet opening of the runner vanes of the existing hydraulic machine is opened. Degree and exit blade angle are changed, the existing hydraulic machine rehabilitation method characterized by the above-mentioned. 5. In the method for rehabilitating an existing hydraulic machine according to any one of claims 1 to 5, an analysis model is created when the shape of the flow path is changed, and the flow analysis is performed again based on this. A method for rehabilitating an existing hydraulic machine, characterized in that the shape of the flow path is changed after the performance has been confirmed.