Use of advanced field measurement method can detec -

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Use of advanced field measurement method can detect hydropower state examination

Increase. There is going to introduce a special low-head turbine is the Francis units. It was the main rotor blade fatigue crack damage. Strain gauge measurements for different operating conditions are static and dynamic pressure of a reliable value [2]. The Norwegian company by the general water as part of research work and to improve their basic mechanical design. We will apply this method in low,[link widoczny dla zalogowanych], medium and high water head Francis units, low-head of the Pelton turbine unit and pump on the unit. [3】 strain gauges were installed in the two-blade rotor pressure surface and suction surface of the crown. Strain gage installation position shown in Figure 9. Because a limited number of measurement channels in each location can only use a strain gauge,[link widoczny dla zalogowanych], which means that only one direction on the measured stress. In order to get bi-directional stress (Mohr circle),[link widoczny dla zalogowanych], you must use the three strain gauges [4】. FE analysis, strain gauge measuring the direction of maximum principal stress direction is similar. Figure 9, the suction surface of runner blade position of strain gauge strain gauge layout (sealed) and do not make any direct phase improved runner blade. To prevent the flow strength (average flow rate of close to l30ft / s) of the interference, strain gauges and wires are sealed with a thin layer of waterproof epoxy. Norconsult is currently used in the installation of fixed wheel battery-powered waterproof sealed 8-channel data recorder, as shown in Figure 10. Waterproof connector through the strain gauge and data logger connected. Data logger can record eight strain gauge data, and these data are stored in internal memory where it is the sampling rate per channel of 1200 samples / sec. When the load and speed changes,[link widoczny dla zalogowanych], the work in 65 minutes. Another data logger used to determine the position of guide vanes the same time. Fixed blade near the hub of the measurement results obtained after the edge shown in Figure 11. Figure 11 left shows the full load range of the maximum principal stress (peak value). For high stress under partial load amplitude, the runner blades are exposed, 30% of the maximum load in place. Figure ll right in the analysis of stress in all the load, from 0 to l00% frequency change under the law. In order to better demonstrate the results to the addition to a smaller stress amplitude. Graphic shows the maximum stress amplitude in frequency was 2.5Hz and 38Hz Department. 20% and 35% 38Hz between stress amplitude at a large number of the hour circle caused by the high stress fatigue loading. A large number of 121Hydropower2004 flow analysis [5】 When the input to the fatigue analysis of data in the measurement of some description. Based on these results, the factory should be restricted units in the part load operation method to reduce the likelihood of fatigue failure. Figure 10 moving inside the wheel hub and the pressure sensor data logger installation

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