CAM CORRELATION ANALYSIS USING ACOUSTIC DISCHARGE MEASUREMENT
The low head hydro power plant in Wettingen, Switzerland, is in operation since 1933 and no effective cam optimization has been carried out up to now. The goal of the measuring campaign was to provide data enabling an economic study for a retrofit and upgrade project of the plant and the measurement of the efficiency improvement of turbines after refurbishment. The contribution discusses cam tests using the acoustic transit time method in the intake for discharge measurements. A cam correlation analysis and an efficiency test of the installed Kaplan turbines were performed as a first measurement campaign showing the actual status. While one turbine operated at optimum cam, the other two turbines operated off-cam. After rehabilitation works, based on the recommendations of the first measurements, a second measurement campaign was performed. The results showed the expected efficiency increase due to overhaul of the regulating mechanics (connection between the piston stroke in the machine hall and the regulating ring / guide vane stem at the turbine) of the governor. With the set of data from the second measurement campaign an optimization study for the operation of the three Kaplan units were conducted. Especially the transition zone from one to two and from two to three machine operation could be optimized due to the knowledge of the individual efficiency curves.
DISCHARGE MEASUREMENTS AT LA RANCE TIDAL POWER PLANT USING CURRENT METERS METHOD
La Rance was the first tidal power plant worldwide with a capacity of 240 MW supplied by 24 bulb units working in both flow directions. Many tests had been undertaken in laboratory and on the prototype of Saint-Malo, but no real commissioning tests had been carried out until now. Measuring discharge at La Rance is indeed complex because of a very low and changing head from 2 m to 11 m depending on the tides, large gate bays of 8.7 m on 8.8 m, and high flow rate variations from 75 m 3 /s to 280 m 3 /s. It was decided to use current meters on a moving frame in the bulkhead slot for flow rate measurement. Further challenge was to maintain an almost constant head of 4 m during data acquisition. Full exploration of the velocity field was completed in both directions in 6 vertical positions. Additionally cam tests were performed, using index measurement with the frame in the middle position.
Introduction and experience with the primary mail services based on their names for students
Kyushu University provided mail service based on student IDs such as "1AB10123X" to the university students for many years. Using this model, we had problems communicating with the students who graduated from the University and enrolled in the graduate school. The students received new mail addresses based on their new student IDs such as "2AB12789Y". Faculty members were forced to change the student mail addresses in the mailing lists and in their mail client address book. Furthermore, students were forced to notify the e-mail address change to all of their existing contacts. We introduced a new mail system to provide addresses based on the student name, as well as student ID in April 2011. The new naming convention uses the following format: lastname.firstname.999 where 999 is a random number of 3 digits. Students can select some combination patterns of their first and last names for Japanese. We also consider the middle names for foreign students. In the system implementation, we did not have the formal information of alphabetical names for students. We generated alphabetical names from Japanese Katakana names. It is not easy for us to get the appropriate name in this manner. We implemented a confirmation stage of the alphabetical name at first use, and then students can select their mail addresses for their convenience. We paid much attention to the user interface in the system. Since April 2011, the number of users who use the mail address based on their own name has been increasing gradually. This paper will detail the usage status of the new system.