Application Of Air Cushion Surge Chamber In China

The concept of air cushion surge chamber was put forward by Norwegian engineer named L?Rathe, and succeeded in using at first of Driva power station project on 1973. The air cushion surge chamber was used extensively in Norway from Driva power station because of its multiplex advantages, such as flexibility of layout, convenience of construction, being economic and environmentally friendly, safety and reliability, etc. The air cushion surge chamber was studied in our country from the eighties of the 20th century, and was used actually in Zhi Yili power station of Huaneng group and Xiao tiandu power station of Huaneng group after 2002. This text, starts from the design idea of air cushion surge chamber, refers especially to the experience and lessons of design, construction and operation in Norway where the technique of air cushion surge chamber was applied most successfully and extensively, relies on Xiao tiandu power station of hua neng group, studies the key technique in the construction of air cushion surge chamber. Meanwhile, author still hopes to promote the application of technique of air cushion surge chamber in China. (1)It is possible to build air cushion surge chamber in the alpine gorge areas of the Midwest of our country where the geological condition is fine, the ground stress is big, the groudwater level is relatively high. When the way of developing of long tunnel and low lock gate is adopted in these areas, the project will face these problems, such as that the rock mass near power-building is lower than reservoir water height, but the pressure head of seepage tunnel is higher than ground surface, that it is difficult or impossible to build the construction road to upper part of surge chamber because the hillslope near power-building is too steep, that it is difficult to excavate surge chamber because the geological condition of hillslope surface back power-building is too bad, then,the possibility of choosing air cushion surge chamber can be considered. (2)The flexible layout of diversion system is the merit of air cushion surge chamber, but the layout of air cushion surge chamber is key to design. (3)Under the disadvantage situation of geohydrologic condition, the sealing of surge chamber is another key technique in the construction of air cushion surge chamber. Such as: grouting for surge chamber, setting water curtain hole, etc, such measures can solve effectively the sealing of surge chamber. (4)For the air cushion surge chamber, the construction is simple and convenient, the environmental protection benefit is obvious, the economic benefit is remarkable. (5)With corresponding condition, the project should use extensively air cushion surge chamber in our country. Though the air cushion surge chamber of Yi li power station presented some accidents in the course of building, the reason had been found through analysis, the corresponding measure had been taken to deal with accidents at present. The accidents that appeared in Zhi Yili power station should not become hindrance for the popularity of air cushion surge chamber used in our country. After all, the air cushion surge chamber is a new technique in our country, we have not abundant experience among design, construction and operation in our country, therefore, the surveying, design, construction and running of air cushion surge chamber should be prudent in order to avoid the emergence of accidents.