TY - JOUR ID - 1534 TI - Safe control of air cushion surge chambers in hydropower systems JO - Scientia Iranica JA - SCI LA - en SN - 1026-3098 AU - Jianfeng, An AU - Jian, Zhang AU - Hazrati, A. AD - College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, P.O. Box. 210098, China Y1 - 2013 PY - 2013 VL - 20 IS - 6 SP - 1605 EP - 1611 KW - Air cushion surge chamber KW - Control mode KW - Hydropower system KW - Air compressor KW - Exhaust valve KW - Hydraulic transients DO - N2 - This paper presents an effective theory for safe controlof air cushion surge chambers (ACSCs) in hydropower systems. On the basis of the emergency pressures and heights of air in chambers, the acceptable limits of the monitoring parameters for three kinds of control modes are derived theoretically to control the air compressor. The prerequisites for each control mode are determined with considering the air leakage and solution. By analyzing these prerequisites, the selection criteria are established to determine the appropriate control mode for the practical hydropower system with the ACSC. According to the presented control scheme, the air compressor need not be actuated for any variation of the air temperature, and the operating conditions of the hydropower system need not be considered for safe control of ACSCs. Those are favorable for safety and economy of the hydropower plant. To detail and validate the derived limits and selection criteria for different control modes, the safe control theory is applied to the practical hydropower plant, and the graphic analysis is conducted on the basis of the perfect gas law and the relationship of the initial steady-state pressure and height of the enclosed air in chambers. UR - https://scientiairanica.sharif.edu/article_1534.html L1 - https://scientiairanica.sharif.edu/article_1534_c19a68aef713374f9e21624f77b75462.pdf ER -