A ducted Darrieus-type turbine has been proposed for hydropower utilization of extra-low head less than 2 m.Though the hydro turbine system,in general,might consist of an intake,runner casing section and a draft tube ...A ducted Darrieus-type turbine has been proposed for hydropower utilization of extra-low head less than 2 m.Though the hydro turbine system,in general,might consist of an intake,runner casing section and a draft tube for higher efficiency operation,it was clarified in previous experiment that there was no need of the side-walls of runner casing section and a draft-tube for keeping the efficiency high in the case of duct with an inlet nozzle.This would yield a simplification of the structure of the turbine system.In order to reconfirm this result for large-sized turbine with 560 mm×300 mm duct,instead of small-sized one with 400 mm×200 mm duct,the side-wall effect on turbine performance was experimentally investigated for three-or four-bladed runner.In the present paper,the experimental results are shown with considering flow behaviors in the runner section.展开更多
文摘A ducted Darrieus-type turbine has been proposed for hydropower utilization of extra-low head less than 2 m.Though the hydro turbine system,in general,might consist of an intake,runner casing section and a draft tube for higher efficiency operation,it was clarified in previous experiment that there was no need of the side-walls of runner casing section and a draft-tube for keeping the efficiency high in the case of duct with an inlet nozzle.This would yield a simplification of the structure of the turbine system.In order to reconfirm this result for large-sized turbine with 560 mm×300 mm duct,instead of small-sized one with 400 mm×200 mm duct,the side-wall effect on turbine performance was experimentally investigated for three-or four-bladed runner.In the present paper,the experimental results are shown with considering flow behaviors in the runner section.
