In the context of increasing electricity production by intermittent New and Renewable Energy (NRE) sources such as wind and solar, hydropower will play a crucial role in the power network by providing grid frequency control and balancing between electricity production and consumption. This, however, requires flexible operations of the hydropower units, notably the extension of their operating range to off-design conditions, where they are subject to dramatic flow instabilities putting at risk the system stability. Francis turbine, that represent 60% of the total hydro capacity installed worlwilde, may experience flow instabilities in their draft tube at off-design conditionsputting at risk the electro-mechanical system:<\/p>\n
\u30fbSelf-oscillations of a cavitation vortexat full load, inducing severe pressure pulsations;\uf0b7<\/p>\n
\u30fbPrecession of a helical vortex at part load, inducing a pressure-excitation source for the whole hydraulic system and potentially leading to resonance.<\/p>\n
Based on the new understanding ofthe physical mechanisms of such flow instabilities obtained during the previous financial year, this researchplanproposes toimplement new optimized draft tube designs and flow control methodsto mitigate draft tube flow instabilities. An approach based on both fundamental and applied research is proposed. The fundamental physics of the turbine flow will be investigated on simplified test-cases and the new gathered methodologies for the optimization of turbine design and flow control will be finally applied to an actualFrancis turbine model, and then to industrial projects in collaboration with Japanese hydro equipment manufacturers and hydropower utilities. This will represent an important milestone towards the safe operating range extension and flexible operation of hydropower units to fulfill with the new requirements of the electrical power network.<\/p>\n","protected":false},"excerpt":{"rendered":"
In the context of increasing electricity production by intermittent New and Renewable Energy (NRE) sources suc […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[109],"tags":[],"class_list":["post-5468","post","type-post","status-publish","format-standard","hentry","category-prj","lang-ja","sr-technology"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/posts\/5468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/comments?post=5468"}],"version-history":[{"count":3,"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/posts\/5468\/revisions"}],"predecessor-version":[{"id":6503,"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/posts\/5468\/revisions\/6503"}],"wp:attachment":[{"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/media?parent=5468"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/categories?post=5468"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.waseda.jp\/fsci\/wise\/wp-json\/wp\/v2\/tags?post=5468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}