A Novel Approach to the Improvement of the Hydropower Plants Protective Measures—Modelling and Numerical Analyses of the Semi-Pneumatic Surge Tank

Adopting adequate operational and safety measures is a significant part of the investigation transient processes hydropower plants (HPPs), both throughout design stage prospective planning HPPs envisaged for refurbishment/uprating. One surge tank (ST) types, insufficiently researched so far, with potential positive techno-economical influence, semi-pneumatic (SPST). Since detailed analyses SPST have never been performed or published before, SPSTs examined here by presenting theoretical considerations, newly developed mathematical model comprehensive numerical simulations. The aim to improve performance open-air variations STs. Multiple simulations specific case-study HPP conclusions about peculiarities benefits implementation. Firstly, results existing as-built corresponding alternative compared, in order verify model. Variations main constructive parameters analyzed, determine sensitivity particular influences on versus its geometry alterations. conducted show that application brings behaviour improvement compared ST. Dimensions new aeration orifice could be smaller than ones previously defined: diameter optimized upper lower chamber core decreased 20% 12.5%, respectively.