Transient characteristics during power-off process in a shaft extension tubular pump by using a suitable numerical model. (February 2021)

• Record Type: Journal Article
• Authors: Kan, Kan; Chen, Huixiang; Zheng, Yuan; Zhou, Daqing; Binama, Maxime; Dai, Jing
• Is Part Of: Renewable energy. Volume 164(2021)
• Page Start: 109
• Page End: 121
• Publication Date: 2021-02
• Subjects: Transient characteristics -- Shaft extension tubular pump -- Numerical model -- Rigid-lid hypothesis -- Volume of fluid; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2020.09.001
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: For most of low-head pump stations, pumps simultaneously undertake important tasks such as flood control, irrigation and drainage where more attention should be paid on involved hydraulic stability. In order to establish a suitable numerical prediction model, two kinds of water surface treatment namely volume of fluids (VOF) and rigid-lid hypothesis (RLH) methods, for upstream and downstream reservoirs, are presented and corresponding results are compared. System transient characteristics during power-off process are predicted, where the obtained maximum runaway speed by VOF method is found to be closer to the one from experimental results. The dynamic parameters of VOF method change slower than those of RLH method and the static pressure peak value is smaller. The usage of VOF method to water dynamics at the reservoir's free surface makes the water flow in reservoirs relatively smooth, whereas large-scale vortices appear in reservoirs for the RLH method. Moreover, the turbulent kinetic energy is found to be larger if the reservoir's free surface is not taken into consideration. This article established a novel and accurate prediction model, which otherwise would provide the foundation of further studies in terms of transient characteristics prediction within pumping stations taking into account the air-water interactions. Highlights: Two numerical methods are applied for predicting transient characteristics of pump. External characteristics and flow regime are compared and analyzed for the two cases. The VOF method is more accurate in predicting the maximum runaway speed of the pump.