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Operating Efficiency Improvement Considerations
Published in Heinz P. Bloch, Allan R. Budris, Pump User’s Handbook, 2021
Heinz P. Bloch, Allan R. Budris
The objective of many PAT (pump as turbine) applications is to pump and retrieve water between two reservoirs at different elevations, as a means of energy storage and retrieval, to take advantage of lower energy rates at off peak periods, or to level out uneven energy generation.
Computational research on the formation mechanism of double humps in pump–turbines
Published in Engineering Applications of Computational Fluid Mechanics, 2021
Yong Liu, Dezhong Wang, Hongjuan Ran
As the key energy conversion component of pumped-storage power stations, pump–turbines have the functions of both pump and turbine. Owing to their special structure, pump–turbines have hump problems under pump mode. During the process of pump starting, stopping, and working conditions changing, severe vibration and noise appear when passing through the hump region, and the loop flowrate oscillates hugely, even leading to pump surge. Humps not only threaten the safety, reliability, and service life of pumps, but also lead to operational failure (Lu, 2018; Yin, 2012). With the continuous large-scale production of renewable energy by means such as nuclear power, solar power, and wind power, the power grid system increasingly relies on pumped storage technology to cope with load changes, and pump–turbines need to be started and stopped more frequently. Thus, hump problems are even more critical (Capelo et al., 2017; Li, 2017; Li et al., 2020; Sampedro et al., 2021). Pump–turbines have always developed rapidly in the direction of higher heads, and the maximum head of a single-stage pump–turbine has reached about 800 m. How to deal with humps is becoming more and more important (Li, 2017; Li et al., 2017). Hump problems are key to restricting the development of pumped storage technology, and it has always been a research hotspot, but the hump formation mechanism has not been fully understood.
A Novel Vertical Axis Parallel Turbines System for In-pipe Hydropower Generation: Conceptual Design and Preliminary Experiment
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Muhammad Fazrin Abdullah, Iswadi Jauhari, Mohd Faizul Mohd Sabri, Nik Nazri Nik Ghazali
Rentricity is intelligent in-pipe hydropower that uses the SCADA integration system. The system works together with the pressure reducing valve which is placed in a parallel manner to the hydropower. The water flow is diverted from the main pipe into the in-pipe hydropower before returning back into the main pipe (Rentricity,Creating a Smart Water Grid 2018). The system uses pump as turbine (PAT) to generate electricity, which helps to reduce the R&D cost (Motwani, Jain, and Patel 2013). This hydropower system is capable of generating power from 5 kW up to 30 kW (Sustainable Energy and Monitoring Systems) and from 35 kW up to 350 kW (Flow to wire system).
Techno-economic analysis of In-stream technology: A review
Published in International Journal of Green Energy, 2023
Upendra Bajpai, Sunil Kumar Singal
Generally speaking, most nations have access to plentiful water resources and ideal circumstances for the development of SHPs, allowing them to produce clean power without harming the environment. For developing nations, RoR hydropower is particularly appealing (Berga 2016; Kuriqi and Jurasz 2022). The government of many countries started supporting it by providing subsidies, especially to RoR, and the technology proliferated on a global scale (Alban et al. 2019b). The technology is typically seen as environmentally friendly and sustainable. However, these hydropower projects can change the natural flow pattern and harm the fluvial ecology at various tropic levels (Alban et al. 2021). The primary environmental impacts of the three types of small run-off river hydropower systems- dam-toe, pondage, and diversion weir were discussed, and the dam-toe hydropower scheme was observed to be more eco-friendly compared to the pondage and diversion weir hydropower scheme (Alban et al. 2020). To minimize the environmental effect and safeguard the hydropower industry’s profit, the environment flow (e-flow) for the ROR scheme needed to be properly determined. Less e-flow did not always worsen habitat conditions, while greater e-flow did not always result in maximum habitat availability. The dynamic approach e-flow method produced consistent results and was better because it suggested 10–35% more hydropower with minimal impact on hydrological parameters (Alban et al. 2019a). To maximize power output and minimize detrimental effects on the riverine ecosystem, Suwal et al. (2020) created an optimization model for the cascade reservoir. The need for a large generation capacity in ROR systems could also be lessened by an energy storage device. Consequently, decreasing the quantity of water diverted and lowering the ecological effects. Several examples of energy storage systems (ESS) include sodium-sulfur batteries, compressed air energy storage, and pumped hydroenergy storage systems (Malka et al. 2022). In pumped hydroenergy systems, pump as turbine (PAT), which is a reversely operated pump, is employed. The turbine suffers from the problem of tip leakage vortex, tip leakage flow, and cavitation resulting in energy loss and reduced hydraulic efficiency (Kan et al. 2022). PAT cavitation is decreased via geometric design modification, and flow dynamics interference approaches, for example, by improving blade tip geometry, volute casing design, providing splitter blades, gap drainage blades, and J-grooves (Kan et al. 2022). Water, as a renewable energy source, possesses energy in two forms. The former is represented by the potential head, and the latter is represented by kinetic energy. In SHP schemes, this kinetic energy is available in the form of flowing water velocity in various environments such as rivers, canals, tidal, and marine water ways.