Abstract
Energy contributes significantly in almost all aspects of human life as well as economic activities and plays a crucial role in the infrastructural development of a county to alleviate poverty. Generating energy from a renewable source such as small hydropower through the application of pump operating as a turbine mode called Pump as Turbine is one of the best alternatives to provide clean and inexpensive energy. Using Pump as Turbine helps in generating reasonably priced hydroelectric power for communities in underdeveloped counties. This study investigates the effects of internal flow behaviour and performance of Pump as Turbine under different rotational speed and flow rate. The rotational speed is an essential physical parameter as it affects the Pump as Turbine operation. A model-specific speed centrifugal pump model with head 32 (m), flow rate of 12.5 (m3/h) and the rotational speed of 2900 rpm, has been selected for the study. Numerical simulations have been conducted using the k-ω turbulence model to solve three-dimensional (3D) equations. The pump mode experimental data were used to confirm the results for better analysis. The results predicted that vortex and turbulent kinetic energy increase per rotational speed increase. Also, at the higher rotational speed, very high recirculation of flow is detected at the blade suction chamber, although the pressure side has a smooth flow. This study provides beneficial information which will serve as a reference to help improve PAT performance along with selecting PAT for a small hydropower site. Future works will consider the impact of blade thickness and cavitation in Pump as Turbine.
Highlights
Natural energy resources such as small hydropower have in recent times contributing significantly to a larger piece of the national energy resource types
A lot of researches have been conducted on Pump as Turbine (PAT) since 1930 [15], using diverse types of pumps and the results show that PAT could stand selected as a perfect choice for hydro energy production considering its good benefits [16,17,18]. e advantages of using PAT in preference to small hydropower turbines were outlined by [19]
Pressure Distribution of PAT. e characteristics of a 3D pressure distribution of PAT under different speed conditions at the best efficiency point (BEP) have been discussed. e difference in rotational speed pattern with the change in rotational speed results are shown in Figure 4. e results reveal that, as the rotational speed increases along with the fluid flow within the domains, pressure decreased from the leading edge to the trailing edge of the PAT impeller
Summary
Natural energy resources such as small hydropower have in recent times contributing significantly to a larger piece of the national energy resource types. Generating energy from nonrenewable sources is very familiar but is mostly through the use of expensive conventional hydro turbine [1, 2] As a result, they are using Pump as Turbine (PAT) for energy generation which can contribute significantly in stabilising electric power system to elevate the usage of other renewable sources such as thermal power plants which are rapidly depleting the environment. A lot of researches have been conducted on PAT since 1930 [15], using diverse types of pumps and the results show that PAT could stand selected as a perfect choice for hydro energy production considering its good benefits [16,17,18]. It is necessary to conduct this study to analyse the internal flow physics of PAT to provide useful information for PAT selection in hydraulic power sites and serve as a reference for further research. Other researchers considered simulation and power system analysis in their studies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
