Geometrical effects on performance and inner flow characteristics of a pump-as-turbine: A review (original) (raw)
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Comprehensive Review of Pump as Turbine
Renewable Energy and Sustainable Development, 2019
The turbine is a heart of power generation in a hydroelectric power system. A variety of different turbines are available for that purpose. The common types of Hydraulic turbines are; Pelton, cross flow, Francis, Kaplan, and propeller turbine. However, using conventional turbines for low head and flow rate (i.e. micro hydropower) applications are not economically feasible. A low-cost alternative is to use the pump as a turbine. In this paper, existing Peer-reviewed articles from (Scopus, google scholar, umbrella, etc.) that are directly related to pump running as a turbine are collected and reviewed. Theoretical, numerical, and experimental investigations are considered. Performance improvement techniques for PAT are summarized and research gaps in related works are identified.
Pump as Turbine: Dynamic Effects in Small Hydro
Proceedings of the World Renewable Energy Congress – Sweden, 8–13 May, 2011, Linköping, Sweden, 2011
This work focuses on the hydraulic aspects of a Pump as Turbine (PAT) when subjected to different working conditions, including accidental situations. This will provide useful information for the choice of the most adequate solution and will ensure a co rrect design and safe operation of the installed equipments. This work is supported by experimental data obtained in a series of tests performed at the university's laboratory and by calibrated computational modelling. The obtained data was used to perform a sensitivity analysis on t he relation between discharge variation, runaway time and rotational speed and make inferences about the expected peak overpressure in an accidental situation. Based on the results, the hydropower system may be characterized by a r elevant set of calculated parameters that are of extreme utility in the construction and calibration of a computational model capable of accurately predicting different scenarios and alternatives.
Performance characteristics of pump-as-turbine for energy generation
2018
Using pump in reverse mode as hydraulic turbine is one of the best alternatives for small hydropower generation. It is also one of the best options for meeting energy needs and providing electricity in remote and rural areas. Economic growth through renewable energy and sustainable energy sectors will create more employment opportunities and improve the social conditions in the country. financial constraints are one of the major reasons why small hydro power sites are left untapped. Despite the very low operating costs of small and micro-hydro power, the initial investment costs are high, especially the cost of the turbine. The use of pumps as a turbine is a good-looking and excellent option. With the rising cost of electricity and fuel prices, small or micro hydropower is the COMMUNICATION Vol. 15, 2018 Indian Journal of Engineering ISSN 2319–7757 EISSN 2319–7765
Complexity
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 t...
Adaptation of Water Pump as a Micro Hydro-Turbine for Electricity Generation
FUOYE Journal of Engineering and Technology, 2018
The concern on the global environment has imposed restraints on the production of electricity. The emphasis recently is on the development of environmental friendly methods to promote sustainable power production as it is in micro hydro power generation. The running cost of such plants is low but initial capital cost can be relatively high. By reducing the equipment cost in micro hydropower system, micro hydro turbines can become more useful and easily affordable. Reducing the equipment cost by the use of centrifugal pump in reverse mode can be an alternative to conventional hydraulic turbine. This paper discussed the adaptation of a water pump to function as a small hydro-turbine to be utilized in small stream in rural areas. Annual rainfall data was obtained from a 14 year data from National Centre of Agricultural Mechanization (NCAM) to obtain the discharge from river Odurun. By using the codrier graph method, a pump with a diameter of 245 mm was chosen from three pump obtained f...
Investigation into the Internal Flow Characteristics of a Pump-turbine Model
The KSFM Journal of Fluid Machinery, 2015
This is a study about one of the most widely used hydro machinery all over the world-pump-turbine. The system has an impeller which pumps water to an upper reservoir during the night and the same impeller acts as a runner for turbine mode during the day for providing stable electrical power to the grid. The internal flow analysis is investigated in this study to help understand how the water passes through the passage of the vanes and blades, providing the designer with useful information on the behavior of recirculation flows which could reduce the efficiency of the pump-turbine. The 100 kW pump-turbine model has H = 32 m, Q = 0.336 m 3 /s and N = 1200 min-1. For this study there are 7 blades, 19 stay vanes and 20 guide vanes. From this study, it was observed that this pump-turbine design showed very good internal flow characteristics with no flow separation and no recirculation flows in normal operation mode.
Pumps as turbines: an unconventional solution to energy production
Urban Water, 1999
In any water system which has excessive available energy (e.g. natural falls, irrigation systems, water supply, sewage or rain systems), the application of a pump instead of a turbine, for energy production, seems to be an alternative solution with easy implementation and considerable equipment cost savings. Micro-hydropower corresponds to a typical renewable energy source without any relevant impacts, and has multiple advantages, as a decentralised, low-cost and reliable form of energy. Unconventional solutions are in the forefront of many developing countries to achieve energy self-suciency.
Assessment Performance of Pumps as Hydro-Turbines
The basic principle work of hydro-turbines are reversal of pumps, therefore, an alternative solution that can be developed in overcoming problem to get hydro turbines are by using pumps, by flowing water in the reverse direction through in the pumps, as hydro turbines. Those are supported by availability of pumps widely in the market and have been mass-produced hence they were relatively cheap. The aims of this research are to determine performances of pumps as turbines -reverse pumps. This experiment assesses performance of two small pumps that are centrifugal 'diffuser-pump' and 'volute-pump' as hydro turbines with various debit and head of water flow resource, such as output-powers and their efficiencies. The results show that the centrifugal diffuser-pump as hydro turbine performs maximum efficiency about 20,6%, where is as pump from its brochure suppose 47%. In the other hand, the centrifugal volute-pump as turbine achieves maximum efficiency about 32%, where is expected 26% as pump from its brochure. Both type of the pumps present that the maximum efficiency as turbines performed at head of water flow resource through the pumps as high as their maximum characteristic head of the pumps. Furthermore, both pumps as turbines generate high shaft revolution that was about 1.500 rpm at their maximum efficiency. Although those efficiencies are considerably low to an ideal efficiency 100%, however, the volute-pump as turbine performs a reasonably efficiency (32%) that higher than (at least is same as) the efficiency of its pump characteristic (26%), and this pump available very widely in the market. Should be pointed out that bigger dimension pumps propose higher efficiency up to about 86%, therefore they are expected to give higher efficiency as well. So, centrifugal volute-pumps are potential alternative solution to be used as hydro turbines.
Everything you need to know before working with a pump as a turbine
Revista Facultad de Ingeniería, Universidad de Antioquia, 2024
Electric power generation is one of the most relevant issues in recent decades. This energy can be obtained through non-renewable sources, renewable sources, and especially non-conventional renewable sources. Within this last category, we can classify the use of a Pump as a turbine (PAT). The pumps are hydraulic machines designed for energy expenditure. Thanks to being reversible machines, PATs can be used in their reverse mode of operation to extract valuable energy from the fluid. However, this use can generate some inconveniences in its process, ranging from assembly, characterization, and hydrodynamic phenomena. This article provides the basic theoretical concepts and operating curves typically used for pumps as turbines. In addition to a global approach to the hydrodynamic phenomena associated with using pumps as turbines, there are cases of vibration, cavitation, and rotating stalls. All this panorama is complemented with some examples of application and economic analysis that ratify the advantages of using pumps as turbines as a reliable source of energy generation.
CFD Modelling of Pump as Turbine with Various Number of Blade for Microhydro System
Journal of Applied Science & Process Engineering, 1970
Pump as Turbine is an electromechanically component that is largely used in microhydro system. The main advantages of pump as turbine compared to commercially available turbines are lower cost, easier to maintain and readily available. These key features make them appealing to conditions in many developing countries. However, pump as turbine has poor hydraulic performance and low efficiency thus modifications were applied to improve the performance. The aim of this paper is to study the effect of impeller blade number to the pump as turbine performance. The investigation was carried out by using commercial Computational Fluid Dynamic (CFD) software, ANSYS CFX. A centrifugal pump with a specific speed of 70 with an impeller diameter of 214.0 mm was used to generate the CAD model. The original number of the blade was at 6 and varied to 5, 7 and 8 while other geometric dimensions were kept unchanged. The simulation results reveal that the highest efficiency was attained at 7 blade numb...