Optimization of the Performance of Micro Hydro-Turbines for Electricity Generation

Rural electrification has long been the most important topic on the development agenda of many countries. The needs for power supplies to rural areas increased significantly in the past decades. Extending electricity grids to rural areas is of a very high initial cost and is not viable economically. Micro hydroelectric power plants provide a good economical solution, which is also environmentally very friendly. The current study concentrates on selecting and optimizing a suitable cross-flow micro-turbine to be used in micro hydroelectric power plants. Cross-flow turbines are in general of simple structure, low cost, easy to fabricate and of modest efficiency. The main purpose of the present work is to optimize the performance of a selected turbine by establishing the optimal turbine’s design parameters. A complete analysis of the internal flow, which is of turbulent, two-phase and three dimensional in nature, was undertaken by simulating it using various CFD simulation codes. This study reports on the flow simulation using ANSYS CFX with a two-phase flow model, water-air free surface model and shear stress transport (SST) turbulence model. Prediction velocity and pressure fields of inside the turbine are, subsequently, used to characterize the turbine performance for different geometric parameters including the number of runner blades, the angle of attack, the ratio of inner to outer diameter, the nozzle profile, the blade profile, the nozzle throat width, the nozzle to runner blades width and the runner blades width to outer runner diameter. The results revealed the highly complex nature of the flow and provided a very good insight to the flow structure and performance optimization parameters.Kurdistan Regional Governmen

The Small Head Criterion in Hydropower and understanding the Dimensions of Renewable Energy with Water Resources

The Habilitation thesis unravels the questions in defining the head parameter for small hydropower in order to meet the challenges of diverse end use applications with electricity on one side and water supply on the other. The thesis sets a limiting criterion between 1.5 and 5 meters to explore both conventional and unconventional turbomachinery. However, with respect to water supply as end use, it strongly advocates non turbine technologies like ram pump that are more efficient at lower flows

Small-Scale Hydropower and Energy Recovery Interventions: Management, Optimization Processes and Hydraulic Machines Applications

Several topics in the small-scale hydropower sector are of great interest for pursuing the goal of a more sustainable relationship with the environment. The goal of this Special Issue entitled “Small-Scale Hydropower and Energy Recovery Interventions: Management, Optimization Processes and Hydraulic Machines Applications” was to collect the most important contributions from experts in this research field and to arouse interest in the scientific community towards a better understanding of what might be the main key aspects of the future hydropower sector. Indeed, the Guest Editors are confident that the Special Issue will have an important impact on the entire scientific community working in this research field that is currently facing important changes in paradigm to achieve the goal of net-zero emissions in both the energy and water sectors

Development of a more fish-tolerant turbine runner, advanced hydropower turbine project

Alden Research Laboratory, Inc. (ARL) and Northern Research and Engineering Corporation (NREC) conducted a research program to develop a turbine runner which will minimize fish injury and mortality at hydroelectric projects. ARL?NREC have developed a runner shape which minimizes the number of blade leading edges, reduces the pressure versus time and the velocity versus distance gradients within the runner, minimizes or eliminates the clearance between the runner and runner housing, and maximizes the size of the flow passages, all with minimal penalty on turbine efficiency. An existing pump impeller provided the starting point for developing the fish tolerant turbine runner. The Hidrostal pump is a single bladed combined screw/centrifugal pump which has been proven to transport fish with minimal injury. The focus of the ARL/NREC research project was to develop a new runner geometry which is effective in downstream fish passage and hydroelectric power generation. A flow of 1,000 cfs and a head in the range of 75 ft to 100 ft were selected for conceptual design of the new runner. Conceptual design of the new runner began with a re-evaluation of studies which have been previously conducted to identify probable sources of injury to fish passing through hydraulic turbines. Criteria relative to hydraulic characteristics which are favorable for fish passage were prepared based on a reassessment of the available information. Important criteria used to develop the new runner design included low pressure change rates, minimum absolute pressures, and minimum shear. Other criteria which are reflected in the runner design are a minimum number of blades (only two), minimum total length of leading edges, and large flow passages. 86 figs., 5 tabs

Mathematical Modelling of Energy Systems and Fluid Machinery

The ongoing digitalization of the energy sector, which will make a large amount of data available, should not be viewed as a passive ICT application for energy technology or a threat to thermodynamics and fluid dynamics, in the light of the competition triggered by data mining and machine learning techniques. These new technologies must be posed on solid bases for the representation of energy systems and fluid machinery. Therefore, mathematical modelling is still relevant and its importance cannot be underestimated. The aim of this Special Issue was to collect contributions about mathematical modelling of energy systems and fluid machinery in order to build and consolidate the base of this knowledge

Fluid/Structure Interactions

This Special Issue contains 12 papers devoted to fluid/structure interaction (FSI) problems. The main feature of the problems is an interface on which consistent boundary conditions for both the liquid and the solid regions are formulated. The presented studies cover a wide range of problems and methods for their solution, including problems of weak, or one-way interaction, in which the effect of interface deformation on the fluid flow can be neglected, as well as problems of the strong interaction, for which the interface change affects both the flow and the structure behaviour. The interest in FSI problems is very great due to their practical importance. Recent developments in engineering have led to advanced formulations of FSI problems. Some of them could not be formulated several years ago. The presented papers demonstrate progress in both numerical algorithms, mathematical apparatus and advanced computational techniques. In this issue, we have tried to collect different FSI problems, new mathematical and numerical approaches, new numerical techniques and, of course, new results, which can provide an insight into FSI processes

Dynamic conversion of solar generated heat to electricity

The effort undertaken during this program led to the selection of the water-superheated steam (850 psig/900 F) crescent central receiver as the preferred concept from among 11 candidate systems across the technological spectrum of the dynamic conversion of solar generated heat to electricity. The solar power plant designs were investigated in the range of plant capacities from 100 to 1000 Mw(e). The investigations considered the impacts of plant size, collector design, feed-water temperature ratio, heat rejection equipment, ground cover, and location on solar power technical and economic feasibility. For the distributed receiver systems, the optimization studies showed that plant capacities less than 100 Mw(e) may be best. Although the size of central receiver concepts was not parametrically investigated, all indications are that the optimal plant capacity for central receiver systems will be in the range from 50 to 200 Mw(e). Solar thermal power plant site selection criteria and methodology were also established and used to evaluate potentially suitable sites. The result of this effort was to identify a site south of Inyokern, California, as typically suitable for a solar thermal power plant. The criteria used in the selection process included insolation and climatological characteristics, topography, and seismic history as well as water availability

Advances in Theoretical and Computational Energy Optimization Processes

The paradigm in the design of all human activity that requires energy for its development must change from the past. We must change the processes of product manufacturing and functional services. This is necessary in order to mitigate the ecological footprint of man on the Earth, which cannot be considered as a resource with infinite capacities. To do this, every single process must be analyzed and modified, with the aim of decarbonising each production sector. This collection of articles has been assembled to provide ideas and new broad-spectrum contributions for these purposes