Method of calculation of water-diverting structures of low-head hydroelectric power plant for power supply of small power consumers

In recent years and in many countries the economic development of distant regions is increasingly dependent on energy resources. This fact makes the world scientific community pay more attention to the renewable energy sources. Special attention is paid to the solar, wind and small hydropower for electrical consumers who have no possibility to connect to the central power supply lines. In the countries that have water resources the financial support is given to the development of small and micro hydropower stations. The present work presents the results of the research on the improved method of calculation of water-diverting structures of low-head hydroelectric power plant with an installed cross-jet hydro turbine that is actual for the power supply of small power consumers. The presented method can be used for the preliminary analysis of morphometric characteristics of water course as well as the basic parameters of a cross-jet hydro turbine.

Vortex profile analysis under different diffuser size for inlet channel of gravitational water vortex power plant

Hydropower is a renewable technology to store the amount of electricity which is the least expensive. Gravitational Water Vortex Power Plant is an ultra-low head micro hydropower system working ranging from 0.7 m to 2m without having the needs of a large reservoir and installation area. Several researches have been conducted on its basin configuration, orifice diameter, blade configuration, the geometry of the basin shape but not onto the addition of the diffuser at the inlet channel. The function of the diffuser is to direct the water into the basin allowing the water vortex to travel towards the tangential direction where this phenomenon will increase the rate of speed flow through the turbine. The simulation results showed that the addition of the diffuser has significantly increased the tangential velocity and the kinetic energy of the vortices. The increase in the velocity of the flow increased the height of the vortex which also led to the increase in the strength of the vortex and affects the vortex uniformity.

Optimization of Reaction Typed Water Turbine in Very Low Head Water Resources for Pico Hydro

The purpose of this research is to investigate the dominant parameters that influence the optimum performance of reaction typed turbine at very low water head. The concepts of conservation of mass, momentum and energy are utilised to explore performance characteristics using a graphical technique. Parametric analysis of the governing equation and experimental results were performed to show that the turbine diameter and nozzle exit area has a dynamic response to mass flow rate, angular speed, output power and efficiency. Depending on the nozzle diameter of (0.01 m, 0.006 m, and 0.008 m) and turbine pipe size with (diameter of 0.025 m and 0.015 m), six versions of prototype turbine Z-blade turbine were produced. All the turbines have been tested at 100 kPa static water pressures and below. According to a variety of experimental data for all types of turbines, the turbine diameter and nozzle exit area have a substantial impact on turbine performance, especially at high water heads. Despite differences in turbine length and nozzle exit area, more than 90 % of the pattern curves for rotational speed, water flow rate, and mechanical power were identical. Overall, the Z-blade turbine Type B outperforms, resulting in higher turbine efficiency at low head and low flow water condition.

Performance Analysis of a Low Head Water Vortex Turbine

A small hydropower plant is an environment-friendly renewable energy technology. The run-of-river type gravitational water vortex turbine can be designed to produce electricity at sites with low water heads. In this study, an experimental investigation was undertaken on this type of turbine with a water tank and a runner which is connected to a shaft. At the end of the shaft, a rope brake was attached to measure the output power, torque and overall efficiency of the vortex turbine by varying flow rates. The designed vortex turbine can achieve an overall efficiency of . The experimental results were validated with available data in the literature and theories associated with the turbine. The results also showed that the flow rate plays a vital role in generating power, torque as well as overall efficiency. The project was completed using local resources and technologies. Moreover, as water is used as the input power, this project is eco-friendly which has no adverse effect on the environment.

Application of CFD to the Design of Manifolds Employed in the Thermodynamic Method to Obtain Efficiency in a Hydraulic Turbine

This study presents the design and implementation of different types of manifolds (sampling system) to measure water flow properties (velocity, pressure, and temperature) through the high- and low-pressure section of a Francis-type low head hydraulic turbine (LHT of 52 m) to calculate it is efficiency using the Thermodynamic Method (TM). The design of the proposed manifolds meets the criteria established in the “International Electrotechnical Commission—60041” Standard for the application of the TM in the turbine. The design of manifolds was coupled to the turbine and tested by the Computational Fluid Dynamics (CFD) application, under the same experimental conditions that were carried out in a power plant, without the need for on-site measurements. CFD analyses were performed at different operating conditions of volumetric flow (between values of 89.67 m3/s and 35.68 m3/s) at the inlet of turbine. The mechanical power obtained and the efficiency calculated from the numerical simulations were compared with the experimental measurements by employing the Gibson Method (GM) on the same LTH. The design and testing of manifolds for high- and low-pressure sections in a low head turbine allows for the constant calculation of efficiency, avoiding breaks in the generation of electrical energy, as opposed to other methods, for example, the GM. However, the simulated (TM) and experimental (GM) efficiency curves are similar; therefore, it is proposed that the design of the manifolds is applied in different geometries of low-head turbines.

Noise Generation and Acoustic Impact of Free Surface Hydropower Machines: Focus on Water Wheels and Emerging Challenges

The noise generated by free surface hydropower machines, e.g., water wheels, has led to complaints and to restrictions in their operation in urban areas. This problem generally occurs when water wheels are not well designed and are installed without expertise. Despite the relevance of the problem, and the growing interest in the use of water wheels at existing low head barriers, the acoustic impact of water wheels has not yet been properly addressed by the scientific community. Therefore, in this manuscript, the importance of the problem and the related scientific challenges are discussed, supported by case studies and theoretical considerations. A literature review on the topic is carried out, although little information is available in the scientific domain. The aim of this work is to increase the awareness on this problem, in order to stimulate future research and to suggest useful guidelines for future water wheel projects, thereby increasing the water wheel potential and reducing noise disturbance for people.

Investigating barotrauma in juvenile salmon passing through a very low head turbine using response surface methodology

Although hydropower is a clean source of energy, in some cases, it can jeopardize the life of some species of riverine fish. Very Low Head (VLH) water turbine is an innovative design that aims at reducing the adverse effects of such hydroelectric facilities. In this research, two methodologies are integrated to investigate barotrauma in juvenile salmons passing through this particular turbine. First, to quantify barotrauma, we implement a method known as BioPA (Biological Performance Assessment) by combining the results of some laboratory experiments on juvenile Chinook salmon moving through a simulated turbine passage with the Computational Fluid Dynamics (CFD) simulation of the flow field in this environment. In the second part, we added surrogate-based modeling as a tool, which enabled us to study the effects of two geometrical parameters on the environmental performance of the VLH turbine with low computational costs. The results indicate a significant dependency between the installation angle of the VLH turbine and the severity of the barotrauma of this particular fish. In addition, further investigations suggest that the region near the middle of blades is the safest for fish in the case of decompression.

Effect of Exit Blade Angle on the Performance of Cross Flow Hydro Turbine: A Numerical Study

Cross-flow hydro turbines (CFHTs) are generally used in micro hydraulic power plants due to their simplicity in design and fabrication, moderate efficiency, ease of maintenance. The CFHT can be used in low flow and low head conditions with an efficiency of around 90% at rated conditions. However, the efficiency of the CFHT can further be improved by changing its geometric parameters Hence, in the present investigation, 3D unsteady simulations are performed in order to locate the exit blade angle (β2) with the intention is to improve the efficiency of the turbine. In the proposed investigation, the multi-physics FVM solver ANSYS Fluent has been used with the help of the SST k-ω turbulence model to carry out the unsteady simulations. The 3D unsteady simulations are performed by varying the exit blade angle (β2) from 60° to 90° to improve its efficiency when the rotational speed is fixed with the number of blades being 20. From the unsteady simulations, the maximum efficiency of the CFHT is at the exit blade angle (β2) = 80°.