Study and Characterization of a Spherical Solar Collector. Part II: Comparative Analysis with Flat-Plate Devices
Abstract
907 6721
Study and Characterization of a Spherical Solar Collector. Part II: Comparative Analysis with Flat-Plate DevicesAbstract
The paper analyses the performance of a spherical solar collector compared to the efficiency of a flat-plate solar collector, which is the type of solar collector that does not use a tracking system in collecting solar radiation for energy conversion. Spherical solar collector benefits from a constant value of the angle of incidence, which optimizes the solar radiation that strikes the absorber of the solar device and maximizes the energy collection. Besides, the spherical geometry has a larger area for equal dimen [...] 907 6721 |
Improving the Performance of Solar Thermal Energy Storage SystemsAbstract
In recent times, renewable energy resources have been greatly researched because of the increasing concern to minimize global warming and meet energy demands. Energy storage systems have become useful tools for sustainability and meeting energy needs. Solar energy has proven in recent times to be the primary and most prevalent option due to its environmental friendliness, availability, and minimal pollution. Effective utilization of available energy resources has led to developing new alternative energy devices lik [...] 1663 13505 |
Permeability, Compressibility and Pressure Prediction in Supercharged Wireline and FTWD EnvironmentsAbstract
In conventional wireline and LWD/MWD formation testing, downhole predictions for rock and fluid properties are based on simplified Darcy flow models, but only for mathematical expediency. These require initially constant pressures that are uniform throughout the reservoir. This limitation precludes common applications in overbalanced drilling, so that supercharge or near-well invasion effects - associated with rapidly decreasing pressures at the sandface where pressures are measured - are completely ignored. Such 1 [...] 1411 7791 |
Study and Characterization of a Spherical Solar Collector. I. Efficiency and Thermal Losses CoefficientAbstract
This paper studies and characterizes a solar collector with spherical geometry to produce hot water for sanitary and domestic applications and other facilities. The new geometry enlarges the solar collector surface and allows full sun tracking during the day without needing a solar tracking system. Although this geometry has been in use for some time, its market penetration is low due to the lack of perfect knowledge of solar collector behavior and the benefits compared with conventional solar collectors. The studi [...] 1045 7253 |
Effects of Waste Cooking Oil Biodiesel on Performance, Combustion and Emission Characteristics of a Compression Ignition EngineAbstract
With their higher sustainability index, biofuels, environmentally-friendly and renewable nature is a viable alternative energy source in the transportation sector. This study presents the effect of waste cooking oil (WCO) biodiesel on performance, combustion, and emission from a compression ignition engine. The biodiesel was blended with diesel in varying proportions of 5% biodiesel and 95% diesel (designated as B5), 10% biodiesel in diesel (B10), 15% biodiesel in diesel (B15), 20% biodiesel in diesel (B20), 50% bi [...] 1359 12572 |
A Review of Practical Applications of Fluid Flow and Associated Heat Transfer Modeling in WellboresAbstract
Investigations on two-phase gas/liquid flow in pipes have been under study for nearly six decades. These studies have significantly assisted in managing fluid flow in the wellbore and surface networks, leading to the separation of phases and transmission of oil and gas into the market. This study summarizes some of the main lessons learned in flow through wellbores. Besides understanding some of the fundamental principles, we focused on the practical items of interest: Conventional production scenarios for oil and [...] 1587 11607 |
Nonlinear Optimal Control for Six-Phase Induction Generator-Based Renewable Energy SystemsAbstract
The article aims at optimizing six-phase induction generator-based renewable energy systems (6-phase IGs or dual star induction generators) through a novel nonlinear optimal control method. Six-phase induction generators appear to be advantageous compared to three-phase synchronous or asynchronous power generators, in terms of fault tolerance and improved power generation rates. The dynamic model of the six-phase induction generator is first written in a nonlinear and multivariable state-space form. It is proven th [...] 1201 8314 |
Fixed-Switching Frequency Finite-State Model Predictive Thrust and Primary Flux Linkage Control for LIMAbstract
The special design of linear induction machines (LIMs) leads to adverse effects caused by the longitudinal and end effects. These effects make the thrust control of the LIMs most attractive because its value decreases sharply with the speed increase. Thus, finite-state model predictive control (FS-MPC) is developed to increase the performance of the LIMs. However, the variable switching frequency is the main drawback of this control. Consequently, the main objectives of this paper are to propose FS-MPC with a const [...] 1163 7654 |
Non-Isothermal Compressible Flow Model for Analyzing the Effect of High CO2 Inlet Flow Rate on Particle Size in a Supercritical Antisolvent Processby
Abstract
In this work with CFD simulations, the evaluation of the supercritical anti-solvent (SAS) process for producing nanoparticles from an expanded solution of ethanol/solute in carbon dioxide is reported. The influence of the solution and antisolvent flow rates on mean particle size, the flow dynamic, and the supercritical mixture's jet velocity must be well established in the literature and analyzed. The high flow rate of the anti-solvent resulted in increased mean particle sizes for all studied cases. At the lowe [...] 1197 9039 |
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