The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In an attempt to improve the forecasting accuracy of crude oil price fluctuations, a new neural network architecture is established in this work which combines Multilayer perception and ERNN (Elman recurrent neural networks) with stochastic time effective function. ERNN is a time-varying predictive control system and is developed with the ability to keep memory of recent events in order to predict...
The Compressed Air Sector accounts for a mean 10% worldwide electricity consumption, which ensures about its importance, when energy saving and CO2 emissions reduction are in question. Since the compressors alone account for 15% overall industry electricity consumption, it appears vital to pay attention to machine performances.The paper presents an overview of present compressor technology and focuses...
Energy efficiency in industries is one of the dominating challenges of the 21st century. Since the release of the eco-design directive 2005/32/EC in 2005, great research effort has been spent on the energy efficiency assessment for energy using products. The ISO (International Organization for Standardization) standardization body (ISO/TC 39 WG 12) currently works on the ISO 14955 series in order to...
A reverse-flow fixed bed reactor concept for CLC (chemical-looping combustion) is explored. The limitations of conventional fixed bed reactors, as applied to CLC, are overcome by reversing the gas flow direction periodically to enhance the mixing characteristics of the bed, thus improving oxygen carrier utilization and energy efficiency with respect to power generation. The reverse-flow reactor is...
We present an extensive study to measure CO2 uptakes on various AC (activated carbons) such as Maxsorb III, ACF-A20, BPL, Norit and honeycomb monolith for the temperatures ranging from 303 K to 363 K and pressures up to 10 MPa. These adsorbent samples were characterized using adsorption of nitrogen, XRD (X-ray diffraction), FTIR (Fourier transform infrared) and SEM (scanning electron micrography)...
Free-piston engine generator is an unconventional engine, which abandons the crank and connecting rod mechanism. This paper focused on a numerical simulation for the research on the combustion characteristics of a free-piston diesel engine generator. An iteration numerical simulation method was presented by adopting coupled models of zero-dimensional dynamics, multidimensional scavenging and combustion...
Uncertainties exist widely at the planning and design stages of district cooling systems, which have significant impacts on the design optimization. This paper therefore proposes a design method for district cooling systems by quantifying the uncertainties, which is so-called uncertainty-based design optimization method. Uncertainties in the outdoor weather, building design/construction and indoor...
A geothermal power plant model depends on the variations not only the temperature, but also, geochemical, and physical features of resources. Most of the geothermal brines in the world and in our country contain dissolved minerals and NCGs (non-condensable gases). These minerals precipitate from the solution and non-condensable gases flash depending on the changes of temperature and pressure during...
State-of-the-art integration scenarios of calcium looping (CaL), which is an emerging CO2 capture technology, assume that excess heat is used to raise steam for the steam cycle and result in a net efficiency penalty of 6.0–8.0% points. In this study, a concept using the supercritical CO2 cycle (s-CO2) instead of the conventional steam cycle is proposed. Retrofit of CaL with recompression s-CO2 cycle...
The utilization of energy efficient CHP (combined heat and power) systems provides opportunities for GENCOs (generation companies) to simultaneously increase their economic benefits and decrease environmental emissions. The goals of this study are to develop and simulate a novel approach for optimal economic dispatch scheduling for a GENCO to maximize economic profit and minimize environmental emissions...
We present a framework for incorporating weather uncertainty into electricity demand forecasting when weather patterns cannot be assumed to be stable, such as in climate change scenarios. This is done by first calibrating an econometric model for electricity demand on historical data, and subsequently applying the model to a large number of simulated weather paths, together with projections for the...
The European Commission is preparing a new regulatory initiative for monitoring CO2 emissions and fuel consumption of Heavy-Duty Vehicles in Europe. The new methodology is based on a combination of component testing and computer simulation of the vehicles' fuel consumption. A study was launched aiming to demonstrate that the approach is accurate and representative of the actual performance of vehicles...
Commercialization of peat briquetting technology was analyzed to know whether the technology is economically viable or not compared to commercialization of charcoal. The investigation of economic viability was assessed from raw-peat production to briquetting technologies. The briquettes were made by naturally dried of peat from Bisika, Bahimba, Ndongozi and Nyirabirande bogs, through a rotary pulverizer...
The dynamic model of an adsorber unit used as thermal energy storage device immersed in water is presented. The system operates with the silica-gel/water pair and is capable of storing the thermal energy received from the surrounding water (e.g., excess heat input from a hot water storage tank), in order to give it back later to the water as adsorption heat. The model was developed following a lumped...
Departing from the prior literature on the energy consumption-economic growth linkages, this paper aims to quantify the asymmetric impact of unpredictable variations in energy use on GDP (gross domestic product) volatility across the high- and low-volatility regimes in the United Kingdom. For this purpose, the paper utilizes quarterly and monthly data on energy consumption and real GDP, covering the...
In this study, synchrotron X-ray imaging is used to investigate the water transport inside newly developed GDM (gas diffusion medium) in polymer electrolyte membrane fuel cells. Two different measurement techniques, namely in-situ radiography and quasi-in-situ tomography were combined to reveal the relationship between the structure of the MPL (microporous layer), the operation temperature and the...
Bagasse is an abundant by-product from sugarcane production that can be used for conversion into biofuels. Nonetheless, the recalcitrant structures of lignocellulosic fibers required a pretreatment prior conversion into biofuels. In this study, four mechanical deconstruction methods were compared in terms of energy demand and energy efficiency at lab scale: BM (ball mill), VBM (vibratory ball mill),...
In the present work the transient behavior of ejectors is explored experimentally and numerically. The main goal is to achieve an appropriate numerical model for predicting transient phenomena in ejectors. To validate the numerical results, an experimental test rig was built up and a set of experiments was performed. Results showed a good agreement between experiments and numerical simulations and...
Tidal stream turbines offer a promising means of producing renewable energy at foreseeable times and of predictable quantity. However, the turbines may have to operate under wave-current conditions that cause high velocity fluctuations in the flow, leading to unsteady power output and structural loading and, potentially, to premature structural failure. Consequently, it is important to understand...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.