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.
The simulation and exergy analysis of a hybrid Solid Oxide Fuel Cell–Gas Turbine (SOFC–GT) power system are discussed in this paper. In the SOFC reactor model, it is assumed that only hydrogen participates in the electrochemical reaction and that the high temperature of the stack pushes the internal steam reforming reaction to completion; the unreacted gases are assumed to be fully oxidized in the...
A solar deep-freezing process has been designed. It aims at cooling down a cold box to about −20°C, using simple flat plate solar collectors operating at 70°C. This original process involves two cascaded thermochemical systems based on the BaCl 2 /ammonia reaction. Its working mode is discontinuous as it alternates between a regeneration mode during daytime and a cold production mode during...
Fuel cells are still undergoing intense development, and the combination of new and optimized materials, improved product development, novel architectures, more efficient transport processes, and design optimization and integration are expected to lead to major gains in performance, efficiency, reliability, manufacturability and cost-effectiveness. Computational fuel cell engineering (CFCE) tools...
The primary aim of this work is to assess the long-term sustainability of the desalination technology in alleviating the global freshwater crisis. The Canary Islands (Spain) have a well-established experience in desalination and the Island of Lanzarote –whose water supply is entirely dependent upon this technology—is taken as an illustrative case study. Analytical information obtained from the Material...
This paper presents experimental performance of solar drying of rosella flower and chili using roof-integrated solar dryer and also presents modelling of the roof-integrated solar dryer for drying of chili. Field-level tests for deep bed drying of rosella flower and chili demonstrated that drying in the roof-integrated solar dryer results in significant reduction in drying time compared to the traditional...
Fossil fuels still constitute an important source of energy in the world, but they need to comply with more strict environmental requirements. The coal industry, the basic primary energy supplier to the Polish economy, not only faces new environmental regulations but also restructuring and changes in the industry's organisational structure. The issues of primary importance are the medium and long-term...
Optimization studies along with optimum parameter correlations, using constant area mixing model are presented in this article for ejector-expansion transcritical CO 2 heat pump cycle with both conventional and modified layouts. Both the energetic and exergetic comparisons between valve, turbine and ejector-expansions-based transcritical CO 2 heat pump cycles are also studied for simultaneous...
Electrical arc furnaces are commonly employed in industry to produce molten steel by melting iron and scrap steel. Furnace control is a necessary operation for production optimization. The principal parameters to be controlled are: maximum productivity requirements, minimum power off time, good power quality and safety. The aim of this study is to achieve all these objectives. Hence, because of the...
Two biomass gasification concepts, i.e. indirectly heated, fast internally circulating fluidised bed (FICFB) gasification with steam as gasifying agent and two-stage, directly heated, fixed bed Viking gasification are compared with respect to their performance as gas generators. Based on adjusted equilibrium equations, the gas composition and the energy requirements for gasification are accurately...
An Agreement of Cooperation was concluded in 2008 on the setting up of an Energy Security Centre amongst the Hungarian Ministry of Defence, the Ministry of Economy and Transport, the Ministry of Foreign Affairs, the National Office for Research and Technology and the Prime Minister's Office. This paper summarizes the findings for the setting up of the Centre and creating the necessary conditions required...
Up to recently 2-D solid oxide fuel cell (SOFC) modelling efforts were based on global kinetic approaches for the methane steam reforming and water gas shift reactions (WGS) or thermodynamic equilibrium. Lately detailed models for elementary heterogeneous chemical kinetics of reforming (HCR) over Ni–YSZ anode became available in literature. Both approaches were employed in a quasi 2-D model of a planar...
In this study a model of the Irish energy-system was developed using EnergyPLAN based on the year 2007, which was then used for three investigations. The first compares the model results with actual values from 2007 to validate its accuracy. The second illustrates the exposure of the existing Irish energy-system to future energy costs by considering future fuel prices, CO 2 prices, and different...
The operation and performance of a SOFC (solid oxide fuel cell) stack on biomass syn-gas from a biomass gasification CHP (combined heat and power) plant is investigated. The objective of this work is to develop a model of a biomass-SOFC system capable of predicting performance under diverse operating conditions. The tubular SOFC technology is selected. The SOFC stack model, equilibrium type based...
A more realistic theoretical simulation model for a tubular solar adsorption refrigerating system using activated carbon–methanol (AC/M) pair has been introduced. The mathematical model represents the heat and mass transfer inside the adsorption bed, the condenser, and the evaporator. The simulation technique takes into account the variations of ambient temperature and solar radiation along the day...
Stringent grid codes imposed by transmission system operators (TSOs) have led wind turbine manufacturers to overdesign their products. As an individual power generator, each single wind turbine has to meet those regulations. However, in a “farm” like configuration, a different approach can be taken. This paper describes how renewable energy generator units can be simplified in order to bring manufacturing...
Direct solar drying characteristics of Amelie and Brooks mangoes were experimentally determined using a solar dryer made up of four trays and used under weather conditions of fruit harvest period. Direct solar drying curves were established, fitted using 10 mathematical models and simulated with a direct solar drying model. Effective diffusivity, drying rates and drying efficiency were estimated for...
This study was conducted on irrigated and dryland wheat fields in Canterbury in the 2007–2008 harvest year based on an extensive process of data collection involving a questionnaire and interviews. Total energy consumption in wheat production was estimated at 22,566 MJ/ha. On average, fertilizer and electricity were used more than other energy sources, at around 10,654 (47%) and 4870 (22%) MJ/ha,...
This paper presents the ability of the existing Chinese energy system to integrate wind power and explores how the Chinese energy system needs to prepare itself in order to integrate more fluctuating renewable energy in the future. With this purpose in mind, a model of the Chinese energy system has been constructed by using EnergyPLAN based on the year 2007, which has then been used for investigating...
Energy consumption from the residential sector is a complex socio-technical problem that can be explained using a combination of physical, demographic and behavioural characteristics of a dwelling and its occupants. A structural equation model (SEM) is introduced to calculate the magnitude and significance of explanatory variables on residential energy consumption. The benefit of this approach is...
Start-up time is one of the important factors that limit the application of high temperature polymer electrolyte fuel cells in several areas. Present work involves the analysis of different warm-up methodologies to analyse the start-up time for phosphoric acid doped PBI membrane based fuel cells. With this objective a number of three dimensional thermal models have been developed. Different heating...
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.