volume-08-Issue 2 (2014)
Some Aspects of the Rheological Behaviour of Coal Water Slurries
IJTEE, volume-08, Issue 2 (2014) , PP 103 - 107
Published: 20 Nov 2014
by Sunita Panda, R.K. Swain from Sunita Panda, R.K. Swain
Abstract: Initially coal-slurry fuels were based on coal-oil mixtures. Now the emphasis is largely on coal-water fuels. Since most of the studies have been done with coals available in the western countries having low ash content, an attempt has been made in this paper to study some aspects of the rheological behaviour of coal slurries prepared out of coals having high ash content. Crisis in the volatile oil markets experienced in the seventies have promoted renewed interest in coal-based fuel technologies. Coal-slurry fuels have emerged as viable technical alternatives for oil and gas in utility and industrial boilers. Despite current low prices and the abundance of oil, concerns over its long-term availability and price, as well as strategic considerations make coal-slurry technology attractive. In this paper an empirical relationship has been established among apparent viscosity and volume fraction of solids for coal having high ash content. read more... read less...
Keywords: Oil agglomeration, froth flotation, apparent viscosity, HAAKE rotational viscometer
Application of Taguchi’s Methods for Optimizing Organic Rankine Cycle for Recovering Low Grade Industrial Waste Heat
IJTEE, volume-08, Issue 2 (2014) , PP 91 - 101
Published: 20 Nov 2014
by Umesh Kumar, Munawar N. Karimi from Jamia millia Islamia, New Delhi, India, 110025
Abstract: This research attempts the optimization of Organic Rankine Cycle (ORC) by Taguchi’s robust design methods for generating electricity from industrial waste heat. Experimental results and data from previous researches is used to assign the relative importance of parameters. Parameters selected are waste stream temperature, waste stream flow rate, type of refrigerant and turbine speed. Optimum combination of these control parameters is obtained by using Taguchi’s techniques. Individual effect of parameters on the performance of Organic Rankine Cycle is calculated. Interaction effect of parameters on the performance of ORC is also calculated. A percent effect of individual parameters on performance is estimated by using ANOVA. Using this procedure, an optimal cycle can be obtained for maximum efficiency within available sources. read more... read less...
Keywords: Electricity generation; Waste heat recovery; Optimization; Taguchi's method; Organic Rankine cycle; ANOVA
Modeling and Simulation of the Drying of Beech Timber (Fagus sylvatica) Using Oscillating Regimes
IJTEE, volume-08, Issue 2 (2014) , PP 83 - 90
Published: 20 Nov 2014
by Merlin Simo Tagne, Yann Rogaume, André Zoulalian from Douala Higher Institute of Technology (DIT), Douala, Cameroon, PO Box 1623 b University of Lorraine, LERMaB, ENSTIB, Epinal, France, PO Box 1041, 88051 Epinal cedex 9
Abstract: This paper represents a numerical study of the massive (60mm) and thin (38mm) wood drying using oscillating drying regimes applied on beech timber (Fagus sylvatica). All thermo-physical properties relative of studied wood is taken from the literature on appropriate experiments. We showed that Luikov’s model can be used to predict temperature and moisture content evolutions using oscillating regimes. First numerically tests on 60mm timber wood consists in increasing and decreasing alternation of the drying parameters (temperature), at the rising 12-15°C and at the descent 10- 12°C, every alternation being higher than the precedent with 2-4°C. Second numerical test consists to oscillate the values of equilibrium moisture content with the oscillation amplitudes of ±10% and ±20% at the frequencies of 6hours. These practical experiments are detailed in the literature. Luikov’s model gives satisfactory results, according to the experiments obtained in the literature. But, convective transfer coefficients are function of each experiment and we observed a short difference between oscillation amplitudes of ±10% and ±20% on moisture content evolution. Thus, Luikov’s model can be a tool to study oscillation drying timber in order to reduce consumption of energy during the drying process. read more... read less...
Keywords: Drying, Heat and Mass Transfer, Luikov’s Model, Simulation, Oscillating Regimes, Beech Wood.
Thermoeconomic Analysis of Multi-Stage Thermoelectric Cooler
IJTEE, volume-08, Issue 2 (2014) , PP 77 - 82
Published: 19 Nov 2014
by Sudhanshu Sharma, V. K. Dwivedi, S. N. Pandit from Department of Mechanical Engineering, Mewar University, Chittorgarh, Rajasthan, India, 312901, Department of Mechanical Engineering, Galgotias College of Engineering & Technology, Uttarpradesh, India, 201306, Department of Mechanical Engineering, Noida Institute of Engineering & Technology, Uttarpradesh, India, 201310
Abstract: In this paper a two stage thermoelectric cooler which has total 50 elements out of which 30 elements are on hotter side and 20 elements are on colder side, analyzed on the basis of the principles of thermoeconomics. Exergy destruction has been used to calculate the second law efficiency. Then the exergy has been coupled with unit cost of exergy to calculate the cost of refrigeration produced. The model has been analyzed for a particular life cycle of thermoelectric cooler (TEC) where the operating conditions change with the variation in cold side and hot side temperatures. Two cases have been considered. In first case the cold side temperature is varied with hot side temperature maintained as constant. In second case hot side temperature is varied with cold side temperature maintained as constant. The analysis shows that on the basis of thermoeconomics the first case is favorable but the comparison on the basis of coefficient of performance, rate of refrigeration and second law efficiency show that the second case is favorable. read more... read less...
Keywords: Thermoelectric cooler, Thermoeconomic, Exergy, COP, Rate of refrigeration, Second law efficiency
Crumb Rubber Effect on Acoustic Properties of Self- Consolidating Concrete
IJTEE, volume-08, Issue 2 (2014) , PP 69 - 76
Published: 19 Nov 2014
by Malek Jedidi, Ali Boulila, Omrane Benjeddou, Chokri Souss from Institut Supérieur des Etudes Tecnologiques de Sfax, Département de Génie Civil, B.P.88, 3099 Sfax, Tunisia, Université de Tunis El Manar, Ecole Nationale d’ Ingénieurs de Tunis, Laboratoire de Génie Civil, B.P.37,Tunis Belvédère, 1002,Tunisia, Université de Sfax, Faculté des sciences de Sfax, Laboratoire de Géoressources, Matériaux, Environnement et Changement Globaux, B.P.1171 Sfax, Tunisia
Abstract: Several researches have been conducted to find a practical and environmentally sound solution of the problem of scrap tires. In this context, an experimental study was conducted to provide more data on the effect of crumb rubber on the acoustic properties of self-consolidating concrete SCC. To this end, Parallelepiped and cylindrical specimens were prepared by varying the proportion of crumb rubber with percentages of 0 %, 10 %, 20 % and 30 % of the volume of gravel. Properties such standardized level difference, sound absorption at different frequency and noise reduction were investigated. The results showed that the sound absorption and noise reduction coefficient were increased according to the increase of the percentage of crumb rubber. The self-consolidating concrete rubber SCCR has better acoustic properties in comparison with SCC. read more... read less...
Keywords: Crumb rubber, Self-consolidating concrete, Standardized level difference, Sound absorption, Noise reduction, Sound transmission class.
ENGREF-FCAP “Flying Wood’’ Method to Characterize Unknown Central Africa Tropical Woods Relative of Their Drying
IJTEE, volume-08, Issue 2 (2014) , PP 63 - 68
Published: 19 Nov 2014
by Merlin Simo-Tagnea, Romain Rémond from Douala Higher Institute of Technology (DIT), Douala, PO Box 1623, Cameroon, University of Lorraine, LERMAB, ENSTIB, Epinal, PO Box 1041, F-88051 cedex 9, France
Abstract: When we want to opposite excessive exploitation of some species of wood in the tropics, it is important to characterize unknown woods with intention of their valorization. This is most urgent than in the majority of these countries, only some species are highly exploited and the species less valorized are destroyed during the researches of known species in the forests. ENGREF-FCAP ‘’flying wood’’ method is an alternative to classify unknown woods according to their drying. This method permits us to evaluate deformations of wood sample during a dissymmetrical drying and to estimate also evolution of their drying kinetic. The radius of the curvature of samples and drying kinetic permit us to compare the attacks of the drying air conditions on the samples. When these attacks are capable to destroy the quality of wood, a review of these conditions permits to want favorable conditions until we obtained the drying table of unknown woods read more... read less...
Keywords: ENGREF FCAP ‘’flying wood’’ method- Tropical woods- Drying- Characterization- LERMAB