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Behaviour of Boiler Steel Exposed to Combustion Gases Containing Bromide and Chloride Additives
Vered Atiya Zuckerman,
Rinat Ittah,
Mira Freiberg Bergstein,
David Itzhak
Issue:
Volume 3, Issue 4, August 2014
Pages:
162-167
Received:
16 March 2014
Accepted:
17 July 2014
Published:
30 July 2014
Abstract: Mercury emissions from coal-fired power plants need to be reduced. In a coal-fired power plant, mercury enters the system primarily with the coal, and exits the system as bound particle compounds, soluble mercury or vapor-phase mercury. Oxidized mercury is effectively removed in wet flue gas desulfurization scrubbers – WFGD.one of the options for enhancing the process of mercury absorption is adding oxidizing agents such as bromide/bromine or chloride/chlorine. The present work describes simulation tests performed in order to evaluate the effect of bromide/chloride additions on the behavior of various steels under a combustion environment in a diesel fed steam boiler. The tested samples A209-T1A, A213-T11, A213-T22 and AISI 1020 were exposed at two locations in the boiler system: inside the flame chamber near the wall and in the middle of the stack at a temperature of 250- 300° C for 3 months. XRD and SEM techniques were used to analyze and to inspect the crystallographic structure. The results clearly show that high temperature interaction between the metal surface and the fire combustion products lead to the deposition of a protective layer composed mainly of CaSO4, FeSO4 and Fe3O4. Negligible weight loss was detected in all the tested cases. No harmful effect was detected in the presence of bromide, added as CaBr2, or chloride, added as CaCl2, to diesel fuel, up to a level of 1000 ppm.
Abstract: Mercury emissions from coal-fired power plants need to be reduced. In a coal-fired power plant, mercury enters the system primarily with the coal, and exits the system as bound particle compounds, soluble mercury or vapor-phase mercury. Oxidized mercury is effectively removed in wet flue gas desulfurization scrubbers – WFGD.one of the options for ...
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Analysis of Demand and Supply of Electrical Energy in Cameroon: Influence of Meteorological Parameters on the Monthly Power Peak of South and North Interconnected Electricity Networks
Flora Isabelle Métégam Fotsing,
Donatien Njomo,
Réné Tchinda
Issue:
Volume 3, Issue 4, August 2014
Pages:
168-185
Received:
17 July 2014
Accepted:
28 July 2014
Published:
10 August 2014
Abstract: Following the unbalanced provision between supply and demand of electrical energy in Cameroon, it is necessary to perform an analysis of the data since it can provide essential information for an optimal management of the power supply system. This study presents on the one hand an analysis of electrical energy demand and supply in Cameroon, and, on the other hand, the modeling of the monthly peak of the main interconnected network in Cameroon, namely South Interconnected Networks (RIS) and North (RIN) networks using econometrical methods. Meteorological parameters (monthly maximal temperatures and humidity) are considered as exogenous variables of this application. Following the seasonality observed during various months, the introduction of terms of monthly seasonal as well as an average coefficient Ci peculiar to each month will also be introduced into the linear regression model to evaluate the most suitable one for this modeling. From the above analysis, it appears that meteorological parameters have a significant influence on the monthly peak in both networks. As well as the coefficients of these parameters are not the most significant of the various models, the absence of these parameters in different models leads to an increase Akaike (AIC) and Schwartz (SC) criteria. However, the best model is based on the minimum AIC and SC. The monthly peak in both systems is observed at the same time (20h) and one a working day. This peak may be influenced by other parameters such as the return to households and their consumption pattern, the type of equipment they use amongst other.
Abstract: Following the unbalanced provision between supply and demand of electrical energy in Cameroon, it is necessary to perform an analysis of the data since it can provide essential information for an optimal management of the power supply system. This study presents on the one hand an analysis of electrical energy demand and supply in Cameroon, and, on...
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Influence of Socio-Economic Indicators on Electricity Consumption of Low Voltage Customers in Cameroon
Flora Isabelle Métégam Fotsing,
Donatien Njomo,
Réné Tchinda
Issue:
Volume 3, Issue 4, August 2014
Pages:
186-203
Received:
16 July 2014
Accepted:
25 July 2014
Published:
10 August 2014
Abstract: In this paper, the demand of Low Voltage electricity customers in Cameroon using electricity as an energy source beginning from the period 1975 to 2011 is modeled. This approach aims to study the consumption determinants (macro- economic indicators, demographic indicators and lagged consumption of low voltage electricity) of low Voltage Customers and to analyze those determinants that have a strong influence on consumption. Parameters estimated by EVIEWS 7.2 software for linear and exponential (CooB-Douglas) models were used. The results show that CooB-Douglass models are better than the linear model. It also shows that: (i) the best linear model is a function of delayed consumption〖 C〗_(t-1) ; overall gross domestic product ((〖GDP_g)〗_t) and population (P_t ); (ii) the best model CooB-Douglas is a function of delayed consumption〖 C〗_(t-1) , the global gross domestic product ((〖GDP_g)〗_t) and the number of subscribers (S_t). It noticed that the macroeconomic indicators have a better influence on demographic consumer’s indicators and that the absence of the delayed consumption variable in a model causes autocorrelation of the residuals models.
Abstract: In this paper, the demand of Low Voltage electricity customers in Cameroon using electricity as an energy source beginning from the period 1975 to 2011 is modeled. This approach aims to study the consumption determinants (macro- economic indicators, demographic indicators and lagged consumption of low voltage electricity) of low Voltage Customers a...
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Experimental Test of the Tool for the External EMF Removing Dents on a Car Body
Issue:
Volume 3, Issue 4, August 2014
Pages:
204-208
Received:
13 August 2014
Accepted:
28 August 2014
Published:
20 September 2014
Abstract: This paper is dedicated to experimental study of pulsed electromagnetic attraction based upon recently developed tool design – “Inductor System with an Attracting Screen (ISAS)” for the repair technology of the external dent removing on a car body. The concept of attraction in this inductor system is based upon induced currents flowing in the same directions in the accessory screen and in the sheet metal blank, which, according to Ampere law, results in attraction forces between the screen and sheet metal blank. The more detailed information about ISAS is represented by Batygin (2006 [7], 2014 [8]). The main feature of this system is that the inductor is placed on the external side of the accessory screen. So, the induced currents in the parallel flat screen and sheet blanks are being excited by the penetrating magnetic field of the external source. Should mark this tool is capable of applying attraction forces to sheet metals of any physical nature as magnetic and stainless steel or aluminum. The conducted tests have shown a high effectiveness of suggested tool for the non-contact external flattening a car body in real production conditions. The represented work was done in the Laboratory of the Electromagnetic Technologies of the Kharkov National Automobile & Highway University, Ukraine.
Abstract: This paper is dedicated to experimental study of pulsed electromagnetic attraction based upon recently developed tool design – “Inductor System with an Attracting Screen (ISAS)” for the repair technology of the external dent removing on a car body. The concept of attraction in this inductor system is based upon induced currents flowing in the same ...
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Biodiesel, HSD, and JP-8 Combustion Process and Emission Characteristics in a Dual-Stage Fuel Injection Condition
Issue:
Volume 3, Issue 4, August 2014
Pages:
209-216
Received:
18 August 2014
Accepted:
1 September 2014
Published:
20 September 2014
Abstract: This research was focused on an investigation of the effect of injection dwell time in a dual-stage injection on the combustion and emission characteristics of biodiesel using an optically accessible single-piston diesel engine. In addition, the results from biodiesel combustion and emission characteristics were compared to those of fossil fuels such as HSD and JP-8 using combustion process visualization as well as emission analyzer. Regarding combustion characteristics, JP-8 showed the highest peak in-cylinder pressure and rate of heat release in comparison to biodiesel and HSD because the higher lower heating value and vaporization characteristics of JP-8 improved premixed combustion. However, the IMEP of JP-8 was lower than the corresponding pressure of HSD. From the viewpoint of emissions, biodiesel had reduced emissions of NOx, HC, CO, and CO2 compared to fossil fuels regardless of the injection dwell time. The natural luminosity combustion images indicated that the biodiesel fuel had a shorter ignition delay, and the combustion progress of JP-8 was accelerated due to superior vaporization, although the initial combustion was slightly delayed in the second injection phase compared to biodiesel and HSD.
Abstract: This research was focused on an investigation of the effect of injection dwell time in a dual-stage injection on the combustion and emission characteristics of biodiesel using an optically accessible single-piston diesel engine. In addition, the results from biodiesel combustion and emission characteristics were compared to those of fossil fuels su...
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