Chemical Engineering
M. Ibrahim Abduljabbar; H. Ghafouri Taleghani; I. Esmaili Paeen Afrakoti
Abstract
In this research, gas sweetening process of the Iraq Majnoon refinery plant and its optimization scenarios were investigated using ASPEN HYSYS 8.4 and genetic algorithm optimization. First, values of optimization parameters such as the values of the population, generations and crossover for single and ...
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In this research, gas sweetening process of the Iraq Majnoon refinery plant and its optimization scenarios were investigated using ASPEN HYSYS 8.4 and genetic algorithm optimization. First, values of optimization parameters such as the values of the population, generations and crossover for single and multi-objective optimizations were obtained. The effect of temperature and molar flow of feed gas and make-up water on concentration of CO2 and H2S in the sweet gas were studied. The result showed that with increasing the temperature and molar flow of feed gas, the concentration of CO2 and H2S in the sweet gas was increased. The single and multi-objectives’ optimizations of process were carried out with minimizing the concentration of CO2 and H2S, minimizing the consumed energy of stripper and overall consumed energy of plant including energy of stripper and cooler. It was observed that for optimization of concentration of CO2 and H2S, mole fraction of CO2 and H2S decreased to minimum amounts of 5.52 e-4 and 6.84 e-9 between optimization data sets. Also, it was found that with increasing the number of objective functions of the optimization, the ability of the algorithm to reduce the amount of the objective functions decreases, because genetic algorithm should consider more constraints with increasing the number of objective functions. The novelty of this research was a comprehensive study of gas sweetening process optimization with single to four objectives.
Environment
H. Esmaeil Yazdi; A. M. Salehi
Abstract
Proper acoustic design is especially important in some buildings. For example, in concert halls, one of the desirable functional features is the proper transmission of music. In this regard, an indicator that can effectively show the quality of the received sound is the sound intensity, which is the ...
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Proper acoustic design is especially important in some buildings. For example, in concert halls, one of the desirable functional features is the proper transmission of music. In this regard, an indicator that can effectively show the quality of the received sound is the sound intensity, which is the purpose of this study is a way to optimize this indicator. Among the most effective variables that will affect the intensity of the received sound and also the important characteristics of the sound source are the frequency and octave of the sound, as well as the distance between the sound source and the receiver. In this research, a new method was proposed to investigate the effect of these three variables on the received sound intensity. In this regard, ODEON software, one of the most powerful software in acoustic design, was used and data analyses were implemented. Then, using full factorial method (one of the experimental design methods), targeted scenarios based on three independent variables were identified and by using the results of simulated scenarios, the linear relationship between the dependent variable (sound intensity) and independent variables (frequency, octave and distance) were developed. Using this linear relationship, it was found that the octave of sound has the greatest effect on sound intensity, and sound frequency and distance from the sound source were inversely related to the sound intensity.
Energy
H. Bagheri Sabzevar; Z. Erfan
Abstract
Today’s energy consumption is one of the most important causes of pollution around the world. Considering the building sector consumes the most energy, it should be seriously considered. In order to provide thermal comfort inside a building, energy is consumed, which can be managed using tools ...
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Today’s energy consumption is one of the most important causes of pollution around the world. Considering the building sector consumes the most energy, it should be seriously considered. In order to provide thermal comfort inside a building, energy is consumed, which can be managed using tools such as louvers that allow solar radiation to pass through the windows while reducing the amount of consumed energy. The goal of this paper is to find the optimal features for shading device of fixed louvers for the east, west, and south facades of the office building at Hakim Sabzevari University in terms of thermal efficiency using parametric analysis. For one year, three rooms on three floors of this building with window louvers at different depths, angles, and distances were thermally simulated with EnergyPlus software and the HoneyBee plugin in addition to the Galapagos plugin for optimization. Based on the optimized samples, it is possible to reduce the thermal energy consumption by 32.34%, 23.71%, and 30.2%, respectively using the ideal louvers on the east, south, and west facades. In terms of thermal efficiency, the distance between the blinds on the south facade and the angle between them on the east and west facades of a window louver are the most significant factors.
S. Abdoly Naser; F. Haghparast; M. Singery; H. Sattari Sarbangholi
Abstract
Iranian vernacular architecture has rich experiences in terms of coordinating with its surroundings. although, high energy consumption was one of the major concerns in the past decades. According to statistics presented by Iranian Statistics Center, 40% of the country's energy consumption is relevant ...
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Iranian vernacular architecture has rich experiences in terms of coordinating with its surroundings. although, high energy consumption was one of the major concerns in the past decades. According to statistics presented by Iranian Statistics Center, 40% of the country's energy consumption is relevant to the construction industry. However, about 70% of consumption is used solely for space heating and cooling. In the meantime, windows have a significant influence on the thermal performance. Ganjei-Zade House in Tabriz is one of the monuments and includes two parts. The north side of Qajar era and the western side was added to the former building in Pahlavi era. The present article deals with the study of the evolution of windows from Qajar to Pahlavi in Ganjei-zade house and the amount of heat dissipation from windows. These evaluations has been carried out by simulating Ganjei-zade house in the DesignBuilder software. The research related to this article was conducted based on analytic and comparative method and the purpose is to provide the important criteria for windows in residential buildings in the cold climate of Tabriz considering native architecture solutions in order to reduce heat dissipation. The conducted calculations confirm that the amount of heat losses from windows from Qajar to Pahlavi era, has been reduced by 22.2% and the amount of heat dissipation per square meter of windows from Qajar period to Pahlavi was decreased by 58.33%.
S. N. Nnamchi; O. A. Nnamchi; E. O. Sangotayo; S. A. Ismael; O. K. Nkurunziza; V. Gabriel
Abstract
The design of a flat-plate solar collector (FPSC) is accomplished by multiple input multiple output (MIMO) design technique. The design variables (absorber, fluid and glass temperatures; length, width, height of the FPSC) were the unknown variables in the commensurate thermal balance equations based ...
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The design of a flat-plate solar collector (FPSC) is accomplished by multiple input multiple output (MIMO) design technique. The design variables (absorber, fluid and glass temperatures; length, width, height of the FPSC) were the unknown variables in the commensurate thermal balance equations based on; component, overall and yardstick thermal balance on the FPSC. Then, simulator matrices were setup comprising of coefficient and column matrices of design functions. The elements of the coefficient matrix were the partial derivatives of the design functions with respect to the design variables. Besides the convective and radiative heat transfer coefficients were function of the design variables. The initial values of the design variables (307K, 334.5K, 368K, 2 m, 1 m, and 0.045m, respectively) were set, at the seventh iteration, the output variables (306.9K, 339.15K, 368.1K, 2.01m, 1.005m, 0.04m, respectively) merged as the design functions ® 0 with insignificant change in the design variables. The output results were used to simulate FPSC, to track its responses to changes in the physical conditions, the stimulation revealed some constraints in the design of the FPSC, which is vital information for the overall optimization of the FPSC. The design yardsticks; the thermal efficiency (0.76) and the effectiveness (0.4) are quite pragmatic. This shows that MIMO technique to thermal system design is effective as convergence among the design variables was sought. Moreover, MIMO considered all thermal losses instead of basing the yardsticks on top loss overall transfer coefficient alone; thus, neglecting sidewalls and base losses. Moreover, the advent of connecting box prepares the preheating unit for high temperature drying (> 150 oC) on integration with a reheating unit.
M. A. Mirrezaei
Abstract
In this study, in 2011 for the duration of two months, the dispersion of a major air pollutant, sulfur dioxide from gas flares of an oil field, in Iran, was investigated. Due to the complexity of meteorological parameters in modeling area, California Puff (CALPUFF) model was used in this study. CALPUFF ...
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In this study, in 2011 for the duration of two months, the dispersion of a major air pollutant, sulfur dioxide from gas flares of an oil field, in Iran, was investigated. Due to the complexity of meteorological parameters in modeling area, California Puff (CALPUFF) model was used in this study. CALPUFF is a more advanced model than AERMOD which considers the effects of meteorological parameters in coastal areas, which was applied with meteorological and geophysical parameters produced by the Weather Research and Forecasting (WRF) model for the selected days of modeling period to investigate the impact of these parameters on modeling results. Since there is no option in the model for flares, flare parameters including emission rate and effective height and diameter were calculated based on EPA method to simulate better the real condition of flaring. Simulation results revealed that CALPUFF model could adequately express the effect of meteorological condition on results of modeling in each hour of the simulation period. The results of the simulation showed that low-height flares have the most impact on the ground level concentration of air pollutant on the island. The effects of elevated flares were at a far distance from flaring activity and mostly occurred outside of the island. CALPUFF model showed excellent compatibility with meteorological data produced by WRF and could properly account for the effect of meteorological and terrain parameters on dispersion modeling.
A. A. Abbood Al-Khazzar
Abstract
In this study, PVsyst simulation software is used to analyze a PV grid tied system in a typical primary school in Iraq. The proposed system is 5kW which is affordable and applicable from the cost and required area points respectively. The monthly averaged electrical load for a typical school is approximately ...
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In this study, PVsyst simulation software is used to analyze a PV grid tied system in a typical primary school in Iraq. The proposed system is 5kW which is affordable and applicable from the cost and required area points respectively. The monthly averaged electrical load for a typical school is approximately calculated. The system simulation has been done for thirteen Iraqi provinces while it is described and its performance is analyzed in details for Baghdad city as an example. The performance ratio for the system in Baghdad is 0.825 and about 9.82MWhr is generated by the system per year, 62.7% is consumed by the load and the remaining is injected to the national grid. The results showed that the initial capital cost is 5,442$ which is returned after five and a half years. The cost of 1 kWhr if the system operates for 10 years is 0.058$. This study clearly demonstrates that photovoltaic power system can effectively assist the peak load on the grid. In addition, these systems are very economical/no maintenance project and can be hooked to any the peak time load.