توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱steam stripping, monomer removal, degassing, vinyl chloride.
نویسنده(ها): ،
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۵
Two different modeling techniques are introduced and compared for solid–state fermentation process in packed–bed bioreactors, in order to simulate and upscale these reactors; one based on a dynamic heat transfer model and the other based on a modified Damkohler number. The limiting parameter of upscaling bioreactors is the temperature of substrate at the top of reactor which ends or limits the growth of microorganisms in the fermentation process, therefore a critical bed height is required to be proposed by the model. The maximum bed height which can be used without undesirable temperatures being reached in the substrate bed is the critical bed height in the fermentation bioreactor process. Critical bed height depends on the microbial specific growth rate as well as superficial velocity and inlet temperature of the air. In this work, the mentioned two models were compared and the outlet temperature resulted by both techniques were obtained close together. It is concluded that, both models are in agreement and can be used as for upscaling these processes. Although the modified Damkohler number is a simple technique, it can be used Instead of heat transfer model. In addition, the effect of two different growth kinetics; logistic and exponential equation, are studied in the models comparatively and the effect of model variables, such as specific growth rate, and superficial velocity are investigated on the critical bed height and outlet temperature.<\div>

۲Daily Gas Demand Load Forecasting for Tehran, Based on Artificial Neural Network
اطلاعات انتشار: پنجمین کنگره بین المللی مهندسی شیمی، سال
تعداد صفحات: ۵
n this work, we forecast the gas demand load for Tehran city, based on the most important weather parameters, by using artificial neural network with multilayer back propagation, BP algorithm. At first, the effective daily temperature will be determined and then the data for last days for network training were used. The main advantage of this work is a good agreement of almost 93% with the real data. This network can further be developed to forecast gas load of other cities of Iran.<\div>

۳A CFD study on the convective heat transfer of Al2O3\Water nanofluids under laminar flow regime
نویسنده(ها): ، ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۱۰
This paper reports Computational Fluid Dynamics (CFD) investigations on the Nusselt number and heat transfer performance of Al2O3\Water nanofluids under laminar flow condition in circular tube submitted to a constant and uniform heat flux at the wall. A single–phase model is employedwith either constant or temperature dependent properties. The investigation is accomplished for size particles equal to 50 nm. Convective heat transfer coefficient for nanofluids is greater than that of the base liquid and heat transfer enhancement increases with the particle volumeconcentration. Higher heat transfer coefficients are detected in the case of temperature dependentsmodel and the heat transfer always improves, as Reynolds number increases. Moreover acomparison with the experimental data present in the literature is carried out and good conformity between the model predictions and the experimental data is achived<\div>

۴Nanofluids Heat Conduction Modeling Based on Nanolayer Thickness
نویسنده(ها): ، ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی شیمی، سال
تعداد صفحات: ۱۰
The nano particles have demonstrated great potential to improve the heat transfer characteristics of heat transfer fluids. Previously developed correlations have not completely predicted the anomalous increase in the thermal conductivity of nanofluids. In this paper, possible parameters responsible for this increase were studied. The heat transfer profile in the nanolayer region was combined with other parameters such as volume fraction, particle radius, thermal conductivity of the fluid, particle and nanolayer, to formulate a new correlation. Results predicting the thermal conductivity of nanofluids using the new correlation were compared with experimental results as well as studies by other researchers. Overall the comparison of the results obtained for the CuO\Water and TiO2\Water nanofluids studied shows that the correlation proposed is in closest proximity in predicting the experimental results for the thermal conductivity of a nanofluid. Also a parametric study to understand how a number of factors affect the thermal conductivity of nanofluids was performed using the newly developed correlation and led to some important conclusions<\div>

۵Numerical Investigation on the Applicability of Silica\Water Nanofluids in Porous Medium for EOR Enhancement
اطلاعات انتشار: اولین کنفرانس دوسالانه نفت، گاز و پتروشیمی خلیج فارس، سال
تعداد صفحات: ۵
The water injection is one of the common methods of enhance oil recovery. This process may be more efficient by using nanofluids injction instead of water. Nanoparticle can change the physical properties of water to produce nanofluids and this may lead to attain more oil production. In this study a mathematical and numerical model is developed to analyze the enhancement of oil recovery into the porous medium by using silica\water nanofluids. The results clearly show that, water saturation is significantly increased in porous core by adding a low concntration of silica nanoparticle into water. In addition, the oil recovery rises considerably.<\div>
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