Sharif Digital Repository

Electric arc furnaces are used to make steel from scrap iron in steel industry. Nowadays, the aim of more researches in this area is to increase yield of furnace and it's compatibility with environment. One of the methods to achieve these purposes is to control the off-gas system as relative pressure in furnace would be kept negative. Because the combustion gases inside the furnace must not leak into the plant environment. However for preventing of loss of energy, the amount of this negative number must be small. In this paper, new intelligent control method named fuzzy emotional control, applied to off- gas system to control the relative pressure in the furnace and its result is compared to... 

Dynamic contact angle measurement; as a standard method for surface wettability analysis, is usually conducted through the analysis of sessile drops formed following the low rate injection of fluid from beneath through a drilled hole via an injection needle. However, understanding/characterizing the changes of drop contact angle from the point where the flat solid surface begins is not well discussed yet. Moreover, during the evaluation of size-dependent behavior of contact angle of millimeter-scale drops, the effect of the drilled hole is ignored. In this regard, in the current study, the experimental and thermodynamic characterizations of the sessile drop advancing contact angle... 

To mitigate global warming and fossil fuel shortages a novel oxy-fuel combustion power plant integrated with a power to gas system is proposed. A net-zero emission MATIANT cycle with inherent CO2 capture ability is selected as the power cycle also providing the CO2 and power demand of the power to gas system, which comprises a proton exchange membrane electrolyzer for hydrogen production and a Sabatier reactor for methanation. A techno-economic investigation, a multi-objective optimization, and a sensitivity analysis are carried out. A comprehensive economic method that covers all economic aspects is utilized, and a Sabatier reactor model which considers the possibility of the presence of... 

Reinforcing the correlation between Gas and Electricity Systems (G&ESs) susceptible to diverse factors ranging from anthropogenic climate change to the advent of new conversion/generation technologies has remarkably brought into focus the co-expansion of G&ESs using a new concept so-called Energy Hub (EH) as well as the potential of storage systems. To assess the effectiveness of EH approach and the role of storages in the coordinated plans of G&ES, this study proposes a comprehensive EH-based planning model for co-expansion of G&ES supply chains with respect to the role of Gas Storage Systems (GSSs). As a Mixed-Integer Linear Programming (MILP) problem, the model is applied to a real... 

Accurate determination of relative permeability curves and their hysteresis is vital for reliable prediction of the performance of oil and gas reservoirs under enhanced recovery processes. Two out of the three available approaches to simulate three-phase relative permeability hysteresis are based on two-phase hysteresis. A few options (e.g., Carlson, Killough and Jargon models) are available in commercial reservoir simulators to account for hysteresis in relative permeability curves under two-phase flow. These models are based on the assumptions of water-wet state of the rocks, while most of the reservoir rocks are mixed-wet. As a result the aim of the present work is to evaluate the... 

Including gravity and wettability effects, a full analytical solution for the frontal flow period for 1D counter-current spontaneous imbibition of a wetting phase into a porous medium saturated initially with non-wetting phase at initial wetting phase saturation is presented. The analytical solution applicable for liquid-liquid and liquid-gas systems is essentially valid for the cases when the gravity forces are relatively large and before the wetting phase front hits the no-flow boundary in the capillary-dominated regime. The new analytical solution free of any arbitrary parameters can also be utilized for predicting non-wetting phase recovery by spontaneous imbibition. In addition, a new...