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Any effort with the aim of increasing the total electrical power generation (EPG) due to the existed constraints in vessels is desired in power plants. Using Organic Rankine Cycle (ORC) for recovering waste heat of an exhausting gas is considered as an auxiliary way for improving EPG value. In this study, four ORC arrangements were first modeled for six refrigerants by EES software and the first and second laws of thermodynamics efficiency (ηI and ηII, respectively) and mass flow rate were studied for these cycles. Based on modeling results, the best arrangement was selected for each refrigerant such as; F‐type (Reference cycle+ Intermediate recuperator+ Final recuperator) for R123, H‐type (Reference cycle+ Intermediate recuperator) for R114 and n‐butane and R‐type (Reference cycle + Final recuperator) for n‐pentane, n‐heptane, and toluene. The ηI value as a technical objective function was then optimized for the above cycles by Aspen HYSYS. n‐heptane and toluene cycles were chosen due to higher first‐law efficiency value and then were studied under different source temperature condition and n‐heptane cycle showed better adaptability. Afterward, exergoeconomic was applied on n‐heptane cycle and maximum cycle pressure was chosen as a design variable for economically optimizing net final income (NFI). Finally, NFI value is increased from 423.1$/kW·h to 609.9$/kW·h about 44.2%, while the second‐law efficiency value is just decreased from 25.6% to 20.6% about 5%.

The main aim of this research is focused on determining the velocity and particle density profiles across the flame propagation of microlycopodium dust particles. In this model, it is tried to incorporate the forces acting on the particles such as thermophoretic, gravitational, and buoyancy in the Lagrangian equation of motion. For this purpose, it is considered that the flame structure has four zones (i.e., preheat, vaporization, reaction, and postflame zones) and the temperature profile, as the unknown parameter in the thermophoretic force, is extracted from this model. Consequently, employing the Lagrangian equation with the known elements results in the velocity distribution versus the forefront of the combustion region. Satisfactory agreement is achieved between the present model and previously published experiments. It is concluded that the maximum particle concentration and velocity are gained on the flame front with the gradual decrease in the distance away from this location.

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In this study, exergy analysis, energy analysis, and mathematical modeling are performed in a 35 MW solar‐fossil fuel power plant. The losses of exergy and energy in different components and also changes of the efficiency of exergy and energy are analyzed at a specific day, 20th June. The assumed power plant in this study is Solar Electric Generating Station VI (SEGS VI), located in California's Mojave Desert. A parametric study, under different working conditions, including different working pressures, temperatures, collector output temperature, steam flow rate, and heat transfer fluid (HTF) flow rate is studied and the effect of variation of parameters on the performance of the plant is investigated. Authors found that, the maximum exergy loss happens in the collector and the maximum energy loss occurs in the condenser. Energy analysis shows that 47% of the total loss energy in the cycle happens in the condenser, as the main component that wastes energy. From exergy analysis, the collector and then boiler are the main components wasting exergy where 68.32% of total exergy loss occurs in these two components in hybrid mode (solar‐fossil fuel). Exergy and Energy efficiency variations throughout the day show that minimum exergy efficiency (32.7%) and maximum energy efficiency (23%) occurs at 12 am. Exergy efficiency variation versus turbine inlet pressure shows that the maximum exergy efficiency (26%) accure at 95 bar. The changes of the absorbed heat and solar irradiation of the 20th of June shows a good agreement with the measured data in validated reference.