Three alternatives for integrating a solar field with the bottoming cycle of a combined cycle plant are modeled: parabolic troughs with oil at intermediate and low cycle pressures and Fresnel linear collectors at low cycle pressure. It is assumed that the plant will always operate at nominal conditions, using post-combustion during the hours of no solar resource. A thermoeconomic study of the o...

A chemical equilibrium model was developed to predict the product composition of a biomass gasification system using highly preheated air and steam. The advantages and limitations of this system were discussed from a thermodynamic viewpoint. The first and second law analyses have been conducted for various preheating temperatures and steam/biomass mass (S/B) ratios. The results demonstrated tha...

In this study thermodynamic performance analysis of a combined organic Rankine cycle and ejector refrigeration cycle is carried out for use of low-grade heat source in the form of sensible energy. Special attention is paid to the effects of system parameters including the turbine inlet temperature and turbine inlet pressure on the characteristics of the system such as ratios of mass flow rate, ...

a new method of optimization on linear parabolic solar collectors using exergy analysis is presented. a comprehensive mathematical modeling of thermal and optical performance is simulated and geometrical and thermodynamic parameters were assumed as optimization variables. by applying a derived expression for exergy efficiency, exergy losses were generated and the optimum design and operating co...

in this research, energetic andexergetic analysis of calcium oxide formation, co2 emissions, andenvironmental effects during the clinker production process in rotary kilnare investigated. first the energy and exergy analysis of rotary kiln were carried out according to the first and second law of thermodynamics based on dead state, respectively. consequently, the amount of co2 emissions associa...

Several approaches to quantum gravity (including the model of superplastic vacuum; Diakonov tetrads emerging as bilinear combinations fermionis fields; BF-theories gravity; and effective acoustic metric) suggest that in general relativity metric must have dimension 2, i.e., [g??] = 1/[L]2, irrespective spacetime. This leads “dimensionless physics” discussed [1]. Here we continue exploit this un...

The cement industry is one of the most energy and carbon-intensive industries. The energy and carbon reduction is an important issue in this industry. The present work considers the use of alternative fuels in the cement kilns. The amounts of excess air, the location of fuel and air entrance, as well as the amount of produced gas stacks, are the main design and operational variables in the kiln...

The performance characteristics of an ejector-expansion refrigeration cycle (EEC) using R32 have been investigated in comparison with that using R134a. The coefficient of performance (COP), the exergy destruction, the exergy efficiency and the suction nozzle pressure drop (SNPD) are discussed. The results show that the application of an ejector instead of a throttle valve in R32 cycle decreases...

The present article is dedicated for evaluating the power generation sub-sector in terms of energetic and exergetic aspects. In this regard, energy and exergy utilization efficiencies during the period 1989-2006 are assessed based on real data obtained from main generators in Jordan. Sectoral energy and exergy analyses are conducted to study the variations of energy and exergy efficiencies for ...

The main goal of this paper is to analyze the exergy losses during the shock and rarefaction wave of hydrogen-air mixture. First, detonation parameters pressure, temperature, density, and species mass fraction are calculated for three cases where the hydrogen mass fraction in air is 1.5%, 2.5%, and 5%. Then, exergy efficiency is used as objective criteria of performance evaluation. A two-dimens...