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...

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...

Cascaded thermal storage, consisting of multiple Phase Change Materials (PCMs) with different melting temperatures, has been proposed to solve the problem of poor heat transfer caused by unavoidable decrease of temperature differences during heat exchange process. This paper conducts a theoretical study of the overall thermal performance for a cascaded thermal storage system. Both heat transfer...

This paper presents a detailed exergetic analysis of a novel high-temperature Solar Assisted Combined Cycle (SACC) power plant. The system includes a solar field consisting of innovative high-temperature flat plate evacuated solar thermal collectors, a double stage LiBr-H2O absorption chiller, pumps, heat exchangers, storage tanks, mixers, diverters, controllers and a simple single-pressure Com...

Energy, entropy and exergy concepts come from thermodynamics and are applicable to all fields of science and engineering. Therefore, this article intends to provide background for better understanding of these concepts and their differences among various classes of life support systems with a diverse coverage. It also covers the basic principles, general definitions and practical applications a...