During the last years, special attention has been paid to renewable polygeneration technologies, able of simultaneously producing thermal, cooling, electrical energy and desalinated water from seawater. This paper focuses on an innovative polygeneration system driven by renewable energy sources, including the following technologies: hybrid photovoltaic/thermal collectors, concentrating paraboli...

In this work, single-stage and two-stage tubular solid oxide fuel cell (SOFC)/gas turbine hybrid cycles are comparatively examined from the energy and exergy viewpoints. For this purpose, mass, energy and exergy balances are applied to all components of the cycles. The behavior of tubular solid oxide fuel cell modeled in this study is validated with the experimental test data of tubular SOFC de...

The concept of exergy is defined and applied to district heating systems. The influence from different reference state conditions and system boundaries are explained in some detail. The aim is to show the simplicity and value of using the concept of exergy when analyzing district heating processes. The exergy factor is introduced and applied for a number of Swedish and Danish district heating s...

Advanced exergy analysis is a tool to split the exergy destruction of the system to achieve a better perspective about the potentials of a system for improvements. In addition, the component interactions and their exergy destruction dependency with the other equipment are investigated through the advanced exergy analysis. For this purpose, it divides the exergy destruction calculated by convent...

In this publication, we present an energy and exergy analysis of the Szewalski binary vapor cycle based on a model of a supercritical steam power plant. We used energy analysis to conduct a preliminary optimization of the cycle. Exergy loss analysis was employed to perform a comparison of heat-transfer processes, which are essential for hierarchical cycles. The Szewalski binary vapor cycle cons...

The impulse turbo expander (ITE) is employed to replace the throttling valve in the vapor compression refrigeration cycle to improve the system performance. An improved ITE and the corresponding cycle are presented. In the new cycle, the ITE not only acts as an expansion device with work extraction, but also serves as an economizer with vapor injection. An increase of 20% in the isentropic effi...

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...

In this paper, a novel poly-generation system for olefin and power production from natural gas is proposed, which integrates hydrocarbon production and the combined cycle power generation. Economic and technological evaluation based on the internal rate of return (IRR) and exergy efficiency is performed. The energy integration results in the proposed poly-generation system for simultaneous prod...

The paper illustrates some aspects of energy conversion processes during underground electric train operation. Energy conversion processes are explained using exergy, in order to support transport system sustainability. Loss of exergy reflects a loss of potential of energy to do work. Following the notion that life in Nature demonstrates sustainable energy conversion, we approach the sustainabi...

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...