Twenty-five years ago, Gaggioli, Sama and Qian published a series of 10 “second law guidelines” for design and process engineers, nicknamed at that time “the Gaggioli-Sama rules”. These guidelines, some of them previously published by Sama between 1980 and 1983, are a compilation of “second law errors” to avoid in the design of energy conversion systems. The list was rearranged several times, u...

The Second Law of thermodynamics is known to be an essential guide for the improvement of energy conversion systems. Throughout the years it has been applied to various engineering methods in particular in methods based on exergy [1] including the 2 Law, thermoeconomics and exergoeconomics. It has also been used in graphically attractive energy integration techniques such as pinch technology an...

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...

Since 1960, LNG technology has been constantly evolving, and it has become an active subject of research in industrial and academic fields. The improvements in the natural gas liquefaction and shipping processes have led to a decrease in the total cost of the delivered LNG of approximately 30% in the last 20 years, mostly as a consequence of technological advancements. In this work a variant of...

In Kalina power generation as well as vapor absorption and refrigeration systems ammonia-water mixture has been used as working fluids. Unlike for pure components, binary mixtures additionally need mixture concentration to solve thermodynamic properties. A flowchart is developed to understand the computations of the properties. The thermodynamic properties for ammonia-water mixture have been ge...

The vitality of the society is strongly depending on the management of physical, environmental and human resources. The dilemma of the modern society can be stated: misuse of physical resources from poor understanding of concepts such as exergy, misuse of nature from ignorance of ecology and misuse of people or human intelligence from lack of democracy. Exergy is a well-established concept in e...

Metal Foam-enhanced Cascaded Thermal Energy Storage (MF-CTES) has been proposed to solve the problem of poor heat transfer during heat exchange process, which is caused by unavoidable decrease of temperature differences. This paper conducts a theoretical study examining the overall thermal performance of STES (Single-stage Thermal Energy Storage), CTES (Cascaded Thermal Energy Storage) and MF-C...

The application of ecological exergy as a suitable system-oriented development indicator of ecosystems and the estimation proposals from biomass are revised. DNA contents (C-values) of several groups of organisms are figured, either determined by flow cytometry or taken from literature. The applicability of DNA contents for determination of weighing factors to estimate ecological exergy from th...

This paper analyzes the energetic and exergy performance of an active magnetic regenerative refrigerator using water-based Al2O3 nanofluids as heat transfer fluids. A 1D numerical model has been extensively used to quantify the exergy performance of a system composed of a parallel-plate regenerator, magnetic source, pump, heat exchangers and control valves. Al2O3-water based nanofluids are test...