iran’s vast common natural gas resources and the necessity to extract and export it as liquefied natural gas (lng) to distances more than 3000km opens a lucrative field for researchers to optimize lng cycles. in this article heat integration in cryogenic cycles by determining interacycle partition temperature and optimizing refrigeration features like subcooler, presaturator, aftercooler, reboi...

in this paper, first a sensitivity analysis of parameters affecting the performance of the steam generator is performed. this process includes the pinch temperature difference and the gas velocity (width of the hrsg) as the operating parameter and geometrical parameters (fin’s thickness, fin’s height, number of fins in each inch, tube transverse pitch) for each pressure parts is carried out, an...

The location of heat transfer pinch point in evaporator is the base of determining operating parameters of organic Rankine cycle (ORC). The physical mathematical model seeking the location of pinch point is established, by which, the temperature variations both of heat source and working fluid with UA can be obtained. Taking heat source with inlet temperature of 160 C as example, the matching p...

We present a thermo-economic analysis of an Organic Rankine Cycle (ORC) for waste heat recovery. A case study for a heat source temperature of 150 ̋C and a subcritical, saturated cycle is performed. As working fluids R245fa, isobutane, isopentane, and the mixture of isobutane and isopentane are considered. The minimal temperature difference in the evaporator and the condenser, as well as the mi...

The paper reviews various representations of exergy and exergy losses in energy systems going from simple heat exchanger (heat transfer, dissipation and embedded exergy) to the exergy of full energy systems from fossil or non fossil resources (including the diffusion exergy). The systems shown include shell in tube heat exchangers, thermal power cycles, cogeneration, heat pump direct heating sy...

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...

This paper reports a plenary thermodynamic model of a novel solar system for water heating in buildings. Energy and exergy analyses are used to characterize the exergy destruction rate in any component and calculate system overall efficiency. The system consists of a solar evaporator, a heat exchanger to produce hot water, and an auxiliary pump. A computer simulation program using EES software ...