Abstract Phase change materials (PCM) can increase the energy densities in thermal storage systems. Heat transfer rates PCMs are usually limiting, different improvement methods were used previously, such as fins or improved conductivities. Here, influence of fin geometries, PCM conductivity and discharge temperature secondary fluid investigated by modelling. The analysed outcomes their on store...

Through its ‘Column Targeting Tools’ the Aspen plus simulator performs the ‘Thermal Analysis’ for rigorous column (RadFrac) calculations and produce Column Grand Composite Curves (CGCC) and exergy loss profiles. The CGCC displays the net enthalpies for the actual and ideal operations at each stage, and the cold and hot heat utility requirements, while the exergy loss profiles indicate the level...

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...

The present paper describes the energy and exergy analysis of a reheat regenerative vapor power cycle. The plant consists of one boiler feed pump, one supercritical boiler, two steam turbines with a reheater in between, two feed water heaters (one open and one closed) and a condenser. The energy and exergy balance study has been carried-out for each component of the plant. Energy efficiency, ex...

Tubular solar thermal receivers suitable for central towers are modelled using energy and exergy analysis, in a way that allows individual inspection of the the irreversibilities associated with the various receiver heat transfer processes occurring. The model was used to compare the behaviour of four working fluids: molten salt (NaNO3/KNO3), liquid sodium metal, supercritical carbon dioxide, a...

Energy and exergy analyses were carried out for a pilot parabolic solar dish-Stirling System. The system was set up at a site at Kerman City, located in a sunny desert area of Iran. Variations in energy and exergy efficiency were considered during the daytime hours of the average day of each month in a year. A maximum collector energy efficiency and total energy efficiency of 54% and 12.2%, res...

Abstract: The influence of droplet size on exergy destruction rate in flow of highly concentrated oil-in-water emulsions was investigated experimentally in a cone and plate geometry. The oil concentration was fixed at 74.5% by volume. At this dispersed-phase (oil) concentration, two different droplet size emulsions were prepared: fine and coarse emulsions. The fine and coarse emulsions were mix...

A thermodynamic analysis of an operational 315 MW supercritical steam power plant (SPP) using the actual data is performed to assess the plant performance and identify the sites of energy losses and exergy destructions in each component of the plant. Various performance parameters such as component energy and exergy efficiencies, energy loss rate, exergy destruction rate, improvement potential ...