an experimental and theoretical energy and exergy analysis was conducted for a cylindrical cavity receiver employed in a parabolic dish collector. based on simultaneous energy and exergy analysis, the receiver average wall temperature and overall heat transfer coefficient were determined. a simplified nusselt number for heat transfer fluid (htf) through the receiver as a function of reynolds an...

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...

Natural gas is often associated with nitrogen and heavy compounds. The Heavy components in the natural gas not only can feed downstream units, owing to the low temperature process may be formed solid as well. Therefore, heavy components separation can be a necessity and produce useful products. Virtually, all natural gases are containing nitrogen ​​that would lower the heating value of natural ...

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...

Heating, cooling and lighting appliances in buildings account for more than one third of the world’s primary energy demand. Therefore, main components of the building heating systems play an essential role in terms of energy consumption. In this context, efficient energy and exergy utilization in HVAC-R systems has been very essential, especially in developing energy policies towards increasing...

The recent work is dedicated to the study of behaviour of exergy and structural exergy in physical models of aquatic ecosystems—mesocosms and microcosms and in Lake Baikal. The results of field experiments with mesocosms on Lake Baikal, containing natural plankton assemblage, and laboratory experiments with microcosms containing Daphnia magna and Chlorella vulgaris demonstrated decrease of the ...

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...

C3MR, MFC, and DMR processes in an integrated LNG-NGL-NRU structure are investigated using the conventional and advanced exergy and exergoeconomic analyses. The results of advanced exergy analysis reveal that in most of the equipment, the highest amount of irreversibility is occurred because of endogenous exergy destruction. In C3MR process, compressor C5 with 9730 kW; in MFC process, compresso...

the present research proposes and optimizes the performance of a novel solar-driven combined cooling, heating, and power (cchp) kalina system for two seasons—winter and summer—based on exergy, exergo-economic, and exergo-environmental concepts applying a non-dominated sort genetic algorithm-ii (nsga-ii) technique. three criteria, i.e. daily exergy efficiency, total product cost rate, and total ...