TThe present paper evaluates the plan of combustion air pre-heater installation on the fired heater from thermodynamics and thermos-economics point of view. As a real case study, one of the fired heaters (H_101) of Distillation unit in Tehran Oil Refinery, Iran, is intended. With applying an air pre-heater in this study, flue gases temperature falls down from 430 ºC to 200ºCand combustion a...

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...

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...

a new method of optimization on linear parabolic solar collectors using exergy analysis is presented. a comprehensive mathematical modeling of thermal and optical performance is simulated and geometrical and thermodynamic parameters were assumed as optimization variables. by applying a derived expression for exergy efficiency, exergy losses were generated and the optimum design and operating co...

This study presents comparative energy and exergy analyses of a single cylinder, four stroke Ruston diesel engine. The test was conducted by varying the load between zero and maximum while keeping the engine speed constant. Then, using the steady-state data along with energy and exergy balance equations, various performance parameters of the engine were measured. From the study it was found tha...

Organic Flash Cycle (OFC) has potential of improving efficiency for recovery of low temperature heat sources mainly due to reducing temperature mismatch in the heat exchanger. In this work exergetical performance analysis of ORC is conducted for recovery of low grade heat source. Effects of system parameters such as flash evaporation temperature or heating temperature are theoretically investig...

in this paper, a hybrid solid oxide fuel cell (sofc) and micro gas turbine (mgt) power system is parametrically studied to evaluate the effect of different operating conditions. the sofc/mgt power system includes sofc reactor, combustion chamber, compressor and turbine units, and two heat exchangers. the effects of fuel utilization, temperature, and pressure are assessed on performance of the h...