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...

A mathematical model for computing the thermal performance of an air heater with a truncated compound parabolic concentrator having a flat one-sided absorber is presented. A computer code that employs an iterative solution procedure is constructed to solve the governing energy equations and to estimate the performance parameters of the collector. The effects of the air mass flow rate, the wind ...

Solar air heater is a type of heat exchanger which transforms solar radiation into heat energy. The thermal performance of conventional solar air heater has been found to be poor because of the low convective heat transfer coefficient from the absorber plate to the air. It is attributed to the formation of a very thin boundary layer at the absorber plate surface commonly known as viscous sub-la...

In this paper double flow packed bed solar air heater has been investigated theoretically. The effect of air mass flow rate, porosity and different depth ratios at study state conditions on the thermal performance of a double flow packed bed solar air heater is found by using the alternative simulation system. Comparisons between the measured thermal and effective thermal efficiency of the doub...

this work presents the heat transfer characteristics of a new type of porous radiant air heater that operates on the basis of effective energy conversion method between flowing gas enthalpy and thermal radiation. at each layer, the gas and solid phases are considered in non-local thermal equilibrium, and combustion in the porous radiant burner is modeled by considering a non-uniform heat genera...

In this article, a numerical investigation is conducted to analyze the two-dimensional incompressible Navier–Stokes flows through the artificially roughened solar air heater for relevant Reynolds number ranges from 3800 to 18,000. Twelve different configurations of equilateral triangular sectioned rib (P/e = 7.14–35.71 and e/d = 0.021–0.042) have been used as roughness element. The governing eq...

Based on an effective energy conversion method between gas enthalpy and thermal radiation, a multi-layered type of porous air heater has been proposed. In the five layered structure which is analyzed in this work, there are five porous layers which are separated by four quartz glass windows. The main layer operates as a porous radiant burner that products a large amount of thermal radiative ene...

An optimal combination of the characteristics of an air conditioning system and the control strategy is necessary to minimize costs and the energy demand. Therefore a sequential control for such a system was developed, tested by simulation and implemented in an existing plant. The simulation runs have been done with TRNSYS [1],[2]. For the sake of comparison, an optimized control was calculated...