Heat transfer intensification in a LFR unit considering exergy analysis of radiative and convective mechanism

In current solar unit, mirrors with involve of parabolic secondary reflector has been employed to enhance the absorbed radiation flux. The optical efficiency with involve of modified secondary reflector augments about 21%. The absorbed flux profile was added in energy equations as source term and three dimensional turbulent flows have been analyzed. Bottom of the pipe facing with mirrors has greatest radiation flux and its value is 7500 W/ m(2). The top point of pipe has higher radiation flux than left and right sides because of presence of secondary reflector. Water as base fluid inside the pipe was mixed with Al2O3. Besides, install of fins has been considered as second approach to help the thermal performance. With increase of fin length and Re, swirl flow enhances and superior cooling obtains which offers thinner boundary layer. At highest values of other factors, growth of Re leads to 0.43% reduction in temperature while rise of T-in makes temperature to augment about 9.97%. The value of eta(ex) for T-in = 323.15 is 97.43 times greater than that of T-in = 298.15 when Re = 8000 and t = 0. With select of highest values of Re and lowest values of T-in, the finned tube (t = 3 mm) has greatest thermal efficiency.