The Improvement of Solar Heating Panel Thermal Efficiency: Parabolic Trough Effect Coupled with Porous Packed Bed

Yeong, W.K., Lai, Y.L., and Foo, J.J., SEGi Review 4(1), 44-55, 2011

The effects of hydrostatic, hydrodynamic, porosity and pressure drop on the heattransfer characteristics of a solar heating panel incorporating a parabolictrough collector (PTC) and porous packed bed are investigated experimentally.The results show that a solar collector installed with only a PTC is able toimprove the thermal absorption of the working fluid. Through the addition of aporous media into parts of the receiver tubes, the thermal efficiency of thecollector can be further enhanced. The heat transfer performance increases withthe decrease in porosity and mass flow rate. It is also found that a porousmedium is able to increase the rate of heat transfer during the transienthydrostatic experiment, whereas the rate of heat transfer remains constant in thehydrodynamic study where non-local-thermal-equilibrium (NLTE) becomesdominant. Lastly, it is critical to form a non-sintered porous packed bed usingparticles with uniform diameters to avoid extra internal pressure losses.

Paper (2011):