Measurement of local wall heat transfer coefficient in randomly packed beds of uniform sized spheres using infrared thermography (IR) and water as working medium

In the present work, the local wall heat transfer coefficient is estimated from local wall temperature data obtained using infrared (IR) thermography for the packed beds with randomized packing of uniformly sized spheres under steady state conditions with water as the working fluid. The experiments are conducted for bed to particle diameter ratios of 6, 3 and 2 using random packing of mono-dispersed glass spheres. The two-layer model theory for heat transfer in packed beds is examined in terms of contribution or core zone and wall zone in packed beds. The comparison of heat transfer enhancement aspects with different insert configurations is done and packed beds are found effective.