Main content area

Experimental investigation of heat removal factor in solar flat plate collector for various flow configurations

Malvi, C. S., Gupta, Arpit, Gaur, M. K., Crook, R., Dixon-Hardy, D. W.
International journal of green energy 2017 v.14 no.4 pp. 442-448
equations, heat transfer, mass flow, melting, melting point, serpentine
This paper reports the performance of a solar flat plate collector for various flow configurations and presents a comparative evaluation. Three cases have been discussed: (i) serpentine flow, (ii) parallel-wall-to-wall flow, and (iii) spiral flow. The heat removal factor (F R) is the ratio of the actual heat transfer to the maximum possible heat transfer through the collector plate. A special case showing the effect of phase change material (PCM) on F R in the case of serpentine is discussed. A sheet-and-tube type collector where the tubes are bonded to the absorber plate by a suitable adhesive is considered. Equations showing the dependence of F R on the fin factor were studied and indoor experiments were conducted to determine the value of F R. Finally, a numerical investigation was done and comparisons were evaluated. Results indicate that when the mass flow rate () of water is 1, the value of F R for serpentine and parallel wall-to-wall flow is 0.44 and 0.88, respectively. It was also observed that for the case of PCM, F R is a variable quantity and its value ranges from 0 to 0.28. In this case, F R is a function of the PCM melting and solidifying phases rather than mass flow and is proportional to the melting temperature of the PCM. Also, it is observed that in a conventional water heater with serpentine flow or parallel wall-to-wall flow, the value of F R does not increase significantly beyond a mass flow rate () of 4 kg/hr.