Experimental study of the solar water heater integrated with shell and finned tube latent heat storage system

摘要

In this work, a new design of shell and finned tube latent heat storage system was designed, constructed and tested when it was integrated with the flat plate solar water heater. This design not only provides large heat transfer area between the storage material and the heat transfer fluid, but also it overcomes the problem of low thermal conductivity of paraffin wax (PW) by dividing it into tens of thin slices. Three configurations of storage techniques were proposed; where water, PW as phase change material (PCM) and both water and PW were used as thermal storage materials. The proposed systems were tested at different mass flow rates of heat transfer fluid (0.08-0.16 kg/s). The experimental results showed that the highest daily efficiency of 65% was achieved when the configuration that combines the PCM and water storage tank was used. Moreover, this configuration was capable of providing hot water of temperature ranging from 50 to 60.4 degrees C through 24 h/day. The results of this configuration showed also that the released energy from PW constitutes 52% of the total stored energy; while the remaining energy of 48% was considered backup stored energy that may help in any sudden thermal loads during night.