Experimental Study on the Performance of RT 25 to be Used as Ambient Energy Storage

The proposed experimental work intends to analyse the thermal performance of a TES unit incorporated into a ventilation system under different working conditions. The influences of the air inlet temperature and velocity on the air outlet temperature and heat transfer rate were investigated The air inlet temperature used for the solidification of RT25 were 10 °C, 12 °C and 14 °C and for the melting 34 °C, 36 °C and 38 °C. The selected air inlet velocities were the same for the melting and solidification process: 0.5 m/s, 1.4 m/s and 2.5 m/s. The results suggest that an increase of the air inlet velocity reduces linearly the temperature difference between the air inlet and outlet for the solidification process of the RT25. Contrary, for the melting of the RT25, increasing the air inlet velocity does not reduce the temperature difference linearly, increasing the air inlet temperature furthermore from 36 °C to 38 °C did not affect the melting time. The air inlet temperature plays a significant role on the melting process, reducing linearly the air inlet and outlet temperature difference and the heat transfer rate, however does not influence the solidification process, similar air inlet and outlet temperature difference and the heat transfer rate were obtained for all condition.Thus, air inlet velocity and air inlet temperature have to be carefully balanced to optimize the whole running cycle of both melting and solidification processes.