Abstract
Since solar energy is unstable during the day, storage energy is essential to use this energy effectively. An experimental study on a newly designed, integrated solar collector with Nano enhanced-PCM-based energy storage has been carried out for solar collector application at night or when solar radiation is unstable. Before the collector design, performing a performance analysis on three different Nano-enhanced PCM was performed to select the nano-based PCM. To investigate the improvement in energy absorption performance, charging and discharging tests are performed at different flow rates. Amine functionalized paraffin wax (f-NH2-MWCNTs + PW)PCM has been selected due to high thermal conductivity and higher enthalpy gain among four samples, MWCNTS + PW, f-OH-MWCNTS + PW, and f-COOH-MWCNTS + PW. Finned triangular shape container designed for encapsulation of hybrid PCM, f-NH2-MWCNTs + PW. Fourteen triangular shape containers with rectangular profile fins are designed for PCM storage. PCM module has attached to the bottom of the trapezoidal absorber plate of the flat plate solar collector (FPSC). Experimental observation of charging and discharging shows that 21 % decrease in charging time while a 23 % decrease in discharging time observed for f-NH2-MWCNTs + PW compared to pure PCM, at 0.1 % particle volume concentration, flow rate 2.25 LPM and solar intensity 1010 W/m2. Instantaneous charging and discharging efficiencies are enhanced by 24 % and 28 %, respectively, compared to base PW PCM. Overall exergy gain for PCM enhanced system with respect to base FPSC is 12 %.The innovative design NePCM encapsulation and its attachment with the bottom of the trapezoidal absorber plate to utilize excess thermal energy that may go as waste through bottom insulation makes this work distinctive from past and contemporary research. This investigation aims to enhance energy utilization by storing excess amounts in the attached PCM storage. This system can be used for off-time hot water supply and milk pasteurization applications.
•f-NH2 MWCNT + Paraffin Wax material used for energy storage•Triangular shaped contentment design with rectangular fins of copper adopted•Dimensionless temperature versus Stefan number graphs analyzed•Ne-PCM module shows higher energy and exergy efficiency.•Charging and discharging efficiencies increase for Ne-PCM module.