The thermodynamic performance analysis of SAH with and without storage unit were conducted at Madurai City in India on two consecutive sunny days of May 29 and 30, 2015. Both the SAHs were fabricated with similar dimensions and simultaneously tested in the same location. The tests were carried out during the sunshine hours, from 10:00 AM to 06:00 PM IST. Both the collectors were inclined at an angle of 13$degree$, facing south side according to the geographic location of Madurai.
The inlet and outlet air temperature, ambient temperature, top and bottom of collector surface temperatures were measured at different state points using K-type thermocouples. The data were recorded for every 15 minutes by 34972A Agilent data logger and stored …show more content…
Its $1^{st}$ law efficiency is calculated as 56.80\% at 10:00 hours and attained its first peak value of 59.02\% at 14:00 hours whereas second law efficiency found to be 23.41\% at 10:00 hr and increased to its first peak value of 26.01\% at 14:00 hours. Both the efficiencies increase steeply with the decrease in the solar insolation after 16:00 hours and shows smoother characteristics. It is because of the integrated thermal storage which supplied a part of stored thermal energy to the working medium and atmosphere in order to attain thermal …show more content…
Its $2^{nd}$ law efficiency varied from 11\% to its first maximum of 12\% at 14:00 hours. Cref{fig:Graph-Efficiency-Type2-Jun3} shows the $1^{st}$ law of efficiency varied from 44.39\% at 10:00 hr to its first maximum value of 54.28\% at 14:00 hr whereas the $2^{nd}$ law efficiency varied from 19.34\% to its first maximum value of 24.05\% at 14:00 hr.
The change in enthalpy ($vartriangle$h) and entropy ($vartriangle$S) with respect to time for both the SAHs tested under two different mass-flow rates are calculated and presented in the graphs, cref{fig:Graph-Enthalpy-Jun2} and cref{fig:Graph-Enthalpy-Jun3}. The change in enthalpy helps in understanding the amount of heat energy evolved from the heat exchange process whereas change in entropy helps in understanding the amount of energy lost due to irreversibility at each stage of the operation. In case of SAH, $vartriangle$h is computed based on specific heat capacity and temperature of air at inlet and outlet and $vartriangle$S is computed based on the temperature and pressure changes at inlet and outlet of SAHs. The value of $vartriangle$h for type-I system is varied from 10.35 to 15.48 kJ/kg for $dot{m}$=0.018 kg/s, and 5.82 to 16.80 kJ/kg for $dot{m}$=0.026 kg/s, during the experimental time interval of 10:00 hr to 16:00
The inlet and outlet air temperature, ambient temperature, top and bottom of collector surface temperatures were measured at different state points using K-type thermocouples. The data were recorded for every 15 minutes by 34972A Agilent data logger and stored …show more content…
Its $1^{st}$ law efficiency is calculated as 56.80\% at 10:00 hours and attained its first peak value of 59.02\% at 14:00 hours whereas second law efficiency found to be 23.41\% at 10:00 hr and increased to its first peak value of 26.01\% at 14:00 hours. Both the efficiencies increase steeply with the decrease in the solar insolation after 16:00 hours and shows smoother characteristics. It is because of the integrated thermal storage which supplied a part of stored thermal energy to the working medium and atmosphere in order to attain thermal …show more content…
Its $2^{nd}$ law efficiency varied from 11\% to its first maximum of 12\% at 14:00 hours. Cref{fig:Graph-Efficiency-Type2-Jun3} shows the $1^{st}$ law of efficiency varied from 44.39\% at 10:00 hr to its first maximum value of 54.28\% at 14:00 hr whereas the $2^{nd}$ law efficiency varied from 19.34\% to its first maximum value of 24.05\% at 14:00 hr.
The change in enthalpy ($vartriangle$h) and entropy ($vartriangle$S) with respect to time for both the SAHs tested under two different mass-flow rates are calculated and presented in the graphs, cref{fig:Graph-Enthalpy-Jun2} and cref{fig:Graph-Enthalpy-Jun3}. The change in enthalpy helps in understanding the amount of heat energy evolved from the heat exchange process whereas change in entropy helps in understanding the amount of energy lost due to irreversibility at each stage of the operation. In case of SAH, $vartriangle$h is computed based on specific heat capacity and temperature of air at inlet and outlet and $vartriangle$S is computed based on the temperature and pressure changes at inlet and outlet of SAHs. The value of $vartriangle$h for type-I system is varied from 10.35 to 15.48 kJ/kg for $dot{m}$=0.018 kg/s, and 5.82 to 16.80 kJ/kg for $dot{m}$=0.026 kg/s, during the experimental time interval of 10:00 hr to 16:00