A study on correlation of solar radiation and energy collected from the evacuated tube solar heating system

Observation of the solar radiation phenomena were conducted and successfully gave some important information. In the experiment, fluctuation of solar radiation is quantified. This was mostly influenced by sun brightness; meanwhile ambient air temperature gave small effect for this. From data gotten during the experiment, heat energy collected has unique relation with solar radiation. Although those are proportional but the energy collected takes time to follow the solar radiation changes. This phenomenon makes the maximum value of those two parameters are occurred at different time. The experiment was conducted for 2.5, 3, 5 and 6 liter per minute of water flow, by using two units of solar collector. And the result showed higher flow of water lower temperature difference of outlet and inlet. So the optimum value of water flow can be determined by considering that total energy collected in one day for each flow rate are same. The total energy produced by the system can be calculated numerically by measuring the area below a curve in the energy collected to time graph. Then estimation of solar collector number, in order to fulfill precise amount of energy, can be done. This result will be importantly used for the application which needs specified quantity of energy.