Experimental Study on a Solar Water Heater Using Supercritical Carbon Dioxide as Working Fluid

In this paper, a solar water heater using supercritical carbon dioxide as working fluid is experimentally studied. The sloar water heater is based on a natural convective supercritical CO₂ flow. In the present study, an experimental set-up is designed and tested in order to obtain a basic knowledge on this solar water heater. The obtained results show that the natural convective flow is well induced even in winter, the lowest level of solar radiation condition. Furthermore, collector efficiency is measured at above 86.0%. More theoretical investigations are needed to be carried out to make clear about its mechanism etc.