Heat Pipe Evacuated Tubular Solar Collector Performance Improvement By Applications of Nanofluid

There are many different type of solar energy systems, which are being used widely for different applications. the most important element of these solar systems is solar collector. there are four main types: flat panel (fpsc), evacuated tube, heat pipe and parabolic. the most popular type is fp, which was invented in 1950s and this type is predominantly used for last three decades not only in residential but also industrial areas. this is because of two main factors: low initial investment and easy usage. efficiency of fpscs are mainly effected by 3 parameters: working fluid thermal conductivity, heat losses and optical losses. due to low efficiency of fpscs, evacuated tubular heat pipe solar collectors (etscs) are now being studied to replace fpscs. in this type of solar collectors, optical and thermal losses are minimized and performance of the system is better. in this study, etscs which are tested by charging nano fluid were studied and these researches are very limited in the literature. last studies proved that nano fluids are increasing thermal efficiency especially in heat pipes. the outcomes from this study shows that using nano fluids in etscs provides following benefits: low thermal resistance, high thermal conductivity, higher working temperatures, acceleration in reaching working temperature and improvement in efficiency.