PERFORMANCE ENHANCEMENT OF TWO PHASE THERMOSYPHON FLAT-PLATE SOLAR COLLECTORS BY USING SURFACTANT AND NANOFLUID

In this study the thermal performance of three different wickless heat pipe solar collectors were investigated by using pure water, watersurfactant and CNT-water nanofluid for different coolant mass flow rates and tilt angles (20 0 , 31.5 0 , 40 0 , 50 0 and 60 0 ). First collector uses only pure water, the second one utilizes CNT nanoparticle of diameter 10-12 nm and 0.1-10 μm length with water as a base fluid. While the third collector uses water with 150 ppm 2-ethyl-hexanol as coolant for the investigation. Experiments were carried out for the three collectors under the same experimental conditions. It is observed that the performance of the solar collector that uses 2-ethyl-hexanol surfactant with water as coolant is better compared to solar collectors that utilize pure water and CNT/water nanofluid.