Performance Enhancement of Two Phase Thermosyphon Flat-Plate Solar Collectors by Using Surfactant and Nanofluid

Abstract

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.

Two-phase closed thermosyphons: A review of studies and solar applications

“…The experimental results showed that the maximum collector efficiency was about 66%. Chougule et al [114,115] experimentally investigated a TPCT-FPC (d i =10 mm and L=625 mm) using pure water, water-2ethyl-hexanol surfactant and carbon nanotubes and various tilt angles (20-60˚). They showed the maximum efficiency of 73% using nanofluid (30% higher than using pure water) and the system efficiency increases with the tilt angle and decreases when the tilt angle exceeds 50˚.…”

Comparative Study on Heat Transfer Enhancement of Low Volume Concentration of Al2O3–Water and Carbon Nanotube–Water Nanofluids in Laminar Regime Using Helical Screw Tape Inserts

“…In this procedure, hydroxyl and carboxylic groups are inserted on the surface of the nanotubes. Because of the equal charge of these groups CNTs repel from each other leading to the dispersed form of the solution [21][22][23][24][25][26][27][28][29]. On the contrary, Al 2 O 3 -water nanofluid is prepared by simply dispersing specified amounts of nanoparticles in the de-ionized water without addition of any surfactant.…”

“…The acid treatment method essentially introduces hydroxyl group at the surface of CNT leading to conversion of the CNT surface from hydrophobic to hydrophilic. Initially, CNTs were initially immersed in a mixture of H 2 SO 4 /HNO 3 (3:1) at room temperature to break up the winding state [21][22][23][24][25][26][27][28][29]. Later on, CNTs were treated in an ultrasound bath (USBT-9.0L Ultrasonic Cleanser, 200 W, Rico Scientific Industries, India) for 2 h and upheld for 15 h. Further, this solution was neutralized by using ammonium hydroxide and filtered with a 0.22 mm cellulose acetate membrane.…”

Comparative Study of Cooling Performance of Automobile Radiator Using Al2O3-Water and Carbon Nanotube-Water Nanofluid

“…The physical properties of CNT and Al 2 O 3 nanoparticles are listed in Tables 1 and 2. CNT nanofluids with different nanoparticle concentration (/ ¼ 0.15%, 0.45%, 0.60%, and 1%) were prepared by the functionalization acid treatment method [15][16][17][18][19][20]. According to this method, simple acid treatment gives good stability in water to carbon nanotubes suspension.…”