Surface Modification of Carbon Nanotube Nanofluids for Higher Thermal Efficacy of Plate and Shell and Tube Heat Exchangers

Due to the special physical and chemical properties of Carbon NanoTubes (CNT), surface modification was utilized to improve the thermal characteristics of nanofluids. These techniques were done by physical and chemical modification of CNTs and utilized as a thermal fluid in plate and shell and tube heat exchangers. Polyethylene glycol (PEG) wrapping and acid treatment were respectively applied as physical and chemical procedures on the surface of CNTs to improve the dispensability of nanotubes in the base fluid. Results show the better dispersion and stability of these nanoparticles in water and consequently higher thermal conductivity of nanofluids. The thermo-physical properties of these nanofluids were applied as input variables to simulate the plate and shell and tube heat exchangers. The thermal power results of simulated heat exchangers show the higher efficiency of nanofluids compared to the base fluid. This result can be useful to enhance the thermal efficacy of heat exchangers in various industries, especially in oil, gas, and petrochemical industries.