Performance reseach on water cooler with silicon nitride/polyolester nanolubricant

Abstract

Performance of vapour compression refrigeration depends on refrigeration effect and power utilization of the compressor. The present work focuses on reduction in power utilization of the compressor and enhancement in refrigeration effect with the supplement of silicon nitride (Si3N4) nanoparticles (NP) to the compressor lubricant polyolester (POE) oil. Also the performance of the water cooler has been compared with the addition of tetra butyl ammonia iodide (TBAI) surfactant to the nanolubricant. Thermophysical properties of the modified POE and POE/Si3N4NP/surfactant were found before experimentation to select the optimum concentration for the performance evaluation. Test results showed that the maximum thermal conductivity was improved by 31.06% for nanolubricant and 30.5% for nanolubricant with surfactant at 0.6% vol concentration. It is also seen that the viscosity has been enhanced maximum at 0.6% vol. concentration and for the same concentration the friction coefficient has been reduced by 7% and 11% for nanolubricant and nanolubricant with surfactant. Further the performance was evaluated with nanolubricant and nanolubricant/surfactant and the results were compared. It is found that the coefficient of performance (COP) has been enhanced by 36.39% and 29.6% for nanolubricant and nanolubricant/surfactant. Also the performance of the water cooler was investigated after 30 days and the results were in accordance with the initial results. Hence the experimentation shows that the addition of Si3N4 nanoadditives to the POE oil enhances the working of the water cooler.