Thermal performance and flow analysis in a brazed plate heat exchanger using MWCNT@water/EG nanofluid

In recent years, the growth of energy consumption and the need to optimize it have drawn the attention of researchers to technologies that can increase the performance of heat transfer devices such as plate heat ex-changers. One of these solutions is the use of nanoparticles in common fluids. Despite the many advantages of MWCNT, not enough attention has been paid to its application in plate heat exchangers. The purpose of this study is to investigate the thermal performance and flow of a brazed plate heat exchanger using MWCNT nanoparticles in the cooling fluid of water/Ethylene glycol. The results of the UV spectrum showed that the concentration of 0.05 wt% nanofluid has the most stability. Therefore, the tests required for the two factors of the volume flow rate of cold fluid and temperature of hot fluid were performed at three levels using the response surface method. The results show that at 55 C temperature of hot fluid and volume flow rate of 23.4 l/min of cold fluid, the convection heat transfer coefficient and the heat transfer rate are increased by 20.97% and 34.3% compared with the base fluid. Also, The Nusselt number, pressure drop, friction factor, and pumping power increased by enhancement of the hot fluid temperature and volume flow rate of cold fluid. These parameters of nanofluid at 23.4 l/min and 55 C compared to base fluid increased by 94.45%, 11.25%, 12.87%, and 11.36%, respectively. This study shows better performance at high temperatures compared to similar studies.

Automated summary

In recent years, researchers have focused on technologies that can improve the performance of heat transfer devices, such as plate heat exchangers, in order to cope with the increasing energy consumption and the need for optimization. One solution is the use of nanoparticles in common fluids. However, there has been insufficient attention given to the application of multi-walled carbon nanotubes (MWCNT) in plate heat exchangers. This study investigates the thermal performance and flow characteristics of a brazed plate heat exchanger using MWCNT nanoparticles in a water/ethylene glycol cooling fluid. The results show that the nanofluid concentration of 0.05 wt% exhibits the highest stability, and at a hot fluid temperature of 55°C and a cold fluid volume flow rate of 23.4 l/min, the convection heat transfer coefficient and heat transfer rate increase by 20.97% and 34.3% compared to the base fluid. The Nusselt number, pressure drop, friction factor, and pumping power also increase with higher hot fluid temperature and cold fluid volume flow rate, with the nanofluid exhibiting increases of 94.45%, 11.25%, 12.87%, and 11.36% respectively compared to the base fluid. This study demonstrates better performance at high temperatures compared to similar studies.