Experimental investigation on the effect of thermophysical properties of a heat transfer fluid on pumping performance for a convective heat transfer system

Pumping performance is crucial for a convective heat transfer system. However, there is a limited study that specifically discusses the relation between thermophysical properties of a Heat Transfer Fluid (HTF) and pumping performance. This study aims to find the effect of the change in thermophysical properties of HTF on the pumping performance, particularly for the delivery rate, slip factor coefficient, and volumetric efficiency. In this study, five different HTFs are used to assess the effect of working temperature and pumping speed on the pumping performance. Delivery rate is evaluated by setting the pumping speed from 0 to 1300 RPM where the working fluid temperature is set at 40, 140, and 200 degrees C. It shows that the HTF with a lower viscosity has a better delivery rate. The slip coefficient for all working fluid is ranging between 0.11-0.31 at temperature 200 degrees C. It is found that a higher working temperature for the fluid increases the slip coefficient and delivery rate. The volumetric efficiency is directly affected by the slip ranging from 69 - 89% at 200 degrees C. The heat transfer rate ranges from 40 - 98 degrees C for all fluids, which is mainly affected by the volumetric efficiency of the pump and also pumping speed where a higher pumping speed decreases the heat transfer rate. It can be concluded that the change in thermophysical properties of the working fluid will change the pumping performance. Therefore, it is important to adjust the pumping operation according to the temperature and properties of the working fluid to achieve the highest heat transfer rate for a convective heat transfer system.