Experimental Investigation of Thermal Performance of Engine Coolant Oil and Water in Helical Coil Heat Exchanger

摘要

A comparative thermal analysis of water and engine coolant oil in a helical coil tube and shell heat exchanger is performed. The experimental study is carried out in parallel and counter flow conditions with laminar flow of the fluids. Various factors like heat transfer coefficient, friction factor, pressure drop and pumping power for different fluid flow rates of 0.25 lpm (liter per minute), 0.5 lpm and 0.75 lpm along tube side and shell side are compared. The other common factors of the heat exchanger along tube and shell side like overall heat transfer coefficient, NTU (Number of Transfer Units), LMTD (Log Mean Temperature Difference), effectiveness and average heat transfer are also analyzed for variation in flow rates. The variation of overall heat transfer coefficient is also compared with different non-dimensional numbers such as He (Helical Number), De (Dean Number), LMTD and NTU. The maximum enhancement % of various heat transfer characteristics comparative to water in parallel flow condition is provided. For coolant oil counter flow the average heat transfer is enhanced by 63.3%, convective heat transfer coefficient by 42.7% and overall heat transfer coefficient by 98.9% compared to parallel flow of water. It is also observed that counter flow of water provides more enhanced heat transfer (18.7%) than parallel flow of coolant oil.?