A thermofluid temperature modeling, prediction of closed-loop cooling system of roll grinder based on circulation differential equations

Abstract

Roll grinders are essential in high-precision roll manufacturing. However, lubricant temperature fluctuations decrease the precision of grinders. The complicated dynamic heat transfer within the closed-loop cooling systems of roll grinders poses significant challenges to accurately modeling their thermal states. This study proposed a novel model based on circulation differential equations for the thermofluid temperatures in roll grinders. Based on thermodynamic principles, differential equations of each component within the closed-loop cooling system were derived. To improve model accuracy, a thermal resistance approach was utilized, and the thermal interaction between lubricant and hydrodynamic bearings under different speeds and the heat convection between hydraulic hoses and air are considered. To validate the proposed model, a series of experiments across a range of spindle speeds were carried out. The results showed the model could achieve prediction accuracy less than 5.27%. Subsequently, the influence of system design parameters on cooling performance was analyzed. The proposed temperature model better comprehends the thermodynamic interaction within closed-loop cooling systems featuring hydrodynamic bearings. The limitations and potential application in other industrial areas were discussed.