Numerical Investigation on Critical Velocity of Ice Slurry Flow

Abstract

The use of ice slurry as a working fluid in secondary-loop of refrigeration system not only enhances the system performance but also reduces the refrigerant charge and its leakage to environment. It can be transported through pipes; however, flow of ice slurry is a quite complex two phase flow, which significantly differs from conventional fluid flow. Ice slurry flow can be influenced by on several operating parameter viz. initial velocity, ice concentration, freezing point depressant concentration and particle size. Solution of such type of flow through pipe is a difficult task through experiments due to complexities in visualization and measurements. Therefore, a CFD model is developed to simulate the ice slurry flow to predict the safe conditions for the transportation of ice slurry. In the present work, numerical investigation of flow of ice slurry has been analyzed in order to predict the critical velocity and effect of different parameters on critical velocity. Eulerian granular flow model has been used for the simulation, which is also validated with existing experimental results in the literature. Result shows that, the critical velocity is especially influenced by the particle size. Critical velocity at 10 % initial ice concentration increases from 0.4 m/s to 0.16 m/s with increase in particle size from 0.1 mm to 0.4 mm.