My objective is to simulate the Phase Change process in water as it solidifies to Ice when it exchanges heat with Refrigerant R-22 passing within a copper tube carrying the refrigerant. Ice formation takes place around the copper tube. The 2D model with the defined conditions has been attached herewith. I am using COMSOL Mutilphysics 5.2 for the simulation purpose. I am unable to get the desired heat exchange result with the given boundary conditions. Kindly someone with working knowledge of simulating heat transfer and fluid flow help me out with this problem.