Be careful while selecting time step size. One major problem in such simulations is the computational time involved. You need to select a very low time step in order to maintain the Courant number within permissible limits. Also, you need to take special care while specifying material properties as you are dealing with nanofluid.

thanks for answering Mr. Uday Raj it is my pleasure to hear from you.

I think you can used VOF model to simulate the boiling process ..I think the VOF approach is easier to converging the simulation.