Can or will someone be going with you? If someone is with you maybe that would help be a buffer between you and him. If he approaches you, I would firmly tell him that you do not wish to speak with him and not to approach you again.
If he persists, then I would seek out a security person.
Be firm and stay strong. If he is inappropriate or confrontational, call him out on it. Enlist the help of people around you, don't let him intimidate you.