What is the ruling on me saying "you are divorced" to myself with the intention of effecting a divorce in the future when my wife is angry, knowing that I do not intend to divorce her now?

An explicit pronouncement of divorce takes effect even without the intention (of divorce). However, your saying "You are divorced" while imagining what your wife might do in the future does not constitute a divorce, as long as you did not intend to effect the divorce at that very moment. Therefore, the marital bond remains, and no divorce has taken place.