A refresh does not affect any request or Session scope variables. A refresh might not be idempotent(by HTTP standards POST is not Idempotent but your implementation might be) if you are using a POST method to send data back to the server.
The request variables do not go out of scope on a refresh as the data being requested from the server on each refresh is the same as the one that was sent in the first request.
One request will (probably) send a response back to the browser. The others will find that the browser is no longer interested in any response and get an exception something like connection reset by peer. My Wiki server handled this poorly for a while and banging on refresh was a good way to blow out the stack and write megabytes of log files.
A good question is never answered. It is not a bolt to be tightened into place but a seed to be planted and to bear more seed toward the hope of greening the landscape of the idea. John Ciardi
Refresh behaviour also depends on the browser being used. I feel Firefox handles this very nicely. It would queue up all the requests. In case of IE it fires two(or more) seperate requests at the same time.
subject: What happens if multiple refresh requests are sent?