Page is on your browser - which has no direct link to the web-server where the application is deployed. It won't refresh by-itself after web.config changes at server. when you change the web.config then on server the application re-cycles. You will lose session in that case - but as long as you don't do anything your page will remain as it is.
For continuous refresh you can write some client side scripting where after every few seconds you can force your page or a portion of it to re-load. Something like cricket scores.
You could register something like following in your onload event.
This link you can go through.