how to schedule saved search to run and email results every 30 mins

To the best of my knowledge, this isn’t possible to do. You’d need to run a scheduled script which generates and emails the search – or create a restlet and trigger it from an external cron process or similar.

I’d also have to question the business case for this, whether the amount of processing involved is significant when run this frequently and whether it may affect system performance.

It may be better to create the saved search and add it to a user’s dashboard as a Custom Search, so it can be viewed easily and refreshed on demand when needed.