I recommend you to purchase 300Rs ticket online in ttd website amd the second thing to do after arriving at Chennai is to go the chennai bus stand and board the available bus ( there is good frequency of busses to Tirupati) but I can't assure you a Volvo or Ac conditioned bus at that time...so if you book 300rs ticket the darshan gets over in max 3-4 hours ..and you can get back to Chennai airport in the same...way you came to Tirupati in bus .
It is possible but will not allow you any time to settle down. You have about 26 hrs to complete the trip and return Chennai Airport. It will take you at least 7-8 hrs of bus travel each side(approx 17 hrs with stoppage time) and another 4 hours for darshan depending at what time and day you start. If its a weekend, it may take you more than that. It's going to be more hectic than you can imagine.