can i hook a 52" projection tv to a computer

Should be able to, though it might not be such a good idea. Static images on a pc might burn into the screen if you leave it on for too long. I used my old mitsubishi 55inch old school hdtv to play oblivion on my pc at 1080i way back, looked okay for being old tech. If you have a newer one you'll have a much easier time than I had hooking it up.
 
hmm dont think burn in is mcuh of an issue these days with LCD or rear projection.

also it might be fine for games, but thats it, to use this as a desktop wont be great and hear is why. a 30" monitor is 2500*1600 resolution, the most that TV is going to be is 1080 which is no where near. and it is 22" bigger so your pixel per inch isnt going to e great either.

now if your still ok with that, then assuming you have a HDMI port on your TV all you will need is a HDMI to DVi connector. or perhap your TV might have VGA or DVI already on it.
 
newer projection tv's do have anti-burn in features, so as long as it was bought in the past two years, and is from a reputable company, than you should be fine