How many litter pans do you have, and is he your only cat?
The first thing I would do is to have your kitty examined to make sure he doesn't have a urinary tract infection. There is no set number of times a day that a cat urinates, they are all different. However, cats that have infections will urinate very frequently through out the day. Here is a link to a page about urinary tract disease:
If a medical problem is ruled out there are some things you can try. First off, since you only have one litter pan, I would add at least one more. If you have to line them up in row that's fine. Many cats will prefer to defecate in one, and urinate in the other. It is fairly common for a cat that has been fine for years to suddenly start going in inappropriate places. No matter what the reason this just gives them more appropriate options. A good rule of thumb is one more pan than the number of cats you have. Also, I would make sure that you have at least one covered pan, and one without a cover. Next I would put different types of litter in the pans. There's clumping or clay, some are made from corn, wheat, newspaper, or any number of substances. Some cats will prefer one type to another. If you have ever cleaned the litter pan with an actual cleaner rinse it out with plain water. Many cats will not use a pan that has had any type of chemical cleaner used in it. Another thing you can try is a product called Feliway. It consists of calming pheromones, and comes in either a plug in diffuser or a spray form. The spray is put directly on the locations where he has urinated to keep him from going there again. The diffuser spreads throughout the house, but is odorless to humans. Feliway was specifically designed for cats that eliminate in inappropriate places. It can be purchased in most pet stores or on-line. Here is a link to their website:
http://www.feliway.com/gbClean anyplace that he has urinated with an enzyme cleaner. They get rid of odor better than other cleaners. Nature's Miracle is a good one. Here is a link to a page that may have some additional ideas for you: http://www.peteducation.com/article.cfm?c=1+2174&aid=158 If you have further questions let me know. If this answer is helpful please click accept. Thank you. Lynn