The Capital Region Development Authority will shortly launch $20 million in repairs and upgrades to the XL Center, Hartford’s premier sports arena and convention center. Michael Freimuth, executive director of the CRDA, told his board in a Thursday meeting the funding will come from a $40 million pool of state bond money the agency received “several years ago.” Right now, CRDA estimates $15 million to $20 million for this work. Freimuth expects firmer numbers after the return of bids that will be released over the next few months. The CRDA has hired Providence-based Dimeo Construction to manage the project. Freimuth previously said he hopes to have the sports betting facility ready to open in September. The entire plan, however, hinges on ongoing negotiations with state officials over a split of betting proceeds, Freimuth said.