RETRACTED: Modernization of existing infrastructure, heat supply systemsParviz Khujaev, Zokhidjon Abdulkhaev, Shohkzodbek Numonjonov, Nematulla Karimov and Kambarali AkhunovE3S Web Conf., 538 (2024) 01010DOI: https://doi.org/10.1051/e3sconf/202453801010