TY - CPAPER AB - © 2016 University of Ljubljana. Organic Rankine cycle (ORC) power systems are being increasingly deployed for waste heat recovery and conversion to power in several industrial settings. In the present paper, we investigate the deployment of working-fluid mixtures in ORCs operating in combined heat and power mode (ORC-CHP) with shaft power provided by the expanding working fluid and heating provided by the cooling-water exiting the ORC condenser. Using the flue gas from a refinery boiler as the waste-heat source and with working fluids comprising normal alkanes, refrigerants and their subsequent mixtures, the ORC-CHP system is demonstrated as being capable of delivering over 20 MW of net shaft power and up to 15 MW of heating, leading to a fuel energy savings ratio (FESR) in excess of 20%. Single-component working fluids such as pentane appear to be optimal at low hot-water supply temperatures. Working-fluid mixtures become optimal at higher temperatures, with the working-fluid mixture combination of octane and pentane giving an ORC-CHP system design with the highest efficiency. AU - Oyewunmi,OA AU - Kirmse,CJW AU - Markides,CN PY - 2016/// TI - Performance of working-fluid mixtures in an ORC-CHP system for waste-heat recovery ER -