Analysis of the thermodynamic performance of transcritical CO2 power cycle configurations for low grade waste heat recovery

Organic Rankine cycles employing carbon dioxide (CO2) for waste heat recovery became popular in the last years thanks to its excellent transfer characteristics and small environmental footprint. Low-grade (<240 °C) represents major portion of excess globally, but it is hard recover due temperature gap source sink leading a poor efficiency cycle. Therefore, numerous modifications power cycle layout were proposed by academia industry — reheated expansion, recuperation intercooled compression among them. This work compares ten architectures defined (60–100 (20 °C). Firstly, CO2 from literature are examined with original operational parameters. Secondly, predefined low-grade implemented into The assessed regarding efficiency, mass flow pressure. Results show that temperatures higher than 80 °C, expansion enhance performance whereas negatively affects efficiency. conventional configuration operated most efficiently until °C. A road map thermodynamic efficiencies up 100 °C delivered.