CPOTE2022
7th International Conference on
Contemporary Problems of Thermal Engineering
Hybrid event, Warsaw | 20-23 September 2022
7th International Conference on
Contemporary Problems of Thermal Engineering
Hybrid event, Warsaw | 20-23 September 2022
Abstract CPOTE2022-1052-A
Book of abstracts draft
Assessment, optimisation and working fluid comparison of organic Rankine cycle combined with negative CO2 gas power plant system
Kamil STASIAK, Gdansk University of Technology, PolandPaweł ZIÓŁKOWSKI, Gdańsk University of Technology, Poland
Dariusz MIKIELEWICZ, Gdańsk University of Technology, Poland
This study aims to investigate the application of the Organic Rankine Cycle (ORC) as an alternative to low-pressure expansion in the negative CO2 power plant (nCO2PP). The reason for this study is that a detailed analysis of nCO2PP indicates a certain amount of waste heat present in the exhaust gas from the high-to-intermediate pressure gas turbine. Some of this energy can be used by the application of the expansion in a low-pressure turbine, optionally the application of regenerative water heating, which is further directed to the combustion chamber, and alternatively the combination of the ORC into the main cycle. For the ORC cycle, various configurations are examined, either with or without regenerative water heating and using different working mediums. For the highest cycle efficiency, regenerative heating of high-pressure water is applied, and proper ORC working fluid with optimum saturation point and mass flow is selected. Such modified nCO2PP power plant hybrid systems with ORC are compared to the original concept of nCO2PP with lower pressure expansion. A hybrid system integrating the advantages of nCO2PP and an ORC cycle is a promising solution, and modifications are possible, but the main advantage is that an ORC cycle can be introduced as a component to provide electrical power in the lower temperature range. Three ORC mediums were calculated, namely ethanol, refrigerants R236-ea and R245-fa which yielded net efficiency of the whole power plant of 38.35%, 40.16% and 40.39% respectively, while the original nCO2PP yielded 38.89%.
Keywords: Organic Rankine cycle (ORC), Waste heat recovery, Hybrid power plant, Negative CO2 gas Power Plant (nCO2PP), Efficiency enhancement
Acknowledgment: The research leading to these results has received funding from the Norway Grants 2014-2021 via the National Centre for Research and Development. This research has been prepared within the frame of the project: "Negative CO2 emission gas power plant” - NOR/POLNORCCS/NEGATIVE-CO2-PP/0009/2019-00 which is co-financed by programme “Applied research” under the Norwegian Financial Mechanisms 2014-2021 POLNOR CCS 2019 - Development of CO2 capture solutions integrated in power and industry processes.