Journal
ENERGY
Volume 261, Issue -, Pages -Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.energy.2022.125269
Keywords
Partial heating SCO2 power cycle; Transcritical; Exhaust gas waste heat recovery; Thermo-economic analysis; Multi-objective optimization
Categories
Funding
- National Natural Science Foundation of China [51906026]
- Dalian High-level Talents Innovation Support Program [2021RQ132]
- Fundamental Research Funds for the Central Universities [3132022224]
- China Postdoctoral Science Foundation [2020M680928]
- Natural Science Foundation of Liaoning Province [2020-BS-067]
- National Key Research and Development Program of China [2019YFE0116400]
- 111 Project [B18009]
Ask authors/readers for more resources
A novel cascade system for onboard engine exhaust gas waste heat recovery is developed and analyzed. The results show that the cascade system improves system thermodynamic performance, total heat recovery efficiency, and multi-objective optimization results.
A novel cascade system, in which the exhaust CO2 residual heat from a partial heating supercritical CO2 (SCO2) power cycle is reclaimed by a transcritical CO2 (TCO2) power cycle, is developed for onboard engine exhaust gas waste heat recovery. Firstly, thermodynamic analysis of the cascade system is carried out with the investigation of pinch points in heat exchangers. Then the influence of the topping cycle on the heat source condition of the bottom cycle is found, and the parametric study of the cascade system is performed from the viewpoint of thermodynamics, economy, and footprint. Further, the system comparison analysis with single-optimization is carried out to prove the superiority of the proposed system. Finally, the three-objective optimization is performed to maximize power output, minimize heat exchanger area per unit power and levelized cost of electricity. The results indicate that by integrating a TCO2 power cycle with the partial heating SCO2 cycle, system thermodynamic performance can increase by 15.35%. The recuperator effectiveness has a great impact on the bottoming cycle heat source temperature. The total heat recovery efficiency of the proposed system is improved by 22.64% and 20.24% respectively, compared with the simple SCO2-TCO2 combined cycle and the recuperative SCO2-TCO2 combined cycle. The multi-objective optimization results of the system performance are 841.84 kW, 0.2028 m(2)/kW, and 7.434 cent/kWh, respectively, with the 136 degrees C discharge temperature of the exhaust gas and 29.26% thermal efficiency. These results confirm the cascade system is attractive to waste heat recovery engineering, especially in space-constrained applications.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available