Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGA
(1) Background: the shipping industry forced ships to adopt new energy-saving technologies to improve energy efficiency. With the timing modulation for the marine low-speed diesel engine S-CO<sub>2</sub> Brayton cycle, the waste heat recovery system is optimized to improve fuel economy....
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| Format: | Article |
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MDPI AG
2022-10-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/24/11/1544 |
| _version_ | 1797468353009287168 |
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| author | Liangtao Xie Jianguo Yang |
| author_facet | Liangtao Xie Jianguo Yang |
| author_sort | Liangtao Xie |
| collection | DOAJ |
| description | (1) Background: the shipping industry forced ships to adopt new energy-saving technologies to improve energy efficiency. With the timing modulation for the marine low-speed diesel engine S-CO<sub>2</sub> Brayton cycle, the waste heat recovery system is optimized to improve fuel economy. (2) Methods: with the 6EX340EF marine low-speed diesel engine established in AVL Cruise M and verified by the bench test data, the model of the S-CO<sub>2</sub> Recompression Brayton Cycle (SCRBC) system for the low-speed engine flue gas waste heat recovery was developed in EBSILON, and verified by SANDIA experimental data. On this basis, the effects of injection timing and valve timing parameters on the comprehensive performance of the main engine and the waste heat recovery system were investigated. By optimizing the timing modulation parameters through multi-objective genetic algorithm (MOGA) and evaluating the flue gas waste heat recovery from the perspective of thermodynamic performance and emission reduction, the research on the performance modulation method of the S-CO<sub>2</sub> Brayton Cycle for flue gas waste heat in marine low-speed engines has been completed. (3) Results: the SCRBC with waste heat modulation will further increase the total power and efficiency, which in turn brings about a reduction in the fuel consumption rate. The efficiency of the SCRBC system with the addition of waste heat modulation increases by 2.28%, 1.04% and 2.07% at 50%, 75% and 100%, respectively. After adding the residual heat modulation, the maximum annual CO<sub>2</sub> emission reduction of 748.51 × 10<sup>3</sup> kg·a<sup>−1</sup> occurred at 50% load; with the exergy analysis, the cooler has the largest system exergy loss of 165 kW, with the exergy loss efficiency of 2.06% under 100% load. (4) Conclusions: the research on the performance modulation method of S-CO<sub>2</sub> Brayton cycle for flue gas waste heat in the marine low-speed engine has been completed, which further improves the efficiency of the system and can be extended to other engines. |
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| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-03-09T19:05:15Z |
| publishDate | 2022-10-01 |
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| spelling | doaj.art-39b986cbce9444af87e34eb9b193fbf02023-11-24T04:35:59ZengMDPI AGEntropy1099-43002022-10-012411154410.3390/e24111544Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGALiangtao Xie0Jianguo Yang1School of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology, Wuhan 430063, ChinaSchool of Naval Architecture, Ocean and Energy Power Engineering, Wuhan University of Technology, Wuhan 430063, China(1) Background: the shipping industry forced ships to adopt new energy-saving technologies to improve energy efficiency. With the timing modulation for the marine low-speed diesel engine S-CO<sub>2</sub> Brayton cycle, the waste heat recovery system is optimized to improve fuel economy. (2) Methods: with the 6EX340EF marine low-speed diesel engine established in AVL Cruise M and verified by the bench test data, the model of the S-CO<sub>2</sub> Recompression Brayton Cycle (SCRBC) system for the low-speed engine flue gas waste heat recovery was developed in EBSILON, and verified by SANDIA experimental data. On this basis, the effects of injection timing and valve timing parameters on the comprehensive performance of the main engine and the waste heat recovery system were investigated. By optimizing the timing modulation parameters through multi-objective genetic algorithm (MOGA) and evaluating the flue gas waste heat recovery from the perspective of thermodynamic performance and emission reduction, the research on the performance modulation method of the S-CO<sub>2</sub> Brayton Cycle for flue gas waste heat in marine low-speed engines has been completed. (3) Results: the SCRBC with waste heat modulation will further increase the total power and efficiency, which in turn brings about a reduction in the fuel consumption rate. The efficiency of the SCRBC system with the addition of waste heat modulation increases by 2.28%, 1.04% and 2.07% at 50%, 75% and 100%, respectively. After adding the residual heat modulation, the maximum annual CO<sub>2</sub> emission reduction of 748.51 × 10<sup>3</sup> kg·a<sup>−1</sup> occurred at 50% load; with the exergy analysis, the cooler has the largest system exergy loss of 165 kW, with the exergy loss efficiency of 2.06% under 100% load. (4) Conclusions: the research on the performance modulation method of S-CO<sub>2</sub> Brayton cycle for flue gas waste heat in the marine low-speed engine has been completed, which further improves the efficiency of the system and can be extended to other engines.https://www.mdpi.com/1099-4300/24/11/1544marine low-speed diesel enginewaste heat recovery of flue gasS-CO<sub>2</sub> recompression Brayton cyclewaste heat modulationthermodynamic performancethe exergy analysis |
| spellingShingle | Liangtao Xie Jianguo Yang Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGA Entropy marine low-speed diesel engine waste heat recovery of flue gas S-CO<sub>2</sub> recompression Brayton cycle waste heat modulation thermodynamic performance the exergy analysis |
| title | Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGA |
| title_full | Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGA |
| title_fullStr | Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGA |
| title_full_unstemmed | Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGA |
| title_short | Performance Modulation of S-CO<sub>2</sub> Brayton Cycle for Marine Low-Speed Diesel Engine Flue Gas Waste Heat Recovery Based on MOGA |
| title_sort | performance modulation of s co sub 2 sub brayton cycle for marine low speed diesel engine flue gas waste heat recovery based on moga |
| topic | marine low-speed diesel engine waste heat recovery of flue gas S-CO<sub>2</sub> recompression Brayton cycle waste heat modulation thermodynamic performance the exergy analysis |
| url | https://www.mdpi.com/1099-4300/24/11/1544 |
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