Thermal analysis and performance optimization of supercritical carbon dioxide Brayton cycle based on ship waste heat

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow Pub Date : 2025-08-25 DOI:10.1016/j.ijheatfluidflow.2025.110020

Junshuai Lv , Yuwei Sun , Chengqing Yuan , Tianyang Qin , Wenkang Ding , Ruipeng Sun

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引用次数: 0

Abstract

The global shipping industry is increasingly focused on energy conservation and emission reduction, driving the development of green technologies. Utilizing supercritical carbon dioxide (SCO₂) power generation to recover waste heat from marine engines has proven to be an effective approach to improve energy efficiency and reduce carbon emissions. In this study, waste heat from the main engine of a 9000 TEU container ship serves as the heat source for an SCO₂ power cycle incorporating a CO₂-propane (C₃H₈) binary mixture. A convolutional neural network (CNN) model was developed to predict system performance, using split ratio, mixing ratio, main compressor (MC) inlet temperature, and turbine inlet temperature as inputs. The results show that the determination coefficients R² of the model were 0.941 and 0.931 for the training set, while they were 0.922 and 0.912 for the test set. Multi-objective optimization based on response surface methodology (RSM) identified the optimal operating conditions as a split ratio of 0.39, mixing ratio of 14.2 %, MC inlet temperature of 34.17 °C, and turbine inlet temperature of 472.85 °C. Under these conditions, the SCO₂ system achieves a thermal efficiency of 25.81 % and an exergy efficiency of 41.55 %. These results demonstrate the significant potential of CO₂-C₃H₈ mixtures to enhance waste heat recovery in marine applications, contributing to cleaner and more efficient shipping energy systems.

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船舶余热超临界二氧化碳布雷顿循环热分析及性能优化

全球航运业日益重视节能减排，推动绿色技术发展。利用超临界二氧化碳（SCO2）发电来回收船用发动机的废热已被证明是提高能源效率和减少碳排放的有效方法。在本研究中，一艘9000 TEU集装箱船主机的废热作为含二氧化碳-丙烷（C3H8）二元混合物的SCO2动力循环的热源。采用分割比、混合比、主压气机（MC）进口温度和涡轮进口温度作为输入，建立了卷积神经网络（CNN）模型来预测系统性能。结果表明，模型的决定系数R2对于训练集分别为0.941和0.931，对于测试集分别为0.922和0.912。基于响应面法（RSM）的多目标优化确定了最优工况为分流比0.39、混合比14.2%、MC进口温度34.17℃、涡轮进口温度472.85℃。在此条件下，SCO2系统的热效率为25.81%，火用效率为41.55%。这些结果表明，二氧化碳- c3h8混合物在加强海洋应用中的废热回收方面具有巨大潜力，有助于建立更清洁、更高效的航运能源系统。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

International Journal of Heat and Fluid Flow 工程技术-工程：机械

CiteScore

5.00

自引率

7.70%

发文量

131

审稿时长

33 days

期刊介绍： The International Journal of Heat and Fluid Flow welcomes high-quality original contributions on experimental, computational, and physical aspects of convective heat transfer and fluid dynamics relevant to engineering or the environment, including multiphase and microscale flows. Papers reporting the application of these disciplines to design and development, with emphasis on new technological fields, are also welcomed. Some of these new fields include microscale electronic and mechanical systems; medical and biological systems; and thermal and flow control in both the internal and external environment.