Molecular dynamics study on viscosity coefficient of working fluid in supercritical CO2 Brayton cycle: Effect of trace gas
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发布时间：2025-04-30
发布时间：2025-04-30
论文名称：Molecular dynamics study on viscosity coefficient of working fluid in supercritical CO2 Brayton cycle: Effect of trace gas
发表刊物：Journal of CO2 Utilization
摘要：Supercritical CO2 Brayton cycle has been highly recommended as a promising power cycle. As a method to improve the cycle performance, some trace gases could be introduced in the system. Due to rare viscosity coefficient data of CO2-based mixtures over the supercritical regions of CO2, the effect of trace gas on the characteristics of pressure drop has not been clarified yet. Thus, it leads to a challenge in the design and optimization of the supercritical CO2 Brayton cycle when mixing working fluid is considered. In this work, microamount Xe, the mol fraction of which ranges from 1 % to 5 %, is considered as an additive gas. The viscosity coefficient of CO2-Xe was calculated using molecular dynamics simulation. A reliable simulation strategy for the viscosity coefficient calculation was formed, which was proved available since the average relative error of the simulated viscosity coefficient of pure CO2 is around 1 % compared to the REFPROP database. Then, the influence of the addition of Xe on the viscosity coefficient and the pressure drop of the recuperator was discussed. The results demonstrate that the viscosity coefficient would change a lot when CO2 is mixed with Xe. A relative change of viscosity coefficient of 66 % can be observed. Consequently, the pressure drop of the recuperator could enlarge a lot reaching up to 12 %. This work suggests that attention must be paid to the changed viscosity during the design for a reasonable prediction when the trace gas is introduced into the system.
合写作者：Du, Z., Deng, S., Zhao, L., Nie, X., Li, S., Zhang, Y., Zhao, J., Zheng, N.
卷号：38
页面范围：177-186
是否译文：否
发表时间：2020-05-01