{"title":"Numerical modeling and transient analysis of printed circuit heat exchangers in the supercritical CO2/propane mixture Brayton cycle","authors":"Yunlong Zhou, Dandan Yin, Xintian Guo, Cunlin Dong","doi":"10.1016/j.ijheatmasstransfer.2024.125896","DOIUrl":null,"url":null,"abstract":"<div><p>CO<sub>2</sub>/propane mixtures benefit the safe operation of the supercritical Brayton cycle while improving economic efficiency and mitigating environmental impact. Due to the intermittency of energy resources, understanding the dynamic characteristics of the supercritical mixture Brayton cycle is essential. The transition time of the cycle depends on the total time of the unsteady-state heat transfer. As a typical heat exchanger, the transient analysis of the printed circuit heat exchanger (PCHE) is necessary and significant. In this paper, the dynamic response of the straight PCHE in the supercritical CO<sub>2</sub>/propane mixture Brayton cycle is thoroughly studied. First, the dynamic behavior of the mixture-mixture PCHE is analyzed when the inlet temperature or mass flow rate abruptly changes. Furthermore, the equilibrium times of the mixture-mixture PCHE under different disturbances are compared. CO<sub>2</sub>/propane mixtures are more favorable for the stability of the parameters (outlet temperature and pressure drop). The mixture-mixture PCHE exhibits better flow and heat transfer properties than the CO<sub>2<img></sub>CO<sub>2</sub> PCHE. Compared to CO<sub>2</sub>, CO<sub>2</sub>/propane mixtures could reduce the equilibrium time by more than 32 % when the molar fraction of propane is equal to 0.5. However, the outlet temperature of the mixtures in the hot channel is higher than that of CO<sub>2</sub>, because the energy is not fully utilized.</p></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":null,"pages":null},"PeriodicalIF":5.0000,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Heat and Mass Transfer","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0017931024007270","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
CO2/propane mixtures benefit the safe operation of the supercritical Brayton cycle while improving economic efficiency and mitigating environmental impact. Due to the intermittency of energy resources, understanding the dynamic characteristics of the supercritical mixture Brayton cycle is essential. The transition time of the cycle depends on the total time of the unsteady-state heat transfer. As a typical heat exchanger, the transient analysis of the printed circuit heat exchanger (PCHE) is necessary and significant. In this paper, the dynamic response of the straight PCHE in the supercritical CO2/propane mixture Brayton cycle is thoroughly studied. First, the dynamic behavior of the mixture-mixture PCHE is analyzed when the inlet temperature or mass flow rate abruptly changes. Furthermore, the equilibrium times of the mixture-mixture PCHE under different disturbances are compared. CO2/propane mixtures are more favorable for the stability of the parameters (outlet temperature and pressure drop). The mixture-mixture PCHE exhibits better flow and heat transfer properties than the CO2CO2 PCHE. Compared to CO2, CO2/propane mixtures could reduce the equilibrium time by more than 32 % when the molar fraction of propane is equal to 0.5. However, the outlet temperature of the mixtures in the hot channel is higher than that of CO2, because the energy is not fully utilized.
期刊介绍:
International Journal of Heat and Mass Transfer is the vehicle for the exchange of basic ideas in heat and mass transfer between research workers and engineers throughout the world. It focuses on both analytical and experimental research, with an emphasis on contributions which increase the basic understanding of transfer processes and their application to engineering problems.
Topics include:
-New methods of measuring and/or correlating transport-property data
-Energy engineering
-Environmental applications of heat and/or mass transfer