The thermodynamic relationship between reducing exergy destruction and improving thermal efficiency in internal combustion engines

IF 6.1 2区 工程技术 Q2 ENERGY & FUELS
Xuan Zhang , Jianan Wei , Haifeng Liu, Yuqing Cai, Hu Wang, Mingfa Yao
{"title":"The thermodynamic relationship between reducing exergy destruction and improving thermal efficiency in internal combustion engines","authors":"Xuan Zhang ,&nbsp;Jianan Wei ,&nbsp;Haifeng Liu,&nbsp;Yuqing Cai,&nbsp;Hu Wang,&nbsp;Mingfa Yao","doi":"10.1016/j.applthermaleng.2025.125875","DOIUrl":null,"url":null,"abstract":"<div><div>In this study, the effects of various overall equivalence ratios and injection strategies on the heat release rate were conducted adopting the exergy analysis method, and provides a detailed explanation of the thermodynamic relationship between reducing exergy destruction and improving thermal efficiency. The results revealed that exergy destruction during the combustion process is reduced by approximately 400 J, when the overall equivalence ratio decreased from 0.96 to 0.62, and thermal efficiency improved from about 35.0 % to 47.0 %. The equivalence ratio was further decreased to 0.38, the exergy destruction was reduced by 380 J, while the thermal efficiency was only marginally improved by less than 2 %. This indicates that the relationship between the reduction of exergy destruction and thermal efficiency is not linear. In addition, the indicated thermal efficiency can be improved by reducing the overall equivalence ratio and utilizing two-injection. The method of reducing the overall equivalence ratio changes the high-temperature stratification of the heat release, leading more mixture to enter the lean high-temperature area for reaction, while reducing the exergy destruction, which is a way to optimize the combustion “quality”. The two-injection approach modifies the equivalence ratio stratification, allowing more mixture to reach the low equivalence ratio region, where the thermomechanical exergy (It represents the work potential of the combustion process) released per unit volume of the mixed gas is high, and the exergy destruction increases, which is a method to increase the “quantity” of thermomechanical exergy. Therefore, reducing exergy destruction is a sufficient and unnecessary condition for improving thermal efficiency.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"268 ","pages":"Article 125875"},"PeriodicalIF":6.1000,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Thermal Engineering","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1359431125004661","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0

Abstract

In this study, the effects of various overall equivalence ratios and injection strategies on the heat release rate were conducted adopting the exergy analysis method, and provides a detailed explanation of the thermodynamic relationship between reducing exergy destruction and improving thermal efficiency. The results revealed that exergy destruction during the combustion process is reduced by approximately 400 J, when the overall equivalence ratio decreased from 0.96 to 0.62, and thermal efficiency improved from about 35.0 % to 47.0 %. The equivalence ratio was further decreased to 0.38, the exergy destruction was reduced by 380 J, while the thermal efficiency was only marginally improved by less than 2 %. This indicates that the relationship between the reduction of exergy destruction and thermal efficiency is not linear. In addition, the indicated thermal efficiency can be improved by reducing the overall equivalence ratio and utilizing two-injection. The method of reducing the overall equivalence ratio changes the high-temperature stratification of the heat release, leading more mixture to enter the lean high-temperature area for reaction, while reducing the exergy destruction, which is a way to optimize the combustion “quality”. The two-injection approach modifies the equivalence ratio stratification, allowing more mixture to reach the low equivalence ratio region, where the thermomechanical exergy (It represents the work potential of the combustion process) released per unit volume of the mixed gas is high, and the exergy destruction increases, which is a method to increase the “quantity” of thermomechanical exergy. Therefore, reducing exergy destruction is a sufficient and unnecessary condition for improving thermal efficiency.
求助全文
约1分钟内获得全文 求助全文
来源期刊
Applied Thermal Engineering
Applied Thermal Engineering 工程技术-工程:机械
CiteScore
11.30
自引率
15.60%
发文量
1474
审稿时长
57 days
期刊介绍: Applied Thermal Engineering disseminates novel research related to the design, development and demonstration of components, devices, equipment, technologies and systems involving thermal processes for the production, storage, utilization and conservation of energy, with a focus on engineering application. The journal publishes high-quality and high-impact Original Research Articles, Review Articles, Short Communications and Letters to the Editor on cutting-edge innovations in research, and recent advances or issues of interest to the thermal engineering community.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信