{"title":"Strategies to improve the thermal performance of solar collectors","authors":"Bader Alshuraiaan","doi":"10.1515/jnet-2023-0040","DOIUrl":null,"url":null,"abstract":"The paper evaluates a passive method for heat transfer improvement in heat exchangers, which implies the use of nanofluids. All calculations were carried out with a constant volumetric flow rate. The study examines three fluids with 0–4 % volume concentrations of CuO, MgO, and Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> particles. The results indicate an increase in the heat transfer coefficient with increasing temperature. An Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> nanofluid (4 % concentration) contributed to the best thermal performance. The incorporation of a 4 % content of MgO yielded an augmentation in heat transfer ranging from 15 % to 22 %, whereas an analogous concentration of CuO led to a more substantial enhancement of 25 %. Notably, the introduction of nanoparticles of Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> produces a remarkable augmentation in heat transfer performance, with potential improvements of up to 36 %. The Nusselt number increases with increasing particle volume fraction and Reynolds number, according to results obtained for several nanoparticles (Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, CuO, SiO<jats:sub>2</jats:sub>, and ZnO) with volume percentages in the range of 1–4 % and nanoparticle diameters of 25–70 nm. For all nanofluids, the time-averaged Nusselt number rises with a solid phase volume fraction increase of less than 5 %.","PeriodicalId":16428,"journal":{"name":"Journal of Non-Equilibrium Thermodynamics","volume":null,"pages":null},"PeriodicalIF":4.3000,"publicationDate":"2024-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Non-Equilibrium Thermodynamics","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1515/jnet-2023-0040","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MECHANICS","Score":null,"Total":0}
引用次数: 0
Abstract
The paper evaluates a passive method for heat transfer improvement in heat exchangers, which implies the use of nanofluids. All calculations were carried out with a constant volumetric flow rate. The study examines three fluids with 0–4 % volume concentrations of CuO, MgO, and Al2O3 particles. The results indicate an increase in the heat transfer coefficient with increasing temperature. An Al2O3 nanofluid (4 % concentration) contributed to the best thermal performance. The incorporation of a 4 % content of MgO yielded an augmentation in heat transfer ranging from 15 % to 22 %, whereas an analogous concentration of CuO led to a more substantial enhancement of 25 %. Notably, the introduction of nanoparticles of Al2O3 produces a remarkable augmentation in heat transfer performance, with potential improvements of up to 36 %. The Nusselt number increases with increasing particle volume fraction and Reynolds number, according to results obtained for several nanoparticles (Al2O3, CuO, SiO2, and ZnO) with volume percentages in the range of 1–4 % and nanoparticle diameters of 25–70 nm. For all nanofluids, the time-averaged Nusselt number rises with a solid phase volume fraction increase of less than 5 %.
期刊介绍:
The Journal of Non-Equilibrium Thermodynamics serves as an international publication organ for new ideas, insights and results on non-equilibrium phenomena in science, engineering and related natural systems. The central aim of the journal is to provide a bridge between science and engineering and to promote scientific exchange on a) newly observed non-equilibrium phenomena, b) analytic or numeric modeling for their interpretation, c) vanguard methods to describe non-equilibrium phenomena.
Contributions should – among others – present novel approaches to analyzing, modeling and optimizing processes of engineering relevance such as transport processes of mass, momentum and energy, separation of fluid phases, reproduction of living cells, or energy conversion. The journal is particularly interested in contributions which add to the basic understanding of non-equilibrium phenomena in science and engineering, with systems of interest ranging from the macro- to the nano-level.
The Journal of Non-Equilibrium Thermodynamics has recently expanded its scope to place new emphasis on theoretical and experimental investigations of non-equilibrium phenomena in thermophysical, chemical, biochemical and abstract model systems of engineering relevance. We are therefore pleased to invite submissions which present newly observed non-equilibrium phenomena, analytic or fuzzy models for their interpretation, or new methods for their description.