Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids

Detalhes bibliográficos
Autor(a) principal: Kiyomura, Igor Seicho [UNESP]
Data de Publicação: 2020
Outros Autores: Nunes, Jéssica Martha [UNESP], Rodrigues de Souza, Reinaldo [UNESP], Cardoso, Elaine Maria [UNESP]
Tipo de documento: Artigo de conferência
Idioma: eng
Título da fonte: Repositório Institucional da UNESP
Texto Completo: http://dx.doi.org/10.1615/TFEC2020.boi.032136
http://hdl.handle.net/11449/205210
Resumo: One promising way to enhance the heat transfer coefficient (HTC) and the critical heat flux (CHF) is modifying the heating surface morphology by using machining techniques, coating, and chemical processes. Microstructured surfaces, i.e., surfaces with the presence of micro-pillars on the surface, provide small perturbations in the liquid, affecting the vapor bubbles dynamic. These structures increase the heating surface area and change the fluid flow. Micro-fins can have different shapes and sizes and can be arranged in different patterns to improve heat transfer. This study aims to evaluate experimentally the thermal performance of different micro-fin surfaces by using HFE-7100 as working fluid. The square-micro pillar arrays were etched on a plain copper surface through the micro-milling process. Squares micro-fins of different length scales (i.e., height and side length) were uniformly spaced on the plain copper surface. The inter-fin space had the same value, 250 μm, for all surfaces in order to control the effective roughness, Reff, defined as the ratio of the area in contact with the liquid to the projected area. Micro-fin surfaces intensify the HTC as compared to the plain surface and the number of fins is the main factor for the HTC enhancement; if the number of micro-fins is constant, the larger the effective roughness the higher the heat transfer performance. Additionally, the capillary-wicking ability increases and it also improves the HTC and the dryout heat flux due to the prevention of hotspots in the micro-fin surface. Thus, the surface thermal behavior is a function of the surface morphology and its surface capillary wicking.
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spelling Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluidsEffective roughnessHeat transfer coefficientHFE-7100Micro-pillarsPool boilingOne promising way to enhance the heat transfer coefficient (HTC) and the critical heat flux (CHF) is modifying the heating surface morphology by using machining techniques, coating, and chemical processes. Microstructured surfaces, i.e., surfaces with the presence of micro-pillars on the surface, provide small perturbations in the liquid, affecting the vapor bubbles dynamic. These structures increase the heating surface area and change the fluid flow. Micro-fins can have different shapes and sizes and can be arranged in different patterns to improve heat transfer. This study aims to evaluate experimentally the thermal performance of different micro-fin surfaces by using HFE-7100 as working fluid. The square-micro pillar arrays were etched on a plain copper surface through the micro-milling process. Squares micro-fins of different length scales (i.e., height and side length) were uniformly spaced on the plain copper surface. The inter-fin space had the same value, 250 μm, for all surfaces in order to control the effective roughness, Reff, defined as the ratio of the area in contact with the liquid to the projected area. Micro-fin surfaces intensify the HTC as compared to the plain surface and the number of fins is the main factor for the HTC enhancement; if the number of micro-fins is constant, the larger the effective roughness the higher the heat transfer performance. Additionally, the capillary-wicking ability increases and it also improves the HTC and the dryout heat flux due to the prevention of hotspots in the micro-fin surface. Thus, the surface thermal behavior is a function of the surface morphology and its surface capillary wicking.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNESP – São Paulo State University School of Engineering Post-Graduation Program in Mechanical Engineering, Av. Brasil, 56UNESP – São Paulo State University Campus of São João da Boa VistaUNESP – São Paulo State University School of Engineering Post-Graduation Program in Mechanical Engineering, Av. Brasil, 56UNESP – São Paulo State University Campus of São João da Boa VistaCNPq: 458702/2014-5Universidade Estadual Paulista (Unesp)Kiyomura, Igor Seicho [UNESP]Nunes, Jéssica Martha [UNESP]Rodrigues de Souza, Reinaldo [UNESP]Cardoso, Elaine Maria [UNESP]2021-06-25T10:11:39Z2021-06-25T10:11:39Z2020-01-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObject15-23http://dx.doi.org/10.1615/TFEC2020.boi.032136Proceedings of the Thermal and Fluids Engineering Summer Conference, v. 2020-April, p. 15-23.2379-1748http://hdl.handle.net/11449/20521010.1615/TFEC2020.boi.0321362-s2.0-85091382305Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengProceedings of the Thermal and Fluids Engineering Summer Conferenceinfo:eu-repo/semantics/openAccess2021-10-23T12:10:31Zoai:repositorio.unesp.br:11449/205210Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T22:09:57.078421Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false
dc.title.none.fl_str_mv Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
title Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
spellingShingle Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
Kiyomura, Igor Seicho [UNESP]
Effective roughness
Heat transfer coefficient
HFE-7100
Micro-pillars
Pool boiling
title_short Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
title_full Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
title_fullStr Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
title_full_unstemmed Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
title_sort Pool boiling heat transfer enhancement using micro-fin surfaces and dielectric fluids
author Kiyomura, Igor Seicho [UNESP]
author_facet Kiyomura, Igor Seicho [UNESP]
Nunes, Jéssica Martha [UNESP]
Rodrigues de Souza, Reinaldo [UNESP]
Cardoso, Elaine Maria [UNESP]
author_role author
author2 Nunes, Jéssica Martha [UNESP]
Rodrigues de Souza, Reinaldo [UNESP]
Cardoso, Elaine Maria [UNESP]
author2_role author
author
author
dc.contributor.none.fl_str_mv Universidade Estadual Paulista (Unesp)
dc.contributor.author.fl_str_mv Kiyomura, Igor Seicho [UNESP]
Nunes, Jéssica Martha [UNESP]
Rodrigues de Souza, Reinaldo [UNESP]
Cardoso, Elaine Maria [UNESP]
dc.subject.por.fl_str_mv Effective roughness
Heat transfer coefficient
HFE-7100
Micro-pillars
Pool boiling
topic Effective roughness
Heat transfer coefficient
HFE-7100
Micro-pillars
Pool boiling
description One promising way to enhance the heat transfer coefficient (HTC) and the critical heat flux (CHF) is modifying the heating surface morphology by using machining techniques, coating, and chemical processes. Microstructured surfaces, i.e., surfaces with the presence of micro-pillars on the surface, provide small perturbations in the liquid, affecting the vapor bubbles dynamic. These structures increase the heating surface area and change the fluid flow. Micro-fins can have different shapes and sizes and can be arranged in different patterns to improve heat transfer. This study aims to evaluate experimentally the thermal performance of different micro-fin surfaces by using HFE-7100 as working fluid. The square-micro pillar arrays were etched on a plain copper surface through the micro-milling process. Squares micro-fins of different length scales (i.e., height and side length) were uniformly spaced on the plain copper surface. The inter-fin space had the same value, 250 μm, for all surfaces in order to control the effective roughness, Reff, defined as the ratio of the area in contact with the liquid to the projected area. Micro-fin surfaces intensify the HTC as compared to the plain surface and the number of fins is the main factor for the HTC enhancement; if the number of micro-fins is constant, the larger the effective roughness the higher the heat transfer performance. Additionally, the capillary-wicking ability increases and it also improves the HTC and the dryout heat flux due to the prevention of hotspots in the micro-fin surface. Thus, the surface thermal behavior is a function of the surface morphology and its surface capillary wicking.
publishDate 2020
dc.date.none.fl_str_mv 2020-01-01
2021-06-25T10:11:39Z
2021-06-25T10:11:39Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/conferenceObject
format conferenceObject
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://dx.doi.org/10.1615/TFEC2020.boi.032136
Proceedings of the Thermal and Fluids Engineering Summer Conference, v. 2020-April, p. 15-23.
2379-1748
http://hdl.handle.net/11449/205210
10.1615/TFEC2020.boi.032136
2-s2.0-85091382305
url http://dx.doi.org/10.1615/TFEC2020.boi.032136
http://hdl.handle.net/11449/205210
identifier_str_mv Proceedings of the Thermal and Fluids Engineering Summer Conference, v. 2020-April, p. 15-23.
2379-1748
10.1615/TFEC2020.boi.032136
2-s2.0-85091382305
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv Proceedings of the Thermal and Fluids Engineering Summer Conference
dc.rights.driver.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 15-23
dc.source.none.fl_str_mv Scopus
reponame:Repositório Institucional da UNESP
instname:Universidade Estadual Paulista (UNESP)
instacron:UNESP
instname_str Universidade Estadual Paulista (UNESP)
instacron_str UNESP
institution UNESP
reponame_str Repositório Institucional da UNESP
collection Repositório Institucional da UNESP
repository.name.fl_str_mv Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)
repository.mail.fl_str_mv
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