Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers
Autor(a) principal: | |
---|---|
Data de Publicação: | 2007 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1590/S0104-66322007000400005 http://hdl.handle.net/11449/24969 |
Resumo: | Due to the wide range of design possibilities, simple manufactured, low maintenance and low cost, cross-flow heat exchangers are extensively used in the petroleum, petrochemical, air conditioning, food storage, and others industries. In this paper a mathematical model for cross-flow heat exchangers with complex flow arrangements for determining epsilon -NTU relations is presented. The model is based on the tube element approach, according to which the heat exchanger outlet temperatures are obtained by discretizing the coil along the tube fluid path. In each cross section of the element, tube-side fluid temperature is assumed to be constant because the heat capacity rate ratio C*=Cmin/Cmax tends toward zero in the element. Thus temperature is controlled by effectiveness of a local element corresponding to an evaporator or a condenser-type element. The model is validated through comparison with theoretical algebraic relations for single-pass cross-flow arrangements with one or more rows. Very small relative errors are obtained showing the accuracy of the present model. epsilon -NTU curves for several complex circuit arrangements are presented. The model developed represents a useful research tool for theoretical and experimental studies on heat exchangers performance. |
id |
UNSP_4960fbc75d3c557eff1ed493e4894b1b |
---|---|
oai_identifier_str |
oai:repositorio.unesp.br:11449/24969 |
network_acronym_str |
UNSP |
network_name_str |
Repositório Institucional da UNESP |
repository_id_str |
2946 |
spelling |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangersEffectivenessNTUHeat exchangersMathematical modelDue to the wide range of design possibilities, simple manufactured, low maintenance and low cost, cross-flow heat exchangers are extensively used in the petroleum, petrochemical, air conditioning, food storage, and others industries. In this paper a mathematical model for cross-flow heat exchangers with complex flow arrangements for determining epsilon -NTU relations is presented. The model is based on the tube element approach, according to which the heat exchanger outlet temperatures are obtained by discretizing the coil along the tube fluid path. In each cross section of the element, tube-side fluid temperature is assumed to be constant because the heat capacity rate ratio C*=Cmin/Cmax tends toward zero in the element. Thus temperature is controlled by effectiveness of a local element corresponding to an evaporator or a condenser-type element. The model is validated through comparison with theoretical algebraic relations for single-pass cross-flow arrangements with one or more rows. Very small relative errors are obtained showing the accuracy of the present model. epsilon -NTU curves for several complex circuit arrangements are presented. The model developed represents a useful research tool for theoretical and experimental studies on heat exchangers performance.UNESP IGCE Matemática Aplicada e ComputaçãoUSP Escola de Engenharia de São Carlos Departamento de Engenharia MecânicaUNESP IGCE Matemática Aplicada e ComputaçãoBrazilian Society of Chemical EngineeringUniversidade Estadual Paulista (Unesp)Universidade de São Paulo (USP)Navarro, H. A. [UNESP]Cabezas-Gómez, L. C.2013-09-30T18:50:47Z2014-05-20T14:16:32Z2013-09-30T18:50:47Z2014-05-20T14:16:32Z2007-12-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article509-521application/pdfhttp://dx.doi.org/10.1590/S0104-66322007000400005Brazilian Journal of Chemical Engineering. Brazilian Society of Chemical Engineering, v. 24, n. 4, p. 509-521, 2007.0104-6632http://hdl.handle.net/11449/2496910.1590/S0104-66322007000400005S0104-66322007000400005S0104-66322007000400005.pdfSciELOreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengBrazilian Journal of Chemical Engineering0.9250,395info:eu-repo/semantics/openAccess2023-11-09T06:11:29Zoai:repositorio.unesp.br:11449/24969Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462024-08-05T17:14:36.826323Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers |
title |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers |
spellingShingle |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers Navarro, H. A. [UNESP] Effectiveness NTU Heat exchangers Mathematical model |
title_short |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers |
title_full |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers |
title_fullStr |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers |
title_full_unstemmed |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers |
title_sort |
Effectiveness-ntu computation with a mathematical model for cross-flow heat exchangers |
author |
Navarro, H. A. [UNESP] |
author_facet |
Navarro, H. A. [UNESP] Cabezas-Gómez, L. C. |
author_role |
author |
author2 |
Cabezas-Gómez, L. C. |
author2_role |
author |
dc.contributor.none.fl_str_mv |
Universidade Estadual Paulista (Unesp) Universidade de São Paulo (USP) |
dc.contributor.author.fl_str_mv |
Navarro, H. A. [UNESP] Cabezas-Gómez, L. C. |
dc.subject.por.fl_str_mv |
Effectiveness NTU Heat exchangers Mathematical model |
topic |
Effectiveness NTU Heat exchangers Mathematical model |
description |
Due to the wide range of design possibilities, simple manufactured, low maintenance and low cost, cross-flow heat exchangers are extensively used in the petroleum, petrochemical, air conditioning, food storage, and others industries. In this paper a mathematical model for cross-flow heat exchangers with complex flow arrangements for determining epsilon -NTU relations is presented. The model is based on the tube element approach, according to which the heat exchanger outlet temperatures are obtained by discretizing the coil along the tube fluid path. In each cross section of the element, tube-side fluid temperature is assumed to be constant because the heat capacity rate ratio C*=Cmin/Cmax tends toward zero in the element. Thus temperature is controlled by effectiveness of a local element corresponding to an evaporator or a condenser-type element. The model is validated through comparison with theoretical algebraic relations for single-pass cross-flow arrangements with one or more rows. Very small relative errors are obtained showing the accuracy of the present model. epsilon -NTU curves for several complex circuit arrangements are presented. The model developed represents a useful research tool for theoretical and experimental studies on heat exchangers performance. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007-12-01 2013-09-30T18:50:47Z 2013-09-30T18:50:47Z 2014-05-20T14:16:32Z 2014-05-20T14:16:32Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1590/S0104-66322007000400005 Brazilian Journal of Chemical Engineering. Brazilian Society of Chemical Engineering, v. 24, n. 4, p. 509-521, 2007. 0104-6632 http://hdl.handle.net/11449/24969 10.1590/S0104-66322007000400005 S0104-66322007000400005 S0104-66322007000400005.pdf |
url |
http://dx.doi.org/10.1590/S0104-66322007000400005 http://hdl.handle.net/11449/24969 |
identifier_str_mv |
Brazilian Journal of Chemical Engineering. Brazilian Society of Chemical Engineering, v. 24, n. 4, p. 509-521, 2007. 0104-6632 10.1590/S0104-66322007000400005 S0104-66322007000400005 S0104-66322007000400005.pdf |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Brazilian Journal of Chemical Engineering 0.925 0,395 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
509-521 application/pdf |
dc.publisher.none.fl_str_mv |
Brazilian Society of Chemical Engineering |
publisher.none.fl_str_mv |
Brazilian Society of Chemical Engineering |
dc.source.none.fl_str_mv |
SciELO 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 |
|
_version_ |
1808128777779150848 |