{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/20421"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/20421","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Performance and optimization of microchannel condensers","abstract":"This study is the first to document the condensation heat transfer performance of small diameter, microchannel tubes in crossflow heat exchange, and this study provides the first systematic evaluation of the effect of port shape on microchannel tube performance. Furthermore, this study is the first to suggest methods for improving microchannel heat exchanger designs.","abstract_html":"This study is the first to document the condensation heat transfer performance of small diameter, microchannel tubes in crossflow heat exchange, and this study provides the first systematic evaluation of the effect of port shape on microchannel tube performance. Furthermore, this study is the first to suggest methods for improving microchannel heat exchanger designs.","abstract_has_math":false,"creators":["Heun, Matthew Kuperus"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Dunn, William E."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:38:43Z","date_published":"2011-05-07T12:38:43Z","updated_at":"2026-07-22T22:25:15Z","subjects":["Engineering, Mechanical"],"languages":["eng"],"rights":["Copyright 1995 Heun, Matthew Kuperus"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9624362","(UMI)AAI9624362"],"render_values":[{"text":"AAI9624362","href":null,"code":true},{"text":"(UMI)AAI9624362","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/20421","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dunn, William E."]},{"key":"dc:creator","label":"Author","values":["Heun, Matthew Kuperus"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:38:43Z","10000-01-01","1995"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Mechanical"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1995 Heun, Matthew Kuperus"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9624362","(UMI)AAI9624362","http://hdl.handle.net/2142/20421"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["This study is the first to document the condensation heat transfer performance of small diameter, microchannel tubes in crossflow heat exchange, and this study provides the first systematic evaluation of the effect of port shape on microchannel tube performance. Furthermore, this study is the first to suggest methods for improving microchannel heat exchanger designs.","We collected experimental data for flat, multiport tubes with hydraulic diameters in the range of 0.6 mm $\\leq\\rm D\\sb{h}\\leq$ 1.5 mm. The port shapes considered were circles, squares, triangles, enhanced squares, and small squares. We found that established relationships describe single-phase circular-tube heat transfer and pressure drop behavior in microchannel tubes. Circular-tube correlations are appropriate length scales. The wavy flow correlation of Dobson (1994) was found to predict accurately condensing heat transfer in flows predicted to wavy. A slightly modified form of the Dobson (1994) annual flow correlation was found to predict accurately condensing heat transfer in flows predicted to be annular.","An analytical study of methods to improve microchannel condenser design was performed. We found that volume minimization is a comprehensive and reasonable objective for the suboptimization analysis. As condenser volume is reduced, system charge, condenser mass, and material costs all decrease.","Refrigerant-side circuiting flexibility is the key that unlocks the potential of the microchannel technology. With unconstrained refrigerant circuiting, smaller port diameters always lead to reduced condenser volume. However, the pressure-drop effect drives optimal condenser designs toward many tubes of short length, and the crossflow-heat-exchanger effect drives optimal condenser designs toward many tubes of short length and few ports.","We found that port shape significantly impacts condenser designs. To achieve reduced internal volume, the order of preference for port shapes is circle, square, and triangle. To achieve minimized external volume, the order of preference for port shapes is triangle, square, and circle.","Made available in DSpace on 2011-05-07T12:38:43Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9624362.pdf: 9687386 bytes, checksum: ecd1293fd0d9961ebb4271ccfa2e7430 (MD5) Previous issue date: 1995","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:43:47Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:19:12-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Performance and optimization of microchannel condensers"]}]}],"canonical_facts":{"dc:contributor":["Dunn, William E."],"dc:creator":["Heun, Matthew Kuperus"],"dc:date":["2011-05-07T12:38:43Z","10000-01-01","1995"],"dc:description":["This study is the first to document the condensation heat transfer performance of small diameter, microchannel tubes in crossflow heat exchange, and this study provides the first systematic evaluation of the effect of port shape on microchannel tube performance. Furthermore, this study is the first to suggest methods for improving microchannel heat exchanger designs.","We collected experimental data for flat, multiport tubes with hydraulic diameters in the range of 0.6 mm $\\leq\\rm D\\sb{h}\\leq$ 1.5 mm. The port shapes considered were circles, squares, triangles, enhanced squares, and small squares. We found that established relationships describe single-phase circular-tube heat transfer and pressure drop behavior in microchannel tubes. Circular-tube correlations are appropriate length scales. The wavy flow correlation of Dobson (1994) was found to predict accurately condensing heat transfer in flows predicted to wavy. A slightly modified form of the Dobson (1994) annual flow correlation was found to predict accurately condensing heat transfer in flows predicted to be annular.","An analytical study of methods to improve microchannel condenser design was performed. We found that volume minimization is a comprehensive and reasonable objective for the suboptimization analysis. As condenser volume is reduced, system charge, condenser mass, and material costs all decrease.","Refrigerant-side circuiting flexibility is the key that unlocks the potential of the microchannel technology. With unconstrained refrigerant circuiting, smaller port diameters always lead to reduced condenser volume. However, the pressure-drop effect drives optimal condenser designs toward many tubes of short length, and the crossflow-heat-exchanger effect drives optimal condenser designs toward many tubes of short length and few ports.","We found that port shape significantly impacts condenser designs. To achieve reduced internal volume, the order of preference for port shapes is circle, square, and triangle. To achieve minimized external volume, the order of preference for port shapes is triangle, square, and circle.","Made available in DSpace on 2011-05-07T12:38:43Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9624362.pdf: 9687386 bytes, checksum: ecd1293fd0d9961ebb4271ccfa2e7430 (MD5) Previous issue date: 1995","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:43:47Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:19:12-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9624362","(UMI)AAI9624362","http://hdl.handle.net/2142/20421"],"dc:language":["eng"],"dc:rights":["Copyright 1995 Heun, Matthew Kuperus"],"dc:subject":["Engineering, Mechanical"],"dc:title":["Performance and optimization of microchannel condensers"],"dc:type":["text"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:15Z"}