{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/102850"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/102850","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Improvements on performance of a heat pump water heater system","abstract":"Heat Pump Water Heater (HPWH) is classified as one renewable energy efficient technology, which could be explained by their environmentally friendly nature with low energy consumption. The Coefficient of Performance (COP) of the HPWH can be influenced by multiple factors: ambient temperature, relative humidity, hot water usage profile, the size and shape of heat exchangers (evaporator and condenser), type and shape of compressor, refrigerant, filling capacity of refrigerant, etc. Therefore, in this study, the performance of HPWH is critically examine to ascertain its optimal operation condition. Three main factors are considered here: use pattern of water in tank, drop-in refrigerant R1234yf and condenser configuration. This study examines two different models, HPWH-66 and HPWH-50. Simulation is employed and suggestions are made towards a better performance. The performance of HPWH system is found to strongly depend on the stratification of water in the storage tank, then 3D CFD simulation has been used to explore the entrance effects on the thermal tank. In the drop-in experiments, it is shown that R1234yf can be a desirable alternative for the baseline R134a without any special changes to the heat pump facility. By closing the valves at the inlet and outlet of one condenser circuit, a one-circuit condenser system could be achieved. For both refrigerant system, one-circuit condenser only brings the COP down within 5.5%. Finally, a linked EES-Fluent model has been developed to simulate the transient heating-up performance of the HPWH system with the validation by experimental data.","abstract_html":"Heat Pump Water Heater (HPWH) is classified as one renewable energy efficient technology, which could be explained by their environmentally friendly nature with low energy consumption. The Coefficient of Performance (COP) of the HPWH can be influenced by multiple factors: ambient temperature, relative humidity, hot water usage profile, the size and shape of heat exchangers (evaporator and condenser), type and shape of compressor, refrigerant, filling capacity of refrigerant, etc. Therefore, in this study, the performance of HPWH is critically examine to ascertain its optimal operation condition. Three main factors are considered here: use pattern of water in tank, drop-in refrigerant R1234yf and condenser configuration. This study examines two different models, HPWH-66 and HPWH-50. Simulation is employed and suggestions are made towards a better performance. The performance of HPWH system is found to strongly depend on the stratification of water in the storage tank, then 3D CFD simulation has been used to explore the entrance effects on the thermal tank. In the drop-in experiments, it is shown that R1234yf can be a desirable alternative for the baseline R134a without any special changes to the heat pump facility. By closing the valves at the inlet and outlet of one condenser circuit, a one-circuit condenser system could be achieved. For both refrigerant system, one-circuit condenser only brings the COP down within 5.5%. Finally, a linked EES-Fluent model has been developed to simulate the transient heating-up performance of the HPWH system with the validation by experimental data.","abstract_has_math":false,"creators":["Shi, Ce"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Hrnjak, Predrag"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019-02-07T20:44:27Z","date_published":"2019-02-07T20:44:27Z","updated_at":"2026-07-22T22:24:42Z","subjects":["Heat Pump Water Heater","COP"],"languages":["en"],"rights":["Copyright 2018 Ce Shi"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/102850","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Hrnjak, Predrag"]},{"key":"dc:creator","label":"Author","values":["Shi, Ce"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2019-02-07T20:44:27Z","2021-02-08T10:15:29Z","2018-12-12","2018-12"]},{"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":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Heat Pump Water Heater","COP"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2018 Ce Shi"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/102850"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Heat Pump Water Heater (HPWH) is classified as one renewable energy efficient technology, which could be explained by their environmentally friendly nature with low energy consumption. The Coefficient of Performance (COP) of the HPWH can be influenced by multiple factors: ambient temperature, relative humidity, hot water usage profile, the size and shape of heat exchangers (evaporator and condenser), type and shape of compressor, refrigerant, filling capacity of refrigerant, etc. Therefore, in this study, the performance of HPWH is critically examine to ascertain its optimal operation condition. Three main factors are considered here: use pattern of water in tank, drop-in refrigerant R1234yf and condenser configuration. This study examines two different models, HPWH-66 and HPWH-50. Simulation is employed and suggestions are made towards a better performance. The performance of HPWH system is found to strongly depend on the stratification of water in the storage tank, then 3D CFD simulation has been used to explore the entrance effects on the thermal tank. In the drop-in experiments, it is shown that R1234yf can be a desirable alternative for the baseline R134a without any special changes to the heat pump facility. By closing the valves at the inlet and outlet of one condenser circuit, a one-circuit condenser system could be achieved. For both refrigerant system, one-circuit condenser only brings the COP down within 5.5%. Finally, a linked EES-Fluent model has been developed to simulate the transient heating-up performance of the HPWH system with the validation by experimental data.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-12-01","The student, Ce Shi, accepted the attached license on 2018-12-10 at 17:20.","The student, Ce Shi, submitted this Thesis for approval on 2018-12-11 at 10:34.","This Thesis was approved for publication on 2018-12-12 at 16:19.","DSpace SAF Submission Ingestion Package generated from Vireo submission #13262 on 2019-02-07 at 14:23:07","Made available in DSpace on 2019-02-07T20:44:27Z (GMT). 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The Coefficient of Performance (COP) of the HPWH can be influenced by multiple factors: ambient temperature, relative humidity, hot water usage profile, the size and shape of heat exchangers (evaporator and condenser), type and shape of compressor, refrigerant, filling capacity of refrigerant, etc. Therefore, in this study, the performance of HPWH is critically examine to ascertain its optimal operation condition. Three main factors are considered here: use pattern of water in tank, drop-in refrigerant R1234yf and condenser configuration. This study examines two different models, HPWH-66 and HPWH-50. Simulation is employed and suggestions are made towards a better performance. The performance of HPWH system is found to strongly depend on the stratification of water in the storage tank, then 3D CFD simulation has been used to explore the entrance effects on the thermal tank. In the drop-in experiments, it is shown that R1234yf can be a desirable alternative for the baseline R134a without any special changes to the heat pump facility. By closing the valves at the inlet and outlet of one condenser circuit, a one-circuit condenser system could be achieved. For both refrigerant system, one-circuit condenser only brings the COP down within 5.5%. Finally, a linked EES-Fluent model has been developed to simulate the transient heating-up performance of the HPWH system with the validation by experimental data.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-12-01","The student, Ce Shi, accepted the attached license on 2018-12-10 at 17:20.","The student, Ce Shi, submitted this Thesis for approval on 2018-12-11 at 10:34.","This Thesis was approved for publication on 2018-12-12 at 16:19.","DSpace SAF Submission Ingestion Package generated from Vireo submission #13262 on 2019-02-07 at 14:23:07","Made available in DSpace on 2019-02-07T20:44:27Z (GMT). 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