{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/78537"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/78537","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Experimental study of reversible AC/HP system for electric vehicles","abstract":"Conventional passenger cars use waste heat from internal combustion engine for cabin heating. While for electric vehicles (EV), the energy conversion efficiency is much higher, so that there isn't much waste heat available for cabin heating. A general way to provide heat for EV is to use a positive temperature coefficient (PTC) heater to convert electricity stored in the battery directly into heat by Joule effect. Although electric heaters usually have almost 100% first law efficiency, their second law efficiency is typically very low. For a common electric car, turning on the PTC heater can drain the battery and decrease the drive range dramatically. A heat pump is an alternative way to provide equivalent amount of heat for the cabin with less electric energy consumption due to its higher second law efficiency, and will reduce the drive range reduction of EVs caused by cabin heating. Vapor compression cycle is commonly used for automotive air conditioning. By moderate modification of the air conditioning system, heat pump function can be obtained. A heat pump test setup has been built in the lab based on the heat pump system from a commercially available EV, with necessary measurement instrumentation added. Heating capacity (Q) and heating performance factor (HPF) are the most important performance parameters of the heat pump system. The system characteristics and steady state performance have been studied according to different system parameters including expansion valve opening size, refrigerant charge amount, compressor speed, indoor air mass flow rate, outdoor air face velocity, and ambient and indoor temperatures. The transient behavior can be simulated by using steady state test results for different indoor temperature at each ambient condition. Subcooling control for maximizing HPF and charge imbalance and migration are investigated. Challenges with the current system and opportunities for further study are discussed.","abstract_html":"Conventional passenger cars use waste heat from internal combustion engine for cabin heating. While for electric vehicles (EV), the energy conversion efficiency is much higher, so that there isn't much waste heat available for cabin heating. A general way to provide heat for EV is to use a positive temperature coefficient (PTC) heater to convert electricity stored in the battery directly into heat by Joule effect. Although electric heaters usually have almost 100% first law efficiency, their second law efficiency is typically very low. For a common electric car, turning on the PTC heater can drain the battery and decrease the drive range dramatically. A heat pump is an alternative way to provide equivalent amount of heat for the cabin with less electric energy consumption due to its higher second law efficiency, and will reduce the drive range reduction of EVs caused by cabin heating. Vapor compression cycle is commonly used for automotive air conditioning. By moderate modification of the air conditioning system, heat pump function can be obtained. A heat pump test setup has been built in the lab based on the heat pump system from a commercially available EV, with necessary measurement instrumentation added. Heating capacity (Q) and heating performance factor (HPF) are the most important performance parameters of the heat pump system. The system characteristics and steady state performance have been studied according to different system parameters including expansion valve opening size, refrigerant charge amount, compressor speed, indoor air mass flow rate, outdoor air face velocity, and ambient and indoor temperatures. The transient behavior can be simulated by using steady state test results for different indoor temperature at each ambient condition. Subcooling control for maximizing HPF and charge imbalance and migration are investigated. Challenges with the current system and opportunities for further study are discussed.","abstract_has_math":false,"creators":["Feng, Lili"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-07-22T22:18:02Z","date_published":"2015-07-22T22:18:02Z","updated_at":"2026-07-22T22:26:11Z","subjects":["automotive heat pump","reversible system","electric vehicles"],"languages":["en"],"rights":["Copyright 2015 Lili Feng"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/78537","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Feng, Lili"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-07-22T22:18:02Z","2015-05","2015-04-29","2015-5"]},{"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":["automotive heat pump","reversible system","electric vehicles"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2015 Lili Feng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/78537"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Conventional passenger cars use waste heat from internal combustion engine for cabin heating. While for electric vehicles (EV), the energy conversion efficiency is much higher, so that there isn't much waste heat available for cabin heating. A general way to provide heat for EV is to use a positive temperature coefficient (PTC) heater to convert electricity stored in the battery directly into heat by Joule effect. Although electric heaters usually have almost 100% first law efficiency, their second law efficiency is typically very low. For a common electric car, turning on the PTC heater can drain the battery and decrease the drive range dramatically. A heat pump is an alternative way to provide equivalent amount of heat for the cabin with less electric energy consumption due to its higher second law efficiency, and will reduce the drive range reduction of EVs caused by cabin heating. Vapor compression cycle is commonly used for automotive air conditioning. By moderate modification of the air conditioning system, heat pump function can be obtained. A heat pump test setup has been built in the lab based on the heat pump system from a commercially available EV, with necessary measurement instrumentation added. Heating capacity (Q) and heating performance factor (HPF) are the most important performance parameters of the heat pump system. The system characteristics and steady state performance have been studied according to different system parameters including expansion valve opening size, refrigerant charge amount, compressor speed, indoor air mass flow rate, outdoor air face velocity, and ambient and indoor temperatures. The transient behavior can be simulated by using steady state test results for different indoor temperature at each ambient condition. Subcooling control for maximizing HPF and charge imbalance and migration are investigated. Challenges with the current system and opportunities for further study are discussed.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-07-22 without embargo terms","The student, Lili Feng, accepted the attached license on 2015-04-28 at 20:04.","The student, Lili Feng, submitted this Thesis for approval on 2015-04-28 at 20:13.","This Thesis was approved for publication on 2015-04-29 at 15:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8171 on 2015-07-22 at 10:34:40","Made available in DSpace on 2015-07-22T22:18:02Z (GMT). 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Although electric heaters usually have almost 100% first law efficiency, their second law efficiency is typically very low. For a common electric car, turning on the PTC heater can drain the battery and decrease the drive range dramatically. A heat pump is an alternative way to provide equivalent amount of heat for the cabin with less electric energy consumption due to its higher second law efficiency, and will reduce the drive range reduction of EVs caused by cabin heating. Vapor compression cycle is commonly used for automotive air conditioning. By moderate modification of the air conditioning system, heat pump function can be obtained. A heat pump test setup has been built in the lab based on the heat pump system from a commercially available EV, with necessary measurement instrumentation added. Heating capacity (Q) and heating performance factor (HPF) are the most important performance parameters of the heat pump system. The system characteristics and steady state performance have been studied according to different system parameters including expansion valve opening size, refrigerant charge amount, compressor speed, indoor air mass flow rate, outdoor air face velocity, and ambient and indoor temperatures. The transient behavior can be simulated by using steady state test results for different indoor temperature at each ambient condition. Subcooling control for maximizing HPF and charge imbalance and migration are investigated. Challenges with the current system and opportunities for further study are discussed.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-07-22 without embargo terms","The student, Lili Feng, accepted the attached license on 2015-04-28 at 20:04.","The student, Lili Feng, submitted this Thesis for approval on 2015-04-28 at 20:13.","This Thesis was approved for publication on 2015-04-29 at 15:41.","DSpace SAF Submission Ingestion Package generated from Vireo submission #8171 on 2015-07-22 at 10:34:40","Made available in DSpace on 2015-07-22T22:18:02Z (GMT). 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