Pub Date : 2023-11-21DOI: 10.1080/23744731.2023.2286195
André Quintã, Cheila Conceição, Nelson Martins, Jorge Ferreira
Conventional control strategies usually employed in tankless gas water heaters present difficulty in controlling the hot water temperature when subjected to sudden changes in water flow rate. Inade...
在无热式燃气热水器中，当水流突然变化时，采用的传统控制策略难以控制热水温度。Inade……
{"title":"Code Generation for Embedded Predictive Control of Gas Water Heaters","authors":"André Quintã, Cheila Conceição, Nelson Martins, Jorge Ferreira","doi":"10.1080/23744731.2023.2286195","DOIUrl":"https://doi.org/10.1080/23744731.2023.2286195","url":null,"abstract":"Conventional control strategies usually employed in tankless gas water heaters present difficulty in controlling the hot water temperature when subjected to sudden changes in water flow rate. Inade...","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"189 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138538064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-12DOI: 10.1080/23744731.2023.2279469
Aziz Mbaye, Massimo Cimmino
AbstractA new physics-based and modular variable refrigerant flow (VRF) heat pump model aimed towards multi-year simulations is presented. The model allows the simulation of any number of indoor units (IU), outdoor units (OU) and compressors. A parameter-estimation procedure and a control strategy both using available manufacturer data is proposed. The model is validated against data collected from a VRF system that services the first floor of the former ASHRAE Headquarters Building in Atlanta (USA), comprised of 22 indoor units, 2 outdoor units and 8 compressors. Results show that the model accurately predicts the total energy consumption over a 2-month cooling period, with a relative error, normalized mean bias error (NMBE), and coefficient of variation of the root mean square error (CVRMSE) of 1%, 1.6%, and 16.7%, respectively.Keywords: variable refrigerant flowheat pumpmodel calibrationcontroller emulationDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.
{"title":"Variable refrigerant flow heat pump model with estimated parameters and emulated controller based on manufacturer data","authors":"Aziz Mbaye, Massimo Cimmino","doi":"10.1080/23744731.2023.2279469","DOIUrl":"https://doi.org/10.1080/23744731.2023.2279469","url":null,"abstract":"AbstractA new physics-based and modular variable refrigerant flow (VRF) heat pump model aimed towards multi-year simulations is presented. The model allows the simulation of any number of indoor units (IU), outdoor units (OU) and compressors. A parameter-estimation procedure and a control strategy both using available manufacturer data is proposed. The model is validated against data collected from a VRF system that services the first floor of the former ASHRAE Headquarters Building in Atlanta (USA), comprised of 22 indoor units, 2 outdoor units and 8 compressors. Results show that the model accurately predicts the total energy consumption over a 2-month cooling period, with a relative error, normalized mean bias error (NMBE), and coefficient of variation of the root mean square error (CVRMSE) of 1%, 1.6%, and 16.7%, respectively.Keywords: variable refrigerant flowheat pumpmodel calibrationcontroller emulationDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"32 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135037599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-09DOI: 10.1080/23744731.2023.2279467
Daniel L. Villa, Sang Hoon Lee, Carlo Bianchi, Juan Pablo Carvallo, Illya Azaroff, Andrea Mammoli, Tyler Schostek
Heat waves are increasing in severity, duration, and frequency. The multi-scenario extreme weather simulator (MEWS) models this using historical data, climate model outputs, and heat wave multipliers. In this study, MEWS is applied for planning of a community resilience hub in Hau’ula, Hawaii. The hub will have normal operations and resilience operations modes. Both these modes were modelled using EnergyPlus. The resilience operations mode includes cutting off air-conditioning for many spaces to decrease power requirements during emergencies. Results were simulated for 300 future weather files generated by MEWS for 2020, 2040, 2060, and 2080. Shared socioeconomic pathways 2-4.5, 3-7.0 and 5-8.5 were used. The resilience operations mode results show two to six times increase of hours of exceedance beyond 32.2 °C from present conditions depending on climate scenario and future year. The resulting decrease in thermal resilience enables an average decrease of energy use intensity of 26% with little sensitivity to climate change. The decreased thermal resilience predicted in the future is undesirable, but was not severe enough to require a more energy intensive resilience mode. Instead, planning is needed to assure vulnerable individuals are given prioritized access to conditioned parts of the hub if worst case heat waves occur.
{"title":"Multi-scenario Extreme Weather Simulator Application to Heat Waves: Ko’olauloa Community Resilience Hub","authors":"Daniel L. Villa, Sang Hoon Lee, Carlo Bianchi, Juan Pablo Carvallo, Illya Azaroff, Andrea Mammoli, Tyler Schostek","doi":"10.1080/23744731.2023.2279467","DOIUrl":"https://doi.org/10.1080/23744731.2023.2279467","url":null,"abstract":"Heat waves are increasing in severity, duration, and frequency. The multi-scenario extreme weather simulator (MEWS) models this using historical data, climate model outputs, and heat wave multipliers. In this study, MEWS is applied for planning of a community resilience hub in Hau’ula, Hawaii. The hub will have normal operations and resilience operations modes. Both these modes were modelled using EnergyPlus. The resilience operations mode includes cutting off air-conditioning for many spaces to decrease power requirements during emergencies. Results were simulated for 300 future weather files generated by MEWS for 2020, 2040, 2060, and 2080. Shared socioeconomic pathways 2-4.5, 3-7.0 and 5-8.5 were used. The resilience operations mode results show two to six times increase of hours of exceedance beyond 32.2 °C from present conditions depending on climate scenario and future year. The resulting decrease in thermal resilience enables an average decrease of energy use intensity of 26% with little sensitivity to climate change. The decreased thermal resilience predicted in the future is undesirable, but was not severe enough to require a more energy intensive resilience mode. Instead, planning is needed to assure vulnerable individuals are given prioritized access to conditioned parts of the hub if worst case heat waves occur.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":" 22","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135243150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-08DOI: 10.1080/23744731.2023.2279466
Amanda L. Webb, Apoorv Khanuja
AbstractThe growth of legislation to reduce energy use in existing buildings is producing a rich new trove of data about energy efficiency measures (EEMs), which has the potential to unlock new insights into the built environment. However, the lack of standardized EEM naming conventions and categorization methods is currently a major barrier to aggregating and analyzing this data. The goal of this study was to develop and test a novel standardized system for categorizing EEMs. The system consists of two components: a three-level building element-based categorization hierarchy, and a set of measure name tags, which are used to label an EEM and categorize it on the hierarchy. A demonstration and testing process was developed and applied to two sample datasets to evaluate the ability of the system to categorize a variety of EEMs. The results show that most EEMs can easily be categorized manually according to the new system, and highlight several challenges for automated categorization, including EEM names that are missing an element, contain a term not in the tag list, or contain synonyms or abbreviations. These results provide a replicable and systematic framework for the translation, aggregation, and analysis of EEM datasets from different sources.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.
{"title":"Developing a standardized categorization system for energy efficiency measures (1836-RP)","authors":"Amanda L. Webb, Apoorv Khanuja","doi":"10.1080/23744731.2023.2279466","DOIUrl":"https://doi.org/10.1080/23744731.2023.2279466","url":null,"abstract":"AbstractThe growth of legislation to reduce energy use in existing buildings is producing a rich new trove of data about energy efficiency measures (EEMs), which has the potential to unlock new insights into the built environment. However, the lack of standardized EEM naming conventions and categorization methods is currently a major barrier to aggregating and analyzing this data. The goal of this study was to develop and test a novel standardized system for categorizing EEMs. The system consists of two components: a three-level building element-based categorization hierarchy, and a set of measure name tags, which are used to label an EEM and categorize it on the hierarchy. A demonstration and testing process was developed and applied to two sample datasets to evaluate the ability of the system to categorize a variety of EEMs. The results show that most EEMs can easily be categorized manually according to the new system, and highlight several challenges for automated categorization, including EEM names that are missing an element, contain a term not in the tag list, or contain synonyms or abbreviations. These results provide a replicable and systematic framework for the translation, aggregation, and analysis of EEM datasets from different sources.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"127 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135342031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-06DOI: 10.1080/23744731.2023.2279468
Gabrielle Beaudry, Philippe Pasquier, Alain Nguyen
AbstractFlowrate control can have a significant positive impact on the thermal performance and economic profitability of ground-source heat pump systems. Including dynamic advective processes in the design phase, however, remains a challenging task, as few computationally efficient modeling tools allow for their adequate and accurate representation. The present work addresses this issue by presenting new formulations of non-stationary convolutions, an efficient simulation algorithm that relies on the theory of linear time-variant systems for predicting the thermal response of a ground heat exchanger to both dynamic heat loads and flow rates. First, the new original formulations are presented, which include 1) a simple time-domain expression and 2) a fast frequency-domain expression. Then, the efficiency and validity of the new formulations are verified using experimental multi-flowrate thermal response tests involving dynamic circulation, pumping and bleed flow rates in closed-loop and standing column well ground heat exchangers. Results show that the new formulations can reproduce the outlet fluid temperature of both experimental test cases with good accuracy ( MAE=0.06∘C and 0.26∘C, respectively). At last, the high efficiency of the new frequency-domain expression is demonstrated, with the computing times (0.04 s and 0.01 s) being 100 and 8 times faster than the original formulation in both scenarios.Keywords: Ground-source heat pump systemtime-variant flowratessimulation of ground heat exchangernon-stationary convolutionDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.
{"title":"New formulations and experimental validation of non-stationary convolutions for the fast simulation of time-variant flowrates in ground heat exchangers","authors":"Gabrielle Beaudry, Philippe Pasquier, Alain Nguyen","doi":"10.1080/23744731.2023.2279468","DOIUrl":"https://doi.org/10.1080/23744731.2023.2279468","url":null,"abstract":"AbstractFlowrate control can have a significant positive impact on the thermal performance and economic profitability of ground-source heat pump systems. Including dynamic advective processes in the design phase, however, remains a challenging task, as few computationally efficient modeling tools allow for their adequate and accurate representation. The present work addresses this issue by presenting new formulations of non-stationary convolutions, an efficient simulation algorithm that relies on the theory of linear time-variant systems for predicting the thermal response of a ground heat exchanger to both dynamic heat loads and flow rates. First, the new original formulations are presented, which include 1) a simple time-domain expression and 2) a fast frequency-domain expression. Then, the efficiency and validity of the new formulations are verified using experimental multi-flowrate thermal response tests involving dynamic circulation, pumping and bleed flow rates in closed-loop and standing column well ground heat exchangers. Results show that the new formulations can reproduce the outlet fluid temperature of both experimental test cases with good accuracy ( MAE=0.06∘C and 0.26∘C, respectively). At last, the high efficiency of the new frequency-domain expression is demonstrated, with the computing times (0.04 s and 0.01 s) being 100 and 8 times faster than the original formulation in both scenarios.Keywords: Ground-source heat pump systemtime-variant flowratessimulation of ground heat exchangernon-stationary convolutionDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"82 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135678779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-03DOI: 10.1080/23744731.2023.2276011
Milica Grahovac, Paul Ehrlich, Jianjun Hu, Michael Wetter
ABSTRACTThe paper presents a comparative simulation-based control logic design process. It uses the Control Description Language (CDL) and the ASHRAE Guideline 36 high-performing building control sequences with the Modelica Buildings Library (MBL) to demonstrate a comparative analysis of two control designs for a data center chilled water plant.Details include a description of the closed-loop plant and control design methodology, including sizing and parameterization, base and alternative (Guideline 36) control logic with software implementation structure, and outline the simulation experimentation process. The selected control designs are paired with comparable chilled water plant configurations. The models include a chiller, a water-side economizer, and an evaporative cooling tower. The plant provides cooling at 27°C zone supply air temperature to a data center in Sacramento, CA, USA.The comparative simulation results examined the impacts of a selected control logic detail, and present an example model-based design application. Overall, the simulation results showed a 25% annual and a 18% summer energy use reduction for alternative controls.This shows that simulation-based control logic design performance evaluation can improve energy efficiency and resilience aspects of system controls at large.Units and additional abbreviations are provided directly in the text where needed.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.
{"title":"Model-based Data Center Cooling Controls Comparative Co-design","authors":"Milica Grahovac, Paul Ehrlich, Jianjun Hu, Michael Wetter","doi":"10.1080/23744731.2023.2276011","DOIUrl":"https://doi.org/10.1080/23744731.2023.2276011","url":null,"abstract":"ABSTRACTThe paper presents a comparative simulation-based control logic design process. It uses the Control Description Language (CDL) and the ASHRAE Guideline 36 high-performing building control sequences with the Modelica Buildings Library (MBL) to demonstrate a comparative analysis of two control designs for a data center chilled water plant.Details include a description of the closed-loop plant and control design methodology, including sizing and parameterization, base and alternative (Guideline 36) control logic with software implementation structure, and outline the simulation experimentation process. The selected control designs are paired with comparable chilled water plant configurations. The models include a chiller, a water-side economizer, and an evaporative cooling tower. The plant provides cooling at 27°C zone supply air temperature to a data center in Sacramento, CA, USA.The comparative simulation results examined the impacts of a selected control logic detail, and present an example model-based design application. Overall, the simulation results showed a 25% annual and a 18% summer energy use reduction for alternative controls.This shows that simulation-based control logic design performance evaluation can improve energy efficiency and resilience aspects of system controls at large.Units and additional abbreviations are provided directly in the text where needed.DisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"54 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135868038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.1080/23744731.2023.2276012
Max St-Jacques, Scott Bucking, William O'Brien, Iain MacDonald
{"title":"Spatio-temporal electrical grid emission factors effects on calculated GHG emissions of buildings in mixed-grid environments","authors":"Max St-Jacques, Scott Bucking, William O'Brien, Iain MacDonald","doi":"10.1080/23744731.2023.2276012","DOIUrl":"https://doi.org/10.1080/23744731.2023.2276012","url":null,"abstract":"","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"93 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136103792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.1080/23744731.2023.2277113
None Alexandre Noël, Massimo Cimmino
{"title":"Topology optimization of geothermal bore fields using the method of moving asymptotes","authors":"None Alexandre Noël, Massimo Cimmino","doi":"10.1080/23744731.2023.2277113","DOIUrl":"https://doi.org/10.1080/23744731.2023.2277113","url":null,"abstract":"","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"9 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136104100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-26DOI: 10.1080/23744731.2023.2276010
Joshua Rothe, Jerin Robins Ebanesar, Lorenzo Cremaschi
AbstractWith new low-GWP HFO refrigerants, the heat transfer performances and methods for decreasing system refrigerant inventory are receiving increasing interest. In shell-and-tube heat exchangers, refrigerant distribution via pressurized liquid spray has the potential for high heat transfer performance while reducing refrigerant charge. However, no published studies have investigated LGWP refrigerants with spray evaporation on tube bundles. A test apparatus was constructed to measure the shell-side heat transfer coefficients of R1234ze(E) on bundles of tubes with two different enhanced-surface types and in two different bundle geometries at various refrigerant saturation temperatures. The results showed strong dependence on refrigerant properties, tube heat flux, enhanced-surface type, bundle geometry, and refrigerant inlet subcooling. The bundle heat transfer coefficients of R1234ze(E) were similar to that of R134a in the same test setup, usually within ±15% for similar conditions. In both cases, they first increased with the heat flux until a local maximum value was achieved. A localized dryout of the tubes at the bottom of the bundle penalized the overall bundle heat transfer coefficient at very high heat flux. For the condensing surface, bundle heat transfer coefficients rarely exceeded 10 kW/m2-K, whereas values in excess of 30 kW/m2-K were sometimes seen for the evaporating surface.Keywords: LGWP refrigerantsspray evaporationenhanced surfacestube bundlesSubject classification codes: include these here if the journal requires themDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.
{"title":"Tube Bundle Evaporators with LGWP Refrigerant R1234ze(E)","authors":"Joshua Rothe, Jerin Robins Ebanesar, Lorenzo Cremaschi","doi":"10.1080/23744731.2023.2276010","DOIUrl":"https://doi.org/10.1080/23744731.2023.2276010","url":null,"abstract":"AbstractWith new low-GWP HFO refrigerants, the heat transfer performances and methods for decreasing system refrigerant inventory are receiving increasing interest. In shell-and-tube heat exchangers, refrigerant distribution via pressurized liquid spray has the potential for high heat transfer performance while reducing refrigerant charge. However, no published studies have investigated LGWP refrigerants with spray evaporation on tube bundles. A test apparatus was constructed to measure the shell-side heat transfer coefficients of R1234ze(E) on bundles of tubes with two different enhanced-surface types and in two different bundle geometries at various refrigerant saturation temperatures. The results showed strong dependence on refrigerant properties, tube heat flux, enhanced-surface type, bundle geometry, and refrigerant inlet subcooling. The bundle heat transfer coefficients of R1234ze(E) were similar to that of R134a in the same test setup, usually within ±15% for similar conditions. In both cases, they first increased with the heat flux until a local maximum value was achieved. A localized dryout of the tubes at the bottom of the bundle penalized the overall bundle heat transfer coefficient at very high heat flux. For the condensing surface, bundle heat transfer coefficients rarely exceeded 10 kW/m2-K, whereas values in excess of 30 kW/m2-K were sometimes seen for the evaporating surface.Keywords: LGWP refrigerantsspray evaporationenhanced surfacestube bundlesSubject classification codes: include these here if the journal requires themDisclaimerAs a service to authors and researchers we are providing this version of an accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proofs will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also.","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"88 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136376667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-21DOI: 10.1080/23744731.2023.2273660
Kristen Cetin, Brian M. Fronk
{"title":"Broadening participation in ASHRAE conferences: Innovative research in the built environment presented at the 2022 ASHRAE Annual Conference","authors":"Kristen Cetin, Brian M. Fronk","doi":"10.1080/23744731.2023.2273660","DOIUrl":"https://doi.org/10.1080/23744731.2023.2273660","url":null,"abstract":"","PeriodicalId":21556,"journal":{"name":"Science and Technology for the Built Environment","volume":"38 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135513875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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