Use of desiccant dehumidification to improve energy utilization in air-conditioning systems in Beirut
Humidity and indoor moist surrounding affect air cleanliness and protects harmful microorganisms when relative humidity is above 70%. In humid climates, the humidity issues are a major contributor to energy inefficiency in HVAC devices. The use of liquid desiccant dehumidification systems of supply...
Gespeichert in:
Veröffentlicht in: | International journal of energy research 2003-12, Vol.27 (15), p.1317-1338 |
---|---|
Hauptverfasser: | , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
container_end_page | 1338 |
---|---|
container_issue | 15 |
container_start_page | 1317 |
container_title | International journal of energy research |
container_volume | 27 |
creator | Ghaddar, Nesreen Ghali, Kamel Najm, Antoine |
description | Humidity and indoor moist surrounding affect air cleanliness and protects harmful microorganisms when relative humidity is above 70%. In humid climates, the humidity issues are a major contributor to energy inefficiency in HVAC devices. The use of liquid desiccant dehumidification systems of supply air is a viable alternative to reduce the latent heat load on the HVAC system and improve efficiency. Thermal energy, at a temperature as low as 40–50°C, required for the operation of a liquid desiccant hybrid air conditioner can be efficiently obtained using a flat‐plate solar collector.
In this work a model of a solar‐operated liquid desiccant system (using calcium Chloride) for air dehumidification is developed. The system utilizes packed beds of counter flow between an air stream and a solution of liquid desiccant for air dehumidification and solution regeneration. The desiccant system model is integrated with a solar heat source for performance evaluation at a wide range of recorded ambient conditions for Beirut city. Standard mass and energy balances are performed on the various components of the system and a computer simulation program is developed for the integrated system analysis.
The desiccant system of the current study replaces a 3 TR (10.56 kW) vapour compression unit for a typical house as low latent load application, and is part of a hybrid desiccant–vapour compression system for a high latent load application, namely a small restaurant with an estimated cooling load of 11.39 TR (40 kW), including reheat. The relevant parameters of the desiccant system are optimized at peak load, and it is found out that there is an important energy saving if the ratio of the air flow rate in the regenerator to that in the dehumidifier is about 0.3 to 0.4. The COP of the desiccant unit is 0.41 for the house, and 0.45 for the restaurant. The size of the vapor compression unit of the restaurant is reduced to 8 TR when supplemented by a desiccant system.
The performance is studied of the desiccant system integrated with a solar collector system and an auxiliary natural gas heater to heat the regenerator. The transient simulation of the solar desiccant system is performed for the entire cooling season. The solar fraction for the house is equal to 0.25, 0.47, and 0.68 for a collector area of 28.72, 57.44, and 86.16 m2, respectively. The solar fraction for the restaurant is 0.19, 0.38, and 0.54, for the same collector areas. The life cycle savings for the house run sol |
doi_str_mv | 10.1002/er.945 |
format | Article |
fullrecord | <record><control><sourceid>proquest_cross</sourceid><recordid>TN_cdi_proquest_miscellaneous_27975026</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>21286629</sourcerecordid><originalsourceid>FETCH-LOGICAL-c3855-4e19a85c0cc21814f305bfee1de901b04abe333b57c872d9a9908b0a22fde64f3</originalsourceid><addsrcrecordid>eNqFkE1P3DAQhq2KSl1o-xtyKRKH0LEdJ_YRFgpIq35pUVEvluNM6JR8LHbSdvvrm1UQnCpOHvl99MzoZewth2MOIN5jODaZesEWHIxJOc9u9tgCZC5TA8XNK7Yf40-AKePFguF1xKSvkwojee-6YZp-jC1VVJN3A_VdMvQJtZvQ_8IEOwy322QcqKG_c0pd4iikvu8q2n1Qd5vEbRywjbvsFCmMw2v2snZNxDcP7wG7_nC-Xl6mq08XV8uTVeqlVirNkBunlQfvBdc8qyWoskbkFRrgJWSuRCllqQqvC1EZZwzoEpwQdYX5hB-ww9k7nXs_YhxsS9Fj07gO-zFaUZhCgcifB7nQeS7ME-hDH2PA2m4CtS5sLQe7q9tisFPdE_juweiid00dXOcpPtFKguZ6t_lo5n5Tg9v_2Oz519mZzixNff55ZF24s3khC2W_fbyw379ky7PP61Or5T9yj51e</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype><pqid>21286629</pqid></control><display><type>article</type><title>Use of desiccant dehumidification to improve energy utilization in air-conditioning systems in Beirut</title><source>Access via Wiley Online Library</source><creator>Ghaddar, Nesreen ; Ghali, Kamel ; Najm, Antoine</creator><creatorcontrib>Ghaddar, Nesreen ; Ghali, Kamel ; Najm, Antoine</creatorcontrib><description>Humidity and indoor moist surrounding affect air cleanliness and protects harmful microorganisms when relative humidity is above 70%. In humid climates, the humidity issues are a major contributor to energy inefficiency in HVAC devices. The use of liquid desiccant dehumidification systems of supply air is a viable alternative to reduce the latent heat load on the HVAC system and improve efficiency. Thermal energy, at a temperature as low as 40–50°C, required for the operation of a liquid desiccant hybrid air conditioner can be efficiently obtained using a flat‐plate solar collector.
In this work a model of a solar‐operated liquid desiccant system (using calcium Chloride) for air dehumidification is developed. The system utilizes packed beds of counter flow between an air stream and a solution of liquid desiccant for air dehumidification and solution regeneration. The desiccant system model is integrated with a solar heat source for performance evaluation at a wide range of recorded ambient conditions for Beirut city. Standard mass and energy balances are performed on the various components of the system and a computer simulation program is developed for the integrated system analysis.
The desiccant system of the current study replaces a 3 TR (10.56 kW) vapour compression unit for a typical house as low latent load application, and is part of a hybrid desiccant–vapour compression system for a high latent load application, namely a small restaurant with an estimated cooling load of 11.39 TR (40 kW), including reheat. The relevant parameters of the desiccant system are optimized at peak load, and it is found out that there is an important energy saving if the ratio of the air flow rate in the regenerator to that in the dehumidifier is about 0.3 to 0.4. The COP of the desiccant unit is 0.41 for the house, and 0.45 for the restaurant. The size of the vapor compression unit of the restaurant is reduced to 8 TR when supplemented by a desiccant system.
The performance is studied of the desiccant system integrated with a solar collector system and an auxiliary natural gas heater to heat the regenerator. The transient simulation of the solar desiccant system is performed for the entire cooling season. The solar fraction for the house is equal to 0.25, 0.47, and 0.68 for a collector area of 28.72, 57.44, and 86.16 m2, respectively. The solar fraction for the restaurant is 0.19, 0.38, and 0.54, for the same collector areas. The life cycle savings for the house run solely on desiccant system were positive only if natural gas is available at a cheap price. For the restaurant, the economic benefit of the desiccant system is positive, because the need for reheat in the vapor compression system is eliminated. For a gas price of 0.5638 $/kg, the payback period for the restaurant turned out to be immediate if the energy is supplied solely by natural gas, and 11 years if an 86.16 m2 solar collector is implemented to reduce the fuel consumption. Copyright © 2003 John Wiley & Sons, Ltd.</description><identifier>ISSN: 0363-907X</identifier><identifier>EISSN: 1099-114X</identifier><identifier>DOI: 10.1002/er.945</identifier><identifier>CODEN: IJERDN</identifier><language>eng</language><publisher>Chichester, UK: John Wiley & Sons, Ltd</publisher><subject>Air conditioning. Ventilation ; Air treatment ; Applied sciences ; dehumidification ; Energy ; energy efficiency ; Energy. Thermal use of fuels ; Exact sciences and technology ; Heating, air conditioning and ventilation ; liquid desiccant cooling system ; solar-assisted air-conditioning</subject><ispartof>International journal of energy research, 2003-12, Vol.27 (15), p.1317-1338</ispartof><rights>Copyright © 2003 John Wiley & Sons, Ltd.</rights><rights>2004 INIST-CNRS</rights><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><citedby>FETCH-LOGICAL-c3855-4e19a85c0cc21814f305bfee1de901b04abe333b57c872d9a9908b0a22fde64f3</citedby><cites>FETCH-LOGICAL-c3855-4e19a85c0cc21814f305bfee1de901b04abe333b57c872d9a9908b0a22fde64f3</cites></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><linktopdf>$$Uhttps://onlinelibrary.wiley.com/doi/pdf/10.1002%2Fer.945$$EPDF$$P50$$Gwiley$$H</linktopdf><linktohtml>$$Uhttps://onlinelibrary.wiley.com/doi/full/10.1002%2Fer.945$$EHTML$$P50$$Gwiley$$H</linktohtml><link.rule.ids>314,780,784,1417,27924,27925,45574,45575</link.rule.ids><backlink>$$Uhttp://pascal-francis.inist.fr/vibad/index.php?action=getRecordDetail&idt=15308186$$DView record in Pascal Francis$$Hfree_for_read</backlink></links><search><creatorcontrib>Ghaddar, Nesreen</creatorcontrib><creatorcontrib>Ghali, Kamel</creatorcontrib><creatorcontrib>Najm, Antoine</creatorcontrib><title>Use of desiccant dehumidification to improve energy utilization in air-conditioning systems in Beirut</title><title>International journal of energy research</title><addtitle>Int. J. Energy Res</addtitle><description>Humidity and indoor moist surrounding affect air cleanliness and protects harmful microorganisms when relative humidity is above 70%. In humid climates, the humidity issues are a major contributor to energy inefficiency in HVAC devices. The use of liquid desiccant dehumidification systems of supply air is a viable alternative to reduce the latent heat load on the HVAC system and improve efficiency. Thermal energy, at a temperature as low as 40–50°C, required for the operation of a liquid desiccant hybrid air conditioner can be efficiently obtained using a flat‐plate solar collector.
In this work a model of a solar‐operated liquid desiccant system (using calcium Chloride) for air dehumidification is developed. The system utilizes packed beds of counter flow between an air stream and a solution of liquid desiccant for air dehumidification and solution regeneration. The desiccant system model is integrated with a solar heat source for performance evaluation at a wide range of recorded ambient conditions for Beirut city. Standard mass and energy balances are performed on the various components of the system and a computer simulation program is developed for the integrated system analysis.
The desiccant system of the current study replaces a 3 TR (10.56 kW) vapour compression unit for a typical house as low latent load application, and is part of a hybrid desiccant–vapour compression system for a high latent load application, namely a small restaurant with an estimated cooling load of 11.39 TR (40 kW), including reheat. The relevant parameters of the desiccant system are optimized at peak load, and it is found out that there is an important energy saving if the ratio of the air flow rate in the regenerator to that in the dehumidifier is about 0.3 to 0.4. The COP of the desiccant unit is 0.41 for the house, and 0.45 for the restaurant. The size of the vapor compression unit of the restaurant is reduced to 8 TR when supplemented by a desiccant system.
The performance is studied of the desiccant system integrated with a solar collector system and an auxiliary natural gas heater to heat the regenerator. The transient simulation of the solar desiccant system is performed for the entire cooling season. The solar fraction for the house is equal to 0.25, 0.47, and 0.68 for a collector area of 28.72, 57.44, and 86.16 m2, respectively. The solar fraction for the restaurant is 0.19, 0.38, and 0.54, for the same collector areas. The life cycle savings for the house run solely on desiccant system were positive only if natural gas is available at a cheap price. For the restaurant, the economic benefit of the desiccant system is positive, because the need for reheat in the vapor compression system is eliminated. For a gas price of 0.5638 $/kg, the payback period for the restaurant turned out to be immediate if the energy is supplied solely by natural gas, and 11 years if an 86.16 m2 solar collector is implemented to reduce the fuel consumption. Copyright © 2003 John Wiley & Sons, Ltd.</description><subject>Air conditioning. Ventilation</subject><subject>Air treatment</subject><subject>Applied sciences</subject><subject>dehumidification</subject><subject>Energy</subject><subject>energy efficiency</subject><subject>Energy. Thermal use of fuels</subject><subject>Exact sciences and technology</subject><subject>Heating, air conditioning and ventilation</subject><subject>liquid desiccant cooling system</subject><subject>solar-assisted air-conditioning</subject><issn>0363-907X</issn><issn>1099-114X</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2003</creationdate><recordtype>article</recordtype><recordid>eNqFkE1P3DAQhq2KSl1o-xtyKRKH0LEdJ_YRFgpIq35pUVEvluNM6JR8LHbSdvvrm1UQnCpOHvl99MzoZewth2MOIN5jODaZesEWHIxJOc9u9tgCZC5TA8XNK7Yf40-AKePFguF1xKSvkwojee-6YZp-jC1VVJN3A_VdMvQJtZvQ_8IEOwy322QcqKG_c0pd4iikvu8q2n1Qd5vEbRywjbvsFCmMw2v2snZNxDcP7wG7_nC-Xl6mq08XV8uTVeqlVirNkBunlQfvBdc8qyWoskbkFRrgJWSuRCllqQqvC1EZZwzoEpwQdYX5hB-ww9k7nXs_YhxsS9Fj07gO-zFaUZhCgcifB7nQeS7ME-hDH2PA2m4CtS5sLQe7q9tisFPdE_juweiid00dXOcpPtFKguZ6t_lo5n5Tg9v_2Oz519mZzixNff55ZF24s3khC2W_fbyw379ky7PP61Or5T9yj51e</recordid><startdate>200312</startdate><enddate>200312</enddate><creator>Ghaddar, Nesreen</creator><creator>Ghali, Kamel</creator><creator>Najm, Antoine</creator><general>John Wiley & Sons, Ltd</general><general>Wiley</general><scope>BSCLL</scope><scope>IQODW</scope><scope>AAYXX</scope><scope>CITATION</scope><scope>7T7</scope><scope>8FD</scope><scope>C1K</scope><scope>FR3</scope><scope>P64</scope><scope>F28</scope></search><sort><creationdate>200312</creationdate><title>Use of desiccant dehumidification to improve energy utilization in air-conditioning systems in Beirut</title><author>Ghaddar, Nesreen ; Ghali, Kamel ; Najm, Antoine</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c3855-4e19a85c0cc21814f305bfee1de901b04abe333b57c872d9a9908b0a22fde64f3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2003</creationdate><topic>Air conditioning. Ventilation</topic><topic>Air treatment</topic><topic>Applied sciences</topic><topic>dehumidification</topic><topic>Energy</topic><topic>energy efficiency</topic><topic>Energy. Thermal use of fuels</topic><topic>Exact sciences and technology</topic><topic>Heating, air conditioning and ventilation</topic><topic>liquid desiccant cooling system</topic><topic>solar-assisted air-conditioning</topic><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Ghaddar, Nesreen</creatorcontrib><creatorcontrib>Ghali, Kamel</creatorcontrib><creatorcontrib>Najm, Antoine</creatorcontrib><collection>Istex</collection><collection>Pascal-Francis</collection><collection>CrossRef</collection><collection>Industrial and Applied Microbiology Abstracts (Microbiology A)</collection><collection>Technology Research Database</collection><collection>Environmental Sciences and Pollution Management</collection><collection>Engineering Research Database</collection><collection>Biotechnology and BioEngineering Abstracts</collection><collection>ANTE: Abstracts in New Technology & Engineering</collection><jtitle>International journal of energy research</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Ghaddar, Nesreen</au><au>Ghali, Kamel</au><au>Najm, Antoine</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Use of desiccant dehumidification to improve energy utilization in air-conditioning systems in Beirut</atitle><jtitle>International journal of energy research</jtitle><addtitle>Int. J. Energy Res</addtitle><date>2003-12</date><risdate>2003</risdate><volume>27</volume><issue>15</issue><spage>1317</spage><epage>1338</epage><pages>1317-1338</pages><issn>0363-907X</issn><eissn>1099-114X</eissn><coden>IJERDN</coden><abstract>Humidity and indoor moist surrounding affect air cleanliness and protects harmful microorganisms when relative humidity is above 70%. In humid climates, the humidity issues are a major contributor to energy inefficiency in HVAC devices. The use of liquid desiccant dehumidification systems of supply air is a viable alternative to reduce the latent heat load on the HVAC system and improve efficiency. Thermal energy, at a temperature as low as 40–50°C, required for the operation of a liquid desiccant hybrid air conditioner can be efficiently obtained using a flat‐plate solar collector.
In this work a model of a solar‐operated liquid desiccant system (using calcium Chloride) for air dehumidification is developed. The system utilizes packed beds of counter flow between an air stream and a solution of liquid desiccant for air dehumidification and solution regeneration. The desiccant system model is integrated with a solar heat source for performance evaluation at a wide range of recorded ambient conditions for Beirut city. Standard mass and energy balances are performed on the various components of the system and a computer simulation program is developed for the integrated system analysis.
The desiccant system of the current study replaces a 3 TR (10.56 kW) vapour compression unit for a typical house as low latent load application, and is part of a hybrid desiccant–vapour compression system for a high latent load application, namely a small restaurant with an estimated cooling load of 11.39 TR (40 kW), including reheat. The relevant parameters of the desiccant system are optimized at peak load, and it is found out that there is an important energy saving if the ratio of the air flow rate in the regenerator to that in the dehumidifier is about 0.3 to 0.4. The COP of the desiccant unit is 0.41 for the house, and 0.45 for the restaurant. The size of the vapor compression unit of the restaurant is reduced to 8 TR when supplemented by a desiccant system.
The performance is studied of the desiccant system integrated with a solar collector system and an auxiliary natural gas heater to heat the regenerator. The transient simulation of the solar desiccant system is performed for the entire cooling season. The solar fraction for the house is equal to 0.25, 0.47, and 0.68 for a collector area of 28.72, 57.44, and 86.16 m2, respectively. The solar fraction for the restaurant is 0.19, 0.38, and 0.54, for the same collector areas. The life cycle savings for the house run solely on desiccant system were positive only if natural gas is available at a cheap price. For the restaurant, the economic benefit of the desiccant system is positive, because the need for reheat in the vapor compression system is eliminated. For a gas price of 0.5638 $/kg, the payback period for the restaurant turned out to be immediate if the energy is supplied solely by natural gas, and 11 years if an 86.16 m2 solar collector is implemented to reduce the fuel consumption. Copyright © 2003 John Wiley & Sons, Ltd.</abstract><cop>Chichester, UK</cop><pub>John Wiley & Sons, Ltd</pub><doi>10.1002/er.945</doi><tpages>22</tpages></addata></record> |
fulltext | fulltext |
identifier | ISSN: 0363-907X |
ispartof | International journal of energy research, 2003-12, Vol.27 (15), p.1317-1338 |
issn | 0363-907X 1099-114X |
language | eng |
recordid | cdi_proquest_miscellaneous_27975026 |
source | Access via Wiley Online Library |
subjects | Air conditioning. Ventilation Air treatment Applied sciences dehumidification Energy energy efficiency Energy. Thermal use of fuels Exact sciences and technology Heating, air conditioning and ventilation liquid desiccant cooling system solar-assisted air-conditioning |
title | Use of desiccant dehumidification to improve energy utilization in air-conditioning systems in Beirut |
url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2024-12-25T15%3A22%3A45IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-proquest_cross&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Use%20of%20desiccant%20dehumidification%20to%20improve%20energy%20utilization%20in%20air-conditioning%20systems%20in%20Beirut&rft.jtitle=International%20journal%20of%20energy%20research&rft.au=Ghaddar,%20Nesreen&rft.date=2003-12&rft.volume=27&rft.issue=15&rft.spage=1317&rft.epage=1338&rft.pages=1317-1338&rft.issn=0363-907X&rft.eissn=1099-114X&rft.coden=IJERDN&rft_id=info:doi/10.1002/er.945&rft_dat=%3Cproquest_cross%3E21286629%3C/proquest_cross%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_pqid=21286629&rft_id=info:pmid/&rfr_iscdi=true |