The Experts below are selected from a list of 1362 Experts worldwide ranked by ideXlab platform
Gershon Grossman - One of the best experts on this subject based on the ideXlab platform.
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Experimental comparison between internally and externally cooled air-solution contactors
Science and Technology for the Built Environment, 2015Co-Authors: Khaled Gommed, Gershon Grossman, Juan Prieto, Jordi Ortiga, Alberto CoronasAbstract:Air-conditioning demand, especially in hot and humid climates, causes most of the energy consumption in buildings. In these applications, the latent load often constitutes a significant part of the total load. Conventional air-conditioning Systems deal with the required dehumidification by cooling the moist air below its dew point and reheat it later to increase its temperature to comfortable supply conditions. By using solid/liquid Desiccant Systems, which absorb humidity from the air, it becomes unnecessary to reach the dew point to dehumidify, thereby reducing energy consumption. In liquid Desiccant Systems, dehumidification occurs in the absorber, where the humidity of the air is absorbed by direct contact with a Desiccant. Most of the previous liquid Desiccant System studies have used adiabatic absorbers, where the solution must be cooled externally before being delivered into the air-solution contactor. However, based on experience with closed-cycle absorption Systems, internally cooled absorbers ar...
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Investigation of an improved solar-powered open absorption System for cooling, dehumidification and air conditioning
International Journal of Refrigeration, 2012Co-Authors: Khaled Gommed, Gershon GrossmanAbstract:This study is concerned with an open absorption (liquid Desiccant) System, capable of producing both cooling and dehumidification for air conditioning, utilizing low-grade heat. The System includes a novel solution heat and mass exchanger (HME) designed to serve as a Desiccant solution reservoir for both the absorber and desorber, enabling mass transfer between them with minimum heat transfer losses and eliminating the need for an external recuperative heat exchanger. The use of this new HME together with an improved solution flow arrangement in the new System facilitates the use of adiabatic absorption/desorption with minimum circulation heat losses and wetting problems. The characteristic performance of the System was studied under varying operating conditions. The use of the new HME has fulfilled the objective of reducing the time constant of the System, helped correct idling and level control problems and ensures maximum solution concentration on the absorber side during desorber operation. ?? 2012 Elsevier Ltd and IIR. All rights reserved.
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Open cycle absorption and Desiccant technology
International Sorption Heat Pumpe Conference, 2011Co-Authors: Gershon GrossmanAbstract:Increasing demand for air conditioning in the world has caused a growing burden on available energy resources, and particularly on the supply of electric power. Desiccant Systems for cooling and dehumidification stand as a good alternative to conventional electric-powered cooling Systems. They are capable of using low-grade heat such as industrial waste heat or so- lar heat from low-cost flat plate collectors as their source of power, and have the potential to provide both cooling and dehumidification, as required by the load. Desiccant Systems are ex- ceptionally good at dehumidification, thereby taking care of the latent heat load. This article aims to describe the technology of Desiccant Systems for HVAC applications. The principles of operation of the Desiccant System (also known as open-cycle absorp- tion/adsorption) are explained. The types of Desiccants suitable for air conditioning Systems are surveyed. A description of Desiccant Systems, both solid and liquid, is given, with the equipment used in their practical implementation.
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Experimental investigation of a liquid Desiccant System for solar cooling and dehumidification
Solar Energy, 2007Co-Authors: Khaled Gommed, Gershon GrossmanAbstract:Growing demand for air conditioning in recent years has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the environmentally-friendly techniques which may help alleviate the problem. A promising solar cooling method is through the use of a liquid Desiccant System, where humidity is absorbed directly from the process air by direct contact with the Desiccant. The Desiccant is then regenerated, again in direct contact with an external air stream, by solar heat at relatively low temperatures. The liquid Desiccant System has many potential advantages over other solar air conditioning Systems and can provide a promising alternative to absorption or to solid Desiccant Systems. Earlier work by the authors included theoretical simulations and preliminary experiments on the key components of the liquid Desiccant System. The objective of the present study has been to construct a prototype System based on the knowledge gained, to monitor its performance, identify problems and carry out preliminary design optimization. A 16 kWt System was installed at the Energy Engineering Center at the Technion, in the Mediterranean city of Haifa. The System comprises a dehumidifier and a regenerator with their associated components operating together to dehumidify the fresh (ambient) air supply to a group of offices on the top floor of the building. LiCl-water is employed as the working fluid. The System is coupled to a solar collector field and employs two methods of storage - hot water and Desiccant solution in the regenerated state. The performance of the System was monitored for five summer months under varying operating conditions. The paper describes the operation of the experimental System and presents the measured data and the calculated performance parameters. ?? 2006 Elsevier Ltd. All rights reserved.
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experimental investigation of a liquid Desiccant System for solar cooling and dehumidification
Solar Energy, 2007Co-Authors: Khaled Gommed, Gershon GrossmanAbstract:Abstract Growing demand for air conditioning in recent years has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the environmentally-friendly techniques which may help alleviate the problem. A promising solar cooling method is through the use of a liquid Desiccant System, where humidity is absorbed directly from the process air by direct contact with the Desiccant. The Desiccant is then regenerated, again in direct contact with an external air stream, by solar heat at relatively low temperatures. The liquid Desiccant System has many potential advantages over other solar air conditioning Systems and can provide a promising alternative to absorption or to solid Desiccant Systems. Earlier work by the authors included theoretical simulations and preliminary experiments on the key components of the liquid Desiccant System. The objective of the present study has been to construct a prototype System based on the knowledge gained, to monitor its performance, identify problems and carry out preliminary design optimization. A 16 kWt System was installed at the Energy Engineering Center at the Technion, in the Mediterranean city of Haifa. The System comprises a dehumidifier and a regenerator with their associated components operating together to dehumidify the fresh (ambient) air supply to a group of offices on the top floor of the building. LiCl-water is employed as the working fluid. The System is coupled to a solar collector field and employs two methods of storage – hot water and Desiccant solution in the regenerated state. The performance of the System was monitored for five summer months under varying operating conditions. The paper describes the operation of the experimental System and presents the measured data and the calculated performance parameters.
Jaeweon Jeong - One of the best experts on this subject based on the ideXlab platform.
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Energy Saving Potential of a Thermoelectric Heat Pump-Assisted Liquid Desiccant System in a Dedicated Outdoor Air System
Energies, 2017Co-Authors: Joonyoung Park, Jaeweon JeongAbstract:The main objective of this study was to develop a thermoelectric heat pump and liquid Desiccant System based on a dedicated outdoor air System (THPLD-DOAS). An internally-cooled and -heated liquid Desiccant System was used and a thermoelectric heat pump (THP) served as the Desiccant cooling and heating energy source for dehumidification and regeneration of the Desiccant solution, respectively. In order to investigate the energy-saving potential of the proposed System, its thermal performance and operating energy consumption during the cooling season were compared to those of a conventional dedicated outdoor air System with a ceiling radiant cooling panel System (DOAS-CRCP). Detailed simulations for each System were conducted under hot and humid climatic conditions. Their thermal performance under various room sensible heat factor (RSHF) conditions was evaluated to observe the energy performance, depending on the dehumidification performance, of the liquid Desiccant System integrated with the THP. The results showed that the coefficient of performance (COP) of the THP ranged from 0.8 to 1.2 to maintain a sufficient dehumidification rate. The operating energy of the THPLD of the proposed System was 6.6% to 16.0% less than that of the chiller operating energy of a conventional DOAS. Consequently, the proposed System consumed 0.6–23.5% less operating energy compared to the conventional DOAS.
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simplified model for packed bed tower regenerator in a liquid Desiccant System
Applied Thermal Engineering, 2015Co-Authors: Joonyoung Park, Jaeweon JeongAbstract:Abstract The regeneration rate prediction model representing the regenerator performance in a liquid Desiccant System was derived by statistically analyzing the empirical data collected from the real liquid Desiccant unit operated under various conditions. In order to propose a simple empirical regenerator model with wide valid range, additional experimental data found in open literature were also considered in the model derivation. The lithium chloride (LiCl) solution was used as a working Desiccant solution. Response surface methodology was used to identify operating parameters and their interactions affecting significantly on the regenerator performance in a liquid Desiccant System. Consequently, a first-order linear regression equation was derived as a function of the major parameters and interactions, which returns the regeneration rate in various operating conditions. The reliability of the proposed model was confirmed via the analysis of variation (ANOVA). The proposed model agreed well with the experimental data and other existing models.
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Application of Desiccant Systems for improving the performance of an evaporative cooling-assisted 100% outdoor air System in hot and humid climates
Journal of Building Performance Simulation, 2014Co-Authors: Joonyoung Park, Junseok Park, Jaeweon JeongAbstract:The purpose of this study was to enhance the energy-saving potential of an indirect and direct evaporative cooling-assisted 100% outdoor air System (IDECOAS) by integrating it with either a solid or liquid Desiccant System. The Desiccant System can be installed either at the scavenger air side of the indirect evaporative cooler (IEC) to enhance its effectiveness or at the primary air side of the IEC to reduce the latent load of outdoor air. The operating energy consumption affected by the location and type of the Desiccant unit integrated with IDECOAS was simulated under three different hot and humid climates using TRNSYS 17 integrated with commercial equation solver programme. And then, the most energy-conservative configuration was selected for each climate zone as the proposed System. The simulation results showed that configurations with the Desiccant dehumidification unit located upstream of the IDECOAS consume 76–85% less cooling coil energy than those with the Desiccant unit located downstream of t...
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energy saving potential of liquid Desiccant in evaporative cooling assisted 100 outdoor air System
Energy, 2013Co-Authors: Junseok Park, Jaeweon JeongAbstract:The primary goal of this paper is to suggest integration of a liquid Desiccant System into an evaporative-cooling-assisted 100% outdoor air System. Detailed energy simulation is performed for estimating the impact of the liquid Desiccant System in indirect and direct evaporative cooler operations. The energy saving potential of the proposed System versus a conventional VAV (variable air volume) System is predicted via a series of energy simulations using TRNSYS 16 and a commercial equation solver program. Impact of water-side free cooling and solar thermal System on the operating energy saving of the liquid Desiccant System is quantitatively evaluated. Simulation results showed that the proposed System consumes 51% less cooling energy compared to the conventional VAV System; primarily due to the water-side free cooling in maintaining the absorber temperature of the liquid Desiccant System. The solar water heating System for regenerating the Desiccant solution also contributes to the reduction in operating energy.
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Energy saving potential of liquid Desiccant in evaporative-cooling-assisted 100% outdoor air System
Energy, 2013Co-Authors: Junseok Park, Jaeweon JeongAbstract:The primary goal of this paper is to suggest integration of a liquid Desiccant System into an evaporative-cooling-assisted 100% outdoor air System. Detailed energy simulation is performed for estimating the impact of the liquid Desiccant System in indirect and direct evaporative cooler operations. The energy saving potential of the proposed System versus a conventional VAV (variable air volume) System is predicted via a series of energy simulations using TRNSYS 16 and a commercial equation solver program. Impact of water-side free cooling and solar thermal System on the operating energy saving of the liquid Desiccant System is quantitatively evaluated. Simulation results showed that the proposed System consumes 51% less cooling energy compared to the conventional VAV System; primarily due to the water-side free cooling in maintaining the absorber temperature of the liquid Desiccant System. The solar water heating System for regenerating the Desiccant solution also contributes to the reduction in operating energy.
Khaled Gommed - One of the best experts on this subject based on the ideXlab platform.
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Hybrid liquid Desiccant System design and operation under high latent load conditions in Taiwan
International Journal of Refrigeration-revue Internationale Du Froid, 2019Co-Authors: Xabier Peña, Juan Prieto, Laura Alonso, Andoni Diaz De Mendibil, Khaled GommedAbstract:Abstract Hybrid Liquid Desiccant Systems (HLDS) combine the liquid Desiccant technology for dehumidification of air with conventional compression cycle technology for cooling. They are an alternative to conventional compression cooling Systems, being more efficient and offering the possibility of independently control temperature and humidity. In this paper the design and operation of a HLDS is presented, for the air conditioning of a high latent load application with high ambient humidity levels. An analysis of the daily evolution of the performance of the System under different environmental conditions has been included. The innovative demonstration unit placed in Taiwan, in continuous operation since November 2015, achieved Energy efficiency Ratios (EER) up to 4.6.
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Experimental comparison between internally and externally cooled air-solution contactors
Science and Technology for the Built Environment, 2015Co-Authors: Khaled Gommed, Gershon Grossman, Juan Prieto, Jordi Ortiga, Alberto CoronasAbstract:Air-conditioning demand, especially in hot and humid climates, causes most of the energy consumption in buildings. In these applications, the latent load often constitutes a significant part of the total load. Conventional air-conditioning Systems deal with the required dehumidification by cooling the moist air below its dew point and reheat it later to increase its temperature to comfortable supply conditions. By using solid/liquid Desiccant Systems, which absorb humidity from the air, it becomes unnecessary to reach the dew point to dehumidify, thereby reducing energy consumption. In liquid Desiccant Systems, dehumidification occurs in the absorber, where the humidity of the air is absorbed by direct contact with a Desiccant. Most of the previous liquid Desiccant System studies have used adiabatic absorbers, where the solution must be cooled externally before being delivered into the air-solution contactor. However, based on experience with closed-cycle absorption Systems, internally cooled absorbers ar...
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Investigation of an improved solar-powered open absorption System for cooling, dehumidification and air conditioning
International Journal of Refrigeration, 2012Co-Authors: Khaled Gommed, Gershon GrossmanAbstract:This study is concerned with an open absorption (liquid Desiccant) System, capable of producing both cooling and dehumidification for air conditioning, utilizing low-grade heat. The System includes a novel solution heat and mass exchanger (HME) designed to serve as a Desiccant solution reservoir for both the absorber and desorber, enabling mass transfer between them with minimum heat transfer losses and eliminating the need for an external recuperative heat exchanger. The use of this new HME together with an improved solution flow arrangement in the new System facilitates the use of adiabatic absorption/desorption with minimum circulation heat losses and wetting problems. The characteristic performance of the System was studied under varying operating conditions. The use of the new HME has fulfilled the objective of reducing the time constant of the System, helped correct idling and level control problems and ensures maximum solution concentration on the absorber side during desorber operation. ?? 2012 Elsevier Ltd and IIR. All rights reserved.
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Experimental investigation of a liquid Desiccant System for solar cooling and dehumidification
Solar Energy, 2007Co-Authors: Khaled Gommed, Gershon GrossmanAbstract:Growing demand for air conditioning in recent years has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the environmentally-friendly techniques which may help alleviate the problem. A promising solar cooling method is through the use of a liquid Desiccant System, where humidity is absorbed directly from the process air by direct contact with the Desiccant. The Desiccant is then regenerated, again in direct contact with an external air stream, by solar heat at relatively low temperatures. The liquid Desiccant System has many potential advantages over other solar air conditioning Systems and can provide a promising alternative to absorption or to solid Desiccant Systems. Earlier work by the authors included theoretical simulations and preliminary experiments on the key components of the liquid Desiccant System. The objective of the present study has been to construct a prototype System based on the knowledge gained, to monitor its performance, identify problems and carry out preliminary design optimization. A 16 kWt System was installed at the Energy Engineering Center at the Technion, in the Mediterranean city of Haifa. The System comprises a dehumidifier and a regenerator with their associated components operating together to dehumidify the fresh (ambient) air supply to a group of offices on the top floor of the building. LiCl-water is employed as the working fluid. The System is coupled to a solar collector field and employs two methods of storage - hot water and Desiccant solution in the regenerated state. The performance of the System was monitored for five summer months under varying operating conditions. The paper describes the operation of the experimental System and presents the measured data and the calculated performance parameters. ?? 2006 Elsevier Ltd. All rights reserved.
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experimental investigation of a liquid Desiccant System for solar cooling and dehumidification
Solar Energy, 2007Co-Authors: Khaled Gommed, Gershon GrossmanAbstract:Abstract Growing demand for air conditioning in recent years has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the environmentally-friendly techniques which may help alleviate the problem. A promising solar cooling method is through the use of a liquid Desiccant System, where humidity is absorbed directly from the process air by direct contact with the Desiccant. The Desiccant is then regenerated, again in direct contact with an external air stream, by solar heat at relatively low temperatures. The liquid Desiccant System has many potential advantages over other solar air conditioning Systems and can provide a promising alternative to absorption or to solid Desiccant Systems. Earlier work by the authors included theoretical simulations and preliminary experiments on the key components of the liquid Desiccant System. The objective of the present study has been to construct a prototype System based on the knowledge gained, to monitor its performance, identify problems and carry out preliminary design optimization. A 16 kWt System was installed at the Energy Engineering Center at the Technion, in the Mediterranean city of Haifa. The System comprises a dehumidifier and a regenerator with their associated components operating together to dehumidify the fresh (ambient) air supply to a group of offices on the top floor of the building. LiCl-water is employed as the working fluid. The System is coupled to a solar collector field and employs two methods of storage – hot water and Desiccant solution in the regenerated state. The performance of the System was monitored for five summer months under varying operating conditions. The paper describes the operation of the experimental System and presents the measured data and the calculated performance parameters.
Wanjun Qu - One of the best experts on this subject based on the ideXlab platform.
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a new hybrid photovoltaic thermal and liquid Desiccant System for trigeneration application
Applied Energy, 2018Co-Authors: Bosheng Su, Wanjun QuAbstract:Abstract Conventional combined cooling, heating and power (CCHP) Systems based on fossil fuels, with an acceptable energy performance, however, intensify the greenhouse effect worldwide. Using solar energy in distributed energy Systems has the potential to further reduce fossil fuels consumption, and ease carbon emissions. This paper proposes a novel CCHP System by combining concentrated photovoltaic/thermal (PV/T) technology with an advanced air-handling process that realizes independent control of temperature and humidity. The heat produced from a PV/T collector is for Desiccant regeneration in a two-stage liquid Desiccant cycle in summer, and can be directly supplied to nearby users in winter. An office building under typical climate conditions of Beijing in 2002 was adopted to determine its various energy demands. Due to the efficient use of solar energy, annual energy saving ratio and CO2 emissions reduction ratio are predicted to be 73.28% and 74.55%, respectively. Two extreme conditions determining whether the excess heat from the PV/T collector is used were compared to demonstrate the top and bottom limitations of economic performance. The integrated performance, considering energy, environment and economic factors, reaches 37.48% when no excess heat from PV/T collector is used, and it can be further improved by thermal storage or recovering the excess heat to produce other products. This study provides a new solar utilization technology for trigeneration with advanced integrated performance.
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Performance analysis of a hybrid photovoltaic/thermal and liquid Desiccant System
Energy Procedia, 2018Co-Authors: Bosheng Su, Wanjun QuAbstract:Abstract Air dehumidification is widely applied in the civilian and industrial use, however, conventional vapor compression air-conditioning System consumes substantial power. Using renewable energy in the air handling process has potential to further reduce the power consumption, meanwhile ease the carbon emission. This paper proposes a novel liquid Desiccant System integrated with a photovoltaic/thermal collector for deep dehumidification. The generated electric power drives a vapor compression chiller for cooling the Desiccant solution for a two-stage dehumidification, and the releasing heat from the collector is used for the Desiccant regeneration. Simulation studies indicated the proposed System has a superior power saving ability of 55.65% comparing with the conventional one, besides the equivalent power generation efficiency reaches 8.7%.
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feasibility of a hybrid photovoltaic thermal and liquid Desiccant System for deep dehumidification
Energy Conversion and Management, 2018Co-Authors: Bosheng Su, Wanjun QuAbstract:Abstract Air dehumidification is widely applied in the civilian and industrial use, however, conventional vapor compression air-conditioning System consumes substantial power. Using renewable energy in the air handling process has potential to further reduce the power consumption, meanwhile ease the carbon emission. This paper proposes a novel liquid Desiccant System integrated with a concentrated photovoltaic/thermal collector for deep dehumidification. The generated electric power drives a vapor compression chiller for cooling the Desiccant solution for a two-stage dehumidification, and the released heat from the collector is used for the Desiccant regeneration. Simulation studies indicated the proposed System has a superior power saving ability of 55.65% comparing with the conventional one, besides the equivalent power generation efficiency reaches 8.7% in the base design condition. A comparative driven force analysis showed the two-stage dehumidification has a better match of driven force compared with the single-stage liquid Desiccant dehumidification, thus leading to a reduced irreversible loss of 65.43%. Sensitivity analysis indicated that the dehumidification temperature has a decisive effect on the System performance. The exergy efficiency has a maximum value of 13% as the dehumidification temperature is 22.3 °C. The economic studies showed that the investment on the concentrated photovoltaic/thermal collector account for the largest share of the total initial investment, and has a significant effect on the payback period. The payback period would be reduced further if the benefit of the clean development mechanism (CDM) is considered.
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Feasibility of a hybrid photovoltaic/thermal and liquid Desiccant System for deep dehumidification
Energy Conversion and Management, 2018Co-Authors: Bosheng Su, Wanjun QuAbstract:Abstract Air dehumidification is widely applied in the civilian and industrial use, however, conventional vapor compression air-conditioning System consumes substantial power. Using renewable energy in the air handling process has potential to further reduce the power consumption, meanwhile ease the carbon emission. This paper proposes a novel liquid Desiccant System integrated with a concentrated photovoltaic/thermal collector for deep dehumidification. The generated electric power drives a vapor compression chiller for cooling the Desiccant solution for a two-stage dehumidification, and the released heat from the collector is used for the Desiccant regeneration. Simulation studies indicated the proposed System has a superior power saving ability of 55.65% comparing with the conventional one, besides the equivalent power generation efficiency reaches 8.7% in the base design condition. A comparative driven force analysis showed the two-stage dehumidification has a better match of driven force compared with the single-stage liquid Desiccant dehumidification, thus leading to a reduced irreversible loss of 65.43%. Sensitivity analysis indicated that the dehumidification temperature has a decisive effect on the System performance. The exergy efficiency has a maximum value of 13% as the dehumidification temperature is 22.3 °C. The economic studies showed that the investment on the concentrated photovoltaic/thermal collector account for the largest share of the total initial investment, and has a significant effect on the payback period. The payback period would be reduced further if the benefit of the clean development mechanism (CDM) is considered.
Joonyoung Park - One of the best experts on this subject based on the ideXlab platform.
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Energy Saving Potential of a Thermoelectric Heat Pump-Assisted Liquid Desiccant System in a Dedicated Outdoor Air System
Energies, 2017Co-Authors: Joonyoung Park, Jaeweon JeongAbstract:The main objective of this study was to develop a thermoelectric heat pump and liquid Desiccant System based on a dedicated outdoor air System (THPLD-DOAS). An internally-cooled and -heated liquid Desiccant System was used and a thermoelectric heat pump (THP) served as the Desiccant cooling and heating energy source for dehumidification and regeneration of the Desiccant solution, respectively. In order to investigate the energy-saving potential of the proposed System, its thermal performance and operating energy consumption during the cooling season were compared to those of a conventional dedicated outdoor air System with a ceiling radiant cooling panel System (DOAS-CRCP). Detailed simulations for each System were conducted under hot and humid climatic conditions. Their thermal performance under various room sensible heat factor (RSHF) conditions was evaluated to observe the energy performance, depending on the dehumidification performance, of the liquid Desiccant System integrated with the THP. The results showed that the coefficient of performance (COP) of the THP ranged from 0.8 to 1.2 to maintain a sufficient dehumidification rate. The operating energy of the THPLD of the proposed System was 6.6% to 16.0% less than that of the chiller operating energy of a conventional DOAS. Consequently, the proposed System consumed 0.6–23.5% less operating energy compared to the conventional DOAS.
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simplified model for packed bed tower regenerator in a liquid Desiccant System
Applied Thermal Engineering, 2015Co-Authors: Joonyoung Park, Jaeweon JeongAbstract:Abstract The regeneration rate prediction model representing the regenerator performance in a liquid Desiccant System was derived by statistically analyzing the empirical data collected from the real liquid Desiccant unit operated under various conditions. In order to propose a simple empirical regenerator model with wide valid range, additional experimental data found in open literature were also considered in the model derivation. The lithium chloride (LiCl) solution was used as a working Desiccant solution. Response surface methodology was used to identify operating parameters and their interactions affecting significantly on the regenerator performance in a liquid Desiccant System. Consequently, a first-order linear regression equation was derived as a function of the major parameters and interactions, which returns the regeneration rate in various operating conditions. The reliability of the proposed model was confirmed via the analysis of variation (ANOVA). The proposed model agreed well with the experimental data and other existing models.
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Application of Desiccant Systems for improving the performance of an evaporative cooling-assisted 100% outdoor air System in hot and humid climates
Journal of Building Performance Simulation, 2014Co-Authors: Joonyoung Park, Junseok Park, Jaeweon JeongAbstract:The purpose of this study was to enhance the energy-saving potential of an indirect and direct evaporative cooling-assisted 100% outdoor air System (IDECOAS) by integrating it with either a solid or liquid Desiccant System. The Desiccant System can be installed either at the scavenger air side of the indirect evaporative cooler (IEC) to enhance its effectiveness or at the primary air side of the IEC to reduce the latent load of outdoor air. The operating energy consumption affected by the location and type of the Desiccant unit integrated with IDECOAS was simulated under three different hot and humid climates using TRNSYS 17 integrated with commercial equation solver programme. And then, the most energy-conservative configuration was selected for each climate zone as the proposed System. The simulation results showed that configurations with the Desiccant dehumidification unit located upstream of the IDECOAS consume 76–85% less cooling coil energy than those with the Desiccant unit located downstream of t...
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A simplified model for predicting dehumidification effectiveness of a liquid Desiccant System
AEI 2013, 2013Co-Authors: Joonyoung Park, Jaeweon JeongAbstract:The main purpose of this research is to propose a practical correlation returning the dehumidification effectiveness of a liquid Desiccant System. From the existing literature, it was found that two Desiccant solutions; lithium chloride(LiCl), and triethylene glycol (TEG) solutions are commonly used as a working fluid in two different types of absorber towers; packed bed, and spray towers. In this research, the experimental data of each absorber tower performance with two different Desiccant solutions were collected from the open literature. By statistically analyzing the collected data using the 2 k factorial experiment design approach, the impact of each System operation parameters on the dehumidification effectiveness were quantitatively estimated. And then, a simplified second-order equation model was derived as a function of operation parameters showing significant impact on the dehumidification effectiveness. It was found that the operating parameters, such as inlet ambient air temperature, Desiccant solution temperature, liquidto-gas ratio(L/G), inlet air relative humidity, and solution concentration have significant impact on the System dehumidification performance. The proposed model was validated by comparing the dehumidification effectiveness values predicted by both proposed model and existing models found in the existing literature.