The Experts below are selected from a list of 26415 Experts worldwide ranked by ideXlab platform
Jinping Liu - One of the best experts on this subject based on the ideXlab platform.
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Performance analysis of solar air cooled double effect LiBr/H2O Absorption Cooling system in subtropical city
Energy Conversion and Management, 2014Co-Authors: Jinping LiuAbstract:Due to the absence of Cooling tower and independent on water, the air cooled solar double effect LiBr/H2O Absorption Cooling system is more convenient to be used in commercial building and household use. The performance with collector temperature is an important field for such system. The paper mainly deals with the performance with collector temperature for the solar air cooled double effect LiBr/H2O Absorption Cooling system in subtropical city. The parameters of system are: aperture area of collector array is 27 m2, tilted angle of collector with respect to the horizontal plane is 20 toward to south evaporator temperature is 5 °C and the Cooling capacity is 20 kW. The simulation is based on the meteorological data of monthly typical day which was summarized from a year round measured data. A corresponding parametric model was developed. The hourly and average performance with the collector temperature for monthly typical day was obtained and discussed. It was found that the suitable working range of inlet temperature of collector is 110–130 °C to improve performance and lower the risk of crystallization. The difference of hourly total efficiency in 9:00–16:00 is less, and the monthly total efficiency from May to October is approximate. The yearly performance of system including total efficiency, Cooling capacity per area of collector and solar fraction was given. Furthermore, the effect of effectiveness of heat exchanger and pressure drop on total efficiency and solar fraction was studied and compared. The paper can serve as a preliminary investigation of solar air cooled double effect LiBr/H2O Absorption Cooling system in subtropical city, and provides the foundation of further study.
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performance analysis of solar air cooled double effect libr h2o Absorption Cooling system in subtropical city
Energy Conversion and Management, 2014Co-Authors: Jinping LiuAbstract:Due to the absence of Cooling tower and independent on water, the air cooled solar double effect LiBr/H2O Absorption Cooling system is more convenient to be used in commercial building and household use. The performance with collector temperature is an important field for such system. The paper mainly deals with the performance with collector temperature for the solar air cooled double effect LiBr/H2O Absorption Cooling system in subtropical city. The parameters of system are: aperture area of collector array is 27 m2, tilted angle of collector with respect to the horizontal plane is 20 toward to south evaporator temperature is 5 °C and the Cooling capacity is 20 kW. The simulation is based on the meteorological data of monthly typical day which was summarized from a year round measured data. A corresponding parametric model was developed. The hourly and average performance with the collector temperature for monthly typical day was obtained and discussed. It was found that the suitable working range of inlet temperature of collector is 110–130 °C to improve performance and lower the risk of crystallization. The difference of hourly total efficiency in 9:00–16:00 is less, and the monthly total efficiency from May to October is approximate. The yearly performance of system including total efficiency, Cooling capacity per area of collector and solar fraction was given. Furthermore, the effect of effectiveness of heat exchanger and pressure drop on total efficiency and solar fraction was studied and compared. The paper can serve as a preliminary investigation of solar air cooled double effect LiBr/H2O Absorption Cooling system in subtropical city, and provides the foundation of further study.
Paul Henshaw - One of the best experts on this subject based on the ideXlab platform.
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residential solar air conditioning energy and exergy analyses of an ammonia water Absorption Cooling system
Applied Thermal Engineering, 2014Co-Authors: Julia Aman, David S K Ting, Paul HenshawAbstract:Large scale heat-driven Absorption Cooling systems are available in the marketplace for industrial applications but the concept of a solar driven Absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the Absorption Cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammoniaewater Absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammoniaewater Absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale Cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature.
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Residential solar air conditioning: Energy and exergy analyses of an ammonia–water Absorption Cooling system
Applied Thermal Engineering, 2014Co-Authors: Julia Aman, David S K Ting, Paul HenshawAbstract:Large scale heat-driven Absorption Cooling systems are available in the marketplace for industrial applications but the concept of a solar driven Absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the Absorption Cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammoniaewater Absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammoniaewater Absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale Cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature.
Julia Aman - One of the best experts on this subject based on the ideXlab platform.
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residential solar air conditioning energy and exergy analyses of an ammonia water Absorption Cooling system
Applied Thermal Engineering, 2014Co-Authors: Julia Aman, David S K Ting, Paul HenshawAbstract:Large scale heat-driven Absorption Cooling systems are available in the marketplace for industrial applications but the concept of a solar driven Absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the Absorption Cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammoniaewater Absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammoniaewater Absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale Cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature.
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Residential solar air conditioning: Energy and exergy analyses of an ammonia–water Absorption Cooling system
Applied Thermal Engineering, 2014Co-Authors: Julia Aman, David S K Ting, Paul HenshawAbstract:Large scale heat-driven Absorption Cooling systems are available in the marketplace for industrial applications but the concept of a solar driven Absorption chiller for air-conditioning applications is relatively new. Absorption chillers have a lower efficiency than compression refrigeration systems, when used for small scale applications and this restrains the Absorption Cooling system from air conditioning applications in residential buildings. The potential of a solar driven ammoniaewater Absorption chiller for residential air conditioning application is discussed and analyzed in this paper. A thermodynamic model has been developed based on a 10 kW air cooled ammoniaewater Absorption chiller driven by solar thermal energy. Both energy and exergy analyses have been conducted to evaluate the performance of this residential scale Cooling system. The analyses uncovered that the absorber is where the most exergy loss occurs (63%) followed by the generator (13%) and the condenser (11%). Furthermore, the exergy loss of the condenser and absorber greatly increase with temperature, the generator less so, and the exergy loss in the evaporator is the least sensitive to increasing temperature.
Abdulvahap Yigit - One of the best experts on this subject based on the ideXlab platform.
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simulation of solar powered Absorption Cooling system
Renewable Energy, 2003Co-Authors: Ibrahim Atmaca, Abdulvahap YigitAbstract:With developing technology and the rapid increase in world population, the demand for energy is ever increasing. Conventional energy will not be enough to meet the continuously increasing need for energy in the future. In this case, renewable energy sources will become important. Solar energy is a very important energy source because of its advantages. Instead of a compressor system, which uses electricity, an Absorption Cooling system, using renewable energy and kinds of waste heat energy, may be used for Cooling. In this study, a solar-powered, single stage, Absorption Cooling system, using a water–lithium bromide solution, is simulated. A modular computer program has been developed for the Absorption system to simulate various cycle configurations and solar energy parameters for Antalya, Turkey. So, the effects of hot water inlet temperatures on the coefficient of performance (COP) and the surface area of the Absorption Cooling components are studied. In addition, reference temperatures which are the minimum allowable hot water inlet temperatures are determined and their effect on the fraction of the total load met by non–purchased energy (FNP) and the coefficient of performance are researched. Also, the effects of the collector type and storage tank mass are investigated in detail.
Dieter Boer - One of the best experts on this subject based on the ideXlab platform.
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A systematic tool for the minimization of the life cycle impact of solar assisted Absorption Cooling systems
Energy, 2010Co-Authors: Berhane H. Gebreslassie, Gonzalo Guillén-gosálbez, Laureano Jiménez, Dieter BoerAbstract:In recent years, there has been a growing increase of the Cooling demand in many parts of the world, which has led to major energy problems. In this context, solar assisted Absorption Cooling systems have emerged as a promising alternative to conventional vapor compression air conditioning systems, given the fact that in many cases the Cooling demand coincide with the availability of solar radiation. In this work, we present a decision-support tool based on mathematical programming for the design of solar assisted Absorption Cooling systems. The design task is formulated as a bi-criteria mixed-integer nonlinear programming (MINLP) optimization problem that accounts for the minimization of the total cost of the Cooling system and the associated environmental impact measured over its entire life cycle. The capabilities of the proposed method are illustrated in a case study that addresses the design of a solar assisted ammonia-water Absorption cycle considering weather data of Barcelona (Spain).
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Multi-objective optimization of solar assisted Absorption Cooling system
Computer-aided chemical engineering, 2010Co-Authors: Berhane H. Gebreslassie, Melanie Jimenez, Gonzalo Guillén-gosálbez, Laureano Jiménez, Dieter BoerAbstract:This work presents a multi-period and multi-objective optimization based on mathematical programming of solar assisted Absorption Cooling systems. Seven solar collector models combined with a gas fired heater and an Absorption Cooling cycle are considered. The optimization task is formulated as a multi-objective multi-period mixed-integer nonlinear programming (MINLP) problem that accounts for the minimization of the total cost of the Cooling system and the associated environmental impact. The environmental performance is measured following the Life Cycle Assessment (LCA) principles. The capabilities of the proposed method are illustrated in a case study that addresses the design of a solar assisted ammonia-water Absorption Cooling system using the weather conditions of Tarragona (Spain).
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Economic performance optimization of an Absorption Cooling system under uncertainty
Applied Thermal Engineering, 2009Co-Authors: Berhane H. Gebreslassie, Gonzalo Guillén-gosálbez, Laureano Jiménez, Dieter BoerAbstract:Many of the strategies devised so far to address the optimization of energy systems are deterministic approaches that rely on estimated data. However, in real world applications there are many sources of uncertainty that introduce variability into the decision-making problem. Within this general context, we propose a novel approach to address the design of Absorption Cooling systems under uncertainty in the energy cost. As opposed to other approaches that optimize the expected performance of the system as a single objective, in our method the design task is formulated as a stochastic bi-criteria non-linear optimization problem that simultaneously accounts for the minimization of the expected total cost and the financial risk associated with the investment. The latter criterion is measured by the downside risk, which avoids the need to define binary variables thus improving the computational performance of the model. The capabilities of the proposed modeling framework and solution strategy are illustrated in a case study problem that addresses the design of a typical Absorption Cooling system. Numerical results demonstrate that the method presented allows to manage the risk level effectively by varying the area of the heat exchangers of the Absorption cycle. Specifically, our strategy allows identifying the optimal values of the operating and design variables of the cycle that make it less sensitive to fluctuations in the energy price, thus improving its robustness in the face of uncertainty.
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Design of environmentally conscious Absorption Cooling systems via multi-objective optimization and life cycle assessment
Applied Energy, 2009Co-Authors: Berhane H. Gebreslassie, Gonzalo Guillén-gosálbez, Laureano Jiménez, Dieter BoerAbstract:In this paper, a systematic method based on mathematical programming is proposed for the design of environmentally conscious Absorption Cooling systems. The approach presented relies on the development of a multi-objective formulation that simultaneously accounts for the minimization of cost and environmental impact at the design stage. The latter criterion is measured by the Eco-indicator 99 methodology, which follows the principles of life cycle assessment (LCA). The design task is formulated as a bi-criteria nonlinear programming (NLP) problem, the solution of which is defined by a set of Pareto points that represent the optimal trade-off between the economic and environmental concerns considered in the analysis. These Pareto solutions can be obtained via standard techniques for multi-objective optimization. The main advantage of this approach is that it offers a set of alternative options for system design rather than a single solution. From these alternatives, the decision-maker can choose the best one according to his/her preferences and the applicable legislation. The capabilities of the proposed method are illustrated in a case study problem that addresses the design of a typical Absorption Cooling system.
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Economic performance optimization of an Absorption Cooling system under uncertainty
Applied Thermal Engineering, 2009Co-Authors: Berhane H. Gebreslassie, Gonzalo Guillén-gosálbez, Laureano Jiménez, Dieter BoerAbstract:International audienceMany of the strategies devised so far to address the optimization of energy systems are deterministic approaches that rely on estimated data. However, in real world applications there are many sources of uncertainty that introduce variability into the decision-making problem. Within this general context, we propose a novel approach to address the design of Absorption Cooling systems under uncertainty in the energy cost. As opposed to other approaches that optimize the expected performance of the system as a single objective, in our method the design task is formulated as a stochastic bi-criteria non-linear optimization problem that simultaneously accounts for the minimization of the expected total cost and the financial risk associated with the investment. The latter criterion is measured by the downside risk, which avoids the need to define binary variables thus improving the computational performance of the model. The capabilities of the proposed modeling framework and solution strategy are illustrated in a case study problem that addresses the design of a typical Absorption Cooling system. Numerical results demonstrate that the method presented allows to manage the risk level effectively by varying the area of the heat exchangers of the Absorption cycle. Specifically, our strategy allows identifying the optimal values of the operating and design variables of the cycle that make it less sensitive to fluctuations in the energy price, thus improving its robustness in the face of uncertainty
