The Experts below are selected from a list of 92814 Experts worldwide ranked by ideXlab platform
Ala Hasan - One of the best experts on this subject based on the ideXlab platform.
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going below the wet bulb Temperature by indirect evaporative cooling analysis using a modified e ntu method
Applied Energy, 2012Co-Authors: Ala HasanAbstract:The objective of this paper is to study a method to achieve sub-wet bulb Temperature by indirect evaporative cooling of air (without using a vapor compression machine). For this purpose, an analytical model is developed based on the effectiveness-NTU method (e-NTU). The main idea for achieving a sub-wet bulb Temperature by indirect evaporative cooling of air is by indirectly pre-cooling the working air before it enters the wet passage. It is shown that a modified analytical model for indirect evaporative coolers could be based on the e-NTU method for sensible heat exchangers when proper adjustments are made by redefining the potential gradients, transfer coefficient, heat capacity rate parameters and assuming a linear saturation Temperature-enthalpy relation of air. This modified model is used to find the performance of a regenerative indirect evaporative cooler. The model results show very good agreement with results from experimental measurements and a numerical model.
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indirect evaporative cooling of air to a sub wet bulb Temperature
Applied Thermal Engineering, 2010Co-Authors: Ala HasanAbstract:Abstract Indirect evaporative cooling is a sustainable method for cooling of air. The main constraint that limits the wide use of evaporative coolers is the ultimate Temperature of the process, which is the wet bulb Temperature of ambient air. In this paper, a method is presented to produce air at a sub-wet bulb Temperature by indirect evaporative cooling, without using a vapour compression machine. The main idea consists of manipulating the air flow inside the cooler by branching the working air from the product air, which is indirectly pre-cooled, before it is finally cooled and delivered. A model for the heat and mass transfer process is developed. Four types of coolers are studied: three two-stage coolers (a counter flow, a parallel flow and a combined parallel-regenerative flow) and a single-stage counter flow regenerative cooler. It is concluded that the proposed method for indirect evaporative cooling is capable of cooling air to Temperatures lower than the ambient wet bulb Temperature. The ultimate Temperature for such a process is the dew point Temperature of the ambient air. The wet bulb cooling effectiveness ( E wb ) for the examples studied is 1.26, 1.09 and 1.31 for the two-stage counter flow, parallel flow and combined parallel-regenerative cooler, respectively, and it is 1.16 for the single-stage counter flow regenerative cooler. Such a method extends the potential of useful utilisation of evaporative coolers for cooling of buildings as well as other industrial applications.
Rabah Boukhanouf - One of the best experts on this subject based on the ideXlab platform.
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computer modelling and experimental investigation of building integrated sub wet bulb Temperature evaporative cooling system
Applied Thermal Engineering, 2017Co-Authors: Rabah Boukhanouf, Hatem Ibrahim, Abdulrahman Alharbi, Omar Amer, Mark WorallAbstract:The paper presents computer modelling and laboratory experiment results of a sub-wet bulb Temperature indirect evaporative cooling system for space cooling in buildings. The prototype employs hollow porous ceramic water containers as wet media material for water evaporation. The cooled air is delivered without increasing its moisture content. The performance of the cooler was evaluated using a computer model, and the results of which were validated experimentally. The cooling capacity and effectiveness of the cooler were evaluated at inlet air dry bulb Temperature of 30 and 35°C and relative humidity ranging from 35% to 50%. It was found that the cooler can supply air for space cooling at sub-wet bulb Temperature conditions; achieve measured cooling capacity approaching 225 W/m2 of exposed ceramic material wet surface area and wet bulb effectiveness higher than unity. The high thermal performance of the constructed evaporative cooler indicates the system could be a potential substitute to conventional mechanical air-conditioning systems in buildings in many parts of the world where hot and dry climatic conditions prevail.
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mathematical modeling of a sub wet bulb Temperature evaporative cooling using porous ceramic materials
World Academy of Science Engineering and Technology International Journal of Industrial and Manufacturing Engineering, 2013Co-Authors: Meryem Kanzari, Rabah Boukhanouf, Hatem IbrahimAbstract:Indirect Evaporative Cooling process has the advantage of supplying cool air at constant mo However, such system can only supply air at Temperatures above wet bulb Temperature. This paper presents a mathematical model for a Sub-wet bulb Temperature indirect evaporative cooling arrangement that can overcome this limitation and supply cool air at Temperatures approaching dew point and without increasing its moisture content. In addition, the use of porous ceramics as wet media materials offers the advantage of integration into building elements. Results of the computer show the proposed design is capable of cooling air to Temperatures lower than the ambient wet bulb Temperature and achieving wet bulb effectiveness of about 1.17. Keywords—Indirect evaporative cooling, porous ceramic, sub wet bulb Temperature.
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investigation of a sub wet bulb Temperature evaporative cooler for buildings
2013Co-Authors: Rabah Boukhanouf, Abdulrahman Alharbi, Hatem IbrahimAbstract:The paper presents a computer model and experimental results of an indirect evaporative cooling system for air conditioning in hot and dry climate regions. The system uses porous/fired clay materials as wet media for water evaporation. The supply air and working air flows were staged in separate ducts and in counter flow direction. Modelling results were conducted for ambient air dry bulb Temperature ranging from 30 o C to 45 o C and relative humidity lower than 65%, showing that supply air would be cooled to below wet bulb Temperature. In addition, it was estimated that the indirect evaporative cooler would achieve cooling capacity of approximately 27 W/m 2 of exposed ceramic material wet area and with overall wet bulb effectiveness greater than unity. This performance would make the system a potential alternative to conventional mechanical air conditioning systems in buildings.
Hatem Ibrahim - One of the best experts on this subject based on the ideXlab platform.
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computer modelling and experimental investigation of building integrated sub wet bulb Temperature evaporative cooling system
Applied Thermal Engineering, 2017Co-Authors: Rabah Boukhanouf, Hatem Ibrahim, Abdulrahman Alharbi, Omar Amer, Mark WorallAbstract:The paper presents computer modelling and laboratory experiment results of a sub-wet bulb Temperature indirect evaporative cooling system for space cooling in buildings. The prototype employs hollow porous ceramic water containers as wet media material for water evaporation. The cooled air is delivered without increasing its moisture content. The performance of the cooler was evaluated using a computer model, and the results of which were validated experimentally. The cooling capacity and effectiveness of the cooler were evaluated at inlet air dry bulb Temperature of 30 and 35°C and relative humidity ranging from 35% to 50%. It was found that the cooler can supply air for space cooling at sub-wet bulb Temperature conditions; achieve measured cooling capacity approaching 225 W/m2 of exposed ceramic material wet surface area and wet bulb effectiveness higher than unity. The high thermal performance of the constructed evaporative cooler indicates the system could be a potential substitute to conventional mechanical air-conditioning systems in buildings in many parts of the world where hot and dry climatic conditions prevail.
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mathematical modeling of a sub wet bulb Temperature evaporative cooling using porous ceramic materials
World Academy of Science Engineering and Technology International Journal of Industrial and Manufacturing Engineering, 2013Co-Authors: Meryem Kanzari, Rabah Boukhanouf, Hatem IbrahimAbstract:Indirect Evaporative Cooling process has the advantage of supplying cool air at constant mo However, such system can only supply air at Temperatures above wet bulb Temperature. This paper presents a mathematical model for a Sub-wet bulb Temperature indirect evaporative cooling arrangement that can overcome this limitation and supply cool air at Temperatures approaching dew point and without increasing its moisture content. In addition, the use of porous ceramics as wet media materials offers the advantage of integration into building elements. Results of the computer show the proposed design is capable of cooling air to Temperatures lower than the ambient wet bulb Temperature and achieving wet bulb effectiveness of about 1.17. Keywords—Indirect evaporative cooling, porous ceramic, sub wet bulb Temperature.
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investigation of a sub wet bulb Temperature evaporative cooler for buildings
2013Co-Authors: Rabah Boukhanouf, Abdulrahman Alharbi, Hatem IbrahimAbstract:The paper presents a computer model and experimental results of an indirect evaporative cooling system for air conditioning in hot and dry climate regions. The system uses porous/fired clay materials as wet media for water evaporation. The supply air and working air flows were staged in separate ducts and in counter flow direction. Modelling results were conducted for ambient air dry bulb Temperature ranging from 30 o C to 45 o C and relative humidity lower than 65%, showing that supply air would be cooled to below wet bulb Temperature. In addition, it was estimated that the indirect evaporative cooler would achieve cooling capacity of approximately 27 W/m 2 of exposed ceramic material wet area and with overall wet bulb effectiveness greater than unity. This performance would make the system a potential alternative to conventional mechanical air conditioning systems in buildings.
Mark Worall - One of the best experts on this subject based on the ideXlab platform.
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computer modelling and experimental investigation of building integrated sub wet bulb Temperature evaporative cooling system
Applied Thermal Engineering, 2017Co-Authors: Rabah Boukhanouf, Hatem Ibrahim, Abdulrahman Alharbi, Omar Amer, Mark WorallAbstract:The paper presents computer modelling and laboratory experiment results of a sub-wet bulb Temperature indirect evaporative cooling system for space cooling in buildings. The prototype employs hollow porous ceramic water containers as wet media material for water evaporation. The cooled air is delivered without increasing its moisture content. The performance of the cooler was evaluated using a computer model, and the results of which were validated experimentally. The cooling capacity and effectiveness of the cooler were evaluated at inlet air dry bulb Temperature of 30 and 35°C and relative humidity ranging from 35% to 50%. It was found that the cooler can supply air for space cooling at sub-wet bulb Temperature conditions; achieve measured cooling capacity approaching 225 W/m2 of exposed ceramic material wet surface area and wet bulb effectiveness higher than unity. The high thermal performance of the constructed evaporative cooler indicates the system could be a potential substitute to conventional mechanical air-conditioning systems in buildings in many parts of the world where hot and dry climatic conditions prevail.
Guo Yue Niu - One of the best experts on this subject based on the ideXlab platform.
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a wet bulb Temperature based rain snow partitioning scheme improves snowpack prediction over the drier western united states
Geophysical Research Letters, 2019Co-Authors: Yuan Heng Wang, P D Broxton, Yuanhao Fang, Ali Behrangi, Michael Barlage, Xubin Zeng, Guo Yue NiuAbstract:NOAA OARNational Oceanic Atmospheric Admin (NOAA) - USA [NA18OAR4590397]; NASA MAP ProgramNational Aeronautics & Space Administration (NASA) [80NSSC17K0352]; NASA Energy and Water Cycle Study awards [NNH13ZDA001N-NEWS]
