The Experts below are selected from a list of 219 Experts worldwide ranked by ideXlab platform
Mervyn Smyth - One of the best experts on this subject based on the ideXlab platform.
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experimental characterisation of different hermetically sealed horizontal cylindrical double vessel integrated collector storage solar water Heating icsswh prototypes
Solar Energy, 2020Co-Authors: Mervyn Smyth, Aggelos Zacharopoulos, Jayanta Deb Mondol, Ronald Muhumuza, Adrian Pugsley, Dominic Mclarnon, Cesare Forzano, Annamaria Buonomano, Adolfo PalomboAbstract:Abstract Existing Integrated Collector Storage Solar Water Heaters (ICSSWHs) are typically simple and low-cost devices that combine Heat collection and storage functions in one unified vessel. However, during non-collection periods they are affected by higher Heat loss characteristics when compared to standard solar collector systems. This paper introduces the design evolution of new horizontal cylindrical ICSSWH prototypes developed at Ulster University that use novel, patented double vessel, thermal diode features (to enhance Heat Retention during non-collection periods) achieved by incorporating a liquid–vapour phase change material (PCM) with a very low pressure annular cavity. The energy performance evaluation and characterisation of different prototype designs under solar simulated experimental conditions has been conducted and the subsequent parametric analysis presented. A balance between performance and physical/operational considerations is necessary to ensure that new and practical design solutions (in materials, fabrication and assembly) can be formulated to improve the performance of the ICSSWHs within the limits of commercial reality. The importance of augmenting Heat transfer across the annulus cavity has been demonstrated with improvement of the cold-start daily collection efficiency from around (ηcol) of 20% (no HTF), to > 55% when the annulus is evacuated to remove non-condensable gases and form a liquid–vapour phase change thermal diode. Annulus thermal diode Heat transfer coefficients of around (Ufr) 35 W/m2K in forward mode and 2 W/m2K in reverse mode have been demonstrated. Diurnal thermal efficiencies ( η c o l 24 ) of 22% have been measured, but values of 39% have been identified as achievable in the longer-term development of presented ICSSWH.
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Heat retaining integrated collector storage solar water Heater with asymmetric cpc reflector
Solar Energy, 2011Co-Authors: M Souliotis, Mervyn Smyth, Patrick Quinlan, Y Tripanagnostopoulos, Aggelos Zacharopoulos, Miguel Ramirez, P YianoulisAbstract:A novel integrated collector storage solar water Heater (ICSSWH) was designed, optically analysed and experimentally studied. The unit was based around a Heat retaining ICS vessel design consisting of two concentric cylinders mounted horizontally inside a stationary truncated asymmetric compound parabolic concentrating (CPC) reflector trough. The annulus between the cylinders was partially evacuated and contained a small amount of water, which changed phase at low temperature, producing a vapour and creating a thermal diode transfer mechanism from the outer absorbing surface to the inner storage vessel surface. The absorbing outer vessel surface covered with selective absorber film and was partially exposed to solar radiation. The remaining vessel surface area (including the vessel ends) was thermally insulated to improve Heat Retention during the night. Curved reflectors with a high reflectance along with high transmittance glazing were also used to improve effective operation of the ICS system. The thermal behaviour of the ICS system was compared to that of a Flat Plate Thermosiphonic Unit (FPTU). The experimental results showed that the ICS system is as effective during daily operation as it is during the night. Furthermore, the thermal loss coefficient during night gives similar values between the ICS system and FPTU.
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a comparative performance rating for an integrated solar collector storage vessel with inner sleeves to increase Heat Retention
Solar Energy, 1999Co-Authors: Mervyn Smyth, Philip C Eames, Brian NortonAbstract:Abstract Integral Collector/Storage (ICS) solar water Heating systems suffer substantial Heat loss during periods of low insolation or at night. Methods to reduce aperture Heat loss include moveable insulated lids/shutters, transparent insulating glazing materials and selective glazing/absorber coatings. All of these approaches involve trade-offs with reduction in performance and/or an increase in cost. A novel ICS vessel design to mitigate Heat loss is proposed. An ICS vessel utilising an inner sleeve arrangement is shown to reduce Heat loss by up to 20%. This paper examines four inner sleeve design configurations, several of which demonstrate an increase in the Heat Retention capability over existing vessels, and an optimised design is presented.
Brian Norton - One of the best experts on this subject based on the ideXlab platform.
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Heat Retention of a photovoltaic thermal collector with pcm
Solar Energy, 2016Co-Authors: Maria C Browne, Brian Norton, Sarah MccormackAbstract:Abstract A novel PV/T/PCM system that generates electricity, stores Heat and pre-Heats water was characterised under outdoor conditions in Dublin, Ireland. The system design combines a PV module with a thermal collector; in which Heat is removed from a Heat exchanger embedded in PCM through a thermosyphon flow. System performance was compared against (a) the same system without PCM, (b) the same system without Heat exchanger or PCM, and (c) the PV module alone. It was shown that the temperature attained by the water was approximately 5.5 °C higher when compared to a PV/T system with no PCM. PCM are shown to be an effective means of storing Heat for later Heat removal in a PV/T system.
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a comparative performance rating for an integrated solar collector storage vessel with inner sleeves to increase Heat Retention
Solar Energy, 1999Co-Authors: Mervyn Smyth, Philip C Eames, Brian NortonAbstract:Abstract Integral Collector/Storage (ICS) solar water Heating systems suffer substantial Heat loss during periods of low insolation or at night. Methods to reduce aperture Heat loss include moveable insulated lids/shutters, transparent insulating glazing materials and selective glazing/absorber coatings. All of these approaches involve trade-offs with reduction in performance and/or an increase in cost. A novel ICS vessel design to mitigate Heat loss is proposed. An ICS vessel utilising an inner sleeve arrangement is shown to reduce Heat loss by up to 20%. This paper examines four inner sleeve design configurations, several of which demonstrate an increase in the Heat Retention capability over existing vessels, and an optimised design is presented.
Aggelos Zacharopoulos - One of the best experts on this subject based on the ideXlab platform.
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experimental characterisation of different hermetically sealed horizontal cylindrical double vessel integrated collector storage solar water Heating icsswh prototypes
Solar Energy, 2020Co-Authors: Mervyn Smyth, Aggelos Zacharopoulos, Jayanta Deb Mondol, Ronald Muhumuza, Adrian Pugsley, Dominic Mclarnon, Cesare Forzano, Annamaria Buonomano, Adolfo PalomboAbstract:Abstract Existing Integrated Collector Storage Solar Water Heaters (ICSSWHs) are typically simple and low-cost devices that combine Heat collection and storage functions in one unified vessel. However, during non-collection periods they are affected by higher Heat loss characteristics when compared to standard solar collector systems. This paper introduces the design evolution of new horizontal cylindrical ICSSWH prototypes developed at Ulster University that use novel, patented double vessel, thermal diode features (to enhance Heat Retention during non-collection periods) achieved by incorporating a liquid–vapour phase change material (PCM) with a very low pressure annular cavity. The energy performance evaluation and characterisation of different prototype designs under solar simulated experimental conditions has been conducted and the subsequent parametric analysis presented. A balance between performance and physical/operational considerations is necessary to ensure that new and practical design solutions (in materials, fabrication and assembly) can be formulated to improve the performance of the ICSSWHs within the limits of commercial reality. The importance of augmenting Heat transfer across the annulus cavity has been demonstrated with improvement of the cold-start daily collection efficiency from around (ηcol) of 20% (no HTF), to > 55% when the annulus is evacuated to remove non-condensable gases and form a liquid–vapour phase change thermal diode. Annulus thermal diode Heat transfer coefficients of around (Ufr) 35 W/m2K in forward mode and 2 W/m2K in reverse mode have been demonstrated. Diurnal thermal efficiencies ( η c o l 24 ) of 22% have been measured, but values of 39% have been identified as achievable in the longer-term development of presented ICSSWH.
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Heat retaining integrated collector storage solar water Heater with asymmetric cpc reflector
Solar Energy, 2011Co-Authors: M Souliotis, Mervyn Smyth, Patrick Quinlan, Y Tripanagnostopoulos, Aggelos Zacharopoulos, Miguel Ramirez, P YianoulisAbstract:A novel integrated collector storage solar water Heater (ICSSWH) was designed, optically analysed and experimentally studied. The unit was based around a Heat retaining ICS vessel design consisting of two concentric cylinders mounted horizontally inside a stationary truncated asymmetric compound parabolic concentrating (CPC) reflector trough. The annulus between the cylinders was partially evacuated and contained a small amount of water, which changed phase at low temperature, producing a vapour and creating a thermal diode transfer mechanism from the outer absorbing surface to the inner storage vessel surface. The absorbing outer vessel surface covered with selective absorber film and was partially exposed to solar radiation. The remaining vessel surface area (including the vessel ends) was thermally insulated to improve Heat Retention during the night. Curved reflectors with a high reflectance along with high transmittance glazing were also used to improve effective operation of the ICS system. The thermal behaviour of the ICS system was compared to that of a Flat Plate Thermosiphonic Unit (FPTU). The experimental results showed that the ICS system is as effective during daily operation as it is during the night. Furthermore, the thermal loss coefficient during night gives similar values between the ICS system and FPTU.
P Yianoulis - One of the best experts on this subject based on the ideXlab platform.
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Heat retaining integrated collector storage solar water Heater with asymmetric cpc reflector
Solar Energy, 2011Co-Authors: M Souliotis, Mervyn Smyth, Patrick Quinlan, Y Tripanagnostopoulos, Aggelos Zacharopoulos, Miguel Ramirez, P YianoulisAbstract:A novel integrated collector storage solar water Heater (ICSSWH) was designed, optically analysed and experimentally studied. The unit was based around a Heat retaining ICS vessel design consisting of two concentric cylinders mounted horizontally inside a stationary truncated asymmetric compound parabolic concentrating (CPC) reflector trough. The annulus between the cylinders was partially evacuated and contained a small amount of water, which changed phase at low temperature, producing a vapour and creating a thermal diode transfer mechanism from the outer absorbing surface to the inner storage vessel surface. The absorbing outer vessel surface covered with selective absorber film and was partially exposed to solar radiation. The remaining vessel surface area (including the vessel ends) was thermally insulated to improve Heat Retention during the night. Curved reflectors with a high reflectance along with high transmittance glazing were also used to improve effective operation of the ICS system. The thermal behaviour of the ICS system was compared to that of a Flat Plate Thermosiphonic Unit (FPTU). The experimental results showed that the ICS system is as effective during daily operation as it is during the night. Furthermore, the thermal loss coefficient during night gives similar values between the ICS system and FPTU.
Maria C Mirabelli - One of the best experts on this subject based on the ideXlab platform.
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the potential impacts of climate variability and change on temperature related morbidity and mortality in the united states
Environmental Health Perspectives, 2001Co-Authors: Michael A Mcgeehin, Maria C MirabelliAbstract:Heat and Heat waves are projected to increase in severity and frequency with increasing global mean temperatures. Studies in urban areas show an association between increases in mortality and increases in Heat, measured by maximum or minimum temperature, Heat index, and sometimes, other weather conditions. Health effects associated with exposure to extreme and prolonged Heat appear to be related to environmental temperatures above those to which the population is accustomed. Models of weather-mortality relationships indicate that populations in northeastern and midwestern U.S. cities are likely to experience the greatest number of illnesses and deaths in response to changes in summer temperature. Physiologic and behavioral adaptations may reduce morbidity and mortality. Within Heat-sensitive regions, urban populations are the most vulnerable to adverse Heat-related health outcomes. The elderly, young children, the poor, and people who are bedridden or are on certain medications are at particular risk. Heat-related illnesses and deaths are largely preventable through behavioral adaptations, including the use of air conditioning and increased fluid intake. Overall death rates are higher in winter than in summer, and it is possible that milder winters could reduce deaths in winter months. However, the relationship between winter weather and mortality is difficult to interpret. Other adaptation measures include Heat emergency plans, warning systems, and illness management plans. Research is needed to identify critical weather parameters, the associations between Heat and nonfatal illnesses, the evaluation of implemented Heat response plans, and the effectiveness of urban design in reducing Heat Retention.
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the potential impacts of climate variability and change on temperature related morbidity and mortality in the united states
Environmental Health Perspectives, 2001Co-Authors: Michael A Mcgeehin, Maria C MirabelliAbstract:Heat and Heat waves are projected to increase in severity and frequency with increasing global mean temperatures. Studies in urban areas show an association between increases in mortality and increases in Heat, measured by maximum or minimum temperature, Heat index, and sometimes, other weather conditions. Health effects associated with exposure to extreme and prolonged Heat appear to be related to environmental temperatures above those to which the population is accustomed. Models of weather‐mortality relationships indicate that populations in northeastern and midwestern U.S. cities are likely to experience the greatest number of illnesses and deaths in response to changes in summer temperature. Physiologic and behavioral adaptations may reduce morbidity and mortality. Within Heat-sensitive regions, urban populations are the most vulnerable to adverse Heat-related health outcomes. The elderly, young children, the poor, and people who are bedridden or are on certain medications are at particular risk. Heatrelated illnesses and deaths are largely preventable through behavioral adaptations, including the use of air conditioning and increased fluid intake. Overall death rates are higher in winter than in summer, and it is possible that milder winters could reduce deaths in winter months. However, the relationship between winter weather and mortality is difficult to interpret. Other adaptation measures include Heat emergency plans, warning systems, and illness management plans. Research is needed to identify critical weather parameters, the associations between Heat and nonfatal illnesses, the evaluation of implemented Heat response plans, and the effectiveness of urban design in reducing Heat Retention. Key words: climate change, cold weather, global warming, Heat waves. — Environ Health Perspect 109(suppl 2):185‐189 (2001). http://ehpnet1.niehs.nih.gov/docs/2001/suppl-2/185-189mcgeehin/abstract.html