The static pressure, dynamic pressure and velocity magnitude are important parameters and have a strong influence on airfoil lift force. In this paper a slotted NACA4412 airfoil profile is considered for analysis by using the commercial code ANSYS-FLUENT 14.5® at an inlet boundary condition of different approaching wind velocities for various airfoil angles of attack in the range 0?to 24?. Renormalized group (RNG) k-? turbulence model with enhanced wall function is used for the analysis due its’ wide usage in the aerodynamic industry. Variations of the physical properties like static pressure, dynamic pressure and velocity magnitude are plotted in form of contours and/or vectors. The main aim of the research is to find out a method to enhance the efficiency of the selected airfoil and its’ workability in a wide range of low and high wind speeds which might make it suitable for installation and operation in different climates.This feasibility of enhancing the lift is and/or minimizing the drag is done by CFD on a series of independently modified NACA4412 airfoils. The current one is called Case 2. The analysis output of Case 2 is not encouraging. It does not show any improvement in NACA4412 airfoil efficiency and therefore it is classified as (obsolete).
{"title":"Aerodynamics Analysis of a Slotted A4412 Wind Turbine Airfoil Using CFD / Case Two","authors":"Omar Elmosrati","doi":"10.51646/JSESD.V8I2.18","DOIUrl":"https://doi.org/10.51646/JSESD.V8I2.18","url":null,"abstract":"The static pressure, dynamic pressure and velocity magnitude are important parameters and have a strong influence on airfoil lift force. In this paper a slotted NACA4412 airfoil profile is considered for analysis by using the commercial code ANSYS-FLUENT 14.5® at an inlet boundary condition of different approaching wind velocities for various airfoil angles of attack in the range 0?to 24?. Renormalized group (RNG) k-? turbulence model with enhanced wall function is used for the analysis due its’ wide usage in the aerodynamic industry. Variations of the physical properties like static pressure, dynamic pressure and velocity magnitude are plotted in form of contours and/or vectors. The main aim of the research is to find out a method to enhance the efficiency of the selected airfoil and its’ workability in a wide range of low and high wind speeds which might make it suitable for installation and operation in different climates.This feasibility of enhancing the lift is and/or minimizing the drag is done by CFD on a series of independently modified NACA4412 airfoils. The current one is called Case 2. The analysis output of Case 2 is not encouraging. It does not show any improvement in NACA4412 airfoil efficiency and therefore it is classified as (obsolete).","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115327604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The residential sector in Libya has grown over the past decade in the construction of residential buildings due to the increase in the population. Moreover, the increase in the level of income has contributed to the increase in the purchase of household appliances, which leads to increased demand for energy. Energy consumption in the household sector accounted for 31% of total energy consumption during 2010, and the share of air conditioners in this sector consumed 18.35%. To reduce energy consumption and improve energy efficiency in this sector, policies should be considered to apply energy efficiency standards and markers to household electrical appliances, as they are considered one of the most successful programs used in the world. Countries are implementing such programs to reduce energy consumption in the domestic sector. This paper presents the possibility of implementing such programs to introduce the importance of energy efficiency standards and labeling programs for home appliances in Libya. The calculations required to design such programs show the energy savings that can be achieved during cooling loads in the summer period of 4 months July, August, September). A strategic plan has been developed during 10-year (2020-2030) to estimate the expected savings of energy consumed and to identify possible obstacles and difficulties by gradually increasing the energy efficiency ratio for comestic air conditioners in two stages, from EER10 to EER11 in the first stage is then raised to EER12 as the second stage.
{"title":"The Strategy of Implementing Energy Efficiency Standards and Labels for Domestic Air Conditioners in Libya","authors":"Salah M Alabani, Ibrahim. H. Tawil","doi":"10.51646/jsesd.v8i1.28","DOIUrl":"https://doi.org/10.51646/jsesd.v8i1.28","url":null,"abstract":"The residential sector in Libya has grown over the past decade in the construction of residential buildings due to the increase in the population. Moreover, the increase in the level of income has contributed to the increase in the purchase of household appliances, which leads to increased demand for energy. Energy consumption in the household sector accounted for 31% of total energy consumption during 2010, and the share of air conditioners in this sector consumed 18.35%. To reduce energy consumption and improve energy efficiency in this sector, policies should be considered to apply energy efficiency standards and markers to household electrical appliances, as they are considered one of the most successful programs used in the world. Countries are implementing such programs to reduce energy consumption in the domestic sector. This paper presents the possibility of implementing such programs to introduce the importance of energy efficiency standards and labeling programs for home appliances in Libya. The calculations required to design such programs show the energy savings that can be achieved during cooling loads in the summer period of 4 months July, August, September). A strategic plan has been developed during 10-year (2020-2030) to estimate the expected savings of energy consumed and to identify possible obstacles and difficulties by gradually increasing the energy efficiency ratio for comestic air conditioners in two stages, from EER10 to EER11 in the first stage is then raised to EER12 as the second stage.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116947753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Ramadan, Khairi Mufth, Abdul-Gaffr Omran, Saif-Eddin Aloud
Adsorption cooling technology is one of the effctive means to convert low grade thermal energy in to effctive cooling, which improves energy effiency and lowers environmental pollution. The main objective of this study is to investigate the thermal performance of an adsorption refrigerator theoretically.The working adsorbent/adsorbate pair used is Granular Activated Carbon, GAC/R134a pair. The effct of diffrent design parameters and operating conditions on the system performance is studied and interpreted. Some assumptions and approximations are also considered. A computer program is written using Matlab. Results show that the equilibrium adsorption capacity is highly affcted by the driving temperature and equilibrium pressure. Increasing equilibrium pressure leads to a corresponding increase in the equilibrium adsorption capacity whereas it is value is decreased as the driving temperature increases. Moreover, increasing the driving and evaporator temperatures raise the values of the Specifi Cooling Effct (SCE) and Coeffient of Performance (COP). The maximum values of SCE and COP are 60 KJ/kg and 0.4 corresponding to driving and evaporator temperatures of 100 oC and 20 oC respectively. However, increasing the condenser temperature leads to a remarked decrease in SCE and COP of the cooling system. SCE and COP values are 32 KJ/kg and 0.22 at driving and condenser temperatures of 100 oC and 40 oC respectively. When comparingthe present study results with literature, there is a good agreement in general. It is clear that the adsorption cooling system can be driven effctively by low grade heat sources such as, solar energy, waste heat energy, geothermal energy…etc.
{"title":"Thoretical Study for an Adsorption Refrigerator","authors":"A. Ramadan, Khairi Mufth, Abdul-Gaffr Omran, Saif-Eddin Aloud","doi":"10.51646/jsesd.v8i1.23","DOIUrl":"https://doi.org/10.51646/jsesd.v8i1.23","url":null,"abstract":"Adsorption cooling technology is one of the effctive means to convert low grade thermal energy in to effctive cooling, which improves energy effiency and lowers environmental pollution. The main objective of this study is to investigate the thermal performance of an adsorption refrigerator theoretically.The working adsorbent/adsorbate pair used is Granular Activated Carbon, GAC/R134a pair. The effct of diffrent design parameters and operating conditions on the system performance is studied and interpreted. Some assumptions and approximations are also considered. A computer program is written using Matlab. Results show that the equilibrium adsorption capacity is highly affcted by the driving temperature and equilibrium pressure. Increasing equilibrium pressure leads to a corresponding increase in the equilibrium adsorption capacity whereas it is value is decreased as the driving temperature increases. Moreover, increasing the driving and evaporator temperatures raise the values of the Specifi Cooling Effct (SCE) and Coeffient of Performance (COP). The maximum values of SCE and COP are 60 KJ/kg and 0.4 corresponding to driving and evaporator temperatures of 100 oC and 20 oC respectively. However, increasing the condenser temperature leads to a remarked decrease in SCE and COP of the cooling system. SCE and COP values are 32 KJ/kg and 0.22 at driving and condenser temperatures of 100 oC and 40 oC respectively. When comparingthe present study results with literature, there is a good agreement in general. It is clear that the adsorption cooling system can be driven effctively by low grade heat sources such as, solar energy, waste heat energy, geothermal energy…etc.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126022780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The purpose of this study is to analyze the wind energy resource potential at Hun. Wind data was analyzed using different statistical models and calculations were performed to forecast wind energy & power density at the site. Energy production was estimated using different wind turbines which were selected according IEC standards criteria and performance of these wind turbines. Detailed wind resource data analysis was performed for the proposed site using Excel spreadsheet for one-year period from (April 2011 to March 2012). The wind data are measured at four heights of (20 m, 40m, 60m and 61m) above ground level (a.g.l). The analysis showed that the annual average wind speed is 5.69 m/s and the power density is about 190 W/m2 at 61m height. It could be noticed that at 61m height, the highest scale parameter is 7.25 m/s in April while the lowest scale parameter is 5.71 m/s in October. The annual shape and scale parameters range from 2.27 at 61m to 2 at 20m, and from 6.42 m /s at 61m to 5 m /s at 20m, respectively. 90% of the speeds are below 11m/s, 84% are below 10m/s and 50% are above 6 m/s. The maximum speed is 21 m/s with 0.14% occurrence. The wind shear exponent was evaluated as 0.18 and the roughness length for the site as 0.17 m, which indicates that the roughness class for the location is 2.5. According to the performed analysis, the wind turbines suitable for this site should be of class III/B. Comparison of three wind turbines indicated that Vestas V112-3000 gave the highest capacity factor of 42% in April and an availability of 83% while Nordex N100-2500 gave capacity factor of 41% for the same month and availability of 83.7%.
{"title":"Wind Resource Assessment for southern part of Libya: Case Study of Hun","authors":"Hiba Shreif, W. El-Osta, A. Yagub","doi":"10.51646/jsesd.v8i1.26","DOIUrl":"https://doi.org/10.51646/jsesd.v8i1.26","url":null,"abstract":"The purpose of this study is to analyze the wind energy resource potential at Hun. Wind data was analyzed using different statistical models and calculations were performed to forecast wind energy & power density at the site. Energy production was estimated using different wind turbines which were selected according IEC standards criteria and performance of these wind turbines. Detailed wind resource data analysis was performed for the proposed site using Excel spreadsheet for one-year period from (April 2011 to March 2012). The wind data are measured at four heights of (20 m, 40m, 60m and 61m) above ground level (a.g.l). The analysis showed that the annual average wind speed is 5.69 m/s and the power density is about 190 W/m2 at 61m height. It could be noticed that at 61m height, the highest scale parameter is 7.25 m/s in April while the lowest scale parameter is 5.71 m/s in October. The annual shape and scale parameters range from 2.27 at 61m to 2 at 20m, and from 6.42 m /s at 61m to 5 m /s at 20m, respectively. 90% of the speeds are below 11m/s, 84% are below 10m/s and 50% are above 6 m/s. The maximum speed is 21 m/s with 0.14% occurrence. The wind shear exponent was evaluated as 0.18 and the roughness length for the site as 0.17 m, which indicates that the roughness class for the location is 2.5. According to the performed analysis, the wind turbines suitable for this site should be of class III/B. Comparison of three wind turbines indicated that Vestas V112-3000 gave the highest capacity factor of 42% in April and an availability of 83% while Nordex N100-2500 gave capacity factor of 41% for the same month and availability of 83.7%.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114683462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ibrahim. H. Tawil, M. BenAbeid, Said O. Belhaj, Belgasim Sowid
Mosques are classified as one of the most attractive places for the Libyan people during prayer times, where ?electrical power is consumed extensively and converted into many energy types. Hot water is required for ablution during ?the cold season, which occupies 5 months per year, approximately, where electrical power is utilized to provide hot water ?demand. In this paper, the possibility of install solar water heaters in ten mosques in the city of Tripoli is studied, as the ?agreement between the General Authority of Awqaf and Islamic Affairs and CSERS states. Therefore, a detailed study is performed for site ?shading probability during the year using Climate Consultant 6.0 software, and Sketchup Make 2017. Furthermore, the solar ?water heating system is designed by (T*SOL Pro 5.5) design and simulation software. The resultant has illustrated that the employing ?of thermosyphon systems could? ?fail to fulfil water heating load in the studied mosques, due to the presence of the surrounding ?buildings shade among winter and the high water heating load of such crowded mosques. However, it is suggested to use central pumped ?solar water heating systems (forced circulation), which is able to provide high capacities with low electrical consumption. Moreover, the ?pumped systems are compatible with the conventional fuel powered systems.?
清真寺被列为利比亚人民在祈祷时间最具吸引力的地方之一，在那里电力被广泛消耗并转化为多种能源。在每年大约5个月的寒冷季节，人们需要热水来洗澡，而在这个季节，人们需要电力来提供热水。在本文中，研究了在的黎波里市的十座清真寺安装太阳能热水器的可能性，作为Awqaf和伊斯兰事务总局与CSERS之间的协议。因此，使用Climate Consultant 6.0软件和Sketchup Make 2017对一年中站点的阴影概率进行了详细的研究。利用(T*SOL Pro 5.5)设计与仿真软件对太阳能热水系统进行了设计。研究结果表明，采用热虹吸系统可以有效地提高空气质量。由于周围建筑物在冬季遮荫，以及拥挤的清真寺的高热水负荷，所研究的清真寺无法满足水加热负荷。然而，建议使用中央抽水太阳能热水系统(强制循环)，它能够提供高容量和低电力消耗。此外，泵送系统与传统的燃料动力系统兼容。
{"title":"Simulation and Evaluation of Solar Water Heating Systems availability in Mosques Sector in the City of Tripoli- Libya","authors":"Ibrahim. H. Tawil, M. BenAbeid, Said O. Belhaj, Belgasim Sowid","doi":"10.51646/jsesd.v8i1.27","DOIUrl":"https://doi.org/10.51646/jsesd.v8i1.27","url":null,"abstract":"Mosques are classified as one of the most attractive places for the Libyan people during prayer times, where ?electrical power is consumed extensively and converted into many energy types. Hot water is required for ablution during ?the cold season, which occupies 5 months per year, approximately, where electrical power is utilized to provide hot water ?demand. In this paper, the possibility of install solar water heaters in ten mosques in the city of Tripoli is studied, as the ?agreement between the General Authority of Awqaf and Islamic Affairs and CSERS states. Therefore, a detailed study is performed for site ?shading probability during the year using Climate Consultant 6.0 software, and Sketchup Make 2017. Furthermore, the solar ?water heating system is designed by (T*SOL Pro 5.5) design and simulation software. The resultant has illustrated that the employing ?of thermosyphon systems could? ?fail to fulfil water heating load in the studied mosques, due to the presence of the surrounding ?buildings shade among winter and the high water heating load of such crowded mosques. However, it is suggested to use central pumped ?solar water heating systems (forced circulation), which is able to provide high capacities with low electrical consumption. Moreover, the ?pumped systems are compatible with the conventional fuel powered systems.?","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134267308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
إبراهيم الطويل, المختار عبيد, سعيد بالحاج, بلقاسم سويد
تصنف المساجد باعتبارها أحد أكثر الأماكن جاذبية للمواطنين خلال أوقات الصلاة في ليبيا، حيث يتم استهلاك الطاقة الكهربائية على نطاق واسع وتحويلها إلى العديد من أنواع الطاقة، فالماء الساخن مطلوب للوضوء خلال موسم البرد، الذي يستمر طيلة 5 أشهر في السنة تقريباً، حيث يتم استخدام الطاقة الكهربائية لتوفير الطلب على الماء الساخن. في هذه الورقة ، تمت دراسة إمكانية ًتركيب سخانات المياه الشمسية في عشرة مساجد في مدينة طرابلس ، وفقا للاتفاق بين الهيئة العامة للأوقاف و الشؤون الإسلامية و مركز بحوث و دراسات الطاقة الشمسية CSERS، لذلك تم إجراء دراسة مفصلة لاحتمال تظليل الموقع خلال العام باستخدام برنامج استشاري المناخ 0.6 Consultant Climate و برنامج 2017 Make Sketchup ، علاوة على ذلك تم تصميم منظومة تسخين المياه بالطاقة الشمسية بواسطة برنامج (5.5 Pro SOL*T) للتصميم والمحاكاة. وقد بينت النتائج أن استخدام منظومات الدوران الطبيعي (Thermosyphon) يمكن أن يفشل في توفير حمل الماء الساخن في المساجد التي تم دراستها، وذلك بسبب وجود ظلال المباني المحيطة خلال فصل الشتاء وكذلك بسبب كبر حمل تسخين المياه لهذه المساجد المزدحمة. ومع ذلك، تم إقتراح استخدام منظومات تسخين المياه بالطاقة الشمسية ذات الدوران القسري )Circulation Forced( التي تسخدم مضخة تدوير ، والتي تكون قادرة على توفير قدرات عالية مع انخفاض استهلاك الكهرباء، علاوة على ذلك فإن الأنظمة التي يتم ضخها متوافقة مع الأنظمة التقليدية التي تعمل بالوقود.
{"title":"محاكاة و تقييم استخدام منظومات تسخين المياه بالطاقة الشمسية في المساجد داخل مدينة طرابلس- ليبيا","authors":"إبراهيم الطويل, المختار عبيد, سعيد بالحاج, بلقاسم سويد","doi":"10.51646/jsesd.v8i1.19","DOIUrl":"https://doi.org/10.51646/jsesd.v8i1.19","url":null,"abstract":"تصنف المساجد باعتبارها أحد أكثر الأماكن جاذبية للمواطنين خلال أوقات الصلاة في ليبيا، حيث يتم استهلاك الطاقة الكهربائية على نطاق واسع وتحويلها إلى العديد من أنواع الطاقة، فالماء الساخن مطلوب للوضوء خلال موسم البرد، الذي يستمر طيلة 5 أشهر في السنة تقريباً، حيث يتم استخدام الطاقة الكهربائية لتوفير الطلب على الماء الساخن. في هذه الورقة ، تمت دراسة إمكانية ًتركيب سخانات المياه الشمسية في عشرة مساجد في مدينة طرابلس ، وفقا للاتفاق بين الهيئة العامة للأوقاف و الشؤون الإسلامية و مركز بحوث و دراسات الطاقة الشمسية CSERS، لذلك تم إجراء دراسة مفصلة لاحتمال تظليل الموقع خلال العام باستخدام برنامج استشاري المناخ 0.6 Consultant Climate و برنامج 2017 Make Sketchup ، علاوة على ذلك تم تصميم منظومة تسخين المياه بالطاقة الشمسية بواسطة برنامج (5.5 Pro SOL*T) للتصميم والمحاكاة. وقد بينت النتائج أن استخدام منظومات الدوران الطبيعي (Thermosyphon) يمكن أن يفشل في توفير حمل الماء الساخن في المساجد التي تم دراستها، وذلك بسبب وجود ظلال المباني المحيطة خلال فصل الشتاء وكذلك بسبب كبر حمل تسخين المياه لهذه المساجد المزدحمة. ومع ذلك، تم إقتراح استخدام منظومات تسخين المياه بالطاقة الشمسية ذات الدوران القسري )Circulation Forced( التي تسخدم مضخة تدوير ، والتي تكون قادرة على توفير قدرات عالية مع انخفاض استهلاك الكهرباء، علاوة على ذلك فإن الأنظمة التي يتم ضخها متوافقة مع الأنظمة التقليدية التي تعمل بالوقود.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116427507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thermosyphon solar water heaters can be considered the most popular solar technology for supplying households with the needed hot water for domestic purposes. However, sizing these systems is mainly based on experience and trial methods, these methods were established more on intuition instead of scientific approaches. This paper is aimed at studying the sizing of thermosyphon systems through the development of a dedicated generic design tool. The tool can be utilized by manufacturers and engineers to arrive at optimized systems designed according to the operating and weather conditions of certain geographical locations. The design tool is implemented in this study to find the optimum system design that fits households in Libya (as a case study in this work) and accounts for the weather conditions of Tripoli and a simple, but representative, hot water load pattern. Two different sizes of thermosyphon systems covers hot water load of 180 lit and 240 lit, and two different configurations with vertical and horizontal tanks are studied and the best fit designs are obtained. The design tool has shown a great potential, and with further development and validation would be capable of widespread commercial application.
{"title":"Development of a Design Tool for Sizing and Optimizing Thermosyphon Solar Water Heater Systems: A Case Study for Tripoli-Libya","authors":"M. Abdunnabi, D.L D.L. Loveday, J. Wright","doi":"10.51646/jsesd.v8i1.25","DOIUrl":"https://doi.org/10.51646/jsesd.v8i1.25","url":null,"abstract":"Thermosyphon solar water heaters can be considered the most popular solar technology for supplying households with the needed hot water for domestic purposes. However, sizing these systems is mainly based on experience and trial methods, these methods were established more on intuition instead of scientific approaches. This paper is aimed at studying the sizing of thermosyphon systems through the development of a dedicated generic design tool. The tool can be utilized by manufacturers and engineers to arrive at optimized systems designed according to the operating and weather conditions of certain geographical locations. The design tool is implemented in this study to find the optimum system design that fits households in Libya (as a case study in this work) and accounts for the weather conditions of Tripoli and a simple, but representative, hot water load pattern. Two different sizes of thermosyphon systems covers hot water load of 180 lit and 240 lit, and two different configurations with vertical and horizontal tanks are studied and the best fit designs are obtained. The design tool has shown a great potential, and with further development and validation would be capable of widespread commercial application.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129165727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A mathematical model of the bubble pump is established by employing the governing equations; the continuity, momentum and energy equations. The model was used to evaluate the performance of the pump under different geometrical and operational conditions. Different parameters including the pump tube diameter, the pumping head, and solar heating input were considered in the analysis. The flow rates of both phases (liquid and vapor) were predicted for each set of parameters. Methanol was used as the working fluid. The performance is presented for a number of different scenarios. The flow was found to be increased with both larger diameters and low static heads, while it has a roughly sine curve with the heat input. A set of results show that for a tube diameter of 10 mm and pumping head of 450 mm, increasing the heat input from 300 W to 500 W increases the mass flow rate of vapor from 0.04 kg/sec to 0.08 kg/sec, while the liquid flow increases from 0.075 kg/sec to 0.22 kg/sec, respectively. Generally, the results of this study were found to be in fair agreement with published results.
{"title":"A Mathematical Model for The Performance of Solar Heating Driven Bubble Pumps","authors":"Khaled Elshawesh, K. R. Agha, E. Dekam","doi":"10.51646/JSESD.V7I2.71","DOIUrl":"https://doi.org/10.51646/JSESD.V7I2.71","url":null,"abstract":"A mathematical model of the bubble pump is established by employing the governing equations; the continuity, momentum and energy equations. The model was used to evaluate the performance of the pump under different geometrical and operational conditions. Different parameters including the pump tube diameter, the pumping head, and solar heating input were considered in the analysis. The flow rates of both phases (liquid and vapor) were predicted for each set of parameters. Methanol was used as the working fluid. The performance is presented for a number of different scenarios. The flow was found to be increased with both larger diameters and low static heads, while it has a roughly sine curve with the heat input. A set of results show that for a tube diameter of 10 mm and pumping head of 450 mm, increasing the heat input from 300 W to 500 W increases the mass flow rate of vapor from 0.04 kg/sec to 0.08 kg/sec, while the liquid flow increases from 0.075 kg/sec to 0.22 kg/sec, respectively. Generally, the results of this study were found to be in fair agreement with published results.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133405692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main objective of the present paper is to compare nine diffrent cell temperature models available in the literature with data measured under real Derna city climatic conditions (a semi arid climate) for month of August. Th study focuses on a comparison of nine theoretical models to calculate the cell temperature based on the experimental measurements such as the ambient temperature, irradiance, and wind speed in some of the models. Th presently used models are explicit, depending on the easily measurable parameters and of wide applicability. Six statistical quantitative indicators are used to evaluate the cell temperature models analysed, namely, R2, RMSE, RRMSE, MAE, MBE and MARE. The cell temperature correlations presently studied, fist order linear models depending on the ambient temperature, solar irradiation incident on the panel and voltage output, provide the most accurate cell temperature estimations at Derna city climatic conditions
{"title":"Validation of Thrmal Models for Polycrystalline Photovoltaic Module Under Derna City Climate Conditions","authors":"Mahmood Abdel hadi, Y. Aldali, A. Celik","doi":"10.51646/jsesd.v7i2.39","DOIUrl":"https://doi.org/10.51646/jsesd.v7i2.39","url":null,"abstract":"The main objective of the present paper is to compare nine diffrent cell temperature models available in the literature with data measured under real Derna city climatic conditions (a semi arid climate) for month of August. Th study focuses on a comparison of nine theoretical models to calculate the cell temperature based on the experimental measurements such as the ambient temperature, irradiance, and wind speed in some of the models. Th presently used models are explicit, depending on the easily measurable parameters and of wide applicability. Six statistical quantitative indicators are used to evaluate the cell temperature models analysed, namely, R2, RMSE, RRMSE, MAE, MBE and MARE. The cell temperature correlations presently studied, fist order linear models depending on the ambient temperature, solar irradiation incident on the panel and voltage output, provide the most accurate cell temperature estimations at Derna city climatic conditions","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123976050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ibrahim. H. Tawil, Mukhtar Abeid, Ezuldeen B. Abraheem, S. Alghoul, E. Dekam
This review paper focuses on documenting and studying published papers and works in the field of solar heating and cooling air space in residential buildings. The goal of this survey and documentation is to find out the most important flashing results and conclusions specifically in fields of using solar energy for space heating, cooling and ventilation of local residential buildings in Libya. This covers using active and passive solar systems in, achieving thermal human comfort in such buildings leading to reduce electrical energy consumption. This paper also concentrates on applying energy efficiency measures in buildings; planning, design, and construction stages with the use of the principles of energy conservation in buildings. There are several studies comparing traditional with modern house designs in several local cities including both famous old cities of “Ghadames” and “Gharyan”. Several conclusions and recommendations are summarized within the text of this paper.
{"title":"Review on Solar Space Heating - Cooling in Libyan Residential Buildings","authors":"Ibrahim. H. Tawil, Mukhtar Abeid, Ezuldeen B. Abraheem, S. Alghoul, E. Dekam","doi":"10.51646/JSESD.V7I3.80","DOIUrl":"https://doi.org/10.51646/JSESD.V7I3.80","url":null,"abstract":"This review paper focuses on documenting and studying published papers and works in the field of solar heating and cooling air space in residential buildings. The goal of this survey and documentation is to find out the most important flashing results and conclusions specifically in fields of using solar energy for space heating, cooling and ventilation of local residential buildings in Libya. This covers using active and passive solar systems in, achieving thermal human comfort in such buildings leading to reduce electrical energy consumption. This paper also concentrates on applying energy efficiency measures in buildings; planning, design, and construction stages with the use of the principles of energy conservation in buildings. There are several studies comparing traditional with modern house designs in several local cities including both famous old cities of “Ghadames” and “Gharyan”. Several conclusions and recommendations are summarized within the text of this paper.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124267327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：