This paper presents the experimental data that was collected from small pilot solar chimney. The experimental data together with ambient conditions are used to evaluate the performance and study the behavior of the solar chimney; this data will be used for comparison with theoretical models in another paper [part II). The solar chimney prototype was designed and constructed at the Subrata Faculty of Engineering-Libya. The data were collected over several days of June 2011. The solar chimney system contains two main components; the solar collector and the solar chimney. The solar collector root‘ has a circular area of126 m3, the solar chimney is a PVC tube with internal diameter of 0.2 m and the total height of chimney is 9.3 m. The measurements include the intensity of solar radiation inside/outside the collector, temperature and velocity of air at the entrance of the chimney, temperature and speed of wind outside the collector, temperature of the ground inside collector al1d temperature measurements of air at speci?c points at different levels throughout the collector. Solar irradiance was found to affect the chimney temperature and subsequently affects chimney air velocity. The experimental results showed that temperature differences of (30 - 45°C) were recorded between the ambient temperature and that of air inside the chimney in the middle of the day, where the highest air temperature of 73.4°C was recorded at the entrance of the solar chimney. The maximum air velocity of 3.6 m/s was recorded inside the solar chimney at noon on 9 June. Wind speed outside the collector had a small effect on the speed of the air inside the chimney and tends to change slightly, hence, can neglect influence of wind speed on the performance of the system. Also the experimental results indicate that such type of system can trap a suf?cient amount of solar radiation, which elevates the air temperature to a suf?cient value able to generate enough air ?ow to operate a wind turbine to produce electricity; this means the solar chimney system for electricity production can work in the north-western part of Libya in the summer time at least.
{"title":"Experimental and Theoretical Investigation of Performance of a Solar Chimney Model, Part I: Experimental Investigation","authors":"Essaied M. Shuia, B. Arebi, Ibrahim A. Abuashe","doi":"10.51646/JSESD.V3I1.48","DOIUrl":"https://doi.org/10.51646/JSESD.V3I1.48","url":null,"abstract":"This paper presents the experimental data that was collected from small pilot solar chimney. The experimental data together with ambient conditions are used to evaluate the performance and study the behavior of the solar chimney; this data will be used for comparison with theoretical models in another paper [part II). The solar chimney prototype was designed and constructed at the Subrata Faculty of Engineering-Libya. The data were collected over several days of June 2011. The solar chimney system contains two main components; the solar collector and the solar chimney. The solar collector root‘ has a circular area of126 m3, the solar chimney is a PVC tube with internal diameter of 0.2 m and the total height of chimney is 9.3 m. The measurements include the intensity of solar radiation inside/outside the collector, temperature and velocity of air at the entrance of the chimney, temperature and speed of wind outside the collector, temperature of the ground inside collector al1d temperature measurements of air at speci?c points at different levels throughout the collector. Solar irradiance was found to affect the chimney temperature and subsequently affects chimney air velocity. The experimental results showed that temperature differences of (30 - 45°C) were recorded between the ambient temperature and that of air inside the chimney in the middle of the day, where the highest air temperature of 73.4°C was recorded at the entrance of the solar chimney. The maximum air velocity of 3.6 m/s was recorded inside the solar chimney at noon on 9 June. Wind speed outside the collector had a small effect on the speed of the air inside the chimney and tends to change slightly, hence, can neglect influence of wind speed on the performance of the system. Also the experimental results indicate that such type of system can trap a suf?cient amount of solar radiation, which elevates the air temperature to a suf?cient value able to generate enough air ?ow to operate a wind turbine to produce electricity; this means the solar chimney system for electricity production can work in the north-western part of Libya in the summer time at least.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125140224","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}
With the growing global need for energy conservation to reduce the waste of natural resources which is depleting and to preserve the environment from pollutants produced from the use of such energy resources. Most countries and relevant organizations are seeking means and effective tools to achieve these targets. It could be noticed that the most effective way to tackle those issues is to apply labelling measures for the different appliances which indicated its usefulness.The paper is trying to address this issue, indicating its dimensions, prospects, importance, and mechanisms of implementation and resettlement. And also, it addresses the expected difficulties and problems, and the ways to overcome them, to actively contribute to the rationalization of energy consumption in Libya.
{"title":"Towards energy labels to rationalize consumption and saving resources in Libya","authors":"Nagemi Mahmoud Etaib, Faiza Mohamed Elgnain","doi":"10.51646/JSESD.V5I1.63","DOIUrl":"https://doi.org/10.51646/JSESD.V5I1.63","url":null,"abstract":"\u0000 \u0000 \u0000 \u0000 \u0000 \u0000With the growing global need for energy conservation to reduce the waste of natural resources which is depleting and to preserve the environment from pollutants produced from the use of such energy resources. Most countries and relevant organizations are seeking means and effective tools to achieve these targets. It could be noticed that the most effective way to tackle those issues is to apply labelling measures for the different appliances which indicated its usefulness.The paper is trying to address this issue, indicating its dimensions, prospects, importance, and mechanisms of implementation and resettlement. And also, it addresses the expected difficulties and problems, and the ways to overcome them, to actively contribute to the rationalization of energy consumption in Libya. \u0000 \u0000 \u0000","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128496495","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}
Fossil fuels (Natural gas, heavy and light oil) are considered the main sources for electricity generation in Libya. Libya’s electricity demand is growing at a rapid rate and the country will require significant additional capacity in the coming years due to the development of all sectors of life and the improvement of individuals’ life quality, without taking into account the rationalization of electricity consumption. The main reason for this is that Libya has a very high energy subsidy, especially the tariff set by the Libyan state for the price per kilowatt-hour for electricity sector. The heavily subsidized electricity price for household currently stands at (20 dirham’s/kilowatt-hour) compared to (100 dirham’s/kilowatt-hour), as the domestic price of fuel cost, and in return (450 dirham’s/kilowatt-hour) as the electricity cost of fuel in international prices. In order to reduce the deficit and the ongoing balancing in energy demand with the amount of generation of available capacity it is necessary to study all electrical systems for the future, the most important of which are wind energy and solar energy projects to meet a significant part of this demand, and to reduce, as much as possible, the carbon dioxide emissions. This paper deals with the wind data processing at the site coupled with the city and its relationship to electricity generation. It presents long term wind data analysis, in terms of averages of ten minute values of wind speed were used to get yearly mean values for a period of 1 year, between 04/11/2002 and 30/12/2003. Most frequent wind directions are NW, N, NNW and WNW. They represent about 50%, followed by E, ESE and SE. In general, East and SE winds are relatively frequent but weak at the same time. The most powerful directions are NW, WNW, W and NNW which by far - represent about 46% of the expected power, followed by N. It should be noted that the high frequency of north direction winds that come from the desert can cause a high frequency of dust episodes. This fact should be taken into consideration in order to take appropriate measures to prevent wind turbine deterioration. The annual energy yield and wind direction were evaluated for AL-Magrun town, considering wind turbines ranging between 1.65 MW and 2 MW (power curve considering air density 1.225 kg/m3). The wind turbine (Gamesa 90/2000) recorded the highest values, equaling (6.05GWh,3023Eqh) and (M. Torres TWT 1.65-82 ) equaling (4.39 GWh, 2660 Eqh) compared to the rest of the turbines studied. These values encouraged us to take advantage of wind power to achieve economic benefits.
{"title":"Wind Energy Resources Estimation and Assessment For AL-Maqrun Town - Libya","authors":"F. Ahwide, A. Ismail","doi":"10.51646/JSESD.V5I1.61","DOIUrl":"https://doi.org/10.51646/JSESD.V5I1.61","url":null,"abstract":"Fossil fuels (Natural gas, heavy and light oil) are considered the main sources for electricity generation in Libya. Libya’s electricity demand is growing at a rapid rate and the country will require significant additional capacity in the coming years due to the development of all sectors of life and the improvement of individuals’ life quality, without taking into account the rationalization of electricity consumption. The main reason for this is that Libya has a very high energy subsidy, especially the tariff set by the Libyan state for the price per kilowatt-hour for electricity sector. The heavily subsidized electricity price for household currently stands at (20 dirham’s/kilowatt-hour) compared to (100 dirham’s/kilowatt-hour), as the domestic price of fuel cost, and in return (450 dirham’s/kilowatt-hour) as the electricity cost of fuel in international prices. In order to reduce the deficit and the ongoing balancing in energy demand with the amount of generation of available capacity it is necessary to study all electrical systems for the future, the most important of which are wind energy and solar energy projects to meet a significant part of this demand, and to reduce, as much as possible, the carbon dioxide emissions. This paper deals with the wind data processing at the site coupled with the city and its relationship to electricity generation. It presents long term wind data analysis, in terms of averages of ten minute values of wind speed were used to get yearly mean values for a period of 1 year, between 04/11/2002 and 30/12/2003. Most frequent wind directions are NW, N, NNW and WNW. They represent about 50%, followed by E, ESE and SE. In general, East and SE winds are relatively frequent but weak at the same time. The most powerful directions are NW, WNW, W and NNW which by far - represent about 46% of the expected power, followed by N. It should be noted that the high frequency of north direction winds that come from the desert can cause a high frequency of dust episodes. This fact should be taken into consideration in order to take appropriate measures to prevent wind turbine deterioration. The annual energy yield and wind direction were evaluated for AL-Magrun town, considering wind turbines ranging between 1.65 MW and 2 MW (power curve considering air density 1.225 kg/m3). The wind turbine (Gamesa 90/2000) recorded the highest values, equaling (6.05GWh,3023Eqh) and (M. Torres TWT 1.65-82 ) equaling (4.39 GWh, 2660 Eqh) compared to the rest of the turbines studied. These values encouraged us to take advantage of wind power to achieve economic benefits.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114819491","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}
This paper presents a simplified comparison to show the economic feasibility of the use of solar pumps versus conventional pumps in dripping based cultivation, such as vegetables and palm trees, especially in the agricultural area about Awjila. Some technical specifications of two models of solar pumps with two different capacities - large and small - were compared. Also compared the effect of was the productivity of the two pumps on the effectiveness of desired coverage of irrigation plans intended to palm trees and vegetables. A direct comparison was made also between the traditional pumping costs and the solar pumping of agricultural water in a particular case of a well located 500 meters from the line of conventional AC power supply. In this paper we relied on computer program approach using a trusted specialized code made by an international company manufacturing water pumps operating mainly on solar energy technology. Depending on the extrapolation and digital simulation of the processes for agricultural irrigation; solar water pumping technique recorded very high techno-economical performance rates over the traditional electrical pumping. Satisfactory results were obtained for water flows that suggest the use of smaller solar pumping systems and lowest-cost over the larger systems in the case under consideration and the like. The results have shown that solar systems have prominent economic advantage over conventional systems in the medium and long range. In general results of this research, have proven, that where water is generally available, it can successfully and at high economic feasibility benefit from the tremendous solar energy potential and its equipment in the promotion of productive long term agriculture anywhere even if is not far from the traditional transmission lines of electric power. And as solar pumping technique provides is beneficial for job opportunities, agricultural, industrial and human investment and sustainable development in many of the same regions; they need support by a set of policies, laws, facilities with financial incentives leading to the realization of this vision within the economic feasibility conditions, and including the provision of funding and market activation with human habilitation.countries through dividing them into oil producing countries and non- oil producing ones .In the third axis, tools of econometrics are used to predict the international trend and that of the Arab countries , both oil and non-oil to renewable energy . The last part estimates the standard model about the possible impact of moving energies on economic growth rates in the Arab countries. The study concluded that the growing renewable energies will be different in the constituent countries of the study sample, in addition to the weak impact of the move towards renewable energies on economic growth in the Arab countries.
{"title":"An Economical -Technical Comparison of Solar Electrical Water Pumping System Versus Conventional Electrical Water Pumping System for Agricultural Purposes in the Area of “Awjila”","authors":"Gassem Azzain, Imraga Lali","doi":"10.51646/JSESD.V5I1.64","DOIUrl":"https://doi.org/10.51646/JSESD.V5I1.64","url":null,"abstract":"This paper presents a simplified comparison to show the economic feasibility of the use of solar pumps versus conventional pumps in dripping based cultivation, such as vegetables and palm trees, especially in the agricultural area about Awjila. Some technical specifications of two models of solar pumps with two different capacities - large and small - were compared. Also compared the effect of was the productivity of the two pumps on the effectiveness of desired coverage of irrigation plans intended to palm trees and vegetables. A direct comparison was made also between the traditional pumping costs and the solar pumping of agricultural water in a particular case of a well located 500 meters from the line of conventional AC power supply. In this paper we relied on computer program approach using a trusted specialized code made by an international company manufacturing water pumps operating mainly on solar energy technology. Depending on the extrapolation and digital simulation of the processes for agricultural irrigation; solar water pumping technique recorded very high techno-economical performance rates over the traditional electrical pumping. Satisfactory results were obtained for water flows that suggest the use of smaller solar pumping systems and lowest-cost over the larger systems in the case under consideration and the like. The results have shown that solar systems have prominent economic advantage over conventional systems in the medium and long range. In general results of this research, have proven, that where water is generally available, it can successfully and at high economic feasibility benefit from the tremendous solar energy potential and its equipment in the promotion of productive long term agriculture anywhere even if is not far from the traditional transmission lines of electric power. And as solar pumping technique provides is beneficial for job opportunities, agricultural, industrial and human investment and sustainable development in many of the same regions; they need support by a set of policies, laws, facilities with financial incentives leading to the realization of this vision within the economic feasibility conditions, and including the provision of funding and market activation with human habilitation.countries through dividing them into oil producing countries and non- oil producing ones .In the third axis, tools of econometrics are used to predict the international trend and that of the Arab countries , both oil and non-oil to renewable energy . The last part estimates the standard model about the possible impact of moving energies on economic growth rates in the Arab countries. The study concluded that the growing renewable energies will be different in the constituent countries of the study sample, in addition to the weak impact of the move towards renewable energies on economic growth in the Arab countries.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131352239","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}
This inductive research is located within the theme of the management and development of renewable energy systems. In brief, It introduces the potential and ability of renewable energies available in “Wadi AL-ajal”, which is located south-west of Libya, in providing many job opportunities; in addition to power generation. Several proposed investment models in solar, wind and biomass energies in this paper show -via statistical approach- how to provide a variety of job opportunities according to investment activities proposed in the three mentioned fields of renewable energies. In conclusion, the paper confirms the availability of the earlier mentioned renewable energies in varying amounts and varying degrees, they are all able to create jobs and employment of advanced technology, which are necessary for any national program for sustainable development, with the support of economic stimuli that affect investment, such as; the market activation, human resources, and finance.
{"title":"Exploration of the potential employment opportunities in the field of renewable energies in “Wadi AL-ajal”","authors":"Gassem Azzain","doi":"10.51646/JSESD.V4I1.53","DOIUrl":"https://doi.org/10.51646/JSESD.V4I1.53","url":null,"abstract":"This inductive research is located within the theme of the management and development of renewable energy systems. In brief, It introduces the potential and ability of renewable energies available in “Wadi AL-ajal”, which is located south-west of Libya, in providing many job opportunities; in addition to power generation. Several proposed investment models in solar, wind and biomass energies in this paper show -via statistical approach- how to provide a variety of job opportunities according to investment activities proposed in the three mentioned fields of renewable energies. In conclusion, the paper confirms the availability of the earlier mentioned renewable energies in varying amounts and varying degrees, they are all able to create jobs and employment of advanced technology, which are necessary for any national program for sustainable development, with the support of economic stimuli that affect investment, such as; the market activation, human resources, and finance.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115567146","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 problem of the depletion of conventional energy sources created by the greed of industrialized nations in the burning of oil and coal, not to mention the rising of their prices and the economic problems of the developing world, is the most important reason we need to pay attention to what God blessed on our country’s renewable energy sources, and the need for their exploitation by using modern technology called green technology. Expectations indicate that renewable energy will play an increasing role in the future. Therefore, different countries will continue to monitor scientific developments that are achieved with regard to these energies, and that will undoubtedly play a leading role in achieving the sustainable development of their economies.
{"title":"The Impact of Developments in the Energy Sector on Economic Development in Algeria in Light of the Potential for the Hydrocarbon Sector Development Alternatives","authors":"Zerzar layachi, Medahi Mouhamed","doi":"10.51646/JSESD.V4I1.54","DOIUrl":"https://doi.org/10.51646/JSESD.V4I1.54","url":null,"abstract":"The problem of the depletion of conventional energy sources created by the greed of industrialized nations in the burning of oil and coal, not to mention the rising of their prices and the economic problems of the developing world, is the most important reason we need to pay attention to what God blessed on our country’s renewable energy sources, and the need for their exploitation by using modern technology called green technology. Expectations indicate that renewable energy will play an increasing role in the future. Therefore, different countries will continue to monitor scientific developments that are achieved with regard to these energies, and that will undoubtedly play a leading role in achieving the sustainable development of their economies.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116929850","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 are the best choice to be utilized in residential sector to provide the required hot water in Libya. These systems are autonomy in operation and as a result require less maintenance and hence low operation and initial costs than active system. ln this paper, GenOpt optimization technique provided in TRNSYS simulation program is used for sizing Thermosyphon systems to obtain the optimum size (namely V/A ratio) of Thermosyphon system that suits Libyan families according to the weather and operating conditions of Tripoli. The typical hot water load pattern and quantity of the Libyan families are taken from a field study conducted on a number of solar system for a whole year. Whereas, the typical weather data are taken from five year measurements recorded at CSERS weather station. The results showed that the optimum storage tank volume to collector area ratio of Thermosyphon systems is between 49-60 Lit/m2 for the most common collector characteristics ratio (equation!!) and the auxiliary heater set point temperature ranges from (45-60C).
{"title":"Optimum Values of Tank Volume to Collector Area Ratios of Thermosyphon Solar Water Heaters for Libyan Families","authors":"M. Abdunnabi","doi":"10.51646/JSESD.V1I1.30","DOIUrl":"https://doi.org/10.51646/JSESD.V1I1.30","url":null,"abstract":"Thermosyphon solar water heaters are the best choice to be utilized in residential sector to provide the required hot water in Libya. These systems are autonomy in operation and as a result require less maintenance and hence low operation and initial costs than active system. ln this paper, GenOpt optimization technique provided in TRNSYS simulation program is used for sizing Thermosyphon systems to obtain the optimum size (namely V/A ratio) of Thermosyphon system that suits Libyan families according to the weather and operating conditions of Tripoli. The typical hot water load pattern and quantity of the Libyan families are taken from a field study conducted on a number of solar system for a whole year. Whereas, the typical weather data are taken from five year measurements recorded at CSERS weather station. \u0000The results showed that the optimum storage tank volume to collector area ratio of Thermosyphon systems is between 49-60 Lit/m2 for the most common collector characteristics ratio (equation!!) and the auxiliary heater set point temperature ranges from (45-60C). ","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129618745","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 presence of Nafion ionomer as one of basic elements in the PEM fuel cell catalyst layer structure can extend the three phase contact between the reactant gases, electrolyte and the catalyst surface and make the catalyst layer active in three dimensions, since the proton can move throughout the entire catalyst layer, which would improve the PEM fuel cell performance. The main objective of this study is to examine the dependence of the optimum Nafion ionomer weight percent (wt.%), on the palladium supported carbon (Pd/C) loading in PEM fuel cell catalyst layer. The results showed that the optimum Nafion ionomer contents in the PEM fuel cell catalyst layer is dependent and inversely proportional to the amount of Pd/C loading. For catalyst layers with a Palladium supported carbon (Pd/C) loading of 4.0 ± 0.1 mg/cm2, 3.2 ± 0.1 mg/cm2, and 2.45 ± 0.05 mg/cm2, the best performance was obtained at about 33, 35, and 37 wt.% Nafion ionomer loading respectively.
{"title":"The Correlation of Palladium Supported Carbon (Pd/C) Loading and Optimum Nafion Ionomer Weight Percent (wt.%) Content in the PEM Fuel Cell Catalyst Layer","authors":"A. Sghayer, Adel Diyaf, K. Mazuz, Naji A. Issa","doi":"10.51646/JSESD.V9I1.16","DOIUrl":"https://doi.org/10.51646/JSESD.V9I1.16","url":null,"abstract":"The presence of Nafion ionomer as one of basic elements in the PEM fuel cell catalyst layer structure can extend the three phase contact between the reactant gases, electrolyte and the catalyst surface and make the catalyst layer active in three dimensions, since the proton can move throughout the entire catalyst layer, which would improve the PEM fuel cell performance. The main objective of this study is to examine the dependence of the optimum Nafion ionomer weight percent (wt.%), on the palladium supported carbon (Pd/C) loading in PEM fuel cell catalyst layer. The results showed that the optimum Nafion ionomer contents in the PEM fuel cell catalyst layer is dependent and inversely proportional to the amount of Pd/C loading. For catalyst layers with a Palladium supported carbon (Pd/C) loading of 4.0 ± 0.1 mg/cm2, 3.2 ± 0.1 mg/cm2, and 2.45 ± 0.05 mg/cm2, the best performance was obtained at about 33, 35, and 37 wt.% Nafion ionomer loading respectively.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114809505","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 reflector characteristics are negatively affected by the harsh desert weather conditions and hence the performance of the system decreases. This paper investigates the effect of two different types of moving sands “A” and “B” from Libya on the performance and safety of the solar reflectors. Samples are collected from areas that are suitable for installing CSP plants. They are in different particle sizes and chemical compositions: sand “A” with size ranges between 0.025-0.355 mm, and “B” is within 0.124-0.479 mm. The experiment outcome using sand blasting indicated that sand “A” has more influence than sand “B” as thesmall particles of “A” spread over a large area of the reflector. It is also noticed in the range studied that the speed variation effect has more impact than the mass quantity changing. For clean surfaces, the reflectivity is dropped by 2.2%, and the damaged surfaces increased about 1 mm in case of 0.5 g mass at 27 m/s storm speed. For 2g mass at 21 m/s storm speed, the roughness is found 3 mm.
{"title":"Simulation of The Effect of Libyan Sand on The Reflectance Surface of CSP","authors":"E. Endaya","doi":"10.51646/JSESD.V8I2.23","DOIUrl":"https://doi.org/10.51646/JSESD.V8I2.23","url":null,"abstract":"The reflector characteristics are negatively affected by the harsh desert weather conditions and hence the performance of the system decreases. This paper investigates the effect of two different types of moving sands “A” and “B” from Libya on the performance and safety of the solar reflectors. Samples are collected from areas that are suitable for installing CSP plants. They are in different particle sizes and chemical compositions: sand “A” with size ranges between 0.025-0.355 mm, and “B” is within 0.124-0.479 mm. The experiment outcome using sand blasting indicated that sand “A” has more influence than sand “B” as thesmall particles of “A” spread over a large area of the reflector. It is also noticed in the range studied that the speed variation effect has more impact than the mass quantity changing. For clean surfaces, the reflectivity is dropped by 2.2%, and the damaged surfaces increased about 1 mm in case of 0.5 g mass at 27 m/s storm speed. For 2g mass at 21 m/s storm speed, the roughness is found 3 mm.","PeriodicalId":232564,"journal":{"name":"Solar Energy and Sustainable Development journal","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125306020","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}
Adsorption cooling technology is one of the effective means to convert low grade thermal energy in to effective cooling, which improves energy efficiency 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 pa*ir. The effect of different 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 affected 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 Specific Cooling Effect (SCE) andCoefficient 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 comparing the present study results with literature, there is a good agreement in general. It is clear that the adsorption cooling system can be driven effectively by low grade heat sources such as, solar energy, waste heat energy, geothermal energy…etc.
{"title":"Theoretical Study for an Adsorption Refrigerator","authors":"A. Ramadan","doi":"10.51646/JSESD.V8I1.24","DOIUrl":"https://doi.org/10.51646/JSESD.V8I1.24","url":null,"abstract":"Adsorption cooling technology is one of the effective means to convert low grade thermal energy in to effective cooling, which improves energy efficiency 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 pa*ir. The effect of different 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 affected 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 Specific Cooling Effect (SCE) andCoefficient 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 comparing the present study results with literature, there is a good agreement in general. It is clear that the adsorption cooling system can be driven effectively 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":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125331836","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}
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