This paper presents modeling of the Puna Geothermal Venture as a case study in understanding how the technology of geothermal can by successfully implemented. The paper presents a review of the Puna Geothermal Venture specifications, followed by simulation results carried out using NREL SAM and RETSCREEN analysis tools in order to quantify the pertinent metrics associated with the geothermal powerplant by retrofitting its current capacity of 30 MW to 60 MW. The paper closes with a review of current state-of-the art H2S abatement strategies for geothermal power plants, and presents an outline of how these technologies can be implemented at the Puna Geothermal Venture.
{"title":"Case Study of the Puna Geothermal Power Plant and Proposed Retrofit H2S Gas Mitigation Strategies","authors":"K. Anderson, Wael Yassine","doi":"10.1115/es2020-1601","DOIUrl":"https://doi.org/10.1115/es2020-1601","url":null,"abstract":"\u0000 This paper presents modeling of the Puna Geothermal Venture as a case study in understanding how the technology of geothermal can by successfully implemented. The paper presents a review of the Puna Geothermal Venture specifications, followed by simulation results carried out using NREL SAM and RETSCREEN analysis tools in order to quantify the pertinent metrics associated with the geothermal powerplant by retrofitting its current capacity of 30 MW to 60 MW. The paper closes with a review of current state-of-the art H2S abatement strategies for geothermal power plants, and presents an outline of how these technologies can be implemented at the Puna Geothermal Venture.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72703789","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 work on the design, construction and computational fluid dynamics modelling of a solar dryer with a double pass solar air collector is presented. Using fundamental relationships, an indirect solar dying system for drying banana was designed and constructed. The system consists of a drying chamber and a double pass solar collector (DPSC), connected together with a flexible aluminum pipe. The system features a unique arrangement, as the drying chamber is underneath the double pass solar collector, and the solar collector itself can be adjusted to an angle of 0° up to 35° the maintenance or research purpose. The DPSC has five longitudinal fins, lying parallel with air flow. The solar dryer is incorporated with a convective DC fan that sucks hot air from the solar collector on to the drying chamber. The DPSC achieved an optimal peak outlet temperature of 345K with a maximum operational efficiency of 72.5%. A computational fluid dynamic (CFD) model is achieved for prediction of the dryer temperature and 3D airflow distribution within the dryer unit using ANSYS 18.2. The CFD model was validated using experimental data. The developed dryer demonstrated improved efficiency over similar dryers, and this is attributable to the unique arrangement of component parts.
{"title":"Design, Construction and CFD Modeling of a Banana-Solar Dryer With Double Pass Solar Air Collector","authors":"P. Mutabilwa, Prof Kevin N. Nwaigwe","doi":"10.1115/es2020-1614","DOIUrl":"https://doi.org/10.1115/es2020-1614","url":null,"abstract":"\u0000 A work on the design, construction and computational fluid dynamics modelling of a solar dryer with a double pass solar air collector is presented. Using fundamental relationships, an indirect solar dying system for drying banana was designed and constructed. The system consists of a drying chamber and a double pass solar collector (DPSC), connected together with a flexible aluminum pipe. The system features a unique arrangement, as the drying chamber is underneath the double pass solar collector, and the solar collector itself can be adjusted to an angle of 0° up to 35° the maintenance or research purpose. The DPSC has five longitudinal fins, lying parallel with air flow. The solar dryer is incorporated with a convective DC fan that sucks hot air from the solar collector on to the drying chamber. The DPSC achieved an optimal peak outlet temperature of 345K with a maximum operational efficiency of 72.5%. A computational fluid dynamic (CFD) model is achieved for prediction of the dryer temperature and 3D airflow distribution within the dryer unit using ANSYS 18.2. The CFD model was validated using experimental data. The developed dryer demonstrated improved efficiency over similar dryers, and this is attributable to the unique arrangement of component parts.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79960567","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}
Efficient plant operation can be achieved by properly loading and sequencing available chillers to charge a thermal energy storage (TES) reservoir. TES charging sequences are often determined by heuristic rules that typically aim to reduce utility costs under time of use rates. However, such rules of thumb are in most cases far from optimal even for this task. Rigorous optimization, on the other hand, is computationally expensive and can be unreliable as well if not carefully implemented. Model-predictive control (MPC) that is reliable, as well as effective, in TES application must be developed. The goal is to develop an algorithm that can reach ∼80% of achievable energy efficiency and peak shifting capacity with very high reliability. A novel algorithm is developed to reliably achieve near optimal control for charging cool storage in chiller plants. Algorithm provides a constant COP (or cost per ton-hour) for 24-hr dispatch plan at which plant operates during most favorable weather conditions. Preliminary evaluation of this novel algorithm has indicated up to 6% improvement in plant annual operating cost relative to the same plant operating without TES. TOU rate used in both cases charges 7.4cents/kWh during off peak hours and 9.8cents/kWh during peak hours (Peak hours are 10 am to 10 pm).
{"title":"Near Optimal Model Predictive Control of Thermal Energy Storage","authors":"O. A. Qureshi, P. Armstrong","doi":"10.1115/es2020-1705","DOIUrl":"https://doi.org/10.1115/es2020-1705","url":null,"abstract":"\u0000 Efficient plant operation can be achieved by properly loading and sequencing available chillers to charge a thermal energy storage (TES) reservoir. TES charging sequences are often determined by heuristic rules that typically aim to reduce utility costs under time of use rates. However, such rules of thumb are in most cases far from optimal even for this task. Rigorous optimization, on the other hand, is computationally expensive and can be unreliable as well if not carefully implemented. Model-predictive control (MPC) that is reliable, as well as effective, in TES application must be developed. The goal is to develop an algorithm that can reach ∼80% of achievable energy efficiency and peak shifting capacity with very high reliability.\u0000 A novel algorithm is developed to reliably achieve near optimal control for charging cool storage in chiller plants. Algorithm provides a constant COP (or cost per ton-hour) for 24-hr dispatch plan at which plant operates during most favorable weather conditions. Preliminary evaluation of this novel algorithm has indicated up to 6% improvement in plant annual operating cost relative to the same plant operating without TES. TOU rate used in both cases charges 7.4cents/kWh during off peak hours and 9.8cents/kWh during peak hours (Peak hours are 10 am to 10 pm).","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77441144","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}
Following the ambitious EU plan in cutting the greenhouse emission and replacing conventional heat sources through the presence of renewable energy share inside efficient district heating fields, seasonal storage coupled with district heating plants can have a viable contribution to this goal. However, the performance uncertainty combined with the inadequate assessment regarding the financial potential and the greenhouse emission reduction associated with the deployment of those innovate district heating systems represents a great challenge for sufficiently apply it. Our work tends to explore the prospects for wide-scale deployment of the seasonal storage in the residential sector in the German market. The proposed methodology framework correspondingly based on a multi-objective approach which is applied to optimize the cost against an aggregated environmental metric throughout the life cycle of the proposed system in comparison to their relative conventional heating systems. In this context, the proposed methodology framework is applied to Berlin as a representative for the central European climate zone with consideration for the seasonal and short-term storage systems and their relatively load profiles. The environmental improvement associated with the solar district heating system (SDHS) coupled with seasonal storage in the central European climate zone is heavily weighed enough in decision making for proposing SDHS as a sustainable solution replacing the conventional heat sources. Furthermore, the proposed methodology framework successes in eliminating the yearly system variation. Thus, the yearly solar fraction never goes down below than 97.8% in the investigated climate zone. Overall this study can assist in approving the feasibility of the SDHS with the goal of establishing a more sustainable energy infrastructure in Germany.
{"title":"A Multicriteria Approach to Evaluate Solar Assisted District Heating in the German Market","authors":"M. Abokersh, M. Vallès, L. Cabeza, D. Boer","doi":"10.1115/es2020-1668","DOIUrl":"https://doi.org/10.1115/es2020-1668","url":null,"abstract":"\u0000 Following the ambitious EU plan in cutting the greenhouse emission and replacing conventional heat sources through the presence of renewable energy share inside efficient district heating fields, seasonal storage coupled with district heating plants can have a viable contribution to this goal. However, the performance uncertainty combined with the inadequate assessment regarding the financial potential and the greenhouse emission reduction associated with the deployment of those innovate district heating systems represents a great challenge for sufficiently apply it.\u0000 Our work tends to explore the prospects for wide-scale deployment of the seasonal storage in the residential sector in the German market. The proposed methodology framework correspondingly based on a multi-objective approach which is applied to optimize the cost against an aggregated environmental metric throughout the life cycle of the proposed system in comparison to their relative conventional heating systems. In this context, the proposed methodology framework is applied to Berlin as a representative for the central European climate zone with consideration for the seasonal and short-term storage systems and their relatively load profiles. The environmental improvement associated with the solar district heating system (SDHS) coupled with seasonal storage in the central European climate zone is heavily weighed enough in decision making for proposing SDHS as a sustainable solution replacing the conventional heat sources. Furthermore, the proposed methodology framework successes in eliminating the yearly system variation. Thus, the yearly solar fraction never goes down below than 97.8% in the investigated climate zone. Overall this study can assist in approving the feasibility of the SDHS with the goal of establishing a more sustainable energy infrastructure in Germany.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77415118","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}
Sonja Brankovic, Bettina K. Arkhurst, Andrey Gunawan, S. Yee
The US Department of Energy (DOE) has sponsored an initiative to improve the thermal efficiency of Concentrating Solar Power (CSP) systems. To approach parity with conventional fossil fuel-based electricity generation, the operating temperature of the CSP power cycle must exceed 700°C with integrated thermal energy storage. The materials used to house this high-temperature heat transfer media must be thermally stable and corrosion resistant. However, the temperature-dependent thermophysical properties of commonly used containment materials (nickel alloys and alumina-based firebricks) are either not well known or poorly understood. In this report, the high-temperature thermal properties of thirteen (13) candidate containment materials proposed by the CSP community are tested using laser flash analysis and differential scanning calorimetry.
{"title":"High-Temperature Thermophysical Property Measurement of Proposed Gen3 CSP Containment Materials","authors":"Sonja Brankovic, Bettina K. Arkhurst, Andrey Gunawan, S. Yee","doi":"10.1115/es2020-1687","DOIUrl":"https://doi.org/10.1115/es2020-1687","url":null,"abstract":"\u0000 The US Department of Energy (DOE) has sponsored an initiative to improve the thermal efficiency of Concentrating Solar Power (CSP) systems. To approach parity with conventional fossil fuel-based electricity generation, the operating temperature of the CSP power cycle must exceed 700°C with integrated thermal energy storage. The materials used to house this high-temperature heat transfer media must be thermally stable and corrosion resistant. However, the temperature-dependent thermophysical properties of commonly used containment materials (nickel alloys and alumina-based firebricks) are either not well known or poorly understood. In this report, the high-temperature thermal properties of thirteen (13) candidate containment materials proposed by the CSP community are tested using laser flash analysis and differential scanning calorimetry.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74496319","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}
An important factor identified for the efficiency of falling particle concentrating solar applications is the falling particle curtain opacity. Low curtain opacity results in increased radiative losses. Candidate multi-stage configurations that can increase particle-curtain opacity were simulated for the existing 1 MWth falling particle on-sun receiver at Sandia’s NSTTF. In the candidate configurations, falling particles were collected periodically in sloped troughs spanning the width of the receiver. A small lip at the front of each trough causes particles to accumulate, allowing subsequent particles to spill over. Particle surface boundary conditions were represented with an empirically based model created to approximate particle behavior observed in testing. Curtain opacity increased using a multi-stage approach and decreases in radiative losses were outweighed by decreases in advective losses which were the dominant loss mechanism. The ability to alter the flow of air within the receiver using multi-stage release resulted in the greatest efficiency gains by reducing advective losses. Additionally, multi-stage release substantially decreased back wall temperatures within receiver.
{"title":"Evaluation of Performance Factors for a Multistage Falling Particle Receiver","authors":"Reid Shaeffer, Brantley Mills, L. Yue, C. Ho","doi":"10.1115/es2020-1692","DOIUrl":"https://doi.org/10.1115/es2020-1692","url":null,"abstract":"\u0000 An important factor identified for the efficiency of falling particle concentrating solar applications is the falling particle curtain opacity. Low curtain opacity results in increased radiative losses. Candidate multi-stage configurations that can increase particle-curtain opacity were simulated for the existing 1 MWth falling particle on-sun receiver at Sandia’s NSTTF. In the candidate configurations, falling particles were collected periodically in sloped troughs spanning the width of the receiver. A small lip at the front of each trough causes particles to accumulate, allowing subsequent particles to spill over. Particle surface boundary conditions were represented with an empirically based model created to approximate particle behavior observed in testing. Curtain opacity increased using a multi-stage approach and decreases in radiative losses were outweighed by decreases in advective losses which were the dominant loss mechanism. The ability to alter the flow of air within the receiver using multi-stage release resulted in the greatest efficiency gains by reducing advective losses. Additionally, multi-stage release substantially decreased back wall temperatures within receiver.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81170378","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}
B. Far, Syed Muhammad Rizvi, Yousof Nayfeh, Donghyun Shin
Concentrated solar power (CSP) incorporated with thermal energy storage (TES) is an appealing solar energy generation technology. TES stores heat during the daytime and releases it in the nighttime. As a result, CSP can produce continuously even at night. Storing heat by TES makes CSP a unique technology among various renewable energy sources which often suffer from the intermittency of energy supply (e.g., wind turbines without wind, photovoltaics at night, etc.). The energy conversion efficiency of CSP is directly related to the properties of the TES medium. Binary or ternary mixtures of molten salts (Solar Salt) are commonly used as the TES in CSP due to its high-temperature stability. Enhancing the thermophysical properties of the molten salt medium can significantly improve TES performance. Various studies have reported the anomalous specific heat enhancement of molten salt-based nanofluids. However, the underlying mechanism for this enhancement was yet discovered. In this study, the effect of different synthesis conditions on the resultant specific heat capacity of molten salt-based nanofluids was investigated. Several molten salt nanofluids (NaNO3–KNO3 with SiO nanoparticles at 1 wt. % concentration) were prepared at different thermal cycling conditions and their thermal performance was characterized by a differential scanning calorimeter (DSC).
{"title":"Effect of Synthesis Protocol in Enhancing Heat Capacity of Molten Salt Nanofluids","authors":"B. Far, Syed Muhammad Rizvi, Yousof Nayfeh, Donghyun Shin","doi":"10.1115/es2020-1709","DOIUrl":"https://doi.org/10.1115/es2020-1709","url":null,"abstract":"\u0000 Concentrated solar power (CSP) incorporated with thermal energy storage (TES) is an appealing solar energy generation technology. TES stores heat during the daytime and releases it in the nighttime. As a result, CSP can produce continuously even at night. Storing heat by TES makes CSP a unique technology among various renewable energy sources which often suffer from the intermittency of energy supply (e.g., wind turbines without wind, photovoltaics at night, etc.). The energy conversion efficiency of CSP is directly related to the properties of the TES medium. Binary or ternary mixtures of molten salts (Solar Salt) are commonly used as the TES in CSP due to its high-temperature stability. Enhancing the thermophysical properties of the molten salt medium can significantly improve TES performance. Various studies have reported the anomalous specific heat enhancement of molten salt-based nanofluids. However, the underlying mechanism for this enhancement was yet discovered. In this study, the effect of different synthesis conditions on the resultant specific heat capacity of molten salt-based nanofluids was investigated. Several molten salt nanofluids (NaNO3–KNO3 with SiO nanoparticles at 1 wt. % concentration) were prepared at different thermal cycling conditions and their thermal performance was characterized by a differential scanning calorimeter (DSC).","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88873486","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}
M. Abokersh, H. Elayat, Mohamed Osman, M. El-Morsi
In the present study, the design of experiments (DOE) methodology is employed to statistically model and optimize the thermal performance of a forced circulation solar water heating system (FSWHS) with various budget constraints using a small number of simulation trails. The simulation trails are implemented using a model developed in TRNSYS 17 software, and climate conditions of Cairo, Egypt. A sequential approach is used to obtain the optimum system configuration with respect to the budget constraint. The definitive screening design is first utilized to eliminate the insignificant factors and investigate the effect of the quadratic terms. Then, the Box-Behnken design (BBD) is used for developing mathematical models based on multiple regression analysis. Finally, the optimization problem is formulated and solved using the desirability function. The developed mathematical models for the thermal performance responses showed a good agreement with the results obtained in TRNSYS for various budget constraints. This agreement proved the ability of the mathematical models to predict the performance of FSWHS precisely. Furthermore, the optimization methodology can be applied for various types of solar water heating systems, and different renewable energy applications.
{"title":"Application of Response Surface Model for Sizing Solar Thermal Energy System at Residential Scale During the Early Design Stages","authors":"M. Abokersh, H. Elayat, Mohamed Osman, M. El-Morsi","doi":"10.1115/es2020-1670","DOIUrl":"https://doi.org/10.1115/es2020-1670","url":null,"abstract":"\u0000 In the present study, the design of experiments (DOE) methodology is employed to statistically model and optimize the thermal performance of a forced circulation solar water heating system (FSWHS) with various budget constraints using a small number of simulation trails. The simulation trails are implemented using a model developed in TRNSYS 17 software, and climate conditions of Cairo, Egypt. A sequential approach is used to obtain the optimum system configuration with respect to the budget constraint. The definitive screening design is first utilized to eliminate the insignificant factors and investigate the effect of the quadratic terms. Then, the Box-Behnken design (BBD) is used for developing mathematical models based on multiple regression analysis. Finally, the optimization problem is formulated and solved using the desirability function. The developed mathematical models for the thermal performance responses showed a good agreement with the results obtained in TRNSYS for various budget constraints. This agreement proved the ability of the mathematical models to predict the performance of FSWHS precisely. Furthermore, the optimization methodology can be applied for various types of solar water heating systems, and different renewable energy applications.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88613781","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}
Megacities are mainly located in developing countries and face challenges in building infrastructures to ensure modern and clean energy access to citizens while coping with lifestyle changes. This paper assesses the renewables impact on energy transition for megacities (supply and all demand sectors) using the Greater Cairo megacity as case study. The MARKAL-EFOM System (TIMES) model is applied to the Greater Cairo region to investigate how energy supply and demand will evolve till 2050, and what are the impacts in terms of final energy consumption, GHG emissions, as well as share of renewable energy sources consumption in total final energy consumption considering two different emissions mitigation caps, namely 50% and 80%. Compared to the business as usual scenario, the final energy consumption decreases of 46 PJ and 57 PJ respectively in the scenarios with the CO2 cap of 50% and 80%. Besides, the TIMES-Greater Cairo shows that the fossil free energy options are limited and thus, in order to meet the emission cap, it is necessary to deploy more energy efficient technologies than in the scenarios without the cap. Transport is the sector with the higher CO2 emissions contribution and the optimization results show that it may lower the environmental impact of 28% by 2050 with the sole deployment of more efficient technologies.
{"title":"The Importance of Renewable Energy Systems in Meeting Rising Energy Needs of Megacities in a Sustainable Way: Case Study of Greater Cairo","authors":"Sara Abd Alla, V. Bianco, S. Simoes","doi":"10.1115/es2020-1629","DOIUrl":"https://doi.org/10.1115/es2020-1629","url":null,"abstract":"\u0000 Megacities are mainly located in developing countries and face challenges in building infrastructures to ensure modern and clean energy access to citizens while coping with lifestyle changes. This paper assesses the renewables impact on energy transition for megacities (supply and all demand sectors) using the Greater Cairo megacity as case study.\u0000 The MARKAL-EFOM System (TIMES) model is applied to the Greater Cairo region to investigate how energy supply and demand will evolve till 2050, and what are the impacts in terms of final energy consumption, GHG emissions, as well as share of renewable energy sources consumption in total final energy consumption considering two different emissions mitigation caps, namely 50% and 80%.\u0000 Compared to the business as usual scenario, the final energy consumption decreases of 46 PJ and 57 PJ respectively in the scenarios with the CO2 cap of 50% and 80%. Besides, the TIMES-Greater Cairo shows that the fossil free energy options are limited and thus, in order to meet the emission cap, it is necessary to deploy more energy efficient technologies than in the scenarios without the cap. Transport is the sector with the higher CO2 emissions contribution and the optimization results show that it may lower the environmental impact of 28% by 2050 with the sole deployment of more efficient technologies.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82757031","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}
Yousof Nayfeh, Syed Muhammad Rizvi, B. Far, Donghyun Shin
Recently, researchers have focused on molten-salt-based nanofluids, relying on their unique ability to form special fractallike nanostructures due to the interaction between molten salt ionic molecules and the nanoparticles. These nanostructures are thought to be causing the observed heat capacity enhancement. Thus far, this phenomenon was believed to be exclusive to molten salt nanofluids. In this study, the nanostructure observed in molten-salt-based nanofluids is mimicked, and similar fractallike nanostructures were formed in-situ in polyalphaolefin (PAO) oil as the base fluid by dispersing alumina (Al2O3) nanoparticles (1% wt. concentration) in the PAO and adding hydroxyl-ended polymer (PPG) (1% wt. concentration) as surfactants to form “artificial” nanostructures by ionically bonding to the nanoparticle’s surface. The effect of these artificial nanostructures was studied to confirm that they affect the base fluid similar to the nanostructures formed in molten salt nanofluids. Results showed an increase of 4.86% in heat capacity, and a 42% increase in viscosity was measured at high shear rates, as well as a noticeable non-Newtonian rheological behavior at low shear rates. These results show that the nanostructure has formed and that the thermophysical and rheological properties of the oil have been affected as expected.
{"title":"Nanostructure Fabrication in Oil Media for Enhanced Thermophysical Properties","authors":"Yousof Nayfeh, Syed Muhammad Rizvi, B. Far, Donghyun Shin","doi":"10.1115/es2020-1711","DOIUrl":"https://doi.org/10.1115/es2020-1711","url":null,"abstract":"\u0000 Recently, researchers have focused on molten-salt-based nanofluids, relying on their unique ability to form special fractallike nanostructures due to the interaction between molten salt ionic molecules and the nanoparticles. These nanostructures are thought to be causing the observed heat capacity enhancement. Thus far, this phenomenon was believed to be exclusive to molten salt nanofluids. In this study, the nanostructure observed in molten-salt-based nanofluids is mimicked, and similar fractallike nanostructures were formed in-situ in polyalphaolefin (PAO) oil as the base fluid by dispersing alumina (Al2O3) nanoparticles (1% wt. concentration) in the PAO and adding hydroxyl-ended polymer (PPG) (1% wt. concentration) as surfactants to form “artificial” nanostructures by ionically bonding to the nanoparticle’s surface. The effect of these artificial nanostructures was studied to confirm that they affect the base fluid similar to the nanostructures formed in molten salt nanofluids. Results showed an increase of 4.86% in heat capacity, and a 42% increase in viscosity was measured at high shear rates, as well as a noticeable non-Newtonian rheological behavior at low shear rates. These results show that the nanostructure has formed and that the thermophysical and rheological properties of the oil have been affected as expected.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83608997","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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