Aliza M. Willsey, Kassidy Fields, T. Welles, Hanjie Lin, Weiwei Zheng, J. Ahn
With the depletion of fossil fuel resources, as well as increasing global temperatures, the interest in sustainable energy is on the rise. Currently, cars are a significant source of harmful emissions due to the use of internal combustion engines. Incomplete combustion byproducts are extremely harmful to the environment and the population, with links to acid rain, smog, and respiratory issues. While green energy solutions, such as electric vehicles, are being developed, the treatment of exhaust can also be an effective way to reduce the release of emissions into the atmosphere. It has been shown that a solid oxide fuel cell (SOFC) is able to break down emissions, even exceeding the capability of typical exhaust treatment methods. An investigation into the usage of an SOFC as an exhaust treatment material has found that the amplification of a signal generated across the cell has an even greater effect on emission reduction. Here, the addition of cesium lead bromide (CsPbBr3) nanocrystals to the fuel cell is being investigated. The SOFC is tested as an exhaust treatment solution and as a power generation device in comparison to a typical SOFC without added CsPbBr3 nanocrystals. CsPbBr3 is a perovskite semiconductor, so it is expected to have an effect on the reactivity of the fuel cell. Investigating the effects of adding nanocrystals into a SOFC will lead to advancements in exhaust treatment systems as well as power generation systems. The work here will show a direct relationship between the quantity of nanocrystals contained in the SOFC to the emission reduction and power generation abilities of the SOFC.
{"title":"Investigation of Emission Reduction and Power Generation on Electrochemical Catalytic Membranes With the Addition of Perovskite Nanocrystals","authors":"Aliza M. Willsey, Kassidy Fields, T. Welles, Hanjie Lin, Weiwei Zheng, J. Ahn","doi":"10.1115/imece2022-95571","DOIUrl":"https://doi.org/10.1115/imece2022-95571","url":null,"abstract":"\u0000 With the depletion of fossil fuel resources, as well as increasing global temperatures, the interest in sustainable energy is on the rise. Currently, cars are a significant source of harmful emissions due to the use of internal combustion engines. Incomplete combustion byproducts are extremely harmful to the environment and the population, with links to acid rain, smog, and respiratory issues. While green energy solutions, such as electric vehicles, are being developed, the treatment of exhaust can also be an effective way to reduce the release of emissions into the atmosphere. It has been shown that a solid oxide fuel cell (SOFC) is able to break down emissions, even exceeding the capability of typical exhaust treatment methods. An investigation into the usage of an SOFC as an exhaust treatment material has found that the amplification of a signal generated across the cell has an even greater effect on emission reduction.\u0000 Here, the addition of cesium lead bromide (CsPbBr3) nanocrystals to the fuel cell is being investigated. The SOFC is tested as an exhaust treatment solution and as a power generation device in comparison to a typical SOFC without added CsPbBr3 nanocrystals. CsPbBr3 is a perovskite semiconductor, so it is expected to have an effect on the reactivity of the fuel cell. Investigating the effects of adding nanocrystals into a SOFC will lead to advancements in exhaust treatment systems as well as power generation systems. The work here will show a direct relationship between the quantity of nanocrystals contained in the SOFC to the emission reduction and power generation abilities of the SOFC.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"10 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83613840","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}
Increasing energy demands due to rapid industrialization and urbanization, stringent emission limits, and depleting sources of conventional fossil fuels urges the scientific community in search of renewable, reliable, cost-effective, and environmentally friendly alternative and sustainable options. Biodiesel has become a center of research initiatives to address these issues as a replacement or a supplement to conventional petroleum-based fossil fuels. Biodiesel derived from waste vegetables oil and animal fat is an interesting solution to face the concerns regarding fossil fuels as well as an effective and environmentally friendly way for the disposal of waste vegetable oil in addition to reusing it for energy production. In the transportation sector, typically biodiesel is used in blends with petroleum-based diesel, and the most common blends are B5 (up to 5% biodiesel) and B20 (up to 20% biodiesel). In this regard, current manuscripts report an experimental study on the combustion characteristics of single isolated fuel droplets of different diesel-biodiesel blends. Five different diesel-biodiesel blends named B5, B10, B15, B20, and B25 were used for the droplet combustion study. Neat diesel (B0) and biodiesel (B100) followed the d2-law of combustion while the blended fuel droplets deviate from the d2-law due to puffing and micro-explosion. Increased combustion rates were observed in blended fuel droplets and the highest increase of around 7% was observed for B15 droplets compared to B0 droplets. There were no significant differences in ignition delay between B0 and blended fuel droplets while B100 fuel droplets showed an increase in ignition delay up to 38% compared to B0 droplets. B10 and B15 fuel droplets showed significant decrease in droplet burning time. Highest decrease in droplet burning time was observed for B15 which was around 8% compared to B0 droplets.
{"title":"Combustion Characteristics of Single Isolated Fuel Droplets of Different Diesel-Biodiesel Blends Derived From Waste Vegetables Oil and Animal Fat","authors":"A. S. M. S. Parveg, A. Ratner","doi":"10.1115/imece2022-95410","DOIUrl":"https://doi.org/10.1115/imece2022-95410","url":null,"abstract":"\u0000 Increasing energy demands due to rapid industrialization and urbanization, stringent emission limits, and depleting sources of conventional fossil fuels urges the scientific community in search of renewable, reliable, cost-effective, and environmentally friendly alternative and sustainable options. Biodiesel has become a center of research initiatives to address these issues as a replacement or a supplement to conventional petroleum-based fossil fuels. Biodiesel derived from waste vegetables oil and animal fat is an interesting solution to face the concerns regarding fossil fuels as well as an effective and environmentally friendly way for the disposal of waste vegetable oil in addition to reusing it for energy production. In the transportation sector, typically biodiesel is used in blends with petroleum-based diesel, and the most common blends are B5 (up to 5% biodiesel) and B20 (up to 20% biodiesel). In this regard, current manuscripts report an experimental study on the combustion characteristics of single isolated fuel droplets of different diesel-biodiesel blends. Five different diesel-biodiesel blends named B5, B10, B15, B20, and B25 were used for the droplet combustion study. Neat diesel (B0) and biodiesel (B100) followed the d2-law of combustion while the blended fuel droplets deviate from the d2-law due to puffing and micro-explosion. Increased combustion rates were observed in blended fuel droplets and the highest increase of around 7% was observed for B15 droplets compared to B0 droplets. There were no significant differences in ignition delay between B0 and blended fuel droplets while B100 fuel droplets showed an increase in ignition delay up to 38% compared to B0 droplets. B10 and B15 fuel droplets showed significant decrease in droplet burning time. Highest decrease in droplet burning time was observed for B15 which was around 8% compared to B0 droplets.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82907478","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}
J. Fajardo, Hermes Ramírez-León, D. Barreto, Carlos Rico, Camilo Cardona
A Computer Room Air Conditioner (CRAC) system has been modeled and simulated to set up a Condition-based maintenance strategy oriented on the equipment’s energy efficiency performance (MCEE). The modeling was performed using ASPEN HYSYS based on actual performance conditions of a CRAC system in the Caribbean Colombia area. The condition-based was simulated based on a fouling model increase in the evaporator and condenser, decreasing the heat transfer process and increasing the heat loss. A 2-year fouling increase model was performed to obtain an economic-technical cost-function parameter and develop a cost-effective cleaning schedule for the evaporator and condenser. The results show a 5% COP decrease due to a fouling increase. The maintenance schedule for cleaning this system is cost-effective on the 310th day. Furthermore, a Critical Matrix of the CRAC performance is developed based on energy efficiency and a cost function.
{"title":"Energy Efficiency Condition-Based Maintenance Methodology for Computer Room Air Conditioners","authors":"J. Fajardo, Hermes Ramírez-León, D. Barreto, Carlos Rico, Camilo Cardona","doi":"10.1115/imece2022-91987","DOIUrl":"https://doi.org/10.1115/imece2022-91987","url":null,"abstract":"\u0000 A Computer Room Air Conditioner (CRAC) system has been modeled and simulated to set up a Condition-based maintenance strategy oriented on the equipment’s energy efficiency performance (MCEE). The modeling was performed using ASPEN HYSYS based on actual performance conditions of a CRAC system in the Caribbean Colombia area. The condition-based was simulated based on a fouling model increase in the evaporator and condenser, decreasing the heat transfer process and increasing the heat loss. A 2-year fouling increase model was performed to obtain an economic-technical cost-function parameter and develop a cost-effective cleaning schedule for the evaporator and condenser. The results show a 5% COP decrease due to a fouling increase. The maintenance schedule for cleaning this system is cost-effective on the 310th day. Furthermore, a Critical Matrix of the CRAC performance is developed based on energy efficiency and a cost function.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76011435","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 present study aims to evaluate the intrinsic differences in in-cylinder combustion in low load and low-speed conditions by applying experimental and numerical techniques. The experimental apparatus consisted of an AVL5406 SI-PFI single-cylinder with optical access operating under two different fuel delivery methods: Port Fuel Injection (PFI) and Direct fuel Injection (DI) with anhydrous ethanol (E100) and hydrous ethanol (E96W4). The outcomes of the engine-like conditions tests were evaluated based on the quantitative analysis of the flame propagation and on the thermodynamic data obtained using INDICOM. A Video Scope VS4-1845HS high-speed camera providing cycle resolved UV-visible digital image captured the natural emission of the flame for each test. Forthwith image acquisition, the flame propagation characteristics were post-processed through image segmentation techniques. Finally, relevant literature was revised to support the results and findings obtained at this time. The contribution of this study to the internal combustion engines research remains in gathering more information about in-cylinder flame front propagation and combustion stability for E96W4 and E100 ethanol under partial load and stoichiometric and lean conditions.
{"title":"Flame Propagation Analysis of Anhydrous and Hydrous Ethanol in an Optical Spark Ignition Engine","authors":"Fernanda Pinheiro-Martins, P. Teixeira Lacava","doi":"10.1115/imece2022-89116","DOIUrl":"https://doi.org/10.1115/imece2022-89116","url":null,"abstract":"\u0000 The present study aims to evaluate the intrinsic differences in in-cylinder combustion in low load and low-speed conditions by applying experimental and numerical techniques. The experimental apparatus consisted of an AVL5406 SI-PFI single-cylinder with optical access operating under two different fuel delivery methods: Port Fuel Injection (PFI) and Direct fuel Injection (DI) with anhydrous ethanol (E100) and hydrous ethanol (E96W4).\u0000 The outcomes of the engine-like conditions tests were evaluated based on the quantitative analysis of the flame propagation and on the thermodynamic data obtained using INDICOM. A Video Scope VS4-1845HS high-speed camera providing cycle resolved UV-visible digital image captured the natural emission of the flame for each test. Forthwith image acquisition, the flame propagation characteristics were post-processed through image segmentation techniques. Finally, relevant literature was revised to support the results and findings obtained at this time.\u0000 The contribution of this study to the internal combustion engines research remains in gathering more information about in-cylinder flame front propagation and combustion stability for E96W4 and E100 ethanol under partial load and stoichiometric and lean conditions.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74968321","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}
Morgan Smith, Zachary Musgrove, Yuxin Song, Hao Hu, Shawn Duan
Great interest has been expressed in the harnessing of methane biogas from the decomposition of biowaste to combust in an electric generator to produce electricity. Biogas produced in this way is a mixture of methane gas, carbon dioxide, and hydrogen sulfide. To use this gas as a fuel for an electric generator, the gas mixture needs to be purified and dried to create a purer methane fuel in a process called upgrading. The application of such a technology has been posed as most effective in a situation where biowaste in the form of excrement, whether human or animal, is plentiful, and where conventional reliance on electric infrastructure is difficult. The Washington State Department of Transportation (WSDOT) has proposed one such application lies in the 47 safety rest areas possessed by the state. The goal of this project is to design and prototype a system which will take biowaste, in this case cow manure, and create a self-contained system which will collect and filter biogas to create methane fuel and supply this fuel to a generator modified to run on methane to produce electricity. This project successfully produced 8.5 pounds-per-square-inch of mixed biogas in an anaerobic digester and has created a filtration system to upgrade the gas for fuel in the electric generator. The mixed biogas is at a methane concentration of 100% of the lower-explosive-limit.
{"title":"Electrical Power Generation From Biogas Upgrading","authors":"Morgan Smith, Zachary Musgrove, Yuxin Song, Hao Hu, Shawn Duan","doi":"10.1115/imece2022-95280","DOIUrl":"https://doi.org/10.1115/imece2022-95280","url":null,"abstract":"\u0000 Great interest has been expressed in the harnessing of methane biogas from the decomposition of biowaste to combust in an electric generator to produce electricity. Biogas produced in this way is a mixture of methane gas, carbon dioxide, and hydrogen sulfide. To use this gas as a fuel for an electric generator, the gas mixture needs to be purified and dried to create a purer methane fuel in a process called upgrading. The application of such a technology has been posed as most effective in a situation where biowaste in the form of excrement, whether human or animal, is plentiful, and where conventional reliance on electric infrastructure is difficult. The Washington State Department of Transportation (WSDOT) has proposed one such application lies in the 47 safety rest areas possessed by the state. The goal of this project is to design and prototype a system which will take biowaste, in this case cow manure, and create a self-contained system which will collect and filter biogas to create methane fuel and supply this fuel to a generator modified to run on methane to produce electricity. This project successfully produced 8.5 pounds-per-square-inch of mixed biogas in an anaerobic digester and has created a filtration system to upgrade the gas for fuel in the electric generator. The mixed biogas is at a methane concentration of 100% of the lower-explosive-limit.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"7 18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75213845","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 provides an overview of the base model specifically developed to perform parametric sensitivity studies on the U-10Mo monolithic fuel system. U-Mo monolithic fuels are being considered for the conversion of test reactors into high-performance research reactors that operate using proliferation-resistant, low-enriched uranium (LEU) fuels. These plate-type fuels contain a high-density, low-enrichment fuel sandwiched between zirconium diffusion barriers and encapsulated in aluminum claddings. All U.S. high-performance research reactors have released the designs of their LEU monolithic fuel reactor cores. These designs include nearly 50 distinct fuel plate geometries with different operational parameters. Consequently, a single generic plate geometry representing all the extreme points in this design matrix is unrealistic. To evaluate the performance for various parameters, a set of sensitivity studies was performed. These studies considered various input parameters (i.e., geometric, operational, and material property-related). The results revealed valuable information about plate performance and the sensitivity of this performance to various modeling inputs. To establish a reference state for comparing these result, base model featuring representative irradiation conditions was developed. To capture in-reactor behavior accurately, incorporation of representative constitutive models capable of evolving properties with respect to temperature, irradiation time, and burnup was needed. The behavioral models considered burnup-dependent properties, swelling, creep, and degradation. This paper introduces the base model created for the parametric sensitivity studies. The detailed description of the procedure includes the model geometry, model discretization, thermo-mechanical coupling, material properties and behavioral models. This paper also provides selected results and assesses the performance of the base model.
{"title":"Overview of the Base Model for the Parametric Sensitivity Studies Specific to Performance Assessments of U-Mo Fuel Plates","authors":"H. Ozaltun, H. Roh, W. Mohamed","doi":"10.1115/imece2022-93718","DOIUrl":"https://doi.org/10.1115/imece2022-93718","url":null,"abstract":"\u0000 This paper provides an overview of the base model specifically developed to perform parametric sensitivity studies on the U-10Mo monolithic fuel system. U-Mo monolithic fuels are being considered for the conversion of test reactors into high-performance research reactors that operate using proliferation-resistant, low-enriched uranium (LEU) fuels. These plate-type fuels contain a high-density, low-enrichment fuel sandwiched between zirconium diffusion barriers and encapsulated in aluminum claddings. All U.S. high-performance research reactors have released the designs of their LEU monolithic fuel reactor cores. These designs include nearly 50 distinct fuel plate geometries with different operational parameters. Consequently, a single generic plate geometry representing all the extreme points in this design matrix is unrealistic. To evaluate the performance for various parameters, a set of sensitivity studies was performed. These studies considered various input parameters (i.e., geometric, operational, and material property-related). The results revealed valuable information about plate performance and the sensitivity of this performance to various modeling inputs. To establish a reference state for comparing these result, base model featuring representative irradiation conditions was developed. To capture in-reactor behavior accurately, incorporation of representative constitutive models capable of evolving properties with respect to temperature, irradiation time, and burnup was needed. The behavioral models considered burnup-dependent properties, swelling, creep, and degradation. This paper introduces the base model created for the parametric sensitivity studies. The detailed description of the procedure includes the model geometry, model discretization, thermo-mechanical coupling, material properties and behavioral models. This paper also provides selected results and assesses the performance of the base model.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82142426","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 demand for space cooling in Fiji is increasing rapidly due to a high infrastructure development rate in the country. Seawater air conditioning is a solution to the problem of space cooling using renewable energy. In this work, a feasibility study and design of a SWAC system for a university building is carried out. The feasibility study included the cooling load calculations, the availability of seawater and the location of the building. The cooling load was estimated using CAMEL software which came to be about 509 kW. Local bathymetry charts were studied to determine the depth of ocean to be 1000 m closest to the shore at which water temperatures about 6°C can be obtained. The distance from shore at which the cold water was available was approximately 12 km. A 1:15 scaled down model of the building was constructed to find the ideal chilled water supply rate and temperature. Optimal design parameters were found to be a chilled water temperature of 7°C and a cold-water flow rate of 100L/min. A temperature of 23°C was achieved inside the building after about 15 mins. The design phase of the system included the entire buildings supply and return duct system divided among 5 AHUs. The length of the seawater suction pipeline was estimated using the depth and the distance to be around 12 km. The diameter of the seawater suction pipe was optimized using cost of pipe installation and pumping power to be 0.4m, corresponding to a pumping power of 5 kW. A heat exchanger with a capacity of 500 kW, like the total cooling load of the project was selected to transfer heat between the seawater loop and the chilled water loop. The chilled water pumping power was calculated after the design of the full chilled water supply pipeline to be 4 kW. The total cost for the implementation of the SWAC system for the Marine Sciences building was estimated to be $1.04M and the payback period was estimated to be 13.8 years compared to a conventional split-type system.
{"title":"Feasibility Study and Design of a Seawater Air-Conditioning System for a University Building in Fiji","authors":"Muzammil Ali, Reemal D. Prasad, M. R. Ahmed","doi":"10.1115/imece2022-96152","DOIUrl":"https://doi.org/10.1115/imece2022-96152","url":null,"abstract":"\u0000 The demand for space cooling in Fiji is increasing rapidly due to a high infrastructure development rate in the country. Seawater air conditioning is a solution to the problem of space cooling using renewable energy. In this work, a feasibility study and design of a SWAC system for a university building is carried out. The feasibility study included the cooling load calculations, the availability of seawater and the location of the building. The cooling load was estimated using CAMEL software which came to be about 509 kW. Local bathymetry charts were studied to determine the depth of ocean to be 1000 m closest to the shore at which water temperatures about 6°C can be obtained. The distance from shore at which the cold water was available was approximately 12 km. A 1:15 scaled down model of the building was constructed to find the ideal chilled water supply rate and temperature. Optimal design parameters were found to be a chilled water temperature of 7°C and a cold-water flow rate of 100L/min. A temperature of 23°C was achieved inside the building after about 15 mins. The design phase of the system included the entire buildings supply and return duct system divided among 5 AHUs. The length of the seawater suction pipeline was estimated using the depth and the distance to be around 12 km. The diameter of the seawater suction pipe was optimized using cost of pipe installation and pumping power to be 0.4m, corresponding to a pumping power of 5 kW. A heat exchanger with a capacity of 500 kW, like the total cooling load of the project was selected to transfer heat between the seawater loop and the chilled water loop. The chilled water pumping power was calculated after the design of the full chilled water supply pipeline to be 4 kW. The total cost for the implementation of the SWAC system for the Marine Sciences building was estimated to be $1.04M and the payback period was estimated to be 13.8 years compared to a conventional split-type system.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87576064","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}
Mohamed M. Elsabahy, M. Emam, H. Sekiguchi, Mahmoud A. Ahmed
The maximum allowable concentration ratio of the silicon-based solar cells and their potential for thermal utilization applications are investigated. A three-dimensional thermal-fluid model is developed for silicon-based concentrator photovoltaics integrated with a generic heat sink. The generic heat sink is characterized by the heat transfer coefficient, resembling different scenarios of thermal management, and the heat sink temperature to reveal the potential of the CPV to provide high exergetic thermal energy. Under each combination, a wide range of concentration ratios are tested to obtain the performance characteristic maps of the solar cell, which assure the safe operation of the cell under 85°C (as recommended by manufacturers). The highest concentration ratio for the presented cell is ∼25 when the intensive cooling is applied at a heat transfer coefficient ranging from 104 – 105W/m2K under average heat sink temperature (i.e., 31°C) near the ambient one (i.e., 30°C). In addition, raising the heat sink temperature (e.g., 50°C) for thermal utilization reduces the maximum allowable concentration ratio (e.g., ∼17). Although the thermal utilization intuitively holds a higher potential at a high concentration ratio, the reverse is recommended for the solar cell when the safe operation is considered. This is attributed to the necessity of sufficiently reducing the temperature of the heat sink to draw the massive heat flux at a high concentration through the predefined solar cell thermal resistance. Consequently, low-quality thermal energy is extracted as indicated by thermal exergy efficiency. To conclude, if the objective of the CPV system is only power, working at a high concentration is recommended with a heat sink having a high heat transfer coefficient and working at a temperature nearly equal to the ambient temperature. On the other hand, if combined heat and power are intended, increasing the heat sink temperature to the target application is obtained at the cost of reducing the maximum allowable concentration ratio.
{"title":"Potentials and Limitations of Concentrator Silicon Solar Cells Energy Utilization","authors":"Mohamed M. Elsabahy, M. Emam, H. Sekiguchi, Mahmoud A. Ahmed","doi":"10.1115/imece2022-95678","DOIUrl":"https://doi.org/10.1115/imece2022-95678","url":null,"abstract":"\u0000 The maximum allowable concentration ratio of the silicon-based solar cells and their potential for thermal utilization applications are investigated. A three-dimensional thermal-fluid model is developed for silicon-based concentrator photovoltaics integrated with a generic heat sink. The generic heat sink is characterized by the heat transfer coefficient, resembling different scenarios of thermal management, and the heat sink temperature to reveal the potential of the CPV to provide high exergetic thermal energy. Under each combination, a wide range of concentration ratios are tested to obtain the performance characteristic maps of the solar cell, which assure the safe operation of the cell under 85°C (as recommended by manufacturers). The highest concentration ratio for the presented cell is ∼25 when the intensive cooling is applied at a heat transfer coefficient ranging from 104 – 105W/m2K under average heat sink temperature (i.e., 31°C) near the ambient one (i.e., 30°C). In addition, raising the heat sink temperature (e.g., 50°C) for thermal utilization reduces the maximum allowable concentration ratio (e.g., ∼17). Although the thermal utilization intuitively holds a higher potential at a high concentration ratio, the reverse is recommended for the solar cell when the safe operation is considered. This is attributed to the necessity of sufficiently reducing the temperature of the heat sink to draw the massive heat flux at a high concentration through the predefined solar cell thermal resistance. Consequently, low-quality thermal energy is extracted as indicated by thermal exergy efficiency. To conclude, if the objective of the CPV system is only power, working at a high concentration is recommended with a heat sink having a high heat transfer coefficient and working at a temperature nearly equal to the ambient temperature. On the other hand, if combined heat and power are intended, increasing the heat sink temperature to the target application is obtained at the cost of reducing the maximum allowable concentration ratio.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"92 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77859525","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}
Silicon has emerged as a frontrunner for next generation anode materials due to its high theoretical gravimetric capacity (∼4200 mAh g-1). The presence of volume changes and stress in silicon anodes introduces strong, nonlinear couplings with the lithiation and delithiation process, requiring a significant increase in the complexity of the mathematical framework describing its behavior. A mathematical description of the multiphysics coupling process is presented, requiring the simultaneous solution of the spherical diffusion equations for a binary system with volume change and stress applied to a representative particle. The resulting model description is in the form of a nonlinear set of index-2 Partial Differential and Algebraic Equations (PDAEs). This paper proposes a computationally efficient approach to solve the PDAE system, with the objective of predicting the lithium concentration, volume change, and stress generation during galvanostatic charge and discharge conditions. A semi-explicit scheme is proposed to reformulate the original system into decoupled sets of nonlinear ordinary differential equations and nonlinear algebraic equations. After a grid sensitivity analysis in the space and time domains, the proposed approach results into a computationally efficient implementation that ensures the numerical accuracy in solving this problem, for use in lithium-ion battery control and estimation applications. This study shows that a semi-explicit scheme can produce results at a rate 2.5–3.5 times faster with comparable accuracy when compared to traditional fully implicit solution methods. Limiting the number of Newton iterations in the semi-explicit scheme further reduces the semi-explicit computation time by 25 minutes.
硅因其高理论重量容量(~ 4200 mAh g-1)而成为下一代阳极材料的领跑者。硅阳极中存在的体积变化和应力引入了与锂化和衰减过程的强非线性耦合，这需要显著增加描述其行为的数学框架的复杂性。给出了一个多物理场耦合过程的数学描述，该过程要求同时求解具有体积变化和具有代表性的粒子施加应力的二元系统的球面扩散方程。所得到的模型描述是一组非线性的指标-2偏微分和代数方程(PDAEs)。本文提出了一种计算效率高的方法来求解PDAE系统，目的是预测恒流充放电条件下锂离子浓度、体积变化和应力产生。提出了一种半显式格式，将原系统转化为非线性常微分方程和非线性代数方程的解耦集。在空间和时间域中进行网格灵敏度分析后，所提出的方法得到了计算效率高的实现，确保了解决该问题的数值精度，可用于锂离子电池控制和估计应用。本研究表明，与传统的全隐式解决方法相比，半显式方案可以以2.5-3.5倍的速度产生结果，并具有相当的精度。在半显式方案中限制牛顿迭代的次数进一步减少了半显式计算时间25分钟。
{"title":"A Computationally Efficient Approach for the Simulation of Silicon Anodes in Lithium-Ion Cells","authors":"R. Webb, Xiao-liang Chen, S. Mazumder, M. Canova","doi":"10.1115/imece2022-96150","DOIUrl":"https://doi.org/10.1115/imece2022-96150","url":null,"abstract":"\u0000 Silicon has emerged as a frontrunner for next generation anode materials due to its high theoretical gravimetric capacity (∼4200 mAh g-1). The presence of volume changes and stress in silicon anodes introduces strong, nonlinear couplings with the lithiation and delithiation process, requiring a significant increase in the complexity of the mathematical framework describing its behavior.\u0000 A mathematical description of the multiphysics coupling process is presented, requiring the simultaneous solution of the spherical diffusion equations for a binary system with volume change and stress applied to a representative particle. The resulting model description is in the form of a nonlinear set of index-2 Partial Differential and Algebraic Equations (PDAEs).\u0000 This paper proposes a computationally efficient approach to solve the PDAE system, with the objective of predicting the lithium concentration, volume change, and stress generation during galvanostatic charge and discharge conditions. A semi-explicit scheme is proposed to reformulate the original system into decoupled sets of nonlinear ordinary differential equations and nonlinear algebraic equations. After a grid sensitivity analysis in the space and time domains, the proposed approach results into a computationally efficient implementation that ensures the numerical accuracy in solving this problem, for use in lithium-ion battery control and estimation applications.\u0000 This study shows that a semi-explicit scheme can produce results at a rate 2.5–3.5 times faster with comparable accuracy when compared to traditional fully implicit solution methods. Limiting the number of Newton iterations in the semi-explicit scheme further reduces the semi-explicit computation time by 25 minutes.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85337963","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 present work aims to evaluate and identify the methodology for reusing disused steam turbines in waste-to-energy plants. First, the methodology for assessing the state of the turbine will be identified through a complete overhaul of the same turbine, with attention to the components subjected to greater wear, to evaluate the possibility of reconditioning. The reference turbine will be a disused, malfunctioning and old-tech machine, often considered as “waste”, but with great potential, such that it was evaluated and finally decided to enhance it through reconditioning. The turbine overhaul operations are characterized by a first analysis of the typical failures of steam turbines, identifying the components most exposed to breakage and a deep accurate inspection has been carried out. To accomplish this task, it is necessary to know, through a completed study, the “history” of the machinery, identifying the components of the steam turbine with the highest incidence of failure. Consequently, the frequency of occurrence and the severity of the damage can be evaluated. It will be necessary to put attention to the components that present a greater risk of breakage, identifying the checks to be carried out. All possible fault chains will then be studied, highlighting the main cause and the various maintenance periods to which the turbine has been subjected. Once the functionality of the turbine has been verified, the possibility of its reuse will be evaluated, for example for geothermal plants or for waste-to-energy. Once the turbine modernization operations have been completed, the possibility of its reuse in a waste treatment plant will be analyzed. So, a pilot power plant will be studied and the possibility of using the modernized turbine within the same plant will be verified, evaluating through simulations (not included in this work) the actual feasibility and functionality of the choice made. Given the current trend in the cost of energy is growing, with a consequent increase in revenues obtainable from the use of a reconditioned turbine, a comparison of the profits deriving from the use of a revised turbine compared to the new one, also considering the time necessary for economic recovery, will be carried out. In the present work, therefore, authors wanted to underline the importance of treating waste as a source of added value (in this case the disused driving machine) and a source of energy (municipal solid waste), rather than as tasks that inevitably weigh on the finances of the State and of the individual citizen. Finally, the main goal of the work has been achieved. In fact, proven by the data, it is possible to reuse turbines after having overhauled them and take advantage in different plant applications.
{"title":"Waste Disposal Plant Application of Overhauled and Regenerated Steam Turbine","authors":"R. Capata, A. Calabria, Michele Reale","doi":"10.1115/imece2022-94916","DOIUrl":"https://doi.org/10.1115/imece2022-94916","url":null,"abstract":"\u0000 The present work aims to evaluate and identify the methodology for reusing disused steam turbines in waste-to-energy plants. First, the methodology for assessing the state of the turbine will be identified through a complete overhaul of the same turbine, with attention to the components subjected to greater wear, to evaluate the possibility of reconditioning. The reference turbine will be a disused, malfunctioning and old-tech machine, often considered as “waste”, but with great potential, such that it was evaluated and finally decided to enhance it through reconditioning. The turbine overhaul operations are characterized by a first analysis of the typical failures of steam turbines, identifying the components most exposed to breakage and a deep accurate inspection has been carried out. To accomplish this task, it is necessary to know, through a completed study, the “history” of the machinery, identifying the components of the steam turbine with the highest incidence of failure. Consequently, the frequency of occurrence and the severity of the damage can be evaluated. It will be necessary to put attention to the components that present a greater risk of breakage, identifying the checks to be carried out. All possible fault chains will then be studied, highlighting the main cause and the various maintenance periods to which the turbine has been subjected. Once the functionality of the turbine has been verified, the possibility of its reuse will be evaluated, for example for geothermal plants or for waste-to-energy. Once the turbine modernization operations have been completed, the possibility of its reuse in a waste treatment plant will be analyzed. So, a pilot power plant will be studied and the possibility of using the modernized turbine within the same plant will be verified, evaluating through simulations (not included in this work) the actual feasibility and functionality of the choice made. Given the current trend in the cost of energy is growing, with a consequent increase in revenues obtainable from the use of a reconditioned turbine, a comparison of the profits deriving from the use of a revised turbine compared to the new one, also considering the time necessary for economic recovery, will be carried out. In the present work, therefore, authors wanted to underline the importance of treating waste as a source of added value (in this case the disused driving machine) and a source of energy (municipal solid waste), rather than as tasks that inevitably weigh on the finances of the State and of the individual citizen. Finally, the main goal of the work has been achieved. In fact, proven by the data, it is possible to reuse turbines after having overhauled them and take advantage in different plant applications.","PeriodicalId":23629,"journal":{"name":"Volume 6: Energy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91233919","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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