Abstract The present work aims to analyze the economic convenience of using a reconditioned steam turbine within a waste-to-energy plant for municipal solid waste. First, the methodology for the evaluation of the functional conditions of the disused steam turbine will be identified through a complete revision of the turbine itself, paying attention to components subject to greater wear. The considered steam turbine is a disused and malfunctioning machine considered “a disposal”. The analysis of all possible fault chains and the maintenance history of the steam turbine are aimed at defining the inspection methodology to be carried out on the various components. Through appropriate simulations (not included in this work) the actual possibility of using the reconditioned steam turbine within an existing plant used as a reference plant will be evaluated. The economic evaluations and the calculation of the return time, must provide for a comparison of the purchase costs of a revised steam turbine compared to a new one, considering the revenues related to the sale of the electricity produced, the thermal power generated, and the revenues related to waste treatment. In the present work the authors wanted to underline the importance of considering the waste-to-energy of municipal solid waste as an added value rather than as a mere cost aimed only at the inertization process. In addition, it can be underlined that the use of a reconditioned steam turbine also guarantees economic convenience since the payback time is equal to two years.
{"title":"OVERHAULED AND REGENERATED STEAM TURBINE: RECONDITIONIG PROCESS AND APPLICATION","authors":"Roberto Capata, Alfonso Calabria, Michele Reale","doi":"10.1115/1.4063840","DOIUrl":"https://doi.org/10.1115/1.4063840","url":null,"abstract":"Abstract The present work aims to analyze the economic convenience of using a reconditioned steam turbine within a waste-to-energy plant for municipal solid waste. First, the methodology for the evaluation of the functional conditions of the disused steam turbine will be identified through a complete revision of the turbine itself, paying attention to components subject to greater wear. The considered steam turbine is a disused and malfunctioning machine considered “a disposal”. The analysis of all possible fault chains and the maintenance history of the steam turbine are aimed at defining the inspection methodology to be carried out on the various components. Through appropriate simulations (not included in this work) the actual possibility of using the reconditioned steam turbine within an existing plant used as a reference plant will be evaluated. The economic evaluations and the calculation of the return time, must provide for a comparison of the purchase costs of a revised steam turbine compared to a new one, considering the revenues related to the sale of the electricity produced, the thermal power generated, and the revenues related to waste treatment. In the present work the authors wanted to underline the importance of considering the waste-to-energy of municipal solid waste as an added value rather than as a mere cost aimed only at the inertization process. In addition, it can be underlined that the use of a reconditioned steam turbine also guarantees economic convenience since the payback time is equal to two years.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135824095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The performance of thermoelectric power generators (TEG) primarily depends on the properties of the thermoelectric materials employed. For conventional thermoelectric modules (TEM) utilizing the same material, the geometric parameters also play a significant role in determining TEM performance. As such, optimizing the geometry of TEM can lead to improved performance. In this study, TEM were modeled, designed, fabricated, and tested to investigate the effects of different geometric parameters on their performance. Numerical simulations were conducted under both constant temperature and constant flow boundary conditions, and the results were validated through experimental testing. The simulation results under constant flow boundary conditions exhibited good agreement with the experimental results. The effects of thickness, cross-sectional area, and filling ratio of thermoelectric legs on TEM performance were investigated through numerical simulations and compared with findings from previous studies. It was observed that increasing the cross-sectional area of the thermoelectric legs led to a decrease in the power output of TEM. Conversely, increasing the filling ratio effectively enhanced the TEM's performance. Furthermore, an optimal thermoelectric leg thickness was identified through the numerical simulations that could yield the maximum power output of TEM. The underlying mechanism behind this observation was explained, shedding light on why different reports have identified different optimal thicknesses. Optimizing the thermoelectric leg thickness can help maintain a high effective temperature difference and low internal resistance, which can vary based on the specific type of TEM and the thickness and thermal conductivity of the insulating substrates and copper sheets.
{"title":"Modeling study on the geometric optimization of thermoelectric modules","authors":"Yuhao Zhu, Kewen Li, Jianshe Linghu, Pei Yuan, Sheng Zuo, Zhenkun Weng","doi":"10.1115/1.4063837","DOIUrl":"https://doi.org/10.1115/1.4063837","url":null,"abstract":"Abstract The performance of thermoelectric power generators (TEG) primarily depends on the properties of the thermoelectric materials employed. For conventional thermoelectric modules (TEM) utilizing the same material, the geometric parameters also play a significant role in determining TEM performance. As such, optimizing the geometry of TEM can lead to improved performance. In this study, TEM were modeled, designed, fabricated, and tested to investigate the effects of different geometric parameters on their performance. Numerical simulations were conducted under both constant temperature and constant flow boundary conditions, and the results were validated through experimental testing. The simulation results under constant flow boundary conditions exhibited good agreement with the experimental results. The effects of thickness, cross-sectional area, and filling ratio of thermoelectric legs on TEM performance were investigated through numerical simulations and compared with findings from previous studies. It was observed that increasing the cross-sectional area of the thermoelectric legs led to a decrease in the power output of TEM. Conversely, increasing the filling ratio effectively enhanced the TEM's performance. Furthermore, an optimal thermoelectric leg thickness was identified through the numerical simulations that could yield the maximum power output of TEM. The underlying mechanism behind this observation was explained, shedding light on why different reports have identified different optimal thicknesses. Optimizing the thermoelectric leg thickness can help maintain a high effective temperature difference and low internal resistance, which can vary based on the specific type of TEM and the thickness and thermal conductivity of the insulating substrates and copper sheets.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135823934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jan David Ytrehus, Bjørnar Lund, Mohammad Ali Taghipour, Arild Saasen
Abstract Deviated well sections are common in most modern offshore well construction designs. In the North Sea region, which is a good example of mature areas, practically all producer or injector wells have highly deviated well sections. These wells must be constructed in an optimal manner with respect to functionality, drill time, risk and all affiliated costs. Throughout the years, most hole cleaning and hydraulic models are developed based on experimental results from relatively small scale laboratory tests with model fluids. Hole cleaning properties and hydraulic behaviour of practical drilling fluids intended for field application differ from those of most model fluids. Furthermore, results from small diameter tests may not always be relevant for, nor scalable to field applications because of presence of a huge number of dimensional quantities like velocity, fluid properties, time, length and other scale differences. Hence, studies using sufficient large scale experimental facilities in controlled laboratory environments with the application of various field designed drilling fluids are necessary to improve engineering models and operational practices. The current paper presents results from such laboratory tests where field applied drilling fluids have been used. In comparison tests the different drilling fluids have similar density and viscosity functions within the relevant field applied shear rate range. This shear rate range is also assessed in the tests. One of the drilling fluids is oil-based and the other one is an inhibitive water-based drilling fluid of the KCl/polymer type.
{"title":"Cuttings Transport With Oil- and Water-Based Drilling Fluids","authors":"Jan David Ytrehus, Bjørnar Lund, Mohammad Ali Taghipour, Arild Saasen","doi":"10.1115/1.4063838","DOIUrl":"https://doi.org/10.1115/1.4063838","url":null,"abstract":"Abstract Deviated well sections are common in most modern offshore well construction designs. In the North Sea region, which is a good example of mature areas, practically all producer or injector wells have highly deviated well sections. These wells must be constructed in an optimal manner with respect to functionality, drill time, risk and all affiliated costs. Throughout the years, most hole cleaning and hydraulic models are developed based on experimental results from relatively small scale laboratory tests with model fluids. Hole cleaning properties and hydraulic behaviour of practical drilling fluids intended for field application differ from those of most model fluids. Furthermore, results from small diameter tests may not always be relevant for, nor scalable to field applications because of presence of a huge number of dimensional quantities like velocity, fluid properties, time, length and other scale differences. Hence, studies using sufficient large scale experimental facilities in controlled laboratory environments with the application of various field designed drilling fluids are necessary to improve engineering models and operational practices. The current paper presents results from such laboratory tests where field applied drilling fluids have been used. In comparison tests the different drilling fluids have similar density and viscosity functions within the relevant field applied shear rate range. This shear rate range is also assessed in the tests. One of the drilling fluids is oil-based and the other one is an inhibitive water-based drilling fluid of the KCl/polymer type.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135823788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In this inquiry, we delve into the manner by which disparate orifice configurations exert influence upon the elevation of the jet flame when subjected to an external conflagration, employing empirical simulations. Elaborating upon the empirical dataset, we introduce the derivative of hydraulic diameter alterations and the velocity of material degradation, thereby revising the traditional non-dimensionalized model of flame altitude. The revelations disclose that, across an array of orifice profiles, the conflagration jet within oil-laden apparatus undergoes four discernible phases of evolution, each replete with variable flambeau altitudes. In disparate operational circumstances, the quantified velocity of material degradation during the evolution phase manifests an exponential interrelation with the approximated value of the model. Conversely, the phases of stability and decline adhere to a potency function connection. A quantitative delineation of the pivotal states for each phase of combustion is achieved through the evaluation of the rate of alteration in the velocity of material degradation. Significantly, the pivotal juncture for the proliferation and equilibrium stage is ascertained to be 2 g/s. This scientific inquiry confers invaluable theoretical reinforcement for fire safeguarding and catastrophe evaluation within substations accommodating oil-infused apparatus.
{"title":"Effect of Outlet Shape on Flame Height of Transformer Oil Jet Fire under External Fire Source","authors":"Shaodong Sun, Peng Chen, Xu Zhai, Yang Liu","doi":"10.1115/1.4063841","DOIUrl":"https://doi.org/10.1115/1.4063841","url":null,"abstract":"Abstract In this inquiry, we delve into the manner by which disparate orifice configurations exert influence upon the elevation of the jet flame when subjected to an external conflagration, employing empirical simulations. Elaborating upon the empirical dataset, we introduce the derivative of hydraulic diameter alterations and the velocity of material degradation, thereby revising the traditional non-dimensionalized model of flame altitude. The revelations disclose that, across an array of orifice profiles, the conflagration jet within oil-laden apparatus undergoes four discernible phases of evolution, each replete with variable flambeau altitudes. In disparate operational circumstances, the quantified velocity of material degradation during the evolution phase manifests an exponential interrelation with the approximated value of the model. Conversely, the phases of stability and decline adhere to a potency function connection. A quantitative delineation of the pivotal states for each phase of combustion is achieved through the evaluation of the rate of alteration in the velocity of material degradation. Significantly, the pivotal juncture for the proliferation and equilibrium stage is ascertained to be 2 g/s. This scientific inquiry confers invaluable theoretical reinforcement for fire safeguarding and catastrophe evaluation within substations accommodating oil-infused apparatus.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135824242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kiran Raj Goud Burra, Murat Sahin, Ying Zheng, Ashwani K. Gupta
Abstract With growing need for sustainable carbon neutral liquid fuels, and low-grade feedstocks such as lignocellulosic biomass, and municipal solid wastes offer sufficient potential via thermochemical conversion. But, existing thermochemical means are limited in feed flexibility, and scalability, require significant processing (energy and costs) of the intermediates. Bio-oil/biocrude intermediate from fast-pyrolysis and hydrothermal techniques is impeded with issues of stability and oxygen content, along with hydrotreating viability. To address these issues, we investigated a novel pathway of near-critical CO2-assisted Integrated liquefaction-extraction (NILE) technology in conceptual aspects for conversion of various biomass and municipal solid wastes into high-quality biocrude with high compatibility for co-hydrotreating with traditional fossil crude for liquid fuel needs in power and transportation sectors. Using supercritical CO2 for dewatering wet feedstocks, for liquefaction and extraction for lighter biocrude has produced biocrude with lower oxygen content by 50%, lowered metal content by 90%, stable viscosity, low acidity, and good aging stability compared to that produced from hydrothermal liquefaction along with higher hydrotreating and co-hydrotreating compatibility. Hydrotreating of the biocrude extract from sCO2 extraction also was feasible with no detected coke deposition, oxygen content of 1% and catalyst deactivation. The validation and capabilities of the NILE concept urges for its further development to obtain sustainable liquid fuels with lower GHG emissions and costs.
{"title":"Near-Critical CO2-Assisted Liquefaction-Extraction of Biomass and Wastes to Fuels and Value-Added Products","authors":"Kiran Raj Goud Burra, Murat Sahin, Ying Zheng, Ashwani K. Gupta","doi":"10.1115/1.4063813","DOIUrl":"https://doi.org/10.1115/1.4063813","url":null,"abstract":"Abstract With growing need for sustainable carbon neutral liquid fuels, and low-grade feedstocks such as lignocellulosic biomass, and municipal solid wastes offer sufficient potential via thermochemical conversion. But, existing thermochemical means are limited in feed flexibility, and scalability, require significant processing (energy and costs) of the intermediates. Bio-oil/biocrude intermediate from fast-pyrolysis and hydrothermal techniques is impeded with issues of stability and oxygen content, along with hydrotreating viability. To address these issues, we investigated a novel pathway of near-critical CO2-assisted Integrated liquefaction-extraction (NILE) technology in conceptual aspects for conversion of various biomass and municipal solid wastes into high-quality biocrude with high compatibility for co-hydrotreating with traditional fossil crude for liquid fuel needs in power and transportation sectors. Using supercritical CO2 for dewatering wet feedstocks, for liquefaction and extraction for lighter biocrude has produced biocrude with lower oxygen content by 50%, lowered metal content by 90%, stable viscosity, low acidity, and good aging stability compared to that produced from hydrothermal liquefaction along with higher hydrotreating and co-hydrotreating compatibility. Hydrotreating of the biocrude extract from sCO2 extraction also was feasible with no detected coke deposition, oxygen content of 1% and catalyst deactivation. The validation and capabilities of the NILE concept urges for its further development to obtain sustainable liquid fuels with lower GHG emissions and costs.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135994376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fengshuo He, Xinlei Feng, Zhenjia Pan, Gongjie Zhou, Yong Lu
In this study, an optimization scheme for exhaust flow characteristics based on energy splitting method is proposed. The low-speed marine diesel engine adopts the exhaust energy splitting method during the exhaust process. Based on this, a one-dimensional GT Power calculation model, a three-dimensional CONVERGE calculation model, and a three-dimensional model of the gas collection box are established. After splitting, the vortex structure in the same phase of the gas collection box has a larger scale, higher flow rate, more significant entropy increase, and more severe turbulence dissipation. The high-grade gas collection box is optimized from the perspectives of length and diameter; The results show that after optimization, the flow energy dissipation brought by the vortex structure is reduced, and the outlet pressure and flow velocity of the gas collection box are increased.
{"title":"Research and optimization on the exhaust flow characteristic based on energy splitting method of the low speed marine diesel engine","authors":"Fengshuo He, Xinlei Feng, Zhenjia Pan, Gongjie Zhou, Yong Lu","doi":"10.1115/1.4063664","DOIUrl":"https://doi.org/10.1115/1.4063664","url":null,"abstract":"In this study, an optimization scheme for exhaust flow characteristics based on energy splitting method is proposed. The low-speed marine diesel engine adopts the exhaust energy splitting method during the exhaust process. Based on this, a one-dimensional GT Power calculation model, a three-dimensional CONVERGE calculation model, and a three-dimensional model of the gas collection box are established. After splitting, the vortex structure in the same phase of the gas collection box has a larger scale, higher flow rate, more significant entropy increase, and more severe turbulence dissipation. The high-grade gas collection box is optimized from the perspectives of length and diameter; The results show that after optimization, the flow energy dissipation brought by the vortex structure is reduced, and the outlet pressure and flow velocity of the gas collection box are increased.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135435014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Carbon dioxide is the primary greenhouse gas contributing to climate change. Furthermore, due to the surplus power generated by renewable energy resources, various approaches have been developed to handle this overproduction. This study verifies via a correlation analysis the influence of the purity of hydrogen produced by a continuous surplus power on the sustainable ammonia production. The influence of the temperature and pressure of the hydrogen treatment system on the purity of the hydrogen gas produced in the alkaline water electrolysis system was investigated, where the purity increased with a decrease in temperature and an increase in pressure. The purity of the produced ammonia was positively correlated with the purity of hydrogen. Furthermore, the energy consumption of the ammonia production process increased when the purity of hydrogen was low. In the case of storing the surplus power as ammonia, the effect of hydrogen purity was less affected by the hydrogen production system than by the ammonia production system, and it was thus concluded that it is more desirable to determine the hydrogen purity in the hydrogen production system prior to employing it in the ammonia production system.
{"title":"Correlating the influence of the purity of hydrogen produced by a surplus power on the production of green ammonia","authors":"Byungjun Kim, Young Duk Lee","doi":"10.1115/1.4063663","DOIUrl":"https://doi.org/10.1115/1.4063663","url":null,"abstract":"Abstract Carbon dioxide is the primary greenhouse gas contributing to climate change. Furthermore, due to the surplus power generated by renewable energy resources, various approaches have been developed to handle this overproduction. This study verifies via a correlation analysis the influence of the purity of hydrogen produced by a continuous surplus power on the sustainable ammonia production. The influence of the temperature and pressure of the hydrogen treatment system on the purity of the hydrogen gas produced in the alkaline water electrolysis system was investigated, where the purity increased with a decrease in temperature and an increase in pressure. The purity of the produced ammonia was positively correlated with the purity of hydrogen. Furthermore, the energy consumption of the ammonia production process increased when the purity of hydrogen was low. In the case of storing the surplus power as ammonia, the effect of hydrogen purity was less affected by the hydrogen production system than by the ammonia production system, and it was thus concluded that it is more desirable to determine the hydrogen purity in the hydrogen production system prior to employing it in the ammonia production system.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134976456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Growing global concerns about fossil fuels highlight the importance of alternative fuels for internal combustion engines. Proper management of plastic waste is crucial due to its environmental impact. The pyrolysis oil process offers a sustainable solution to address plastic waste accumulation. This study explores the impact of a hydrogen-waste plastic oil blend on a modern diesel engine. Blends of diesel and plastic oil in ratios of 90:10, 80:20, and 70:30, with hydrogen supplied at 8 liters per minute, are investigated. Experiments are conducted at various loads, and hydrogen-enriched fuel blends are analyzed for combustion characteristics, performance parameters, and emissions. Higher blended fuel ratios lead to extended ignition delays, decreased thermal efficiency, and increased emissions. Hydrogen enrichment reduces carbon dioxide, hydrocarbon, and carbon monoxide emissions, but raises nitrogen oxide emissions due to higher exhaust gas temperatures. The comparative analysis shows significant improvements in brake thermal efficiency and brake-specific fuel consumption under full load conditions. The blend demonstrates notable reductions in hydrocarbon, carbon monoxide, and carbon dioxide emissions, but an increase in nitrogen oxide emissions compared to diesel. The findings indicate that integrating hydrogen into diesel engines enhances performance measures and reduces overall emissions.
{"title":"Experimental Analysis of Hydrogen Enrichment in Waste Plastic Oil Blends for Dual-Fuel Common Rail Direct Injection Diesel Engines","authors":"Tushar Anand, Sumita Debbarma","doi":"10.1115/1.4063665","DOIUrl":"https://doi.org/10.1115/1.4063665","url":null,"abstract":"Abstract Growing global concerns about fossil fuels highlight the importance of alternative fuels for internal combustion engines. Proper management of plastic waste is crucial due to its environmental impact. The pyrolysis oil process offers a sustainable solution to address plastic waste accumulation. This study explores the impact of a hydrogen-waste plastic oil blend on a modern diesel engine. Blends of diesel and plastic oil in ratios of 90:10, 80:20, and 70:30, with hydrogen supplied at 8 liters per minute, are investigated. Experiments are conducted at various loads, and hydrogen-enriched fuel blends are analyzed for combustion characteristics, performance parameters, and emissions. Higher blended fuel ratios lead to extended ignition delays, decreased thermal efficiency, and increased emissions. Hydrogen enrichment reduces carbon dioxide, hydrocarbon, and carbon monoxide emissions, but raises nitrogen oxide emissions due to higher exhaust gas temperatures. The comparative analysis shows significant improvements in brake thermal efficiency and brake-specific fuel consumption under full load conditions. The blend demonstrates notable reductions in hydrocarbon, carbon monoxide, and carbon dioxide emissions, but an increase in nitrogen oxide emissions compared to diesel. The findings indicate that integrating hydrogen into diesel engines enhances performance measures and reduces overall emissions.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134977180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The main objective of this paper is to investigate sub-grid scale turbulence-radiation interaction (SGS TRI) effects on SGS turbulence kinetic energy (TKE) fluctuations and varying thermophysical properties in a partially premixed combustion system for a laboratory-piloted methane/air flame. The large eddy simulation approach is employed to simulate the turbulence of the compressible reactive flow. SGS quantities, including turbulent stress and fluxes of enthalpy and species in the sub-grid scale, are computed using the standard Smagorinsky-Lilly model. The radiative transfer equation is modeled by applying the spherical harmonic P1 approximation by considering the radiative heat source related to the SGS TRI contribution. Optically thin fluctuation approximation is utilized to simplify the radiative absorption term. A chemical reaction mechanism comprising 41 steps and 16 species is applied to model methane/air mixture combustion. Diffusion flamelet-generated manifolds are employed to govern the species transport equation. About 87% of TKE is resolved by applying the finest grid consisting of 1,822,580 cells. Impacts of SGS TRI on the spatially filtered density, eddy viscosity, SGS velocity and TKE, overall radiative emission, RMS temperature fluctuations, and NO formation are studied. The results reveal that considering SGS TRI in the simulation leads to remarkable discrepancies, particularly in SGS velocity and TKE by 6.70% and 7.40%, respectively. Meanwhile, SGS density and eddy viscosity deviate negligibly in the presence of SGS TRI. Also, the filtered mass fraction of NO reduces up to 17.54% on average by considering TRI.
{"title":"Investigation of sub-grid scale turbulence-radiation interaction effects on turbulence energy transport and varying thermophysical properties using large eddy simulation","authors":"Farzad Bazdidi-Tehrani, Mehdi Ghiyasi","doi":"10.1115/1.4063613","DOIUrl":"https://doi.org/10.1115/1.4063613","url":null,"abstract":"Abstract The main objective of this paper is to investigate sub-grid scale turbulence-radiation interaction (SGS TRI) effects on SGS turbulence kinetic energy (TKE) fluctuations and varying thermophysical properties in a partially premixed combustion system for a laboratory-piloted methane/air flame. The large eddy simulation approach is employed to simulate the turbulence of the compressible reactive flow. SGS quantities, including turbulent stress and fluxes of enthalpy and species in the sub-grid scale, are computed using the standard Smagorinsky-Lilly model. The radiative transfer equation is modeled by applying the spherical harmonic P1 approximation by considering the radiative heat source related to the SGS TRI contribution. Optically thin fluctuation approximation is utilized to simplify the radiative absorption term. A chemical reaction mechanism comprising 41 steps and 16 species is applied to model methane/air mixture combustion. Diffusion flamelet-generated manifolds are employed to govern the species transport equation. About 87% of TKE is resolved by applying the finest grid consisting of 1,822,580 cells. Impacts of SGS TRI on the spatially filtered density, eddy viscosity, SGS velocity and TKE, overall radiative emission, RMS temperature fluctuations, and NO formation are studied. The results reveal that considering SGS TRI in the simulation leads to remarkable discrepancies, particularly in SGS velocity and TKE by 6.70% and 7.40%, respectively. Meanwhile, SGS density and eddy viscosity deviate negligibly in the presence of SGS TRI. Also, the filtered mass fraction of NO reduces up to 17.54% on average by considering TRI.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135739115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wendong Wang, Wenfeng Yu, Wang Sukai, Zhang Lipeng, Zhang Qian, Su Yuliang
Abstract Frac hits was not unfamiliar in tight gas development. During the hydraulic fracturing process in infill well, due to closely spaced wells and parent well depletion, operators often encounter communication between the fractures of parent and infill wells, resulting in frac hits. This phenomenon typically has a significant impact on the productivity of both infill and parent wells. However, effectively mitigating and minimizing the negative effects of frac hits remains challenging. We established a new frac hit mechanism and an evaluation and management workflow, aims to investigate the mechanism of frac hits between infill well and parent well and improve the performance of infill well while avoiding frac hits. The results indicate that an increased extent of parent well depletion leads to higher surrounding rock pressure and stress depletion. The stress deflection region near the fracture tip of the parent well attracts the propagation of infill well fractures, resulting in frac hits and significantly affecting the performance of parent well. Consequently, optimizing the timing of hydraulic fracturing in the infill well is beneficial for mitigating parent well depletion, controlling frac hits, and enhancing gas well productivity. This research provides important insights into mitigating parent-infill well interference in the development of tight gas reservoirs and establishes a solid foundation for future studies.
{"title":"Mitigating Interwell Fracturing Interference: Numerical Investigation of Parent Wells Depletion Affecting Infill Well Stimulation","authors":"Wendong Wang, Wenfeng Yu, Wang Sukai, Zhang Lipeng, Zhang Qian, Su Yuliang","doi":"10.1115/1.4063490","DOIUrl":"https://doi.org/10.1115/1.4063490","url":null,"abstract":"Abstract Frac hits was not unfamiliar in tight gas development. During the hydraulic fracturing process in infill well, due to closely spaced wells and parent well depletion, operators often encounter communication between the fractures of parent and infill wells, resulting in frac hits. This phenomenon typically has a significant impact on the productivity of both infill and parent wells. However, effectively mitigating and minimizing the negative effects of frac hits remains challenging. We established a new frac hit mechanism and an evaluation and management workflow, aims to investigate the mechanism of frac hits between infill well and parent well and improve the performance of infill well while avoiding frac hits. The results indicate that an increased extent of parent well depletion leads to higher surrounding rock pressure and stress depletion. The stress deflection region near the fracture tip of the parent well attracts the propagation of infill well fractures, resulting in frac hits and significantly affecting the performance of parent well. Consequently, optimizing the timing of hydraulic fracturing in the infill well is beneficial for mitigating parent well depletion, controlling frac hits, and enhancing gas well productivity. This research provides important insights into mitigating parent-infill well interference in the development of tight gas reservoirs and establishes a solid foundation for future studies.","PeriodicalId":15676,"journal":{"name":"Journal of Energy Resources Technology-transactions of The Asme","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136060944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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