J. Yellowhair, C. Andraka, Kenneth Armijo, Jesus D. Ortega, Jim Clair
Designs of conventional heliostats have been varied to reduce cost, improve optical performance or both. In one case, reflective mirror area on heliostats has been increased with the goal of reducing the number of pedestals and drives and consequently reducing the cost on those components. The larger reflective areas, however, increase torques due to larger mirror weights and wind loads. Higher cost heavy-duty motors and drives must be used, which negatively impact any economic gains. To improve on optical performance, the opposite may be true where the mirror reflective areas are reduced for better control of the heliostat pointing and tracking. For smaller heliostats, gravity and wind loads are reduced, but many more heliostats must be added to provide sufficient solar flux to the receiver. For conventional heliostats, there seems to be no clear cost advantage of one heliostat design over other designs. The advantage of ganged heliostats is the pedestal and tracking motors are shared between multiple heliostats, thus can significantly reduce the cost on those components. In this paper, a new concept of cable-suspended tensile ganged heliostats is introduced, preliminary analysis is performed for optical performance and incorporated into a 10 MW conceptual power tower plant where it was compared to the performance of a baseline plant with a conventional radially staggered heliostat field. The baseline plant uses conventional heliostats and the layout optimized in System Advisor Model (SAM) tool. The ganged heliostats are suspended on two guide cables. The cables are attached to rotations arms which are anchored to end posts. The layout was optimized offline and then transferred to SAM for performance evaluation. In the initial modeling of the tensile ganged heliostats for a 10 MW power tower plant, equal heliostat spacing along the guide cables was assumed, which as suspected leads to high shading and blocking losses. The goal was then to optimize the heliostat spacing such that annual shading and blocking losses are minimized. After adjusting the spacing on tensile ganged heliostats for minimal blocking losses, the annual block/shading efficiency was greater than 90% and annual optical efficiency of the field became comparable to the conventional field at slightly above 60%.
{"title":"Optical Performance Modeling and Analysis of a Tensile Ganged Heliostat Concept","authors":"J. Yellowhair, C. Andraka, Kenneth Armijo, Jesus D. Ortega, Jim Clair","doi":"10.1115/es2019-3933","DOIUrl":"https://doi.org/10.1115/es2019-3933","url":null,"abstract":"\u0000 Designs of conventional heliostats have been varied to reduce cost, improve optical performance or both. In one case, reflective mirror area on heliostats has been increased with the goal of reducing the number of pedestals and drives and consequently reducing the cost on those components. The larger reflective areas, however, increase torques due to larger mirror weights and wind loads. Higher cost heavy-duty motors and drives must be used, which negatively impact any economic gains. To improve on optical performance, the opposite may be true where the mirror reflective areas are reduced for better control of the heliostat pointing and tracking. For smaller heliostats, gravity and wind loads are reduced, but many more heliostats must be added to provide sufficient solar flux to the receiver. For conventional heliostats, there seems to be no clear cost advantage of one heliostat design over other designs.\u0000 The advantage of ganged heliostats is the pedestal and tracking motors are shared between multiple heliostats, thus can significantly reduce the cost on those components. In this paper, a new concept of cable-suspended tensile ganged heliostats is introduced, preliminary analysis is performed for optical performance and incorporated into a 10 MW conceptual power tower plant where it was compared to the performance of a baseline plant with a conventional radially staggered heliostat field. The baseline plant uses conventional heliostats and the layout optimized in System Advisor Model (SAM) tool. The ganged heliostats are suspended on two guide cables. The cables are attached to rotations arms which are anchored to end posts. The layout was optimized offline and then transferred to SAM for performance evaluation.\u0000 In the initial modeling of the tensile ganged heliostats for a 10 MW power tower plant, equal heliostat spacing along the guide cables was assumed, which as suspected leads to high shading and blocking losses. The goal was then to optimize the heliostat spacing such that annual shading and blocking losses are minimized. After adjusting the spacing on tensile ganged heliostats for minimal blocking losses, the annual block/shading efficiency was greater than 90% and annual optical efficiency of the field became comparable to the conventional field at slightly above 60%.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126855545","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}
Amarlo Banania, E. Quiros, Jose Gabriel E. Mercado
Continuous demand for energy in order to provide to an ever-increasing global population calls for use of or integration of other alternative sources of fuel other than fossil fuels. Many countries all over the world use vegetable oils blended with neat diesel as alternative and using these biofuels can help alleviate lessen the emissions releases on the environment as well as the country’s dependency on fossil fuels. In the Philippines Coconut Methyl Ester (CME) is the primary vegetable oil used, however in this study we used four other vegetable oils which are RCO (Refined Corn Oil), RPO (Refine Palm Oil), JFO (Jahtropa Filtered Oil) and JME (Jathropa Methyl Ester) in order to investigate the possibility of their use in diesel engines. A 6.3 kW single-cylinder, four stroke cycle, direct injection engine was used for the study. This kind of engine is typically used in the Philippines for different purposes such as backup power for households, for boats, pumps and for agriculture use. The specific fuel consumption of the biodiesel blends compared to neat diesel fuel ranged from −15% to 15% with RCO and JME having higher SFC and JFO and RPO having lower SFC. Fuel conversion efficiency of the varied from −12% to 12% with JFO and RPO having higher efficiency and RCO and JME having lower efficiency. The power of the varied from −7% to 6% with RPO having lower power output, JFO having higher power output and JME and RCO having similar power output to neat diesel fuel. At full load condasition Neat Diesel Fuel blended with 15% Refined Palm Oil showed the greatest improvement in SFC while Neat Diesel Fuel blended with 10% Jathropa Filtered Oil showed the best power output.
{"title":"Experimental Study on Performance of a Single-Cylinder Engine Fuelled With Diesel and Vegetable Oil-Diesel Blends","authors":"Amarlo Banania, E. Quiros, Jose Gabriel E. Mercado","doi":"10.1115/es2019-3830","DOIUrl":"https://doi.org/10.1115/es2019-3830","url":null,"abstract":"\u0000 Continuous demand for energy in order to provide to an ever-increasing global population calls for use of or integration of other alternative sources of fuel other than fossil fuels. Many countries all over the world use vegetable oils blended with neat diesel as alternative and using these biofuels can help alleviate lessen the emissions releases on the environment as well as the country’s dependency on fossil fuels. In the Philippines Coconut Methyl Ester (CME) is the primary vegetable oil used, however in this study we used four other vegetable oils which are RCO (Refined Corn Oil), RPO (Refine Palm Oil), JFO (Jahtropa Filtered Oil) and JME (Jathropa Methyl Ester) in order to investigate the possibility of their use in diesel engines. A 6.3 kW single-cylinder, four stroke cycle, direct injection engine was used for the study. This kind of engine is typically used in the Philippines for different purposes such as backup power for households, for boats, pumps and for agriculture use. The specific fuel consumption of the biodiesel blends compared to neat diesel fuel ranged from −15% to 15% with RCO and JME having higher SFC and JFO and RPO having lower SFC. Fuel conversion efficiency of the varied from −12% to 12% with JFO and RPO having higher efficiency and RCO and JME having lower efficiency. The power of the varied from −7% to 6% with RPO having lower power output, JFO having higher power output and JME and RCO having similar power output to neat diesel fuel. At full load condasition Neat Diesel Fuel blended with 15% Refined Palm Oil showed the greatest improvement in SFC while Neat Diesel Fuel blended with 10% Jathropa Filtered Oil showed the best power output.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127375064","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}
Optimization of building energy usage presents an impactful and readily addressable industry opportunity. Commercial building operators have, over the past decade, invested in on-premise Building Management Systems (BMSs) to centrally monitor and operate building sensors and controllers. BMS configurations degrade over time due to changes in building occupancy patterns as well as from ongoing sensor and controller upgrades. Recent studies reveal that an additional 10% energy savings opportunity would be available if optimal BMS configurations were sustained. Building operators face significant challenges in keeping BMS configurations optimized. The reasons are many. First, most BMSs offer proprietary interfaces that require custom, one-off integrations for remote access. Second, inconsistent BMS data representation makes it hard to aggregate and analyze performance data in order to operate systems with maximum efficiency. Third, BMSs are often designed as single user applications, creating complications to support multiple stakeholders that collectively dictate optimal usage. We propose a hybrid cloud/on-premise model that addresses the limitations of current, on-premise BMS implementations and incorporates the benefits of new cloud technologies. Our hybrid model employs a cloud-based infrastructure “middle layer” (which we call GeoBMS) that connects the “top layer” of building performance applications with the “bottom layer” of existing brownfield BMS implementations. GeoBMS addresses BMS inaccessibility through virtualization; inconsistent data representation through common cloud data models; and lack of multi-stakeholder access through global authentication. Through published APIs, GeoBMS enables the creation of innovative building performance applications. Applications use GeoBMS APIs to access previously unavailable on-premise BMS functionality and configuration data. We illustrate using a proof-of-concept application (which we call EnergyOptimize) that optimizes energy consumption for a museum case-example.
{"title":"GeoBMS for Better Building Energy Management","authors":"K. Krishnamurthy, P. Singh, N. Sriraman","doi":"10.1115/es2019-3901","DOIUrl":"https://doi.org/10.1115/es2019-3901","url":null,"abstract":"\u0000 Optimization of building energy usage presents an impactful and readily addressable industry opportunity. Commercial building operators have, over the past decade, invested in on-premise Building Management Systems (BMSs) to centrally monitor and operate building sensors and controllers. BMS configurations degrade over time due to changes in building occupancy patterns as well as from ongoing sensor and controller upgrades. Recent studies reveal that an additional 10% energy savings opportunity would be available if optimal BMS configurations were sustained.\u0000 Building operators face significant challenges in keeping BMS configurations optimized. The reasons are many. First, most BMSs offer proprietary interfaces that require custom, one-off integrations for remote access. Second, inconsistent BMS data representation makes it hard to aggregate and analyze performance data in order to operate systems with maximum efficiency. Third, BMSs are often designed as single user applications, creating complications to support multiple stakeholders that collectively dictate optimal usage.\u0000 We propose a hybrid cloud/on-premise model that addresses the limitations of current, on-premise BMS implementations and incorporates the benefits of new cloud technologies. Our hybrid model employs a cloud-based infrastructure “middle layer” (which we call GeoBMS) that connects the “top layer” of building performance applications with the “bottom layer” of existing brownfield BMS implementations. GeoBMS addresses BMS inaccessibility through virtualization; inconsistent data representation through common cloud data models; and lack of multi-stakeholder access through global authentication.\u0000 Through published APIs, GeoBMS enables the creation of innovative building performance applications. Applications use GeoBMS APIs to access previously unavailable on-premise BMS functionality and configuration data. We illustrate using a proof-of-concept application (which we call EnergyOptimize) that optimizes energy consumption for a museum case-example.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"1952 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129238464","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}
In this paper, we focus on the Variable-Speed (VS) stall control method, a relatively new idea, which offers a promising perspective for future applications. As with the classical Fixed-Speed (FS) stall method, the elimination of the pitch mechanism, lowers the capital cost and reduces maintenance expenses, while at the same time, allows for a more efficient and precise control of power production. We present an analysis focused on the aeroe-lastic dynamic response of wind turbine rotors operating on the Variable-Speed stall control method. We conducted a wide range of experiments to assess the effects of rapid variations on the rotor’s operational conditions, like sudden gusts. Various gust conditions were tested for different wind speeds, represented by pulses of different intensity, occurring suddenly in an otherwise constant wind regime. Results for the aeroelastic dynamics of the rotor’s response, and the frequency content of its vibrations, are reported and analyzed.
{"title":"Aeroelastic Response of Variable-Speed Stall-Controlled Wind Turbine Rotors","authors":"Sarah Jalal, F. Ponta, Apurva Baruah","doi":"10.1115/es2019-3803","DOIUrl":"https://doi.org/10.1115/es2019-3803","url":null,"abstract":"\u0000 In this paper, we focus on the Variable-Speed (VS) stall control method, a relatively new idea, which offers a promising perspective for future applications. As with the classical Fixed-Speed (FS) stall method, the elimination of the pitch mechanism, lowers the capital cost and reduces maintenance expenses, while at the same time, allows for a more efficient and precise control of power production. We present an analysis focused on the aeroe-lastic dynamic response of wind turbine rotors operating on the Variable-Speed stall control method. We conducted a wide range of experiments to assess the effects of rapid variations on the rotor’s operational conditions, like sudden gusts. Various gust conditions were tested for different wind speeds, represented by pulses of different intensity, occurring suddenly in an otherwise constant wind regime. Results for the aeroelastic dynamics of the rotor’s response, and the frequency content of its vibrations, are reported and analyzed.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121527043","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. Yellowhair, Kenneth Armijo, Jesus D. Ortega, Jim Clair
Various ganged heliostat concepts have been proposed in the past. The attractive aspect of ganged heliostat concepts is multiple heliostats are grouped so that pedestals, tracking drives, and other components can be shared, thus reducing the number of components. The reduction in the number of components is thought to significantly reduce cost. However, since the drives and tracking mechanisms are shared, accurate on-sun tracking of grouped heliostats becomes challenging because the angular degrees-of-freedom are now limited for the multiple number of combined heliostats. In this paper, the preliminary evaluation of the on-sun tracking of a novel tensile-based cable suspended ganged heliostat concept is provided. In this concept, multiple heliostats are attached to two guide cables. The cables are attached to rotation spreader arms which are anchored to end posts on two ends. The guide cables form a catenary which makes tracking on-sun interesting and challenging. Tracking is performed by rotating the end plates that the two cables are attached to and rotating the individual heliostats in one axis. An additional degree-of-freedom can be added by differentially tensioning the two cables, but this may be challenging to do in practice. Manual on-sun tracking was demonstrated on small-scale prototypes. The rotation arms were coarsely controlled with linear actuators, and the individual heliostats were hand-adjusted in local pitch angle and locked in place with set screws. The coarse angle adjustments showed the tracking accuracy was 3–4 milli-radians. However, with better angle control mechanisms the tracking accuracy can be drastically improved. In this paper, we provide tracking data that was collected for a day, which showed feasibility for automated on-sun tracking. The next steps are to implement better angle control mechanisms and develop tracking algorithms so that the ganged heliostats can automatically track.
{"title":"On-Sun Tracking Evaluation of a Small-Scale Tensile Ganged Heliostat Prototype","authors":"J. Yellowhair, Kenneth Armijo, Jesus D. Ortega, Jim Clair","doi":"10.1115/es2019-3935","DOIUrl":"https://doi.org/10.1115/es2019-3935","url":null,"abstract":"\u0000 Various ganged heliostat concepts have been proposed in the past. The attractive aspect of ganged heliostat concepts is multiple heliostats are grouped so that pedestals, tracking drives, and other components can be shared, thus reducing the number of components. The reduction in the number of components is thought to significantly reduce cost. However, since the drives and tracking mechanisms are shared, accurate on-sun tracking of grouped heliostats becomes challenging because the angular degrees-of-freedom are now limited for the multiple number of combined heliostats. In this paper, the preliminary evaluation of the on-sun tracking of a novel tensile-based cable suspended ganged heliostat concept is provided. In this concept, multiple heliostats are attached to two guide cables. The cables are attached to rotation spreader arms which are anchored to end posts on two ends. The guide cables form a catenary which makes tracking on-sun interesting and challenging. Tracking is performed by rotating the end plates that the two cables are attached to and rotating the individual heliostats in one axis. An additional degree-of-freedom can be added by differentially tensioning the two cables, but this may be challenging to do in practice. Manual on-sun tracking was demonstrated on small-scale prototypes. The rotation arms were coarsely controlled with linear actuators, and the individual heliostats were hand-adjusted in local pitch angle and locked in place with set screws. The coarse angle adjustments showed the tracking accuracy was 3–4 milli-radians. However, with better angle control mechanisms the tracking accuracy can be drastically improved. In this paper, we provide tracking data that was collected for a day, which showed feasibility for automated on-sun tracking. The next steps are to implement better angle control mechanisms and develop tracking algorithms so that the ganged heliostats can automatically track.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125990680","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}
Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. The device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler (TAC). The main components of a typical TA device are a resonator, a regenerator (stack of parallel plates) and two heat exchangers. The thermoacoustic phenomenon takes place in the stack when a nonzero temperature gradient imposed along the regenerator (i.e. parallel to the direction of the sound wave propagation) interacts with the sound wave oscillations. The low temperature at the cold of TAC can be used to condense humid water from the air and also reduce the moisture in the air at some humid areas. In the current study, the high intensity sound waves was produced by the speaker to drive a TA cooler to produce cooling power at a cold temperature of around 18°C. The drainage of condensate in the regenerator is the key for the system performance, because if the porous structure will be blocked by the condensate, TA phenomenon cannot take place in the regenerator. This work is dedicated to investigate the effect from temperature gradient created in TAC for condensation enhancement. 3D printer was used to design and fabricate different structures of regenerator, and then the systematic cooling capacity was measured and compared with different designs of regenerators. Energy balance was also discussed for each type of regenerator. The potential application of this investigation can be an autonomous thermoacoustic cooler system for water harvesting in arid areas. This work can be used to evaluate how the TA effect can be affected by the condensation if humid air is used as the working fluid.
{"title":"Experimental Study of Condensation in Different 3D Printed Regenerators in a Thermoacoustic Cooler","authors":"Aibek Bekkulov, Andrew Luthen, Ben Xu","doi":"10.1115/es2019-3937","DOIUrl":"https://doi.org/10.1115/es2019-3937","url":null,"abstract":"\u0000 Thermoacoustics (TA) deals with the conversion of heat into sound and vice versa. The device that transfers energy from a low temperature reservoir to a high temperature one by utilizing acoustic work is called TA cooler (TAC). The main components of a typical TA device are a resonator, a regenerator (stack of parallel plates) and two heat exchangers. The thermoacoustic phenomenon takes place in the stack when a nonzero temperature gradient imposed along the regenerator (i.e. parallel to the direction of the sound wave propagation) interacts with the sound wave oscillations. The low temperature at the cold of TAC can be used to condense humid water from the air and also reduce the moisture in the air at some humid areas.\u0000 In the current study, the high intensity sound waves was produced by the speaker to drive a TA cooler to produce cooling power at a cold temperature of around 18°C. The drainage of condensate in the regenerator is the key for the system performance, because if the porous structure will be blocked by the condensate, TA phenomenon cannot take place in the regenerator. This work is dedicated to investigate the effect from temperature gradient created in TAC for condensation enhancement. 3D printer was used to design and fabricate different structures of regenerator, and then the systematic cooling capacity was measured and compared with different designs of regenerators. Energy balance was also discussed for each type of regenerator. The potential application of this investigation can be an autonomous thermoacoustic cooler system for water harvesting in arid areas. This work can be used to evaluate how the TA effect can be affected by the condensation if humid air is used as the working fluid.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125601351","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}
Falling particle receivers (FPRs) are an important component of future falling particle concentrating solar power plants to enable next-generation energy generation. High thermal efficiencies in a FPR are required to high thermodynamic efficiencies of the system. External winds can significantly impact the thermal performance of cavity-type FPRs primarily through changing the air flow in and out of the aperture. A numerical parametric study is performed in this paper to quantify the effect of wind on the thermal performance of a FPR. Wind direction was found to be a significant parameter that can affect the receiver thermal efficiency. The particle mass flow rate did not significantly change the overall effect of wind on the receiver. The receiver efficiency was strong function of the particle diameter, but this was primarily a result of varying curtain opacity with different diameters and not from varying effects with wind. Finally, the model was used to demonstrate that receiver efficiencies of 90% were achievable under the assumption that the effect of wind/advective losses were mitigated.
{"title":"Modeling the Thermal Performance of Falling Particle Receivers Subject to External Wind","authors":"Brantley Mills, Reid Shaeffer, C. Ho, L. Yue","doi":"10.1115/es2019-3913","DOIUrl":"https://doi.org/10.1115/es2019-3913","url":null,"abstract":"\u0000 Falling particle receivers (FPRs) are an important component of future falling particle concentrating solar power plants to enable next-generation energy generation. High thermal efficiencies in a FPR are required to high thermodynamic efficiencies of the system. External winds can significantly impact the thermal performance of cavity-type FPRs primarily through changing the air flow in and out of the aperture. A numerical parametric study is performed in this paper to quantify the effect of wind on the thermal performance of a FPR. Wind direction was found to be a significant parameter that can affect the receiver thermal efficiency. The particle mass flow rate did not significantly change the overall effect of wind on the receiver. The receiver efficiency was strong function of the particle diameter, but this was primarily a result of varying curtain opacity with different diameters and not from varying effects with wind. Finally, the model was used to demonstrate that receiver efficiencies of 90% were achievable under the assumption that the effect of wind/advective losses were mitigated.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123816756","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}
Dorsa Ziaei, Seyyed Pooya Hekmati Athar, N. Goudarzi
Computational fluid dynamics (CFD) simulation is usually a computationally expensive, memory demanding, and time consuming iterative process. These drawbacks limit the use of CFD, especially when either spatiotemporal scales or geometry complexity increases. This paper presents the preliminary results from the assessment of an approximation model for predicting non-uniform steady turbulent flows in a 3D domain, utilizing deep learning (DL) algorithms. In particular, the artificial neural network (ANN) approach uses most important variables data from currently CFD simulation results to link multi-variable input spaces (e.g. input speed and direction, geometry configuration) with multi-variable output space (e.g. velocity magnitude, pressure gradient) to obtain an efficient and accurate approximation of the entire velocity field for given input flow field characteristics. The results demonstrated higher computational speed with a similar accuracy using DL algorithms versus CFD simulation. This integrated approach can provide immediate feedback for real-time design iterations for the entire computational domain at the early stages of design. Hence, designers and engineers can easily generate immense amounts of design alternatives without facing the time-consuming task of evaluation and selection.
{"title":"Assessment of a CFD-Based Machine Learning Approach on Turbulent Flow Approximation","authors":"Dorsa Ziaei, Seyyed Pooya Hekmati Athar, N. Goudarzi","doi":"10.1115/es2019-3925","DOIUrl":"https://doi.org/10.1115/es2019-3925","url":null,"abstract":"\u0000 Computational fluid dynamics (CFD) simulation is usually a computationally expensive, memory demanding, and time consuming iterative process. These drawbacks limit the use of CFD, especially when either spatiotemporal scales or geometry complexity increases. This paper presents the preliminary results from the assessment of an approximation model for predicting non-uniform steady turbulent flows in a 3D domain, utilizing deep learning (DL) algorithms. In particular, the artificial neural network (ANN) approach uses most important variables data from currently CFD simulation results to link multi-variable input spaces (e.g. input speed and direction, geometry configuration) with multi-variable output space (e.g. velocity magnitude, pressure gradient) to obtain an efficient and accurate approximation of the entire velocity field for given input flow field characteristics. The results demonstrated higher computational speed with a similar accuracy using DL algorithms versus CFD simulation. This integrated approach can provide immediate feedback for real-time design iterations for the entire computational domain at the early stages of design. Hence, designers and engineers can easily generate immense amounts of design alternatives without facing the time-consuming task of evaluation and selection.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121935195","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 volume of industrial wastewater is expected to double by 2025 resulting in an increase of contaminated freshwater resources. Comparing profits with the high contribution to environment strain per capita can serve to analyze the potential international market and pollutant reduction methods. This paper quantifies the process, water consumption, and pollution of the leather industry to assess its size and influence. The leather industry presents a unique case; one where its product is inherently strong, has multiple applications, and serves as a way of recycling for the meat industry. The wastewater of the leather industry includes Chromium and Nitrogen which are some of the most important concerns regarding the environmental pollution to water sources. The consumption for tanneries varies based on processing methods. Legislative pressure is applied to increase the management of wastewater and solid waste. Research regarding the leather industry is not as well developed as its dated tanning process, however it should be examined as an industry that provides ample opportunities for environmental, economic, and technological advancements.
{"title":"Water Pollution Caused by Leather Industry: A Review","authors":"Magdeline Hutton, Maryam Shafahi","doi":"10.1115/es2019-3949","DOIUrl":"https://doi.org/10.1115/es2019-3949","url":null,"abstract":"\u0000 The volume of industrial wastewater is expected to double by 2025 resulting in an increase of contaminated freshwater resources. Comparing profits with the high contribution to environment strain per capita can serve to analyze the potential international market and pollutant reduction methods. This paper quantifies the process, water consumption, and pollution of the leather industry to assess its size and influence. The leather industry presents a unique case; one where its product is inherently strong, has multiple applications, and serves as a way of recycling for the meat industry. The wastewater of the leather industry includes Chromium and Nitrogen which are some of the most important concerns regarding the environmental pollution to water sources. The consumption for tanneries varies based on processing methods. Legislative pressure is applied to increase the management of wastewater and solid waste. Research regarding the leather industry is not as well developed as its dated tanning process, however it should be examined as an industry that provides ample opportunities for environmental, economic, and technological advancements.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"87 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121279948","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}
Recent studies have shown that the emissions from conventional torrefaction processes is the second largest contributor to the supply chain. This article presents a torrefaction unit that operates based on oxy-combustion concept, whereby preventing carbon dioxide and nitrogen oxides emissions. The oxygen required in the process is supplied from an Air Separation Unit (ASU) and the working fluid of the new system is carbon dioxide. The process model is implemented in Engineering Equation Solver (EES) and simulation is conducted using the design data of a conventional plant which torrefies wood at 553 K for 17.5 minutes. The overall efficiency of the plant which accounts for both thermal and electrical energy requirement of the process is found to be 88%. The total energy consumption of the system exhibits a minimum at an optimum torrefaction temperature. With willow as the feedstock, the optimum temperature is determined to be 536 K at a residence time of 20 minutes, at which the total equivalent thermal energy required is 2 MJ/kg dry biomass and the energy yield is as high as 91%. The results show that the optimum torrefaction temperature is feedstock dependent and it is lower for a longer residence time.
{"title":"Optimization of a Biomass Torrefaction Plant With Near Zero Emissions","authors":"M. Hasan, Y. Haseli","doi":"10.1115/es2019-3963","DOIUrl":"https://doi.org/10.1115/es2019-3963","url":null,"abstract":"\u0000 Recent studies have shown that the emissions from conventional torrefaction processes is the second largest contributor to the supply chain. This article presents a torrefaction unit that operates based on oxy-combustion concept, whereby preventing carbon dioxide and nitrogen oxides emissions. The oxygen required in the process is supplied from an Air Separation Unit (ASU) and the working fluid of the new system is carbon dioxide. The process model is implemented in Engineering Equation Solver (EES) and simulation is conducted using the design data of a conventional plant which torrefies wood at 553 K for 17.5 minutes. The overall efficiency of the plant which accounts for both thermal and electrical energy requirement of the process is found to be 88%. The total energy consumption of the system exhibits a minimum at an optimum torrefaction temperature. With willow as the feedstock, the optimum temperature is determined to be 536 K at a residence time of 20 minutes, at which the total equivalent thermal energy required is 2 MJ/kg dry biomass and the energy yield is as high as 91%. The results show that the optimum torrefaction temperature is feedstock dependent and it is lower for a longer residence time.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130419421","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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