Solar water heating (SWH) systems are the most common application of renewable energy technology that converts solar radiation into useful energy for domestic/industrial activities. The novelty of this study is the design of a new SWH that combines the heat transfer and storage both in a single unit. The selected type of collector for this purpose is an evacuated tube solar collector (ETC). The new design of the ETC has been developed by applying a U-tube inside the collector which contains the heat transfer fluid (HTF). The HTF flows into an external heat exchanger that transfers heat to the water. The implementation of sugar alcohol namely Erythritol (C4H10O4) as the HTF for moderate operating temperature applications was investigated. Moreover, the utilization of solid-liquid phase change material, Tritriacontane paraffin (C33H68), inside the ETC, allows direct heat storage on the system and delayed release of heat. A computational fluid dynamics (CFD) modeling of a single U-tube ETC is performed using ANSYS Fluent in stagnation (on-demand) operation. A 3D model of the ETC is developed and the appropriate boundary conditions are applied. Moreover, the thermal performance comparison of U-tube vs heat pipe ETC has been done. The results from this study shows the maximum fin temperature difference of 46°C of U-tube ETC compared with heat pipe ETC.
{"title":"Thermal Performance Analysis of a Novel U-Tube Evacuated Tube Solar Collector","authors":"C. Lim, Vivek R. Pawar, Sarvenaz Sobhansarbandi","doi":"10.1115/es2020-1674","DOIUrl":"https://doi.org/10.1115/es2020-1674","url":null,"abstract":"\u0000 Solar water heating (SWH) systems are the most common application of renewable energy technology that converts solar radiation into useful energy for domestic/industrial activities. The novelty of this study is the design of a new SWH that combines the heat transfer and storage both in a single unit. The selected type of collector for this purpose is an evacuated tube solar collector (ETC). The new design of the ETC has been developed by applying a U-tube inside the collector which contains the heat transfer fluid (HTF). The HTF flows into an external heat exchanger that transfers heat to the water. The implementation of sugar alcohol namely Erythritol (C4H10O4) as the HTF for moderate operating temperature applications was investigated. Moreover, the utilization of solid-liquid phase change material, Tritriacontane paraffin (C33H68), inside the ETC, allows direct heat storage on the system and delayed release of heat. A computational fluid dynamics (CFD) modeling of a single U-tube ETC is performed using ANSYS Fluent in stagnation (on-demand) operation. A 3D model of the ETC is developed and the appropriate boundary conditions are applied. Moreover, the thermal performance comparison of U-tube vs heat pipe ETC has been done. The results from this study shows the maximum fin temperature difference of 46°C of U-tube ETC compared with heat pipe ETC.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84891418","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}
Despite many efforts and improvements over the last few decades, two of the major challenges facing Solid Oxide Fuel Cells (SOFCs) are slow heating rates to operating conditions (typically < 5 °C.min−1) and a limited ability to thermal cycle (< 200 cycles). Recently a novel hybridized setup that combines a fuel-rich combustion reformer with a SOFC was developed and utilized to investigate rapid heating, cooling and thermal cycling of a micro-Tubular SOFC. The setup places the SOFC directly in the flame and exhaust of the high temperature combustion of methane, which allows for extremely rapid temperature rise in the SOFC. A SOFC with a (La0.8Sr0.2)0.95MnO3-x cathode was tested in the setup, but limitations on air preheating for the cathode resulted in low SOFC cathode temperatures (∼500°C) and low power density. Thermal insulation improved pre-heating of the air delivered to the cathode, increased the SOFC cathode temperature and, when a (La0.60Sr0.40)0.95Co0.20Fe0.80O3-x cathode was applied to the SOFC, resulted in improved power density. After adjusting the thermal insulation, the air temperature near the cathode exceeded ∼750°C during testing. Over 3,000 thermal cycles were conducted at a heating rate exceeding 900°C.min−1 and a cooling rate that exceeded 300°C.min−1. The open circuit voltage was analyzed over the 150 h test and a low degradation rate of ∼0.0008V per 100 cycles per fuel cell was observed. Unlike the previous test, which was conducted at lower temperatures, significant degradation of the current collector was observed during this test. Electrochemical impedance spectroscopy shows that degradation in the SOFC was due to increases in ohmic losses, activation losses at the cathode and increased concentration losses. The setup demonstrates that rapid thermal cycling of micro-Tubular SOFCs can be achieved, but there are limitations on the maximum temperature that can be sustained depending on the current collector.
{"title":"Investigation of Temperature Limitations During Rapid Thermal Cycling of a Micro-Tubular Flame-Assisted Fuel Cell","authors":"R. Milcarek, R. Ghotkar, J. Ahn","doi":"10.1115/es2020-1634","DOIUrl":"https://doi.org/10.1115/es2020-1634","url":null,"abstract":"\u0000 Despite many efforts and improvements over the last few decades, two of the major challenges facing Solid Oxide Fuel Cells (SOFCs) are slow heating rates to operating conditions (typically < 5 °C.min−1) and a limited ability to thermal cycle (< 200 cycles). Recently a novel hybridized setup that combines a fuel-rich combustion reformer with a SOFC was developed and utilized to investigate rapid heating, cooling and thermal cycling of a micro-Tubular SOFC. The setup places the SOFC directly in the flame and exhaust of the high temperature combustion of methane, which allows for extremely rapid temperature rise in the SOFC. A SOFC with a (La0.8Sr0.2)0.95MnO3-x cathode was tested in the setup, but limitations on air preheating for the cathode resulted in low SOFC cathode temperatures (∼500°C) and low power density. Thermal insulation improved pre-heating of the air delivered to the cathode, increased the SOFC cathode temperature and, when a (La0.60Sr0.40)0.95Co0.20Fe0.80O3-x cathode was applied to the SOFC, resulted in improved power density. After adjusting the thermal insulation, the air temperature near the cathode exceeded ∼750°C during testing. Over 3,000 thermal cycles were conducted at a heating rate exceeding 900°C.min−1 and a cooling rate that exceeded 300°C.min−1. The open circuit voltage was analyzed over the 150 h test and a low degradation rate of ∼0.0008V per 100 cycles per fuel cell was observed. Unlike the previous test, which was conducted at lower temperatures, significant degradation of the current collector was observed during this test. Electrochemical impedance spectroscopy shows that degradation in the SOFC was due to increases in ohmic losses, activation losses at the cathode and increased concentration losses. The setup demonstrates that rapid thermal cycling of micro-Tubular SOFCs can be achieved, but there are limitations on the maximum temperature that can be sustained depending on the current collector.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86850626","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}
Jeffrey James C. Laguitao, E. Quiros, Jose Gabriel E. Mercado, Paul Rodgers
This paper presents a study on the effects of transient and steady-state vehicle operation on fuel economy and emissions trends of an in-use Euro 2 Asian utility vehicle in the Philippines, with a normally aspirated direct-injection engine, and fueled with different CME-diesel blends designated as B1, B2, B3, B5, B10, B20, B50, & B100 corresponding to increasing CME percentage blends. The vehicle was driven on a chassis dynamometer following the Japanese 10-15 Mode drive cycle and at steady speeds of 40, 60, & 80 kph for fuel consumption and CO, NOx, and THC measurements. PM measurements were not undertaken. Drive cycle results showed that adding CME up to 20% by volume (B20) has a small effect on the heating values, specific fuel consumption (SFC), fuel economy (FE), and maximum power. Relative to neat diesel, the increase in SFC, lower FE and power beyond B20 were attributed to lower heating values at higher blends. CO was practically constant while THC and NOx generally decreased with increasing CME blends. The CO and THC trends were ascribed to overall lean mixtures and increased amount of oxygenated fuel at higher CME blends. B20 yielded the most emissions reduction without performance loss. Steady speed results indicated for all blends, SFC increased with vehicle speed due to higher road load. Above B10, SFC went beyond 5% higher than that for neat diesel and is attributed to lowered heating values of higher blends. The SFC of blends up to B10 approached that of neat diesel as speed increased suggesting more diesel-like combustion characteristics. The blend fuel economy showed an inverse relationship to SFC as expected. Both CO and NOx exhibited slightly decreasing trends with higher blends at all speeds. For a given blend, CO decreased while NOx increased as speed went higher. THC followed bowl-shaped trendlines with blend ratio. THC was high for neat diesel going lowest at B5-B10 and upwards again beyond B10. For a given blend, THC emissions decreased with increasing vehicle speed.
{"title":"Fuel Economy and Emissions of Philippine CME-Diesel Blends From Drive Cycle and Steady Speed Operation","authors":"Jeffrey James C. Laguitao, E. Quiros, Jose Gabriel E. Mercado, Paul Rodgers","doi":"10.1115/es2020-1627","DOIUrl":"https://doi.org/10.1115/es2020-1627","url":null,"abstract":"\u0000 This paper presents a study on the effects of transient and steady-state vehicle operation on fuel economy and emissions trends of an in-use Euro 2 Asian utility vehicle in the Philippines, with a normally aspirated direct-injection engine, and fueled with different CME-diesel blends designated as B1, B2, B3, B5, B10, B20, B50, & B100 corresponding to increasing CME percentage blends. The vehicle was driven on a chassis dynamometer following the Japanese 10-15 Mode drive cycle and at steady speeds of 40, 60, & 80 kph for fuel consumption and CO, NOx, and THC measurements. PM measurements were not undertaken.\u0000 Drive cycle results showed that adding CME up to 20% by volume (B20) has a small effect on the heating values, specific fuel consumption (SFC), fuel economy (FE), and maximum power. Relative to neat diesel, the increase in SFC, lower FE and power beyond B20 were attributed to lower heating values at higher blends. CO was practically constant while THC and NOx generally decreased with increasing CME blends. The CO and THC trends were ascribed to overall lean mixtures and increased amount of oxygenated fuel at higher CME blends. B20 yielded the most emissions reduction without performance loss.\u0000 Steady speed results indicated for all blends, SFC increased with vehicle speed due to higher road load. Above B10, SFC went beyond 5% higher than that for neat diesel and is attributed to lowered heating values of higher blends. The SFC of blends up to B10 approached that of neat diesel as speed increased suggesting more diesel-like combustion characteristics. The blend fuel economy showed an inverse relationship to SFC as expected. Both CO and NOx exhibited slightly decreasing trends with higher blends at all speeds. For a given blend, CO decreased while NOx increased as speed went higher. THC followed bowl-shaped trendlines with blend ratio. THC was high for neat diesel going lowest at B5-B10 and upwards again beyond B10. For a given blend, THC emissions decreased with increasing vehicle speed.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79265039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Munir, S. Hussain, Ali Al-Alili, Reem Al Ameri, Ehab El-Sadaany
One of the core features of the smart grid deemed essential for smooth grid operation is the detection and diagnosis of system failures. For a utility transmission grid system, these failures could manifest in the form of short circuit faults and open circuit faults. Due to the advent of the digital age, the traditional grid has also undergone a massive transition to digital equipment and modern sensors which are capable of generating large volumes of data. The challenge is to preprocess this data such that it can be utilized for the detection of transients and grid failures. This paper presents the incorporation of artificial intelligence techniques such as Support Vector Machine (SVM) and K-Nearest Neighbors (KNN) to detect and comprehensively classify the most common fault transients within a reasonable range of accuracy. For gauging the effectiveness of the proposed scheme, a thorough evaluation study is conducted on a modified IEEE-39 bus system. Bus voltage and line current measurements are taken for a range of fault scenarios which result in high-frequency transient signals. These signals are analyzed using continuous wavelet transform (CWT). The measured signals are afterward preprocessed using Discrete Wavelet Transform (DWT) employing Daubechies four (Db4) mother wavelet in order to decompose the high-frequency components of the faulty signals. DWT results in a range of high and low-frequency detail and approximate coefficients, from which a range of statistical features are extracted and used as inputs for training and testing the classification algorithms. The results demonstrate that the trained models can be successfully employed to detect and classify faults on the transmission system with acceptable accuracy.
{"title":"Fault Detection and Classification in Smart Grids Using Wavelet Analysis","authors":"M. Munir, S. Hussain, Ali Al-Alili, Reem Al Ameri, Ehab El-Sadaany","doi":"10.1115/es2020-1641","DOIUrl":"https://doi.org/10.1115/es2020-1641","url":null,"abstract":"\u0000 One of the core features of the smart grid deemed essential for smooth grid operation is the detection and diagnosis of system failures. For a utility transmission grid system, these failures could manifest in the form of short circuit faults and open circuit faults. Due to the advent of the digital age, the traditional grid has also undergone a massive transition to digital equipment and modern sensors which are capable of generating large volumes of data. The challenge is to preprocess this data such that it can be utilized for the detection of transients and grid failures. This paper presents the incorporation of artificial intelligence techniques such as Support Vector Machine (SVM) and K-Nearest Neighbors (KNN) to detect and comprehensively classify the most common fault transients within a reasonable range of accuracy. For gauging the effectiveness of the proposed scheme, a thorough evaluation study is conducted on a modified IEEE-39 bus system. Bus voltage and line current measurements are taken for a range of fault scenarios which result in high-frequency transient signals. These signals are analyzed using continuous wavelet transform (CWT). The measured signals are afterward preprocessed using Discrete Wavelet Transform (DWT) employing Daubechies four (Db4) mother wavelet in order to decompose the high-frequency components of the faulty signals. DWT results in a range of high and low-frequency detail and approximate coefficients, from which a range of statistical features are extracted and used as inputs for training and testing the classification algorithms. The results demonstrate that the trained models can be successfully employed to detect and classify faults on the transmission system with acceptable accuracy.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90997839","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}
Rupert Karlo D. Aguila, E. Quiros, Jose Gabriel E. Mercado
For the past years, Different Philippine local regulations have been imposed to address oil importation and to address environment concerns. One requirement is reduced emission from diesel engines and at the same time reduce the use of fossil fuels for the. In accordance to the Clean Air Act and the Biofuels Act, The Philippine government is looking for possible alternatives to fossil fuels, One of the biodiesel the country is currently using is coconut methyl ester due to the abundance of coconut trees in the country. This research shows the performance and emission characteristics of diesel blended with coconut methyl ester in a CRDi Passenger van and will help the government justify the increase in blend percentage mandated in commercial fuels. This study is investigates 0%, 2%, 5% 10% and 20% Coconut Methyl Ester (CME)-diesel blends. The experiment consisted of Japanese 10-15 standard drive cycle test, steady state test at 40,60, & 80 kph was performed in the Vehicle Research and Testing Laboratory in the University of the Philippines Diliman equipped with chassis dynamometer, fuel flow meter and emissions analyzer. Performance parameters measured are Power, Specific Fuel Consumption and Mileage, while emission characteristics for CO, NOx, THC are measured. PM measurements were not measured for this experiment. In both Drive cycle and steady state test specific fuel consumption and mileage improved with addition of CME, however results showed they are independent of CME percentage. The best improvement was observed with 5%CME blended with neat diesel at 4.8% and 8.5% for drive cycle and steady state test respectively. Majority of the CME-diesel blends showed decrease in emission specifically in CO and THC emission which is consistent to published literature. For both steady state test and drive cycle test up to 29.5% decrease inn CO and up to 64% decrease in THC was observed. This can be attributed to the overall lean mixtures and in the increase of oxygenated fuel at higher CME blends. NOx emission however is consistent for all fuel blends in the drive cycle test while for the steady state test NOx emission is dependnt on the engine speed. Decreasing trend was obtained for 40 and 60 km/h while increasing trend was obtrained at 80 km/h, with respect to %CME. Average power produced for all the speeds was basically constant for all the blends as compared with neat diesel. Lastly, maximum power showed insignificant changes although majority of the blends showed a minimal power reduction as compared to neat diesel.
{"title":"Investigation of Performance and Emissions of a CRDI Passenger Van Fuelled With Coconut Methyl Ester-Diesel Blends Using Drive Cycle and Steady Speed Operation","authors":"Rupert Karlo D. Aguila, E. Quiros, Jose Gabriel E. Mercado","doi":"10.1115/es2020-1708","DOIUrl":"https://doi.org/10.1115/es2020-1708","url":null,"abstract":"\u0000 For the past years, Different Philippine local regulations have been imposed to address oil importation and to address environment concerns. One requirement is reduced emission from diesel engines and at the same time reduce the use of fossil fuels for the. In accordance to the Clean Air Act and the Biofuels Act, The Philippine government is looking for possible alternatives to fossil fuels, One of the biodiesel the country is currently using is coconut methyl ester due to the abundance of coconut trees in the country. This research shows the performance and emission characteristics of diesel blended with coconut methyl ester in a CRDi Passenger van and will help the government justify the increase in blend percentage mandated in commercial fuels.\u0000 This study is investigates 0%, 2%, 5% 10% and 20% Coconut Methyl Ester (CME)-diesel blends. The experiment consisted of Japanese 10-15 standard drive cycle test, steady state test at 40,60, & 80 kph was performed in the Vehicle Research and Testing Laboratory in the University of the Philippines Diliman equipped with chassis dynamometer, fuel flow meter and emissions analyzer. Performance parameters measured are Power, Specific Fuel Consumption and Mileage, while emission characteristics for CO, NOx, THC are measured. PM measurements were not measured for this experiment.\u0000 In both Drive cycle and steady state test specific fuel consumption and mileage improved with addition of CME, however results showed they are independent of CME percentage. The best improvement was observed with 5%CME blended with neat diesel at 4.8% and 8.5% for drive cycle and steady state test respectively.\u0000 Majority of the CME-diesel blends showed decrease in emission specifically in CO and THC emission which is consistent to published literature. For both steady state test and drive cycle test up to 29.5% decrease inn CO and up to 64% decrease in THC was observed. This can be attributed to the overall lean mixtures and in the increase of oxygenated fuel at higher CME blends. NOx emission however is consistent for all fuel blends in the drive cycle test while for the steady state test NOx emission is dependnt on the engine speed. Decreasing trend was obtained for 40 and 60 km/h while increasing trend was obtrained at 80 km/h, with respect to %CME.\u0000 Average power produced for all the speeds was basically constant for all the blends as compared with neat diesel. Lastly, maximum power showed insignificant changes although majority of the blends showed a minimal power reduction as compared to neat diesel.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82286965","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}
Realizing cost-effective, dispatchable, renewable energy production using concentrated solar power (CSP) relies on reaching high process temperatures to increase the thermal-to-electrical efficiency. Ceramic based particles used as both the energy storage medium and heat transfer fluid is a promising approach to increasing the operating temperature of next generation CSP plants. The particle-to-supercritical CO2 (sCO2) heat exchanger is a critical component in the development of this technology for transferring thermal energy from the heated ceramic particles to the sCO2 working fluid of the power cycle. The leading design for the particle-to-sCO2 heat exchanger is a shell-and-plate configuration. Currently, design work is focused on optimizing the performance of the heat exchanger through reducing the plate spacing. However, the particle channel geometry is limited by uniformity and reliability of particle flow in narrow vertical channels. Results of high temperature experimental particle flow testing are presented in this paper.
{"title":"High-Temperature Particle Flow Testing in Parallel Plates for Particle-to-Supercritical CO2 Heat Exchanger Applications","authors":"H. Laubscher, Kevin Albrecht, C. Ho","doi":"10.1115/es2020-1664","DOIUrl":"https://doi.org/10.1115/es2020-1664","url":null,"abstract":"\u0000 Realizing cost-effective, dispatchable, renewable energy production using concentrated solar power (CSP) relies on reaching high process temperatures to increase the thermal-to-electrical efficiency. Ceramic based particles used as both the energy storage medium and heat transfer fluid is a promising approach to increasing the operating temperature of next generation CSP plants. The particle-to-supercritical CO2 (sCO2) heat exchanger is a critical component in the development of this technology for transferring thermal energy from the heated ceramic particles to the sCO2 working fluid of the power cycle. The leading design for the particle-to-sCO2 heat exchanger is a shell-and-plate configuration. Currently, design work is focused on optimizing the performance of the heat exchanger through reducing the plate spacing. However, the particle channel geometry is limited by uniformity and reliability of particle flow in narrow vertical channels. Results of high temperature experimental particle flow testing are presented in this paper.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83979209","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}
E. Ebrahimnia-Bajestan, M. Arjmand, Hani Tiznobaik
During the operation of a power transformer, a large amount of heat is generated due to the electrical and magnetic energy losses in its core and windings, causing a temperature rise in transformers. This generated heat is known as the main factor for aging the electrical insulating system of a transformer. In this research, we numerically studied the ability of a vegetable-based oil — as an alternative coolant for the petroleum-based oils — on the cooling performance of a power transformer. The studied oil was a biodiesel produced from waste cooking vegetable oils, having lower viscosity compared to traditional mineral oils. We also calculated the aging rate of the transformer in the presence of the biodiesel. The results indicated that compared to the mineral oil, the average hotspot temperature of the transformer is 3 degrees lower when the biodiesel was used. The life expectancy of the transformer with the vegetable-based oil was also significantly longer than the case with mineral oil. In conclusion, this study provided a sustainable way to use an eco-friendly material produced from a waste resource as an alternative insulating liquid for the cooling of power transformers.
{"title":"Effect of Waste Vegetable Oil on Cooling Performance and Lifetime of Power Transformers","authors":"E. Ebrahimnia-Bajestan, M. Arjmand, Hani Tiznobaik","doi":"10.1115/es2020-1716","DOIUrl":"https://doi.org/10.1115/es2020-1716","url":null,"abstract":"\u0000 During the operation of a power transformer, a large amount of heat is generated due to the electrical and magnetic energy losses in its core and windings, causing a temperature rise in transformers. This generated heat is known as the main factor for aging the electrical insulating system of a transformer. In this research, we numerically studied the ability of a vegetable-based oil — as an alternative coolant for the petroleum-based oils — on the cooling performance of a power transformer. The studied oil was a biodiesel produced from waste cooking vegetable oils, having lower viscosity compared to traditional mineral oils. We also calculated the aging rate of the transformer in the presence of the biodiesel. The results indicated that compared to the mineral oil, the average hotspot temperature of the transformer is 3 degrees lower when the biodiesel was used. The life expectancy of the transformer with the vegetable-based oil was also significantly longer than the case with mineral oil. In conclusion, this study provided a sustainable way to use an eco-friendly material produced from a waste resource as an alternative insulating liquid for the cooling of power transformers.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86078012","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 focuses on applications of unmanned aerial vehicles (UAVs) for measuring optical error of heliostats in concentrating solar power (CSP) plants. In CSP, there is a need to measure solar-field optical errors, which is critical for future production improvement as well as for operations and maintenance of a heliostat field. This latter need is particularly challenging because of the large number of heliostats (over 10,000 for a utility-scale power plant) that individually track the sun in the field. To address this issue, a camera-equipped UAV, with an optimized drone flight path developed and uploaded to it, collects images of a precise reflection of the tower on each heliostat to evaluate optical error sources without interrupting plant operation. Generation of the drone path for capturing the reflected images is affected by a number technical and realistic constraints, which include the camera angle used to capture the image, the blocking of the camera view due to surrounding heliostats, the location of the camera in reference to the target heliostat, and the target heliostat position with reference to the tower. The effect of these constraints on calculating the camera position will be discussed in detail in this article. An effective drone-path algorithm is generated to fulfil the need of image collection under various constraints.
{"title":"Unmanned Aerial Vehicle Path Generation for Image Collection to Assist Heliostat Field Optical Characterization","authors":"Kidus Guye, Rebecca Mitchell, G. Zhu","doi":"10.1115/es2020-1683","DOIUrl":"https://doi.org/10.1115/es2020-1683","url":null,"abstract":"\u0000 This paper focuses on applications of unmanned aerial vehicles (UAVs) for measuring optical error of heliostats in concentrating solar power (CSP) plants. In CSP, there is a need to measure solar-field optical errors, which is critical for future production improvement as well as for operations and maintenance of a heliostat field. This latter need is particularly challenging because of the large number of heliostats (over 10,000 for a utility-scale power plant) that individually track the sun in the field. To address this issue, a camera-equipped UAV, with an optimized drone flight path developed and uploaded to it, collects images of a precise reflection of the tower on each heliostat to evaluate optical error sources without interrupting plant operation. Generation of the drone path for capturing the reflected images is affected by a number technical and realistic constraints, which include the camera angle used to capture the image, the blocking of the camera view due to surrounding heliostats, the location of the camera in reference to the target heliostat, and the target heliostat position with reference to the tower. The effect of these constraints on calculating the camera position will be discussed in detail in this article. An effective drone-path algorithm is generated to fulfil the need of image collection under various constraints.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90816322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A significant portion of the infrared solar spectrum is either unused, or wasted by inefficient solar energy conversion. In this paper, we show that infrared light harvesting can also be accomplished by dispersions of polar nanoparticles. Polar nanoparticle dispersions in a selective absorber may result in Solar Thermal Desalination (STD) systems that aim to maximize the solar-to-heat conversion efficiency by managing the thermal radiative and conduction losses. In noting that irregular dispersions of polar nanoparticles are less costly than regularly spaced nanostructures to manufacture at large scales, we describe the solar absorptivity as a function of a nanoparticle chain model determined emissivity and thermal conductance. The near-field interactions between nanoparticles are explained by modeling the nanoparticles as dispersed electromagnetic dipole oscillations that interact with solar light. An FDTD model of polar nanodispersions near an optical cavity is used to demonstrate infrared harvesting. With this model, we show that the infrared light-harvesting mechanisms of silica nanoparticles involve local and propagating surface phonon polaritons and varying the volume fraction changes radiation transport properties by several orders of magnitude. In discussing STD systems, we demonstrate a potential to use nanoparticle chains to create novel selective absorbers with tunable solar absorptivity.
{"title":"Selective Infrared Energy Harvesting by Nanoparticle Dispersions in Solar Thermal Desalination Systems","authors":"J. Hammonds, K. Stancil, O. Adewuyi","doi":"10.1115/es2020-1654","DOIUrl":"https://doi.org/10.1115/es2020-1654","url":null,"abstract":"\u0000 A significant portion of the infrared solar spectrum is either unused, or wasted by inefficient solar energy conversion. In this paper, we show that infrared light harvesting can also be accomplished by dispersions of polar nanoparticles. Polar nanoparticle dispersions in a selective absorber may result in Solar Thermal Desalination (STD) systems that aim to maximize the solar-to-heat conversion efficiency by managing the thermal radiative and conduction losses. In noting that irregular dispersions of polar nanoparticles are less costly than regularly spaced nanostructures to manufacture at large scales, we describe the solar absorptivity as a function of a nanoparticle chain model determined emissivity and thermal conductance. The near-field interactions between nanoparticles are explained by modeling the nanoparticles as dispersed electromagnetic dipole oscillations that interact with solar light. An FDTD model of polar nanodispersions near an optical cavity is used to demonstrate infrared harvesting. With this model, we show that the infrared light-harvesting mechanisms of silica nanoparticles involve local and propagating surface phonon polaritons and varying the volume fraction changes radiation transport properties by several orders of magnitude. In discussing STD systems, we demonstrate a potential to use nanoparticle chains to create novel selective absorbers with tunable solar absorptivity.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85557076","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}
Andrey Gunawan, Bettina K. Arkhurst, Sonja Brankovic, S. Yee
Novel high temperature (≥ 700°C) Heat Transfer Medias (HTMs, e.g., molten salts) and corrosion-resistant Containment Materials (CMs, e.g., metal alloys or ceramics) are necessary for concentrated solar power (CSP) given the emphasis on higher temperatures and high cycle efficiency in the 3rd generation CSP (Gen3 CSP) technologies. In early 2019, we sent out an online survey to the Gen3 CSP community to fully assess the communal needs for thermophysical properties measurements of which HTMs and CMs, and what temperature range and other testing environments would be ideal for those materials. Based on the recorded responses, seven unique HTMs and twenty-six unique CMs were identified. Since then the list has been constantly updated, following our interactions and inputs from the Gen3 CSP community, with some new materials substituting their older counterparts. Currently, there are total of ten unique HTMs and twenty-nine unique CMs that are under consideration by the Gen3 CSP community. By analyzing the available body of research to date and combining it with our survey data from within the Gen3 CSP community, this paper presents trends of what people in the CSP world are thinking regarding materials worth investigating and suggests which thermophysical property measurements are critical to advance high-temperature CSP systems.
{"title":"Gen3 CSP Materials: Critical Review of Limited Existing and New Survey Data","authors":"Andrey Gunawan, Bettina K. Arkhurst, Sonja Brankovic, S. Yee","doi":"10.1115/es2020-1690","DOIUrl":"https://doi.org/10.1115/es2020-1690","url":null,"abstract":"\u0000 Novel high temperature (≥ 700°C) Heat Transfer Medias (HTMs, e.g., molten salts) and corrosion-resistant Containment Materials (CMs, e.g., metal alloys or ceramics) are necessary for concentrated solar power (CSP) given the emphasis on higher temperatures and high cycle efficiency in the 3rd generation CSP (Gen3 CSP) technologies. In early 2019, we sent out an online survey to the Gen3 CSP community to fully assess the communal needs for thermophysical properties measurements of which HTMs and CMs, and what temperature range and other testing environments would be ideal for those materials. Based on the recorded responses, seven unique HTMs and twenty-six unique CMs were identified. Since then the list has been constantly updated, following our interactions and inputs from the Gen3 CSP community, with some new materials substituting their older counterparts. Currently, there are total of ten unique HTMs and twenty-nine unique CMs that are under consideration by the Gen3 CSP community. By analyzing the available body of research to date and combining it with our survey data from within the Gen3 CSP community, this paper presents trends of what people in the CSP world are thinking regarding materials worth investigating and suggests which thermophysical property measurements are critical to advance high-temperature CSP systems.","PeriodicalId":8602,"journal":{"name":"ASME 2020 14th International Conference on Energy Sustainability","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80449869","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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