J. I. Encarnacion, Gavin Lavery, S. Ordoñez-Sanchez, C. Johnstone
Computer simulations aid in the design of any device. However, physical testing is still needed to validate these simulations and problems may arise if fabrication limits are not incorporated. This study was undertaken to quantify the losses in a low-solidity turbine rotor designed for less energetic flow. The blade was tested at a scale of 1m resulting in a blade length of 219mm. A 0.5mm minimum thickness fabrication limit was worked with by shifting all the points of the upper surface of the blade sections by 0.5mm at the 219mm scale introducing a huge distortion in each of the blade sections. Lift and drag characteristics of the distorted aerofoil are obtained via ANSYS Fluent and served as the corrected inputs for the BEM characterisation. It was found that the BEM predicts a reduced performance similar to the physical testing although it still over predicts the performance of the turbine. However, there is an agreement on the trend of the simulated performance and the physical testing in addition to the reduction of the variation between the two. Additional aerofoil alterations are studied to inform on future experimental designs. It was then found that out of the altered cases, shifting the upper surface by the required minimum thickness resulted in the best approximation of the simulated performance. This is far from acceptable as the variation between the ideal computer simulated case is too large to just incorporate corrections. Thus, an analysis is carried out using a 400mm scaled blade, thereby decreasing the distortion on each blade section. The results of the analysis show good agreement with the ideal section and minimal reduction in performance at about 5% less than the ideal.
{"title":"Effects of Trailing Edge Alterations on the Performance of a Small-Scale, Low-Solidity Tidal Turbine Blade Designed for Less Energetic Flows","authors":"J. I. Encarnacion, Gavin Lavery, S. Ordoñez-Sanchez, C. Johnstone","doi":"10.1115/es2019-3891","DOIUrl":"https://doi.org/10.1115/es2019-3891","url":null,"abstract":"\u0000 Computer simulations aid in the design of any device. However, physical testing is still needed to validate these simulations and problems may arise if fabrication limits are not incorporated. This study was undertaken to quantify the losses in a low-solidity turbine rotor designed for less energetic flow. The blade was tested at a scale of 1m resulting in a blade length of 219mm. A 0.5mm minimum thickness fabrication limit was worked with by shifting all the points of the upper surface of the blade sections by 0.5mm at the 219mm scale introducing a huge distortion in each of the blade sections. Lift and drag characteristics of the distorted aerofoil are obtained via ANSYS Fluent and served as the corrected inputs for the BEM characterisation. It was found that the BEM predicts a reduced performance similar to the physical testing although it still over predicts the performance of the turbine. However, there is an agreement on the trend of the simulated performance and the physical testing in addition to the reduction of the variation between the two. Additional aerofoil alterations are studied to inform on future experimental designs. It was then found that out of the altered cases, shifting the upper surface by the required minimum thickness resulted in the best approximation of the simulated performance. This is far from acceptable as the variation between the ideal computer simulated case is too large to just incorporate corrections. Thus, an analysis is carried out using a 400mm scaled blade, thereby decreasing the distortion on each blade section. The results of the analysis show good agreement with the ideal section and minimal reduction in performance at about 5% less than the ideal.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"6 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":"130671995","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 Concentrating solar thermal (CST) system integrated with a high-performance solar receiver can provide high-temperature process heat to drive thermochemical energy storage (TCES) or thermochemical fuel production processes with improved equilibrium conversion and fast reaction rates. An advantage of integrating a CST system with a thermochemical process is the ability to store chemical energy in large quantities for continuous downstream operations. However, a challenge in the effective conversion of solar energy to power or fuels is that high-temperature thermochemical process operating conditions require a high solar concentration ratio for efficient operation which imposes design difficulties for solar energy collection. Integration of the solar collection system with a thermochemical process affects the system efficiency and final product cost due to the relatively high solar field cost. Thus, optimization of the collection system provides a significant opportunity to reduce cost of solar thermochemical power or fuel. In this paper, we present a solar field layout strategy and assess the feasibility of a novel planar-cavity receiver to drive thermochemical processes with reaction temperatures in the range of 500–900°C. The complete solar collection system performance is examined and importance of conducting coupled field/receiver analyses is demonstrated by illustrating how improved spillage control by a modified heliostat aiming strategy impacts system radiative losses downstream. The planar-cavity receiver shows improved performance with increasing concentration ratio and superior performance over a flat plate receiver operating under the same prescribed operating conditions.
{"title":"Analysis of Concentrating Solar Thermal System to Support Thermochemical Energy Storage or Solar Fuel Generation Processes","authors":"P. Davenport, J. Martinek, Zhiwen Ma","doi":"10.1115/es2019-3871","DOIUrl":"https://doi.org/10.1115/es2019-3871","url":null,"abstract":"\u0000 A Concentrating solar thermal (CST) system integrated with a high-performance solar receiver can provide high-temperature process heat to drive thermochemical energy storage (TCES) or thermochemical fuel production processes with improved equilibrium conversion and fast reaction rates. An advantage of integrating a CST system with a thermochemical process is the ability to store chemical energy in large quantities for continuous downstream operations. However, a challenge in the effective conversion of solar energy to power or fuels is that high-temperature thermochemical process operating conditions require a high solar concentration ratio for efficient operation which imposes design difficulties for solar energy collection. Integration of the solar collection system with a thermochemical process affects the system efficiency and final product cost due to the relatively high solar field cost. Thus, optimization of the collection system provides a significant opportunity to reduce cost of solar thermochemical power or fuel. In this paper, we present a solar field layout strategy and assess the feasibility of a novel planar-cavity receiver to drive thermochemical processes with reaction temperatures in the range of 500–900°C. The complete solar collection system performance is examined and importance of conducting coupled field/receiver analyses is demonstrated by illustrating how improved spillage control by a modified heliostat aiming strategy impacts system radiative losses downstream. The planar-cavity receiver shows improved performance with increasing concentration ratio and superior performance over a flat plate receiver operating under the same prescribed operating conditions.","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":"117087401","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 perovskite solar cell in the inverted configuration was modeled and simulated to investigate the impact of the cathode work function on the cell performance. The model utilized the drift-diffusion current equations, coupled with Poisson’s equation and continuity equations to determine the J-V characteristics, the band diagram, and the external quantum efficiencies. It was found the power conversion efficiency (PCE) tended to decrease with the increasing work functions of the metal cathode. The device using low work function metal Ca delivered the best PCE of 16.7%, whereas the one with high work function Au possessed the lowest PCE of 0.3%. These results were in a close agreement with experiments in literature. Photovoltaic parameters (FF, Jsc, and Voc) showed the same tendency and were responsible for the PCE. The band diagram revealed the formation of Schottky barrier was the main reason for the reduction in Voc, and the external quantum efficiency spectrum showed the adverse effect of the Schottky barrier on the charge extraction.
{"title":"Influence of Metal Electrodes on the Charge Extraction of Inverted Perovskite Solar Cells","authors":"J. Gong, S. Krishnan","doi":"10.1115/es2019-3807","DOIUrl":"https://doi.org/10.1115/es2019-3807","url":null,"abstract":"\u0000 A perovskite solar cell in the inverted configuration was modeled and simulated to investigate the impact of the cathode work function on the cell performance. The model utilized the drift-diffusion current equations, coupled with Poisson’s equation and continuity equations to determine the J-V characteristics, the band diagram, and the external quantum efficiencies. It was found the power conversion efficiency (PCE) tended to decrease with the increasing work functions of the metal cathode. The device using low work function metal Ca delivered the best PCE of 16.7%, whereas the one with high work function Au possessed the lowest PCE of 0.3%. These results were in a close agreement with experiments in literature. Photovoltaic parameters (FF, Jsc, and Voc) showed the same tendency and were responsible for the PCE. The band diagram revealed the formation of Schottky barrier was the main reason for the reduction in Voc, and the external quantum efficiency spectrum showed the adverse effect of the Schottky barrier on the charge extraction.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"436 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":"116145392","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 continued increase in both energy demand and greenhouse gas emissions (GHGs) call for utilising energy sources effectively. In comparison with traditional energy set-ups, micro-combined heat and power (micro-CHP) generation is viewed as an effective alternative; the aforementioned system’s definite electrical and thermal generation may be attributed to an augmented energy efficiency, decreased capacity as well as GHGs percentage. In this regard, organic Rankine cycle (ORC) has gained increasing recognition as a system, which is capable for generating electrical power from solar-based, waste heat, or thermal energy sources of a lower quality, for instance, below 120 °C. This study focuses on investigating a solar-based micro-CHP system’s performance for use in residential buildings through utilising a regenerative ORC. The analysis will focus on modelling and simulation as well as optimisation of operating condition of several working fluids (WFs) in ORC in order to use a heat source with low-temperature derived from solar thermal collectors for both heat and power generation. A parametric study has been carried out in detail for analysing the effects of different WFs at varying temperatures and flowrates from hot and cold sources on system performance. Significant changes were revealed in the study’s outcomes regarding performance including efficiency as well as power obtained from the expander and generator, taking into account the different temperatures of hot and cold sources for each WF. Work extraction carried out by the expander and electrical power had a range suitable for residential building applications; this range was 0.5–5 kWe with up to 60% electrical isentropic efficiency and up to 8% cycle efficiency for 50–120 °C temperature from a hot source. The operation of WFs will occur in the hot source temperature range, allowing the usage of either solar flat plate or evacuated tube collectors.
{"title":"Thermodynamic and Performance Study of Solar Regenerative Organic Rankine Cycle System for Use in Residential Micro-Combined Heat and Power Generation","authors":"W. Yaïci, E. Entchev","doi":"10.1115/es2019-3832","DOIUrl":"https://doi.org/10.1115/es2019-3832","url":null,"abstract":"\u0000 A continued increase in both energy demand and greenhouse gas emissions (GHGs) call for utilising energy sources effectively. In comparison with traditional energy set-ups, micro-combined heat and power (micro-CHP) generation is viewed as an effective alternative; the aforementioned system’s definite electrical and thermal generation may be attributed to an augmented energy efficiency, decreased capacity as well as GHGs percentage. In this regard, organic Rankine cycle (ORC) has gained increasing recognition as a system, which is capable for generating electrical power from solar-based, waste heat, or thermal energy sources of a lower quality, for instance, below 120 °C.\u0000 This study focuses on investigating a solar-based micro-CHP system’s performance for use in residential buildings through utilising a regenerative ORC. The analysis will focus on modelling and simulation as well as optimisation of operating condition of several working fluids (WFs) in ORC in order to use a heat source with low-temperature derived from solar thermal collectors for both heat and power generation.\u0000 A parametric study has been carried out in detail for analysing the effects of different WFs at varying temperatures and flowrates from hot and cold sources on system performance. Significant changes were revealed in the study’s outcomes regarding performance including efficiency as well as power obtained from the expander and generator, taking into account the different temperatures of hot and cold sources for each WF. Work extraction carried out by the expander and electrical power had a range suitable for residential building applications; this range was 0.5–5 kWe with up to 60% electrical isentropic efficiency and up to 8% cycle efficiency for 50–120 °C temperature from a hot source. The operation of WFs will occur in the hot source temperature range, allowing the usage of either solar flat plate or evacuated tube collectors.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"218 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":"128175462","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}
Iago G. Costa, J. Vargas, W. Balmant, A. Z. Filho, L. Ramos, D. M. Taher, A. Mariano
This work developed a process of extraction of crude oil from microalgae for production of hydrocarbon based fuel (green diesel). The microalgae Tetradesmus obliquus were cultivated in 12 m3 compact photobioreactors (FBRS) for 15 days using biodigester effluent as nutrients. Microalgae oil was obtained from the dry biomass through hot extraction with organic solvents (hexane and ethanol). After extraction the solvents were recovered from the sample using evaporation methods. After solvent recovery, the results showed that with pure ethanol, only 1.7% w/w crude oil was obtained, whereas with a mixture of hexane and ethanol the yield was 11.1% w/w. Fractional distillation was used as purification methods of the compounds in order to separate the nonsterifiable portion. The first process (pure hexane) after purification delivered 0.4% w/w, and the second process (hexane and ethanol) yielded 6.3% w/w. In addition, the sample was characterized using gas chromatography coupled to a mass spectrometer (GC-MS). An average of 70.6% w/w hydrocarbons ranging from C11 to C22 was found in the first experimental condition, and the main compounds were undecane (8.1% w/w) and pentadecane (10.62% w/w). For the second experimental condition, about 79.6% w/w hydrocarbons were found that varied from C13 to C23 and the main compounds were pentadecane (13.5% w/w) and heptadecane (11.28% w/w). The lower heating value of the purified microalgae oil was measured as 42,464.6 kJ·kg−1, whereas petroleum-based diesel has a lower heating value of 42,500.2 kJ·kg−1. In sum, green diesel from microalgae was proven to have potential to be a concrete alternative to replace diesel from the technical point of view.
{"title":"Green Diesel From Microalgae","authors":"Iago G. Costa, J. Vargas, W. Balmant, A. Z. Filho, L. Ramos, D. M. Taher, A. Mariano","doi":"10.1115/es2019-3959","DOIUrl":"https://doi.org/10.1115/es2019-3959","url":null,"abstract":"\u0000 This work developed a process of extraction of crude oil from microalgae for production of hydrocarbon based fuel (green diesel). The microalgae Tetradesmus obliquus were cultivated in 12 m3 compact photobioreactors (FBRS) for 15 days using biodigester effluent as nutrients. Microalgae oil was obtained from the dry biomass through hot extraction with organic solvents (hexane and ethanol). After extraction the solvents were recovered from the sample using evaporation methods. After solvent recovery, the results showed that with pure ethanol, only 1.7% w/w crude oil was obtained, whereas with a mixture of hexane and ethanol the yield was 11.1% w/w. Fractional distillation was used as purification methods of the compounds in order to separate the nonsterifiable portion. The first process (pure hexane) after purification delivered 0.4% w/w, and the second process (hexane and ethanol) yielded 6.3% w/w. In addition, the sample was characterized using gas chromatography coupled to a mass spectrometer (GC-MS). An average of 70.6% w/w hydrocarbons ranging from C11 to C22 was found in the first experimental condition, and the main compounds were undecane (8.1% w/w) and pentadecane (10.62% w/w). For the second experimental condition, about 79.6% w/w hydrocarbons were found that varied from C13 to C23 and the main compounds were pentadecane (13.5% w/w) and heptadecane (11.28% w/w). The lower heating value of the purified microalgae oil was measured as 42,464.6 kJ·kg−1, whereas petroleum-based diesel has a lower heating value of 42,500.2 kJ·kg−1. In sum, green diesel from microalgae was proven to have potential to be a concrete alternative to replace diesel from the technical point of view.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"50 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":"132311162","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 1 MWt falling particle receiver prototype was designed, built and is being evaluated at Sandia National Laboratories, National Solar Thermal Test Facility (NSTTF). The current prototype has a 1 m2 aperture facing the north field. The current aperture configuration is susceptible to heat and particle losses through the receiver aperture. Several options are being considered for the next design iteration to reduce the risk of heat and particle losses, in addition to improving the receiver efficiency to target levels of ∼90%. One option is to cover the receiver aperture with a highly durable and transmissive material such as quartz glass. Quartz glass has high transmittance for wavelengths less than 2.5 microns and low transmittance for wavelengths greater than 2.5 microns to help trap the heat inside the receiver. To evaluate the receiver optical performance, ray-tracing models were set up for several different aperture cover configurations. The falling particle receiver is modeled as a box with a 1 m2 aperture on the north side wall. The box dimensions are 1.57 m wide × 1.77 m tall × 1.67 m deep. The walls are composed of RSLE material modeled as Lambertian surfaces with reflectance of either 0.9 for the pristine condition or 0.5 for soiled walls. The quartz half-shell tubes are 1.46 m long with 105 mm and 110 mm inner and outer diameters, respectively. The half-shell tubes are arranged vertically and slant forward at the top by 30 degrees. Four configurations were considered: concave side of the half-shells facing away from the receiver aperture with (1) no spacing and (2) high spacing between the tubes, and concave side of the half-shells facing the aperture with (3) no spacing and (4) high spacing between the tubes. The particle curtain, in the first modeling approach, is modeled as a diffuse surface with transmittance, reflectance, and absorptance values, which are based on estimates from previous experiments for varying particle flow rates. The incident radiation is from the full NSTTF heliostat field with a single aimpoint at the center of the receiver aperture. The direct incident rays and reflected and scattered rays off the internal receiver surfaces are recorded on the internal walls and particle curtain surfaces as net incident irradiance. The net incident irradiances on the internal walls and particle curtain for the different aperture cover configuration are compared to the baseline configuration. In all cases, just from optical performance alone, the net incident irradiance is reduced from the baseline. However, it is expected that the quartz half-shells will reduce the convective and thermal radiation losses through the aperture. These ray-tracing results will be used as boundary conditions in computational fluid dynamics (CFD) analyses to determine the net receiver efficiency and optimal configuration for the quartz half-shells that minimize heat losses and maximize thermal efficiency.
{"title":"Optical Ray-Tracing Performance Modeling of Quartz Half-Shell Tubes Aperture Cover for Falling Particle Receiver","authors":"J. Yellowhair, C. Ho","doi":"10.1115/es2019-3927","DOIUrl":"https://doi.org/10.1115/es2019-3927","url":null,"abstract":"\u0000 A 1 MWt falling particle receiver prototype was designed, built and is being evaluated at Sandia National Laboratories, National Solar Thermal Test Facility (NSTTF). The current prototype has a 1 m2 aperture facing the north field. The current aperture configuration is susceptible to heat and particle losses through the receiver aperture. Several options are being considered for the next design iteration to reduce the risk of heat and particle losses, in addition to improving the receiver efficiency to target levels of ∼90%. One option is to cover the receiver aperture with a highly durable and transmissive material such as quartz glass. Quartz glass has high transmittance for wavelengths less than 2.5 microns and low transmittance for wavelengths greater than 2.5 microns to help trap the heat inside the receiver.\u0000 To evaluate the receiver optical performance, ray-tracing models were set up for several different aperture cover configurations. The falling particle receiver is modeled as a box with a 1 m2 aperture on the north side wall. The box dimensions are 1.57 m wide × 1.77 m tall × 1.67 m deep. The walls are composed of RSLE material modeled as Lambertian surfaces with reflectance of either 0.9 for the pristine condition or 0.5 for soiled walls. The quartz half-shell tubes are 1.46 m long with 105 mm and 110 mm inner and outer diameters, respectively. The half-shell tubes are arranged vertically and slant forward at the top by 30 degrees. Four configurations were considered: concave side of the half-shells facing away from the receiver aperture with (1) no spacing and (2) high spacing between the tubes, and concave side of the half-shells facing the aperture with (3) no spacing and (4) high spacing between the tubes. The particle curtain, in the first modeling approach, is modeled as a diffuse surface with transmittance, reflectance, and absorptance values, which are based on estimates from previous experiments for varying particle flow rates. The incident radiation is from the full NSTTF heliostat field with a single aimpoint at the center of the receiver aperture. The direct incident rays and reflected and scattered rays off the internal receiver surfaces are recorded on the internal walls and particle curtain surfaces as net incident irradiance. The net incident irradiances on the internal walls and particle curtain for the different aperture cover configuration are compared to the baseline configuration. In all cases, just from optical performance alone, the net incident irradiance is reduced from the baseline. However, it is expected that the quartz half-shells will reduce the convective and thermal radiation losses through the aperture. These ray-tracing results will be used as boundary conditions in computational fluid dynamics (CFD) analyses to determine the net receiver efficiency and optimal configuration for the quartz half-shells that minimize heat losses and maximize thermal efficiency.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"134 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":"133864869","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}
Gerard Lorenz D. Maandal, M. M. Tamayao, L. A. Danao
The technical feasibility of off-shore wind energy in the Philippines is assessed. Geographic information system is utilized to integrate the different technical data into a single model. Off-shore wind speed data for five years at elevations 10m, 20m, 80m, and 100m from a local database was used as reference for the wind resource study. Two wind turbines were considered for the energy conversion component, Siemens SWT-3.6-120 and Senvion 6.2 M126. The wind speed data was interpolated to 90m and 95m using standard power law to match the hub heights of the turbines studied. The wind power density, wind power, and annual energy production were calculated from the interpolated wind speeds. Areas in the Philippines with capacity factor greater than 30% and performance greater than 10% were considered technically viable. Exclusion criteria were applied to narrow down the potential siting for offshore wind farms, namely, active submerged cables, local ferry routes, marine protected areas, reefs, oil and gas extraction areas, bathymetry, distance to grid, typhoons, and earthquakes. Several sites were determined to be viable with north of Cagayan having the highest capacity factor. The highest wind capacity factor for the offshore wind farms are located in north of Ilocos Norte (SWT-3.6-120: 54.48%–62.60%; 6.2M126: 54.04%–64.79%), north of Occidental Mindoro (SWT-3.6-120: 46.81%–60.92%; 6.2M126: 45.30%–62.60%) and southeast of Oriental Mindoro (SWT-3.6-120: 45.60%–59.52%; 6.2M126: 45.30%–62.60%). However, these sites are not acceptable due to technical, social, and political constraints. The constraints considered in the study are active submerged cables with a buffer of 5 km, local ferry routes with a buffer of 3km, marine protected areas with a buffer 3 km, reefs with a buffer of 3 km, oil and gas extraction areas with a buffer of 5 km, bathymetry less than 50m, distance to grid of within 120 km, historical typhoon tracks with greater than 250 kph and 50 km buffer, and historical earthquakes with greater than 6.5 magnitude with a buffer of 15 km. Upon application of these exclusion criteria, the potential sites for offshore wind farms are north of Cagayan, west of Rizal, north of Camarines Sur, north of Samar, southwest of Masbate, Dinagat Island, Guimaras, and northeast of Palawan.
{"title":"An Analysis of the Technical Feasibility of Off-Shore Wind Energy in the Philippines","authors":"Gerard Lorenz D. Maandal, M. M. Tamayao, L. A. Danao","doi":"10.1115/es2019-3835","DOIUrl":"https://doi.org/10.1115/es2019-3835","url":null,"abstract":"\u0000 The technical feasibility of off-shore wind energy in the Philippines is assessed. Geographic information system is utilized to integrate the different technical data into a single model. Off-shore wind speed data for five years at elevations 10m, 20m, 80m, and 100m from a local database was used as reference for the wind resource study. Two wind turbines were considered for the energy conversion component, Siemens SWT-3.6-120 and Senvion 6.2 M126. The wind speed data was interpolated to 90m and 95m using standard power law to match the hub heights of the turbines studied. The wind power density, wind power, and annual energy production were calculated from the interpolated wind speeds. Areas in the Philippines with capacity factor greater than 30% and performance greater than 10% were considered technically viable. Exclusion criteria were applied to narrow down the potential siting for offshore wind farms, namely, active submerged cables, local ferry routes, marine protected areas, reefs, oil and gas extraction areas, bathymetry, distance to grid, typhoons, and earthquakes. Several sites were determined to be viable with north of Cagayan having the highest capacity factor. The highest wind capacity factor for the offshore wind farms are located in north of Ilocos Norte (SWT-3.6-120: 54.48%–62.60%; 6.2M126: 54.04%–64.79%), north of Occidental Mindoro (SWT-3.6-120: 46.81%–60.92%; 6.2M126: 45.30%–62.60%) and southeast of Oriental Mindoro (SWT-3.6-120: 45.60%–59.52%; 6.2M126: 45.30%–62.60%). However, these sites are not acceptable due to technical, social, and political constraints. The constraints considered in the study are active submerged cables with a buffer of 5 km, local ferry routes with a buffer of 3km, marine protected areas with a buffer 3 km, reefs with a buffer of 3 km, oil and gas extraction areas with a buffer of 5 km, bathymetry less than 50m, distance to grid of within 120 km, historical typhoon tracks with greater than 250 kph and 50 km buffer, and historical earthquakes with greater than 6.5 magnitude with a buffer of 15 km. Upon application of these exclusion criteria, the potential sites for offshore wind farms are north of Cagayan, west of Rizal, north of Camarines Sur, north of Samar, southwest of Masbate, Dinagat Island, Guimaras, and northeast of Palawan.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"78 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":"131382119","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}
H. Al-Ansary, A. El-Leathy, S. Jeter, M. Golob, C. Nguyen, Eldwin Djajadiwinata, Shaker Alaqel, Rageh S. Saeed, S. Abdel-Khalik, Z. Al-Suhaibani, S. Danish, Nader S. Saleh, A. Al-Balawi, F. Al-Harthi, Salem Bashraheel, Hatim Gandayh
Particle-based power tower systems are a promising technology that can allow operation of concentrating solar power (CSP) systems at temperatures higher than what today’s commercial molten salt systems can achieve, making them suitable for use in a variety of applications, including supercritical CO2 cycles, air Brayton cycles, and high-temperature process heat. In this concept, particles, instead of molten salt, are heated by the concentrated sunlight. In 2015, this concept was successfully tested at Sandia National Laboratories. In the mean time, an integrated system incorporating a particle heating receiver, a particle-to-air heat exchanger and a 100-kWe microturbine was designed, built, and tested at King Saud University in Riyadh, Saudi Arabia. The integrated system was run in 2018, and results from that test campaign were very promising, with temperatures of the particles leaving the receiver exceeding 600°C despite a number of challenges. The utility sponsoring the project is now planning to move forward with building a 1-MWe plant using the same concept, thereby moving closer to large-scale deployment, and making this facility the world’s first commercial concentrating solar power plant that uses the particle heating receiver concept. Moving from a 100-kWe scale to a 1-MWe scale requires modifications to the design of some components. The most likely plant location is the city of Duba in northwestern Saudi Arabia where the average daily total DNI is 7,170 Wh/m2 and an integrated solar combined cycle power plant exists on the premises. This paper discusses the design features of the main components of the new plant. Those features include a north field design, a 7.22-m2 single-sheet heliostat design, a cavity receiver to improve receiver efficiency by reducing radiative and convective losses, temperature-based particle flow regulation within the receiver, six hours of full-load thermal energy storage, with the tanks integrated into the tower structure and made of cost-effective masonry material, a shell-and-tube particle-to-air heat exchanger, a 45% efficiency recuperated intercooled gas turbine, and a high-temperature bucket elevator. The heliostat field was optimized using SolarPILOT. Results show that 1,302 heliostats are needed. The aperture area was found to be approximately 5.7 m2, while the total illuminated receiver surface area is about 16.8 m2. This design was found to be capable of achieving the particle temperature rise of 416°C, which is necessary to allow the turbine to rely entirely on the solar field to bring the temperature of air to the firing temperature of the turbine, thereby eliminating the need for fuel consumption except for back-up and for assistance at off-design conditions.
{"title":"Design Features of the World’s First Commercial Concentrating Solar Power Plant Using the Particle Heating Receiver Concept","authors":"H. Al-Ansary, A. El-Leathy, S. Jeter, M. Golob, C. Nguyen, Eldwin Djajadiwinata, Shaker Alaqel, Rageh S. Saeed, S. Abdel-Khalik, Z. Al-Suhaibani, S. Danish, Nader S. Saleh, A. Al-Balawi, F. Al-Harthi, Salem Bashraheel, Hatim Gandayh","doi":"10.1115/es2019-3856","DOIUrl":"https://doi.org/10.1115/es2019-3856","url":null,"abstract":"\u0000 Particle-based power tower systems are a promising technology that can allow operation of concentrating solar power (CSP) systems at temperatures higher than what today’s commercial molten salt systems can achieve, making them suitable for use in a variety of applications, including supercritical CO2 cycles, air Brayton cycles, and high-temperature process heat. In this concept, particles, instead of molten salt, are heated by the concentrated sunlight. In 2015, this concept was successfully tested at Sandia National Laboratories. In the mean time, an integrated system incorporating a particle heating receiver, a particle-to-air heat exchanger and a 100-kWe microturbine was designed, built, and tested at King Saud University in Riyadh, Saudi Arabia. The integrated system was run in 2018, and results from that test campaign were very promising, with temperatures of the particles leaving the receiver exceeding 600°C despite a number of challenges. The utility sponsoring the project is now planning to move forward with building a 1-MWe plant using the same concept, thereby moving closer to large-scale deployment, and making this facility the world’s first commercial concentrating solar power plant that uses the particle heating receiver concept. Moving from a 100-kWe scale to a 1-MWe scale requires modifications to the design of some components. The most likely plant location is the city of Duba in northwestern Saudi Arabia where the average daily total DNI is 7,170 Wh/m2 and an integrated solar combined cycle power plant exists on the premises. This paper discusses the design features of the main components of the new plant. Those features include a north field design, a 7.22-m2 single-sheet heliostat design, a cavity receiver to improve receiver efficiency by reducing radiative and convective losses, temperature-based particle flow regulation within the receiver, six hours of full-load thermal energy storage, with the tanks integrated into the tower structure and made of cost-effective masonry material, a shell-and-tube particle-to-air heat exchanger, a 45% efficiency recuperated intercooled gas turbine, and a high-temperature bucket elevator. The heliostat field was optimized using SolarPILOT. Results show that 1,302 heliostats are needed. The aperture area was found to be approximately 5.7 m2, while the total illuminated receiver surface area is about 16.8 m2. This design was found to be capable of achieving the particle temperature rise of 416°C, which is necessary to allow the turbine to rely entirely on the solar field to bring the temperature of air to the firing temperature of the turbine, thereby eliminating the need for fuel consumption except for back-up and for assistance at off-design conditions.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"81 12 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":"128138453","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}
Greenhouse gas emission reduction and the consequent decrease in the environmental impacts of fossil fuel can be achieved by cutting back on energy consumption in the building sector that consumes around 30% of total final energy around the globe. The building sector is a complex component of the modern economy and life and includes diverse types of structures, uses, and energy patterns. Such variability is a result of the way that buildings are designed, built, and used in addition to the variations of their materials, equipment, and users. From the start of the construction phase until their demolition, buildings involve energy consumption. A single building’s energy consumption pattern can be called its energy inertia, that is the way it consumes energy throughout its lifetime. Energy consumption also varies according to the age of the buildings. As a building gets older, its structure and equipment start losing their efficiency and often lead to increasing energy consumption over time. At any given time, the building sector is composed of structures of various ages. Some are under construction, others are recently built, some have lived to be mature and some quite old enough to be demolished. This complexity in the building sector creates a momentum against implementation of policies that reduce energy consumption. In this study, a system dynamic model is developed to perceive the temporal evolution of energy consumption and efficiency measures for the villa-type building stock in Qatar. This model tests energy efficiency policy measures such as renovation rates of 15 and 30 years, for buildings that are considered old, and also examines implementation of technology and building codes for new buildings. Results reveal savings of between 157 GWh and 1,275 GWh of electricity and reduction in CO2 emissions ranging from 77,000 tonnes to 602,000 tonnes.
{"title":"Building Stock Inertia and Impacts on Energy Consumption and CO2 Emissions in Qatar","authors":"Athar Kamal, Sami G. Al‐Ghamdi, M. Koç","doi":"10.1115/es2019-3854","DOIUrl":"https://doi.org/10.1115/es2019-3854","url":null,"abstract":"\u0000 Greenhouse gas emission reduction and the consequent decrease in the environmental impacts of fossil fuel can be achieved by cutting back on energy consumption in the building sector that consumes around 30% of total final energy around the globe. The building sector is a complex component of the modern economy and life and includes diverse types of structures, uses, and energy patterns. Such variability is a result of the way that buildings are designed, built, and used in addition to the variations of their materials, equipment, and users. From the start of the construction phase until their demolition, buildings involve energy consumption. A single building’s energy consumption pattern can be called its energy inertia, that is the way it consumes energy throughout its lifetime. Energy consumption also varies according to the age of the buildings. As a building gets older, its structure and equipment start losing their efficiency and often lead to increasing energy consumption over time. At any given time, the building sector is composed of structures of various ages. Some are under construction, others are recently built, some have lived to be mature and some quite old enough to be demolished. This complexity in the building sector creates a momentum against implementation of policies that reduce energy consumption. In this study, a system dynamic model is developed to perceive the temporal evolution of energy consumption and efficiency measures for the villa-type building stock in Qatar. This model tests energy efficiency policy measures such as renovation rates of 15 and 30 years, for buildings that are considered old, and also examines implementation of technology and building codes for new buildings. Results reveal savings of between 157 GWh and 1,275 GWh of electricity and reduction in CO2 emissions ranging from 77,000 tonnes to 602,000 tonnes.","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"120 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113940339","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. Golob, C. Nguyen, S. Jeter, S. Abdel-Khalik, C. Ho
Any proposed particle to working fluid heat exchanger as part of a CSP Particle Heating Receiver system is challenging. A principal challenge is achieving adequate heat exchange (HX) from the high temperature particles to the working fluid such as sCO2 or air flowing in tubes or other passages. To reduce the required HX area, a high particle side heat transfer coefficient is needed, and counterflow is always the best overall arrangement. Consequently, a promising approach is implementing an open channel flow of fluidized particles actually flowing in a general counterflow with respect to the working fluid, which is contained in tubes or passages immersed in the channel. This arrangement provides (1) excellent particle side heat transfer, (2) convenient particle re-circulation, and (3) almost ideal counterflow with the working fluid. To advance the understanding and support the design and applications of such exchangers, this investigation has been conducted to study the possibility of local effects of the particle flow path on the fluidized heat transfer. To this end, a series of smaller fluidized bed heat exchangers were built utilizing an axially flowing open channel for the moving bed of fluidized particles. These designs featured a serpentine flow path representative the full scale HX design proposed by others. The proposed serpentine flow design is based on an existing particle cooling system; however, questions were raised about this design that had not yet been conclusively answered and promoted this investigation. The test bath supporting this investigation contains one bend around which the particulate flows prior to exiting the heat exchanger. The intent of this larger scale apparatus is to observe the variables affecting the stability or uniformity of the particle flow and provide insight into potential problems with the operational unit. The test rig consists of two stacked sections. The lower container is the fluidizing air plenum, which provides a uniformly distributed airflow through the bottom plane of the upper container. The interface comprises a structural perforated plate, stacked layers of filter paper to balance the pressure drop, and a fine stainless steel wire mesh to ensure that the particulate remains in the upper container. This upper container represents the particulate flow area. Clear conductive PETG polymer walls were used for the fluidized bath to reduce electrostatic buildup while still providing a transparent material through which the flow can be observed. The current design uses an air conveyor to recirculate the particulate from one end of the test bath back to the other closing the particle loop. The tests described investigate the effectiveness of fluidization in specific regions of the serpentine path. Measurements have been taken in these regions to determine the local heat transfer coefficient. This is accomplished by inserting a cartridge heater with a known power input and heated area, instrumented
{"title":"Flowing Particle Fluidized Bath Design and Heat Transfer","authors":"M. Golob, C. Nguyen, S. Jeter, S. Abdel-Khalik, C. Ho","doi":"10.1115/es2019-3911","DOIUrl":"https://doi.org/10.1115/es2019-3911","url":null,"abstract":"\u0000 Any proposed particle to working fluid heat exchanger as part of a CSP Particle Heating Receiver system is challenging. A principal challenge is achieving adequate heat exchange (HX) from the high temperature particles to the working fluid such as sCO2 or air flowing in tubes or other passages. To reduce the required HX area, a high particle side heat transfer coefficient is needed, and counterflow is always the best overall arrangement. Consequently, a promising approach is implementing an open channel flow of fluidized particles actually flowing in a general counterflow with respect to the working fluid, which is contained in tubes or passages immersed in the channel. This arrangement provides (1) excellent particle side heat transfer, (2) convenient particle re-circulation, and (3) almost ideal counterflow with the working fluid. To advance the understanding and support the design and applications of such exchangers, this investigation has been conducted to study the possibility of local effects of the particle flow path on the fluidized heat transfer.\u0000 To this end, a series of smaller fluidized bed heat exchangers were built utilizing an axially flowing open channel for the moving bed of fluidized particles. These designs featured a serpentine flow path representative the full scale HX design proposed by others. The proposed serpentine flow design is based on an existing particle cooling system; however, questions were raised about this design that had not yet been conclusively answered and promoted this investigation. The test bath supporting this investigation contains one bend around which the particulate flows prior to exiting the heat exchanger. The intent of this larger scale apparatus is to observe the variables affecting the stability or uniformity of the particle flow and provide insight into potential problems with the operational unit.\u0000 The test rig consists of two stacked sections. The lower container is the fluidizing air plenum, which provides a uniformly distributed airflow through the bottom plane of the upper container. The interface comprises a structural perforated plate, stacked layers of filter paper to balance the pressure drop, and a fine stainless steel wire mesh to ensure that the particulate remains in the upper container. This upper container represents the particulate flow area. Clear conductive PETG polymer walls were used for the fluidized bath to reduce electrostatic buildup while still providing a transparent material through which the flow can be observed. The current design uses an air conveyor to recirculate the particulate from one end of the test bath back to the other closing the particle loop. The tests described investigate the effectiveness of fluidization in specific regions of the serpentine path. Measurements have been taken in these regions to determine the local heat transfer coefficient. This is accomplished by inserting a cartridge heater with a known power input and heated area, instrumented ","PeriodicalId":219138,"journal":{"name":"ASME 2019 13th International Conference on Energy Sustainability","volume":"43 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":"121709962","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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