E. Torres-Moreno, V. Moreno-Oliva, M. Campos-García, J. R. Dorrego-Portela, Orlando Lastres-Danguillecourt, N. Farrera-Vázquez
This study introduces a metrological approach to measure the aerodynamic shape and the twist of a wind turbine blade. The optical profilometer measurement technique used is laser triangulation. A camera records the image of a line projected onto a section of the blade and, by reconstructing the airfoil shape, the twist angular position of the profile with respect to the axial line of the blade is determined. This methodology is applied to test different sections of a Wortmann FX 63-137 airfoil with a length of 1700 mm. The results of the aerodynamic shape and twist angle are quantitatively verified by comparing them with the ideal or design values. The reconstruction process achieved a resolution of 0.06 mm, and measurement errors in the twist angular position were less than 0.1°. The presented method is efficient, accurate, and low cost to evaluate the blade profiles of low-power wind turbines. However, due to its easy implementation, it is expected to be able to measure any full-scale wind blade profile up to several meters in length.
本研究介绍了一种测量风力涡轮机叶片气动形状和扭曲度的计量方法。采用的光学轮廓仪测量技术是激光三角测量法。相机记录投射到叶片截面上的线条图像，通过重建翼面形状，确定轮廓相对于叶片轴线的扭曲角度位置。这种方法适用于测试长度为 1700 毫米的 Wortmann FX 63-137 机翼的不同部分。通过与理想值或设计值进行比较，对气动外形和扭转角的结果进行了定量验证。重建过程的分辨率达到了 0.06 毫米，扭转角位置的测量误差小于 0.1°。所提出的方法高效、准确、低成本，可用于评估小功率风力涡轮机的叶片轮廓。不过，由于该方法易于实施，预计可用于测量长度达数米的任何全尺寸风力叶片剖面。
{"title":"Use of an optical profilometer to measure the aerodynamic shape and the twist of a wind turbine blade","authors":"E. Torres-Moreno, V. Moreno-Oliva, M. Campos-García, J. R. Dorrego-Portela, Orlando Lastres-Danguillecourt, N. Farrera-Vázquez","doi":"10.1063/5.0176454","DOIUrl":"https://doi.org/10.1063/5.0176454","url":null,"abstract":"This study introduces a metrological approach to measure the aerodynamic shape and the twist of a wind turbine blade. The optical profilometer measurement technique used is laser triangulation. A camera records the image of a line projected onto a section of the blade and, by reconstructing the airfoil shape, the twist angular position of the profile with respect to the axial line of the blade is determined. This methodology is applied to test different sections of a Wortmann FX 63-137 airfoil with a length of 1700 mm. The results of the aerodynamic shape and twist angle are quantitatively verified by comparing them with the ideal or design values. The reconstruction process achieved a resolution of 0.06 mm, and measurement errors in the twist angular position were less than 0.1°. The presented method is efficient, accurate, and low cost to evaluate the blade profiles of low-power wind turbines. However, due to its easy implementation, it is expected to be able to measure any full-scale wind blade profile up to several meters in length.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"34 14","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139457599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Linsheng Dai, Zhumei Luo, Tao Guo, Haocheng Chao, Guanghe Dong, Zhikai Hu
With the increase in wind farms in hilly terrain, it is particularly important to explore the downstream wake expansion of wind turbines in hilly terrains. This study established two complex terrain-applicable super-Gaussian wake models based on the Coanda effect and the wind speed-up phenomenon. Then, by considering the wind shear effect and the law of mass conservation, two three-dimensional (3D) super-Gaussian wake models were obtained. The 3D super-Gaussian models were used to describe the shape of the wake deficit and could reflect the wake changes in the full wake region. The introduction of the Coanda effect could reflect the sinking of the wind turbine wake on the top of a hilly terrain. And considering that the wind speed-up phenomenon could better reflect the incoming velocity distribution of the actual hilly terrain. The validation results demonstrated that the prediction results of the 3D super-Gaussian wake models had negligible relative errors compared to the measured data and could better describe the vertical and horizontal expansion changes of the downstream wake. The models established in this study can assist with the development of complex terrain models and super-Gaussian models, as well as providing guidance for power prediction and wind turbine control strategies in complex terrain.
{"title":"Two three-dimensional super-Gaussian wake models for hilly terrain","authors":"Linsheng Dai, Zhumei Luo, Tao Guo, Haocheng Chao, Guanghe Dong, Zhikai Hu","doi":"10.1063/5.0174297","DOIUrl":"https://doi.org/10.1063/5.0174297","url":null,"abstract":"With the increase in wind farms in hilly terrain, it is particularly important to explore the downstream wake expansion of wind turbines in hilly terrains. This study established two complex terrain-applicable super-Gaussian wake models based on the Coanda effect and the wind speed-up phenomenon. Then, by considering the wind shear effect and the law of mass conservation, two three-dimensional (3D) super-Gaussian wake models were obtained. The 3D super-Gaussian models were used to describe the shape of the wake deficit and could reflect the wake changes in the full wake region. The introduction of the Coanda effect could reflect the sinking of the wind turbine wake on the top of a hilly terrain. And considering that the wind speed-up phenomenon could better reflect the incoming velocity distribution of the actual hilly terrain. The validation results demonstrated that the prediction results of the 3D super-Gaussian wake models had negligible relative errors compared to the measured data and could better describe the vertical and horizontal expansion changes of the downstream wake. The models established in this study can assist with the development of complex terrain models and super-Gaussian models, as well as providing guidance for power prediction and wind turbine control strategies in complex terrain.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"31 23","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139455595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wind farm design generally relies on the use of historical data and analytical wake models to predict farm quantities, such as annual energy production (AEP). Uncertainty in input wind data that drive these predictions can translate to significant uncertainty in output quantities. We examine two sources of uncertainty stemming from the level of description of the relevant meteorological variables and the source of the data. The former comes from a standard practice of simplifying the representation of the wind conditions in wake models, such as AEP estimates based on averaged turbulence intensity (TI), as opposed to instantaneous. Uncertainty from the data source arises from practical considerations related to the high cost of in situ measurements, especially for offshore wind farms. Instead, numerical weather prediction (NWP) modeling can be used to characterize the more exact location of the proposed site, with the trade-off of an imperfect model form. In the present work, both sources of input uncertainty are analyzed through a study of the site of the future Vineyard Wind 1 offshore wind farm. This site is analyzed using wind data from LiDAR measurements located 25 km from the farm and NWP data located within the farm. Error and uncertainty from the TI and data sources are quantified through forward analysis using an analytical wake model. We find that the impact of TI error on AEP predictions is negligible, while data source uncertainty results in 0.4%–3.7% uncertainty over feasible candidate hub heights for offshore wind farms, which can exceed interannual variability.
{"title":"Evaluation of wind resource uncertainty on energy production estimates for offshore wind farms","authors":"Kerry S. Klemmer, Emily P. Condon, M. Howland","doi":"10.1063/5.0166830","DOIUrl":"https://doi.org/10.1063/5.0166830","url":null,"abstract":"Wind farm design generally relies on the use of historical data and analytical wake models to predict farm quantities, such as annual energy production (AEP). Uncertainty in input wind data that drive these predictions can translate to significant uncertainty in output quantities. We examine two sources of uncertainty stemming from the level of description of the relevant meteorological variables and the source of the data. The former comes from a standard practice of simplifying the representation of the wind conditions in wake models, such as AEP estimates based on averaged turbulence intensity (TI), as opposed to instantaneous. Uncertainty from the data source arises from practical considerations related to the high cost of in situ measurements, especially for offshore wind farms. Instead, numerical weather prediction (NWP) modeling can be used to characterize the more exact location of the proposed site, with the trade-off of an imperfect model form. In the present work, both sources of input uncertainty are analyzed through a study of the site of the future Vineyard Wind 1 offshore wind farm. This site is analyzed using wind data from LiDAR measurements located 25 km from the farm and NWP data located within the farm. Error and uncertainty from the TI and data sources are quantified through forward analysis using an analytical wake model. We find that the impact of TI error on AEP predictions is negligible, while data source uncertainty results in 0.4%–3.7% uncertainty over feasible candidate hub heights for offshore wind farms, which can exceed interannual variability.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"33 28","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139455777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jitendra Kumar Yadav, B. Rani, Ajay Tiwari, Ambesh Dixit
The highly porous and binder-free flexible paper electrodes can enhance the specific capacitance of symmetric supercapacitors (SCs) due to their large surface and effective ion diffusion pathways. We synthesized the exfoliated graphite (ExG) by the thermal exfoliation method of chemically treated graphite flakes and compressed it into a paper-like thin sheet (binder-free) of ∼0.15 mm thickness. The coin cell SCs with copper (Cu) and stainless steel (SS) as current collectors have been fabricated for the electrochemical measurement. The cyclic voltammetry and galvanostatic charge/discharge measurements are investigated at various scan rates and current densities. The SCs with Cu foil as a current collector perform better than SS-based SCs. The Cu current collector-based SCs showed a specific capacitance of 37.08 mF cm−2, whereas it was ∼29.98 mF cm−2 for SS-based SCs at a 0.01 V s−1 scan rate across a 0–0.6 V potential window. Approximately no degradation in charge storage capacity for more than 15 000 cycles at 0.1 V s−1 shows the ultra-stability of the flexible ExG-based binder-free electrodes. A digital watch is powered using the fabricated pouch cell supercapacitor with copper-based current collectors to show the potential of SCs.
高多孔、无粘结剂的柔性纸电极因其大表面和有效的离子扩散途径，可提高对称超级电容器（SC）的比电容。我们采用热剥离法合成了经过化学处理的剥离石墨（ExG）薄片，并将其压制成厚度为 0.15 毫米的纸状薄片（无粘结剂）。以铜（Cu）和不锈钢（SS）为集流体的纽扣电池 SC 已制作完成，用于电化学测量。在不同的扫描速率和电流密度下进行了循环伏安法和电静态充放电测量。以铜箔为集流器的 SC 性能优于以 SS 为集流器的 SC。以 0.01 V s-1 的扫描速率扫描 0-0.6 V 电位窗口时，基于铜电流收集器的 SC 的比电容为 37.08 mF cm-2，而基于 SS 的 SC 的比电容为 29.98 mF cm-2。在 0.1 V s-1 的条件下，电荷存储容量在超过 15000 个循环后几乎没有下降，这表明基于 ExG 的柔性无粘结剂电极具有超强稳定性。为了展示超级电容器的潜力，我们利用制作的袋式电池超级电容器和铜基集流器为一块电子手表供电。
{"title":"High areal-capacitance based extremely stable flexible supercapacitors using binder-free exfoliated graphite paper electrode","authors":"Jitendra Kumar Yadav, B. Rani, Ajay Tiwari, Ambesh Dixit","doi":"10.1063/5.0184499","DOIUrl":"https://doi.org/10.1063/5.0184499","url":null,"abstract":"The highly porous and binder-free flexible paper electrodes can enhance the specific capacitance of symmetric supercapacitors (SCs) due to their large surface and effective ion diffusion pathways. We synthesized the exfoliated graphite (ExG) by the thermal exfoliation method of chemically treated graphite flakes and compressed it into a paper-like thin sheet (binder-free) of ∼0.15 mm thickness. The coin cell SCs with copper (Cu) and stainless steel (SS) as current collectors have been fabricated for the electrochemical measurement. The cyclic voltammetry and galvanostatic charge/discharge measurements are investigated at various scan rates and current densities. The SCs with Cu foil as a current collector perform better than SS-based SCs. The Cu current collector-based SCs showed a specific capacitance of 37.08 mF cm−2, whereas it was ∼29.98 mF cm−2 for SS-based SCs at a 0.01 V s−1 scan rate across a 0–0.6 V potential window. Approximately no degradation in charge storage capacity for more than 15 000 cycles at 0.1 V s−1 shows the ultra-stability of the flexible ExG-based binder-free electrodes. A digital watch is powered using the fabricated pouch cell supercapacitor with copper-based current collectors to show the potential of SCs.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"6 2","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139394788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Pichugina, R. Banta, E. J. Strobach, B. J. Carroll, W. A. Brewer, D. D. Turner, V. Wulfmeyer, E. James, T. R. Lee, S. Baidar, J. B. Olson, R. K. Newsom, H.-S. Bauer, R. Rai
The rapid change of wind speed and direction on 21 August 2017 is studied using Doppler lidar measurements at five sites of the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) facility in north-central Oklahoma. The Doppler lidar data were investigated along with meteorological variables such as temperature, humidity, and turbulence available from the large suite of instrumentation deployed at the SGP Central Facility (C1) during the Land-Atmosphere Feedback Experiment in August 2017. Lidar measurements at five sites, separated by 55–70 km, allowed us to document the development and evolution of the wind flow over the SGP area, examine synoptic conditions to understand the mechanism that leads to the ramp event, and estimate the ability of the High-Resolution Rapid Refresh model to reproduce this event. The flow feature in question is an atmospheric bore, a small-scale phenomenon that is challenging to represent in models, that was generated by a thunderstorm outflow northwest of the ARM SGP area. The small-scale nature of bores, its impact on power generation, and the modeling challenges associated with representing bores are discussed in this paper. The results also provide information about model errors between sites of different surface and vegetation types.
{"title":"Case study of a bore wind-ramp event from lidar measurements and HRRR simulations over ARM Southern Great Plains","authors":"Y. Pichugina, R. Banta, E. J. Strobach, B. J. Carroll, W. A. Brewer, D. D. Turner, V. Wulfmeyer, E. James, T. R. Lee, S. Baidar, J. B. Olson, R. K. Newsom, H.-S. Bauer, R. Rai","doi":"10.1063/5.0161905","DOIUrl":"https://doi.org/10.1063/5.0161905","url":null,"abstract":"The rapid change of wind speed and direction on 21 August 2017 is studied using Doppler lidar measurements at five sites of the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) facility in north-central Oklahoma. The Doppler lidar data were investigated along with meteorological variables such as temperature, humidity, and turbulence available from the large suite of instrumentation deployed at the SGP Central Facility (C1) during the Land-Atmosphere Feedback Experiment in August 2017. Lidar measurements at five sites, separated by 55–70 km, allowed us to document the development and evolution of the wind flow over the SGP area, examine synoptic conditions to understand the mechanism that leads to the ramp event, and estimate the ability of the High-Resolution Rapid Refresh model to reproduce this event. The flow feature in question is an atmospheric bore, a small-scale phenomenon that is challenging to represent in models, that was generated by a thunderstorm outflow northwest of the ARM SGP area. The small-scale nature of bores, its impact on power generation, and the modeling challenges associated with representing bores are discussed in this paper. The results also provide information about model errors between sites of different surface and vegetation types.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"75 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139395807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When the temperature of solar photovoltaic (PV) modules rises, efficiency drops and module degradation accelerates. Thus, it is beneficial to reduce module operating temperatures. Previous studies of solar power plants have illustrated that incoming flow characteristics, turbulent mixing, and array geometry can strongly impact convective cooling, as measured by the convective heat transfer coefficient h. In the fields of heat transfer and plant canopy flow, previous work has shown that system-scale arrangement modifications—e.g., variable spacing, barriers, or windbreaks—can passively alter the flow, enhance turbulent mixing, and influence convection. However, researchers have not yet explored how variable spacing or barriers might enhance convective cooling in solar power plants. Here, high-resolution large-eddy simulations model the air flow and heat transfer through solar power plant arrangements modified with missing modules and barrier walls. We then perform a control volume analysis to evaluate the net heat flux and compute h, which quantifies the influence of these spatial modifications on convective cooling and, thus, module temperature and power output. Installing barrier walls yields the greatest improvements, increasing h by 3.4%, reducing module temperature by an estimated 2.5 °C, and boosting power output by an estimated 1.4% on average. These findings indicate that incorporating variable spacing or barrier-type elements into PV plant designs can reduce module temperature and, thus, improve PV performance and service life.
{"title":"Barriers and variable spacing enhance convective cooling and increase power output in solar PV plants","authors":"B. Stanislawski, Todd Harman, R. B. Cal, M. Calaf","doi":"10.1063/5.0177420","DOIUrl":"https://doi.org/10.1063/5.0177420","url":null,"abstract":"When the temperature of solar photovoltaic (PV) modules rises, efficiency drops and module degradation accelerates. Thus, it is beneficial to reduce module operating temperatures. Previous studies of solar power plants have illustrated that incoming flow characteristics, turbulent mixing, and array geometry can strongly impact convective cooling, as measured by the convective heat transfer coefficient h. In the fields of heat transfer and plant canopy flow, previous work has shown that system-scale arrangement modifications—e.g., variable spacing, barriers, or windbreaks—can passively alter the flow, enhance turbulent mixing, and influence convection. However, researchers have not yet explored how variable spacing or barriers might enhance convective cooling in solar power plants. Here, high-resolution large-eddy simulations model the air flow and heat transfer through solar power plant arrangements modified with missing modules and barrier walls. We then perform a control volume analysis to evaluate the net heat flux and compute h, which quantifies the influence of these spatial modifications on convective cooling and, thus, module temperature and power output. Installing barrier walls yields the greatest improvements, increasing h by 3.4%, reducing module temperature by an estimated 2.5 °C, and boosting power output by an estimated 1.4% on average. These findings indicate that incorporating variable spacing or barrier-type elements into PV plant designs can reduce module temperature and, thus, improve PV performance and service life.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"118 26","pages":""},"PeriodicalIF":2.5,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139454017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Masoumeh Gharaati, Nathaniel J. Wei, J. Dabiri, L. Martínez‐Tossas, Di Yang
Effects of helical-shaped blades on the flow characteristics and power production of finite-length wind farms composed of vertical-axis wind turbines (VAWTs) are studied numerically using large-eddy simulation (LES). Two helical-bladed VAWTs (with opposite blade twist angles) are studied against one straight-bladed VAWT in different array configurations with coarse, intermediate, and tight spacings. Statistical analysis of the LES data shows that the helical-bladed VAWTs can improve the mean power production in the fully developed region of the array by about 4.94%–7.33% compared with the corresponding straight-bladed VAWT cases. The helical-bladed VAWTs also cover the azimuth angle more smoothly during the rotation, resulting in about 47.6%–60.1% reduction in the temporal fluctuation of the VAWT power output. Using the helical-bladed VAWTs also reduces the fatigue load on the structure by significantly reducing the spanwise bending moment (relative to the bottom base), which may improve the longevity of the VAWT system to reduce the long-term maintenance cost.
{"title":"Large-eddy simulations of turbulent flows in arrays of helical- and straight-bladed vertical-axis wind turbines","authors":"Masoumeh Gharaati, Nathaniel J. Wei, J. Dabiri, L. Martínez‐Tossas, Di Yang","doi":"10.1063/5.0172007","DOIUrl":"https://doi.org/10.1063/5.0172007","url":null,"abstract":"Effects of helical-shaped blades on the flow characteristics and power production of finite-length wind farms composed of vertical-axis wind turbines (VAWTs) are studied numerically using large-eddy simulation (LES). Two helical-bladed VAWTs (with opposite blade twist angles) are studied against one straight-bladed VAWT in different array configurations with coarse, intermediate, and tight spacings. Statistical analysis of the LES data shows that the helical-bladed VAWTs can improve the mean power production in the fully developed region of the array by about 4.94%–7.33% compared with the corresponding straight-bladed VAWT cases. The helical-bladed VAWTs also cover the azimuth angle more smoothly during the rotation, resulting in about 47.6%–60.1% reduction in the temporal fluctuation of the VAWT power output. Using the helical-bladed VAWTs also reduces the fatigue load on the structure by significantly reducing the spanwise bending moment (relative to the bottom base), which may improve the longevity of the VAWT system to reduce the long-term maintenance cost.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"52 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139291318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nico J. Dekker, L. Slooff, Mark J. Jansen, Gertjan de Graaff, Jaco Hovius, R. Jonkman, Jesper Zuurbier, Jan Pronk
The Dutch climate agreement anticipates the large-scale implementation of solar and wind energy systems on land and water. Combining solar and wind farms has the benefit of multiple surface area use, and it also has the advantage of energy generation from both solar and wind energy systems, which is rather complementary in time; thus, a better balance can be found between electricity generation and demand and the load on the electricity grid. In combined solar and wind farms (CSWFs), the turbines will cast shadows on the solar panels. This concerns the static shadow from the construction tower of the turbine as well as the dynamic shadow caused by the rotating blades. This paper reports on the results of millisecond data monitoring of the PV farm of a CSWF in the Netherlands on land. Static and dynamic shadow effects are discussed, as well as their dependency on farm design. It is observed that the dynamic shade of the wind turbine blade causes serious disturbances of the DC inputs of the inverter, resulting in deviation of the maximum power point tracking monitored. The shadow of the wind turbine results in a total energy loss of about 6% for the given period, park configuration, PV modules, inverter type, and setting.
{"title":"Wind turbine dynamic shading: The effects on combined solar and wind farms","authors":"Nico J. Dekker, L. Slooff, Mark J. Jansen, Gertjan de Graaff, Jaco Hovius, R. Jonkman, Jesper Zuurbier, Jan Pronk","doi":"10.1063/5.0176121","DOIUrl":"https://doi.org/10.1063/5.0176121","url":null,"abstract":"The Dutch climate agreement anticipates the large-scale implementation of solar and wind energy systems on land and water. Combining solar and wind farms has the benefit of multiple surface area use, and it also has the advantage of energy generation from both solar and wind energy systems, which is rather complementary in time; thus, a better balance can be found between electricity generation and demand and the load on the electricity grid. In combined solar and wind farms (CSWFs), the turbines will cast shadows on the solar panels. This concerns the static shadow from the construction tower of the turbine as well as the dynamic shadow caused by the rotating blades. This paper reports on the results of millisecond data monitoring of the PV farm of a CSWF in the Netherlands on land. Static and dynamic shadow effects are discussed, as well as their dependency on farm design. It is observed that the dynamic shade of the wind turbine blade causes serious disturbances of the DC inputs of the inverter, resulting in deviation of the maximum power point tracking monitored. The shadow of the wind turbine results in a total energy loss of about 6% for the given period, park configuration, PV modules, inverter type, and setting.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"15 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139303836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The abundance and replenishment nature of solid biomass prompt fuel substitution for gasification and thermal power plants. However, many challenges are encountered while utilizing raw biomass, such as seasonality, strong hydrophilicity, low bulk and energy density, excess oxygen content, less compositional homogeneity, and poor grindability. It is, therefore, indispensable to augment the thermo-chemical properties of the solid biomass by performing suitable pretreatment. Among the various pretreatment techniques, non-oxidative torrefaction effectively upgrades solid biomass to coal-like fuel altering its physico-chemical properties. Therefore, in this work, torrefaction of rice husk and sugarcane bagasse have been performed in a fixed bed reactor by varying temperatures from 210–330 °C and residence time from 30–60 min under a non-oxidative environment. The experimental investigation illustrates a decrease in mass and energy yield of the biomass with a rise in temperature and residence time. Conversely, the higher heating value of rice husk and sugarcane bagasse has improved by 119.4% and 128.9%, respectively. The hydrogen-to-carbon (H/C) and oxygen-to-carbon (O/C) ratio of the torrefied biomass has reduced to enriched fuel variety as indicated by the van Krevelen plot. The decomposition and structural modifications were assessed using Fourier transform infrared spectroscopy, x-ray diffraction, and morphology analysis. Based on the experimental observations, it has been found that torrefaction of rice husk at 290 °C and 30 min and sugarcane bagasse at 270 °C and 30 min would generate enriched syngas using a dual fluidized bed gasification system. Furthermore, water gas shift reactions will be promoted to enhance the percentage of hydrogen in the gas mixture.
固体生物质的丰富性和可再生性促使其成为气化和热电厂的替代燃料。然而，在利用原料生物质时会遇到许多挑战，如季节性、亲水性强、体积密度和能量密度低、含氧量过高、成分不均匀以及研磨性差等。因此，通过适当的预处理来增强固体生物质的热化学特性是必不可少的。在各种预处理技术中，非氧化预处理技术能有效地将固体生物质升级为煤燃料，并改变其物理化学特性。因此，本研究在非氧化环境下，通过改变 210-330 °C 的温度和 30-60 分钟的停留时间，在固定床反应器中对稻壳和甘蔗渣进行了热解。实验结果表明，随着温度和停留时间的增加，生物质的质量和能量产量都有所下降。相反，稻壳和甘蔗渣的较高热值分别提高了 119.4% 和 128.9%。从 van Krevelen 图中可以看出，焙烧生物质的氢碳比（H/C）和氧碳比（O/C）已经降低，成为富燃料品种。傅立叶变换红外光谱、X 射线衍射和形态分析评估了分解和结构改性情况。根据实验观察发现，在双流化床气化系统中，稻壳在 290 °C 和 30 分钟的温度下，甘蔗渣在 270 °C 和 30 分钟的温度下，都能产生富合成气。此外，还将促进水气变换反应，以提高气体混合物中氢的比例。
{"title":"Enrichment of fuel properties of biomass using non-oxidative torrefaction for gasification","authors":"Rabindra Kangsha Banik, Pankaj Kalita","doi":"10.1063/5.0168553","DOIUrl":"https://doi.org/10.1063/5.0168553","url":null,"abstract":"The abundance and replenishment nature of solid biomass prompt fuel substitution for gasification and thermal power plants. However, many challenges are encountered while utilizing raw biomass, such as seasonality, strong hydrophilicity, low bulk and energy density, excess oxygen content, less compositional homogeneity, and poor grindability. It is, therefore, indispensable to augment the thermo-chemical properties of the solid biomass by performing suitable pretreatment. Among the various pretreatment techniques, non-oxidative torrefaction effectively upgrades solid biomass to coal-like fuel altering its physico-chemical properties. Therefore, in this work, torrefaction of rice husk and sugarcane bagasse have been performed in a fixed bed reactor by varying temperatures from 210–330 °C and residence time from 30–60 min under a non-oxidative environment. The experimental investigation illustrates a decrease in mass and energy yield of the biomass with a rise in temperature and residence time. Conversely, the higher heating value of rice husk and sugarcane bagasse has improved by 119.4% and 128.9%, respectively. The hydrogen-to-carbon (H/C) and oxygen-to-carbon (O/C) ratio of the torrefied biomass has reduced to enriched fuel variety as indicated by the van Krevelen plot. The decomposition and structural modifications were assessed using Fourier transform infrared spectroscopy, x-ray diffraction, and morphology analysis. Based on the experimental observations, it has been found that torrefaction of rice husk at 290 °C and 30 min and sugarcane bagasse at 270 °C and 30 min would generate enriched syngas using a dual fluidized bed gasification system. Furthermore, water gas shift reactions will be promoted to enhance the percentage of hydrogen in the gas mixture.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"25 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139305147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Q. Cao, Y. Chen, K. Zhang, X. Zhang, Z. Cheng, B. Wen
Rotor redesign approaches have been widely proposed to solve the thrust mismatch issue caused by scaling effects for basin model tests of horizontal axis floating wind turbines (FWTs). However, limited basin model tests utilized the thrust-matched rotor (TMR) to accurately evaluate the aerodynamic loads applying to the vertical axis FWTs. This paper described the detailed design approach of the TMR of floating straight-bladed vertical axis wind turbines (VAWTs) with a rated power of 5.3 MW. First, the AG455 airfoil was selected to replace the NACA0018 airfoil. AG455 airfoil can show a larger lift coefficient and a smaller drag coefficient at low Reynolds number. On this basis, the load distribution match algorithm was used to assign the blade pitch angle and chord length at each section of the blade. This method takes the spanwise load and load change rate of model-scaled blade and full-scaled blade as the constraint conditions. By adopting this method, the rotor thrust can be tailored to match the prototype values across a wide range of tip speed ratios. This design approach proves advantageous in assessing the aerodynamic performance of VAWTs under varying inflow wind speeds and unsteady wind conditions. The redesigned TMR model under low Reynolds number can meet Froude similarity criterion, which is helpful to improve the accuracy of vertical axis FWT model tests in the wave basin.
{"title":"Design approach of thrust-matched rotor for basin model tests of floating straight-bladed vertical axis wind turbines","authors":"Q. Cao, Y. Chen, K. Zhang, X. Zhang, Z. Cheng, B. Wen","doi":"10.1063/5.0176064","DOIUrl":"https://doi.org/10.1063/5.0176064","url":null,"abstract":"Rotor redesign approaches have been widely proposed to solve the thrust mismatch issue caused by scaling effects for basin model tests of horizontal axis floating wind turbines (FWTs). However, limited basin model tests utilized the thrust-matched rotor (TMR) to accurately evaluate the aerodynamic loads applying to the vertical axis FWTs. This paper described the detailed design approach of the TMR of floating straight-bladed vertical axis wind turbines (VAWTs) with a rated power of 5.3 MW. First, the AG455 airfoil was selected to replace the NACA0018 airfoil. AG455 airfoil can show a larger lift coefficient and a smaller drag coefficient at low Reynolds number. On this basis, the load distribution match algorithm was used to assign the blade pitch angle and chord length at each section of the blade. This method takes the spanwise load and load change rate of model-scaled blade and full-scaled blade as the constraint conditions. By adopting this method, the rotor thrust can be tailored to match the prototype values across a wide range of tip speed ratios. This design approach proves advantageous in assessing the aerodynamic performance of VAWTs under varying inflow wind speeds and unsteady wind conditions. The redesigned TMR model under low Reynolds number can meet Froude similarity criterion, which is helpful to improve the accuracy of vertical axis FWT model tests in the wave basin.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"43 1","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139300103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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