The photovoltaic poverty alleviation project, part of the “Ten Major Precise Poverty Alleviation Projects” implemented by the Poverty Alleviation Office of the State Council, significantly contributes to eradicating poverty and rural revitalization. A difference-in-differences model was utilized in this study to assess this project's impact on rural households. This analysis used tracking data from households both with photovoltaic equipment installed and without in “S Town,” Jiangsu Province, from 2017 to 2021. The results indicate that photovoltaic installations lead to an increase in per capita disposable income, hence reducing poverty. However, further analysis suggests that better health and work capacity in disadvantaged households correlate with lesser benefits from the photovoltaic project in terms of income. The policy implications of these findings include a necessity for developing innovative models in the photovoltaic sector to enhance conditions for farmers, reducing their dependence on government subsidies.
{"title":"Impact of photovoltaic power generation on poverty alleviation in Jiangsu, China","authors":"Wenbo Li, Jiaxin Huang, LingJing Kong, Dongzhen Liang","doi":"10.1063/5.0208522","DOIUrl":"https://doi.org/10.1063/5.0208522","url":null,"abstract":"The photovoltaic poverty alleviation project, part of the “Ten Major Precise Poverty Alleviation Projects” implemented by the Poverty Alleviation Office of the State Council, significantly contributes to eradicating poverty and rural revitalization. A difference-in-differences model was utilized in this study to assess this project's impact on rural households. This analysis used tracking data from households both with photovoltaic equipment installed and without in “S Town,” Jiangsu Province, from 2017 to 2021. The results indicate that photovoltaic installations lead to an increase in per capita disposable income, hence reducing poverty. However, further analysis suggests that better health and work capacity in disadvantaged households correlate with lesser benefits from the photovoltaic project in terms of income. The policy implications of these findings include a necessity for developing innovative models in the photovoltaic sector to enhance conditions for farmers, reducing their dependence on government subsidies.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141698242","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}
Wenlong Zhang, Yufei Zhang, Xiangdong Li, Ruixiong Li, Huanran Wang, Peng Jin, Junyu Du, Yaoguang Song
To improve the performance of the compressed air energy storage (CAES) system, flow and heat transfer in different air storage tank (AST) configurations are investigated using numerical simulations after the numerical model has been experimentally validated. System performance for different AST placement methods is analyzed through numerical simulations integrated with the thermodynamic model of advanced adiabatic compressed air energy storage (AA-CAES). An in-depth study examines the impact of key system parameters on system performance with different AST configurations. Based on these analyses, the AA-CAES system with a constant volume of AST is optimized. The results indicate that horizontal placement of the AST improves heat transfer capability within the same working pressure range but results in slightly lower energy storage efficiency, achieving 64.61% compared to 65.50% for vertical placement. However, horizontal placement offers higher energy storage density, achieving 3.54 kW h/m3 under specific conditions, compared to 3.14 kW h/m3 for vertical placement. As the energy storage flow rate increases, exceeding the critical flow rate significantly improves heat transfer in vertically placed ASTs, thus narrowing the energy storage density gap between configurations. Increased turbine efficiency, additional external heat sources, and further utilization of compression heat provide more significant performance improvements for the AA-CAES with the AST placed horizontally compared to vertically. Compared to the AA-CAES with vertically placed ASTs, the configuration of the ASTs is optimized to enhance the electrical output of the AA-CAES by 76.4 MW h and reduce the input by 78.9 MW h at a storage flow rate of 0.5 kg/s.
{"title":"Performance analysis and configuration method optimization of AA-CAES-based air storage tanks","authors":"Wenlong Zhang, Yufei Zhang, Xiangdong Li, Ruixiong Li, Huanran Wang, Peng Jin, Junyu Du, Yaoguang Song","doi":"10.1063/5.0206283","DOIUrl":"https://doi.org/10.1063/5.0206283","url":null,"abstract":"To improve the performance of the compressed air energy storage (CAES) system, flow and heat transfer in different air storage tank (AST) configurations are investigated using numerical simulations after the numerical model has been experimentally validated. System performance for different AST placement methods is analyzed through numerical simulations integrated with the thermodynamic model of advanced adiabatic compressed air energy storage (AA-CAES). An in-depth study examines the impact of key system parameters on system performance with different AST configurations. Based on these analyses, the AA-CAES system with a constant volume of AST is optimized. The results indicate that horizontal placement of the AST improves heat transfer capability within the same working pressure range but results in slightly lower energy storage efficiency, achieving 64.61% compared to 65.50% for vertical placement. However, horizontal placement offers higher energy storage density, achieving 3.54 kW h/m3 under specific conditions, compared to 3.14 kW h/m3 for vertical placement. As the energy storage flow rate increases, exceeding the critical flow rate significantly improves heat transfer in vertically placed ASTs, thus narrowing the energy storage density gap between configurations. Increased turbine efficiency, additional external heat sources, and further utilization of compression heat provide more significant performance improvements for the AA-CAES with the AST placed horizontally compared to vertically. Compared to the AA-CAES with vertically placed ASTs, the configuration of the ASTs is optimized to enhance the electrical output of the AA-CAES by 76.4 MW h and reduce the input by 78.9 MW h at a storage flow rate of 0.5 kg/s.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141716758","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}
A current global trend is the production of green hydrogen via electrolysis of fresh water, preferably extracted from regions that have an abundance of renewable energy, to contribute to the mitigation of global warming. Despite being considered a source of fresh water, Brazil is experiencing a water crisis, with a shortage of water to meet agriculture and hydroelectric generation due to climate effects that affect the water cycle. With the forecast of increasing population and increasing demand for fresh water for consumption, agriculture, and industry, it is necessary to investigate opportunities for the generation of green hydrogen. This article presents results of technical and economic feasibility analyses of eight green hydrogen production systems for export, derived from two main concepts of seawater desalination plants aimed at preserving freshwater for other more noble purposes. All the analyzed systems use electrical and (or) thermal energy generation plants derived from solar and wind energy, with emphasis on heliothermal energy concentration systems. It is observed that the heliothermal systems, generators of electric and thermal energy, require higher investment costs; however, they have hydrogen production costs compatible with those of the other systems and dispatchable daily production of hydrogen and desalinated water. Furthermore, a system that combines thermal energy from a heliothermal plant to drive a thermal desalination plant and electrical energy from photovoltaic and wind plants to drive the electrolyzers was very well classified. Finally, it is verified that desalination plants have negligible investment cost compared to the cost of power and hydrogen plants.
{"title":"Production of green hydrogen in Brazil for exportation from desalinated seawater using energy generated by heliothermal, photovoltaic, and wind plants","authors":"José Henrique Martins Neto","doi":"10.1063/5.0206514","DOIUrl":"https://doi.org/10.1063/5.0206514","url":null,"abstract":"A current global trend is the production of green hydrogen via electrolysis of fresh water, preferably extracted from regions that have an abundance of renewable energy, to contribute to the mitigation of global warming. Despite being considered a source of fresh water, Brazil is experiencing a water crisis, with a shortage of water to meet agriculture and hydroelectric generation due to climate effects that affect the water cycle. With the forecast of increasing population and increasing demand for fresh water for consumption, agriculture, and industry, it is necessary to investigate opportunities for the generation of green hydrogen. This article presents results of technical and economic feasibility analyses of eight green hydrogen production systems for export, derived from two main concepts of seawater desalination plants aimed at preserving freshwater for other more noble purposes. All the analyzed systems use electrical and (or) thermal energy generation plants derived from solar and wind energy, with emphasis on heliothermal energy concentration systems. It is observed that the heliothermal systems, generators of electric and thermal energy, require higher investment costs; however, they have hydrogen production costs compatible with those of the other systems and dispatchable daily production of hydrogen and desalinated water. Furthermore, a system that combines thermal energy from a heliothermal plant to drive a thermal desalination plant and electrical energy from photovoltaic and wind plants to drive the electrolyzers was very well classified. Finally, it is verified that desalination plants have negligible investment cost compared to the cost of power and hydrogen plants.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141849152","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}
Rural China grapples with pervasive energy poverty. This study aims to measure China's rural energy poverty and propose early warning strategies. It establishes a rural energy relative poverty evaluation system based on four dimensions: energy service effectiveness, consumption cleanliness, management integrity, and development sustainability. Using the Analytic Hierarchy Process-Criteria Importance Though Intercriteria Correlation-Technique for Order Preference by Similarity to Ideal Solution model, it calculates rural energy poverty indices for Chinese provinces, while ward cluster analysis sets regional and hierarchical early warning criteria. Findings indicate: (1) China's rural energy poverty index varies widely, with a low range of 0.49–0.52 and a high range above 0.65. The top 14 regions average a rural energy poverty index of 0.62. (2) Over 2015–2021, there is a 9.70% decrease in the index, indicating a general downward trend. While rural energy services' efficiency and management integrity improve, consumption cleanliness and development sustainability decline. (3) Spatially, energy poverty is higher in the west and north, notably lower in the east and south. The eastern coastal and central regions exhibit significantly lower poverty levels due to better economic foundations and leading energy transformations. (4) Nine provinces are red warning areas, witnessing declining sustainability but improving service effectiveness, consumption cleanliness, and management integrity. Weak links in energy poverty vary across regions in terms of service effectiveness, consumption cleanliness, management integrity, and development sustainability. This study enhances the rural energy poverty evaluation system and proposes regional, hierarchical, and phased early warning standards.
{"title":"Assessing rural energy poverty and early warning based on long-run evolution for clean energy transition in China","authors":"S. Yin, Man Wang, Yaqi Shi, Yumeng Zhao","doi":"10.1063/5.0209376","DOIUrl":"https://doi.org/10.1063/5.0209376","url":null,"abstract":"Rural China grapples with pervasive energy poverty. This study aims to measure China's rural energy poverty and propose early warning strategies. It establishes a rural energy relative poverty evaluation system based on four dimensions: energy service effectiveness, consumption cleanliness, management integrity, and development sustainability. Using the Analytic Hierarchy Process-Criteria Importance Though Intercriteria Correlation-Technique for Order Preference by Similarity to Ideal Solution model, it calculates rural energy poverty indices for Chinese provinces, while ward cluster analysis sets regional and hierarchical early warning criteria. Findings indicate: (1) China's rural energy poverty index varies widely, with a low range of 0.49–0.52 and a high range above 0.65. The top 14 regions average a rural energy poverty index of 0.62. (2) Over 2015–2021, there is a 9.70% decrease in the index, indicating a general downward trend. While rural energy services' efficiency and management integrity improve, consumption cleanliness and development sustainability decline. (3) Spatially, energy poverty is higher in the west and north, notably lower in the east and south. The eastern coastal and central regions exhibit significantly lower poverty levels due to better economic foundations and leading energy transformations. (4) Nine provinces are red warning areas, witnessing declining sustainability but improving service effectiveness, consumption cleanliness, and management integrity. Weak links in energy poverty vary across regions in terms of service effectiveness, consumption cleanliness, management integrity, and development sustainability. This study enhances the rural energy poverty evaluation system and proposes regional, hierarchical, and phased early warning standards.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141696211","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}
Constructing accurate spatiotemporal correlations is a challenging task in joint prediction of multiple photovoltaic sites. Some advanced algorithms for incorporating other surrounding site information have been proposed, such as graph neural network-based methods, which are usually based on static or dynamic graphs to build spatial dependencies between sites. However, the possibility of the simultaneous existence of multiple spatial dependencies is not considered. This paper establishes a spatiotemporal prediction model based on hybrid spatiotemporal graph neural network. In this model, we apply adaptive hybrid graph learning to learn composite spatial correlations among multiple sites. A temporal convolution module with multi-subsequence temporal data input is used to extract local semantic information to better predict future nonlinear temporal dependencies. A spatiotemporal adaptive fusion module is added to address the issue of integrating diverse spatiotemporal trends among multiple sites. To assess the model's predictive performance, nine solar radiation observation stations were selected in two different climatic environments. The average root mean square error (RMSE) of the constructed model was 38.51 and 49.90 W/m2, with average mean absolute error (MAE) of 14.72 and 23.06 W/m2, respectively. Single-site and multi-site prediction models were selected as baseline models. Compared with the baseline models, the RMSE and MAE reduce by 3.1%–20.8% and 8.9%–32.8%, respectively, across all sites. The proposed model demonstrates the effectiveness of improving accuracy in forecasting solar irradiance through multi-site predictions.
{"title":"Multi-site solar irradiance prediction based on hybrid spatiotemporal graph neural network","authors":"Yunjun Yu, Zejie Cheng, Biao Xiong, Qian Li","doi":"10.1063/5.0207462","DOIUrl":"https://doi.org/10.1063/5.0207462","url":null,"abstract":"Constructing accurate spatiotemporal correlations is a challenging task in joint prediction of multiple photovoltaic sites. Some advanced algorithms for incorporating other surrounding site information have been proposed, such as graph neural network-based methods, which are usually based on static or dynamic graphs to build spatial dependencies between sites. However, the possibility of the simultaneous existence of multiple spatial dependencies is not considered. This paper establishes a spatiotemporal prediction model based on hybrid spatiotemporal graph neural network. In this model, we apply adaptive hybrid graph learning to learn composite spatial correlations among multiple sites. A temporal convolution module with multi-subsequence temporal data input is used to extract local semantic information to better predict future nonlinear temporal dependencies. A spatiotemporal adaptive fusion module is added to address the issue of integrating diverse spatiotemporal trends among multiple sites. To assess the model's predictive performance, nine solar radiation observation stations were selected in two different climatic environments. The average root mean square error (RMSE) of the constructed model was 38.51 and 49.90 W/m2, with average mean absolute error (MAE) of 14.72 and 23.06 W/m2, respectively. Single-site and multi-site prediction models were selected as baseline models. Compared with the baseline models, the RMSE and MAE reduce by 3.1%–20.8% and 8.9%–32.8%, respectively, across all sites. The proposed model demonstrates the effectiveness of improving accuracy in forecasting solar irradiance through multi-site predictions.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141699549","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}
In the multirotor system of a wind turbine, the overall power generation is greatly influenced by the placement and interaction of rotors in proximity. Thus, a great deal of study is needed to ascertain the integration strategy of small wind turbines. In this paper, the wake flow patterns have been investigated for two model wind turbines, viz., single-rotor and double-rotor arrangements operating at a low tip speed ratio. The model rotors composed of SG6043 airfoil have a similar configuration. In the single-rotor arrangement, the model rotor is placed at the center of the wind tunnel. While in the double-rotor arrangement, the model rotors are placed at an equal distance from the central line axis of the wind tunnel. To understand the wake propagation and interaction, experiments have been performed at various wind speed conditions such that the corresponding tip speed ratio is kept between 2.5 and 3. The study is, therefore, specifically focused on the wake characteristics of the rotors under low λ, and the assessment has been made within the near wake region. The span-wise and stream-wise assessments of the wake for the double rotor suggest a minimal velocity deficit close to the rotor plane and a higher deficit downstream contrary to the single-rotor configuration.
{"title":"Wake flow characteristics of small wind turbine models with single- and double-rotor arrangements: A wind tunnel study","authors":"Ravi Kumar, Ojing Siram, U. Saha, Niranjan Sahoo","doi":"10.1063/5.0215625","DOIUrl":"https://doi.org/10.1063/5.0215625","url":null,"abstract":"In the multirotor system of a wind turbine, the overall power generation is greatly influenced by the placement and interaction of rotors in proximity. Thus, a great deal of study is needed to ascertain the integration strategy of small wind turbines. In this paper, the wake flow patterns have been investigated for two model wind turbines, viz., single-rotor and double-rotor arrangements operating at a low tip speed ratio. The model rotors composed of SG6043 airfoil have a similar configuration. In the single-rotor arrangement, the model rotor is placed at the center of the wind tunnel. While in the double-rotor arrangement, the model rotors are placed at an equal distance from the central line axis of the wind tunnel. To understand the wake propagation and interaction, experiments have been performed at various wind speed conditions such that the corresponding tip speed ratio is kept between 2.5 and 3. The study is, therefore, specifically focused on the wake characteristics of the rotors under low λ, and the assessment has been made within the near wake region. The span-wise and stream-wise assessments of the wake for the double rotor suggest a minimal velocity deficit close to the rotor plane and a higher deficit downstream contrary to the single-rotor configuration.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141847707","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}
Power-to-gas technology and demand response strategy are effective approaches to improve the flexibility and efficiency of energy systems. This paper proposes a multi-objective operation optimization model for an electro-thermal integrated energy system considering power to gas and demand response strategies. First, the structure of integrated energy system and the demand response model of different types of electro-thermal loads are proposed. Second, the operation optimization model of integrated energy system is established with three objectives of total cost minimization, carbon emission minimization, and energy curtailment rate minimization. A hybrid intelligent algorithm combining multi-objective particle swarm optimization and VlseKriterijumska Optimizacija I Kompromisno Resenje technique is employed to solve the proposed model. Then, an industrial park in North China is studied. The results indicate that power to gas can reduce the total cost, carbon emission, and energy curtailment rate by 8.18%, 11.92%, and 75.80%, respectively, and the demand response also has a positive impact on system performance.
电转气技术和需求响应策略是提高能源系统灵活性和效率的有效方法。本文提出了一种考虑电转气和需求响应策略的电热综合能源系统多目标运行优化模型。首先，提出了综合能源系统的结构和不同类型电热负荷的需求响应模型。其次，以总成本最小化、碳排放最小化和能源削减率最小化三个目标为基础，建立了综合能源系统的运行优化模型。采用多目标粒子群优化和 VlseKriterijumska Optimizacija I Kompromisno Resenje 技术相结合的混合智能算法来求解所提出的模型。然后，对华北某工业园区进行了研究。结果表明，电改气可使总成本、碳排放和能源削减率分别降低 8.18%、11.92% 和 75.80%，需求响应也对系统性能产生了积极影响。
{"title":"A multi-objective operation optimization model for the electro-thermal integrated energy systems considering power to gas and multi-type demand response","authors":"Fangqiu Xu, Xiaopeng Li, Chunhua Jin","doi":"10.1063/5.0217570","DOIUrl":"https://doi.org/10.1063/5.0217570","url":null,"abstract":"Power-to-gas technology and demand response strategy are effective approaches to improve the flexibility and efficiency of energy systems. This paper proposes a multi-objective operation optimization model for an electro-thermal integrated energy system considering power to gas and demand response strategies. First, the structure of integrated energy system and the demand response model of different types of electro-thermal loads are proposed. Second, the operation optimization model of integrated energy system is established with three objectives of total cost minimization, carbon emission minimization, and energy curtailment rate minimization. A hybrid intelligent algorithm combining multi-objective particle swarm optimization and VlseKriterijumska Optimizacija I Kompromisno Resenje technique is employed to solve the proposed model. Then, an industrial park in North China is studied. The results indicate that power to gas can reduce the total cost, carbon emission, and energy curtailment rate by 8.18%, 11.92%, and 75.80%, respectively, and the demand response also has a positive impact on system performance.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141707320","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}
Synthetic jets (SJs) offer a promising technique for enhancing aerodynamic efficiency in vertical-axis wind turbines (VAWTs) by controlling boundary layer separation on airfoils. This study uses computational fluid dynamics simulations to investigate the impact of SJs on a VAWT. The results show that SJs effectively delay stall onset, increasing lift coefficient at high angles of attack, leading to an estimated 17% improvement in output power when applied to full VAWT simulations using the actuator line model at Tip Speed Ratio equal to 3. Additionally, the study suggests SJs may positively affect wake behavior by reducing turbulence and modifying wake velocity profiles, which could further influence power generation in wind farms. This research underscores the importance of model selection in accurately predicting the aerodynamic benefits of SJs, providing a foundational understanding for future exploration in VAWT applications.
{"title":"A computational fluid dynamics analysis on enhancing wind turbine efficiency through synthetic jet actuation","authors":"A. Matiz-Chicacausa, S. Molano, O. L. Mejia","doi":"10.1063/5.0208120","DOIUrl":"https://doi.org/10.1063/5.0208120","url":null,"abstract":"Synthetic jets (SJs) offer a promising technique for enhancing aerodynamic efficiency in vertical-axis wind turbines (VAWTs) by controlling boundary layer separation on airfoils. This study uses computational fluid dynamics simulations to investigate the impact of SJs on a VAWT. The results show that SJs effectively delay stall onset, increasing lift coefficient at high angles of attack, leading to an estimated 17% improvement in output power when applied to full VAWT simulations using the actuator line model at Tip Speed Ratio equal to 3. Additionally, the study suggests SJs may positively affect wake behavior by reducing turbulence and modifying wake velocity profiles, which could further influence power generation in wind farms. This research underscores the importance of model selection in accurately predicting the aerodynamic benefits of SJs, providing a foundational understanding for future exploration in VAWT applications.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141714214","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}
Ye Qiu, Haijun Wei, Daping Zhou, Xinyi Zhou, Tie Li
To assist vessels in meeting the net-zero emission target set by the International Maritime Organization for 2050, this article investigates the emission and combustion characteristics of biodiesel–ammonia dual-fuel engines. This research investigates the impact of various ammonia mass ratios (AMRs, m%) at 0, 14.67%, 29.48%, 46.21%, 58.73%, and 82.72% on the combustion and emission performance of biodiesel–ammonia dual-fuel engines at fixed speed and load. The results show that the biodiesel–ammonia dual-fuel engine is capable of operating at a substantial AMR of 82.72%. In addition, as the AMR increased, the in-cylinder pressure and brake thermal efficiency decreased. The heat release rate peaked at 57.13% AMR. When compared to the only-biodiesel mode, NOx, CO2, and soot emissions are significantly reduced. CO2 and soot emissions decreased by 63.43% and 60%, respectively, at 82.72% AMR, while NOx emissions fell by 34.15% at 58.73% AMR. The emissions of N2O and unburned ammonia rose linearly as AMR increased. The increase in N2O did not counteract the substantial fall in CO2e. CO2e fell by 63.12% at 82.72% AMR, following a trend to similar CO2.
为帮助船舶实现国际海事组织设定的 2050 年净零排放目标，本文研究了生物柴油-氨气双燃料发动机的排放和燃烧特性。该研究调查了不同氨气质量比（AMRs，m%）（0、14.67%、29.48%、46.21%、58.73% 和 82.72%）对生物柴油-氨气双燃料发动机在固定转速和负荷下的燃烧和排放性能的影响。结果表明，生物柴油-氨气双燃料发动机能够在 82.72% 的大幅 AMR 下运行。此外，随着 AMR 的增加，缸内压力和制动热效率都有所下降。热释放率在 AMR 为 57.13% 时达到峰值。与仅使用生物柴油的模式相比，氮氧化物、二氧化碳和烟尘排放量显著减少。在 82.72% AMR 时，二氧化碳和烟尘排放量分别减少了 63.43% 和 60%，而在 58.73% AMR 时，氮氧化物排放量减少了 34.15%。随着 AMR 的增加，N2O 和未燃烧氨的排放量呈线性上升。N2O 的增加并没有抵消 CO2e 的大幅下降。在 AMR 为 82.72% 时，CO2e 下降了 63.12%，其趋势与 CO2 相似。
{"title":"Experimental study on the effect of combustion and emission performance of biodiesel–ammonia dual-fuel engine","authors":"Ye Qiu, Haijun Wei, Daping Zhou, Xinyi Zhou, Tie Li","doi":"10.1063/5.0208372","DOIUrl":"https://doi.org/10.1063/5.0208372","url":null,"abstract":"To assist vessels in meeting the net-zero emission target set by the International Maritime Organization for 2050, this article investigates the emission and combustion characteristics of biodiesel–ammonia dual-fuel engines. This research investigates the impact of various ammonia mass ratios (AMRs, m%) at 0, 14.67%, 29.48%, 46.21%, 58.73%, and 82.72% on the combustion and emission performance of biodiesel–ammonia dual-fuel engines at fixed speed and load. The results show that the biodiesel–ammonia dual-fuel engine is capable of operating at a substantial AMR of 82.72%. In addition, as the AMR increased, the in-cylinder pressure and brake thermal efficiency decreased. The heat release rate peaked at 57.13% AMR. When compared to the only-biodiesel mode, NOx, CO2, and soot emissions are significantly reduced. CO2 and soot emissions decreased by 63.43% and 60%, respectively, at 82.72% AMR, while NOx emissions fell by 34.15% at 58.73% AMR. The emissions of N2O and unburned ammonia rose linearly as AMR increased. The increase in N2O did not counteract the substantial fall in CO2e. CO2e fell by 63.12% at 82.72% AMR, following a trend to similar CO2.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141843280","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}
R. Newsom, R. Krishnamurthy, Duli Chand, M. Pekour, Colleen M Kaul, Donna Flynn, L. Goldberger, R. Rai, S. Wharton
Dual-Doppler lidar measurements were made during the American WAKE ExperimeNt to provide height-resolved measurements of wind speed and direction at multiple locations immediately south of the leading row turbines in the King Plains wind farm in Oklahoma. These so-called virtual tower measurements were performed to characterize the inflow into the wind farm and to assess possible upwind blockage effects due to the collective action of the wind farm. The campaign was conducted from 12 November 2022 to 17 October 2023, during which time 14 unique virtual tower locations were sampled with heights ranging from 240 to 490 m AGL. The wind retrieval algorithm provided estimates of the horizontal winds and their uncertainties with a vertical resolution of about 10 m, while also accounting for the tilt of the lidar platform. The virtual tower results are compared to collocated lidar wind profiling data at the A1 site, which was located roughly 2.4 rotor diameters south of the nearest turbine. The wind speed difference between the wind profiler and the virtual tower was found to be quite sensitive to atmospheric stability and wind direction below 250 m AGL. The largest differences were observed for inflow under stable conditions, where the profiler wind speeds were observed to be about 22% lower than the virtual tower near hub height. These results suggest that there are persistent horizontal gradients in the flow upwind of the wind farm which result in biased estimates using standard ground-based lidar wind profiling methods.
{"title":"Virtual tower measurements during the American WAKE ExperimeNt (AWAKEN)","authors":"R. Newsom, R. Krishnamurthy, Duli Chand, M. Pekour, Colleen M Kaul, Donna Flynn, L. Goldberger, R. Rai, S. Wharton","doi":"10.1063/5.0206844","DOIUrl":"https://doi.org/10.1063/5.0206844","url":null,"abstract":"Dual-Doppler lidar measurements were made during the American WAKE ExperimeNt to provide height-resolved measurements of wind speed and direction at multiple locations immediately south of the leading row turbines in the King Plains wind farm in Oklahoma. These so-called virtual tower measurements were performed to characterize the inflow into the wind farm and to assess possible upwind blockage effects due to the collective action of the wind farm. The campaign was conducted from 12 November 2022 to 17 October 2023, during which time 14 unique virtual tower locations were sampled with heights ranging from 240 to 490 m AGL. The wind retrieval algorithm provided estimates of the horizontal winds and their uncertainties with a vertical resolution of about 10 m, while also accounting for the tilt of the lidar platform. The virtual tower results are compared to collocated lidar wind profiling data at the A1 site, which was located roughly 2.4 rotor diameters south of the nearest turbine. The wind speed difference between the wind profiler and the virtual tower was found to be quite sensitive to atmospheric stability and wind direction below 250 m AGL. The largest differences were observed for inflow under stable conditions, where the profiler wind speeds were observed to be about 22% lower than the virtual tower near hub height. These results suggest that there are persistent horizontal gradients in the flow upwind of the wind farm which result in biased estimates using standard ground-based lidar wind profiling methods.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":null,"pages":null},"PeriodicalIF":1.9,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846983","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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