Optimal thermo-economic integration of renewable energy sources with multi-generation energy systems is a prime research topic today. The present study proposes a multi-criteria evaluation method of such integration, based on combined heating and power (CHP), and combined cooling and power (CCP) scenarios, for three different solar intensities. Three novel solar-driven tri-generation systems are selected. They include different organic Rankine cycle (ORC) architectures and a Kalina cycle system (KCS) and a double-effect absorption refrigeration cycle as bottoming cycles. Evaluation of the tri-generation systems, both with and without the KCS system, indicates a performance improvement of up to 23% in various thermoeconomic characteristics when the KCS system is present. Selection of the suitable tri-generation system for each condition and optimization of the working fluid are carried out based on a multi-attribute decision-making method. P-xylene is found as the optimal organic working fluid for ORC and ORC (ORC integrated with internal heat exchanger) based systems, and benzene for the regenerative ORC-based system in both CHP and CCP scenarios. Multi-criteria analysis shows that ORC-based system outperforms other systems with net outranking flow of 0.44 (0.39) for CHP (CCP) application. The optimal configuration gives 95.6 M$ and 1.99 years for net present value and dynamic payback period, and 83.03% and 34.55% for energy and exergy efficiencies, respectively.
{"title":"Multi-criteria thermo-economic analysis of solar-driven tri-generation systems equipped with organic Rankine cycle and bottoming absorption refrigeration and Kalina cycles","authors":"Masood Dehghan, Ghasem Akbari, Nader Montazerin, Arman Maroufi","doi":"10.1063/5.0167966","DOIUrl":"https://doi.org/10.1063/5.0167966","url":null,"abstract":"Optimal thermo-economic integration of renewable energy sources with multi-generation energy systems is a prime research topic today. The present study proposes a multi-criteria evaluation method of such integration, based on combined heating and power (CHP), and combined cooling and power (CCP) scenarios, for three different solar intensities. Three novel solar-driven tri-generation systems are selected. They include different organic Rankine cycle (ORC) architectures and a Kalina cycle system (KCS) and a double-effect absorption refrigeration cycle as bottoming cycles. Evaluation of the tri-generation systems, both with and without the KCS system, indicates a performance improvement of up to 23% in various thermoeconomic characteristics when the KCS system is present. Selection of the suitable tri-generation system for each condition and optimization of the working fluid are carried out based on a multi-attribute decision-making method. P-xylene is found as the optimal organic working fluid for ORC and ORC (ORC integrated with internal heat exchanger) based systems, and benzene for the regenerative ORC-based system in both CHP and CCP scenarios. Multi-criteria analysis shows that ORC-based system outperforms other systems with net outranking flow of 0.44 (0.39) for CHP (CCP) application. The optimal configuration gives 95.6 M$ and 1.99 years for net present value and dynamic payback period, and 83.03% and 34.55% for energy and exergy efficiencies, respectively.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135736766","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}
This study investigated the potential of producing and upgrading bio-oil from plastic waste through a catalytic pyrolysis process. Plastic waste samples composed of polystyrene, polyethylene, and low-density polyethylene, shredded to sizes of 1.5–2.5 mm and blended in a ratio of 50/25/25, respectively, were pyrolyzed in a fluidized bed reactor at optimal conditions of 560–650 °C, a heating rate of 15 °C/min, and N2 gas flow rate of 100 ml/min in the presence of zeolite catalysts. The produced bio-oil was treated with fossil diesel, calcium hydroxide, and sodium sulfate to enhance its properties. The results showed that bio-oil production was increased to 65 wt. %, while char was reduced to 3.5 wt. %. Treatment with 20 wt. % diesel reduced bio-oil kinematic viscosity by 58% and improved stability from 20% to 50%. The addition of 16 g calcium hydroxide reduced the bio-oil acidity by 51% from a pH of 3.2–4.85. Furthermore, the bio-oil moisture content was reduced from 10 to 5.2 wt. % through the addition of 10 g of sodium sulfate, while the lower heating value was improved to 39.0 MJ/kg. Therefore, the catalytic pyrolysis of plastic waste in a fluidized bed reactor, and the various treatments performed on the generated bio-oil proved to be an effective technique to enhance the economic value of plastic waste and its environmental management at large.
{"title":"Enhancing properties of bio-oil produced from plastic waste: A case study utilized plastic waste from Dar-es-Salaam dump sites","authors":"Erasto Hebuka, Raphael Iddphonce","doi":"10.1063/5.0167121","DOIUrl":"https://doi.org/10.1063/5.0167121","url":null,"abstract":"This study investigated the potential of producing and upgrading bio-oil from plastic waste through a catalytic pyrolysis process. Plastic waste samples composed of polystyrene, polyethylene, and low-density polyethylene, shredded to sizes of 1.5–2.5 mm and blended in a ratio of 50/25/25, respectively, were pyrolyzed in a fluidized bed reactor at optimal conditions of 560–650 °C, a heating rate of 15 °C/min, and N2 gas flow rate of 100 ml/min in the presence of zeolite catalysts. The produced bio-oil was treated with fossil diesel, calcium hydroxide, and sodium sulfate to enhance its properties. The results showed that bio-oil production was increased to 65 wt. %, while char was reduced to 3.5 wt. %. Treatment with 20 wt. % diesel reduced bio-oil kinematic viscosity by 58% and improved stability from 20% to 50%. The addition of 16 g calcium hydroxide reduced the bio-oil acidity by 51% from a pH of 3.2–4.85. Furthermore, the bio-oil moisture content was reduced from 10 to 5.2 wt. % through the addition of 10 g of sodium sulfate, while the lower heating value was improved to 39.0 MJ/kg. Therefore, the catalytic pyrolysis of plastic waste in a fluidized bed reactor, and the various treatments performed on the generated bio-oil proved to be an effective technique to enhance the economic value of plastic waste and its environmental management at large.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135736908","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}
Hongjun Wang, Qiangqiang Zhang, Xin Li, Xia Zhang, Tianzeng Ma
A solid oxide electrolysis cell require high-temperature steam. However, using electricity to generate steam is highly energy intensive, and concentrated solar power is a good substitute for it. The authors of this study propose a solar steam generator with an enhanced capacity for heat transfer by installing a porous ceramic material inside it and using spray cooling technology. Currently used steam generators produce steam at a temperature that rarely reaches 700–1000 °C. The steam generator developed here can produce steam at a temperature of up to 800 °C by using concentrated solar power. Moreover, we tested two porous silicon carbide ceramic materials for use in the generator under various experimental conditions and investigated the effects of the irradiation power, rate of flow at the inlet, and porosity of the ceramic material (ranging from 70% to 85%) on its thermal performance. The results showed that the temperature at the outlets of steam generators equipped with the two kinds of ceramic materials increased as the irradiation power was increased from 2.3 to 4.6 kW, and their thermal efficiency increased from 17% to 65.5% as the rate of flow of water at the inlet was raised from 0.92 to 4.68 L/h. The thermal efficiency of the generator equipped with the ceramic with a low porosity (70%) was approximately 26% greater than that of the generator equipped with the ceramic with a high porosity (85%) at an irradiation power of 4.2 kW. When the solar simulator was suddenly turned off, the generator with the lower porosity was more resistant to interference. The results here provide an important reference for optimizing the steam generator.
{"title":"Experimental investigation into the thermal performance of a solar steam generator based on spray cooling heat transfer and porous silicon carbide ceramic","authors":"Hongjun Wang, Qiangqiang Zhang, Xin Li, Xia Zhang, Tianzeng Ma","doi":"10.1063/5.0165174","DOIUrl":"https://doi.org/10.1063/5.0165174","url":null,"abstract":"A solid oxide electrolysis cell require high-temperature steam. However, using electricity to generate steam is highly energy intensive, and concentrated solar power is a good substitute for it. The authors of this study propose a solar steam generator with an enhanced capacity for heat transfer by installing a porous ceramic material inside it and using spray cooling technology. Currently used steam generators produce steam at a temperature that rarely reaches 700–1000 °C. The steam generator developed here can produce steam at a temperature of up to 800 °C by using concentrated solar power. Moreover, we tested two porous silicon carbide ceramic materials for use in the generator under various experimental conditions and investigated the effects of the irradiation power, rate of flow at the inlet, and porosity of the ceramic material (ranging from 70% to 85%) on its thermal performance. The results showed that the temperature at the outlets of steam generators equipped with the two kinds of ceramic materials increased as the irradiation power was increased from 2.3 to 4.6 kW, and their thermal efficiency increased from 17% to 65.5% as the rate of flow of water at the inlet was raised from 0.92 to 4.68 L/h. The thermal efficiency of the generator equipped with the ceramic with a low porosity (70%) was approximately 26% greater than that of the generator equipped with the ceramic with a high porosity (85%) at an irradiation power of 4.2 kW. When the solar simulator was suddenly turned off, the generator with the lower porosity was more resistant to interference. The results here provide an important reference for optimizing the steam generator.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347535","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 current grid code in China in regard to solar forecasting is, in my opinion, underdeveloped, especially in contrast to the rate at which photovoltaics are being installed. As such, explaining the limitations of the grid code and resetting pathways to improve it are thought utilitarian for those scientists and policymakers who are responsible for or aware of the grid code but have not themselves worked on the problem of forecasting. In this perspective article, I should first explain with respect to China's grid code the perceived deficiencies in the current forecasting research and practices, and then outline a five-stage workflow that could completely mitigate the situation. Among other things, the over-reliance on accuracy as the basis for gauging the goodness of forecasts is identified as a root cause for the status quo, and thus, I advocate a holistic forecast verification procedure that encompasses consistency, quality, and value. With that in mind, the proposed workflow for better solar forecasting for grid integration purposes relies on the effective information flow among the weather department, grid operators, and individual plant owners, which is inline with the current grid code. What goes beyond this is that the proposal further introduces a couple of concepts called “hierarchical reconciliation” and “firm forecasting,” which are new but are able to eliminate forecast errors wholly, thus making solar power dispatchable on the system level. With a slight premium incurred, it is now possible to manage solar plants, or variable renewables in general, in the same style as managing conventional fire-powered generators.
{"title":"The future of solar forecasting in China","authors":"Dazhi Yang","doi":"10.1063/5.0172315","DOIUrl":"https://doi.org/10.1063/5.0172315","url":null,"abstract":"The current grid code in China in regard to solar forecasting is, in my opinion, underdeveloped, especially in contrast to the rate at which photovoltaics are being installed. As such, explaining the limitations of the grid code and resetting pathways to improve it are thought utilitarian for those scientists and policymakers who are responsible for or aware of the grid code but have not themselves worked on the problem of forecasting. In this perspective article, I should first explain with respect to China's grid code the perceived deficiencies in the current forecasting research and practices, and then outline a five-stage workflow that could completely mitigate the situation. Among other things, the over-reliance on accuracy as the basis for gauging the goodness of forecasts is identified as a root cause for the status quo, and thus, I advocate a holistic forecast verification procedure that encompasses consistency, quality, and value. With that in mind, the proposed workflow for better solar forecasting for grid integration purposes relies on the effective information flow among the weather department, grid operators, and individual plant owners, which is inline with the current grid code. What goes beyond this is that the proposal further introduces a couple of concepts called “hierarchical reconciliation” and “firm forecasting,” which are new but are able to eliminate forecast errors wholly, thus making solar power dispatchable on the system level. With a slight premium incurred, it is now possible to manage solar plants, or variable renewables in general, in the same style as managing conventional fire-powered generators.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735664","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 continuous utilization of fossil fuel reserves and augmented pollution level leads to inevitable transition toward renewable fuel in transportation sector. Biodiesel is one of the most renowned biofuels across the energy sector in recent decade. Even though biodiesel has many advantages, the stability is a key concern on downside of biodiesel. The presence of oxygenated compounds in biodiesel leads to faster rancidation during prolonged storage period. This research focuses on producing biodiesel from diary waste and assesses the influence of synthetic antioxidant on its stability. The addition of antioxidant showed a significant increase in the induction period (IP) of biodiesel. Tert-butyl hydroquinone (TBHQ) showed superior Induction Period (IP) of 15.28 h at 110 °C, which is due to its radical suppression behavior during ageing. The thermal ageing results also confirmed the potential of the TBHQ blend with the least ageing rate of 0.08 cSt/h. The biodiesel samples showed signs of dehydration and polymerization after ageing, which is detected by FTIR spectra. Finally, the engine testing showed that antioxidant reduces dangerous NOx emission with minor sacrifice toward performance aspects. From the results, it can be seen that the biodiesel from yeast grown dairy wastewater can be a suitable competitor in the alternate fuel market.
{"title":"Effect of antioxidant addition on stability and emission aspects of novel biodiesel generated from the yeast <i>Yarrowia lipolytica</i> cultivated on dairy effluent","authors":"Srirajarajeshwari Manoharan, Jeyanthi Jeyadharmarajan","doi":"10.1063/5.0168110","DOIUrl":"https://doi.org/10.1063/5.0168110","url":null,"abstract":"The continuous utilization of fossil fuel reserves and augmented pollution level leads to inevitable transition toward renewable fuel in transportation sector. Biodiesel is one of the most renowned biofuels across the energy sector in recent decade. Even though biodiesel has many advantages, the stability is a key concern on downside of biodiesel. The presence of oxygenated compounds in biodiesel leads to faster rancidation during prolonged storage period. This research focuses on producing biodiesel from diary waste and assesses the influence of synthetic antioxidant on its stability. The addition of antioxidant showed a significant increase in the induction period (IP) of biodiesel. Tert-butyl hydroquinone (TBHQ) showed superior Induction Period (IP) of 15.28 h at 110 °C, which is due to its radical suppression behavior during ageing. The thermal ageing results also confirmed the potential of the TBHQ blend with the least ageing rate of 0.08 cSt/h. The biodiesel samples showed signs of dehydration and polymerization after ageing, which is detected by FTIR spectra. Finally, the engine testing showed that antioxidant reduces dangerous NOx emission with minor sacrifice toward performance aspects. From the results, it can be seen that the biodiesel from yeast grown dairy wastewater can be a suitable competitor in the alternate fuel market.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735679","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}
Zhao Xin-gang, Hu Shuran, Zhang Wenbin, Wang Wei, Lu Wenjie
Currently, the reform of electricity cross-subsidies on the sales side is a crucial task in the market-oriented process. The resulting electricity prices, which reflect the true value, can not only enhance resource allocation efficiency but also contribute to increased carbon emissions. Consequently, it is imperative to actively pursue carbon trading policies to address this issue. In this study, we examined the reformed electricity prices for industrial and residential users by applying the Ramsey pricing model. Moreover, a recursive dynamic computable general equilibrium model is employed to analyze the carbon emissions and economic performance of the cross-subsidy reform under different settings of the quota decline scheme, quota allocation mode, and penalty mechanism within the carbon emissions trading scheme. The results demonstrate the following findings: (1) The calculated Ramsey prices for industrial and residential users are 0.541 and 0.792 yuan/kWh, respectively. (2) Implementation of the electricity cross-subsidy reform can lead to a significant increment in CO2 emission. However, it effectively improves national economic and social development and promotes the growth of gross domestic product, industrial output, and changes in residential consumption expenditure structure. (3) Carbon trading proves to be an effective means to achieve carbon emission reduction at a lower economic cost after the reform. Notably, the degree of impact is more sensitive to the carbon decline factor.
{"title":"How does carbon trading scheme affect carbon emissions and economic performance of electricity cross-subsidy reform: A recursive dynamic CGE model in China","authors":"Zhao Xin-gang, Hu Shuran, Zhang Wenbin, Wang Wei, Lu Wenjie","doi":"10.1063/5.0157252","DOIUrl":"https://doi.org/10.1063/5.0157252","url":null,"abstract":"Currently, the reform of electricity cross-subsidies on the sales side is a crucial task in the market-oriented process. The resulting electricity prices, which reflect the true value, can not only enhance resource allocation efficiency but also contribute to increased carbon emissions. Consequently, it is imperative to actively pursue carbon trading policies to address this issue. In this study, we examined the reformed electricity prices for industrial and residential users by applying the Ramsey pricing model. Moreover, a recursive dynamic computable general equilibrium model is employed to analyze the carbon emissions and economic performance of the cross-subsidy reform under different settings of the quota decline scheme, quota allocation mode, and penalty mechanism within the carbon emissions trading scheme. The results demonstrate the following findings: (1) The calculated Ramsey prices for industrial and residential users are 0.541 and 0.792 yuan/kWh, respectively. (2) Implementation of the electricity cross-subsidy reform can lead to a significant increment in CO2 emission. However, it effectively improves national economic and social development and promotes the growth of gross domestic product, industrial output, and changes in residential consumption expenditure structure. (3) Carbon trading proves to be an effective means to achieve carbon emission reduction at a lower economic cost after the reform. Notably, the degree of impact is more sensitive to the carbon decline factor.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135347540","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}
To maximize the profitability of wind power plants, wind farms are often characterized by high wind turbine density leading to operations with reduced turbine spacing. As a consequence, the overall wind farm power capture is hindered by complex flow features associated with flow modifications induced by the various wind turbine rotors. In addition to the generation of wakes, the velocity of the incoming wind field can reduce due to the increased pressure in the proximity of a single turbine rotor (named induction); a similar effect occurs at the wind-farm level (global blockage), which can have a noticeable impact on power production. On the other hand, intra-wind-farm regions featuring increased velocity compared to the freestream (speedups) have also been observed, which can be a source for a potential power boost. To quantify these rotor-induced effects on the incoming wind velocity field, three profiling LiDARs and one scanning wind LiDAR were deployed both before and after the construction of an onshore wind turbine array. The different wind conditions are classified according to the ambient turbulence intensity and streamwise/spanwise spacing among wind turbines. The analysis of the mean velocity field reveals enhanced induction and speedup under stably stratified atmospheric conditions. Furthermore, a reduced horizontal area between adjacent turbines has a small impact on the induction zone but increases significantly the speedup between adjacent rotors.
{"title":"Blockage and speedup in the proximity of an onshore wind farm: A scanning wind LiDAR experiment","authors":"M. Puccioni, C. F. Moss, C. Jacquet, G. V. Iungo","doi":"10.1063/5.0157937","DOIUrl":"https://doi.org/10.1063/5.0157937","url":null,"abstract":"To maximize the profitability of wind power plants, wind farms are often characterized by high wind turbine density leading to operations with reduced turbine spacing. As a consequence, the overall wind farm power capture is hindered by complex flow features associated with flow modifications induced by the various wind turbine rotors. In addition to the generation of wakes, the velocity of the incoming wind field can reduce due to the increased pressure in the proximity of a single turbine rotor (named induction); a similar effect occurs at the wind-farm level (global blockage), which can have a noticeable impact on power production. On the other hand, intra-wind-farm regions featuring increased velocity compared to the freestream (speedups) have also been observed, which can be a source for a potential power boost. To quantify these rotor-induced effects on the incoming wind velocity field, three profiling LiDARs and one scanning wind LiDAR were deployed both before and after the construction of an onshore wind turbine array. The different wind conditions are classified according to the ambient turbulence intensity and streamwise/spanwise spacing among wind turbines. The analysis of the mean velocity field reveals enhanced induction and speedup under stably stratified atmospheric conditions. Furthermore, a reduced horizontal area between adjacent turbines has a small impact on the induction zone but increases significantly the speedup between adjacent rotors.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135735809","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}
Martin Träsch, Nidiana Rosado-Hau, C. Matoug, Maël Arhant, Vincent Perier, Benoît Augier, Michel Répécaud
In this paper, the 10 kW WindQuest Vertical Axis Wind Turbine (VAWT) has been instrumented by strain gauges during its trials in the Ifremer in situ test site of Brest to study the effects of the structural dynamic response of the blades under operating conditions. Static and dynamic effects have been investigated as a function of the rotational speed when the rotor operates under stable wind conditions. The analysis segregates the influence of the gravitational, inertial, and aerodynamic loading components on the flapwise bending stress of the blades. The study of the cyclic variations on the blade strain at different Tip-Speed Ratios leads to the identification of the dynamic stall effect on the unsteady loads, while the spectral analysis describes the system eigenfrequencies excited by the interaction of the wind and the structure's motion. The results provide useful data to validate numerical models for VAWT blades with similar design and evaluate the structural fatigue.
{"title":"Blade strain analysis from field measurements on a vertical axis wind turbine","authors":"Martin Träsch, Nidiana Rosado-Hau, C. Matoug, Maël Arhant, Vincent Perier, Benoît Augier, Michel Répécaud","doi":"10.1063/5.0155024","DOIUrl":"https://doi.org/10.1063/5.0155024","url":null,"abstract":"In this paper, the 10 kW WindQuest Vertical Axis Wind Turbine (VAWT) has been instrumented by strain gauges during its trials in the Ifremer in situ test site of Brest to study the effects of the structural dynamic response of the blades under operating conditions. Static and dynamic effects have been investigated as a function of the rotational speed when the rotor operates under stable wind conditions. The analysis segregates the influence of the gravitational, inertial, and aerodynamic loading components on the flapwise bending stress of the blades. The study of the cyclic variations on the blade strain at different Tip-Speed Ratios leads to the identification of the dynamic stall effect on the unsteady loads, while the spectral analysis describes the system eigenfrequencies excited by the interaction of the wind and the structure's motion. The results provide useful data to validate numerical models for VAWT blades with similar design and evaluate the structural fatigue.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":" ","pages":""},"PeriodicalIF":2.5,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46055606","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 conventional full-scale wind turbine blade testing method is unable to study the detailed structural response of blades' key subcomponents under complex loads. Therefore, developing an efficient and reliable blade subcomponent testing method is of great significance for investigating the structural characteristics of blades. This paper develops an innovative blade subcomponent test method framework, which is capable of studying the structural response under combined bending and torsion load conditions. A high-fidelity finite element model corresponding to the framework that considers nonlinear factors is established. This study further investigated the influence of boundary conditions on the results. The results showed that the test method proposed in this paper is reasonable, and the experiment based on this method is successfully conducted. The contact nonlinearity and size effects will affect the accuracy of the test results, which can be avoided by adjusting the size of the clamp.
{"title":"Development of the test method for wind turbine blade subcomponent under combined bending and torsion loads","authors":"Honghui Wu, Liangwen Qi, Naizhi Guo, Kezhong Shi, Jianzhong Xu, Qingan Li, Xiaohui Zhong","doi":"10.1063/5.0163575","DOIUrl":"https://doi.org/10.1063/5.0163575","url":null,"abstract":"The conventional full-scale wind turbine blade testing method is unable to study the detailed structural response of blades' key subcomponents under complex loads. Therefore, developing an efficient and reliable blade subcomponent testing method is of great significance for investigating the structural characteristics of blades. This paper develops an innovative blade subcomponent test method framework, which is capable of studying the structural response under combined bending and torsion load conditions. A high-fidelity finite element model corresponding to the framework that considers nonlinear factors is established. This study further investigated the influence of boundary conditions on the results. The results showed that the test method proposed in this paper is reasonable, and the experiment based on this method is successfully conducted. The contact nonlinearity and size effects will affect the accuracy of the test results, which can be avoided by adjusting the size of the clamp.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135691462","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}
Accurate airfoil lift and drag data at low Reynolds number, Re, and high angles of attack, α, are needed to analyze the performance of small wind turbines, particularly their starting. In the current study, the steady and unsteady aerodynamic characteristics of circular arc airfoils (CAAs) with and without spars, as used in water-pumping windmills, were examined in a wind tunnel of 1 m2 cross section at Re<106. The tunnel was configured as an open jet and a closed section. The effects of varying geometrical characteristics on the CAA performance were investigated using a combination of thickness, camber, aspect ratio, and airfoil chord-to-tunnel height ratio. Using force transducers, the aerodynamic forces acting on the airfoils were measured directly for both increasing and decreasing α. The decreasing α measurements produce a higher lift–drag ratio than the increasing measurements, mostly in the post-stall region. In addition, “second stall,” was observed at large α in both the open and closed tunnels depending on the Re and tunnel blockage, but was much more prominent in the closed tunnel due to its wall constraining the wake and preventing the flow from switching from one regime to another. It was shown that the performance of all tested airfoils was sensitive to low Re under steady and unsteady conditions. The latter measurements for an airfoil oscillated at reduced frequencies, k≤0.06, are the first for CAAs. Results from this investigation provide a comprehensive airfoil dataset for the accurate blade element theory modeling of CAAs aerodynamic and starting performances.
{"title":"Steady and unsteady characteristics of circular arc airfoils for water pumping windmills","authors":"I. H. John, D. H. Wood","doi":"10.1063/5.0157096","DOIUrl":"https://doi.org/10.1063/5.0157096","url":null,"abstract":"Accurate airfoil lift and drag data at low Reynolds number, Re, and high angles of attack, α, are needed to analyze the performance of small wind turbines, particularly their starting. In the current study, the steady and unsteady aerodynamic characteristics of circular arc airfoils (CAAs) with and without spars, as used in water-pumping windmills, were examined in a wind tunnel of 1 m2 cross section at Re&lt;106. The tunnel was configured as an open jet and a closed section. The effects of varying geometrical characteristics on the CAA performance were investigated using a combination of thickness, camber, aspect ratio, and airfoil chord-to-tunnel height ratio. Using force transducers, the aerodynamic forces acting on the airfoils were measured directly for both increasing and decreasing α. The decreasing α measurements produce a higher lift–drag ratio than the increasing measurements, mostly in the post-stall region. In addition, “second stall,” was observed at large α in both the open and closed tunnels depending on the Re and tunnel blockage, but was much more prominent in the closed tunnel due to its wall constraining the wake and preventing the flow from switching from one regime to another. It was shown that the performance of all tested airfoils was sensitive to low Re under steady and unsteady conditions. The latter measurements for an airfoil oscillated at reduced frequencies, k≤0.06, are the first for CAAs. Results from this investigation provide a comprehensive airfoil dataset for the accurate blade element theory modeling of CAAs aerodynamic and starting performances.","PeriodicalId":16953,"journal":{"name":"Journal of Renewable and Sustainable Energy","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135348823","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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