Pub Date : 2024-01-01DOI: 10.1016/j.jksues.2021.07.009
Saleh Masoud Abdallah Altbawi , Ahmad Safawi Bin Mokhtar , Touqeer Ahmed Jumani , Ilyas Khan , Nawaf N. Hamadneh , Afrasyab Khan
Considering the superior control characteristics and increased tuning flexibility of the Fractional-Order Proportional Integral Derivative (FOPID) controller than the conventional PID regulator, this article attempts to explore its application in the optimal design of the Automatic Voltage Regulator (AVR). Since FOPID has two additional tuning parameters (µ and ʎ) than its mentioned conventional counterpart, its tuning process is comparatively difficult. To overcome the stated issue, a self-regulated off-line optimal tuning method based on the Gradient-Based Optimization (GBO) algorithm is adopted in the current study. The optimal FOPID gains are obtained by minimizing the selected Fitness Function (FF) that is chosen as Integral Time Absolute Error (ITAE) in the current study. The simulations are performed using MATLAB/SIMULINK 2018a to test and compare the performance of the proposed GBO-based optimal AVR design based on the dynamic response, stability, and robustness evaluation metrics with some of the recently published metaheuristic optimization algorithm based optimal AVR designs in the literature. The results show that the proposed AVR design provides the most optimal dynamic response and enhanced stability among the considered AVR designs, thus proves its efficacy and essence.
{"title":"Optimal design of Fractional order PID controller based Automatic voltage regulator system using gradient-based optimization algorithm","authors":"Saleh Masoud Abdallah Altbawi , Ahmad Safawi Bin Mokhtar , Touqeer Ahmed Jumani , Ilyas Khan , Nawaf N. Hamadneh , Afrasyab Khan","doi":"10.1016/j.jksues.2021.07.009","DOIUrl":"10.1016/j.jksues.2021.07.009","url":null,"abstract":"<div><p>Considering the superior control characteristics and increased tuning flexibility of the Fractional-Order Proportional Integral Derivative (FOPID) controller than the conventional PID regulator, this article attempts to explore its application in the optimal design of the Automatic Voltage Regulator (AVR). Since FOPID has two additional tuning parameters (µ and ʎ) than its mentioned conventional counterpart, its tuning process is comparatively difficult. To overcome the stated issue, a self-regulated off-line optimal tuning method based on the Gradient-Based Optimization (GBO) algorithm is adopted in the current study. The optimal FOPID gains are obtained by minimizing the selected Fitness Function (FF) that is chosen as Integral Time Absolute Error (ITAE) in the current study. The simulations are performed using MATLAB/SIMULINK 2018a to test and compare the performance of the proposed GBO-based optimal AVR design based on the dynamic response, stability, and robustness evaluation metrics with some of the recently published metaheuristic optimization algorithm based optimal AVR designs in the literature. The results show that the proposed AVR design provides the most optimal dynamic response and enhanced stability among the considered AVR designs, thus proves its efficacy and essence.</p></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"36 1","pages":"Pages 32-44"},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1018363921001082/pdfft?md5=70a0ce42567e371891f09bfdfef9bf96&pid=1-s2.0-S1018363921001082-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82205500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2021.08.002
Jonathan Aguilar , Laura Velásquez , Fredys Romero , Johan Betancour , Ainhoa Rubio-Clemente , Edwin Chica
In this work, the efficiency of two horizontal-axis hydrokinetic turbines, whose blades were designed with and without multi-element hydrofoil cross-sections, has been numerical and experimentally investigated for tip speed ratio () values ranging between 2.5 and 9.0 to compare the experimental rotor performance with numerical results. The Eppler 420 hydrofoil was used for the design of the blades applying the blade element momentum (BEM) theory. The variation of the power coefficient curve of the turbines was analyzed by using computational fluid dynamics (CFD) and experimental tests through ANSYs Fluent software with six-degrees of freedom (6-DoF) user-defined function (UDF) method and an open hydraulic channel, respectively. Numerically, for the turbine with a multi-element hydrofoil and without a multi-element (traditional) hydrofoil, maximum power coefficients () of 0.5050 and 0.419 (at a value equal to 7.129 and 6.739, respectively) were obtained. It is worth noting that a reasonable agreement between the numerical and the experimental results was achieved. In this regard, the blade with a multi-element hydrofoil has a positive influence on the hydrokinetic turbine performance; therefore, it can be used for power generation in river or marine systems.
{"title":"Numerical and experimental study of hydrofoil-flap arrangements for hydrokinetic turbine applications","authors":"Jonathan Aguilar , Laura Velásquez , Fredys Romero , Johan Betancour , Ainhoa Rubio-Clemente , Edwin Chica","doi":"10.1016/j.jksues.2021.08.002","DOIUrl":"10.1016/j.jksues.2021.08.002","url":null,"abstract":"<div><div>In this work, the efficiency of two horizontal-axis hydrokinetic turbines, whose blades were designed with and without multi-element hydrofoil cross-sections, has been numerical and experimentally investigated for tip speed ratio (<span><math><mrow><mi>λ</mi></mrow></math></span>) values ranging between 2.5 and 9.0 to compare the experimental rotor performance with numerical results. The Eppler 420 hydrofoil was used for the design of the blades applying the blade element momentum (BEM) theory. The variation of the power coefficient curve of the turbines was analyzed by using computational fluid dynamics (CFD) and experimental tests through ANSYs Fluent software with six-degrees of freedom (6-DoF) user-defined function (UDF) method and an open hydraulic channel, respectively. Numerically, for the turbine with a multi-element hydrofoil and without a multi-element (traditional) hydrofoil, maximum power coefficients (<span><math><mrow><msub><mrow><mi>C</mi></mrow><mrow><mi>Pmax</mi></mrow></msub></mrow></math></span>) of 0.5050 and 0.419 (at a <span><math><mrow><mi>λ</mi></mrow></math></span> value equal to 7.129 and 6.739, respectively) were obtained. It is worth noting that a reasonable agreement between the numerical and the experimental results was achieved. In this regard, the blade with a multi-element hydrofoil has a positive influence on the hydrokinetic turbine performance; therefore, it can be used for power generation in river or marine systems.</div></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 577-588"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84443770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2023.09.003
Mustafa Wassef Hasan
In this work, a novel disturbance rejection controller based on a nonlinear fractional order proportional integral derivative with fuzzy (NLFOPIDF) approximation and an adaptive law technique for a 160 kW two horizontal axis parts tidal turbine model is proposed. The tidal turbine system encounters gigantic unknown uncertainties with external and internal disturbances induced by fatigue forces and non-uniform operative thrust and turbulence deviations caused by the effect of wind and wave movements. The main working purpose of the tidal turbine system is to extract the maximum power generated by obtaining and tracking the optimal turbine speed. To track the optimal speed turbine, two controller loops are synthesized for the tidal turbine dynamics (outer loop) and current dynamics in the q-axis component (inner loop). The stability and convergence are verified for the outer and inner loops using a candidate Lyapunov function. An approximation fuzzy function is proposed to estimate the nonlinear dynamics of the tidal turbine system, and an adaptive technique is applied to adapt the tidal turbine system against the variation in nonlinear dynamics. The results demonstrate that the NLFOPIDF controller is superior to other works in optimal power generation and optimal turbine speed tracking. Moreover, this controller can be used to achieve the maximum power coefficients to get the optimal power generation.
{"title":"Disturbance rejection controller design based on nonlinear with fuzzy approximation technique for a tidal turbine system","authors":"Mustafa Wassef Hasan","doi":"10.1016/j.jksues.2023.09.003","DOIUrl":"10.1016/j.jksues.2023.09.003","url":null,"abstract":"<div><div>In this work, a novel disturbance rejection controller based on a nonlinear fractional order proportional integral derivative with fuzzy (NLFOPIDF) approximation and an adaptive law technique for a 160 kW two horizontal axis parts tidal turbine model is proposed. The tidal turbine system encounters gigantic unknown uncertainties with external and internal disturbances induced by fatigue forces and non-uniform operative thrust and turbulence deviations caused by the effect of wind and wave movements. The main working purpose of the tidal turbine system is to extract the maximum power generated by obtaining and tracking the optimal turbine speed. To track the optimal speed turbine, two controller loops are synthesized for the tidal turbine dynamics (outer loop) and current dynamics in the q-axis component (inner loop). The stability and convergence are verified for the outer and inner loops using a candidate Lyapunov function. An approximation fuzzy function is proposed to estimate the nonlinear dynamics of the tidal turbine system, and an adaptive technique is applied to adapt the tidal turbine system against the variation in nonlinear dynamics. The results demonstrate that the NLFOPIDF controller is superior to other works in optimal power generation and optimal turbine speed tracking. Moreover, this controller can be used to achieve the maximum power coefficients to get the optimal power generation.</div></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 566-576"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135459160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2022.11.002
Abdallah Ben Abdelkader, Youssef Mouloudi, Mohammed Amine Soumeur
Nowadays, grid power loss and power quality deterioration are causing many problems, especially for sensitive uses such as data centers, airports, healthcare, banking, insurance, and telecom. These issues must be resolved through energy continuity coverage and optimization. Dynamic voltage restorers (DVR) are generally used to mitigate network voltage disturbances and maintain a constant voltage value between load terminals for a short and limited duration due to limited energy storage facilities. However, this paper's proposed (DVR) system controlled by the adaptive-network fuzzy inference system (ANFIS) controller can compensate for prolonged power quality disturbances by integrating a hybrid renewable energy system (HRES) managed using classical Proportional Integral (PI) controller power management. This paper proposes a new (DVR) topology coupled with a hybrid renewable energy system (HRES) to exploit free and clean energy, consisting of a solar panel, a PEM fuel cell, and a battery storage device connected through DC-DC converters to a DC transmission, the obtained results from the simulation process of the proposed DVR system in the environment of MATLAB / Simulink showed the ability to eliminate sag that exceeded 0.9 pu in a period of more than 3 min and swells that exceeded 1.2 pu in a period that exceeded one minute. In comparison, the load voltage's total harmonic distortion THDv was reduced from 29% to 5%, and the source current total harmonic distortion THDi from 30.25% to 2.79%.
{"title":"Integration of renewable energy sources in the dynamic voltage restorer for improving power quality using ANFIS controller","authors":"Abdallah Ben Abdelkader, Youssef Mouloudi, Mohammed Amine Soumeur","doi":"10.1016/j.jksues.2022.11.002","DOIUrl":"10.1016/j.jksues.2022.11.002","url":null,"abstract":"<div><div>Nowadays, grid power loss and power quality deterioration are causing many problems, especially for sensitive uses such as data centers, airports, healthcare, banking, insurance, and telecom. These issues must be resolved through energy continuity coverage and optimization. Dynamic voltage restorers (DVR) are generally used to mitigate network voltage disturbances and maintain a constant voltage value between load terminals for a short and limited duration due to limited energy storage facilities. However, this paper's proposed (DVR) system controlled by the adaptive-network fuzzy inference system (ANFIS) controller can compensate for prolonged power quality disturbances by integrating a hybrid renewable energy system (HRES) managed using classical Proportional Integral (PI) controller power management. This paper proposes a new (DVR) topology coupled with a hybrid renewable energy system (HRES) to exploit free and clean energy, consisting of a solar panel, a PEM fuel cell, and a battery storage device connected through DC-DC converters to a DC transmission, the obtained results from the simulation process of the proposed DVR system in the environment of MATLAB / Simulink showed the ability to eliminate sag that exceeded 0.9 pu in a period of more than 3 min and swells that exceeded 1.2 pu in a period that exceeded one minute. In comparison, the load voltage's total harmonic distortion THDv was reduced from 29% to 5%, and the source current total harmonic distortion THDi from 30.25% to 2.79%.</div></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 539-548"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78153349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2021.11.001
Khaled M.K. Pasha , M.M. Elfawal
Many “suggested” airfoil geometries, that have the same chord length, are investigated. Each geometry is checked at two attack angel values, α, that equal 0° and 30°, and at values of Reynolds number, Re, that equal 822000, 1232300, 1643000, 2054000, and 2465000. The results of the lift and drag coefficients, CL and CD, are compared with those of the standard airfoil N6409. The airfoil geometry which consists mainly of two intersecting circular arcs exhibited relatively higher CL values. The performance of this airfoil was found to be considerably affected by the two non-dimensional radii of curvature, and . So, fifteen cases of this promising geometry were tested with different values of, and and with the different values of Re mentioned above. The results showed that, although the CL values were higher than those of the N6409 airfoil, but the CD values were large too. The case whose, and equal 0.56 and 0.83 respectively, exhibited the highest CL values for all Re and α values. To validate the results of this geometry, it was tested experimentally and numerically at α = 0, 5, 10, 15, 20, 30, and both the numerical and experimental results were in an acceptable agreement. This geometry is suitable for the wind turbine applications. Four correlations were suggested to relate the CL and CD to Re, and for α = 0° and α = 30°. When testing these correlations, the maximum deviations of the calculated CL and CD values from those of the numerical and experimental results were within the range from 9 to 13%.
{"title":"Investigating suggested airfoil geometries at air velocities that are within the natural wind speeds","authors":"Khaled M.K. Pasha , M.M. Elfawal","doi":"10.1016/j.jksues.2021.11.001","DOIUrl":"10.1016/j.jksues.2021.11.001","url":null,"abstract":"<div><div>Many “suggested” airfoil geometries, that have the same chord length, are investigated. Each geometry is checked at two attack angel values, α, that equal 0° and 30°, and at values of Reynolds number, Re, that equal 822000, 1232300, 1643000, 2054000, and 2465000. The results of the lift and drag coefficients, C<sub>L</sub> and CD, are compared with those of the standard airfoil N6409. The airfoil geometry which consists mainly of two intersecting circular arcs exhibited relatively higher C<sub>L</sub> values. The performance of this airfoil was found to be considerably affected by the two non-dimensional radii of curvature, <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>1</mn></msub></mrow></math></span> and <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>2</mn></msub></mrow></math></span>. So, fifteen cases of this promising geometry were tested with different values of, <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>1</mn></msub></mrow></math></span> and <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>2</mn></msub></mrow></math></span> and with the different values of Re mentioned above. The results showed that, although the C<sub>L</sub> values were higher than those of the N6409 airfoil, but the C<sub>D</sub> values were large too. The case whose, <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>1</mn></msub></mrow></math></span> and <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>2</mn></msub></mrow></math></span> equal 0.56 and 0.83 respectively, exhibited the highest C<sub>L</sub> values for all Re and α values. To validate the results of this geometry, it was tested experimentally and numerically at α = 0, 5, 10, 15, 20, 30, and both the numerical and experimental results were in an acceptable agreement. This geometry is suitable for the wind turbine applications. Four correlations were suggested to relate the C<sub>L</sub> and C<sub>D</sub> to Re, <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>1</mn></msub></mrow></math></span> and <span><math><mrow><msub><mover><mi>R</mi><mo>^</mo></mover><mn>2</mn></msub></mrow></math></span> for α = 0° and α = 30°. When testing these correlations, the maximum deviations of the calculated C<sub>L</sub> and C<sub>D</sub> values from those of the numerical and experimental results were within the range from 9 to 13%.</div></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 557-565"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84956516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2023.12.001
Hany A. Al-Ansary
{"title":"Energy storage: The energy transition’s dilemma","authors":"Hany A. Al-Ansary","doi":"10.1016/j.jksues.2023.12.001","DOIUrl":"10.1016/j.jksues.2023.12.001","url":null,"abstract":"","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 523-524"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139195444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The efficiency of a photovoltaic installation is determined by its performance ratio (PR). This ratio depends on many parameters including orientation, inclination, shading, losses in cables, and number and performance of panels. The topology of the installation is also of great importance. Indeed, the number and location of the converter(s) can also have a significant impact on the PR. This is why choices between a central inverter, string inverters or micro-inverters must be made so as not to degrade the PR. In the scientific literature, it is stated that a photovoltaic installation equipped with a central inverter has a PR of 70–80%. For micro-inverters in theory, it should be higher. The objective of this publication is to compare the PR of installations equipped with a central inverter and string inverters with the PR of those using micro-inverters, based on a statistical study grouping together 200 private installations spread throughout metropolitan France. For a better comparison, 100 installations will use a central inverter or string inverters and 100 other installations will use micro-inverters. For each installation, the data will be averaged over the longest possible periods.
{"title":"Performance ratio of photovoltaic installations in France: Comparison between inverters and micro-inverters","authors":"Quentin Lagarde , Bruno Beillard , Serge Mazen , Marie-Sandrine Denis , Julien Leylavergne","doi":"10.1016/j.jksues.2021.11.007","DOIUrl":"10.1016/j.jksues.2021.11.007","url":null,"abstract":"<div><div>The efficiency of a photovoltaic installation is determined by its performance ratio (PR). This ratio depends on many parameters including orientation, inclination, shading, losses in cables, and number and performance of panels. The topology of the installation is also of great importance. Indeed, the number and location of the converter(s) can also have a significant impact on the PR. This is why choices between a central inverter, string inverters or micro-inverters must be made so as not to degrade the PR. In the scientific literature, it is stated that a photovoltaic installation equipped with a central inverter has a PR of 70–80%. For micro-inverters in theory, it should be higher. The objective of this publication is to compare the PR of installations equipped with a central inverter and string inverters with the PR of those using micro-inverters, based on a statistical study grouping together 200 private installations spread throughout metropolitan France. For a better comparison, 100 installations will use a central inverter or string inverters and 100 other installations will use micro-inverters. For each installation, the data will be averaged over the longest possible periods.</div></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 531-538"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78618748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2023.09.001
S. Senthilraja , R. Gangadevi , Hasan Köten , Sivasakthivel Thangavel , M. Baskaran , Mohamed M. Awad
Electrolysis is the process used to produce hydrogen using external electrical energy. Because of less initial and operating cost, less maintenance required, and simple construction, hydrogen production via water electrolysis has gained more attention among users globally. In this current attempt, a novel solar-powered hydrogen generation system was established and tested in different operating circumstances. Throughout the study, nanofluids with concentrations of 0.05%, 0.1%, and 0.2% were utilized, and their effect on electrical performance and hydrogen production rate was examined. Compared to conventional solar panels, the usage of nanofluids resulted in a significant improvement in electrical power productivity and hydrogen output rate. The highest electrical efficiency is with a 0.2% volume fraction of CuO/water nanofluids at 13.5% at Noon. During the same period, the lowest and highest hydrogen yield rates are found for the conventional PV module and 0.2% volume fraction CuO/water nanofluids-based system as 7.9 ml/min and 18.2 ml/min, respectively.
{"title":"Energy analysis of solar powered hydrogen production system with CuO/water nanofluids: An experimental investigation","authors":"S. Senthilraja , R. Gangadevi , Hasan Köten , Sivasakthivel Thangavel , M. Baskaran , Mohamed M. Awad","doi":"10.1016/j.jksues.2023.09.001","DOIUrl":"10.1016/j.jksues.2023.09.001","url":null,"abstract":"<div><div>Electrolysis is the process used to produce hydrogen using external electrical energy. Because of less initial and operating cost, less maintenance required, and simple construction, hydrogen production via water electrolysis has gained more attention among users globally. In this current attempt, a novel solar-powered hydrogen generation system was established and tested in different operating circumstances. Throughout the study, nanofluids with concentrations of 0.05%, 0.1%, and 0.2% were utilized, and their effect on electrical performance and hydrogen production rate was examined. Compared to conventional solar panels, the usage of nanofluids resulted in a significant improvement in electrical power productivity and hydrogen output rate. The highest electrical efficiency is with a 0.2% volume fraction of CuO/water nanofluids at 13.5% at Noon. During the same period, the lowest and highest hydrogen yield rates are found for the conventional PV module and 0.2% volume fraction CuO/water nanofluids-based system as 7.9 ml/min and 18.2 ml/min, respectively.</div></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 525-530"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134918630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2023.12.002
{"title":"Acknowledgment for Reviewers","authors":"","doi":"10.1016/j.jksues.2023.12.002","DOIUrl":"10.1016/j.jksues.2023.12.002","url":null,"abstract":"","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Page 589"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143303392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-01DOI: 10.1016/j.jksues.2022.01.006
Evgeny V. Solomin
The market for small vertical axis wind turbines (VAWTs) continues to grow rapidly, filling up especially the low wind potential locations. Since the Saudi Government has announced to install 9 GW of wind power by 2032, this ambitious plan could be at least partially improved by the small wind turbines, taking into account the low annual mean wind speed on the most Kingdom of Saudi Arabia territory.
However, the safety and durability of most commercially available VAWTs have not been adequately addressed with respect to the turbine over speed in high wind speed conditions.
The presented research gives a methodology for calculating a cost-effective dynamic braking controller, based on a centrifugal mechanical activation spring-load mechanism with a pendulum. The analysis is focused on a small two-tier 3 kW Darrieus VAWT, where a mechanically activated friction brake is deployed as the turbine rotational speed approaches a red line. The proposed method makes a small turbine absolutely safe on any available wind speed and/or during accidental electric load switch off. The analysis was made for a typically high continental wind speed of 25 m/s.
The paper presents the calculation model in VisSim software. Controller parameters were developed as the result of the research conducted on a functional turbine of the specific size in the model. The experiments covered two different cases: with a relatively low spring stiffness coefficient (400 N/m), showing the periodical oscillations of a controller pendulum on the cut-out speed and a high spring stiffness coefficient (4000 N/m), which the VAWT rotor can be surely braked at.
The paper is intended to provide the mathematical basis for the scientific analysis, as well as providing practical implementation information to engineers building similar turbines, including Savonius, Darrieus, H-Darrieus, helix shape, V-type, and any other types of rotating rotors. The estimated capacity utilization factor (CUF) of any VAWTs, when using the proposed centrifugal mechanical controller, can be increased twice to 82% for on-land small VAWTs.
{"title":"Centrifugal controller of rotation frequency for vertical axis wind turbines","authors":"Evgeny V. Solomin","doi":"10.1016/j.jksues.2022.01.006","DOIUrl":"10.1016/j.jksues.2022.01.006","url":null,"abstract":"<div><div>The market for small vertical axis wind turbines (VAWTs) continues to grow rapidly, filling up especially the low wind potential locations. Since the Saudi Government has announced to install 9 GW of wind power by 2032, this ambitious plan could be at least partially improved by the small wind turbines, taking into account the low annual mean wind speed on the most Kingdom of Saudi Arabia territory.</div><div>However, the safety and durability of most commercially available VAWTs have not been adequately addressed with respect to the turbine over speed in high wind speed conditions.</div><div>The presented research gives a methodology for calculating a cost-effective dynamic braking controller, based on a centrifugal mechanical activation spring-load mechanism with a pendulum. The analysis is focused on a small two-tier 3 kW Darrieus VAWT, where a mechanically activated friction brake is deployed as the turbine rotational speed approaches a red line. The proposed method makes a small turbine absolutely safe on any available wind speed and/or during accidental electric load switch off. The analysis was made for a typically high continental wind speed of 25 m/s.</div><div>The paper presents the calculation model in VisSim software. Controller parameters were developed as the result of the research conducted on a functional turbine of the specific size in the model. The experiments covered two different cases: with a relatively low spring stiffness coefficient (400 <em>N/m</em>), showing the periodical oscillations of a controller pendulum on the cut-out speed and a high spring stiffness coefficient (4000 <em>N/m</em>), which the VAWT rotor can be surely braked at.</div><div>The paper is intended to provide the mathematical basis for the scientific analysis, as well as providing practical implementation information to engineers building similar turbines, including Savonius, Darrieus, H-Darrieus, helix shape, V-type, and any other types of rotating rotors. The estimated capacity utilization factor (CUF) of any VAWTs, when using the proposed centrifugal mechanical controller, can be increased twice to 82% for on-land small VAWTs.</div></div>","PeriodicalId":35558,"journal":{"name":"Journal of King Saud University, Engineering Sciences","volume":"35 8","pages":"Pages 549-556"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88352728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号