In this work,an oscillating-body wave energy converter(OBWEC)with a hydraulic power take-off(PTO)system named“Dolphin 1”is designed,in which the hydraulic PTO system is equivalent to a transfer station and plays a c...In this work,an oscillating-body wave energy converter(OBWEC)with a hydraulic power take-off(PTO)system named“Dolphin 1”is designed,in which the hydraulic PTO system is equivalent to a transfer station and plays a crucial role in ensuring the stability of the electrical energy output and the efficiency of the overall system.A corresponding mathematical model for the hydraulic PTO system has been established,the factors that influence its performance have been studied,and an algorithm for solving the optimal working pressure has been derived in this paper.Moreover,a PID control method to enable the hydraulic PTO system to automatically achieve optimal performance under different wave conditions has been designed.The results indicate that,compared with single-chamber hydraulic cylinders,double-chamber hydraulic cylinders have a wider application range and greater performance;the accumulator can stabilize the output power of the hydraulic PTO system and slightly increase it;excessively large or small hydraulic motor displacement hinders system performance;and each wave condition corresponds to a unique optimal working pressure for the hydraulic PTO system.In addition,the relationship between the optimal working pressure P_(m)and the pressure P_(h)of the wave force acting on the piston satisfies P_(m)^(2)=∫_(t_(1))^(t_(2))P_(h)^(2)dt/(t_(2)-t_(1)).Furthermore,adjusting the hydraulic motor displacement automatically via a PID controller ensures that the actual working pressure of the hydraulic PTO system consistently reaches or approaches its theoretically optimal value under various wave conditions,which is a very effective control method for enhancing the performance of the hydraulic PTO system.展开更多
Herein,PtO-supported GdFeO_(3)(PtO/GdFeO_(3))composite photocatalysts were synthesized by a solutionbased technique.Extensive analysis using various analytical instruments has shown that PtO plays a crucial function i...Herein,PtO-supported GdFeO_(3)(PtO/GdFeO_(3))composite photocatalysts were synthesized by a solutionbased technique.Extensive analysis using various analytical instruments has shown that PtO plays a crucial function in augmenting the visible light absorption capacity of composites.Better photogenerated charge carrier transport was credited with this improvement,which led to a decrease in bandgap energy as low as 2.14 eV.The PtO/GdFeO_(3) nanocomposites showed remarkable photocatalytic activity when exposed to visible light,especially in the conversion of CO_(2) into CH_(3)OH.After 9 h of light,a noteworthy yield of 1550μmol·g^(−1) of methanol was produced,demonstrating maximum efficiency at a dose of 2.0 g·L^(−1) and a concentration of 5.0%PtO/GdFeO_(3).This yield indicates the effectiveness of the heterostructure,which outperformed pristine GdFeO_(3) by a factor of 7.85.This significant enhancement highlights the potential advantages of the modified structure in improving performance.Most significantly,the photocatalyst's durability maintained 98.0%of its initial efficacy throughout five cycles.The success of PtO/GdFeO_(3) is largely due to the synergistic light absorption capabilities and enhanced photocharge carrier separation that the integration of PtO produced.It highlights the conversion of CO_(2) into valuable chemicals under visible light exposure,as well as the promise of mixed oxide nanostructures in ecologically responsible material creation.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.52071094 and 51979065).
文摘In this work,an oscillating-body wave energy converter(OBWEC)with a hydraulic power take-off(PTO)system named“Dolphin 1”is designed,in which the hydraulic PTO system is equivalent to a transfer station and plays a crucial role in ensuring the stability of the electrical energy output and the efficiency of the overall system.A corresponding mathematical model for the hydraulic PTO system has been established,the factors that influence its performance have been studied,and an algorithm for solving the optimal working pressure has been derived in this paper.Moreover,a PID control method to enable the hydraulic PTO system to automatically achieve optimal performance under different wave conditions has been designed.The results indicate that,compared with single-chamber hydraulic cylinders,double-chamber hydraulic cylinders have a wider application range and greater performance;the accumulator can stabilize the output power of the hydraulic PTO system and slightly increase it;excessively large or small hydraulic motor displacement hinders system performance;and each wave condition corresponds to a unique optimal working pressure for the hydraulic PTO system.In addition,the relationship between the optimal working pressure P_(m)and the pressure P_(h)of the wave force acting on the piston satisfies P_(m)^(2)=∫_(t_(1))^(t_(2))P_(h)^(2)dt/(t_(2)-t_(1)).Furthermore,adjusting the hydraulic motor displacement automatically via a PID controller ensures that the actual working pressure of the hydraulic PTO system consistently reaches or approaches its theoretically optimal value under various wave conditions,which is a very effective control method for enhancing the performance of the hydraulic PTO system.
基金support from National Natural Science Foundation of China(21771047)Natural Science Foundation of Heilongjiang Province,China(YQ2020E029)Open Project of State Key Laboratory of Inorganic Synthesis&Preparative Chemistry,Jilin University(2023-17).
文摘Herein,PtO-supported GdFeO_(3)(PtO/GdFeO_(3))composite photocatalysts were synthesized by a solutionbased technique.Extensive analysis using various analytical instruments has shown that PtO plays a crucial function in augmenting the visible light absorption capacity of composites.Better photogenerated charge carrier transport was credited with this improvement,which led to a decrease in bandgap energy as low as 2.14 eV.The PtO/GdFeO_(3) nanocomposites showed remarkable photocatalytic activity when exposed to visible light,especially in the conversion of CO_(2) into CH_(3)OH.After 9 h of light,a noteworthy yield of 1550μmol·g^(−1) of methanol was produced,demonstrating maximum efficiency at a dose of 2.0 g·L^(−1) and a concentration of 5.0%PtO/GdFeO_(3).This yield indicates the effectiveness of the heterostructure,which outperformed pristine GdFeO_(3) by a factor of 7.85.This significant enhancement highlights the potential advantages of the modified structure in improving performance.Most significantly,the photocatalyst's durability maintained 98.0%of its initial efficacy throughout five cycles.The success of PtO/GdFeO_(3) is largely due to the synergistic light absorption capabilities and enhanced photocharge carrier separation that the integration of PtO produced.It highlights the conversion of CO_(2) into valuable chemicals under visible light exposure,as well as the promise of mixed oxide nanostructures in ecologically responsible material creation.
