To improve the reliability of an aero-engine main fuel system, the quantitative and qualitative reliability analysis of the system is conducted based on goal oriented(GO) methodology. The quantitative reliability anal...To improve the reliability of an aero-engine main fuel system, the quantitative and qualitative reliability analysis of the system is conducted based on goal oriented(GO) methodology. The quantitative reliability analysis results and the minimum cut sets of the fuel system are obtained, respectively. These results are compared with the results of the FTA(Fault Tree Analysis) method, and the comparison result shows GO method is rational and applicable. Therefore, it is feasible to apply the GO method in the reliability analysis of an aero-engine main fuel system.展开更多
The intricate balance between reactor economics and safety necessitates the emergence of new and advanced nuclear systems and,very importantly,advanced materials,which can overcome current shortcomings and bring about...The intricate balance between reactor economics and safety necessitates the emergence of new and advanced nuclear systems and,very importantly,advanced materials,which can overcome current shortcomings and bring about more economic nuclear systems with designed-in inherent safety features.These advances will achieve greater safety and better nuclear reactor economics by reaching longer reactor lives with higher levels neutron irradiation,and by providing higher operation temperatures and resistance to more aggressive corrosive environments.This paper provides a review of the current state of research and development on innovative nuclear fuel materials design and development which have the potential of benefiting simultaneously reactor economics and safety.Our discussion focuses on three areas of research:Accident-tolerant Fuels(ATFs),Oxidation Dispersion Strengthened(ODS)steels and High Entropy Alloys(HEAs).The paper also gives a prospective description of future research activities on these materials.展开更多
The development of China’s aviation industry is accelerating,especially in terms of national political protection,military security and economic security.In the aviation industry’s aviation fuel system management,sa...The development of China’s aviation industry is accelerating,especially in terms of national political protection,military security and economic security.In the aviation industry’s aviation fuel system management,safety management is an important content.This paper focuses on the safety management of aviation fuel systems.展开更多
Fuel and fuel quantity parameters provide important information for aircraft safe flight. The oil quantity measurement system is an important part of aircraft fuel test. Aiming at the high precision requirement of oil...Fuel and fuel quantity parameters provide important information for aircraft safe flight. The oil quantity measurement system is an important part of aircraft fuel test. Aiming at the high precision requirement of oil quantity measurement in aircraft ground fuel test, the oil quantity measurement system based on computer test is designed, which verifies the feasibility and rationality of the design scheme and control algorithm of the oil quantity measurement software, and saves a lot of time and manpower.展开更多
Microbial contamination and the resulting corrosion in aircraft fuel system pose a serious threat to flight safety.Revealing the corrosion behavior and mechanism of fuel-degrading microorganisms on tank materials is c...Microbial contamination and the resulting corrosion in aircraft fuel system pose a serious threat to flight safety.Revealing the corrosion behavior and mechanism of fuel-degrading microorganisms on tank materials is crucial for developing effective mitigation strategies.In this study,the corrosion mechanisms of two representative hydrocarbon-degrading bacteria,Alcanivorax dieselolei and Microbacterium oxydans,toward AA7075 aluminum alloy,were systematically investigated.A combination of biofilm characterization,electrochemical testing,and surface/corrosion product characterization was employed.Both strains markedly accelerated the corrosion of AA7075,as evidence by the progressive decrease in polarization resistance and the pronounced rightward shift of the potentiodynamic polarization curves.Moreover,the difference between the pitting potential(E_(pit))and the corrosion potential(E_(corr))(ΔE=E_(pit)‒E_(corr))decreased due to microbial activities,indicating a pronounced tendency toward accelerated pitting corrosion.Corrosion morphology analysis revealed that both microbes promoted localized pitting corrosion.Furthermore,analysis of aviation kerosene composition indicated that both bacteria accelerated the degradation of C8 and C9 alkanes.These findings highlight the multiple threats of microbial contamination,material degradation,and fuel quality deterioration in fuel systems and underscore the need for targeted protection strategies for marine aviation operations.展开更多
Modern aircraft tend to use fuel thermal management systems to cool onboard heat sources.However,the design of heat transfer architectures for fuel thermal management systems relies on the experience of the engineers ...Modern aircraft tend to use fuel thermal management systems to cool onboard heat sources.However,the design of heat transfer architectures for fuel thermal management systems relies on the experience of the engineers and lacks theoretical guidance.This paper proposes a concise graph representation method based on graph theory for fuel thermal management systems,which can represent all possible connections between subsystems.A generalized optimization algorithm is proposed for fuel thermal management system architecture to minimize the heat sink.This algorithm can autonomously arrange subsystems with heat production differences and efficiently utilize the architecture of the fuel heat sink.At the same time,two evaluation indices are proposed from the perspective of subsystems.These indices intuitively and clearly show that the reason for the high efficiency of heat sink utilization is the balanced and moderate cooling of each subsystem and verify the rationality of the architecture optimization method.A set of simulations are also conducted,which demonstrate that the fuel tank temperature has no effect on the performance of the architecture.This paper provides a reference for the architectural design of aircraft fuel thermal management systems.The metrics used in this paper can also be utilized to evaluate the existing architecture.展开更多
Proton exchange membrane fuel cells (PEMFCs) provide an appealing sustainable energy system,with the solid-electrolyte membrane playing a crucial role in its overall performance.Currently,sulfonated poly(1,4-phenylene...Proton exchange membrane fuel cells (PEMFCs) provide an appealing sustainable energy system,with the solid-electrolyte membrane playing a crucial role in its overall performance.Currently,sulfonated poly(1,4-phenylene ether-ether sulfone)(SPEES),an aromatic hydrocarbon polymer,has garnered considerable attention as an alternative to Nafion polymers.However,the long-term durability and stability of SPEES present a significant challenge.In this context,we introduce a potential solution in the form of an additive,specifically a core–shell-based amine-functionalized iron titanate (A–Fe_(2)TiO_(5)),which holds promise for improving the lifetime,proton conductivity,and power density of SPEES in PEMFCs.The modified SPEES/A–Fe_(2)TiO_(5)composite membranes exhibited notable characteristics,including high water uptake,enhanced thermomechanical stability,and oxidative stability.Notably,the SPEES membrane loaded with 1.2 wt%of A–Fe_(2)TiO_(5)demonstrates a maximum proton conductivity of 155 mS ccm^(-1),a twofold increase compared to the SPEES membrane,at 80°C under 100%relative humidity (RH).Furthermore,the 1.2 wt%of A–Fe_(2)TiO_(5)/SPEES composite membranes exhibited a maximum power density of 397.37 mW cm^(-2)and a current density of 1148 mA cm^(-2)at 60°C under 100%RH,with an opencircuit voltage decay of 0.05 m V/h during 103 h of continuous operation.This study offers significant insights into the development and understanding of innovative SPEES nanocomposite membranes for PEMFC applications.展开更多
When the proton exchange membrane fuel cell(PEMFC)system is running,there will be a condition that does not require power output for a short time.In order to achieve zero power output under low power consumption,it is...When the proton exchange membrane fuel cell(PEMFC)system is running,there will be a condition that does not require power output for a short time.In order to achieve zero power output under low power consumption,it is necessary to consider the diversity of control targets and the complexity of dynamic models,which brings the challenge of high-precision tracking control of the stack output power and cathode intake flow.For system idle speed control,a modelbased nonlinear control framework is constructed in this paper.Firstly,the nonlinear dynamic model of output power and cathode intake flow is derived.Secondly,a control scheme combining nonlinear extended Kalman filter observer and state feedback controller is designed.Finally,the control scheme is verified on the PEMFC experimental platform and compared with the proportion-integration-differentiation(PID)controller.The experimental results show that the control strategy proposed in this paper can realize the idle speed control of the fuel cell system and achieve the purpose of zero power output.Compared with PID controller,it has faster response speed and better system dynamics.展开更多
Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provid...Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.展开更多
Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied p...Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.展开更多
Metok,located in Nyingchi,the Xizang Autonomous Region,is known as the last county in China to be connected by road.Poor transportation and limited access to petroleum were two obstacles to its development.As soon as ...Metok,located in Nyingchi,the Xizang Autonomous Region,is known as the last county in China to be connected by road.Poor transportation and limited access to petroleum were two obstacles to its development.As soon as the highway connecting Metok and the outside world was completed in 2014,China National Petroleum Corporation’s(CNPC)first gas station in the county was put into operation,providing the momentum for this"secret land of Lotus"and helping it embark on a journey toward openness and prosperity.展开更多
Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in lo...Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in long-distance and miniaturized environments.Fuel-driven actuators offer a promising solution by enabling the conversion of chemical energy into mechanical energy,supporting selfsustaining operations.Chemical energy from fuel can be converted into mechanical energy either directly or indirectly through methods such as electron transfer-induced charge injection,structural changes,fuel-to-electricity conversion,fuel combustioninduced heat,or fuel-induced pneumatic actuation.This paper provides a comprehensive review of recent developments in fuel-powered actuators,covering their fundamental principles,advancements,and challenges.It concludes with an outlook for miniaturized and autonomous robots,highlighting the great potential of integrating fuel-powered actuators.展开更多
Inorganic materials can solve transportable and on-site hydrolytic hydrogen generation issues.CaH_(2)/(Al/Si)composites are preferable due to their notable chemical properties.However,these composites require pretreat...Inorganic materials can solve transportable and on-site hydrolytic hydrogen generation issues.CaH_(2)/(Al/Si)composites are preferable due to their notable chemical properties.However,these composites require pretreatments,an inert environment,and long hours of physical ball milling for high homogeneity and synergistic effects.CaH_(2)also inhibits the hydrolysis reaction by forming its products on the Al/Si surface,which hinders the direct utilization of composites.This work represents the first investigation of NaH-CaH_(2)(Al/Si)fuel composites,which greatly overcome these limitations and can be directly used for on-site hydrogen generation and proton exchange membrane(PEM)fuel cells.The NaH-CaH_(2)(Al/Si)fuel composites were prepared by using a straightforward mixing method with variable composition ratios,showing high H_(2)yield and fuel cell(FC)performance.NaH addition provides the bridge effect,which opens up a new way to enable efficient hydrolysis and greatly enhances the hydrolysis activity of CaH_(2)/(Al/Si)composites.The novel fuel composites(NaH-CaH_(2)/Al)have extraordinary FC performance and a 0.42 W/cm2 peak power density greater than commercial hydrogen generators.It provides high H_(2)yield 84.4%for NaH-CaH_(2)/Al and 82%for NaH-CaH_(2)/Si compared to NaOH-CaH_(2)(Al/Si),NaCl-CaH_(2)(Al/Si),and KCl-CaH_(2)(Al/Si)composites.The NaH bridge effect hinders the direct water contact and stops the formation of Ca(OH)2 around Al/Si,which provides adequate pathways for the CaH_(2)(Al/Si)hydrolysis.The impressive capabilities of novel fuel composites are anticipated to offer practical uses in fuel cells,automobile applications,and portable/on-board H_(2)generation.展开更多
Covalent organic framework ionomers enable synergistic efficient transport of protons and oxygen in medium-temperature proton exchange membrane fuel cells Proton exchange membrane fuel cells(PEMFCs),as clean and effic...Covalent organic framework ionomers enable synergistic efficient transport of protons and oxygen in medium-temperature proton exchange membrane fuel cells Proton exchange membrane fuel cells(PEMFCs),as clean and efficient energy technologies,are constrained in their performance enhancement by the sluggish oxygen reduction reaction(ORR)kinetics at the cathode,anode CO poisoning(e.g.,from methanol crossover)and intricate water management dilemmas[1].展开更多
Photocatalytic fuel cells provide promising opportunities for sustainable wastewater treatment and energy conversion.However,their applications are challenged by the sluggish oxygen reducton reaction(ORR)kinetics at c...Photocatalytic fuel cells provide promising opportunities for sustainable wastewater treatment and energy conversion.However,their applications are challenged by the sluggish oxygen reducton reaction(ORR)kinetics at cathodes owning to the low O_(2) solubility and diffusion rate.Herein,we proposed a photobiocatalytic fuel cell(PBFC) with a novel hybrid biocathode based on artificially engineered algal cells coated by ZIF-8 confined carbon dots/bilirubin oxidase(ZIF-8/CDs/BOD@algae).Microalgae absorbed CO_(2) and provided O_(2) in situ for BOD catalysts.Due to effective absorption of O_(2) by imidazole and confinement of hydrophobic porous ZIF-8,oxygen diffusion has been accelerated in MOF/enzyme systems.Importantly,the introduction of CDs alleviated the poor conductivity of ZIF-8 and improved the electron transfer rate of BOD.Thus,the biocathode exhibited a high current density of 1767 μA/cm^(2),a 2.26-fold increase compared with that of CDs/BOD/algae biocathode.Also,it displayed enduring operational stability for up to 60 h since the firmly wrapped ZIF-8 shells could encapsulate proteins and protect algae from the external stimulation.When coupled with Mo:BiVO_(4) photoanodes,the PBFC exhibited a remarkable power output of 131.8 μW/cm^(2) using tetracycline hydrochloride(TCH) as a fuel and an increased degradation rate of TCH.Therefore,this work not only establishs an effective confinement strategy for enzyme to enrich oxygen,but also unveils new possibilities for modified microalgal cells aiding photoelectrocatalytic systems to recover energy from wastewater treatment.展开更多
To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains i...To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains in a subcritical state during routine,normal,and accidental transport conditions.In the event of an accident,the rods within the storage tank may become rearranged,introducing uncertainty that must be accounted for to ensure that criticality analysis results are conservative.Historically,this uncertainty was addressed overly conservatively due to limited research on non-uniform arrangement scenarios,which proved unsuitable for criticality safety analysis of spent fuel packages.This paper introduced three distinct methods to non-uniformly rearrange fuel rods—Uniform Arrangement by Blocks,Layer-by-Layer Determination,and Birdcage Deformation—and meticulously evaluates the influences of rod rearrangement on the effective multiplication factor of neutrons,k eff,utilizing the Monte Carlo method.Ultimately,this study presents a holistic method capable of encompassing the entire spectrum of potential effects stemming from the rearrangement of fuel rods during rods mispositioning accident.By augmenting the safety margin,this approach proves to be adeptly suited for the criticality safety analysis of nuclear fuel transport containers.展开更多
The proton exchange membrane fuel cell(PEMFC)and the hydrogen hybrid power system are studied by the fuzzy-PID(FPID)controlmethod and the fuzzy-PID controlmethod by Artificial Bee Colony algorithm(ABCFPID),respectivel...The proton exchange membrane fuel cell(PEMFC)and the hydrogen hybrid power system are studied by the fuzzy-PID(FPID)controlmethod and the fuzzy-PID controlmethod by Artificial Bee Colony algorithm(ABCFPID),respectively.The results reveal that compared with the FPID control method,the temperature overshoot of the PEMFC stack under the ABC-FPID control method is decreased by 0.6%.Moreover,the circulating water flow rate within the full operating envelope(about 3 min)is reduced by 19.46 L,which means the ABC-FPID control method is more effective in regulating the stack temperature.Then,the ABC-FPID control method is proposed to study the hydrogen hybrid power system,and the system output power matching,operating characteristic curve of the fuel cell,state of charge(SOC)of the lithium battery,system efficiency and hydrogen demand are obtained.The results indicate that the maximum system efficiency reaches 46.3%,the average system efficiency is 33.8%,and the average hydrogen demand is 0.192 kg/s.Overall,the ABC-FPID control method can efficiently ensure the stability of the fuel cell’s output power,and actively prompt the lithium battery to fulfill the function of“peak shaving and valley filling”under variable load power conditions.展开更多
This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0...This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.展开更多
基金the Shenyang Engine Research Institute,Aero Engine Corporation of China(No.A0920132002)
文摘To improve the reliability of an aero-engine main fuel system, the quantitative and qualitative reliability analysis of the system is conducted based on goal oriented(GO) methodology. The quantitative reliability analysis results and the minimum cut sets of the fuel system are obtained, respectively. These results are compared with the results of the FTA(Fault Tree Analysis) method, and the comparison result shows GO method is rational and applicable. Therefore, it is feasible to apply the GO method in the reliability analysis of an aero-engine main fuel system.
文摘The intricate balance between reactor economics and safety necessitates the emergence of new and advanced nuclear systems and,very importantly,advanced materials,which can overcome current shortcomings and bring about more economic nuclear systems with designed-in inherent safety features.These advances will achieve greater safety and better nuclear reactor economics by reaching longer reactor lives with higher levels neutron irradiation,and by providing higher operation temperatures and resistance to more aggressive corrosive environments.This paper provides a review of the current state of research and development on innovative nuclear fuel materials design and development which have the potential of benefiting simultaneously reactor economics and safety.Our discussion focuses on three areas of research:Accident-tolerant Fuels(ATFs),Oxidation Dispersion Strengthened(ODS)steels and High Entropy Alloys(HEAs).The paper also gives a prospective description of future research activities on these materials.
文摘The development of China’s aviation industry is accelerating,especially in terms of national political protection,military security and economic security.In the aviation industry’s aviation fuel system management,safety management is an important content.This paper focuses on the safety management of aviation fuel systems.
文摘Fuel and fuel quantity parameters provide important information for aircraft safe flight. The oil quantity measurement system is an important part of aircraft fuel test. Aiming at the high precision requirement of oil quantity measurement in aircraft ground fuel test, the oil quantity measurement system based on computer test is designed, which verifies the feasibility and rationality of the design scheme and control algorithm of the oil quantity measurement software, and saves a lot of time and manpower.
基金financially supported by the National Natural Science Foundation of China (No. 52371056)the Liaoning Provincial Youth Science Fund Project, China (Category B, No. 2025JH6/101000010)+1 种基金the Guangdong Basic and Applied Basic Research Foundation, China (No. 2024A1515240055)funding from the China Scholarship Council
文摘Microbial contamination and the resulting corrosion in aircraft fuel system pose a serious threat to flight safety.Revealing the corrosion behavior and mechanism of fuel-degrading microorganisms on tank materials is crucial for developing effective mitigation strategies.In this study,the corrosion mechanisms of two representative hydrocarbon-degrading bacteria,Alcanivorax dieselolei and Microbacterium oxydans,toward AA7075 aluminum alloy,were systematically investigated.A combination of biofilm characterization,electrochemical testing,and surface/corrosion product characterization was employed.Both strains markedly accelerated the corrosion of AA7075,as evidence by the progressive decrease in polarization resistance and the pronounced rightward shift of the potentiodynamic polarization curves.Moreover,the difference between the pitting potential(E_(pit))and the corrosion potential(E_(corr))(ΔE=E_(pit)‒E_(corr))decreased due to microbial activities,indicating a pronounced tendency toward accelerated pitting corrosion.Corrosion morphology analysis revealed that both microbes promoted localized pitting corrosion.Furthermore,analysis of aviation kerosene composition indicated that both bacteria accelerated the degradation of C8 and C9 alkanes.These findings highlight the multiple threats of microbial contamination,material degradation,and fuel quality deterioration in fuel systems and underscore the need for targeted protection strategies for marine aviation operations.
文摘Modern aircraft tend to use fuel thermal management systems to cool onboard heat sources.However,the design of heat transfer architectures for fuel thermal management systems relies on the experience of the engineers and lacks theoretical guidance.This paper proposes a concise graph representation method based on graph theory for fuel thermal management systems,which can represent all possible connections between subsystems.A generalized optimization algorithm is proposed for fuel thermal management system architecture to minimize the heat sink.This algorithm can autonomously arrange subsystems with heat production differences and efficiently utilize the architecture of the fuel heat sink.At the same time,two evaluation indices are proposed from the perspective of subsystems.These indices intuitively and clearly show that the reason for the high efficiency of heat sink utilization is the balanced and moderate cooling of each subsystem and verify the rationality of the architecture optimization method.A set of simulations are also conducted,which demonstrate that the fuel tank temperature has no effect on the performance of the architecture.This paper provides a reference for the architectural design of aircraft fuel thermal management systems.The metrics used in this paper can also be utilized to evaluate the existing architecture.
基金BK21 FOUR Program by Jeonbuk National University Research Grantsupported by “Regional Innovation Strategy (RIS)” through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (MOE)(2023RIS-008)H2KOREA funded by the Ministry of Education(2024 Hydrogen Industry-002, Innovative Human Resources Development Project for Hydrogen Industry)。
文摘Proton exchange membrane fuel cells (PEMFCs) provide an appealing sustainable energy system,with the solid-electrolyte membrane playing a crucial role in its overall performance.Currently,sulfonated poly(1,4-phenylene ether-ether sulfone)(SPEES),an aromatic hydrocarbon polymer,has garnered considerable attention as an alternative to Nafion polymers.However,the long-term durability and stability of SPEES present a significant challenge.In this context,we introduce a potential solution in the form of an additive,specifically a core–shell-based amine-functionalized iron titanate (A–Fe_(2)TiO_(5)),which holds promise for improving the lifetime,proton conductivity,and power density of SPEES in PEMFCs.The modified SPEES/A–Fe_(2)TiO_(5)composite membranes exhibited notable characteristics,including high water uptake,enhanced thermomechanical stability,and oxidative stability.Notably,the SPEES membrane loaded with 1.2 wt%of A–Fe_(2)TiO_(5)demonstrates a maximum proton conductivity of 155 mS ccm^(-1),a twofold increase compared to the SPEES membrane,at 80°C under 100%relative humidity (RH).Furthermore,the 1.2 wt%of A–Fe_(2)TiO_(5)/SPEES composite membranes exhibited a maximum power density of 397.37 mW cm^(-2)and a current density of 1148 mA cm^(-2)at 60°C under 100%RH,with an opencircuit voltage decay of 0.05 m V/h during 103 h of continuous operation.This study offers significant insights into the development and understanding of innovative SPEES nanocomposite membranes for PEMFC applications.
基金Supported by the Major Science and Technology Projects in Jilin Province and Changchun City(20220301010GX).
文摘When the proton exchange membrane fuel cell(PEMFC)system is running,there will be a condition that does not require power output for a short time.In order to achieve zero power output under low power consumption,it is necessary to consider the diversity of control targets and the complexity of dynamic models,which brings the challenge of high-precision tracking control of the stack output power and cathode intake flow.For system idle speed control,a modelbased nonlinear control framework is constructed in this paper.Firstly,the nonlinear dynamic model of output power and cathode intake flow is derived.Secondly,a control scheme combining nonlinear extended Kalman filter observer and state feedback controller is designed.Finally,the control scheme is verified on the PEMFC experimental platform and compared with the proportion-integration-differentiation(PID)controller.The experimental results show that the control strategy proposed in this paper can realize the idle speed control of the fuel cell system and achieve the purpose of zero power output.Compared with PID controller,it has faster response speed and better system dynamics.
基金Support by National Natural Science Foundation of China(22127802,22573091)the HY Action(62402010305)。
文摘Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.
基金supported by grants from the Natural Science Foundation of China(22362031 and 21805121)the Science and Technology Project of Yunnan Province(2019FD137)。
文摘Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.
文摘Metok,located in Nyingchi,the Xizang Autonomous Region,is known as the last county in China to be connected by road.Poor transportation and limited access to petroleum were two obstacles to its development.As soon as the highway connecting Metok and the outside world was completed in 2014,China National Petroleum Corporation’s(CNPC)first gas station in the county was put into operation,providing the momentum for this"secret land of Lotus"and helping it embark on a journey toward openness and prosperity.
基金Financial support from the program of the National Natural Science Foundation of China(Grant no.52475059)Major Program of National Natural Science Founda-tion of China(NSFC)for Basic Theory and Key Technology of Tri-Co Robots(92248301)+3 种基金the Postdoctoral Research Foundation of China(No.2024M751167)the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)Jiangsu Province Natural Science Foundation(No.BK20240155)supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Science and ICT(RS2024-00406534,RS-2025-25442809)。
文摘Soft actuators,capable of producing mechanical work in response to external stimuli,have potential applications in robotics and exoskeletons.However,they face major challenges related to energy supply,especially in long-distance and miniaturized environments.Fuel-driven actuators offer a promising solution by enabling the conversion of chemical energy into mechanical energy,supporting selfsustaining operations.Chemical energy from fuel can be converted into mechanical energy either directly or indirectly through methods such as electron transfer-induced charge injection,structural changes,fuel-to-electricity conversion,fuel combustioninduced heat,or fuel-induced pneumatic actuation.This paper provides a comprehensive review of recent developments in fuel-powered actuators,covering their fundamental principles,advancements,and challenges.It concludes with an outlook for miniaturized and autonomous robots,highlighting the great potential of integrating fuel-powered actuators.
基金financial support granted by the National Natural Science Foundation of China (No. 22402225)the Gusu Innovation and Entrepreneurship Leading Talent Plan(No. ZXL2023193)+2 种基金the Sinano Talents Plan (No. 2022000175)the Guangdong Basic and Applied Basic Research Foundation (No.2023A1515111133)the ANSO Scholarship for Young Talents
文摘Inorganic materials can solve transportable and on-site hydrolytic hydrogen generation issues.CaH_(2)/(Al/Si)composites are preferable due to their notable chemical properties.However,these composites require pretreatments,an inert environment,and long hours of physical ball milling for high homogeneity and synergistic effects.CaH_(2)also inhibits the hydrolysis reaction by forming its products on the Al/Si surface,which hinders the direct utilization of composites.This work represents the first investigation of NaH-CaH_(2)(Al/Si)fuel composites,which greatly overcome these limitations and can be directly used for on-site hydrogen generation and proton exchange membrane(PEM)fuel cells.The NaH-CaH_(2)(Al/Si)fuel composites were prepared by using a straightforward mixing method with variable composition ratios,showing high H_(2)yield and fuel cell(FC)performance.NaH addition provides the bridge effect,which opens up a new way to enable efficient hydrolysis and greatly enhances the hydrolysis activity of CaH_(2)/(Al/Si)composites.The novel fuel composites(NaH-CaH_(2)/Al)have extraordinary FC performance and a 0.42 W/cm2 peak power density greater than commercial hydrogen generators.It provides high H_(2)yield 84.4%for NaH-CaH_(2)/Al and 82%for NaH-CaH_(2)/Si compared to NaOH-CaH_(2)(Al/Si),NaCl-CaH_(2)(Al/Si),and KCl-CaH_(2)(Al/Si)composites.The NaH bridge effect hinders the direct water contact and stops the formation of Ca(OH)2 around Al/Si,which provides adequate pathways for the CaH_(2)(Al/Si)hydrolysis.The impressive capabilities of novel fuel composites are anticipated to offer practical uses in fuel cells,automobile applications,and portable/on-board H_(2)generation.
文摘Covalent organic framework ionomers enable synergistic efficient transport of protons and oxygen in medium-temperature proton exchange membrane fuel cells Proton exchange membrane fuel cells(PEMFCs),as clean and efficient energy technologies,are constrained in their performance enhancement by the sluggish oxygen reduction reaction(ORR)kinetics at the cathode,anode CO poisoning(e.g.,from methanol crossover)and intricate water management dilemmas[1].
基金support from National Natural Science Foundation of China (Nos.22176086,52100014)Natural Science Foundation of Jiangsu Province (No.BK20210189)+7 种基金State Key laboratory of Pollution Control and Resource Reuse,the Fundamental Research Funds for the Central Universities (Nos.021114380183,021114380189,021114380199)the Research Funds from Frontiers Science Center for Critical Earth Material Cycling of Nanjing UniversityResearch Funds for Jiangsu Distinguished ProfessorCarbon Peaking and Carbon Neutrality Technological Innovation Foundation of Jiangsu Province (No.BE2022861)the Central Universities - Cemac “Geo X” Interdisciplinary Program (No.021114380217)Frontiers Science Center for Critical Earth Material Cycling of Nanjing University (No.2024QNXZ07)Postdoctoral Fellowship Program of CPSF (No.GZC20231105)the Jiangsu Funding Program for Excellent Postdoctoral Talent (No.2023ZB226)。
文摘Photocatalytic fuel cells provide promising opportunities for sustainable wastewater treatment and energy conversion.However,their applications are challenged by the sluggish oxygen reducton reaction(ORR)kinetics at cathodes owning to the low O_(2) solubility and diffusion rate.Herein,we proposed a photobiocatalytic fuel cell(PBFC) with a novel hybrid biocathode based on artificially engineered algal cells coated by ZIF-8 confined carbon dots/bilirubin oxidase(ZIF-8/CDs/BOD@algae).Microalgae absorbed CO_(2) and provided O_(2) in situ for BOD catalysts.Due to effective absorption of O_(2) by imidazole and confinement of hydrophobic porous ZIF-8,oxygen diffusion has been accelerated in MOF/enzyme systems.Importantly,the introduction of CDs alleviated the poor conductivity of ZIF-8 and improved the electron transfer rate of BOD.Thus,the biocathode exhibited a high current density of 1767 μA/cm^(2),a 2.26-fold increase compared with that of CDs/BOD/algae biocathode.Also,it displayed enduring operational stability for up to 60 h since the firmly wrapped ZIF-8 shells could encapsulate proteins and protect algae from the external stimulation.When coupled with Mo:BiVO_(4) photoanodes,the PBFC exhibited a remarkable power output of 131.8 μW/cm^(2) using tetracycline hydrochloride(TCH) as a fuel and an increased degradation rate of TCH.Therefore,this work not only establishs an effective confinement strategy for enzyme to enrich oxygen,but also unveils new possibilities for modified microalgal cells aiding photoelectrocatalytic systems to recover energy from wastewater treatment.
文摘To ensure the safe transportation of radioactive materials,numerous countries have established specific standards.For the transfer of fissile materials,it is imperative that the material within the packaging remains in a subcritical state during routine,normal,and accidental transport conditions.In the event of an accident,the rods within the storage tank may become rearranged,introducing uncertainty that must be accounted for to ensure that criticality analysis results are conservative.Historically,this uncertainty was addressed overly conservatively due to limited research on non-uniform arrangement scenarios,which proved unsuitable for criticality safety analysis of spent fuel packages.This paper introduced three distinct methods to non-uniformly rearrange fuel rods—Uniform Arrangement by Blocks,Layer-by-Layer Determination,and Birdcage Deformation—and meticulously evaluates the influences of rod rearrangement on the effective multiplication factor of neutrons,k eff,utilizing the Monte Carlo method.Ultimately,this study presents a holistic method capable of encompassing the entire spectrum of potential effects stemming from the rearrangement of fuel rods during rods mispositioning accident.By augmenting the safety margin,this approach proves to be adeptly suited for the criticality safety analysis of nuclear fuel transport containers.
基金supported by the Natural Science Foundation of Jiangsu Province(BK20231445)Aeronautical Science Foundation of China(20230028052001).
文摘The proton exchange membrane fuel cell(PEMFC)and the hydrogen hybrid power system are studied by the fuzzy-PID(FPID)controlmethod and the fuzzy-PID controlmethod by Artificial Bee Colony algorithm(ABCFPID),respectively.The results reveal that compared with the FPID control method,the temperature overshoot of the PEMFC stack under the ABC-FPID control method is decreased by 0.6%.Moreover,the circulating water flow rate within the full operating envelope(about 3 min)is reduced by 19.46 L,which means the ABC-FPID control method is more effective in regulating the stack temperature.Then,the ABC-FPID control method is proposed to study the hydrogen hybrid power system,and the system output power matching,operating characteristic curve of the fuel cell,state of charge(SOC)of the lithium battery,system efficiency and hydrogen demand are obtained.The results indicate that the maximum system efficiency reaches 46.3%,the average system efficiency is 33.8%,and the average hydrogen demand is 0.192 kg/s.Overall,the ABC-FPID control method can efficiently ensure the stability of the fuel cell’s output power,and actively prompt the lithium battery to fulfill the function of“peak shaving and valley filling”under variable load power conditions.
基金financially supported by the National Natural Science Foundation of China(No.22309067)the Open Project Program of the State Key Laboratory of Materials-Oriented Chemical Engineering,China(No.KL21-05)the Marine Equipment and Technology Institute,Jiangsu University of Science and Technology,China(No.XTCX202404)。
文摘This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.
