Conventional concentrator photovoltaics(CPV)face a persistent trade-off between high efficiency and high cost,driven by expensive multi-junction solar cells and complex active cooling systems.This study presents a com...Conventional concentrator photovoltaics(CPV)face a persistent trade-off between high efficiency and high cost,driven by expensive multi-junction solar cells and complex active cooling systems.This study presents a computational investigation of a novel Multi-Focal Pyramidal Array(MFPA)-based CPV system designed to overcome this limitation.The MFPA architecture employs a geometrically optimized pyramidal concentrator to distribute concen-trated sunlight onto strategically placed,low-cost monocrystalline silicon cells,enabling high efficiency energy capture while passively managing thermal loads.Coupled optical thermal electrical simulations in COMSOL Multiphysics demonstrate a geometric concentration ratio of 120×,with system temperatures maintained below 110℃ under standard 1000 W/m2 Direct Normal Irradiance(DNI).Ray tracing confirms 95%optical efficiency and a concentrated light spot radius of 2.48 mm.Compared with conventional CPV designs,the MFPA improves power-per-cost by 25%and reduces tracking requirements by 50%owing to its wide±15°acceptance angle.These results highlight the MFPA’s potential as a scalable,low-cost,and energy-efficient pathway for expanding solar power generation.展开更多
Laser hot wire cladding,with the prominent features of low heat input,high energy efficiency,and high precision,is widely used for remanufacturing metal parts.The cladding process,however,needs to be improved by using...Laser hot wire cladding,with the prominent features of low heat input,high energy efficiency,and high precision,is widely used for remanufacturing metal parts.The cladding process,however,needs to be improved by using a quantitative method.In this work,volumetric defect ratio was proposed as the criterion to describe the integrity of forming quality for cladding layers.Laser deposition experiments with FV520B,one of martensitic stainless steels,were designed by using the Taguchi method.Four process variables,namely,laser power(P),scanning speed(Vs),wire feed rate(Vf),and wire current(/),were optimized based on the analysis of signal-to-noise(S/N)ratio.Metallurgic observation of cladding layer was conducted to compare the forming quality and to validate the analysis method.A stable and continuous process with the optimum parameter combination produced uniform microstructure with minimal defects and cracks,which resulted in a good metallurgical bonding interface.展开更多
文摘Conventional concentrator photovoltaics(CPV)face a persistent trade-off between high efficiency and high cost,driven by expensive multi-junction solar cells and complex active cooling systems.This study presents a computational investigation of a novel Multi-Focal Pyramidal Array(MFPA)-based CPV system designed to overcome this limitation.The MFPA architecture employs a geometrically optimized pyramidal concentrator to distribute concen-trated sunlight onto strategically placed,low-cost monocrystalline silicon cells,enabling high efficiency energy capture while passively managing thermal loads.Coupled optical thermal electrical simulations in COMSOL Multiphysics demonstrate a geometric concentration ratio of 120×,with system temperatures maintained below 110℃ under standard 1000 W/m2 Direct Normal Irradiance(DNI).Ray tracing confirms 95%optical efficiency and a concentrated light spot radius of 2.48 mm.Compared with conventional CPV designs,the MFPA improves power-per-cost by 25%and reduces tracking requirements by 50%owing to its wide±15°acceptance angle.These results highlight the MFPA’s potential as a scalable,low-cost,and energy-efficient pathway for expanding solar power generation.
基金This work was financially supported by the National Basic Research Program of China(97 Program)(Grant No.2011CB013404).
文摘Laser hot wire cladding,with the prominent features of low heat input,high energy efficiency,and high precision,is widely used for remanufacturing metal parts.The cladding process,however,needs to be improved by using a quantitative method.In this work,volumetric defect ratio was proposed as the criterion to describe the integrity of forming quality for cladding layers.Laser deposition experiments with FV520B,one of martensitic stainless steels,were designed by using the Taguchi method.Four process variables,namely,laser power(P),scanning speed(Vs),wire feed rate(Vf),and wire current(/),were optimized based on the analysis of signal-to-noise(S/N)ratio.Metallurgic observation of cladding layer was conducted to compare the forming quality and to validate the analysis method.A stable and continuous process with the optimum parameter combination produced uniform microstructure with minimal defects and cracks,which resulted in a good metallurgical bonding interface.
