Optical Parameters in High-Efficiency Optical Receivers With a Parabolic Reflector Before and After Coating With Ag Film

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Chung Jui Lee ◽  
Jen Fin Lin
Keyword(s):  
High Efficiency ◽  
Film Coating ◽  
Fresnel Lens ◽  
Optical Parameters ◽  
Optical Receivers ◽  
Profile Error ◽  
Optical Efficiency ◽  
Aspheric Lens ◽  
Before And After ◽  
Ag Film

High-efficiency optical receivers before and after the coating of Ag film are composed of a parabolic reflector, a solid parabolic second optical element (SOE), and a Fresnel/aspheric concentrating lens. The optical receivers before the Ag-film coating are fabricated on a high-precision machine tool based on an optimum design attained from ray tracing software simulations. The real profiles of the reflector before and after coating the Ag film are found to be the average of the two orthogonal parabolic profiles. They are then compared to the perfect profile (without profile error and surface roughness) in order to investigate the influence of the profile error and the Ag film on optical performances. The optical parameters, including the total flux, the optical efficiency, and the maximum, minimum, and mean irradiances are evaluated for ray projection simulations in the ASTM G173-03 spectrum. Experiments for the same ray source are also carried out to compare with the simulation results. It is determined that Ag-film coating can improve the profile error and surface roughness of the reflector, thus resulting in all optical parameters being either equal to or higher than those of the reflector without Ag coating. The total flux and optical efficiency obtained from the module with the Fresnel lens has values relatively higher than those of the aspheric lens. The irradiance uniformity for the Fresnel lens is also determined to be better than that of the aspheric lens. The irradiance intensity of the reflector after coating the Ag film has a magnitude at various wavelengths higher than that of the reflector without the Ag-film coating. Due to the coating of the Ag film, the optical receiver shows an almost constant rise in optical efficiency for the two types of concentrating lenses. This characteristic is shown to be valid for both the simulation and experimental results.

scholarly journals Improvement of Optical Performances Using the Hybrid CPV

2020 ◽  
Vol 7 (2) ◽  
pp. 238-245
Author(s):  
Sarah El Himer ◽  
◽  
Ali Ahaitouf ◽  
Keyword(s):  
Solar Cells ◽  
Silicon Solar Cell ◽  
High Efficiency ◽  
Low Cost ◽  
Diffuse Radiation ◽  
Fresnel Lens ◽  
Silicon Solar Cells ◽  
Optical Efficiency ◽  
Direct Radiation ◽  
Simulation Results

Hybrid Concentrated Photovoltaics (HCPVs) are systems in which additional low-cost silicone solar cells are added to take advantage of the power generated by the diffuse radiation lost when using only multi-junction cells that work only with direct radiation. The work has been tested by simulating the performance of a hybrid CPV system composed of a Fresnel lens associated with a pyramid, multi junction cell as well as additional silicon solar cells. This proposal is compared with an ordinary CPV system and a system based on only silicon solar cells. The simulation results show that the CPV makes it possible to have a high optical efficiency of 94% at the pyramid exit for direct radiation, but this high efficiency rapidly decreases to 0% for diffuse radiation. In this case, the silicon solar cell comes into the scene to converts these diffused or non-concentrated rays into electricity, with an optical efficiency of 85%. It was also found that the Hybrid CPV system was able to increase the power by 21% compared to the CPV system.

scholarly journals A Tool to Characterize the Electrical Influence of the Thermal and Mechanical Behaviors of Materials of Optics for CPV applications

MRS Advances ◽  
2017 ◽  
Vol 2 (53) ◽  
pp. 3123-3128
Author(s):  
Arnaud Ritou ◽  
Olivier Raccurt ◽  
Philippe Voarino ◽  
Pierre Besson ◽  
Mathieu Baudrit
Keyword(s):  
Test Bench ◽  
High Efficiency ◽  
Low Cost ◽  
Electrical Performance ◽  
Optical Parameters ◽  
Integration Process ◽  
Mechanical Behaviors ◽  
Cell Temperature ◽  
Optical Efficiency ◽  
Test Conditions

ABSTRACTConcentrating Photovoltaics (CPV) field aims to integrate expensive high efficiency multi-junction cells into modules with low cost concentrating optics. The choice of the optics depends on different factors: easiness of fabrication and integration process, added costs, optical efficiency and the profile of the spot uniformity reaching the cell. Indeed, previous work has shown a dependence between electrical performance and spectral and spatial uniformities of the light on the cell. To analyze it, a solar CPV test bench is developed at CEA-INES facilities. Lens and cell temperature can be applied separately, in order to evaluate independently different test conditions, while electrical or optical parameters are recorded. The present work shows how temperature and mechanical variations on first stage concentrating optic affects module performances. Several optics and materials are compared, in order to present the tool capabilities.

EFFICIENCY OF NEW HEMOSORBENT IN ACUTE AMITRIPTYLINE AND CYCLODOL POISONING

2020 ◽  
pp. 14-18
Author(s):  
A. M. Fomin
Keyword(s):  
Clinical Effect ◽  
High Efficiency ◽  
Initial Level ◽  
Synthetic Polymer ◽  
Complex Treatment ◽  
Direct Hemoperfusion ◽  
Selective Sorption ◽  
Positive Clinical Effect ◽  
Before And After

A complex treatment of a patient with acute amitriptyline and cyclodol poisoning using enterosorption, intestinal lavage and hemosorption on a new column with a synthetic sorbent is presented. A two-layer synthetic polymer column developed for the selective sorption of cytokines by direct hemoperfusion was used for hemosorption. Quantitative determinations of amitriptyline and cyclodol levels before and after the column, as well as before and after hemosorption have showed high efficiency of the sorbent to remove the toxicant from the blood. The use of 6-hour hemosorption allowed to reduce the level of amitriptyline from the initial level by more than 4 times and the level of cyclodol - by more than 3 times to therapeutic levels and to obtain a pronounced positive clinical effect in the complex treatment of a patient with severe poisoning.

scholarly journals Enhancing the Optical Efficiency of Near-Eye Displays with Liquid Crystal Optics

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 107
Author(s):  
Tao Zhan ◽  
En-Lin Hsiang ◽  
Kun Li ◽  
Shin-Tson Wu
Keyword(s):  
Virtual Reality ◽  
Liquid Crystal ◽  
High Efficiency ◽  
Berry Phase ◽  
Optical Element ◽  
Liquid Crystal Polymer ◽  
Proof Of Concept ◽  
Optical Efficiency ◽  
Crystal Polymer ◽  
Light Efficiency

We demonstrate a light efficient virtual reality (VR) near-eye display (NED) design based on a directional display panel and a diffractive deflection film (DDF). The DDF was essentially a high-efficiency Pancharatnam-Berry phase optical element made of liquid crystal polymer. The essence of this design is directing most of the display light into the eyebox. The proposed method is applicable for both catadioptric and dioptric VR lenses. A proof-of-concept experiment was conducted with off-the-shelf optical parts, where the light efficiency was enhanced by more than 2 times.

Design and Evaluation of the Fresnel-Lens Based Solar Concentrator System Through a Statistical-Algorithmic Approach

2018 ◽  
Author(s):  
Hassan Qandil ◽  
Weihuan Zhao
Keyword(s):  
High Temperature ◽  
High Efficiency ◽  
Incident Light ◽  
Thermal Analyses ◽  
Solar Spectrum ◽  
Chromatic Aberration ◽  
Fresnel Lens ◽  
Optimum Number ◽  
Solar Concentrator ◽  
Receiver System

A novel non-imaging Fresnel-lens-based solar concentrator-receiver system has been investigated to achieve high-efficiency photon and heat outputs with minimized effect of chromatic aberrations. Two types of non-imaging Fresnel lenses, a spot-flat lens and a dome-shaped lens, are designed through a statistical algorithm incorporated in MATLAB. The algorithm optimizes the lens design via a statistical ray-tracing methodology of the incident light, considering the chromatic aberration of solar spectrum, the lens-receiver spacing and aperture sizes, and the optimum number of prism grooves. An equal-groove-width of the Poly-methyl-methacrylate (PMMA) prisms is adopted in the model. The main target is to maximize ray intensity on the receiver’s aperture, and therefore, achieve the highest possible heat flux and output concentration temperature. The algorithm outputs prism and system geometries of the Fresnel-lens concentrator. The lenses coupled with solar receivers are simulated by COMSOL Multiphysics. It combines both optical and thermal analyses for the lens and receiver to study the optimum lens structure for high solar flux output. The optimized solar concentrator-receiver system can be applied to various devices which require high temperature inputs, such as concentrated photovoltaics (CPV), high-temperature stirling engine, etc.

scholarly journals Advanced treatment of effluent extended aeration process using biological aerated filter (BAF) with natural media: modification in media, design and backwashing process

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Malakootian ◽  
Ali Toolabi ◽  
Saeed Hosseini
Keyword(s):  
High Efficiency ◽  
Treatment Plant ◽  
Hospital Wastewater ◽  
Optimal Method ◽  
Metal Grid ◽  
Before And After ◽  
The Media ◽  
Aeration Process ◽  
Aerated Filter ◽  
Natural Media

AbstractBiological aerated filters (BAFs) have high filtration efficiency due to their tolerance of hydraulic and organic shocks are suitable for the treatment of complex and sanitary wastewater. In this study, for the first time, natural media of date kernel from Bam city was used as the BAF reactor media, with a meshing sand filter separated by a standard metal grid from the natural filter section used at the end of the reactor. This can be considered an innovation in the media and filtration. Aeration in the related reactor with 160 cm height was performed bilaterally as up-flow and continuously by nozzles throughout the reactor media. In this work, the actual effluent of the hospital wastewater treatment plant was employed as the inflow wastewater to the reactor, and its organic and inorganic parameters were measured before and after the treatment by the BAF reactor. The backwashing process was also studied in three ways: bottom backwashing (TB), top backwashing (BB), and top and bottom backwashing (TBBS), to determine the amount of water consumed and to achieve the desired result. According to the results obtained in this study, the removal efficiencies of inorganic and microbial contaminants, amoxicillin and azithromycin were obtained as follows: BOD5: 98.48%, COD: 92.42%, $${\text{NO}}_{3}^{ - }$$ NO 3 - : 99.4%, P: 93.3%, Coliforms: 97%, Color: 42.8%, Turbidity: 95%, Sulphate: 30%, TSS: 98.9%, Amoxicillin: 20% and azithromycin: 13%. In the backwashing process, the amount of water consumed in these three TB, BB, and TBBS methods were obtained 300, 164, and 118 L, respectively, So, TBBS method was selected as the optimal method. Based on the results obtained in this study, it is concluded that the BAF process with natural date kernel has a high efficiency in removing organic and inorganic contaminants from hospital wastewater, also the concentration of most of the effluent parameters was less or in accordance with EPA standard.

scholarly journals Optical Performance of Single Point-Focus Fresnel Lens Concentrator System for Multiple Multi-Junction Solar Cells—A Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4301
Author(s):  
Yassir A. Alamri ◽  
Saad Mahmoud ◽  
Raya Al-Dadah ◽  
Shivangi Sharma ◽  
J. N. Roy ◽  
...  
Keyword(s):  
Solar Cells ◽  
Numerical Study ◽  
Single Point ◽  
Optical Element ◽  
Fresnel Lens ◽  
Electrical Performance ◽  
High Concentration ◽  
Three Dimensional Model ◽  
Optical Efficiency ◽  
Concave Lens

This paper investigates the potential of a new integrated solar concentrated photovoltaic (CPV) system that uses a solo point focus Fresnel lens for multiple multi-junction solar cells (MJSCs). The proposed system comprises of an FL concentrator as the primary optical element, a multi-leg homogeniser as the secondary optical element (SOE), a plano-concave lens, and four MJSCs. A three-dimensional model of this system was developed using the ray tracing method to predict the influence of aperture width, height, and position with respect to MJSCs of different reflective and refractive SOE on the overall optical efficiency of the system and the irradiance uniformity achieved on the MJSCs’ surfaces. The results show that the refractive homogeniser using N-BK7 glass can achieve higher optical efficiency (79%) compared to the reflective homogeniser (57.5%). In addition, the peak to average ratio of illumination at MJSCs for the reflective homogeniser ranges from 1.07 to 1.14, while for the refractive homogeniser, it ranges from 1.06 to 1.34, causing minimum effects on the electrical performance of the MJSCs. The novelty of this paper is the development of a high concentration CPV system that integrates multiple MJSCs with a uniform distribution of rays, unlike the conventional CPV systems that utilise a single concentrator onto a single MJSC. The optical efficiency of the CPV system was also examined using both the types of homogeniser (reflective and refractive).

Solar Thermophotovoltaic Converters Based on Tungsten Emitters

2006 ◽  
Vol 129 (3) ◽  
pp. 298-303 ◽  
Author(s):  
V. M. Andreev ◽  
A. S. Vlasov ◽  
V. P. Khvostikov ◽  
O. A. Khvostikova ◽  
P. Y. Gazaryan ◽  
...  
Keyword(s):  
Band Gap ◽  
High Efficiency ◽  
Radiation Spectrum ◽  
Cost Effective ◽  
Fresnel Lens ◽  
Photocurrent Density ◽  
Back Side ◽  
High Concentration ◽  
Emitter System ◽  
Solar Powered

Results of a solar thermophotovoltaic (STPV) system study are reported. Modeling of the STPV module performance and the analysis of various parameters influencing the system are presented. The ways for the STPV system efficiency to increase and their magnitude are considered such as: improvement of the emitter radiation selectivity and application of selective filters for better matching the emitter radiation spectrum and cell photoresponse; application of the cells with a back side reflector for recycling the sub-band gap photons; and development of low-band gap tandem TPV cells for better utilization of the radiation spectrum. Sunlight concentrator and STPV modules were designed, fabricated, and tested under indoor and outdoor conditions. A cost-effective sunlight concentrator with Fresnel lens was developed as a primary concentrator and a secondary quartz meniscus lens ensured the high concentration ratio of ∼4000×, which is necessary for achieving the high efficiency of the concentrator–emitter system owing to trap escaping radiation. Several types of STPV modules have been developed and tested under concentrated sunlight. Photocurrent density of 4.5A∕cm2 was registered in a photoreceiver based on 1×1cm2GaSb cells under a solar powered tungsten emitter.

scholarly journals Investigation on extreme frequency shift in silica fiber-based high-power Raman fiber laser

2018 ◽  
Vol 6 ◽  
Author(s):  
Jiaxin Song ◽  
Hanshuo Wu ◽  
Jun Ye ◽  
Hanwei Zhang ◽  
Jiangming Xu ◽  
...  
Keyword(s):  
Frequency Shift ◽  
Fiber Laser ◽  
High Power ◽  
High Efficiency ◽  
Maximum Output Power ◽  
Gain Medium ◽  
Maximum Output ◽  
Optical Efficiency ◽  
Central Wavelength ◽  
Raman Fiber Laser

In this paper, we experimentally investigated the extreme frequency shift in high-power Raman fiber laser (RFL). The RFL was developed by using a pair of fiber Bragg gratings with fixed and matched central wavelength (1120 nm) combined with a piece of 31-m-long polarization maintaining (PM) passive fiber adopted as Raman gain medium. The pump source was a homemade high-power, linearly polarized (LP) wavelength-tunable master oscillator power amplifier (MOPA) source with ${\sim}25~\text{nm}$ tunable working range (1055–1080 nm). High-power and high-efficiency RFL with extreme frequency shift between the pump and Stokes light was explored. It is found that frequency shift located within 10.6 THz and 15.2 THz can ensure efficient Raman lasing, where the conversion efficiency is more than 95% of the maximal value, 71.3%. In addition, a maximum output power of 147.1 W was obtained with an optical efficiency of 71.3%, which is the highest power ever reported in LP RFLs to the best of our knowledge.

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