Parametric Analysis of the Fixed Mirror Solar Concentrator for Medium Temperature Applications

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Ramon Pujol-Nadal ◽  
Víctor Martínez-Moll ◽  
Andreu Moià-Pol
Keyword(s):  
Ray Tracing ◽  
Focal Length ◽  
Design Parameters ◽  
Solar Concentrator ◽  
Medium Temperature ◽  
Thermal Output ◽  
Optimal Values ◽  
Palma De Mallorca ◽  
Trans Asme ◽  
Optical Ray Tracing

The fixed mirror solar concentrator (FMSC) possesses a geometry that can produce thermal energy in medium temperature range. Due to its static reflector, the FMSC has several advantages when compared to other designs, such as being one of the best adapted for integration onto building roofs. An optical ray-tracing analysis of its geometry was presented in a previous paper (Pujol Nadal and Martínez Moll, 2012, “Optical Analysis of the Fixed Mirror Solar Concentrator by Forward Ray-Tracing Procedure,” Trans ASME J. Solar Energy Eng., 134(3), pp. 031009-1-14). The optical results were obtained in function of three design parameters: the number of mirrors N, the ratio of focal length and reflector width F/W, and the intercept factor γ (in order to represent different receiver widths). In this communication, the integrated thermal output of the same parameter combinations has been determined in order to find optimal values of the design parameters at a working temperature of 200 °C. The results were obtained for three different climates and two orientations (North-South and East-West). The results show that FMSC can produce heat at 200 °C with an annual thermal efficiency of 39, 44, and 48%, dependent of the location considered (Munich, Palma de Mallorca, and Cairo). The best FMSC geometries in function of the design parameters are exhibited for medium range applications.

scholarly journals Optical modeling of a solar dish thermal concentrator based on square flat facets

2014 ◽  
Vol 18 (3) ◽  
pp. 989-998 ◽  
Author(s):  
Sasa Pavlovic ◽  
Velimir Stefanovic ◽  
Suad Suljkovic
Keyword(s):  
Ray Tracing ◽  
Focal Length ◽  
Performance Model ◽  
Thermal Processes ◽  
Medium Temperature ◽  
Optical Modeling ◽  
Radiative Power ◽  
Temperature Levels ◽  
Reflecting Surface ◽  
Optical Ray Tracing

Solar energy may be practically utilized directly through transformation into heat, electrical or chemical energy. We present a procedure to design a square facet concentrator for laboratory-scale research on medium-temperature thermal processes. The efficient conversion of solar radiation into heat at these temperature levels requires the use of concentrating solar collectors. Large concentrating dishes generally have a reflecting surface made up of a number of individual mirror panels (facets). Optical ray tracing is used to generate a system performance model. A square facet parabolic solar concentrator with realistic specularly surface and facet positioning accuracy will deliver up to 13.604 kW of radiative power over a 250 mm radius disk (receiver diameter) located in the focal plane on the focal length of 1500mmwith average concentrating ratio exceeding 1200. The Monte Carlo ray tracing method is used for analysis of the optical performance of the concentrator and to identify the set of geometric concentrator parameters that allow for flux characteristics suitable for medium and high-temperature applications.

scholarly journals Monte Carlo Ray-Tracing Simulation of a Cassegrain Solar Concentrator Module for CPV

2021 ◽  
Vol 9 ◽  
Author(s):  
Seung Jin Oh ◽  
Hyungchan Kim ◽  
Youngsun Hong
Keyword(s):  
Monte Carlo ◽  
Ray Tracing ◽  
Concentration Ratio ◽  
Collection Efficiency ◽  
Focal Length ◽  
Tracking Error ◽  
Target Area ◽  
Solar Concentrator ◽  
Acceptance Angle ◽  
Energy Applications

The concentration ratio is one of the most important characteristics in designing a Cassegrain solar concentrator since it directly affects the performance of high-density solar energy applications such as concentrated photovoltaics (CPVs). In this study, solar concentrator modules that have different configurations were proposed and their performances were compared by means of a Monte Carlo ray-tracing algorithm to identify the optimal configurations. The first solar concentrator design includes a primary parabolic concentrator, a parabolic secondary reflector, and a homogenizer. The second design, on the other hand, includes a parabolic primary concentrator, a secondary hyperbolic concentrator, and a homogenizer. Two different reflectance were applied to find the ideal concentration ratio and the actual concentration ratio. In addition, uniform rays and solar rays also were compared to estimate their efficiency. Results revealed that both modules show identical concentration ratios of 610 when the tracking error is not considered. However, the concentration ratio of the first design rapidly drops when the sun tracking error overshoots even 0.1°, whereas the concentration ratio of the second design remained constant within the range of the 0.8° tracking error. It was concluded that a paraboloidal reflector is not appropriate for the second mirror in a Cassegrain concentrator due to its low acceptance angle. The maximum collection efficiency was achieved when the f-number is smaller and the rim angle is bigger and when the secondary reflector is in a hyperboloid shape. The target area has to be rather bigger with a shorter focal length for the secondary reflector to obtain a wider acceptance angle.

scholarly journals Ray Tracing Study of Optical Characteristics of the Solar Image in the Receiver for a Thermal Solar Parabolic Dish Collector

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Saša R. Pavlovic ◽  
Velimir P. Stefanovic
Keyword(s):  
Ray Tracing ◽  
Low Cost ◽  
Optical Design ◽  
Solar Concentrator ◽  
Solar Collectors ◽  
Focal Distance ◽  
Medium Temperature ◽  
Parabolic Dish ◽  
Parabolic Dish Concentrator ◽  
Temperature Levels

This study presents the geometric aspects of the focal image for a solar parabolic concentrator (SPC) using the ray tracing technique to establish parameters that allow the designation of the most suitable geometry for coupling the SPC to absorber-receiver. The efficient conversion of solar radiation into heat at these temperature levels requires a use of concentrating solar collectors. In this paper detailed optical design of the solar parabolic dish concentrator is presented. The system has diameter D=3800 mm and focal distance f=2260 mm. The parabolic dish of the solar system consists of 11 curvilinear trapezoidal reflective petals. For the construction of the solar collectors, mild steel-sheet and square pipe were used as the shell support for the reflecting surfaces. This paper presents optical simulations of the parabolic solar concentrator unit using the ray tracing software TracePro. The total flux on the receiver and the distribution of irradiance for absorbing flux on center and periphery receiver are given. The goal of this paper is to present the optical design of a low-tech solar concentrator that can be used as a potentially low cost tool for laboratory scale research on the medium-temperature thermal processes, cooling, industrial processes, polygeneration systems, and so forth.

A New Design of a (3D) Fresnel Collector With Fixed Mirrors and Tracking Absorber

2000 ◽  
Vol 122 (2) ◽  
pp. 63-68 ◽  
Author(s):  
A. B. Larbi
Keyword(s):  
Concentration Ratio ◽  
Focal Length ◽  
Computer Code ◽  
Design Parameters ◽  
Medium Temperature ◽  
Maintenance Costs ◽  
Energy Delivery ◽  
Half Angle ◽  
Optical Behavior ◽  
Fixed Mirrors

In this paper we developed model of a (3D) Fresnel collector with fixed mirrors and tracking absorber which approximates the optical behavior of a fixed spherical collector (hemispherical bowl). The aim of the study is to investigate the possibility of using this type of installation for applications in medium temperature processes (200—300°C). Via a computer simulation which includes ray-tracing, we evaluate the sensitivity of the geometric concentration ratio to: concentrator design parameters and the option of using curved versus flat elementary mirrors. The developed computer code permits the optimization of the concentrator reflecting area, the focal length (or rim half-angle), and the dimensions and number of reflecting elementary mirrors. The (3D) Fresnel collectors can be a practical alternative to spherical collectors (hemispherical bowl). Capital and maintenance costs can be significantly lower than for spherical collectors, but with reduced energy delivery. [S0199-6231(00)00302-6]

RAY-TRACING ANALYSIS OF A TWO-STAGE SOLAR CONCENTRATOR

2010 ◽  
Vol 34 (2) ◽  
pp. 263-275 ◽  
Author(s):  
Dominic Groulx ◽  
Benjamin Sponagle
Keyword(s):  
Solar Energy ◽  
Ray Tracing ◽  
Energy Flux ◽  
Incident Energy ◽  
Focal Length ◽  
Target Position ◽  
The Sun ◽  
Solar Concentrator ◽  
Secondary Mirror ◽  
Solar Energy Flux

A ray-tracing analysis was conducted on a 2-stage solar concentrator made of two parabolic mirrors created by Lunenburg Industrial Foundry & Engineering (LIFE). The effects of the secondary mirror’s focal length, the distance between the secondary mirror and the target, and the misalignment with the sun were studied. The focal length of the secondary mirror determines the maximum local solar energy flux Φ that can be achieve on the target. For the optimal focal length of 157.9ʺ, a maximum Φ = 1.2 x 104 MW/m2 was achieve compare to Φ = 1680 MW/m2 for the initial LIFE’s focal length of 158.8125ʺ. The concentrator concentrates all the incident energy from the sun on the target, and that independently of the secondary mirror’s focal length (within the range studied), as long as the target position is within an 11 cm zone. Small misalignments in the order of ±0.2° would bring the concentration efficiency to zero.

A Hybrid Ray-Tracing Optical Model for Compound Parabolic Concentrators

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
Donghao Xu ◽  
Ming Qu ◽  
Zhiyao Yang
Keyword(s):  
Optical Properties ◽  
Ray Tracing ◽  
Optical Model ◽  
Film Theory ◽  
Diffuse Radiation ◽  
Design Parameters ◽  
Optical Simulation ◽  
Medium Temperature ◽  
Angular Dependency ◽  
Glass Envelope

Abstract Compound parabolic concentrator (CPC), as a hybrid of the stationary and the tracking collectors, can collect both direct beam and diffuse radiation. CPCs are favorable choices for medium-temperature applications for their high thermal efficiency and their cost-effectiveness. Optical models are important tools to predict the solar concentrating capability of the CPC. Despite the numerous, optical models developed in the literature and used for parametric studies of the optical characteristics of CPCs, the angular optical properties of the glass envelope, reflector, and receiver are rarely included. Moreover, most existing optical modeling studies of CPCs did not consider or present the loss associated with the refraction in the glass envelope. This study aims to fill these gaps by developing a comprehensive CPC optical model with the capability of profile generation, hybrid ray-tracing (HRT), surface property simulation, and sky model. The HRT can achieve high accuracy using significantly fewer computation resources compared with Monte Carlo ray-tracing (MCRT) and was validated against tracepro. The new optical model incorporates angular and spectrum dependence of optical properties for refraction and reflection using multilayer thin-film theory. Finally, the proposed HRT model was used to analyze the error associated with neglecting geometric design parameters and angular dependency of optical properties in optical simulation. The results suggest that the gaps between the receiver, glass envelope, and the reflector, the refraction of the glass and angular dependence of transmittance, and absorptance should be included in simulation to avoid considerable errors.

Optical Analysis of the Fixed Mirror Solar Concentrator by Forward Ray-Tracing Procedure

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Ramon Pujol Nadal ◽  
Víctor Martínez Moll
Keyword(s):  
Ray Tracing ◽  
Power Plants ◽  
Thermal Power ◽  
Production Costs ◽  
Electricity Production ◽  
Design Parameters ◽  
Solar Concentrator ◽  
Optical Efficiency ◽  
3D Ray Tracing ◽  
Positive Effect

The fixed mirror solar concentrator (FMSC) is a mobile focus concentrator whose design emerged in the 1970s in an effort to reduce electricity production costs in solar thermal power plants. This geometry has not yet been analyzed with 3D ray-tracing procedures. The geometry of FMSC is defined using three parameters: the number of mirrors N, the ratio of focal length and reflector width F/W, and the intercept factor γ (in order to represent different receiver widths). For the analysis, a 3D ray-tracing code that allows the characterization of solar concentrators was developed. A standard evacuated tube was used as a receiver. The geometric concentration ratio, the optical efficiency, and the transversal and longitudinal incidence angle modifier (IAM) curves for different values of design parameters were calculated. High concentrations imply low F/W values and for high efficiencies, large intercept factor values are required. Increasing the F/W ratio has a positive effect on the transversal IAM, yet a negative one for the longitudinal IAM. Increasing the number of mirrors has a negative effect on both IAM curves due to the self-shadowing between the adjacent steps. Increasing the intercept factor only has a significant positive effect on the longitudinal IAM. The goodness of the IAM factorization approach was analyzed, and it was found that it can be used as long as a new correction factor to account for the focus displacement is introduced. The results presented in this paper provide information, in form of curves, regarding the optical behavior of the FMSC in terms of different design parameters in order to know the possibility to use the FMSC in medium range temperature applications.

Justification of design parameters of the fractional reaping conveyor and its devices for removal of beveled stems from under the wheels of the vehicle

2019 ◽  
Vol 1 (3) ◽  
pp. 1-10
Author(s):  
Mikhail M. Konstantinov ◽  
Ivan N. Glushkov ◽  
Sergey S. Pashinin ◽  
Igor I. Ognev ◽  
Tatyana V. Bedych
Keyword(s):  
Optimal Design ◽  
Technological Process ◽  
Design Parameters ◽  
Theoretical Studies ◽  
Optimal Parameters ◽  
Belt Conveyor ◽  
Grain Crops ◽  
Mode Of Operation ◽  
Optimal Values ◽  
Main Component

In this paper we consider the structural and technological process of the combine used in the process of separate harvesting of grain crops, as well as a number of its parameters. Among the main units of the combine, we allocate a conveyor and devices for removing beveled stems from under the wheels of the vehicle. The principle of operation of the conveyor at different phases of the Reaper and especially the removal of cut stems from under the wheels of the vehicle during operation of the Reaper. The results of theoretical studies on the establishment of the optimal design of the parameters of the belt conveyor are presented, the ranges of their optimal values are considered and determined. Studies on the establishment of optimal parameters of the screw divider in the Reaper, which is the main component of the device for removal of beveled stems, are presented. Taking into account the optimal design and mode of operation of the screw divider, the correct work is provided to remove the cut stems from under the wheels of the harvester.

scholarly journals Investigating Intense Rainfall Influence on Distance Measurement with a Time-of-Flight Camera Sensor Using Optical Ray-Tracing Simulation Technique

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1056
Author(s):  
Marcus Baumgart ◽  
Norbert Druml ◽  
Markus Dielacher ◽  
Cristina Consani
Keyword(s):  
Ray Tracing ◽  
Time Of Flight ◽  
Autonomous Driving ◽  
Intense Rainfall ◽  
Signal Suppression ◽  
Tof Camera ◽  
Ray Tracing Simulation ◽  
Camera Sensors ◽  
Optical Ray Tracing ◽  
Rain Effect

Robust, fast and reliable examination of the surroundings is essential for further advancements in autonomous driving and robotics. Time-of-Flight (ToF) camera sensors are a key technology to measure surrounding objects and their distances on a pixel basis in real-time. Environmental effects, like rain in front of the sensor, can influence the distance accuracy of the sensor. Here we use an optical ray-tracing based procedure to examine the rain effect on the ToF image. Simulation results are presented for experimental rain droplet distributions, characteristic of intense rainfall at rates of 25 mm/h and 100 mm/h. The ray-tracing based simulation data and results serve as an input for developing and testing rain signal suppression strategies.

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