Optical Performance Comparison of Six ACPCs for Concentrating Radiation on All-Glass Evacuated Solar Tubes

2015 ◽  
Vol 1092-1093 ◽  
pp. 52-58 ◽  
Author(s):  
Rui Hua Xu ◽  
Qi Chao Zhang ◽  
Run Sheng Tang
Keyword(s):  
Ray Tracing ◽  
Concentration Factor ◽  
Performance Comparison ◽  
Optical Performance ◽  
Acceptance Angle ◽  
Direct Sunlight ◽  
Optical Efficiency ◽  
The One ◽  
East West ◽  
Tracing Method

In this work, six asymmetric compound parabolic concentrators (ACPC) were designed for concentrating radiation on all-glass evacuated solar tubes (EST). The ACPCs are required to be horizontally oriented in the east-west direction and to collect direct sunlight for at least 6 hrs in any day of a year. The angular dependence of optical efficiency of six ACPCs, identical in the height of both reflectors after the higher reflector being truncated, was investigated by ray-tracing method, and the annual radiation on EST concentrated by ACPCs was estimated based on solar geometry and monthly horizontally radiation. Results shows that the ACPC designed based on “hat shaped” virtual absorber with a V-groove at the bottom of reflectors is the best in terms of the optical efficiency averaged over the acceptance angle, followed by the one designed based on “hat-shaped” absorber without a V-groove at the bottom, and the one designed based on the cover tube of EST is the worst. However, from the point of annual radiation on EST, the ACPC designed based on the cover tube is the best solution, followed by the one designed based on “ice-cream shaped” absorber and the one designed based on “hat shaped” absorber is the worst due to the smallest geometric concentration factor.

Design of Secondary Optical Element for a Two-Reflector Solar Concentrator

2013 ◽  
Vol 479-480 ◽  
pp. 161-165 ◽  
Author(s):  
Yi Cheng Chen ◽  
Chia Chi You
Keyword(s):  
Ray Tracing ◽  
Optimum Design ◽  
Optical Element ◽  
Solar Concentrator ◽  
Optical Performance ◽  
Parabolic Mirror ◽  
Acceptance Angle ◽  
Optical Efficiency ◽  
Ray Tracing Simulation

This study explores the optimum design of secondary optical element (SOE) for a non-coplanar two-reflector solar concentrator. The non-coplanar solar concentrator comprises a primary parabolic mirror and a secondary hyperbolic mirror. Ray tracing simulation is adopted to investigate the optical performance, including the acceptance angle and the optical efficiency, of the solar concentrator with various designs of SOE. Finally, preliminary optimum designs of SOE are presented and discussed.

Optical Analysis of a Heliostat Array With Linked Tracking

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
M. T. Dunham ◽  
R. Kasetty ◽  
A. Mathur ◽  
W. Lipiński
Keyword(s):  
Concentration Ratio ◽  
Tracking System ◽  
Average Concentration ◽  
Solar Concentrator ◽  
Optical Performance ◽  
Optical Analysis ◽  
Optical Efficiency ◽  
The North ◽  
The Individual ◽  
East West

The optical performance of a novel solar concentrator consisting of a 400 spherical heliostat array and a linked two-axis tracking system is analyzed using the Monte Carlo ray-tracing technique. The optical efficiency and concentration ratio are compared for four different heliostat linkage configurations, including linkages of 1 × 1, 1 × 2, 2 × 2, 4 × 4, and 5 × 5 heliostats for 7-hour operation and the selected months of June and December. The optical performance of the concentrator decreases with the increasing number of heliostats in the individual groups due to increasing optical inaccuracies. In June, the best-performing linked configuration, in which 1 heliostat in the east-west direction and 2 heliostats in the north-south direction are linked, provides a monthly-averaged 7-hour optical efficiency and average concentration ratio of 79% and 511 suns, respectively. In December, the optical efficiency and the average concentration ratio decreases to 61% and 315 suns, respectively.

scholarly journals Environmental, economic and energetic benefits from implantation of several modes of solar collector movements

2021 ◽  
Vol 12 (3) ◽  
pp. 313-321
Author(s):  
Mustafa Hamad ◽  
Mhanna Obaid
Keyword(s):  
Solar System ◽  
Solar Radiation ◽  
Solar Collector ◽  
The Other ◽  
Tracking Systems ◽  
Optical Efficiency ◽  
Solar Radiation Intensity ◽  
Solar Radiation Incident ◽  
The One ◽  
East West

In this research, the performance of a moving solar system on two axes was studied, the east-west axis, this axis represents the tilt angle of the solar collector. The other movement is the surface's rotation around the perpendicular axis on the surface in the east and west directions, which in turn represents the azimuth angle of the solar collector. All possibilities for these movements were also studied, in order to reach the optimal option, which in turn depends on the importance of alication and the available space on the one hand, and the economic conditions on the other hand. The maximum value of solar radiation intensity was adopted as a guide to compare the performance of six options for tracking systems. Despite the high costs of tracking systems, they often have a positive economic return, as these systems increase the efficiency of the solar system, whether it is electric or thermal twice, the first one by increasing the intensity of the solar radiation incident on the solar collector, and the second one by increasing the optical efficiency of the solar collectors and thus increasing the overall efficiency of the device. The percentage of increase in the sixth type of solar energy is about 38% compared to the fixed mode. The minimum optical efficiency of the dual tracking mode has been found as 84%, while for fixed mode is about 48%.

scholarly journals Optimal Design of a Secondary Optical Element for a Noncoplanar Two-Reflector Solar Concentrator

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Yi-Cheng Chen ◽  
Chia-Chi You
Keyword(s):  
Design Process ◽  
Parametric Design ◽  
Optical Element ◽  
Solar Concentrator ◽  
Optical Performance ◽  
Parabolic Mirror ◽  
Acceptance Angle ◽  
Optical Efficiency ◽  
Two Phases ◽  
Ray Tracing Simulation

This paper presents the results of a parametric design process used to achieve an optimal secondary optical element (SOE) in a noncoplanar solar concentrator composed of two reflectors. The noncoplanar solar concentrator comprises a primary parabolic mirror (M1) and a secondary hyperbolic mirror (M2). The optical performance (i.e., acceptance angle, optical efficiency, and irradiance distribution) of concentrators with various SOEs was compared using ray-tracing simulation. The parametric design process for the SOE was divided into two phases, and an optimal SOE was obtained. The sensitivity to assembly errors of the solar concentrator when using the optimal SOE was studied and the findings are discussed.

scholarly journals Performance and Design Optimization of Two-Mirror Composite Concentrating PV Systems

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2875
Author(s):  
Guihua Li ◽  
Yamei Yu ◽  
Runsheng Tang
Keyword(s):  
Tilt Angle ◽  
Three Dimensional ◽  
Acceptance Angle ◽  
Pv System ◽  
Pv Systems ◽  
Calculation Results ◽  
The One ◽  
A Site ◽  
Plate Absorber ◽  
East West

The reflectors of a linear solar concentrator investigated in this work consisted of two plane mirrors (2MCC), and they were designed in such a way that made all radiation within the acceptance angle (θa) arrive on flat-plate absorber, after less than two reflections. To investigate the performance of an east–west aligned 2MCC-based photovoltaic (PV) system (2MCPV), a mathematical procedure was suggested based on the three-dimensional radiation transfer and was validated by the ray-tracing analysis. Analysis indicated that the performance of 2MCPV was dependent on the geometry of 2MCC, the reflectivity of mirrors (ρ), and solar resources in a site, thus, given θa, an optimal geometry of 2MCC for maximizing the annual collectible radiation (ACR) and annual electricity generation (AEG) of 2MCPV in a site could be respectively found through iterative calculations. Calculation results showed that when the ρ was high, the optimal design of 2MCC for maximizing its geometric concentration (Cg) could be utilized for maximizing the ACR and AEG of 2MCPV. As compared to similar compound parabolic concentrator (CPC)-based PV systems, the 2MCPV with the tilt-angle of the aperture yearly fixed (1T-2MCPV), annually generated more electricity when the ρ was high; and the one with the tilt-angle adjusted yearly four times at three tilts (3T-2MCPV), performed better when θa < 25° and ρ > 0.7, even in sites with poor solar resources.

scholarly journals Optical Performance Analysis of Single Flow Through and Concentric Tube Receiver Coupled with a Modified CPC Collector Under Different Configurations

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4147 ◽  
Author(s):  
Akhter ◽  
Gilani ◽  
Al-Kayiem ◽  
Ali
Keyword(s):  
Experimental Testing ◽  
Optical Performance ◽  
Solar Thermal Energy ◽  
Medium Temperature ◽  
Optical Efficiency ◽  
Yearly Average ◽  
Flow Through ◽  
Single Flow ◽  
Evacuated Tube ◽  
East West

Compound parabolic concentrating (CPC) collectors have great potential to provide sustainable solar thermal energy for many applications operating in the medium temperature range. This paper presents the design, development and performance evaluation of a modified CPC collector integrated with an evacuated tube receiver. The optical performance of the designed CPC paired with concentric tube receiver is compared with that of a CPC coupled with single flow through evacuated tube receiver for stationary installation in the East-West and North-South directions. Ray tracing simulations of different configurations demonstrate that CPC coupled with single flow through receivers suffer high gap losses, especially at smaller incidence angles which are considerably alleviated by a concentric tube receiver arrangement. East-West installation of CPC paired with concentric tube receiver exhibited superior optical performance than all other configurations. The yearly average optical efficiency of CPC with concentric tube receiver was 5% higher than that of a single flow through receiver within the acceptance angle. A 60% truncated CPC coupled with concentric tube receiver emerged as the most effective design, which was fabricated for experimental testing. The tests conducted under actual outdoor tropical environmental conditions demonstrated that the experimental optical efficiency reached to about 69% in the case of N-S installation and 66.5% in an E-W arrangement. The experimental results closely match the simulation outcomes, which indicate the proposed performance prediction technique as instrumental for selecting the most effective configuration of CPC collectors for medium temperature heat supply.

Simulation of the internal temperature in the Passol Laboratory, University of Debrecen

2012 ◽  
Vol 3 (1) ◽  
pp. 63-73 ◽  
Author(s):  
I. Csáky ◽  
F. Kalmár
Keyword(s):  
Temperature Variation ◽  
Air Temperature ◽  
Indoor Air ◽  
Storage Capacity ◽  
Building Structures ◽  
Internal Temperature ◽  
The One ◽  
Heavy Structure ◽  
East West ◽  
Made In

Abstract Nowadays the facades of newly built buildings have significant glazed surfaces. The solar gains in these buildings can produce discomfort caused by direct solar radiation on the one hand and by the higher indoor air temperature on the other hand. The amplitude of the indoor air temperature variation depends on the glazed area, orientation of the facade and heat storage capacity of the building. This paper presents the results of a simulation, which were made in the Passol Laboratory of University of Debrecen in order to define the internal temperature variation. The simulation proved that the highest amplitudes of the internal temperature are obtained for East orientation of the facade. The upper acceptable limit of the internal air temperature is exceeded for each analyzed orientation: North, South, East, West. Comparing different building structures, according to the obtained results, in case of the heavy structure more cooling hours are obtained, but the energy consumption for cooling is lower.

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