EFFECTS OF RECEIVER MISALIGNMENT ON THE INTERCEPT FACTOR OF PARABOLIC TROUGH COLLECTORS

2021 ◽  
pp. 1-22
Author(s):  
Muhammad Uzair ◽  
Naveed Rehman ◽  
Muhammad Asif
Keyword(s):  
Concentration Ratio ◽  
Latin Hypercube Sampling ◽  
Design Parameters ◽  
Optical Performance ◽  
Parabolic Trough ◽  
Online Tool ◽  
Contour Plots ◽  
Aperture Width ◽  
Parametric Analyses ◽  
Tracing Method

Abstract This study developed a methodology for determining the intercept factor (γ) and reports the effects of varying the design parameters, within realistic ranges, on the optical performance of parabolic trough collectors (PTC). The design equations account for the aperture width of the concentrator, the geometric concentration ratio, rim-angle and misalignment of the receiver, characterized by the radial and angular offsets. The Latin Hypercube Sampling (LHS) based ray-tracing method was used. Validation of the method was performed by comparing the results obtained by tracing a single ray with measurements obtained in a 2D drafting program. Then, parametric analyses were performed to determine the effects of changing the radial and angular offset, geometric concentration ratio and rim-angle on the percentage change in intercept factor (γΔ) with respect to the γ of a PTC with a perfectly aligned receiver. Finally, contour plots depicting the γ of various standard troughs over the range of radial and angular offsets were plotted, compared and discussed. An online tool is also presented to help designers and researchers analyze these effects quickly by providing the design parameters.

Intercept Factor for a Beam-Down Parabolic Trough Collector

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Muhammad Uzair ◽  
Naveed ur Rehman
Keyword(s):  
Ray Tracing ◽  
Concentration Ratio ◽  
Design Parameters ◽  
Two Dimensional ◽  
Parabolic Trough ◽  
High Concentration ◽  
Angular Misalignment ◽  
Online Tool ◽  
Parabolic Trough Collector

Abstract This paper presents a method for evaluating the intercept factor (γ) of a beam-down parabolic trough collector (BDPTC), accounting for collector design, solar cone, and shading on the aperture due to secondary reflectors. A numerical ray-tracing technique was developed and used for the purpose. Validation was performed by comparing the results with rays traced in a two-dimensional drafting program. The effects of changing the rim-angle and angular misalignment associated with the primary and secondary concentrators for various designs are presented and discussed in detail. The optimum values of the design parameters for low, medium, and high concentration ratio BDPTCs are reported. An online tool for quickly estimating γ is also launched in this paper.

scholarly journals Optical Design of a Solar Dish Concentrator Based on Triangular Membrane Facets

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Hongcai Ma ◽  
Guang Jin ◽  
Xing Zhong ◽  
Kai Xu ◽  
Yanjie Li
Keyword(s):  
Focal Plane ◽  
Concentration Ratio ◽  
Collection Efficiency ◽  
Optical Design ◽  
Design Procedure ◽  
Diameter Ratio ◽  
Mean Square ◽  
Optical Performance ◽  
Space Antenna ◽  
Tracing Method

The design of a solar dish concentrator is proposed based on triangular membrane facets for space power applications. The facet concentrator approximates a parabolic surface supported by a deployable perimeter truss structure, which originates from a large aperture space antenna. For optimizing the number of facets rows and focal-diameter ratio of the concentrator, Monte Carlo ray-tracing method is utilized to determine optical performance of the concentrator, and the system root-mean-square (RMS) deviation is considered in this design procedure. A 600-facet concentrator with focal-diameter ratio of 1.1 will achieve 83.63% of radiative collection efficiency over a 15 cm radius disk located in the focal plane, with a mean solar concentration ratio exceeding 300. The study in this paper is helpful for the development of the membrane facet concentrator.

scholarly journals Comparison of Factorial and Latin Hypercube Sampling Designs for Meta-Models of Building Heating and Cooling Loads

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 512
Author(s):  
Younhee Choi ◽  
Doosam Song ◽  
Sungmin Yoon ◽  
Junemo Koo
Keyword(s):  
Latin Hypercube Sampling ◽  
Building Design ◽  
Gain Coefficient ◽  
Design Parameters ◽  
Latin Hypercube ◽  
Heating And Cooling ◽  
Factor Design ◽  
Heating Loads ◽  
Cooling Loads ◽  
Interest In Research

Interest in research analyzing and predicting energy loads and consumption in the early stages of building design using meta-models has constantly increased in recent years. Generally, it requires many simulated or measured results to build meta-models, which significantly affects their accuracy. In this study, Latin Hypercube Sampling (LHS) is proposed as an alternative to Fractional Factor Design (FFD), since it can improve the accuracy while including the nonlinear effect of design parameters with a smaller size of data. Building energy loads of an office floor with ten design parameters were selected as the meta-models’ objectives, and were developed using the two sampling methods. The accuracy of predicting the heating/cooling loads of the meta-models for alternative floor designs was compared. For the considered ranges of design parameters, window insulation (WDI) and Solar Heat Gain Coefficient (SHGC) were found to have nonlinear characteristics on cooling and heating loads. LHS showed better prediction accuracy compared to FFD, since LHS considers the nonlinear impacts for a given number of treatments. It is always a good idea to use LHS over FFD for a given number of treatments, since the existence of nonlinearity in the relation is not pre-existing information.

scholarly journals A New Approach for Design Optimization and Parametric Analysis of Symmetric Compound Parabolic Concentrator for Photovoltaic Applications

2021 ◽  
Vol 13 (9) ◽  
pp. 4606
Author(s):  
Faisal Masood ◽  
Perumal Nallagownden ◽  
Irraivan Elamvazuthi ◽  
Javed Akhter ◽  
Mohammad Azad Alam
Keyword(s):  
Parametric Analysis ◽  
Concentration Ratio ◽  
Synergistic Effects ◽  
Geometric Optimization ◽  
Design Parameters ◽  
Imaging Device ◽  
Compound Parabolic Concentrator ◽  
Photovoltaic Applications ◽  
Half Angle ◽  
The Impact

A compound parabolic concentrator (CPC) is a non-imaging device generally used in PV, thermal, or PV/thermal hybrid systems for the concentration of solar radiation on the target surface. This paper presents the geometric design, statistical modeling, parametric analysis, and geometric optimization of a two-dimensional low concentration symmetric compound parabolic concentrator for potential use in building-integrated and rooftop photovoltaic applications. The CPC was initially designed for a concentration ratio of “2×” and an acceptance half-angle of 30°. A MATLAB code was developed in house to provoke the CPC reflector’s profile. The height, aperture width, and concentration ratios were computed for different acceptance half-angles and receiver widths. The interdependence of optical concentration ratio and acceptance half-angle was demonstrated for a wide span of acceptance half-angles. The impact of the truncation ratio on the geometric parameters was investigated to identify the optimum truncation position. The profile of truncated CPC for different truncation positions was compared with full CPC. A detailed statistical analysis was performed to analyze the synergistic effects of independent design parameters on the responses using the response surface modeling approach. A set of optimized design parameters was obtained by establishing specified optimization criteria. A 50% truncated CPC with an acceptance half-angle of 21.58° and receiver width of 193.98 mm resulted in optimum geometric dimensions.

scholarly journals Analysis of Composite Structures in Curing Process for Shape Deformations and Shear Stress: Basis for Advanced Optimization

2021 ◽  
Vol 5 (2) ◽  
pp. 63
Author(s):  
Niraj Kumbhare ◽  
Reza Moheimani ◽  
Hamid Dalir
Keyword(s):  
Composite Structures ◽  
Latin Hypercube Sampling ◽  
Vital Role ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Curing Process ◽  
Input Variables ◽  
Transient Thermal ◽  
Prototype Design ◽  
Shape Deformations

Identifying residual stresses and the distortions in composite structures during the curing process plays a vital role in coming up with necessary compensations in the dimensions of mold or prototypes and having precise and optimized parts for the manufacturing and assembly of composite structures. This paper presents an investigation into process-induced shape deformations in composite parts and structures, as well as a comparison of the analysis results to finalize design parameters with a minimum of deformation. A Latin hypercube sampling (LHS) method was used to generate the required random points of the input variables. These variables were then executed with the Ansys Composite Cure Simulation (ACCS) tool, which is an advanced tool used to find stress and distortion values using a three-step analysis, including Ansys Composite PrepPost, transient thermal analysis, and static structural analysis. The deformation results were further utilized to find an optimum design to manufacture a complex composite structure with the compensated dimensions. The simulation results of the ACCS tool are expected to be used by common optimization techniques to finalize a prototype design so that it can reduce common manufacturing errors like warpage, spring-in, and distortion.

Design of a compact UWB antenna with a partial ground plane on epoxy woven glass material

2017 ◽  
Vol 24 (1) ◽  
pp. 73-79
Author(s):  
Md. Moinul Islam ◽  
Mohammad Tariqul Islam ◽  
Mohammad Rashed Iqbal Faruque ◽  
Rabah W. Aldhaheri ◽  
Md. Samsuzzaman
Keyword(s):  
Dielectric Material ◽  
Ground Plane ◽  
Ultra Wideband ◽  
Design Parameters ◽  
Uwb Antenna ◽  
Glass Material ◽  
Measurement Results ◽  
Good Term ◽  
Parametric Analyses ◽  
Uwb Applications

AbstractA compact ultra-wideband (UWB) antenna is presented in this paper with a partial ground plane on epoxy woven glass material. The study is discussed to comprehend the effects of various design parameters with explicit parametric analyses. The overall antenna dimension is 0.22×0.26×0.016 λ. A prototype is made on epoxide woven glass fabric dielectric material of 1.6 mm thickness. The measured results point out that the reported antenna belongs to a wide bandwidth comprehending from 3 GHz to more than 11 GHz with VSWR<2. It has a peak gain of 5.52 dBi, where 3.98 dBi is the average gain. Nearly omnidirectional radiation patterns are observed within the operating frequency bands. A good term exists between simulation and measurement results, which lead the reported antenna to be an appropriate candidate for UWB applications.

Numerical Investigation of Natural Convection in a Mono-Span Greenhouse

2012 ◽  
Author(s):  
Sunita Kruger ◽  
Leon Pretorius
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Convection ◽  
Pitch Angle ◽  
Design Tool ◽  
Design Parameters ◽  
Two Dimensional ◽  
Cfd Model ◽  
Indoor Climate ◽  
Contour Plots

In this paper, the use of computational fluid dynamics is evaluated as a design tool to investigate the indoor climate of a confined greenhouse. The finite volume method using polyhedral cells is used to solve the governing mass, momentum and energy equations. Natural convection in a cavity corresponding to a mono-span venlo-type greenhouse is numerically investigated using Computational Fluid Dynamics. The CFD model is designed so as to simulate the climate above a plant canopy in an actual multi-span greenhouse heated by solar radiation. The aim of this paper is to investigate the influence of various design parameters such as pitch angle and roof asymmetry and on the velocity and temperature patterns inside a confined single span greenhouse heated from below. In the study reported in this paper a two-dimensional CFD model was generated for the mono-span venlo-type greenhouse, and a mesh sensitivity analysis was conducted to determine the mesh independence of the solution. Similar two-dimensional flow patterns were observed in the obtained CFD results as the experimental results reported by Lamrani et al [2]. The CFD model was then modified and used to explore the effect of roof pitch angle and roof asymmetry at floor level on the development of the flow and temperature patterns inside the cavity for various Rayleigh numbers. Results are presented in the form of vector and contour plots. It was found that considerable temperature and velocity gradients were observed in the centre of the greenhouse for each case in the first 40mm above the ground, as well as in the last 24mm close to the roof. Results also indicated that the Rayleigh number did not have a significant impact on the flow and temperature patterns inside the greenhouse, although roof angle and asymmetry did. The current results demonstrate the importance of CFD as a design tool in the case of greenhouse design.

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