Solar Compound Parabolic Concentrator Research Articles

Model construction and performance investigation of compound parabolic concentrator based on satellite solar wing photovoltaic arrays

Experimental research has shown that applying solar concentrator to satellite system could significantly improve its comprehensive benefits. Therefore, theoretical, experimental and numerical studies on satellite solar wing coupled with CPC (Compound Parabolic Concentrator, CPC) are carried out in this study. A mathematical model of SSW-CPC (Satellite Solar Wing CPC, SSW-CPC) which is suitable for space Satellite Solar Wing is theoretically constructed, and the concentrating performance of the constructed SSW-CPC is verified by the visual laser experiment. The results show that the concentrating performance of SSW-CPC is consistent with the theoretical results, and the energy flux distribution on the absorber surface has better uniformity. The study of synchronous satellites operation at the equatorial plane also found that the power generation of the SSW-CPC has increased by 24.4 % compared to the conventional satellite solar wing, which can provide more rapid, abundant and stable power resources for the electrical equipment of satellite system. The results of the economic evaluation show that the mass of satellite system is reduced by 5.3 %, which is beneficial to save the launch cost.

Model construction and performance research of the optimized compound parabolic concentrator based on critical truncation and multi-section congruent

Solar CPC (Compound Parabolic Concentrator, CPC) has a limited ability to collect solar radiation at the top of the reflection surface, and the energy flux distribution on the absorber surface is not uniform. The paper presents an optimized model of N-CPC (No-Gap Escape CPC, N-CPC) that is constructed through critical truncation and multi-section congruent, and the model parameters are determined using the principle of non-imaging optical edge rays, and the theoretical reliability and optical performance are verified through laser experiments and simulation analysis. The research results show that compared with N-CPC with an equivalent geometrical concentration ratio, O-CPC (Optimized CPC, O-CPC) effectively enhances the acceptable range of incident rays, with an average optical efficiency of 40.60%, which beam radiation collection is increased by 3.06% and diffuse radiation collection is increased by 38.92%, effectively reducing the peak energy flux distribution. Combined with economic analysis, O-CPC has a broader application prospect.

Construction and concentrating performance of a critically truncated compound parabolic concentrator without light escape

Conventional solar CPC (Compound Parabolic Concentrator, CPC) has a limited collection of solar radiation at the end of the concentrating surface, which is not conducive to its wide application. In the present research, a solar CT-CPC (Critically Truncated CPC, CT-CPC) without light escape is proposed and constructed for the vacuum tube absorber, and discusses its optical properties, which provides a choice for improving or reforming the existing CPC system. Based on the edge ray principle, the geometric model of the CT-CPC is designed by the dichotomy method, and the concentrating performance of the CT-CPC is verified by the adjustable laser experiment. The study found that the average optical efficiency of CT-CPC reaches 47.84% and is 7.2% higher than the traditional S-CPC (Standard CPC, S-CPC) without light escape at the same aperture, and the energy flux distribution on the absorber surface is also more uniform, which is beneficial to improving system efficiency. The effective working hours of CT-CPC is higher than the S-CPC in the whole year, and the average effective working hours is 8.8 h and 5.7 h, respectively. The total annual radiation collection of CT-CPC is 3397 MJ/m2, which is 11.2% higher than the S-CPC. Furthermore, the economic analysis shows that solar CT-CPC has significant advantages and more friendly engineering application potential.

A novel solution method for reflector shape of solar Compound Parabolic Concentrator and verification

In the existing studies, there are many methods to obtain the reflector shape equations of a CPC(Compound Parabolic Concentrator), but these methods are complicated and not unified. This paper aims to propose a novel method that is based on the edge-ray principle, the differential geometry theory, and the geometrical optical reflection law to get the reflector shape equations. Then, the reflector shape equations of an arc absorber CPC (A-CPC) which focuses light on the lower part of a circular absorber are calculated. The optical properties of such an A-CPC experimental model determined by these equations are studied via laser experiments. Afterward, the error between the calculated values obtained by MCRT(Monte Carlo Ray-Trace) method and experimental values are analyzed. The experimental results show that the optical properties of the A-CPC are in accordance with the theoretical expectations. They indicate also that the theoretical method is flexible and suitable for calculating a specific CPC reflector shape.

The influence of gap losses on the optical, energy, and exergy efficiencies of the all-glassed evacuated tube compound parabolic concentrator (CPC) solar collectors

ABSTRACT The compound parabolic concentrators (CPCs) are of importance due to their capability in absorbing the incident solar radiation in a wide limit. The present paper deals with the optical and thermodynamic analysis of a solar CPC applying the accurate solar ray-tracing analysis. To this end, the optical efficiency of the CPC was obtained for different geometric concentration ratios () based on the CPC modified equations and considering the diffuse radiation effects. The results demonstrated that the highest solar radiation absorption is obtained for of 1.63. The outlet temperature (), energy and exergy efficiencies ( and ) of the stationary evacuated tube CPC were compared with those of two different evacuated tube solar collectors without a concentrator (with large or low distance between the tubes). Based on the results, the average incident solar radiation of the CPC collector is higher than that of two other solar collectors without a concentrator. Besides, of the CPC is higher than that of other collectors within the range of effective reflective angle of the CPC, while for the higher incident angles, is lower than or equal to the other two collectors without a concentrator.

Performance Comparison of CPC based solar installations at different locations in India and analysis of variation pattern

Currently the industrial heat demand is met by using expensive fossil fuels. Exclusive use of solar energy is not feasible due to the fluctuating pattern of solar radiation intensity. Solar hybridization with the existing heating system can be an appropriate solution to meet the process heat requirement of many industries. Concentrator Solar Thermal (CST) technologies can generate the medium temperature heat required for industrial processes. The present study was undertaken with an objective of comparing and analyzing the designed performance of the solar fields using the Compound Parabolic Concentrator (CPC) technology against the actual measured performance values for boiler feed water preheating application at two different locations in India. The optical efficiency of the CPC collector, 64.8%, obtained when tested as per part 5 of IS 16648:2017 was used for designing the solar fields as per the daily heat requirement. The performance of the installations at both the locations was monitored for a period of five months. The observed variation in the performance of each installation than the designed performance was compared and analyzed for the causes. The average variation in designed and measured performance was in the range of 9.0% to 9.8% for location 1 and 2 respectively, attributing to heat rejection from the collector attachments and fluid transfer lines, dust effect on the absorber and reflector of CPC, instrument’s uncertainty, other losses due to shadow effect, vacuum loss from the tubes, dislocation of tubes, heat removal and usage pattern etc. The reasons of the losses from both the fields were of the similar nature, which should be taken into account to design a solar thermal system to achieve predicted performance near to the designed performance. Preheating of boiler feed water is one of the potential applications of solar CPC technology.

Design, optimization and comparative study of a solar CPC with a fully illuminated tubular receiver and a fin inverted V-shaped receiver

This work presents the design, optimization, and a comparative study of a compound parabolic concentrator (CPC) using a tube as a receiver with and without a fin inverted V-shaped receiver (finned receiver). The study was mainly based on numerical analysis obtained by using a ray-tracing simulator in CPCs, in order to evaluate the amount of solar irradiation collected on four dates of the year.A north-south orientation was chosen, with and without a solar tracking system, at a fixed tilt angle of 32 and 0° for each case. The results showed that a CPC using a tubular receiver with a solar tracking system and a surface tilt of 32 and 0° reaches solar irradiation levels of27.96 and 25.35 kWh/m2, while a CPC with a finned receiver reaches 26.87 and 24.98 kWh/m2, respectively. In the case of arrangements without a solar tracking system, the values reached were 7.03 and 5.60 kWh/m2for tubular receiver and 16.83 and 12.85 kWh/m2for the finned receiver, respectively. CPC with a tubular receiver proved to be more feasible when using a solar tracking system, in contrast to a CPC with a finned receiver, which had better feasibility in arrangements that do not include solar tracking.

Numerical modeling of heat losses in a line focusing solar compound parabolic concentrator with planar absorber

In this work, a three-dimensional steady state thermal model is developed for a compound parabolic concentrator of 2× concentration considering the effects of surface radiation and wall conduction. The performance of the compound parabolic concentrator is modeled to obtain the convective and radiative heat loss under the influence of different parameters such as absorber temperature, absorber emissivity, ambient temperature, external heat loss coefficient, aspect ratio and concentrator tilt. The turbulent natural convection in the concentrator is modeled using standard two equation k-ε turbulent model with enhanced wall treatment. For the surface radiation inside the concentrator, discrete ordinate radiation model is used. The thermo physical properties of air inside the cavity are assumed to be constant except the density which is modeled as incompressible ideal gas. The conduction at the walls is accounted by setting suitable wall thickness for reflectors, glass cover and end walls in the solver. This work clearly demonstrates the need for a three dimensional numerical simulation and coupled natural convection and radiation to exactly reproduce the velocity fields as would be obtained in experiments. The convective Nusselt number, radiative Nusselt Number and thermal stratification are obtained from the parametric study. This study on estimation of heat losses in compound parabolic concentrator is applicable to both solar thermal and solar photo-voltaic collectors with a view of modifying the concentrator design to optimize its thermal performance.

Low Cost High-Accuracy Compound Parabolic Concentrator System—A Manufacturing Methodology

Abstract One of the problems of designing a solar compound parabolic concentrator (CPC) is related to its manufacturing shape accuracy. The complexity of curving and holding the CPC profile in place is indeed a challenging issue, especially because there are no standardized molds and the process is typically handmade. It is very easy to provoke misalignment on the CPC surface and in consequence, divert the solar incident rays, affecting significantly the optical efficiency of the system. This work presents a novel, inexpensive methodology to manufacture a CPC with accuracy by using basic tools. The design starts with the acquisition of a pair of medium-density fiberboard wooden templates of the CPC profile that are used later to make a Styrofoam CPC mold and then cut with a hot-wire technique. A high-reflectance anodized aluminum sheet is curved to approximate the CPC shape and is then coupled with the temporary Styrofoam mold. The last part consists of the elaboration of a housing system to contain the parts. This is consolidated by a polyurethane resin that expands and fills all enclosure cavities, offering stiffness and stability. A photogrammetry analysis was implemented for the validation of the surface shape accuracy. The results from the optical analysis show that this technique achieved a high degree of accuracy and homogeneity on the CPC surface shape.

Energy and environmental analysis of an indirect hybrid solar dryer of wood using TRNSYS software

The aim of this work is to develop a numerical model for investigating the performance of an indirect hybrid solar dryer of wood using TRNSYS software. A solar compound parabolic concentrator (CPC) is used to produce thermal energy and the hourly dynamic simulations are conducted under Moroccan meteorological data. A comparative study between our numerical results and experimental results shows a good agreement and the Mean Relative Error (MRE) and the Root Mean Squared Error (RMSE) are 3.9% and 0.024 kg/kg, respectively. The energetic performance of the solar dryer components is investigated and the effect of some design and operation parameters on drying kinetic is presented. An environmental analysis is performed by focusing on the amount of carbon dioxide (CO2) emissions due to the combustion at the auxiliary heater system. Results show that the integration of the solar collector into the dryer system leads to reduce the energy consumption by the auxiliary heater system and to avoid annually about 34% of CO2 emissions.

新型圆形吸收体太阳能复合抛物聚光器面形构建及光学分析

新型圆形吸收体太阳能复合抛物聚光器面形构建及光学分析

Preliminary analysis on thermodynamic and thermo‐economic performance of a solar CPC–KCS hybrid system

Using solar collectors to actuate Kalina cycle system (KCS) for electricity generation has been an attractive way to take advantage of solar energy. Most of the existing research is about KCS integrated with flat plate collector, evacuated tube collector, or concentrating collectors; however, little research focuses on the KCS powered by compound parabolic concentrator (CPC). Considering the merits of CPC, a Kalina 11 cycle system which is directly powered by CPC, named as solar CPC–KCS hybrid system is studied as the research object. Energy, exergy and thermo‐economic models are established to estimate the system performance by varying the solar radiation, evaporating temperature and concentration of working fluid. Results show that higher evaporating temperature improves thermal and exergy efficiency. There are optimal values of Te for maximum wnet, that is, Te,opt = 422.15, 434.15, and 446.15 K, respectively, at Xr = 0.95, 0.93, and 0.91; while Te,opt = 443.15, 437.15, and 425.15 K at Xb = 0.8, 0.7, and 0.6. Higher Xr and lower Xb is generally favorable for system performance. But when Te ≥ 422.15 K, lower Xb is not beneficial to ηex improvement anymore. Additionally, once evaporating temperature exceeds 439.15 K, it is cost‐effective to install a superheater to avoid erosion potential risk. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13135, 2019

Uncertain Analysis of a Stationary Solar Compound Parabolic Concentrator PV Collector System Using Fuzzy Set Theory

The uncertain analysis of fixed solar compound parabolic concentrator (CPC) collector system is investigated for use in combination with solar PV cells. Within solar CPC PV collector systems, any radiation within the collector acceptance angle enters through the aperture and finds its way to the absorber surface by multiple internal reflections. It is essential that the design of any solar collector aims to maximize PV performance since this will elicit a higher collection of solar radiation. In order to analyze uncertainty of the solar CPC collector system in the optimization problem formulation, three objectives are outlined. Seasonal demands are considered for maximizing two of these objectives, the annual average incident solar energy and the lowest month incident solar energy during winter; the lowest cost of the CPC collector system is approached as a third objective. This study investigates uncertain analysis of a solar CPC PV collector system using fuzzy set theory. The fuzzy analysis methodology is suitable for ambiguous problems to predict variations. Uncertain parameters are treated as random variables or uncertain inputs to predict performance. The fuzzy membership functions are used for modeling uncertain or imprecise design parameters of a solar PV collector system. Triangular membership functions are used to represent the uncertain parameters as fuzzy quantities. A fuzzy set analysis methodology is used for analyzing the three objective constrained optimization problems.

Solar Ray Tracing Analysis to Determine Energy Availability in a CPC Designed for Use as a Residential Water Heater

Compound parabolic concentrators are relevant systems used in solar thermal technology. With adequate tailoring, they can be used as an efficient and low-cost alternative in residential water heating applications. This work presents a simulation study using a ray tracing analysis. With this technique, we simulate the interaction between solar rays and solar concentrator to quantify the amount of energy that impinges on the receiver at a particular time. Energy availability is evaluated in a comparison of two configurations throughout the year: static setup at 21° and multi-position setup; tilted with respect to the horizontal, depending on three seasonal positions: 0° for summer, 16° for spring/autumn, and 32° for winter, with the aim to evaluate the amount of available energy in each season. The fact that a tracking system can be dispensed with also represents an economical option for the proposed application. The results showed that at 21°, the proposed solar Compound Parabolic Concentrator (CPC) works satisfactorily; however, by carrying out the selected angular adjustments, the overall energy availability increased by 22%, resulting in a more efficient option. The most effective design was also built and analyzed outdoors. The obtained thermal efficiency was of ~43%. The optical design and its evaluation developed herein proved to be a valuable tool for prototype design and performance evaluation.

Influence of a compound parabolic concentrator in the performance of a solar diffusion absorption cooling system

This article presents the performance of a diffusion absorption cooling system that uses a solar compound parabolic concentrator (CPC) as the heat source. The cooling system uses lithium nitrate (LiNO3) and sodium thiocyanate (NaSCN) absorbent substances, and ammonia (NH3) as a refrigerant. The heat transfer fluids between the CPC and the cooling system studied were glycerol–water (C3H8O3–H2O), ethylene glycol–water (C2H6O2–H2O) and propylene glycol–water (C3H8O2–H2O). For the study of the solar cooling system, a mathematical model was developed and a simulator validated with experimental results of a properly designed CPC. The effects of the heat transfer fluid concentration and mass flow rate were evaluated against the coefficient of performance (COP). In addition, the work includes assessing the influence of the solar radiation and the ambient temperature on the solar cooling system COP. According to the results, the best options were the NH3–LiNO3 working mixture and the C3H8O3–H2O heat transfer fluid.

Solar photocatalytic ozonation of a mixture of pharmaceutical compounds in water

Aqueous solutions of mixtures of four pharmaceutical compounds (atenolol, hydrochlorothiazide, ofloxacin and trimethoprim) both in Milli-Q ultrapure water and in a secondary effluent from a municipal wastewater treatment plant have been treated at pH 7 by different oxidation methods, such as conventional ozonation, photolytic ozonation, TiO2 catalytic ozonation, TiO2 photocatalytic oxidation and TiO2 photocatalytic ozonation. Experiments were carried out using a solar compound parabolic concentrator. The performance results have been compared in terms of removal of emerging contaminants (ECs), generation rate of phenolic intermediates, organic matter mineralization, ecotoxicity removal and enhancement of biodegradability. Also, the consumption of ozone to achieve certain treatment goals (95% removal of ECs and 40% mineralization) is discussed. Results reveal that solar photocatalytic ozonation is a promising oxidation method as it led to the best results in terms of EC mineralization (∼85%), toxicity removal (∼90%) and efficient use of ozone (∼2mgO3mgEC−1 to achieve complete EC removal and ∼18mgO3mgTOC−1 to achieve 40% EC mineralization, respectively).

Parametric studies on the transient performance of a high-temperaturesolar distillation system

A basin-type solar still integrated with an inverted absorber asymmetric line-axis solar compound parabolic concentrator (CPC) is presented as a potential option for high-temperature solar distillation. A simple transient analysis of the system was carried out. Explicit expressions were obtained for the water temperature, glass-cover temperature, water-to-glass-cover temperature differential, distillate output and efficiency of the system. Numerical calculations were made for quantitative assessment of the analytical results. Effects of several parameters, e.g., amount of water, absorptivity and the concentration ratio were studied in detail for the performance of the system. Owing to the heating of basin water from both top and bottom, water temperature rose significantly, accomplishing distillation of the brackish water at high temperature.