Nonimaging Solar Energy Concentrators (CPC’s) With Fully Illuminated Flat Receivers: A Viable Alternative to Flat-Plate Collectors

1986 ◽  
Vol 108 (3) ◽  
pp. 252-256 ◽  
Author(s):  
J. M. Gordon
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Closed Form ◽  
Ray Tracing ◽  
Production Costs ◽  
Viable Alternative ◽  
Solar Collectors ◽  
Low Concentration ◽  
Geometric Characteristics ◽  
Energy Delivery

Low-concentration, stationary, nonimaging concentrators (CPC’s) with flat receivers illuminated on both sides are considered as viable alternatives to flat-plate solar collectors. Closed-form, analytic formulae are derived for the geometric characteristics of two concentrator types of greatest interest (i.e., stationary collectors for year-round energy delivery), which enable calculations of collectible energy without computer ray-tracing stimulations. The relative merits of these concentrators in terms of energy collection and production costs are assessed with respect to each other as well as to flat-plate collectors.

Analysis of an Adsorption Chiller Cooling System for Various Types of Solar Collectors Using the F-Chart Cooling Method

2016 ◽  
Author(s):  
I. P. Koronaki ◽  
E. G. Papoutsis ◽  
M. T. Nitsas
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Cooling System ◽  
Energy Performance ◽  
Electrical Network ◽  
Climatic Data ◽  
Solar Collectors ◽  
Adsorption Chiller ◽  
Solar Cooling ◽  
Cooling Method

Solar cooling systems offer a reliable and environmentally friendly alternative to conventional electrically driven vapor compression cooling units. Air conditioning systems powered by solar energy are very attractive because they have zero ozone depletion and global warming potential, their operational cost is low and they do not burden the electrical network during summer months. In this study, the installation of a solar cooling system in various Greek cities is examined. The system utilizes a single-stage, two-bed silica gel-water adsorption chiller driven by heat produced by solar collectors. A lumped parameter model is used to simulate the performance of the adsorption chiller. The optimum tilt of the solar collectors is calculated for each examined city in order for the collected solar energy to be maximized during the summer period (April to September). The climatic data are taken from the technical notes of Greek Regulation for Buildings Energy Performance. Then, using the f-chart cooling method the necessary collectors’ surface area is estimated for every examined city and for different types of flat plate collectors (including advanced flat plate, simple flat plate and hybrid photovoltaic thermal collectors).

Experimental Daily Energy Performance of Flat Plate and Evacuated Tube Solar Collectors

2009 ◽  
Author(s):  
Enrico Zambolin ◽  
Davide Del Col ◽  
Andrea Padovan
Keyword(s):  
Solar Energy ◽  
Flat Plate ◽  
Energy Performance ◽  
Hot Water ◽  
Solar Collectors ◽  
Input Output ◽  
Evacuated Tube Collector ◽  
Daily Energy ◽  
Radiation Test ◽  
Evacuated Tube

New comparative tests on different types of solar collectors are presented in this paper. Tests have been performed at the solar energy conversion laboratory of the University of Padova. Two standard glazed flat plate collectors and one evacuated tube collector are installed in parallel; the evacuated collector is a direct flow through type with external CPC (compound parabolic concentrator) reflectors. The present test rig allows to make measurements on the flat plate, on the evacuated collector or on both simultaneously, by simply acting on the valves to modify the circuit. In this paper measurements of the performance of the evacuated tube collector and flat plate collectors working at the same conditions are reported. Efficiency in stationary conditions is measured following the standard EN 12975-2 [1] and it is compared with the input/output curves measured for an entire day. The main purpose of the present work is to characterize and to compare the daily energy performance of the two types of collectors. An effective mean for describing and analyzing the daily performance is the so called input/output diagram, in which the collected solar energy is plotted against the daily incident solar radiation. Test runs have been performed in several conditions to reproduce different conventional uses (hot water, space heating, solar cooling).

Design and Analysis of Solar Tracking System for Multipurpose Domestic Applications

2013 ◽  
Author(s):  
P. Rhushi Prasad ◽  
P. B. Gangavati ◽  
H. V. Byregowda ◽  
K. S. Badarinarayan
Keyword(s):  
Solar Energy ◽  
Energy Conversion ◽  
Flat Plate ◽  
Tracking System ◽  
Solar Collectors ◽  
Tracking Systems ◽  
Pv Panel ◽  
Energy Conversion Systems ◽  
Flat Plate Collector ◽  
Parabolic Collector

Now-a-days the field of applied mechanical systems opens new horizons for the use of orientation mechanisms. The opportunity to use mechanisms with a “sustainable purpose” leads to new approaches in the development of renewable energy systems design. The evaluation of the existing products shows that the tracking mechanisms for solar energy conversion systems may improve the efficiency of the solar energy conversion systems up to 30% to 50%. Applications of solar energy for domestic and industrial heating purposes have been becoming very popular. However the effectiveness of presently used fixed flat plate collectors, PV panels and parabolic collector are low due to the moving nature of the energy source. The presents research was carried out in the field of increasing the efficiency of the solar energy received by the solar collectors like PV panels, Flat plate collectors, Cylindrical Parabolic collectors using tracking systems by changing the position of the solar collectors correlated to the sun position for getting maximum radiation use of beam radiation falling on the solar collector. Two main aspects are taken into consideration, one optimizing the interaction between the mechatronic system components by integrating the analog electronic system by using a 555 timer in the mechanical model, and secondly by reducing the cost & time for the design process. The research work was carried out for location in chickballapur district at BGS R&D centre in Karnataka State, India. The results obtained in work is 24% increase in tracking efficiency of experimental model of flat plate collector, 30% increase in tracking efficiency in working model flat plate collector, 39 % increase in tracking efficiency of cylindrical parabolic collector and 36% increases in tracking efficiency of the Photovoltaic panel is found when compared to the non-tracking systems respectively. This paper presents the results of PV panel collector in detail for increasing the efficiency of the PV panel collector by tracking system with comparison of non-tracking system.

Optimization of Stationary Flat-Plate Solar Collectors

2015 ◽  
Author(s):  
Singiresu S. Rao
Keyword(s):  
Game Theory ◽  
Solar Energy ◽  
Flat Plate ◽  
Solar Collector ◽  
Probabilistic Approach ◽  
Design Parameters ◽  
Theory Approach ◽  
Solar Collectors ◽  
Beam Radiation ◽  
The Game Theory

The optimum design of stationary flat-plate solar collectors is considered using the game theory approach for multiple objectives. The clear day solar beam radiation and diffuse radiation at the location of the solar collector are estimated. Three objectives are considered in the optimization problem formulation: maximization of the annual average incident solar energy, maximization of the lowest month incident solar energy and minimization of the cost. The game theory solution represents the best compromise in terms of the supercriterion selected. Because some design parameters such as solar constant, altitude, typical day of each month and most of the design variables are not precisely known, a probabilistic approach is also proposed in this work. The results obtained by the determinist and probabilistic approaches are compared. It is found that the absolute value of each objective function decreases with an increase in either the probability of constraint satisfaction or the coefficient of variation of the random variables. This work represents the first work aimed at the application of multi-objective optimization strategy, particularly the game theory approach, for the solution of the solar collector design problem.

Economic Optimization of Stationary Nonevacuated CPC Solar Collectors

1987 ◽  
Vol 109 (1) ◽  
pp. 40-45 ◽  
Author(s):  
M. J. Carvalho ◽  
M. Collares-Pereira ◽  
J. M. Gordon
Keyword(s):  
Low Temperature ◽  
Flat Plate ◽  
Operating Temperature ◽  
Solar Collectors ◽  
Economic Optimization ◽  
Promising Alternative ◽  
Energy Delivery ◽  
Low Concentrations ◽  
East West ◽  
Concentration Ratios

Stationary, nonevacuated CPC solar collectors are a promising alternative to corresponding flat plate collectors in that they offer superior yearly energy delivery at comparable cost for low-temperature thermal applications. For realistic cost scenarios, we determine optimal concentrator configurations and concentration ratios, and calculate their sensitivity to variations in relative component costs, climate, orientation and collector operating temperature. For CPC’s that are to have the flexibility of either east-west or north-south orientation, optimized collectors are shown to have low concentrations of around 1.2, achieved by truncation from acceptance half angles of about 45 deg.

On Optimizing Solar Collectors Orientation Under Daily Nonrandom Cloudiness Conditions

1988 ◽  
Vol 110 (4) ◽  
pp. 346-348
Author(s):  
M. Segal ◽  
R. A. Pielke ◽  
Y. Ookouchi
Keyword(s):  
Solar Radiation ◽  
Solar Energy ◽  
Flat Plate ◽  
Illustrative Case ◽  
Solar Collectors ◽  
Monthly Basis ◽  
Energy Gains ◽  
Geographical Locations

Seasonal daily nonrandom cloudiness is typical in many geographical locations. Optimization of flat-plate solar collectors orientation in such situations requires azimuth and tilt modifications from those when daily cloudiness is random. The present study evaluates the significance of optimizing solar radiation gains, while considerating an illustrative case of nonrandom afternoon/morning cloudiness. Results suggest that for fixed flat-plate collectors the related gain in solar energy is practically insignificant. For nonfixed collectors the solar energy gains can be improved on a monthly basis by up to ∼6 percent.

Low-Concentration CPC’s for Low-Temperature Solar Energy Applications

1986 ◽  
Vol 108 (1) ◽  
pp. 49-54 ◽  
Author(s):  
J. M. Gordon
Keyword(s):  
Low Temperature ◽  
Solar Energy ◽  
Flat Plate ◽  
Quantitative Assessment ◽  
Acceptance Angle ◽  
Flat Plates ◽  
Low Concentration ◽  
Energy Applications ◽  
Material Requirements ◽  
Temperature Applications

We consider the feasibility of low-concentration CPC’s for low-temperature applications. A quantitative assessment of optical gains versus thermal losses, and of savings in reflector area, leads to the conclusion that low-concentration CPC’s of relatively small acceptance angle may be competitive with, or superior to, flat plates. Calculations of yearly collected energy and material requirements are presented, and comparisons are made with corresponding flat plate collectors.

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