Analytical Equation for the Top Heat Loss Factor of a Flat-Plate Collector With Double Glazing

1991 ◽  
Vol 113 (2) ◽  
pp. 117-122 ◽  
Author(s):  
S. K. Samdarshi ◽  
S. C. Mullick
Keyword(s):  
Flat Plate ◽  
Heat Loss ◽  
Loss Factor ◽  
Analytical Equation ◽  
Empirical Equations ◽  
Transfer Coefficients ◽  
Computational Errors ◽  
The Individual ◽  
Flat Plate Collector ◽  
Semi Empirical

An analytical equation for the top heat loss factor of a flat-plate collector with double glazing has been developed. The maximum computational errors resulting from the use of this equation are plus or minus three percent compared to numerical solution of the heat balance equations. The equation is considerably more accurate than the currently used semi-empirical equations over the entire range of variables covered. It is found that the computational errors resulting from simplification of the proposed equation by approximation of the individual heat-transfer coefficients are much lower than the errors resulting from the use of semi-empirical equations.

Generalized Analytical Equation for the Top Heat Loss Factor of a Flat-Plate Solar Collector With N Glass Covers

1994 ◽  
Vol 116 (1) ◽  
pp. 43-46 ◽  
Author(s):  
S. K. Samdarshi ◽  
S. C. Mullick
Keyword(s):  
Flat Plate ◽  
Heat Loss ◽  
Loss Factor ◽  
Analytical Equation ◽  
Empirical Equations ◽  
Additional Advantage ◽  
Computational Errors ◽  
Flat Plate Solar Collector ◽  
Flat Plate Collector ◽  
Semi Empirical

A generalized analytical equation for the top heat loss factor of a flat-plate collector with one or more glass covers has been developed. The maximum computational errors resulting from the use of the analytical equation with several simplifications are ± 5 percent compared to numerical solution of the set of heat balance equations. The analytical equation is considerably more accurate than the available semi-empirical equations over the entire range of variables covered. An additional advantage of the proposed technique over the semi-empirical equations is that results can be obtained for different values of sky temperature, using any given correlation for convective heat transfer in the air gap spacings, and for any given values of fluid (air in the present case) properties.

An Improved Technique for Computing the Top Heat Loss Factor of a Flat-Plate Collector With a Single Glazing

1988 ◽  
Vol 110 (4) ◽  
pp. 262-267 ◽  
Author(s):  
S. C. Mullick ◽  
S. K. Samdarshi
Keyword(s):  
Flat Plate ◽  
Heat Loss ◽  
Loss Factor ◽  
Empirical Relation ◽  
Iterative Solution ◽  
Maximum Error ◽  
Analytical Form ◽  
Plate Temperature ◽  
Glass Cover ◽  
Semi Empirical

A different approach to evaluate the top heat loss factor of a flat plate solar collector with a single glass cover is proposed. The equation for the heat loss factor in the analytical form is employed instead of the semi-empirical form hitherto employed for solar collectors. The glass cover temperature is, however, estimated by an empirical relation. (This relation replaces the empirical relation for the factor f of the earlier work). Values of the top heat loss factor calculated by this simple technique are within 3 percent (maximum error) of those obtained by iterative solution of the heat balance equations. There is an improvement in accuracy by a factor greater than five over the current semi-empirical equations. The range of variables covered is 50° C to 150° C in absorber plate temperature, 0.1 to 0.95 in absorber coating emittance, and 5 W/m2C to 45 W/m2C in wind heat-transfer coefficient. The effect of variation in air properties with temperature has been taken into account.

scholarly journals Thermal analysis of a serpentine flat plate collector and investigation of the flow and convection regime

2019 ◽  
Vol 23 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Dimitrios Korres ◽  
Christos Tzivanidis
Keyword(s):  
Flat Plate ◽  
Current Model ◽  
Flow Simulation ◽  
Special Kind ◽  
Theoretical Models ◽  
Temperature Fields ◽  
Piping System ◽  
Transfer Coefficients ◽  
Inclination Angles ◽  
Flat Plate Collector

A special kind of flat plate collectors was examined in detail through CFD analysis. The distinctiveness of the current model has to do with the piping system was applied which is a serpentine flow conduit. The operation of the collector was examined at four different inclination angles (0?, 15?, 30?, and 45?) and several values of the inlet water temperature (10-80?C per 10?C) by providing the same heat perpendicular to the cover in each case. The thermal efficiency as well as the temperature fields of the collector was determined first. Furthermore, the overall heat losses were calculated and compared to these arisen from the Cooper-Dunkle assumption while the mean divergence between these two solutions was around 5%. Moreover, the natural convection inside the gap as well as the tube to water convection was examined and the heat transfer coefficients were validated from theoretical models in horizontal position. In particular, the simulation results found to diverge from the theoretical ones about 12.5% and 7% as regards the pipe flow and the air-gap, respectively. In addition, a remarkable flow phenomenon was observed at the bends of the pipe and the nature of it was explained in detail. Last but not least, the inclination angle seems that affects significantly the collector?s performance since the higher the slope the lower the convection losses. Solidworks and its simulation program Flow Simulation were used to design and simulate the whole collector.

scholarly journals Optimization of Inclination Angle of Cavity and Characteristics of Attached Fins on the Absorber for Performance Enhancement of Solar Collectors

2021 ◽  
Vol 12 (3) ◽  
pp. 216-221
Author(s):  
A. D. Gupta ◽  
◽  
Ashish Gupta ◽  
P. K. Mishra ◽  
Yashi Gupta ◽  
...  
Keyword(s):  
Natural Convection ◽  
Free Convection ◽  
Flat Plate ◽  
Heat Loss ◽  
Inclination Angle ◽  
Convection Heat ◽  
Solar Collectors ◽  
Aspect Ratios ◽  
Simpler Algorithm ◽  
Flat Plate Collector

This research investigation was undertaken in ANDUAT, Kumarganj, Ayodhya, Uttar Pradesh, India to study the numerical optimization of natural convection heat suppression in a solar flat plate collector with straight fins. Optimal characteristics of an array of thin fins attached on the absorber plat were obtained by Particle Swarm Optimization algorithm (PSOA). Free convection considered dominant in the cavity. Governing equations contained continuity; momentum and energy are discretized by finite volume method. The medium is considered incompressible, whose free convection is dominant and Boussinesq approximation is applied. A simplified model of real systems is applied with free convection. Free convection problem is solved by SIMPLER algorithm. Two confined cavities with aspect ratios 30 and 60 are considered as flat plate solar collectors. The results indicate that significant reduction on the free convection heat loss can be obtained from solar flat plate collector by using plate fins, and an optimal plate fins configuration exit for minimal natural convection heat loss for a given range of Rayleigh number. Reduction of up to a maximum of 25% at 0 inclination angle was observed in aspect ratio 30. Results showed PSOA is able to obtain characteristics of attached adiabatic fins on the absorber plate also it can obtain optimal inclination angle of cavity to decrease heat losses from solar collectors. The results obtained provide a novel approach for improving design of flat plate solar collectors for optimal performance.

Determination of Losses & Loss Coefficients of Solar Flat Plate Collector when Wind Velocity & Tilt Angle at Zero Value – An Experimental Study

2013 ◽  
Vol 376 ◽  
pp. 294-298
Author(s):  
M.K. Bhatt ◽  
B.M. Sutaria ◽  
S.N. Gaderia ◽  
S.A. Channiwala
Keyword(s):  
Experimental Study ◽  
Solar Energy ◽  
Flat Plate ◽  
Heat Loss ◽  
Tilt Angle ◽  
Major Part ◽  
Energy Measurement ◽  
Loss Coefficients ◽  
Flat Plate Collector

The flat plate collector is one of the most widely used device for harnessing solar energy. Measurement of various losses occurring in a flat plate collector is important for design as well as evaluation for efficiency under different conditions. The major part of overall heat loss is the top heat loss. The various losses such as bottom loss, side loss, edge loss, corner loss, sealing loss & top loss etc, are measured as well as recorded. There are forty eight thermocouples located at different points.

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