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.

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.

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.

Using a Windbreak to Improve the Thermal Performance of a Flat Plate Solar Collector: A Feasibility Study

2011 ◽  
Author(s):  
Saeed Moaveni ◽  
Michael C. Watts
Keyword(s):  
Flat Plate ◽  
Heat Loss ◽  
Forced Convection ◽  
Thermal Performance ◽  
Solar Collector ◽  
Large Scale ◽  
Ambient Air ◽  
Absorber Plate ◽  
Wide Range ◽  
Flat Plate Solar Collector

During the past few decades, a wide range of studies have been performed to improve the performance of flat plate solar collectors by either reducing the heat loss from a collector or by increasing the amount of solar radiation absorbed by the absorber plate. Examples of these studies include adding transparent honeycomb to fill the air gap between the glazing and absorber plate to reduce convective heat loss, replacing the air in the gap by other gases such as Argon, Krypton, Xenon and Carbon Dioxide, or adding a chemical coating such as Copper Oxide to increase absorbtance and reduce the emittance of the absorber plate. While these methods improve the collector’s efficiency, they focus primarily on limiting the natural convection that occurs in the collector cavity, or on improving the optical properties of the absorber or glazing. None of these studies have addressed the problem of heat loss due to forced convection to the surrounding ambient air in any detail. Yet, research has shown that forced convection will contribute significantly to the heat loss from a collector. Windbreaks have traditionally been used to direct wind to protect farmland, and to direct wind drifts and sand dunes. Windbreaks also have been shown to provide protection for homes from winter winds which result in reduced heating costs for buildings. While windbreaks have been traditionally used for large scale applications, there is reason to believe that similar benefits can be expected for scaled down applications such as adding a windbreak along side of a flat-plate solar collector. In this paper, we examine the feasibility of using a windbreak to provide a flat plate solar collector protection from the wind in order to improve its performance. A series of experiments were performed wherein the thermal performance of two flat-plate collectors — one without a windbreaker and one with a windbreaker — were measured. The results of these experiments are reported in this paper and the need for further studies to explore different windbreak configurations is discussed.

Experimental Analysis of a Flat Plate Solar Collector System for Small-Scale Desalination Applications

2014 ◽  
Vol 984-985 ◽  
pp. 800-806
Author(s):  
G. Jims John Wessley ◽  
P. Koshy Mathews
Keyword(s):  
Solar Radiation ◽  
Flat Plate ◽  
Heating System ◽  
Maximum Temperature ◽  
Small Scale ◽  
Collector System ◽  
Typical Day ◽  
Flat Plate Solar Collector ◽  
Solar Water Heating System ◽  
Flat Plate Collector

This paper presents the results of the experimental investigation on a solar flat plate collector carried out at Coimbatore, India (11°N Latitude and 74°E Longitude). The collector tubes allowed the water to flow twice across the flat plate collector using a circulating pump during which the water gets heated by the solar radiation received by the absorber. The maximum temperature of water obtained on a typical day in the month of April was 64°C with a solar radiation of 932.2651 W/m2. The available solar radiation strongly influences the temperature gain of the system while the wind velocity plays a considerable role in influencing the heat lost by the system. It is observed that the two-pass flow of water across the absorber plate results in a maximum temperature gain with an overall collector efficiency of 43.7 %. This solar water heating system using flat plate collector can be used for small-scale desalination applications.

Combined Convective-Radiative Thermal Analysis of a Solar Flat-Plate Collector

2015 ◽  
Author(s):  
Aaron P. Eicoff ◽  
Mohammad H. Naraghi
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Heat Fluxes ◽  
Heat Transfer Analysis ◽  
Water Heater ◽  
Solar Water ◽  
Water Heaters ◽  
Flat Plate Solar Collector ◽  
Flat Plate Collector ◽  
Solar Water Heaters

A model for the combined spectral radiative, conductive and convective heat transfer analysis of solar water heaters is presented. The radiation aspect of this model is based on the spectral distribution of the solar irradiance and spectrally selective properties of the system components. The convective equations that were used are based on well-established empirical models. The heat transfer characteristics of the solar water heater are determined by simultaneously solving a nonlinear system of energy balance equations for the various physical components using an iterative approach. The model is used to predict temperatures and heat fluxes for a typical flat-plate solar collector for various geometries and conditions i.e. flow rates, solar irradiances and spectral properties.

scholarly journals Particle Optimization of Ceo2/Water Nanofluids in Flat Plate Solar Collector

2019 ◽  
Vol 9 (2) ◽  
pp. 1467-1474 ◽  
Keyword(s):  
Flat Plate ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Solar Collector ◽  
Volume Concentration ◽  
Particle Volume ◽  
Wide Range ◽  
Flat Plate Solar Collector ◽  
Flat Plate Collector

The present research focuses on the role of CeO2/water nanofluid for estimating the performance of flat plate solar collector in respect of energetic and exergetic performance. Based on our experimental findings on varying mass flow rate, the present analysis focuses on a wide range of concentrations to find optimum volume concentration for which thermal performance is maximum. CeO2/water nanofluid exhibits high thermal conductivity improvement (~41.7%at 1.5% volume concentration) and comparatively lower dynamic viscosity. Performance evaluation of flat plate collector is based on first law analysis and qualitative nature of energy flow based on second law analysis. Experiments indicate that for~1.0% particle volume concentration at a mass flow rate of 0.03 kg/s, maximum collector efficiency is obtained up to 57.1% instead of water as the base fluid. Exergetic efficiency observed 84.6%at optimum concentration (~1.0% particle volume) of nanofluid at0.01 kg/s flow rate.

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