FLOW AND HEAT TRANSFER STUDIES IN A DOUBLE – PASS COUNTER FLOW SOLAR AIR HEATER

2013 ◽  
Vol 31 (02) ◽  
pp. 37-42
Author(s):  
S. Singh
Keyword(s):  
Heat Transfer ◽  
Solar Air Heater ◽  
Double Pass ◽  
Counter Flow ◽  
Air Heater ◽  
Flow And Heat Transfer

PERFORMANCE ANALYSIS OF DOUBLE PASS COUNTER FLOW SOLAR AIR HEATER FOR DRYING APPLICATION

2018 ◽  
Author(s):  
D.V.N. Lakshmi ◽  
Palanisamy Muthukumar ◽  
Dr.Apurba Layek ◽  
Abhimanyu Kumar Singh ◽  
Sushoban Das
Keyword(s):  
Performance Analysis ◽  
Solar Air Heater ◽  
Double Pass ◽  
Counter Flow ◽  
Air Heater

Evaluating the Performance of a Modified Solar Air Heater With Pierced Cover and Packed Mesh Layers

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Raheleh Nowzari ◽  
Hasan Saygin ◽  
L.B.Y. Aldabbagh
Keyword(s):  
Airflow Rate ◽  
Solar Air Heater ◽  
Centrifugal Fan ◽  
Construction Costs ◽  
Double Pass ◽  
Counter Flow ◽  
Single Pass ◽  
Air Heater ◽  
Current Design ◽  
Thermohydraulic Efficiency

Abstract An experimental study was conducted to evaluate the thermal efficiency of a modified solar air heater. In the current design, air enters the collector through holes in front glass, passes through mesh layers, and exits at the backside of the air heater. A centrifugal fan was used to circulate air through the system. The design offers low construction costs and less solar radiation reflected from the collector. The modified collector was examined with various bed heights (30, 50, and 70 mm) and different mass flowrates of air varying from 0.011 kg/(s m2) to 0.043 kg/(s m2). The results showed that a counter flow collector with pierced cover had 5.6–9.7% higher efficiency than the single-pass one. The average efficiencies of the current design collector were found to be 55.2%, 44.6%, and 39.7% for the single-pass and 60.8%, 50.9% and 45.4% for the double-pass collector at 30, 50, and 70 mm bed heights and airflow rate of 0.043 kg/(s m2), respectively. The thermohydraulic efficiency, temperature difference, and perforated cover surface temperature were analyzed at each test and their effects on the system performance were evaluated. The highest amount of pressure drop through the collector was measured in the collector with a 70-mm bed height and a maximum air flowrate.

Performance evaluation of a new counter flow double pass solar air heater with turbulators

Solar Energy ◽  
2018 ◽  
Vol 173 ◽  
pp. 398-406 ◽  
Author(s):  
A.S. Abdullah ◽  
M.M. Abou Al-sood ◽  
Z.M. Omara ◽  
M.A. Bek ◽  
A.E. Kabeel
Keyword(s):  
Performance Evaluation ◽  
Solar Air Heater ◽  
Double Pass ◽  
Counter Flow ◽  
Air Heater

Simulation of Flow and Heat Transfer in Triangular Cross-Sectional Solar-Assisted Air Heater

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Rajneesh Kumar ◽  
Anoop Kumar ◽  
Varun Goel
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Roughness Parameter ◽  
Solar Air Heater ◽  
Governing Equations ◽  
Cross Sectional ◽  
Air Heater ◽  
Flow And Heat Transfer ◽  
Finite Volume Approach ◽  
D Values

The ribbed three-dimensional solar air heater (SAH) model is numerically investigated to estimate flow and heat transfer through it. The numerical analysis is based on finite volume approach, and the set of flow governing equations has been solved to determine the heat transfer and flow field through the SAH. For detailed analysis, rib chamfer height ratio (e′/e) and rib aspect ratio (e/w), two innovative parameters, have been created and considered along with the commonly used roughness parameter, i.e., relative roughness height, e/D. The parameters e′/e, e/w, and e/D are varied from 0.0 to 1, 0.1 to 1.5, and 0.18 to 0.043, respectively, but the value of P/e is kept constant for the entire investigation at 12. A good match is seen in Nusselt number (Nu) and friction factor (f) by comparing the predicted results with the experimental ones. With the variation of roughness parameters, distinguishable change in Nu and f is obtained. The highest value of thermohydraulic performance parameter (TPP) observed is 2.08 for P/e, e′/e, e/w, and e/D values of 12, 0.75, 1.5, and 0.043, respectively, at Re of 17,100. The developed generalized equation for Nu and f has shown acceptable percentage deviation under the studied range of parameters.

Innovatively Arranged Curved-Ribbed Solar-Assisted Air Heater: Performance and Correlation Development for Heat and Flow Characteristics

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Rajneesh Kumar ◽  
Abhishek Singh Kashyap ◽  
Paramvir Singh ◽  
Varun Goel ◽  
Khushmeet Kumar
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Roughness Element ◽  
Flow Characteristics ◽  
Solar Air Heater ◽  
Quasi Steady State ◽  
Air Heater ◽  
Relative Roughness ◽  
Flow And Heat Transfer ◽  
Gap Width

Abstract Solar radiation is a rich and clean source of energy. It can be collected and converted to thermal energy with the help of flat plate collectors called the solar-assisted air heater. Because of the low coefficient of heat transfer of air, the solar-assisted air heater has low thermal performance which can be improved by creating local turbulence using surface roughness on the heat transferring plate. The present investigation has been conducted to perceive the influence of the curved-ribbed element with gap on flow and heat transfer. The roughness element is defined by using five non-dimensionlized parameters, i.e., relative roughness width (W/w), relative roughness pitch (P/e), relative gap width (g/e), relative roughness height (e/D), and relative gap distance (d/x). The radius of the curvature of the curved rib-element is kept constant and the experimental measurements were done under quasi-steady state. The thermohydraulic performance parameter improved by 3.61 times the smooth flat plate solar air heater (SAH), in curved-ribbed SAH for W/w = 3, P/e = 8, g/e = 1, e/D = 0.045, and d/x = 0.65 at Reynolds number of 23,000. The generalized relation for heat transfer and flow characteristics is also being developed and the predicted Nusselt number and friction factor with the accuracy of ± 7.5% and ± 6.7%, respectively.

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