The Thermal Performance of the Two-Pass, Two-Glass-Cover Solar Air Heater

1983 ◽  
Vol 105 (3) ◽  
pp. 254-258 ◽  
Author(s):  
P. Persad ◽  
S. Satcunanathan
Keyword(s):  
Working Fluid ◽  
Solar Air Heater ◽  
Single Pass ◽  
Air Heater ◽  
Glass Cover ◽  
Plate Spacing ◽  
Mode Of Operation ◽  
Predicted Values ◽  
Analytic Models ◽  
Good Agreement

Analytic models are developed for the performance prediction of a two-glass-cover solar air heater operated in both the single-pass and two-pass modes. It is shown that the two-pass mode of operation is superior to the single-pass mode of operation over the range of collector inlet temperatures considered. This is seen to be mainly due to the fact that, in the two-pass mode of operation, the outer glass cover is cooled by the working fluid, thereby reducing the top losses. It is also shown that the performance in the two-pass mode of operation is independent of length, over the range of collector lengths considered, and that a critical plate spacing, dependent on the temperature level of operation of the collector, is indicated. Predicted values of performance are in good agreement with experimental results.

Thermal Performance Analysis of a Rectangular Longitudinal Finned Solar Air Heater With Semicircular Absorber Plate

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Satyender Singh ◽  
Prashant Dhiman
Keyword(s):  
Thermal Performance ◽  
Numerical Solutions ◽  
Solar Air Heater ◽  
Duct Flow ◽  
Balance Equations ◽  
Absorber Plate ◽  
Ansys Fluent ◽  
Air Heater ◽  
Glass Cover ◽  
Good Agreement

Thermal performance of a single-pass single-glass cover solar air heater consisting of semicircular absorber plate finned with rectangular longitudinal fins is investigated. The analysis is carried out for different hydraulic diameters, which were obtained by varying the diameter of the duct from 0.3–0.5 m. One to five numbers of fins are considered. Reynolds number ranges from 1600–4300. Analytical solutions for energy balance equations of different elements and duct flow of the solar air heater are presented; results are compared with finite-volume methodology based numerical solutions obtained from ansys fluent commercial software, and a fairly good agreement is achieved. Moreover, analysis is extended to check the effect of double-glass cover and the recycle of the exiting air. Results revealed that the use of double-glass cover and recycle operation improves the thermal performance of solar air heater.

Exergetic performance evaluation of a single pass baffled solar air heater

Energy ◽  
2014 ◽  
Vol 64 ◽  
pp. 697-706 ◽  
Author(s):  
M. Sabzpooshani ◽  
K. Mohammadi ◽  
H. Khorasanizadeh
Keyword(s):  
Performance Evaluation ◽  
Solar Air Heater ◽  
Single Pass ◽  
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.

scholarly journals Thermal Performance of Three Sided Artificially Roughened Double Duct Parallel Flow Solar Air Heater

2018 ◽  
Vol 7 (1) ◽  
pp. 5-15
Author(s):  
Chander Kant ◽  
Prashant Kumar ◽  
Ankur Gill ◽  
Dhiraj Parkash Dhiman
Keyword(s):  
Heat Transfer ◽  
Reynold Number ◽  
Parallel Flow ◽  
Working Fluid ◽  
Solar Air Heater ◽  
Absorber Plate ◽  
Navier Stokes Equation ◽  
Ansys Fluent ◽  
Air Heater ◽  
Relative Roughness

A solar air heater is basically a heat exchanger, which intercepts the incident solar radiation, converts it into heat and finally transfers this heat to a working fluid for an end use system. The mode of air flowing in the ducts of a solar air heater is one of the most significant aspects concerned with solar air heater which dominantly affect. A double duct parallel flow artificially roughened solar air heater with three sides of the absorber plate is investigated in the current study. Unlike the conventional model of solar air heater with only one sided roughened absorber plate, a novel solar air heater with three artificially roughened absorber plate is used so that the surface area of the absorber plate is increased which ultimately increases the rate of heat transfer. Additionally, a double duct parallel flow arrangement through inner and outer duct of solar air heater is considered order to enhance the heat transfer rate. A numerical investigation of the heat transfer and friction factor characteristics of a double duct parallel flow three sided artificially roughened solar air heater has been carried out. A commercial finite volume CFD code ANSYS FLUENT is used to simulate turbulent air flow through artificial roughened solar air heater. Governing equations of the fluid flow and heat transfer i.e. Navier-Stokes equation and energy equation are solved with RNG k-ε turbulence model. Nine different configuration of square rib are studied with relative roughness pitch (P/e = 5-10) and relative roughness height (e/D = 0.03-0.06). The Reynold number of the flow is varied from 2500 to 16000.

Influence of fin height on the performance of a glazed and bladed entrance single-pass solar air heater

Solar Energy ◽  
2018 ◽  
Vol 162 ◽  
pp. 410-419 ◽  
Author(s):  
A.E. Kabeel ◽  
Mofreh H. Hamed ◽  
Z.M. Omara ◽  
A.W. Kandeal
Keyword(s):  
Solar Air Heater ◽  
Single Pass ◽  
Air Heater

Employing Exergy-Optimized Pin Fins in the Design of an Absorber in a Solar Air Heater

2009 ◽  
Author(s):  
Nwachukwu P. Nwosu
Keyword(s):  
Heat Transfer ◽  
Working Fluid ◽  
Solar Air Heater ◽  
Absorber Plate ◽  
Air Heater ◽  
Heat Transfer Augmentation ◽  
Pin Fins ◽  
Maximum Quantity ◽  
The Cost ◽  
Quantity Of Heat

The performance of a solar air heater is primarily based on the design of the absorber plate and a substantial fraction of the cost of the heater is covered by the cost of the absorber plate. Heat transfer augmentation features for the improvement of heat transfer from the plate to the working fluid are mostly fins however these features also increase pressure drop in the flow channel. The exergy optimization philosophy is adopted in the fin sizing for this air heating application; this optimization philosophy ensures that the maximum quantity of heat is transferred by the fins while generating the least entropy in the system thus conserving exergy. Some important observations relevant in design are made.

Estimation of Non-Linear Damping Parameters in a Normal Triangular Array Subject to Fluidelastic Instability

2006 ◽  
Author(s):  
Craig Meskell ◽  
Petr Eret
Keyword(s):  
Experimental Data ◽  
Limit Cycle ◽  
Triangular Array ◽  
Working Fluid ◽  
Structural Damping ◽  
Non Linear ◽  
Fluidelastic Instability ◽  
Linear Damping ◽  
Predicted Values ◽  
Good Agreement

The non-linear damping parameters associated with a coupled fluidelastic system have been extracted using the non-linear decrement method. The response of a single flexible tube in a five row normal triangular tube array (P/d = 1.32) was recorded over a range of freestream velocities with air as the working fluid. The structural damping has been set so as to avoid fluidelastic instability. The linear and cubic fluidelastic damping parameters have been obtained. Using these identified quantities, the limit cycle amplitudes for the system at lower structural damping levels have estimated. Good agreement between the predicted values and the experimental data is achieved.

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