Energy and exergy analyses of a solar air heater with wire mesh-covered absorber plate

In this paper, eleven roughness elements in solar air heater duct analysed both energy and exergy were reviewed. Various roughness geometries such as ribs, twisted tap, baffles, and metal waste were surveyed about heat transfer and friction when the air flow is passing absorber plate. Evaluation criteria of roughness on the absorber plate including thermohydraulic performance parameter, thermal efficiency, effective efficiency, and exergy efficiency were presented and compared. Results showed that protruded ribs in arc shape indicated the largest Nusselt number. The ribs exhibited the highest thermohydraulic performance parameter at a Reynolds number greater than 5000. Jet impingement with arc-shaped ribs and roughness elements of metal waste were found the smallest exergy efficiencies. The biggest effective and exergy efficiencies were obtained to be 70% and 1.9%, respectively. The thermohydraulic performance parameter varied from 0.5 to 2.0. The review paper aims to provide information about roughness geometries investigated both first and second laws of thermodynamics and figure of merits to overview artificial roughness in a solar air heater.

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Outdoor Testing of a Zig-Zag Solar Air heater with and without Artificial Roughness on Absorber Plate

Journal of Engineering ◽

10.31026/j.eng.2019.04.01 ◽

2019 ◽

Vol 25 (4) ◽

pp. 1-17

Author(s):

Mahmoud Maustafa Mahdi ◽

Ameer Abed Gaddoa

Keyword(s):

Mass Flow ◽

Inclination Angle ◽

Steel Wire ◽

Geographic Location ◽

Operating Conditions ◽

Wire Mesh ◽

Solar Air Heater ◽

Absorber Plate ◽

Air Heater ◽

Inclination Angles

In this paper, thermal performance of a zig-zig solar air heater (ZZSAH) with and without using steel wire mesh on the absorber plate of the collector is experimentally investigated. The experimental work includes four inclination angles of the collector 20o, 30o, 45o, and 60o and four air mass flow rates of 0.03, 0.04, 0.06, and 0.08 kg/s under varieties of operating conditions of a geographic location of Baghdad. New correlation equations of Nusselt number are obtained from experimental results for both types of collectors where the effect of varying of the inclination angle of collector taken into consideration in the experiment. The correlations show good agreement with the present experimental data. In addition, the effects of mass flow rate and temperature rise across the efficiency of collector air heater are investigated. The results reveal that the efficiency of (ZZSAH) at 45o inclination angle reaches the highest values among other degrees of inclination angles for both types of collectors under study. The results also show that the addition of wire mesh magnifies the effect of inclination angle.

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Comparative study based on energy and exergy analyses of a baffled solar air heater with latent storage collector

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2017.11.111 ◽

2018 ◽

Vol 133 ◽

pp. 797-808 ◽

Cited By ~ 31

Author(s):

Amir Ghiami ◽

Shamsoddin Ghiami

Keyword(s):

Comparative Study ◽

Solar Air Heater ◽

Air Heater ◽

Energy And Exergy ◽

Exergy Analyses

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

Journal of Solar Energy Engineering ◽

10.1115/1.4032010 ◽

2015 ◽

Vol 138 (1) ◽

Cited By ~ 7

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.

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