Design Considerations of Unglazed Transpired Collectors: Energetic and Exergetic Studies

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
M. Gholampour ◽  
M. Ameri
Keyword(s):  
Present Model ◽  
Perforated Plate ◽  
Computer Code ◽  
Solar Air Heater ◽  
Effective Parameters ◽  
Energy And Exergy ◽  
Air Ventilation ◽  
Exergetic Analysis ◽  
Exergy Analyses ◽  
Good Agreement

Unglazed transpired collector (UTC) is a kind of solar air heater is used for different applications such as air ventilation, preheating, and crop drying. Passing air through the perforated plate, which acts as an absorber, is the main mechanism of heat transfer and air preheating in UTCs. In order to design UTCs and determine the effective parameters, energy and exergy analyses are performed. A mathematical model which is solved using an iterative method by a computer code has been developed. In order to validate the present model, this solution is compared with numerical and experimental results available in the literature, where a good agreement is obtained. After verifying the model, the code has been used to study the influence of the effective parameters on the performance of the system. The results show that the exergetic analysis is very important to design.

Energy and exergy analyses of a new solar air heater with circular-type turbulators having different relief angles

2016 ◽  
Vol 20 (1) ◽  
pp. 85 ◽  
Author(s):  
Adem Acır ◽  
N.A. �° ◽  
smail Ata ◽  
N.A. �° ◽  
zzet Şahin
Keyword(s):  
Solar Air Heater ◽  
Air Heater ◽  
Energy And Exergy ◽  
Exergy Analyses

Energetic and Exergetic Analysis of the Clay Bricks Drying in an Industrial Tunnel Dryer

2016 ◽  
Vol 369 ◽  
pp. 104-109 ◽  
Author(s):  
G.S. Almeida ◽  
F.V.S. Tavares ◽  
W.M.P.B. Lima ◽  
A.G. Barbosa de Lima
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Moisture Content ◽  
Theoretical Study ◽  
Clay Bricks ◽  
Tunnel Dryer ◽  
Energy And Exergy ◽  
Exergetic Analysis ◽  
Good Agreement ◽  
Hollow Bricks

The purpose of this paper is to present a theoretical study of industrial hollow bricks drying in across flow tunnel dryer. The theoretical model is based on the 1st and 2nd laws of Thermodynamic applied to the system. To validate the methodology, numerical and experimental data of the moisture content of the brick during the drying in an industrial scale are compared and a good agreement was obtained. Results of moisture content and temperature of the product and air, and energy and exergy efficiencies are presented and analysed.

Energetic-exergetic analysis of an air handling unit to reduce energy consumption by a novel creative idea

2019 ◽  
Vol 29 (10) ◽  
pp. 3959-3975 ◽  
Author(s):  
Meysam Yari ◽  
Rasool Kalbasi ◽  
Pouyan Talebizadehsardari
Keyword(s):  
Energy Consumption ◽  
Heat Exchanger ◽  
Computer Code ◽  
Content Type ◽  
Creative Idea ◽  
Air Handling Unit ◽  
Energy And Exergy ◽  
Dry Conditions ◽  
Exergetic Analysis ◽  
Cooling Coil

Purpose This study aims to simulate the flow and heat transfer through an air handling unit to reduce its energy consumption by a novel creative idea of using an air-to-air heat exchanger. Design/methodology/approach To do this, both first and second laws of thermodynamics energy and exergy balance equations were solved numerically by an appropriate developed computer code. Findings Using the air-to-air heat exchanger in dry conditions decreases the cooling coil load by 0.9 per cent, whereas the reduction for humid conditions is 27 per cent. Similarly, using air-to-air heat exchanger leads to an increase in the first law of efficiency in dry and humid conditions by 0.9 per cent and 36.8 per cent, respectively. Originality/value The second law of efficiency increases by 1.55 per cent and 2.77 per cent in dry and humid conditions, respectively. In other words, the effect of using an air-to-air heat exchanger in humid conditions is more than that in dry conditions.

Influence of Rectangular Ribs on Exergetic Performance in a Triangular Duct Solar Air Heater

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Kottayat Nidhul ◽  
Sachin Kumar ◽  
Ajay Kumar Yadav ◽  
S. Anish
Keyword(s):  
Heat Transfer ◽  
Solar Air Heater ◽  
Exergetic Efficiency ◽  
Maximum Enhancement ◽  
Aspect Ratios ◽  
Energy And Exergy ◽  
Overall Performance ◽  
Smooth Plate ◽  
Exergy Analyses ◽  
Exergy Losses

Abstract Several artificial roughness (ribs) configurations have been used in flat plate solar air heaters (SAH) in recent years to improve their overall performance. In the present work, energy and exergy analyses of rectangular ribs in a triangular duct SAH for varying relative rib heights (e/D = 0.02–0.04), relative rib pitches (P/e = 5–15), and rib aspect ratios (e/w = 0.5–4) are evaluated and compared with smooth SAH. The analysis reveals that the entropy generated due to heat transfer is lower for the ribbed triangular duct compared to the smooth duct. It is also observed that the width of the rib plays a crucial role in minimizing heat losses to the environment. A maximum reduction of 43% and 62% in exergy losses to the environment and exergy losses due to heat transfer to the fluid is achieved, respectively, with a rib aspect ratio (e/w) of 4 compared to the smooth plate. It is found that in contrast to the smooth plate, ribs beneath the absorber plate effectively improves thermal and exergetic efficiency. Maximum enhancement of 36% and 17% is obtained in exergetic efficiency (ηex) and thermal efficiency (ηth), respectively, for e/w = 4, P/e = 10 and e/D = 0.04. Results also show the superiority of the ribbed triangular duct over the ribbed rectangular duct for an application requiring compact SAH with a higher flowrate.

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.

Sign in / Sign up

Export Citation Format

Share Document