Investigation of solar air collector with offset strip fin absorber plate for drying agricultural products under different climates of Algeria

2015 ◽  
Author(s):  
A. Benseddik ◽  
A. Azzi ◽  
A. K. Allaf ◽  
R. Khanniche
Keyword(s):  
Agricultural Products ◽  
Absorber Plate ◽  
Solar Air Collector ◽  
Offset Strip Fin ◽  
Different Climates

Performance and Economic Analysis of Double Pass Solar Air Collector

2011 ◽  
Author(s):  
Akhilesh Gupta ◽  
Ravi Kumar ◽  
Bharat Ramani
Keyword(s):  
Porous Material ◽  
Economic Analysis ◽  
Thermal Performance ◽  
Convective Heat Transfer Coefficient ◽  
Radiation Energy ◽  
High Heat ◽  
Absorber Plate ◽  
Double Pass ◽  
Plate Temperature ◽  
Solar Air Collector

Solar collector is a type of heat exchanger which transfers solar radiation energy into the heat energy. Conventional solar air collectors have poor thermal efficiency primarily due to high heat losses and low convective heat transfer coefficient between the absorber plate and flowing air stream, leading to higher absorber plate temperature and greater thermal losses. Attempts have been made to improve the thermal performance of conventional solar air collectors by employing various design and flow arrangements. Double pass counter flow solar air collector with porous material in the second air passage is one of the important and effective design improvement that has been proposed to improve the thermal performance. This paper presents the performance and economic analysis of double pass solar air collector with and without porous material. Effects of various parameters on the thermal performance and pressure drop characteristics have been studied experimentally. The study concludes that double pass arrangement with porous material is economical and having short payback period. Also, the thermal performance of double pass solar air collector with porous material is significantly higher compared to double pass solar air collector without porous material and single pass arrangement.

Experimental Investigation of Double Pass Solar Air Collector for Using in Agricultural Applications

2020 ◽  
pp. 98-117
Author(s):  
Mohammed Fahmi ◽  
Wissam Khalil ◽  
Amer Shareef
Keyword(s):  
Thermal Performance ◽  
Winter Season ◽  
Longitudinal Direction ◽  
Absorber Plate ◽  
Double Pass ◽  
Solar Air Collector ◽  
Agricultural Applications ◽  
Good Technique ◽  
Extended Surfaces ◽  
Good Agreement

In this research, an experimental study has been performed in order to enhance the thermal performance of a double-pass solar air collector by employing extended surfaces. In order to increase the heat transfer area, triangular-shaped fins were mounted on the longitudinal direction of the absorber plate. Four models of the solar air collectors were made of aluminum with different fin configurations. The experiments were carried out at the winter season in the climate of Iraq - Ramadi city with longitude 43.268 and latitude (33.43). The used range of mass flow rate in the experiments was from 0.027 kg/s to 0.037 kg/s. The comparison with previous studies in terms of thermal efficiency showed good agreement where the percentage of error does not exceed 1% between them. The results also provided that the existing of fins was a good technique for enhancing the thermal performance of double-pass solar air collector with a marginal increase in pressure drop. Consequently, it is possible to adopt this kind of solar air collectors for many agricultural applications such as solar dryer.

scholarly journals Experimental Performance of Solar Air Heaters for Drying Applications

2021 ◽  
Vol 1 (5) ◽  
pp. 4-10
Author(s):  
Gedion Habtay ◽  
Maytham A. Al-Neama ◽  
Janos Buzas ◽  
Istvan Farkas
Keyword(s):  
Temperature Rise ◽  
Climatic Conditions ◽  
Agricultural Products ◽  
Maximum Temperature ◽  
Drying Rate ◽  
Double Pass ◽  
Experimental Performance ◽  
Single Pass ◽  
Solar Dryer ◽  
Solar Air Collector

This paper presents the results of an experimental investigation on an indirect active type of solar dryer, using two distinct solar air collector and their impacts on drying agricultural products. The thermal performance of the proposed collectors has been evaluated using the first and second laws of thermodynamics. Experimental observations were done in climatic conditions Gödöllő, Hungary on the 2nd and 9th of October 2017. The experiments were also carried out to dry 2 kg of sliced apples spread over the drying trays. The mas flow rate of air was maintained as 0.038 kg/s and the dryer was operated from 10:00 a.m. to 3:00 p.m. When a double-pass solar air collector's results are compared to a single-pass solar air collector's, it's evident that the double-pass solar air collector produces much more energy and efficiency. The experimental results showed that single-pass and double-pass collectors have daily efficiencies of 42.77% and 56.10%, respectively, with average exergy efficiency values ranging from 31% to 49% for single-pass and 51% to 67% for double-pass. The most significant aspect determining the collectors' thermal efficiency was the temperature rise between the collector outlet and inlet. The average drying efficiencies of the solar dryer for the single and double-pass collectors were evaluated as 12.16% and 16.45%, respectively. The maximum temperature rise for double-pass was determined to be 20 °C, whereas single-pass was found to be 6.5 °C. Furthermore, the highest drying rate was achieved when sliced apples were dried with a double-pass collector mode. It reduced 52% of the water content in the apple in the same amount of time as single-pass drying, compared to 35% in the case of single-pass drying.

Design and optimization of a solar air heater with offset strip fin absorber plate

2014 ◽  
Vol 113 ◽  
pp. 1349-1362 ◽  
Author(s):  
Ming Yang ◽  
Xudong Yang ◽  
Xing Li ◽  
Zhifeng Wang ◽  
Pengsu Wang
Keyword(s):  
Solar Air Heater ◽  
Absorber Plate ◽  
Design And Optimization ◽  
Air Heater ◽  
Offset Strip Fin

Thermal performance of a double-pass solar air heater (SAH) with ribbed absorber surface – an experimental study

2020 ◽  
Vol 17 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Nandkishor Sah ◽  
Mohan Jagadeesh Kumar Mandapati
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Flow Rate ◽  
Thermal Performance ◽  
Agricultural Products ◽  
Experimental Investigations ◽  
Absorber Plate ◽  
Content Type ◽  
Solar Intensity ◽  
Passive Techniques

Purpose Use of packed beds, enhanced tubes, nano-fluids and artificial ribs are few passive techniques to increase heat transfer in solar air heaters (SAHs). Artificial ribs attached to the absorber plate of the SAH will enhance the turbulence near the plate. Experimental analyses are conducted to find the thermal performance of SAH with ribs of regular geometries including rectangular, semi-circular and triangular in cross section. This paper aims to present the improvement in thermal performance of SAH with modified-arc. Design/methodology/approach Absorber plates are designed with ribs of rectangular, triangular, semi-circular and modified-arc in cross-section using existing data in literature. Physical dimensions of the ribs are designed by adapting procedure from literature. Absorber plates are manufactured with ribs and coated with blackboard paint and fixed to the existing SAH. Experiments are conducted with a variable-speed blower fixed to the inlet section of the SAH, which is used to supply air at different mass flow rates in a range between 0.495 and 0.557 kg/min. Findings Efficiency is found to be a strong function of mass flow rate of air through the SAH from the present experimental investigations. It was found that use of modified-arc ribs enhanced the efficiency of SAH by 105.35 per cent compared to SAH with plane absorber plate. Efficiency of SAH with modified-arc ribs is found to be higher by 24.43, 45.61 and 63.21 per cent, respectively, for SAH with semi-circular, rectangular and triangular arc ribs on its absorber plate. Research limitations/implications Experiments on SAH are conducted during daytime from 9:00 am to 5:00 pm in open atmospheric conditions. Solar intensity is continuously changing during the experimentation from morning to evening. Calculations are made based on the observations with average values of solar intensity and temperature readings. More accurate values of SAH efficiency can be obtained with constant heat supply to the absorber plate by simulating the experimental setup in indoor conditions. Temperature and flow rate observations could be more accurate with sophisticated instrumentation rather than using simple thermocouples and orifice meters. Social implications SAHs are basically used to supply hot air for both rural and industrial applications. These are used for crop drying, preheating of air, removal of moisture from leather, chemicals, etc. Conventionally, formers in India are using open sun drying to remove moisture from agricultural products. In this method, the moisture can be removed up to a level of 20 to 25 per cent. Use of SAH can remove moisture up to below 5 per cent and process is clean without reducing the quality of agricultural products. Enhancing the efficiency of SAHs will surely increase its usage by formers for crop drying. Originality/value Use of artificial ribs on absorber plate of SAH is most economical among many of the active and passive techniques. Numerical and experimental investigations are found in literature with regular cross-sectional ribs, including rectangular, triangular and semi-circular. The present work proposed new shape of the ribs named as modified-arc, which was not presented in the literature. Experimental analysis proved that the use of modified-arc makes the SAH more efficient in heat transfer.

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