Yazar "Amini, Ali" seçeneğine göre listele

Listeleniyor 1 - 3 / 3
  • [ X ]
    Öğe
    Developing an infrared-assisted solar drying system using a vertical solar air heater with perforated baffles and nano-enhanced black paint
    (Pergamon-Elsevier Science Ltd, 2023) Tuncer, Azim Dogus; Amini, Ali; Khanlari, Ataollah
    In the present study, it is aimed to improve the performance of a solar drying system (SDS) utilizing ZnO nano-enhanced absorber coating and infrared heating system. In the first stage of this work, different geometrical configurations of the main heating system of the SDS which is a vertical solar air heater (VSH) have been numerically analyzed. According to the numerical findings, VSH with perforated type baffles gave the best performance results. Then, the determined configuration has been manufactured and combined with a drying chamber. Moreover, two other modifications have been applied to the system including an infrared heater and nano-enhanced black paint. In other words, the experimental part of this research contains three SDS types including a conventional SDS, a SDS with infrared heater and a SDS with infrared heater and ZnO nano-enhanced absorber coating (combined usage of two modifications). The mean thermal and exergetic efficiencies of the VSH analyzed within the scope of this work were attained between 53.54-65.12% and 9.94-14.32%, respectively. Moreover, combined use of infrared heater and nano-enhanced absorber coating material in the VSH decreased the drying time period as 43.75% when compared to the unmodified SDS.
  • [ X ]
    Öğe
    Experimental and numerical analysis of a helically-coiled solar water collector at various angular placements
    (Elsevier France-Editions Scientifiques Medicales Elsevier, 2023) Variyenli, Halil Ibrahim; Amini, Ali; Tuncer, Azim Dogus; Khanlari, Ataollah; Kolay, Sahin
    Solar water collectors are widely utilized for providing hot water to be used in different applications. In this work, a solar water collector with a helically coiled absorber has been designed, fabricated, and examined at different test conditions to specify its overall performance. One of the major goals of using a tube-type absorber is to upgrade the thermal efficiency of the collector by providing a perpendicular angle between the absorber and incident solar rays. Also, using a helically-coiled structure make it possible to increase the absorber surface in a relatively small volume in comparison to conventional solar water collectors. In the first step of this research, the designed helically-coiled solar collector has been simulated using a solar radiation model. In the next step, the manufactured helically-coiled solar collector has been experimentally tested at three different inclination angles and various water flow rates. According to the experimental results, mean thermal efficiencies of horizontal, vertical, and angular helically-coiled collectors were obtained in the ranges of 29.48-48.23%, 27.17-47.03%, and 32.50-52.71%, respectively. In addition, sustainability index values for horizontal, vertical and angular helically-coiled collectors were achieved between the ranges of 1.0041-1.0091, 1.0039-1.0087, and 1.0043-1.0102, respectively. Moreover, the maximum deviation between numerical and experimental findings was calculated as 14%.
  • [ X ]
    Öğe
    Experimental and transient CFD analysis of parallel-flow solar air collectors with paraffin-filled recyclable aluminum cans as latent heat energy storage unit
    (Elsevier, 2023) Tuncer, Azim Dogus; Amini, Ali; Khanlari, Ataollah
    In the present study, it is aimed to improve the overall performance of a parallel-flow solar air collector (PSC) using phase change material (PCM)-based latent heat energy storage unit and recyclable materials. In the simulation part of this work, two PSCs including a collector without modification and a collector equipped with PCM filled aluminum cans have been analyzed. The simulation part of the current work is handling the flow of air through the collectors and melting-solidification of PCM material inside the aluminum cans. Considering the simulation study results, three different PSC configurations have been manufactured including an unmodified PSC, a PSC with PCM-filled aluminum cans on the front side of the absorber and a PSC with PCM-filled aluminum cans on both sides (back and front) of the absorber surface. According to the results of the analyses, utilizing PCM-filled aluminum cans in both surfaces of the absorber plate of the PSC improved numerically and experimentally obtained exergetic efficiency values as 61.70% and 74.03%, respectively. Moreover, enviro-economic analysis has been conducted within the scope of this work. The payback periods of the analyzed systems were between 2.17 and 2.43 years. Employing PCM in the both sides of the absorber surface decreased the payback time of the system as 10.69% in comparison to the conventional PSC. Moreover, using PCMs on the single and double side of the absorber plate improved the annual carbon dioxide savings as 22.68% and 35.42%, respectively.