Yazar "Khanlari, Ataollah" seçeneğine göre listele

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    Analysis of drying of melon in a solar-heat recovery assisted infrared dryer
    (Elsevier Ltd, 2016) Aktaş, Mustafa; Şevik, Seyfi; Amini, Ali; Khanlari, Ataollah
    Infrared drying systems are popular in terms of high heat and mass transfer. By using an infrared dryer, it is possible to catch fast heating and short drying time in comparison to the other drying methods. But it consumes a high amount of energy. Therefore, a new type solar air collector (SAC) and air to air heat recovery unit were added to the infrared dryer to reduce specific energy consumption. The general aim of this study is to analyze heat and mass transfer characteristics of the dryer and three-dimensional (3-D) computational fluid dynamic (CFD) simulation and to investigate drying kinetics of melon slices. Experiments were performed at 50 °C and 60 °C melon’s surface temperature and 0.5 m/s air velocity. Melon slices were dried from 9 g water/g dry matter to 0.044 g water/g dry matter moisture content. The effective moisture diffusivity (De) values varied from 8.25 × 10?10 to 1.24 × 10?9 m2/s. The average mass transfer coefficient (hm) values increase from 8.53 × 10?8 m/s at 50 °C to 1.47 × 10?7 m/s at 60 °C. Heat recovery unit has a key role in this system and it provides 23–28% of total input energy. Average solar air collector efficiency was calculated as 50.6%. Obtained theoretical and experimental results are in line with each other. This study shows the successful and efficient combination of solar energy, infrared energy and heat recovery in food processing.
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    Modeling of a convective-infrared kiwifruit drying process
    (Elsevier Ltd, 2017) Özdemir, M. Bahadır; Aktaş, Mustafa; Şevik, Seyfi; Khanlari, Ataollah
    This paper aims to evaluate the experimental performance of a convective-infrared system with heat recovery (CIRHR) at different drying temperatures (40, 45, 50 and 55 °C) and 0.5 m/s air velocity and also to discuss and predict the performance of system on energy consumption and drying kinetics of sliced kiwifruit using artificial neural networks (ANNs). The energy efficiency values were obtained between 2.85% and 32.17%. The ANN model was used to predict the energy consumption of the system and moisture content of the kiwifruit. The back-propagation learning algorithm with Levenberg–Marquardt (LM) and Fermi transfer function were used in the network. The coefficient of determination (R2), the root means square error (RMSE) and the mean absolute percentage error (MAPE) were calculated as 0.99, 0.001 and 0.34, respectively. It can be concluded that predicted values are in good agreement with experimental results. © 2017 Hydrogen Energy Publications LLC
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    Öğe
    Performance analysis of heat pump and infrared–heat pump drying of grated carrot using energy-exergy methodology
    (Elsevier Ltd, 2017) Aktaş, Mustafa; Khanlari, Ataollah; Amini, Ali; Şevik, Seyfi
    In this study, a hybrid drying system that combines all of the advantages of different drying methods was developed. This study aims to compare experimental results of a heat pump dryer (HPD) and an infrared assisted heat pump dryer (IRAHPD), to determine the energy and exergy efficiency of dryers and to analyze the drying kinetic of grated carrot for observing the effectiveness of the dryers. Samples were dried at 45 °C and 50 °C set temperatures and 0.5 m/s air velocity. According to dry basis calculation, initial moisture content amount was 7.06 g water/g dry matter and amount of final moisture content of dry matter was obtained as 0.14 g water/g dry matter. Energy efficiency varied between 5.3% and 50%. Minimum and maximum coefficients of performance for the whole system (COPws) were 2.11 and 2.96 respectively. Maximum exergy efficiency was obtained 66.8% while minimum exergy efficiency was 31.6%. It was concluded that during the time to reach a stable state of system, the exergy efficiency increased in response to exergy loss decreases. This study shows a successful and efficient combination of heat pump and infrared heater in food drying. © 2016 Elsevier Ltd