Browsing by Author "Sirin, Ceylin"

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Drying Municipal Sewage Sludge with V-Groove Triple-Pass and Quadruple-Pass Solar Air Heaters Along with Testing of a Solar Absorber Drying Chamber
(Elsevier, 2020) Khanlari, Ataollah; Sozen, Adnan; Afshari, Faraz; Sirin, Ceylin; Tuncer, Azim Dogus; Gungor, Afsin
Everyday a large amount of sewage sludge is produced in cities and proper and environmentally friendly municipal wastewater treatment is needed. Finding a convenient and affordable way for sewage sludge refinement to reduce environmental pollution or even utilization of sewage sludge will be a very attractive challenge for scientists. In the recent years, sustainable and renewable energy sources like solar energy are extensively utilized in different fields including heating, electricity generation, and drying applications. In this study, V-groove triple-pass (V-TPSAH) and V-groove quadruple-pass (V-QPSAH) solar air heaters have been designed, manufactured and tested for drying municipal sewage sludge. Also, two different types of drying chambers (DC-I: conventional, DC-II: solar absorber) have been integrated with each solar heater. Experimental and numerical methods have been applied to analyze the efficiency of developed solar air heater assisted drying systems. The system's performance has been tested in different working conditions to clarify the utilization potential of manufactured system. According to the experimental results solar air heater's average efficiency are in the range of 70.12-81.70%. In addition, obtained experimental findings are in line with numerical results. The outcomes of this study present the potential of using the developed systems in drying municipal sewage sludge to be used in multi purposes. (C) 2018 Elsevier B.V. All rights reserved.
Effect of Turbulator Modifications on the Thermal Performance of Cost-Effective Alternative Solar Air Heater
(Pergamon-Elsevier Science Ltd, 2020) Afshari, Faraz; Sozen, Adnan; Khanlari, Ataollah; Tuncer, Azim Dogus; Sirin, Ceylin
Over the past years, there has been a huge growth in the solar energy research, development and progress, due to being a renewable, economical and non-polluting energy source. In this research, different design and placement of turbulators inside a cost-effective tube-type solar air heater (TSAH) has been analyzed to upgrade thermal performance. Both experimental and CFD analysis have been performed in order to survey the performance of solar heating systems. Numerical method has been done by utilizing Fluent program in order to simulate real models and also verified with experimental results. It is proposed to improve the thermal efficiency of TSAH by integrating turbulators in different modifications. According to the experimental outcomes maximum instantaneous heater efficiency was reached to 72.41%. Also, experimental and numerical average temperature difference values in TSAHs varied in the range of 9.16-14.54 degrees C and 9.50-14.95 degrees C, respectively. The experimental and numerical simulation results exhibited successful design of this simple and inexpensive alternative hot air generation system. Manufactured simple-structured TSAHs in the present work have acceptable thermal performance in comparison to more complex solar heaters in the literature. This type of solar heater could be used in different applications such as; drying, greenhouse heating, space heating and air preheating. (C) 2020 Elsevier Ltd. All rights reserved.
Empirical Investigation of Small-Scale Aluminium Wool Packed Solar Air Heater Made with Waste Material
(Gazi Univ, 2021) Khanlari, Ataollah; Tuncer, Azim Dogus; Sirin, Ceylin; Afshari, Faraz; Gungor, Afsin
Waste production is an important problem for the developing world and globalization. The waste materials can be reused through recycling process and its environmental effects can be minimized. Utilizing renewable energy sources at the maximum level is also an important issue for a sustainable development in future as well as waste management. In this study, small-scale solar air heating systems were produced from waste materials to analyze the usability of waste material in renewable energy systems. Scrap metal elbows were used in the production of heaters. The first solar heater is hollow (SH) and the second one was modified by filling it with aluminum wool (SHAW). Both heaters were tested simultaneously at different flow rates (0.014, 0.010 and 0.006 kg/s). According to the experimental results, the thermal efficiency values for SH and SHAW were found in the range of 33.63-42.90% and 42.69-56.98%, respectively. In addition, it was observed that a low cost modification such as using aluminum wool can significantly increase thermal performance of the solar heating system.
Experimental and CFD Survey of Indirect Solar Dryer Modified with Low-Cost Iron Mesh
(Pergamon-Elsevier Science Ltd, 2020) Guler, Hande Ozge; Sozen, Adnan; Tuncer, Azim Dogus; Afshari, Faraz; Khanlari, Ataollah; Sirin, Ceylin; Gungor, Afsin
In the present work, double-pass indirect solar dryer (DPISD) and double-pass indirect solar dryer with mesh absorber modification (DPISDMA) have been designed, analyzed, manufactured and tested. The main aim of this study is improving the thermal efficiency of double-pass solar air collector by integrating iron meshes. Pepino fruit (Solarium muricatum L.) samples in two thicknesses have been used in the experimental study. Also, CFD analysis of both solar air collectors and drying chamber and quality metrics such as phenolic, total flavonoid contents and antioxidant activity have been conducted. Numerical simulation and experimental results showed that using mesh modification has positive influence on the performance of the collector. The highest value of the average efficiency of the dryer was obtained in DPISDMA for the thin sample thickness as 23.08%. According to quality analyses, the experiments which done in DPISDMA gave the best results with highest values of TPC, TFC and antioxidant activity values (p < 0.05). Drying data of the pepino fruit for different experiments were modelled according to 8 different most used mathematical models. Accordingly, the best fitted kinetics model was determined as Logarithmic model for all experiments which gave the most accurate statistical values.
Testing of a Novel Convex-Type Solar Absorber Drying Chamber in Dehumidification Process of Municipal Sewage Sludge
(Elsevier Sci Ltd, 2020) Tuncer, Azim Dogus; Sozen, Adnan; Afshari, Faraz; Khanlari, Ataollah; Sirin, Ceylin; Gungor, Afsin
Each day high portion of municipal wastewater sludge is generated in cities and developing a suitable and environmentally friendly treatment technique for municipal wastewater is required. Providing a cost-effective and suitable way for sewage sludge refinement with the purpose of reducing environ-mental impacts or reutilization of sewage sludge can be an important issue for researchers. In the present study, a novel convex-type solar absorber assisted dryer has been designed for drying municipal sewage sludge. In the experimental setup, an unglazed single-pass solar air collector has been used as main air heater and integrated to the drying conventional and modified drying chambers. Experimental and CFD simulation have been used to investigate the performance of fabricated solar energy assisted dryers. Also, the effectiveness of the developed system has been analyzed in various conditions to clarify the potential of fabricated dryers. According to the results utilizing convex solar absorber led to provide high air flow rate with high temperature inside the drying chamber and consequently shortened the drying time. Experimentally obtained average energy efficiency of the modified and conventional indirect solar drying system were in the range of 32.85-47.09% and 21.32-30.45%, respectively. Moreover, the experimental results collected from CSD (conventional solar dryer) and CSASD (solar dryer with convex solar absorber) are also discussed in terms of R-2, RMSE, RRMSE, MBE, and MAPE, and a very satisfying correlation be-tween the systems CSD and CSASD is noticed with the statistical metrics. The findings of the present study demonstrate the potential of utilizing the designed dryers in drying municipal wastewater sludge. (C) 2020 Elsevier Ltd. All rights reserved.