Yazar "Cerci, Kamil Neyfel" seçeneğine göre listele

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    Comprehensive modelling of rotary desiccant wheel with different multiple regression and machine learning methods for balanced flow
    (Pergamon-Elsevier Science Ltd, 2021) Guzelel, Yunus Emre; Olmus, Umutcan; Cerci, Kamil Neyfel; Buyukalaca, Orhan
    In this paper, several alternative models were developed with multiple linear regression and machine learning algorithms to determine the output states of silica gel desiccant wheels for balanced flow. The decision tree method was used for this purpose for the first time in open literature. All the models developed include six input parameters and a wider range than those available in the literature. Predictions from the models were compared with the master dataset used to derive the models, each of the five sub-datasets that make up the master dataset and with data available in the literature. It was determined that the most suitable models are those coded as multiple linear regression-IV (MLR-IV), multilayer perceptron regressor-III (MLPR-III) and decision tree-VII (DTVII), and DT-VII is the best among them. The determination coefficient and root mean square error for temperature were found to be 0.9894 and 0.8743 degrees C for MLR-IV, 0.9817 and 1.1526 degrees C for MLPR-III, 0.9986 and 0.3295 degrees C for DT-VII, respectively. The corresponding values for humidity ratio were 0.9912 and 0.3701 g kg(-1) for MLR-IV, 0.9885 and 0.4227 g kg(-1) for MLPR-III, 0.9994 and 0.0995 g kg(-1) for DT-VII, respectively. The results obtained revealed that the proposed models can be used safely in preliminary design, simulation and dynamic energy analysis of systems with desiccant wheels.
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    Effect of operating parameters on the performance of rotary desiccant wheel energized by PV/T collectors
    (Yildiz Technical Univ, 2023) Olmus, Umutcan; Guzelel, Yunus Emre; Cerci, Kamil Neyfel; Buyukalaca, Orhan
    The main energy input of a desiccant air conditioning system is the low-quality thermal energy required for regeneration, which can be obtained from waste heat, geothermal resources or solar energy. Regeneration thermal energy can be produced as well as energizing components such as fans, pumps, auxiliary air heaters, and control elements of the system by using photovoltaic-thermal solar collectors (PV/T). In this study, parametric analyzes were performed to investigate the effect of regeneration temperature and air frontal velocity on the temperature and dehumidification performance of a solid silica-gel desiccant wheel and on the water-cooled PV/T collectors used to provide the regeneration thermal energy. The regeneration temperature was varied between 50 and 70 degrees C, and air frontal velocity between 1.3 and 4.1 m/s. The analyzes show that the dehumidification efficiency increases from 13.94% to 33.04% as regeneration temperature increased from 50 degrees C to 70 degrees C at 1.3 m/s air frontal velocity at which dehumidification efficiency is maximum. At 4.1 m/s air frontal velocity, the required regeneration thermal energy is maximum and increases from 49.64 kW to 132.48 kW at the same regeneration temperature change. The low regeneration temperature resulted in desirable latent performance and undesirable sensible heat transfer performance in DEW. Finally, considering the whole system, it was concluded that the optimum regeneration air temperature for the performance parameters is 60 degrees C.
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    Experimental and Modeling Study of Peanut Drying in a Solar Dryer with a Novel Type of a Drying Chamber
    (Taylor & Francis Inc, 2022) Hurdogan, Ertac; Cerci, Kamil Neyfel; Saydam, Dogan Burak; Ozalp, Coskun
    The aim of the present study is to investigate the experimental performance of a solar dryer by using a novel type of a drying chamber for increasing the drying performance and ensuring homogeneous drying. The drying system (SDS) consisted of a new type of a drying chamber and a solar air collector, which were designed, made, and tested in Osmaniye, Turkey. The analyses of Computational Fluid Dynamics were carried out to demonstrate the advantage of the designed drying chamber over the tunnel type drying chamber, which is commonly used in peanut drying. The drying experiments were conducted using in-shell peanut to observe the performance of the system. The drying procedure was performed in the form of open sun drying (OSD), and the results of drying kinetics such as moisture ratio (MR), drying rate (DR), and heat transfer coefficient (h(c)) obtained from both drying methods were compared. The MR and DR values obtained during the drying experiments were estimated using different models such as mathematical, multiple linear regression (MLR), decision tree (DT), and the support vector machine (SVM). It was observed from the numerical results that the products can dry more homogenously and effectively with the newly designed drying chamber compared to the conventional tunnel type drying chamber. The results of the drying experiments showed that the products dried earlier and more regularly through the SDS compared to the OSD. The DR and h(c) values were found 0.0051E-01 (g(w)/g(dm))/min and 1.5727 W/m(2)degrees C for SDS and 0.0039E-01 (g(w)/g(dm))/min and 1.4664 W/m(2)degrees C for OSD, respectively. The models that best estimated the experimentally obtained MR and DR values for peanuts dried with the SDS proved to be the Random Tree Model (R-2 = 0.9972) and Quintic Model (R-2 = 0.8551), respectively.
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    Experimental investigation and artificial neural networks (ANNs) based prediction of thermal performance of solar air heaters with different surface geometry
    (Pergamon-Elsevier Science Ltd, 2024) Cerci, Kamil Neyfel; Saydam, Dogan Burak; Hurdogan, Ertac; Ozalp, Coskun
    Solar air heaters (SAHs) are one of the most utilized tools to obtain heat energy from the sun. A variety of SAH models exist with different geometries used for improving the heat transfer between the absorber plate and the air in the SAHs. In today ' s world, many researchers are focusing on designs that occupy the same dimensions but can generate more useful energy. In this study, two SAH with the same external volume (same base area and height), but different absorber surface geometries: a V -corrugated type (V -Type) and an internal baffle -installed type (B -Type), were designed, manufactured and experimentally tested in the climatic conditions of Osmaniye, T & uuml;rkiye. B -Type SAH, unlike the literature, is constructed with 11 inner baffles to allow the air to circulate more within the collector, aiming to achieve higher temperatures. The performances of the SAHs were compared by means of energy, exergy and enviro-economic (3E) analyses in the experiments lasting four consecutive days without interruption. The results show that the average amount of useful heat, energy efficiency ( eta I ) and exergy efficiency ( eta II ) of the V -Type SAH was 35.71%, 38.00% and 80.11% higher, respectively, than those obtained with the B -Type SAH, and also that the V -Type SAH was more environmentally friendly than the B -Type SAH. Additionally, in this study, common ANN models predicting the performance parameters of both SAHs were developed, constituting the another novelty of the research. Among the common ANN models developed for the outlet temperature ( T o ) , besides the eta I and eta II parameters, the best results were obtained with ANN 15, ANN 13 and ANN 18, respectively. Therefore, it is possible to use these developed models safely.
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    Investigation of the energetic and exergetic performance of hybrid rotary desiccant-vapor compression cooling systems using different refrigerants
    (Pergamon-Elsevier Science Ltd, 2024) Cerci, Kamil Neyfel; Silva, Ivo Rafael Oliveira; Hooman, Kamel
    In this study, a desiccant-based hybrid cooling system supported by a vapor compression system and a heat recovery unit (rotary heat wheel) was analyzed from energetic and exergetic perspectives during the daily working hours of an office building in Istanbul to meet the desired comfort conditions. We focus on the impact of different refrigerants; namely R32, R1234yf, R290, R134a, R600a, R245fa, and R717, on hybrid rotary desiccantvapor compression systems. While the highest electricity consumption was obtained in the system using R1234yf, the lowest electricity consumption was achieved with R717. However, with the effectiveness of the desiccant wheel, the best results were obtained for R1234yf with those pertinent to R717 at the other extreme. Considering the total electricity consumption of the system, the highest energetic and exergetic performance parameters were achieved with the use of R717 as the refrigerant. Compared to R1234yf, the daily average energetic performance parameters obtained with R717 increased by 22.3 % for COPr, 21.8 % for COPel, and 4.7 % for COPth. Similarly, compared to R1234yf, the daily average exergetic performance parameters in R717 presented increases of 13.6 % for COPx,el, 7.5 % for COPx,th, and 8.1 % for eta x.
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    Numerical analysis and comparison of different serpentine-based photovoltaic-thermal collectors
    (Pergamon-Elsevier Science Ltd, 2025) Olmus, Umutcan; Guzelel, Yunus Emre; Cerci, Kamil Neyfel; Buyukalaca, Orhan
    This study investigated the performance of 25 serpentine-based photovoltaic-thermal (PVT) collector configurations using numerical modeling with COMSOL Multiphysics software. The analysis compared single-inlet, double-inlet and triple-inlet configurations, with tubes arranged both horizontally and vertically, while maintaining constant geometric properties. Some of the configurations examined were studied for the first time in the open literature. The analyses were conducted in two stages. First, all configurations were compared under base- case conditions using various energetic and exergetic performance metrics. The results revealed that configurations K1 and M, which are novel, and configuration B demonstrated superior performance. Second, the effects of water inlet temperature, flowrate, and solar irradiance on the temperature distribution and efficiency metrics were evaluated for the top three performing configurations. The findings showed that these configurations exhibited similar trends in response to changes in operating conditions. Specifically, increasing the flowrate significantly enhanced thermal, electrical, and primary energy saving efficiencies, while higher water inlet temperatures led to reductions in all efficiency metrics. Moreover, pressure drop decreased as the number of inlets increased. The research emphasizes the importance of selecting a design to enhance the performance of PVT collector based on the various performance metrics.
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    Numerical investigation and ANN modeling of performance for hexagonal boron Nitride-water nanofluid PVT collectors
    (Elsevier, 2023) Buyukalaca, Orhan; Kilic, Haci Mehmet; Olmus, Umutcan; Guzelel, Yunus Emre; Cerci, Kamil Neyfel
    In this study, performance of hexagonal boron nitride (hBN)/water nanofluid used as a coolant in a PVT collector for the first time in the open literature was numerically analyzed based on various input parameters. Numerical analyzes were carried out by varying the flow rate between 14.5 and 43.4 l/h, solar radiation intensity between 200 and 1000 W/m2, hBN nanoparticle volumetric ratio between 0 and 0.22% and nanoparticle diameter between 20 and 80 nm. The results revealed that the thermal efficiency increases up to 0.18 volumetric ratio and then decreases, while the electrical efficiency continuously increases as the volumetric ratio increases. Additionally, an increase in the volumetric ratio leads to an improvement in all exergy parameters. The utilization of 20 nm diameter hBN nanoparticles results in an increase of 0.7%, 3.01%, 2.71%, and 1.80% in electrical, thermal, overall, and exergy efficiency, respectively, in comparison to pure water. In addition to the numerical analysis conducted with hBN/water nanofluid, simulations were also performed for graphene/water nanofluid, which is commonly studied for PVT collectors in the literature, and it was shown that the former exhibits better performance than the latter, albeit to a minimal extent. Finally, two different sets of ANN models were developed to predict five performance parameters of the PVT collector using hBN/water nanofluid. In the first set, each model predicted only one of the five performance parameters, while in the second set, a single ANN model predicted all output parameters. Different numbers of neurons and training functions were tested in the ANN models, and the Feed Forward Backpropagation algorithm was used as the training algorithm for all the models. Additionally, Logsig and Purelin transfer functions were used for the hidden and output layers, respectively. The proposed models were able to successfully reproduce the performance parameters.
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    Performance assessment of a heat pump assisted rotary desiccant dryer for low temperature peanut drying
    (Academic Press Inc Elsevier Science, 2022) Cerci, Kamil Neyfel; Hurdogan, Ertac
    This study presents the investigation of a drying system in which both a desiccant wheel and a heat pump could be used together for low temperature agricultural food product drying. In the system, it was aimed to reduce the moisture content of the drying air to very low levels by using two dehumidification processes together, thus drying the product in a shorter time at low temperature. A model was formed to analyze the system according to different parameters. Peanuts, which are not suitable for high-temperature drying, were selected as the drying product. It has been observed that the system proposed in this study (System I) has a higher performance compared to other desiccant/heat pump drying systems with different configurations (System II-IV). The drying performance index (COPD) increases by 23% in System I compared to System II, while specific energy consumption (SEC) decreases by 19%. In the case of drying air with low humidity (at 5.22 g(w) kg(da)(-1)), the drying performance parameters improve as drying time decreases, although the power consumed by the compressor increases. From the analysis, it has been determined that the optimum rotational speed of the solid desiccant wheel, which is one of the basic elements of the system, is 10 RPH under conditions considered in this study. The results show that COPD decreases as the SEC increases during the drying process, which is because the food product tends to dry at a decreasing rate. The proposed system is suitable for use in low-temperature food drying applications. (C) 2022 IAgrE. Published by Elsevier Ltd. All rights reserved.
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    Predicting process and regeneration air conditions in LT3 molecular sieve desiccant wheels using machine learning and regression methods
    (Pergamon-Elsevier Science Ltd, 2025) Guruk, Alperen Burak; Guzelel, Yunus Emre; Olmus, Umutcan; Cerci, Kamil Neyfel; Buyukalaca, Orhan
    The performance of desiccant wheels is influenced by various design and operational variables. Existing models in the literature for LT3 molecular sieve desiccant wheels often include only a limited number of input parameters or have restricted operating ranges. This study addresses these limitations by generating a dataset encompassing 32,975 scenarios, which was used to develop 192 models using four methods such as multiple linear regression (MLR), decision tree (DT), support vector machine (SVM), and multilayer perceptron (MLP). The models were categorized into two groups to allow for various analyses. Group A models predict the process air outlet conditions of the desiccant wheel, namely temperature (Tpo) and humidity (omega po). Group B models, in contrast, predict the required regeneration air inlet temperature (Tri) necessary to achieve a desired process air exit humidity (omega po), while also predicting Tpo. MLP models demonstrated the best accuracy across both groups. In Group A, the model coded as MLP-7 achieved an RMSE of 0.2017 degrees C for Tpo, and MLP-6 yielded an RMSE of 0.0656 g/kg for omega po. In Group B, MLP-7 recorded an RMSE of 0.1764 degrees C for Tpo, while Tri had an RMSE of 0.7892 degrees C. Additionally, in Group A, the models coded as RS, 3rdCross, DT-28, and SVM-5 also delivered reliable results, while in Group B, the RS, 2ndCross, 3rdCross, DT-28, and SVM-3 models performed well.
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    Summer period analysis of the rotary desiccant - hybrid cooling system combined with solid oxide fuel cells using human waste fuel
    (Elsevier, 2024) Cerci, Kamil Neyfel; Silva, Ivo Rafael Oliveira; Kaska, Onder; Hooman, Kamel
    This paper proposes and simulates a desiccant air cooling system integrated with a vapor compression cooling unit and a heat recovery unit for an office building in & Ccedil;anakkale, Turkey, during the summer season. The required electrical energy for equipment of the proposed system is supplied by an Solid Oxide Fuel Cells (SOFC) unit using human waste as fuel. Moreover, some of the waste heat generated by the SOFC is used to regenerate the desiccant wheel. The simulation also includes the effects of three different refrigerants for the vapor compression cooling unit. Among the refrigerants, the highest electrical COP was obtained for the system using R1234ze(Z), which is 3.14% and 2.40% higher than the systems using R717 and R1233zd(E), respectively. Additionally, the system using R1234ze(Z) achieved electrical savings of 9.97% and 9.23% compared to the other systems. These electrical savings resulted in fuel savings of 1.19% and 0.90% for R1234ze(Z) compared to R717 and R1233zd(E), respectively. During the summer season, the electricity production from the existing SOFC unit met 82.00% of the total electricity consumption of the desiccant hybrid cooling system. Furthermore, a difference of 3984.56 kWh in primary energy consumption was identified between the desiccant hybrid cooling systems operating with the SOFC and without the SOFC during the summer season.
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    The Effects of Shriveling up Waste Watermelons in Different Solar Drying Systems on Withering and Relevant Microbial Parameters
    (Inst Tecnologia Parana, 2023) Cerci, Ibrahim Halil; Durusoy, Omer Faruk; Cerci, Kamil Neyfel
    This study aimed to examine the shriveling parameters and some aerobic microbial qualities of waste watermelons in a combined solar energy drying system (CDS) and an open sun drying system (OSDS). Results showed that the CDS was better than the OSDS in terms of the temperature, relative humidity, surface temperature, time, and speed of reaching the target humidity level of the air-shriveled watermelon slices. The number of mesophilic aerobic bacteria (log10 cfu/g) increased in the shriveled (P>0.05) silages compared to fresh watermelon slices in the CDS and OSDS groups and decreased in silages (P<0.05). Compared to fresh watermelon slices, yeast count (log10 cfu/g) decreased in the shriveled CDS group (P>0.05) and increased in the OSDS group (P>0.05) and was not detected in silages. No mold was determined in the fresh watermelon slices and silages in the CDS and OSDS groups. However, mold was found to be higher in the shriveled slices in the OSDS group than in the CDS group (P<0.05). Aflatoxin was not detected in the fresh, shriveled and silage watermelon slices. As a result, it was determined in this study that the CDS group was more advantageous in terms of slaking parameters compared to the OSDS group in the shriveling process of the waste watermelon slices, which had not been previously studied. It was observed that there was no significant difference between the two systems in terms of aerobic microbial quality determined during the wilting and ensiling process.