DSpace Arşivi :: by Yazar "Ceylan, Ilhan" değerine göre listeleniyor

Yazar "Ceylan, Ilhan" seçeneğine göre listele

Listeleniyor 1 - 20 / 46

The artificial neural network model to estimate the photovoltaic modul efficiency for all regions of the Turkey
(Elsevier Science Sa, 2014) Ceylan, Ilhan; Gedik, Engin; Erkaymaz, Okan; Gurel, Ali Etem
Artificial neural network (ANN) is a useful tool that using estimates behavior of the most of engineering applications. In the present study, ANN model has been used to estimate the temperature, efficiency and power of the Photovoltaic module according to outlet air temperature and solar radiation. An experimental system consisted photovoltaic module, heating and cooling sub systems, proportional integral derivative (PID) control unit was designed and built. Tests were realized at the outdoors for the constant ambient air temperatures of photovoltaic module. To preserve ambient air temperature at the determined constant values as 10, 20, 30 and 40 degrees C, cooling and heating subsystems which connected PID control unit were used in the test apparatus. Ambient air temperature, solar radiation, back surface of the photovoltaic module temperature was measured in the experiments. Obtained data were used to estimate the photovoltaic module temperature, efficiency and power with using ANN approach for all 7 region of the Turkey. The study dealing with this paper not only will beneficial for the limited region but also in all region of Turkey which will be thought established of photovoltaic panels by the manufacturer, researchers and etc. (C) 2014 Elsevier B.V. All rights reserved.
Assessment of a novel defrost method for PV/T system assisted sustainable refrigeration system
(Pergamon-Elsevier Science Ltd, 2022) Karaagac, Mehmet Onur; Ergun, Alper; Gurel, Ali Etem; Ceylan, Ilhan; Yildiz, Gokhan
Energy consumption has continuously increased depending on the rapidly growing human population, enlarging economies, advancing technologies, and improving living standards. A noteworthy share of the energy consumption has been arising from the buildings all across the world. Refrigeration, heating, and air conditioning systems have accounted for a significant portion of the energy consumption in the buildings. Therefore, it is possible to both reduce energy consumption, and mitigate the carbon footprints by efficiently designing, constructing, and operating these systems. In this framework, the present research has centered on the refrigeration systems, and aimed to develop a novel defrost method for photovoltaic thermal (PV/T) assisted sustainable refrigeration systems. In the conventional refrigeration systems, the frost process occurs when air condenses on the evaporator surface as a result of the evaporator surface temperature being below the freezing point of water or the dew point temperature of the air in the conditioned space. Differently in the present work, PV/T system is used to prevent the frost process in the refrigeration system, unlike the conventional systems. Accordingly, the efficiency loss caused by the temperature increment will be prevented by cooling the PV module, and it is aimed to be more efficient by reducing the daily power consumption as an alternative solution method to the frost that occurred on the evaporator in refrigeration systems. On this purpose, a novel evaporator design is developed, and used for defrosting in this study. Accordingly, this novel design includes a refrigerant line inside the evaporator and a hot water line from the PV/T in this design. In the results, it is noticed that the system designed for winter conditions could be used for defrosting. While an average of 605 W for heat energy was used for each defrost process, the average defrost duration was recorded to be approximately 4 min. While the average electrical efficiency of the PV module was found to be 13.6%, the average total efficiency was found to be 38%. Besides, Average PV module surface temperature was determined as 36.4 degrees C, average water storage tank temperature was determined as 26.4 degrees C. In addition, the coefficient of performance (COP) of the refrigeration system is calculated to be 4.18. COP increased by an average of 9% during defrosting. Furthermore, the environmental economic cost was calculated to be 14.6 $/h. In the conclusion, it is proven that the novel defrost method proposed in the present work can be used for refrigeration systems, and contribute to both the reduction of energy consumption and mitigation of carbon emissions arising from the buildings.
Assessment of a solar-assisted infrared timber drying system
(Wiley, 2017) Aktas, Mustafa; Ceylan, Ilhan; Ergun, Alper; Gurel, Ali Etem; Atar, Musa
This study investigates convective-infrared drying characteristics of timber. The biggest disadvantage of infrared heating systems is the uncontrollable rise of the surface temperature up to extremely high values, which causes damage to the product. In this study, the power of an infrared system was controlled and adjusted according to the surface temperature of the product. In doing so, the surface temperature of the infrared heater was prevented from reaching up to values that could damage the product. During the analysis, the surface temperature of the timbers was kept at an average of 65 degrees C, while the bottom temperature was kept at an average of 45 degrees C. The air collector used in the system was found to be 50% efficient. At the end of a 13-h drying period, the moisture content of pine timbers could be reduced from 1.42 to 0.0948 g water/g dry matter. During the system analysis, parameters such as moisture content, mass diffusion coefficient, and useful energy rate were taken into consideration. (c) 2017 American Institute of Chemical Engineers Environ Prog, 36: 1875-1881, 2017
Concentrated photovoltaic and thermal system application for fresh water production
(Pergamon-Elsevier Science Ltd, 2020) Al-Hrari, Muhsen; Ceylan, Ilhan; Nakoa, Khaled; Ergun, Alper
This study was conducted to investigate the performance of Concentrated Photovoltaic/Thermal system (CPV/T) coupled with direct contact membrane distillation (DCMD) for saline water desalination. A numerical heat and mass flux model was constructed to investigate the feasibility of freshwater production. The average electrical efficiency was found to be about 18%, while thermal efficiency increased to an average of 25% and the total efficiency reached an average of 71%. The CPV/T efficiency with the cooling loop reached 19.26% at the peak time of the process. Eventually, the DCMD produced 3 kg/m(2)/h of fresh water and consumed thermal energy of about 9200 kJ/kg water. Moreover, the water mass flux decreased from 3 L/m(2)/h to 1.8 L/m(2)/h in a nonlinear manner. When the gain output ratio (GOR) of the system reaches 2.6 efficiency value or greater, the water outlet temperature from the CPV/T can increase along with the water permeate flux produced by the coupled system. In contrast, if the temperature of the outlet water from the CPV/T system is low, the feed water temperature in the heat exchanger also decreases. As a result, a significant decrease is observed in the feed inlet temperature of the DCMD module.
Cooling of a photovoltaic module with temperature controlled solar collector
(Elsevier Science Sa, 2014) Ceylan, Ilhan; Gurel, Ali Etem; Demircan, Husamettin; Aksu, Bahri
The efficiency of photovoltaic modules decreases with heating, so there has been an increase with regard to the solution of the problem. Photovoltaic module converts the incoming solar radiation into heat and electric energy. Due to this heating feature of photovoltaic modules, it is likely to produce heat energy from PV modules as well. Such systems are called as both a photovoltaic and thermal systems in the literature. A lot of experimental studies were done by special processing on the PV module. Since the studies require special processing on the module, they remain as laboratory work only. In this study, different PV/T systems were experimentally analyzed for the cooling photovoltaic modules. A simple pipe was placed on PV module as a spiral heat exchanger in order to provide active cooling. Also, the system can easily be applied to large-scale systems. As a result of experimental research, the module efficiencies with cooling were calculated as 13%, and the module efficiencies without cooling were about 10%. As the set temperature increased, module temperature can be increased or decreased. The module temperature was changed according to solar radiation and set temperature. As the solar radiation increased the module temperature decreased in this experimental system. The solar radiation has nothing to do with set temperature for this system. (C) 2014 Elsevier B.V. All rights reserved.
Decreasing the Cooking Time of the Dry Beans Without Lowering the Quality
(Gazi Univ, 2015) Aktas, Mustafa; Ceylan, Ilhan; Sevik, Seyfi; Dogan, Hikmet
The aim of this study is to decrease the cooking time of the dry beans without lowering the quality. A second soaking was applied to the dry beans after drying, which were cooked for 2 hours following the first cooking. The dry beans were dried at 40 degrees C drying air temperature after the soaking. The volume of the beans was increased by about 16% through these procedures. Cooking period after the second drying was decreased by 1 hour. Results also showed that there was no split skin on the outer layers of the dry beans, which is a notable quality criterion, owing to the method used while soaking and, soaking and drying operations on the dry beans before packaging decreased the pre-cooking soaking and cooking period. Thus, energy and time saving can be obtained during cooking.
Designing of energy saving system with heat recovery and solar air collector
(Elsevier, 2023) Atas, Safak; Ceylan, Ilhan; Timar, Osman Egemen
In this study, it is aimed to increase the efficiency of heat pump systems, which are generally used for heating in winter. A combined system was created by utilizing the heat pump system, solar air collectors and a heat recovery device. The coefficient of performance of the heat pump system was 6.4 and the efficiency of the solar air collector was 70% while 85% energy efficiency was acquired from the heat recovery device used in the system. The heat recovery device's energy efficiency was calculated as 85%, while the exergy efficiency was calculated as 40%. The usage of these three systems, which has already high energy-efficiency at separately usage, together in one single system has prevented the decreasing that may occur in the energy efficiency of the systems during the day increased their efficiency. The outdoor air temperature in the winter season significantly reduces the efficiency of heat pump systems, and even many systems work defrost mode. The proposed and experimentally studied system, the operability of the heat pump has been ensured throughout the day. For this process, the system has been able to benefit not only from the solar air collector, but also from the energy of heat recovery device.
DESIGNING, MANUFACTURING AND PERFORMANCE EXPERIMENTS OF HEAT PUMP RED PEPPER DRYER ASSISTED SOLAR ENERGY
(Turkish Soc Thermal Sciences Technology, 2010) Aktas, Mustafa; Ceylan, Ilhan; Dogan, Hikmet; Aktekeli, Zuelfikar
In this study, redpeppers were dried in a heat pump dryer assisted solar energy. Redpeppers have been dried from initial moisture content (10.81 g water/g dry matter) to final moisture content (0.16 g water/g dry matter) by using heat pipe solar collector and air to air heat pump system. In the drying system, 24 h drying period was provided heat pump support. In PID controlled dryer, air velocity changed according to the temperature value which is set in process control device. Redpeppers were dried at 50 degrees C dry bulb temperature and average 0.4 m/s air velocity in a period of 210 min. According to experiment results, average heating coefficient performance (COPwh) and specific moisture extraction rate (SMERws) were calculated for whole system as 2.24 and 0.209 kg/kWh respectively.
A detailed analysis of CPV/T solar air heater system with thermal energy storage: A novel winter season application
(Elsevier, 2021) Ceylan, Ilhan; Gurel, Ali Etem; Ergun, Alper; Ali, Ismail Hamad Guma; Agbulut, Umit; Yildiz, Gokhan
The interest in solar energy is increasing day by day because it is clean and limitless. Concentrated photovoltaic and thermal systems (CPV/T) are one of the systems that use in the winter and the summer, attract great attention among solar energy systems. The main purpose of this research is to discuss the capacity of a CPV/T to simultaneously convert solar energy into electrical energy and thermal energy, especially in winter seasons. While only thermal energy is obtained in many concentrated air collectors (CAC) used in the literature, in this study, energy is stored with the help of phase change material (PCM). Ethyl alcohol and water blend were utilized as a working fluid and paraffin wax was also utilized as a PCM. In this study, system performance was handled by applying energy, exergy and environmental economic analyzes. In the results, the average solar radiation was concentrated from 536 W/m(2) to 737 W/m(2). The average overall thermal efficiency and PV module efficiency of the CPV/T were calculated as 73% and 15%, respectively. In other words, the overall system efficiency of the CPV/T was obtained as 88%. The average exergy efficiency of the CPV/T was calculated as 10%. Concerning the environmental aspect, 1.11 kg of CO2 emission per hour into the atmosphere could be prevented by using such a system. In the conclusions, the present paper has reported that the integration of a PCM and air collector into a CPV/T system provided higher energy efficiency in the winter season.
A detailed investigation of the temperature-controlled fluidized bed solar dryer: A numerical, experimental, and modeling study
(Elsevier, 2022) Gurel, Ali Etem; Agbulut, Umit; Ergun, Alper; Ceylan, Ilhan; Sozen, Adnan; Tuncer, Azim Dogus; Khanlari, Ataollah
Solar thermal systems are generally utilized for providing sustainable and environmentally friendly thermal energy that can be used in different applications. In the present study, a temperature-controlled fluidized bed solar drying system along with flat plate and plate with zigzag fins has been designed, manufactured, and experimentally tested. In the first step, the thermal behavior of designed solar air collectors has been numerically modeled. In the next step, the drying system's performance has been experimentally investigated. The overall efficiency of the system was found to be 64%. The maximum exergy efficiency of flat and zigzag plate solar air collectors was calculated as 7.2% and 11.6%, respectively. Then moisture content (MC) and moisture ratio (MR) values were modelled by response surface methodology (RSM), and the predicted results were compared with four metrics. It was found that the drying parameters were highly fitted with the mathematical models. MC metric was predicted with accurate values for performance criteria of R-2, R-RMSE, and MBE as 0.9995, 1.94%, and -0.0096, respectively. The general outcomes of numerical, experimental and modeling analyses of this research exhibited successfulness of the developed the fluidized bed solar drying system.
Determination of drying characteristics of apples in a heat pump and solar dryer
(Elsevier, 2009) Aktas, Mustafa; Ceylan, Ilhan; Yilmaz, Sezayi
Both a heat pump and solar dryer were designed and manufactured. They were experimentally analyzed by drying apples, and a comparison was made between the two. Apples were sliced 4 mm thick, and dried from 4.8 (g water/g dry matter) moisture content to 0.18 (g water/g dry matter) at 3.3 kg/m(2)s-2.4 kg/m(2)s mass air velocity for 15 h in a heat pump dryer. Apples were also dried at the range of 3.3 kg/m(2)s and 2.9 kg/m(2)s mass air velocity from 4.8 (g water/dry matter) moisture content to 1 (g water/g dry matter) moisture content in the same period in a solar dryer. Effective moisture diffusivity was found to be 2.36 x 10(-8) m(2)/s in the heat pump dryer, and 1.03 x 10(-8) m(2)/s in the solar dryer. For both systems, the moisture ratio was analyzed with the Statgraphic program by using semi-theoretical models and compared to the empirical values. Correlation coefficients of the equations were calculated and standard error of estimation (SEE) and R-2 values were obtained.
Determination of Drying Characteristics of Timber by Using Artificial Neural Networks and Mathematical Models
(Taylor & Francis Inc, 2008) Ceylan, Ilhan
In this research, poplar and pine timbers have been dried in heat pump dryer functioning on the basis of 24-h operation. The change in weight in all of the timbers was followed in the drying chamber and drying stopped when the desired weight was achieved. Initial moisture content of the poplar timbers was 1.28kg water/kg dry matter, and the moisture content was reduced to 0.15kg water/kg dry matter moisture content in 70h; the moisture content of the pine timbers, which was 0.60kg water/kg dry matter, was reduced to the same amount in 50h. Drying air temperature, relative humidity, and stack weight were measured and collected during drying and saved on a computer and analyzed afterwards. The moisture ratios were analyzed with Statgraphic computer program by using semitheoretical models and empirical values. Correlation and standard error of estimation (SEE) and R2 values were achieved.
Determination of the heat transfer coefficient of PV panels
(Pergamon-Elsevier Science Ltd, 2019) Ceylan, Ilhan; Yilmaz, Sezayi; Inanc, Ozgur; Ergun, Alper; Gurel, Ali Etem; Acar, Bahadir; Aksu, Ali Ilker
In this study, the efficiency of the rear-panel air velocity in cooling was investigated based on the temperature and solar radiation in the environment where the panels are located. During the cooling of the panels, the rear-panel temperature decreases, and accordingly, the open-circuit voltage of the panels increases. At present, the most important losses in panels are due to the increase in panel temperature depending on the solar radiation and outdoor air temperature. In this study, the rear-panel temperature changes were observed at 0-5 m/s air velocities and 10-40 degrees C. The calculations reveal that in winter weather conditions, the temperature of the panels did not increase at a level that would require cooling. This study investigated the heat transfer from the surface depending on the outdoor air temperature of the rear-panel air velocity and the changing rear-panel temperature. The effect of different outdoor air temperatures on the rear-panel heat transfer is minimal. When the air velocity was 5 m/s and the outdoor air temperature was 10-40 degrees C, the heat transfer in the Poly Crystal Solar panel was calculated as 11.6 W/m(2)K. (C) 2019 Elsevier Ltd. All rights reserved.
Development and Analysis of a Multi-evaporator Cooling System with Electronic Expansion Valves
(Springer Heidelberg, 2017) Atas, Safak; Aktas, Mustafa; Ceylan, Ilhan; Dogan, Hikmet
In this study, a vapor compression cooling system with three evaporators and electronic expansion valves was designed, manufactured and tested experimentally. Compressor of this system was converted to be inverter driven which enabled it to run at variable speeds. Temperature values of cold rooms were controlled more sensitive by using electronic expansion valves. Energy analysis was done by comparing the operating parameters of the system with constant and variable speeds. Programmable logic control (PLC) and cold room controls were used to control the system. The PLC device provided the variable operation of the system by determining the required operation frequency of the compressor according to the changes at the suction line. Using this program, the desired values are set on the PLC screen and the multi-evaporator cooling system was tested at various conditions. The desired conditions are determined for the system at 0,+5 and -5 degrees C temperatures. Calculations on the experimental results revealed that the cooling coefficient of performance is 1.86 for the constant frequency operation and 2.22 for the variable frequency operation. Besides, it was determined experimentally that the system running on variable frequency consumed 20% less electrical energy than the constant frequency system.
THE EFFECT OF MALFUNCTIONS IN AIR HANDLING UNITS ON ENERGY AND EXERGY EFFICIENCY
(Begell House Inc, 2020) Ceylan, Ilhan; Yildiz, Gokhan; Gurel, Ali Etem; Ergun, Alper; Tosun, Abdulkerim
In this study, the effects of malfunctions and problems occurring in the system components of air handling units, which are the main elements of the air conditioning system, on the energy consumption were investigated. Investigations were carried out in 10 air handling units located in 5 different shopping centers of Turkey. The malfunctions and problems that may occur in operation of air handling units were determined and the problems causing the decrease in the efficiency prescribed by the design characteristics were determined. For this purpose, rod-type anemometer measuring the airflow in the air handling unit ducts, propeller-type anemometer, and thermal camera were used to measure air tightness and heat losses in the body structure. Also, the tension control of the belt of the fan motors, which is one of the main components of the energy consumption unit, and the pollution control of the air filter have also been carried out. The flow rate of water circulating in air handling units was determined, and losses were detected by energy and exergy analyses with thermodynamic parameters for summer and winter periods. As a result of the calculations, it was determined that the energy efficiency of the air handling units in the cooling period was 63.7% and the exergy efficiency was 59.6%. The energy loss is 471 kW and the exergy loss is 27 kW in the cooling period. The energy loss is 957 kW and the exergy loss is 127 kW in the heating period. The energy efficiency and the exergy efficiency during the heating period was calculated to be 75% and 41.7%, respectively.
Energy Analysis of a New Design of a Photovoltaic Cell-Assisted Solar Dryer
(Taylor & Francis Inc, 2013) Ceylan, Ilhan; Kaya, Metin; Gurel, Ali Etem; Ergun, Alper
In this study, a new type of solar dryer was designed and manufactured. This new solar dryer is composed of a heat pipe collector, a drying chamber, a load cell, an air circulation fan, photovoltaic cells (PvC), batteries, and halogen lamps. In this experimental study, tomatoes were used to test the drying process. The drying air was heated by the heat pipe collector and forced through the tomatoes by a blower fan during the daytime. The photovoltaic cells, which were used to run the fan, were also used to charge the batteries during the day. These charged batteries were used for running the halogen lamps during the night, when the halogen lamps were used to heat the drying-air-assisted photovoltaic cells. During the drying period, the drying air temperature, relative humidity, air flow rates, solar radiation, and loss of mass were measured in the solar dryer. Then, the measured data were used for energy analysis.
Energy Analysis of Concentrated Photovoltaic/Thermal Panels with Nanofluids
(Int Center Applied Thermodynamics, 2021) Dumrul, Hakan; Yilmaz, Sezayi; Kaya, Metin; Ceylan, Ilhan
In this study, a prototype system was established for location heating application and electricity generation through utilizing two concentrated photovoltaic thermal panels (CPV/T) possessing flat surface receivers connected in series with each other. The purpose of the system is to supply the heating needs of a room in winter season and to meet the electricity requirement of the equipment used in this system. In the analysis of the installed system, different refrigerants (10% mono propylene glycol + 90% water and 0.5% Al2O3-water nanofluid) were tested at three different flow rates (0.4 m(3)/h, 0.5 m(3)/h, 0.6 m(3)/h). Throughout the experiments, the fan-coil air outlet temperature used to heat the room was adjusted to 35 degrees C with an inverter and a process control device. The results attained from the experiments carried out using different fluids throughout different months and days (April-May) have demonstrated that the thermal and electrical efficiencies of the system are found to be in good agreement with each other when evaluated in terms of the fluids utilized. The highest electrical energy recovery was found as 268 W at 0.6 m(3)/h flow rate for propylene glycol-water mixture and 194 W at 0.5 m(3)/ h flow rate for nanomixture. The total thermal energy efficiency for the system using different fluids was found to be around 22%. The total thermal energy gain of the system was also calculated as 2312 W at 0.6 m(3)/h for the propylene glycol mixture and 2041 W at 0.5 m(3)/h for the nanomixture.
Energy analysis of hazelnut drying system-assisted heat pump
(Wiley, 2008) Ceylan, Ilhan; Aktas, Mustafa
In this experimental study, it proportional integral derivative (PID) controlled heat pump dryer wits designed and manufactured. Heat pump dryer was tested drying of hazelnut and energy analyses were made. Drying air temperatures were changed as 50,45 and 40 degrees C in the drying system. Drying air velocities were changed as 0.25 m s(-1) for 50 degrees C, 0.32 m s(-1) for 45 degrees C and 0.38 m s(-1) for 40 degrees C. Heating coefficient of performance of whole system (COPws) of the heat pump dryer was calculated its 1.70 for 50 degrees C, 1.58 for 45 degrees C and 1.40 for 40 degrees C drying air temperatures. Energy utilization ratio changed between 24 and 65% for 50 degrees C, 17 and 63% for 45 degrees C and 14 and 43% for 40 degrees C drying air temperatures in the heat pump dryer. Copyright (C) 2008 John Wiley & Sons, Ltd.
Energy, Exergy and Enviroeconomic (3E) analysis of concentrated PV and thermal system in the winter application
(Elsevier, 2019) Zuhur, Sadik; Ceylan, Ilhan
In this study, a Concentrated Photovoltaic/Thermal (CPV/T) air collector has been designed and a prototype is produced. The purpose of this system is to meet the needs of heating and electricity of the building of application in cold winter days. The prototype which has been produced is tested with and without the use of a concentrator. The data which are obtained are exploited to carry out energy, exergy, and environmental cost analyses. During the experiments, while the average outdoor temperature was measured 10 degrees C, the average chamber temperature was measured as 25 degrees C for a system without a concentrator. As for the systems with a concentrator an average chamber temperature of 35 degrees C has been obtained at approximately the same outdoor temperatures. Increasing panel backing temperature has provided a rise in chamber temperatures in winter. With the use of a concentrator, the panel back side temperatures rise and hence the efficiency of electric power production drops with respect to a system that does not employ a concentrator. However, use of a concentrator increases the thermal and electrical energy gains obtained from the system. Overall thermal energy efficiencies for the concentrated and non-concentrated systems approximately equal to 50%. Efficiencies of thermal energy of systems did not exhibit any variations. However, overall thermal energy gain has been calculated as 220 W for a system that employs a concentrator and 136 W for a system that does not. (C) 2019 Published by Elsevier Ltd.
Energy, exergy and environmental impact analysis of concentrated PV/cooling system in Turkey
(Pergamon-Elsevier Science Ltd, 2019) Zuhur, Sadik; Ceylan, Ilhan; Ergun, Alper
In this study, a Concentrated Photovoltaic Cooling System has been designed and a prototype has been produced. This system is intended to meet the need for cooling and electricity of the building where this system is applied in hot summer days. The produced prototype has been tested with/without using a concentrator. The obtained data was used to analyze the energy, exergy and environmental cost. During performance of experiments, using a concentrator did not affect the thermal energy gain and total thermal energy gain was calculated as approximately 30 W in the system. Besides, use of a concentrator increased the exergy efficiency. Using the concentrator increased the back side temperature of panels, thus electrical performance is lower than the systems without concentrator. The system allows to economize around 0.1 phi per hour due to reduced generation of CO2.

Yazar "Ceylan, Ilhan" seçeneğine göre listele

Sayfa Başına Sonuç

Sıralama seçenekleri