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Öğe Advanced exergy analysis of an integrated solid waste fueled cogeneration system based on organic Rankine Cycle for different working fluids(Pergamon-Elsevier Science Ltd, 2022) Ustaoglu, Abid; Torlakli, Hande; Ergun, Alper; Erdogmus, Ertugrul; Akay, Mehmet EminIn this study, the performance evaluation of an ORC-based solid waste-powered cogeneration system was carried out using conventional and advanced exergy analysis methods. Eight different working fluids including dry (isopentane, n-pentane, n-octane, n-heptane), isentropic (R141b, R123), and wet (methanol, water) types were selected for the evaluation. The total capacity of the heat source was determined with the data obtained from the assessment of municipal solid wastes with different calorific values by the characterization method. Energy and exergy analyses were carried out for each component to examine the effect of selected cycle parameters, including evaporator pressure, intermediate pressure, and condenser pressure, and determine the optimum working fluid for the system. The exergy destruction in the components was split into avoidable/unavoidable and endogenous/exogenous parts in the advanced exergy analysis to identify the improvement potentials and the interaction between the components. The thermal and exergy efficiency values reach the highest values of 81.36 % and 40.76 %, respectively. R141b performs as the best working fluid, while the lowest performance is obtained from water. About 121.3 kW of power generation and 918.2 kW of process heat were obtained from the ORC-CHP system using R141b at 1400 kPa evaporator pressure. Conventional exergy analysis states that the evap-orator, process heater, and turbine are the most critical components, accounting for 67.94 %, 19 %, and 4.92 % of the total exergy destruction rate, respectively. The advanced exergy analysis shows that the priority should be on the turbine having the largest share of the avoidable part. The avoidable part, which accounts for 14.5 % of the total exergy destruction, can be reduced by system improvements.Öğe 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, GokhanEnergy 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.Öğe Assessment of a solar-assisted infrared timber drying system(Wiley, 2017) Aktas, Mustafa; Ceylan, Ilhan; Ergun, Alper; Gurel, Ali Etem; Atar, MusaThis 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, 2017Öğe Concentrated photovoltaic and thermal system application for fresh water production(Pergamon-Elsevier Science Ltd, 2020) Al-Hrari, Muhsen; Ceylan, Ilhan; Nakoa, Khaled; Ergun, AlperThis 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.Öğe Current practices, potentials, challenges, future opportunities, environmental and economic assumptions for Turkiye's clean and sustainable energy policy: A comprehensive assessment(Elsevier, 2023) Agbulut, Umit; Yildiz, Gokhan; Bakir, Huseyin; Polat, Fikret; Bicen, Yunus; Ergun, Alper; Gurel, Ali EtemIn today's world, most countries including Turkiye have met their electricity demand at a dominant rate by burning fossil-based fuels in thermal power plants. However, fossil-fuel reserves have been rapidly depleted, resulting in high volatility in these fuels' markets, as well as alarming environmental, and economic problems for the governments. In recent years, many governments have started to face these problems and have rapidly transitioned to renewable and alternative carbon-free energy sources in their electricity production variety. However, these belated steps have failed to mitigate the increment in global greenhouse gas emissions against the rapid growth of population and energy demand. In recent years, Turkiye has put a noteworthy challenge to mitigate its dominant use of fossil fuels, reducing its energy dependence, sustaining its economic development, and mitigating the carbon footprint. From this point of view, it is witnessed that many power plants have been established, many of them are currently under construction, especially to produce more electricity in a sus-tainable way. Accordingly, the present study aims to comprehensively discuss Turkiye's energy production policy, energy potential and reserves, challenges, future opportunities, and the impacts of the energy sector on the economic and environmental issues for the country. In this framework, it is well-noticed that the country's future energy production policy has been reasonably changed in order to achieve positive economic and envi-ronmental outcomes in the medium and long term.Öğe A detailed analysis of a novel auto-controlled solar drying system combined with thermal energy storage concentrated solar air heater (CSAC) and concentrated photovoltaic/thermal (CPV/T)(Pergamon-Elsevier Science Ltd, 2023) Benlioglu, Muhammet Mustafa; Karaagac, Mehmet Onur; Ergun, Alper; Ceylan, Lhan; Ali, Ismail Hamad GumaIn recent years, the use of solar energy, one of the renewable energy sources, has been increasing in many areas due to its practical, environmental, and economic benefits. Besides, the drying industry is an applied area where solar energy can be implemented. Solar drying systems are used in the industry to reduce high drying costs and to obtain better quality products. In this study, a novel solar drying system was designed by combining concen-trated solar air collector (CSAC) and concentrated photovoltaic/thermal system (CPV/T). In addition, the automation system has been integrated for data acquisition from the system and humidity-temperature control of the drying chamber. The SAC's inlet air was preheated by a heat exchanger using thermal energy from the PV/T. The drying system has been designed to be more useful by using phase change material in the collector. Thus, the drying process can be performed on cloudy days and after sunset. In addition, the designed system can generate electricity from the PV module to meet the electricity requirement. The mint which grows in various regions worldwide was chosen as the product to be dried in this study. Mint was dried from the first moisture content of 3.3125 g water/g dry matter to the last moisture content of 0.0625 g water/g water/g dry matter. Besides, the average overall efficiency of the system, PV module electrical efficiency, and drying efficiency were found to be 61%, 10%, and 26%, respectively. Furthermore, the average system exergy efficiency, PV module exergy effi-ciency, and concentrated solar air heater exergy efficiency values were calculated as 20%, 16%, and 21.9%, respectively. In the experiment, the ambient average temperature was 22 degrees C, while the average drying chamber temperature was 30 degrees C. The mint drying quality efficiency was 67% on average at this drying chamber tem-perature. The energy, exergy efficiency, and sustainability index of the system were calculated as 61%, 38.8%, and 1.69, respectively. Moreover, the enviro-economic cost of the system was determined to be 0.39 (SIC)/h.Öğe 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, GokhanThe 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.Öğe 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, AtaollahSolar 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.Öğe 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 IlkerIn 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.Öğe 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, AbdulkerimIn 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.Öğe Energetic, exergetic, and thermoeconomic analyses of different nanoparticles-added lubricants in a heat pump water heater(Elsevier, 2022) Yildiz, Gokhan; Agbulut, Umit; Gurel, Ali Etem; Ergun, Alper; Afzal, Asif; Saleel, C. AhamedThe heat pumps are frequently used in domestic and industrial applications for hot water supply. The present paper aims to thermodynamically investigate the impacts of the nanoparticle-addition into the lubricants on the energetic, exergetic, and thermoeconomic aspects of a heat pump. In the experiments, air to the water heat pump is separately charged with various metal oxide-based nanoparticles (Al2O3, CuO, and TiO2)-added oils at a constant mass fraction of 0.5%. Polyolester (POE) and 134a are used as a lubricant, and refrigerant, respectively. The mass flow rates of the water passed through the condenser are varied from 10 to 25 g/s with an interval of 5 g/s. In the results, it is observed that the thermal conductivity value noteworthy increases with the presence of nanoparticles in POE. The highest increment in thermal conductivity is found to be 39% for POE + CuO in comparison with that of pure POE. Furthermore, with nanoparticles addition, it is noticed that the COP value generally improves, and the highest improvement for COP value is noticed to be 8% for POE + TiO2 nanolubricant at the mass flow of 25 g/s. Furthermore, exergy efficiency enhances by 3.6%, 1.8%, and 4.5% for POE + Al2O3, POE + CuO, and POE + TiO2, respectively. The lowest heating cost is calculated to be 3.465 c/kWh at 20 g/s flow rate for POE + Al2O3. In conclusion, this paper clearly reports that usage of nanoparticles along with lubricants is presenting better energetic, exergetic, and thermoeconomic results rather than the usage of lubricant alone in the heat pumps.Öğe 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, AlperIn 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.Öğe Energy and exergy analysis of a PV/thermal storage system design integrated with nano-enhanced phase changing material(Inderscience Enterprises Ltd, 2020) Ergun, AlperNanotechnology and heat storage applications are among the most popular fields of the researchers in recent years. In this study, three different CPV/T systems were analysed experimentally under the same conditions for four days. While no modifications on the CPV were made in the first system, the rear of the panel used in the second system was covered with a phase changing material (PCM). In the third system, together with PCM, nano-sized aluminium oxide (Al2O3) particle in a weight percentage of 5% was added into the system (namely, nano-enhanced PCM). The experimental analysis revealed that 8% more power output and module efficiency were obtained from the system with the PCM and the nano-enhanced PCM compared to the normal system. These systems which were also designed with a heat storage have an average of 42 W thermal energy gain. As the exergy analysis results show, the exergy destruction of the system with the nano-enhanced PCM was found to be lower than that of the PCM system, while exergy efficiency was found to be 14% higher in the former system.Öğe Energy and exergy analysis of surface water source heat pump system(Gazi Univ, 2023) Kocakulak, Serkan; Yilmaz, Sezayi; Ergun, AlperIn this study, energy and exergy analyzes were carried out to heat an experimental room with 28 square meter area by a surface water source heat pump (SWSHP) in the heating season, where placed in next to a river source (Arac stream) in Karabuk University. The system had a frequency inverter to change the compressor speed and the experiment was started at 35 Hz. in winter condition and completed when the indoor temperature reached 25.degrees C. While the COP value of the system was calculated as 2.58 on average, the highest exergy destruction was determined as 0.6 kW in the compressor in terms of the exergy analysis. The average exergy destructions were determined as 0.125 kW for the condenser, 0.152 kW for the expansion valve, 0.14 kW for the evaporator and fan coil system, and 0.06 kW for the water source heat exchanger. Exergy efficiencies were 60% for the compressor, 75% for the condenser, 85% for the expansion valve, 25% for the evaporator, 63% for the fan coil system and 8% for the water source heat exchanger. As a result of the study, it has been determined that the surface water source heat pump system works successfully in Karabuk province conditions.Öğe Energy, exergy and environmental impact analysis of concentrated PV/cooling system in Turkey(Pergamon-Elsevier Science Ltd, 2019) Zuhur, Sadik; Ceylan, Ilhan; Ergun, AlperIn 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.Öğe ENERGY, EXERGY, AND ENVIRONMENTAL (3E) ASSESSMENTS OF VARIOUS REFRIGERANTS IN THE REFRIGERATION SYSTEMS WITH INTERNAL HEAT EXCHANGER(Begell House Inc, 2020) Gurel, Ali Etem; Agbulut, Umit; Ergun, Alper; Yildiz, GokhanA comprehensive thermodynamic analysis of a refrigeration system with an internal heat exchanger was reported for four various refrigerants as an alternative to R134a. The preferred refrigerants in this paper have zero ozone-depleting potential and fairly low global warming potential value compared with reference R134a. These refrigerants are from both the HC group (R290 and R600a) and the HFO group (R1234yf and R1234ze(E)). Basically, the refrigeration system consists of a compressor, condenser, evaporator, expansion valve, and internal heat exchanger as well. Energy-exergy analyses and environmental impact assessments depending on the compressor energy consumptions are evaluated in the current study. The system performance was theoretically carried out at two different evaporation temperatures of 0 and -8 degrees C. Based on the obtained results from this study, the highest performance was achieved in R600a from HC group refrigerants and R1234ze(E) from HFO group refrigerants. As compared with R134a, in the COP value of R600a an increase of 3.2% at the evaporation temperature of 0 degrees C and 3.4% for the evaporation temperature of -8 degrees C was achieved. On the other hand, the COP value for R1234yf was decreased by 2% at the evaporation temperature of 0 degrees C and by 2.57% at the evaporation temperature of -8 degrees C. Considering the CO2 emissions, R600a was located at the first order in terms of the lowest CO2 emissions and R1234ze(E) follows R600a. In conclusion, R600a presented the highest performance compared with R134a in a refrigeration system with an internal heat exchanger.Öğe Energy-exergy-ANN analyses of solar-assisted fluidized bed dryer(Taylor & Francis Inc, 2017) Ergun, Alper; Ceylan, Ilhan; Acar, Bahadir; Erkaymaz, HandeIn this study, a temperature-controlled solar air collector was designed and tested for drying. Solar drying systems have two disadvantages. First one is the lack of ability to store energy and the second one is the lack of temperature control. This study presents the experimental analysis of an air collector that is able to keep the drying air temperature at 40 degrees C even in cases where the level of solar radiation received by the collectors changes. Most of the tests were performed at a solar radiation level ranging from 500 to 900W/m(2) and at an air flow of 3 to 5m/s. The system tested for drying three different crops separately performed 21h of a total of 27-h drying period at or above the temperature set of 40 degrees C. The thermodynamic analysis of the relationship between solar radiation, air temperature, flow, and the produced energy was performed. The relationship between productivity, energy produced, and set temperature was analyzed using distribution charts. Moreover, an artificial neural network model was used to estimate outlet air temperature from the solar collectors based on air flow, solar radiation, and outside air temperature.Öğe Enhancing the performance of parabolic trough solar collectors: Cost-effective innovative designs for sustainable energy harvesting(Pergamon-Elsevier Science Ltd, 2024) Karaagac, Mehmet Onur; Akinci, Burak; Ergun, AlperThis study aims to improve the performance and stability of parabolic trough solar collectors (PTSC), especially those with heat storage capacity. Three different receiver tube designs have been meticulously developed to achieve this goal. As a result of the research, the Black surface (BS) -PTSC and PTSC- Paraffin wax (PW) systems achieved 26.5% and 56.8% more thermal energy flow, respectively, compared to the conventional PTSC. In addition, while the average thermal efficiencies of the PTSC, BS-PTSC, and PTSC-PW systems were found to be 11.2%, 14.1%, and 16.9%, respectively, the average exergy efficiencies of the PTSC, BS-PTSC, and PTSC-PW were 1.4%, 1.9%, and 2.3%. Painting the black copper pipe and filling the receiver tube with paraffin wax PCM increased thermal and exergy efficiency. Besides, comparing the temperature differences based on the PTSC system, it was found that BS-PTSC and PTSC-PW systems have 12.3% and 16.4% higher tank temperatures, respectively. The findings of this research have demonstrated the potential of parabolic trough solar collectors equipped with heat storage. It has also increased the sustainability index in terms of sustainability and reduced CO2 emissions into the atmosphere. Furthermore, it has been shown that these simple and inexpensive designs, without significant modifications to the system, can achieve high thermal performance without unnecessary expensive components.Öğe Environmental and economic assessment of a low energy consumption household refrigerator(Elsevier - Division Reed Elsevier India Pvt Ltd, 2020) Gurel, Ali Etem; Agbulut, Umit; Ergun, Alper; Ceylan, IlhanEnergy consumption is the biggest obstacle in the economic growth of a country. In recent years, Turkey has imported around at the rate of three-quarters of its total energy demand. Upon the past 10-years running, Turkey paid nearly half a trillion dollars for its total energy bill. The big share of energy consumption has emerged from buildings. Therefore, energy savings have great importance, particularly in the buildings. A refrigerator is responsible for the most dominant electrical energy consumption rate with 32% in a house. Therefore, this paper proposes a novel household refrigerator design for reducing energy consumption. In the proposed design, the necessary air for the cooling process will be provided from outdoor ambient in appropriate weather condition. The compressor work will, thus, be decreased via this way, and contribute to a reduction in energy consumption. The results indicated that this system in 63 provinces can be effectively used between 1 and 4 months and help to reduce 36 million $ in Turkish electric energy bill with the use of only 1 year period. Additionally, a reduction of approximately 850,000 tons of CO2 annually in Turkey can be achieved by applying the proposed design in this study. Hereby, Turkey can contribute not only to be sustained economic growth but also to reduce harmful gas emissions arising from electricity generation methods in the country. (C) 2019 Karabuk University. Publishing services by Elsevier B.V.Öğe Estimation of global solar radiation on horizontal surface using meteorological data(Sila Science, 2012) Gurel, Ali Etem; Ergun, AlperIn the present study, the methods of Artificial Neural Networks (ANN) and Regression Analysis were used in estimating monthly average daily global solar radiation arriving on horizontal surface in Rize with the help of meteorological and geographic data like monthly average daily extraterrestrial radiation, monthly average daily hours of bright sunshine, day length, relative humidity, wind speed, temperature and declination angle. Mean bias error (MBE), root mean square error (RMSE) and t-statistic methods were used to evaluate performance of the estimation. It was seen at the end of the study that the equation obtained through multi-regression analysis method yielded better performance than that of obtained through ANN method.
