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Öğe 4E analysis of an underfloor heating system integrated to the geothermal heat pump for greenhouse heating(Scientific And Technological Research Council Turkey, 2022) Ünal, Fatih; Akan, Ahmet Erhan; Demir, Bünyamin; Yaman, KaanIn this study, 4E (energy, exergy, exergoeconomic, and exergoenvironmental) analysis of an underfloor heating system integrated with the geothermal heat pump of a greenhouse with a usage area of 90 m(2) has been made. When the results of the 4E analysis applied to the system and its elements were examined, the energy efficiency of the heating system in the winter months has been determined to be 77.85% and the exergy efficiency 30.61%. According to the results of exergoeconomic analysis, the levelized energy cost of the system has been determined as 0.894 $/h, the unit exergy cost as 0.826 $/h, and the exergoeconomic factor value as 51.12%. According to the results of the exergoenvironmental analysis, the part-based environmental impact of the system was 0.0910 mPts/s, the environmental impact value due to exergy was 0.1823 mPts/s, and the exergoenvironmental factor value was 37.77%. In addition, the equivalent CO2 emission value that will occur if the heating requirement of the greenhouse is met with a natural gas boiler instead of a geothermal heat pump was investigated and a comparison was made between the two systems. Accordingly, it has been determined that the emission of 909.75 kg equivalent carbon dioxide to the environment will be prevented in the 4-month period, which is considered the heating season, by using the heat pump. As a result, the examined heating system has been evaluated as the effective system for heating the greenhouse, reducing energy consumption, and reducing emissions that cause environmental pollution.Öğe AN APPLICATION TO ERROR AND UNCERTAINTY ANALYSIS IN INDUSTRIAL TYPE DRYER EXPERIMENTS(2021) Ünal, Fatih; Akan, Ahmet ErhanIn this study, information is given about the driers commonly used in the industry and the experimental errors anduncertainties that will be encountered in the experiments using these driers are tried to be explained by using the dataobtained from the experiments carried out in an 8 chambers hot oil heated stenter, which is a conveyor type convectiondryer. The fabric used in the experiments is the Thessaloniki type fabric, containing 67% cotton and 37% polyester. Theexperiments were carried out at a drying air temperature of 160 ºC and a fabric advance rate of 23 m/h (0.383 m/s). Thus,the example of error analysis in such experimental studies is provided and criteria that may cause an error for drying systemsare discussed. As a result of the uncertainty analysis, the largest uncertainty in the system occurred in temperaturemeasurements at ±0.367 - ±0.568 ºC values and the error rate for the whole system was found to be 4.08%. In terms ofconducting the experiments in real production conditions and the materials and methods used in the experiments, this studyis thought to will be help researchers that working on drying systems in their experimental studies.Öğe Analysis of the Heat Pump Performance of Different Refrigerants in a Building with Determined Heating Load According to Ts 825(2020) Akan, Ahmet ErhanIn this study, the performance of a geothermal heat pump used in heating mode for a house whose heating energy need is determined according to the Turkish thermal insulation standard TS 825, with different refrigerants has been theoretically analyzed. Accordingly, the annual heating energy need was calculated by taking the building components of the house into consideration, and it was determined that the heat pump condenser to meet this need should have a capacity of 15 kW. In addition, 7 different refrigerants with zero ozone depletion potential (ODP) in the heat pump system were annalized at variable evaporator temperatures and the performance of the geothermal heat pump was investigated. In the study, thermodynamic analysis was applied to the system by using Hydrochlorofluorocarbons (HFC) refrigerant types R 134a, R 143a, R 404A, R 407A, R 407C, R 410A and R 507A refrigerants for the determined operating conditions of the geothermal heat pump. Solway Solkane 8.0 calculation program was used for analysis. As a result of the analysis, it has been determined that the lowest operating loads and the highest heating effect coefficient values for the same operating conditions will be obtained from the system using R 134a, R407A, R 407C refrigerants, respectively. Moreover it was determined that the refrigerant with the highest pressure ratio value was R 134a.Öğe Assessment of CO2Emissions Reduction Based on Different Insulation Materials in Residential Buildings: Example from Turkey(IOP Publishing Ltd, 2021) Akan, Aytaç Perihan; Akan, Ahmet ErhanIn this study, the reduction of CO2 emissions caused by energy savings due to thermal insulation materials applied to the exterior of buildings was investigated. The study includes the evaluation of four different insulation materials including XPS, EPS, PUR and Rock Wool in terms of the reduction potential of CO2 emissions for all city centers in Turkey. Moreover, the optimum insulation thicknesses of the buildings that have both heating and cooling needs were determined for these insulation materials by means of Life Cycle Cost Analysis. The annual energy needs per unit area of the external walls of the buildings, which are insulated according to their optimum insulation thickness were determined and correspondingly the amount of fuel needed to meet this energy was calculated. In the study, CO2 emission values released from buildings to atmosphere were compared in terms of fuel amounts obtained from total energy demands during heating supplied from natural gas and cooling supplied from electricity of the residential buildings insulated with diverse insulation materials. Consequently, when CO2 reduction potentials of the buildings insulated with materials in the optimum insulation thickness are compared with those of the uninsulated buildings, insulation material providing highest potential in CO2 emission mitigation was to be found as Rock wool. © Published under licence by IOP Publishing Ltd.Öğe Bir Kürk-Süet Üretim Fabrikasının Spesifik Enerji Tüketim Yöntemi İle Enerji Tasarruf Potansiyelinin Araştırılması(2018) Işık, Nuray Olcay; Akan, Ahmet ErhanBu çalışmada bir endüstriyel kürk–süet üretim fabrikasının enerji tasarruf çalışmalarına katkı sağlamak ayrıca enerji yönetimiorganizasyonu tarafından ön enerji tasarrufu etüdü hazırlanabilmesi için, 2016 yılı üretim ve enerji tüketim verilerini kullanarak enerjitaraması gerçekleştirilmiştir. Tarama kürk–süet fabrikasının enerji tüketimi ve üretim verilerinin toplanması, işlenmesi vedeğerlendirilmesi aşamalarını kapsamaktadır. Bu verilere bağlı olarak geliştirilen enerji tüketim bağıntıları yardımı ile hedef enerjitüketimleri hesaplanarak işletmenin enerji tasarruf potansiyeli araştırılmıştır.Öğe Determination and Modeling of Optimum Insulation Thickness for Thermal Insulation of Buildings in All City Centers of Turkey(Springer/Plenum Publishers, 2021) Akan, Ahmet ErhanIn this study, research has been carried out in which the optimum insulation thickness for the thermal insulation of buildings in all city centers of Turkey is determined according to life cycle cost analysis. Besides, the total annual net savings of the buildings in all city centers and the payback period of the insulation were concluded according to the determined optimum insulation thickness. In the calculations, it is assumed that natural gas is used for heating the buildings, and electrical energy is used for cooling. Besides, four different insulation materials (XPS, EPS, PUR, and Rock wool) were selected as the most preferred thermal insulation material in Turkey. The methods applied to determine the buildings' optimum insulation thickness are very time-consuming and dependent on many parameters. Twelve different models have been developed for all city centers that determine the optimum insulation thickness depending on the number of Degree-Days of buildings that need only heating, cooling only, heating and cooling to create a practical approach in determining the optimum insulation thickness. The regression analysis models' suitability using MATLAB R2019a program, with R-2 values being the main criterion, SEE (Standard error estimate), and RMSE (Root mean square error) values are considered. Accordingly, when the similarity between the developed models and optimal insulation thicknesses obtained from theoretical calculations was examined, it was determined that R-2 values were between 0.9683 and 0.9997. It is predicted that this study will provide a practical solution for researchers and designers working on this subject.Öğe Determination of Drying Behaviour in Industrial Type Convectional Dryer and Mathematical Modelling(Vinca Inst Nuclear Sci, 2020) Akan, Ahmet Erhan; Özkan, Derya BurcuIn this study, the performance of a stenter (ram machine) that enables the drying of textile products with hot air is theoretically modelled with a diffusion model derived from Fick's second law. The experimental study was conducted in a 10 chamber stenter with three different drying temperatures (110-130-150 degrees C) and three different fabric speeds (10-20-30 m per minute.) by using a fabric consisting of 95% cotton + 5% lycra. The drying behaviour of the dryer was determined by utilizing the data obtained from the studies. With the help of the utilized model, the values of diffusion coefficients and activation energies were obtained, the conformity of data between the model and the experimental studies were compared by using regression analysis, it was observed that the R-2 value varied between 0.9812 and 0.9961.Öğe Determination of Tekirda (Turkey) wind energy potential and evaluation of selected wind turbines in terms of techno-economic and environmental aspects(Aip Publishing, 2021) Akan, Aytaç Perihan; Akan, Ahmet ErhanIn this study, the wind energy potential of Tekirda was investigated obtaining the wind data from meteorology stations located in nine districts of the province and recorded hourly at 10 m altitude between the years of 2014 and 2018. Moreover, monthly average wind and Weibull and Rayleigh probability distributions, as well as hourly wind speeds, were analyzed for each district. Furthermore, monthly dominant wind directions and the ratio of dominant winds to all wind blowing numbers were determined for each district and wind speeds and wind power densities by month were compared. In addition to determination of wind energy potential, four different types of wind turbines which can be installed in the examined regions were assessed in terms of techno-economic and environmental aspects by using RETScreen Expert software. Capacity factors of selected wind turbines, initial installation costs, annual savings incomes, and annual energy amounts were determined by district. The gross greenhouse gas emission amounts that can be prevented from being released into the environment have been determined via the usage of wind turbine. Finally, the most suitable wind turbines for the districts were determined through financial sustainability analysis. Correspondingly, it has been determined that if the Enercon E2-82 wind turbine is installed in the Marmara Erelisi district, optimal results will be obtained. It is thought that this study will contribute to the development of the wind energy potential and planning of the wind power plants in the regions showing the similar characteristics with the examined one with regard to wind energy. Published under an exclusive license by AIP Publishing.Öğe EDİRNE İKLİM ŞARTLARINDA ÇEVRE SICAKLIĞI VE RÜZGAR HIZININ POLİKRİSTAL FOTOVOLTAİK PANEL ÇIKIŞ GÜCÜNE ETKİLERİNİN İNCELENMESİ(2022) Akan, Ahmet Erhan; Akal, DinçerBu çalışmada, Edirne ilinde kurulu bir polikristal fotovoltaik panelli güneş enerjisi sisteminin performansının çevre sıcaklığı ve rüzgar hızı ile değişimi araştırılarak, bu unsurların fotovoltaik sistem performansı üzerine etkileri incelenmiştir. Bu amaçla 1 Ağustos – 30 Eylül 2020 tarihleri arasında yapılan deneyde kullanılan sensörler aracılığı ile ölçülen iklimsel veriler ile panel çıkış gücü ve akım değerleri, sisteme bağlı bulunan Arduino Mega mikro işlemci karttaki yazılım vasıtasıyla hafıza kartına (SD kart) 10 dakika aralıklarla aktarılması sonucu elde edilmiştir. Çalışmadan elde edilen bulgulara göre, ortam sıcaklığındaki artışın fotovoltaik panellerin sıcaklığını arttırdığı, güneş radyasyonu miktarının ise üretilen elektriği doğru oranda etkilediği tespit edilmiştir. Fotovoltaik panel performansına rüzgâr hızının etkileri değerlendirildiğinde ise, rüzgâr hızının artan değerlerinde panel sıcaklıklarının düştüğü tespit edilmiş, fakat incelenen bölge için belirlenen nominal rüzgar hızlarının sayısının çok düşük değerlerde olduğu bu sebeple panellerin soğutulmasında rüzgarın direkt soğutucu olarak kullanılmasının yetersiz olacağı, panellerin soğutulması için yardımcı soğutma sistemlerinin kullanılması durumunda panellerin çıkış gücünün artacağı sonucuna varılmıştır.Öğe Evaluation of feasibility analyses for different hub heights of a wind turbine(Erol Kurt, 2022) Akan, Ahmet Erhan; Akan, A.P.In this study, techno-economic and environmental feasibility analyses of a wind turbine for different hub connection heights were investigated using RETScreen Expert energy analysis program. Çerkezköy district of Tekirda? province was chosen as the region in which the wind turbines will be constructed. According to the analysis of hourly wind speed data recorded by a meteorology station established in Çerkezköy, it can be easily said that the annual average wind speed for 10 m altitude is 5.305 m/s and the directions of the prevailing winds are between NE (45o) and ENE (67.5o). The model of the wind turbine chosen in the present study is the Sinovel 1500/77, and techno-economic and environmental evaluations were made for the hub connection heights of 65, 80 and 100 m. In accordance with the study results, when the payback period is evaluated in terms of energy production cost and greenhouse gas reduction potential, the wind turbine with 100 m hub connection height exhibits better results than others with 65 and 80 m. It is thought that this study will guide selecting a suitable hub height for wind power plants and wind turbines that are planned to be established in Çerkezköy, one of the largest industrial regions of Turkey to obtain cost-effective and environment-friendly conditions. © 2022.Öğe Experimental examination and theoretical modeling of drying behavior in the ram machine(Taylor & Francis Inc, 2020) Akan, Ahmet Erhan; Özkan, Derya BurcuIn this study, drying behavior of a ram machine, basically used for drying of textile products with hot air, was experimentally examined and the drying behavior was theoretically modeled by the first order kinetic model derived from Fick's second law. The experimental study was carried out under real conditions in a 10-chamber ram machine. The experiments were carried out at three different drying air temperatures (110-130-150 degrees C) and three different fabrics feed rates (0.167-0.333-0.500 m/s) by using 95% cotton + 5% lycra content fabric. By utilizing the data obtained from the experiments, the evaporation amount, the non-dimensional humidity ratios, the heat and mass transfer coefficients and energy efficiency analysis occurring in each cabin were calculated. It was observed that the R-2 values varied from 0.9945 to 0.9994 by comparing the model and experimental data with the help of regression analysis. According to the values obtained from the experimental conditions, when the drying air temperature was increased from 110 degrees C to 130 degrees C, the heat convection coefficient increased by about 15-23% while the energy efficiency decreased by about 4%. In the same way, when the drying air temperature was increased from 130 degrees C to 150 degrees C, the heat convection coefficient increased by about 20-30% while the energy efficiency decreased by about 5%. In addition, it was concluded that the use of the first order kinetic model as a drying model in the ram machine was considerably suitable. With the presented results, both academic researchers and industrial researchers will be able to find explanatory ideas on the drying behavior of dried fabrics in the ram machines.Öğe INVESTIGATION OF EFFICIENCY OF R717 REFRIGERANT SINGLE STAGE COOLING SYSTEM AND R717/R744 REFRIGERANT CASCADE COOLING SYSTEM(2021) Ünal, Fatih; Özkan, Derya; Akan, Ahmet ErhanThis study is an adaptation of ammonia cascade cooling systems using carbon dioxide on ice cream production machinesand includes thermodynamic analysis of R717/R744 cascade refrigeration system with R717 refrigerant single-stagerefrigeration system and investigation of its efficiency. As a result of the analyses, the COP value of the single-stage systemwas 3.67, the Carnot efficiency was 0.57, the second law efficiency was 0.19 and the power required to operate thecompressor was 27.55 kW. In the cascade cooling system, the COP value was 4.46, the Carnot efficiency 0.59 and thecompressor power 22.7 kW in the high-temperature part, while the COP value was measured as 14.65, the Carnot efficiency0.58 and the compressor power 6.4 kW in the low-temperature part. For the whole cascade system, the COP 3.24 and thesecond law efficiency were found to be 0.43. When the results were compared, it was concluded that although the COPvalue of the cascade cooling system was 0.43 points lower than the single-stage ammonia system, when our country'sclimate conditions and the thermophysical properties carbon dioxide gas were considered together, one of the most suitabledesigns was the cascade cooling system.Öğe Investigation of Energy Saving Potential in Buildings Using Novel Developed Lightweight Concrete(Springer/Plenum Publishers, 2020) Akan, Ahmet Erhan; Ünal, Fatih; Koçyiğit, FatihIn this study, three different composite materials were produced from mixtures of natural and waste materials in different proportions. The produced composites were used to determine the insulation thickness of exterior walls of buildings located in 12 provinces selected from the four different climate zones of Turkey. The selection of provinces was made according to Turkish standard TS 825. The produced materials are thermal insulation elements that can be used instead of construction elements, such as brick, on the exterior walls of the buildings. In this study, only the heating of the buildings was considered and the number of heating degree days of the provinces was taken into account to determine the insulation thickness. The life cycle cost analysis method was used to determine the optimum insulation thickness. It was determined that the optimum insulation thickness values calculated for four different fuel types for the selected provinces varied between 0.170 m and 1.401 m. The annual energy requirement for the unit surface area of the exterior walls of the insulated buildings was determined to be 11,213-965,715 kJ center dot m(-2) per year. Moreover, it was determined that the insulation costs ranged between $ 22,841 m(-2) and $ 114,841 m(-2), and the payback period ranged from approximately 2.5 to 6.5 years. It was concluded that using these new types of materials in the determined regions were advantageous in terms of thermal insulation, fire resistance, mechanical properties, production costs, extra labor costs, and optimum insulation thickness.Öğe Iplik kurutma prosesinin enerji ve ekserji analizi(Namık Kemal Üniversitesi, 2012) Akan, Ahmet ErhanGünümüzde sürekli artan enerji ihtiyaçları nedeniyle mevcut enerji kaynaklarının daha verimli bir şekilde kullanılması kaçınılmaz bir hal almıştır. Bu nedenle mühendislik sistemlerinin verimlilikleri konusunda yapılan araştırmalar da oldukça önem taşımaktadır. Bu çalışmada basınçlı sıcak hava ile farklı kurutma şartları altında kurutma işlemine tabi tutulan yün iplik bobinleri için enerji ve ekserji analizleri yapılarak enerji ve ekserji verimliliği bakımından optimum kurutma koşulu belirlenmiştir. Kurutma işlemi 80o C, 90o C ve 100o C olmak üzere üç farklı sıcaklık ile 1bar, 2bar ve 3bar olmak üzere üç farklı basınç şartları altında yapılmıştır. Elde edilen sonuçlar, hem enerji hem de ekserji verim değerlerinin en yüksek olduğu kurutma koşulunun 1bar basınç, 100o C sıcaklıkta olduğunu göstermektedir.Öğe Modeling of CO2 emissions via optimum insulation thickness of residential buildings(Springer, 2021) Akan, Aytaç Perihan; Akan, Ahmet ErhanThe present study aims to determine and model CO2 emissions based on the energy savings through the thermal insulation applied to the external walls of the buildings for eighty-one different zones using four diverse thermal insulation materials. Depending on the by life cycle cost analysis (LCCA) and the number of degree-days, optimum insulation thicknesses were determined in the present study, in which the heating and cooling needs of the buildings were considered separately. The net savings associated with insulated buildings were also calculated, including the optimum insulation thickness and the payback period for the insulation applied. In buildings with thermal insulation, it has been determined that CO2 emissions will be reduced by approximately 66-76% during the heating season and by 46-69% during the cooling season. Moreover, the amount of CO2 emissions released into the atmosphere from uninsulated and insulated buildings was modeled with ten polynomial-type functions derived from the MATLAB R2019a program. The model results controlled by regression analyses revealed statistical suitability. These models demonstrate a more advantageous approach than prior studies for determining the annual total CO2 emissions per unit area of the exterior walls of buildings. This study is intended to assist housing authorities and designers in making informed decisions about energy savings in buildings. [GRAPHICS] .Öğe Ram makinesinde kurutma prosesinin enerji verimliliği analizi(2019) Akan, Ahmet Erhan; Özkan, Derya BurcuTekstil sektöründe ram makineleri, kumaşların makine içerisinde enine bir şekilde paletler tarafındantutturulduğu, bir çift yürüyen zincirle kumaşın hareketinin sağlandığı ve bu esnada kumaşa sıcak havanıngönderildiği kurutma makineleridir. Bu çalışmada, 10 kabinli bir ram makinesinin kurutma prosesinde, enerjiverimliliğini arttırmak hedeflenerek, gerçek üretim şartlarında deneysel çalışma yapılmıştır. Deneyler üçfarklı kurutma havası sıcaklığında (110 – 130 – 150 o C ) ve 10 m/d kumaş ilerleme hızında, %95 pamuk +%5likra içerikli kumaş kullanılarak gerçekleştirilmiştir. Deneylerden elde edilen verilerden yararlanılarak, herkabinde gerçekleşen ısı-kütle transfer katsayıları, buharlaşma miktarı, taşınım yolu ile kumaşa aktarılan enerjihesaplanmıştır. Yapılan çalışmada; kurutma havası sıcaklığı 110 o C’den 130 o C’ye çıkarıldığında, ısı transferkatsayısı yaklaşık %6 artarken, enerji veriminde %4 azalma, kurutma havası sıcaklığı 130 o C’den 150 o C’yeçıkarıldığında, ısı transfer katsayısı yaklaşık %26 artarken enerji veriminin %5 azaldığı sonuçlarınaulaşılmıştır.Öğe Simulation and thermodynamic analysis of a hot-air textile drying process(Taylor & Francis Ltd, 2015) Akyol, Uğur; Akan, Ahmet Erhan; Durak, AhmetThis paper is concerned with the simulation of drying behavior of wool yarn bobbins and also determination of the optimum operating conditions by using thermodynamic analysis. Firstly, experimental drying behavior of wool yarn bobbins was determined on a hot-air bobbin dryer. Empirical and semi-empirical mathematical models available in the literature were fitted to the experimental data. Then, a multi-layer feed forward neural network structure was used to predict drying behavior of wool bobbins. Afterwards, the first and second law analyses were performed to determine the optimum drying conditions. It was concluded that both the Two Term and Verma et al. models and also the artificial neural network model successfully simulates the drying process. Furthermore, according to the energy and exergy analyses' results, P-eff = 1 bar and T = 100 degrees C were found to be the optimum operating conditions in convective drying process of wool yarn bobbins.Öğe Thin-Layer Drying Modeling in the Hot Oil-Heated Stenter(Springer/Plenum Publishers, 2020) Akan, Ahmet Erhan; Ünal, FatihAlthough the drying processes have an important place in the textile industry in terms of drying or various textile finishing applications, they are considered as an expensive process in terms of energy and time consumed. Therefore, it is of great importance to simulate with mathematical models the drying behavior of a stenter (ram machine), one of the most preferred convection dryers in the textile industry. For this purpose, in this study, modeling was attempted of the drying behavior of 67 % Cotton + 33 % Polyester containing Thessaloniki knit fabrics, using experimental data obtained from drying processes performed in 9 different drying operations in a 10-chamber hot oil-heated stenter and 12 different empirical and semi-empirical thin-layer models that are frequently used in the literature. R(2)values from regression analysis were evaluated as the primary factor in the model fit selection. According to the results obtained, it was understood that the Diffusion Approach model with R(2)values ranging from 0.9991 to 0.9999, Two Term Model with R(2)values ranging from 0.9995 to 0.9999, and the Modified Henderson and Pabis model with R(2)values ranging from 0.9995 to 0.9999 gave the most appropriate results upon simulating drying behavior. In this regard, this study, which contains explanatory information on the drying behavior in a stenter, is thought to be useful to researchers.
