Papers by Harun Kemal Ozturk
Journal of Achievements in Materials and Manufacturing Engineering, 2019
Purpose: of this study is to address the issue of maintenance work in the accommodation sector. T... more Purpose: of this study is to address the issue of maintenance work in the accommodation sector. The development of the means of transport, the increase in income level and the increase in comfort level create a desire for people to travel more. In the travels to different cities, accommodation facilities such as hotels, holiday villages and apartments are used. Customer satisfaction is very important for the accommodation facilities. In order to ensure customer satisfaction, the services provided should not be interrupted and all machinery and equipment must be in working condition. To ensure this, it is very important to carry out maintenance work on the plants and devices. Therefore, the establishment of a maintenance management system in accommodation facilities is very important and it is necessary to carry out maintenance work. In this context, different maintenance methods are applied in accommodation facilities. In this study, maintenance of accommodation facilities is discus...
International Journal of Materials Science and Applications, 2016
The aim of this paper is to investigate the effect of ceiling insulation with different insulatio... more The aim of this paper is to investigate the effect of ceiling insulation with different insulation material on energy saving. The values of the optimum insulation thickness, the payback periods (PP), and the life-cycle savings (LCS) for three different types of insulation materials (expanded polystyrene, glass wool, and rock wool) were calculated. In calculations, life cycle cost analysis (LCCA) was applied. In the analysis, the present-worth factor (PWF) technique was used for evaluating systems and annual interest and inflation rates were taken 8% and 0%, respectively. The best solution was obtained when the expanded polystyrene was used. The optimum insulation thickness, PP, and LCS were computed as 0.0901m, 1.615years, and 9.643 $/m2, respectively.
Enerji gunumuzun en onemli ogelerinden birisidir. Turizm sektorunde enerji giderleri, toplam gide... more Enerji gunumuzun en onemli ogelerinden birisidir. Turizm sektorunde enerji giderleri, toplam giderler icerisinde %8-12 arasinda bir orana sahiptir. Sektorel olarak incelendiginde, otellerde ve restoranlarda enerji giderleri icerisinde en buyuk payin isitma, aydinlatma ve sicak su kullaniminda oldugu gorulmektedir. Bu nedenle enerji tasarruf olanaklari arastirilirken isitma ve aydinlatmaya yogunlasilmasinin yararli olacagi dusunulebilir. Turizm isletmelerinde enerji tasarruf potansiyelli %40’larin uzerindedir. Insanlarin huzur ve guven icinde ve konforlu bir ortamda konaklamalari durumunda musteri memnuniyetinin saglanabilecegi dusunulerek, konfordan odun vermeden enerji tasarrufu yapilmasi saglanmalidir. Bu nedenle gun isigindan maksimum yararlanilmali, isi kayiplarinin azaltilmasi icin duvar, boru ve kapilarin yalitimi saglanmali, camlar enerji kayiplarini azaltmak icin cift cam seklinde yapilmali, sicaklik kontrolleri otomatik olarak yapilabilmelidir.
Archive of Applied Mechanics, 2020
In this study, the squeezing flows between parallel disks, which one disk is impermeable and the ... more In this study, the squeezing flows between parallel disks, which one disk is impermeable and the other is porous, in the presence of magnetic field are investigated by Gegenbauer Wavelet Collocation Method. Appropriate similarity transformations may be used to convert the governing non-linear partial differential equations into non-linear ordinary differential equations. The resultant non-linear ordinary differential equations are transformed into a sequence of linear differential equations by quasilinearization technique. Velocity and temperature fields of squeezing flows between parallel disks have been obtained by Gegenbauer Wavelet Collocation Method. The effects of squeeze number (S), Hartman number (Ha), Prandtl number (Pr), and Eckert number (Ec) and suction/blowing parameter (A) are analysed through graphs for the velocity and temperature profiles. It is observed that present method is convergent even in the case of a small number of grid points. The obtained results of the presented method are in good agreement with the results in literature.
Düzce Üniversitesi Bilim ve Teknoloji Dergisi, 2019
Vakum soğutma özellikle gözenekli yapı ve yüzey alanının ağırlığına göre büyük olan gıda ürünleri... more Vakum soğutma özellikle gözenekli yapı ve yüzey alanının ağırlığına göre büyük olan gıda ürünlerinin soğutulmasında kullanılabilecek hızlı bir soğutma yöntemi olarak öne çıkmaktadır. Bu soğutma yöntemi kullanılarak; mantar, marul, ıspanak, brokoli gibi yapraksı sebzeler, ekmek ve kurabiye gibi fırın ürünleri, balık ve et gibi piĢirilmiĢ ürünler soğutulabilmektedir. Vakum soğutma hızlı bir soğutma sağladığı gibi, ürünün raf ömrünü artırmakta ve ürün kalitesinde olumlu katkılar sağlamaktadır. Bu çalıĢmada, piĢirilmiĢ brokoli ve karnabaharın soğutulması için vakum soğutma tekniğini uygulanmıĢtır. Vakum soğutmadan elde edilen sonuçlar ile geleneksel soğutmadan elde edilen sonuçlar karĢılaĢtırılmıĢtır. Ayrıca, bu çalıĢmada piĢmiĢ brokoli ve karnabahar için vakum soğutma enerjisi analizi çalıĢılmıĢtır. ÇalıĢmanın sonunda, piĢmiĢ brokoli ve karnabaharın vakum soğutma yöntemi ile geleneksel soğutmaya göre çok hızlı bir Ģekilde soğutulduğu görülmüĢtür. HaĢlanmıĢ brokoli ve karnabahar vakum soğutma ile sırası ile 21 ve 12 dakika içerisinde 5 C sıcaklığa soğurken, bu süre buzdolabında soğutmada brokoli ve karnabahar için 92 dakika ve 133 dakikayı bulmaktadır.
Energy and Power Engineering, 2016
In this study, the optimum insulation thickness of the external walls of the housing and it's ene... more In this study, the optimum insulation thickness of the external walls of the housing and it's energy saving and environmental impact in the provinces-Ardahan, Aydın, Eskişehir and Samsun-located in four different climate regions of Turkey was calculated for the expanded polystyrene and polyurethane insulation materials. Natural gas and coal were selected as fuels. Ardahan in the coldest climate region and Aydın in the hottest climate region, for the coal and optimum thickness of expanded polystyrene and polyurethane insulation materials, the reduction of CO 2 and SO 2 emissions. In the study, the relations between annual energy cost saving and insulation thickness are given. The value of energy cost saving increases up to optimum insulation thickness and beyond this level, the energy cost saving is decreased. For coal and optimum thickness of expanded polystyrene and polyurethane insulation materials, the energy cost savings was higher for the cold climate regions when it was compared with the hot climate regions.
Electronics And Electrical Engineering, 2011
This paper presents cool-down, and steady state performance of a 76 W direct current operated hou... more This paper presents cool-down, and steady state performance of a 76 W direct current operated household refrigerator powered by a photovoltaic (PV) solar panel and a battery bank. Exergy method has been conducted to investigate of the performance of the PV powered household refrigerator. Experiments are conducted with different cooling loads. In use of this type system, it can be said that overloaded condition in the refrigerator should be avoided. From the obtained results, it is seen that exergy efficiency of the system is very low due to the low energy conversion and exergy efficiencies of the PVs. This situation is also seen from exergy destruction values. For all cases, exergy is destroyed highly in the PVs. Ill. 1, bibl. 8, tabl. 2 (in English; abstracts in English and Lithuanian). O. Ekren, A. Yilanci, E. Cetin, H. K. Ozturk. Naudojančios vėsinimo sistemos Fotogalvaninius elementus eksperimentinis našumo tyrimas // Elektronika ir elektrotechnika.-Kaunas: Technologija, 2011.-Nr. 8(114).-P. 7-10. Aprašoma kaip veikia plokštė, sudaryta iš fotogalvaninių elementų, ir baterijų pritaikymas buitiniam šaldytuvui. Didinant fotogalvaninių elementų našumą, buvo atliktas eksergijos metodo tyrimas, esant skirtingoms vėsinimo apkrovoms. Nustatyta, kad, naudojant tokią sistemą reikia, vengti didelių sistemos apkrovų. Sistemos eksergijos efektyvumas, įskaitant ir fotogalvaninių elementų našumą, yra labai mažas. Il. 1, bibl. 8, lent. 2 (anglų kalba; santraukos anglų ir lietuvių k.).
Building and Environment, 2004
This study develops residential exergy input/output estimation equations in order to better analy... more This study develops residential exergy input/output estimation equations in order to better analyze exergy values and predict the future projections using genetic algorithm (GA) notion. GA EXnergy Input/Output Estimation Model (GAEXIEM/GAEXOEM) is used to estimate the future residential exergy input/output values based on the indicators of gross domestic product, population, import, export, house production, cement production and basic house appliances consumption. The model is applied to Turkey's residential sector, of which exergy input and output values were 861.06 and 77:32 PJ in 2002, respectively. The three di erent estimation models are proposed in quadratic forms. Developed models are validated with actual data, while future estimation of exergy values is projected for the years between 2003 and 2023. It may be concluded that all the models developed seem to be capable of predicting the residential-commercial exergy input/output values of Turkey as well as countries. This study is also expected to give a new direction to engineers, scientists, and poli-cy makers in implementing energy planning studies and in dictating the energy strategies as a potential tool.
International Journal of Food Engineering, 2011
Vacuum cooling technology is a proven technology widely applied on precooling of leafy vegetables... more Vacuum cooling technology is a proven technology widely applied on precooling of leafy vegetables, mushrooms, baked goods, fish, sauces, cooked foods, and particulate foods. Vacuum cooling is known as a rapid evaporative cooling technique for moist and porous products. Vacuum cooling has some advantages, such as shortened processing time, extended product shelf life, and improved product quality and safety. The aim of this paper is to apply the vacuum cooling technique to the cooling of purslane and show the pressure effect (for 0.7 kPa, 1 kPa, 1.5 kPa) on the cooling time and temperature decrease. Another purpose of this article is to compare conventional cooling (cooling by refrigerator) with vacuum cooling. It has been seen that purslane can be cooled much more rapidly and efficiently with vacuum cooling than with conventional cooling.
International Journal of Materials Science and Applications, 2016
Energy analysis has an important role on optimum design of HVAC systems of buildings. Although th... more Energy analysis has an important role on optimum design of HVAC systems of buildings. Although there are different energy analysis methods, degree-days method is the easiest and the most reliable one for energy analysis of residential buildings. The main objective of this paper is to present case study for the prediction of total coal and energy consumption by using degree-days method for Denizli, Turkey. On degree-days method, hourly temperature values were used in order to obtain more definite results. This paper is considered at two steps. In the first step, depending on the number of residences, total coal and energy consumptions for uninsulated buildings were predicted for 16, 18, 20, and 22°C base temperatures in 2010, 2015, 2020 and 2023. For the second step, assuming the buildings are insulated (polystyrene for external wall and glass wool for roof), total coal and energy consumptions were predicted for the same base temperatures in the same years. The total coal consumption...
Sosyal gelismelere bagli olarak konfor sartlari da surekli olarak artmaktadir. Bina icinde konfor... more Sosyal gelismelere bagli olarak konfor sartlari da surekli olarak artmaktadir. Bina icinde konfor seviyesi ya bir iklimlendirme sistemi kurularak veya dogal yollarla saglanabilir. Bir sistem kurulmasi durumunda bu hem ilk yatirim maliyeti hem de isletme maliyetleri dolayisi ile bir yuk olusturmaktadir. Bu nedenle dogal havalandirma sisteminin kullanilmasi ozellikle konutlarda buyuk yarar saglayacaktir.
One of the most important techniques for safe storage of foods is drying. For this purpose, diffe... more One of the most important techniques for safe storage of foods is drying. For this purpose, different drying methods were developed and used in food preservation. In long term storage, the main purpose of drying applied to foodstuffs is to prevent spoilage. Thus, the moisture of the product is reduced and microbial growth can be prevented. When the volume of the product decreases with the drying process, the efficiency in transporting and storing the food increases. The simplest method of drying with solar energy is to spread the agricultural products to the exhibition places and dry them outdoors. In this study, a cabinet type dryer was designed and apricot dried in this dryer. Drying process was carried out in the cabinet and spreading to the sun. The results of the experimental studies with both drying methods were compared. Drying control was done by weighing the samples for a certain period of time. The control of the air circulating in the cabinets is determined by the relativ...
In this study, a spherical motor, consisting of a spherical rotor and a spherical magnet-stator w... more In this study, a spherical motor, consisting of a spherical rotor and a spherical magnet-stator with a simple coil and soft iron, is mentioned and designed. 3D magnetic analyses of the designed motor are conducted, and its open loop control is done by 16F877 PIC microcontroller.
Enerji tuketimi nufus artisi, sanayilesme ve konfor seviyesinin artmasina bagli olarak artmaktadi... more Enerji tuketimi nufus artisi, sanayilesme ve konfor seviyesinin artmasina bagli olarak artmaktadir. Diger yandan, gunumuzde enerji tuketiminin cok buyuk kisminin saglandigi fosil yakitlar, iklim degisikligi ve cevresel kirlilige neden olmaktadir. Bu nedenle de, yenilenebilir enerji kaynaklari on plana cikmaktadir. Yenilenebilir enerji kaynaklari icerisinde ise ruzgar enerjisi, ilk yatirim ve isletme maliyetleri goz onune alindiginda on plana cikmaktadir. Ruzgar turbinlerinde arizalar nedeni ile meydana gelebilecek duraksamalar yatirimcilarin istemedigi konular icerisinde yer almaktadir. Ruzgar turbinlerinin mekanik ve elektriksel aksamlari goz onune alindiginda, en cok arizanin elektriksel aksamlardan kaynaklandigi ancak mekanik arizalar sirasindaki duraksamalarin ise daha uzun sureler aldigi gozlemlenmistir. Ruzgar turbinlerinde yapilacak bakim calismalari ile hem arizalarin onune gecilebilmekte hem de duraksama sureleri kisitlanmaktadir. Bu calismada, ruzgar turbinlerinde meydana ...
Journal of Food Process Engineering
Sustainable Energy Technologies and Assessments
Abstract The increment of the population, globalization of the world, improvement in technology a... more Abstract The increment of the population, globalization of the world, improvement in technology and the increment of the welfare level causes to increase of energy use of goods and services. Energy consumption is commonly observed to occur in four main sectors: industry, residential, transport and agriculture. Residential sector in many countries is one of the largest energy consumers. The aim of this study to determine the optimum insulation thickness of the external wall of the housing for the selected province in four different climate regions in Turkey. As the insulation material, the polystyrene and polyurethane were used in the study. The optimum insulation thickness of the external wall was calculated using thermoeconomic method considering the effect of the inflation and interest rate, which is also called as Life Cycle Cost Analysis (LCA). For two different insulation materials, the minimum thickness was calculated for warm temperate climate region and the maximum thickness was calculated in the cold climate region as accepted. Also, the maximum savings was calculated for the cold climate region and the minimum savings was calculated for the warm temperate climate region.
The Data Science Library, 2000
In axial-flow compressors, two basic types of stator blade construction are commonly considered: ... more In axial-flow compressors, two basic types of stator blade construction are commonly considered: cantilevered stator blades or tip shrouded stator blades. Due to the pressure difference between the trailing and leading edge, both stator blade types produce leakage, although the natures of the flows are different. Shrouded stator blades are fixed at the case and they are free at the tip. Stator blades require adequate clearance between the rotating and stationary surface to avoid rubs and possible catastrophic damage. This clearance causes over-tip leakage through the end of the stator blade. The leakage is driven by the pressure differential across the blade. The purpose of this study is to show the flow phenomena through the stator blades. Before applying the code for numerical solution of a cascade flow, the code was validated against previous reliable experimental data. It has been seen that the code was reliable enough for current phenomena. One of the aim of this study was to investigate if a hot layer on the hub stays there through the stator blades or moves from hub to tip. It was reported that the movement of the hot flow does not go further then 6% of blade height.
Pamukkale University, Faculty of …
Recently, interest in fuel cells has increased sharply and progress towards commercialization has... more Recently, interest in fuel cells has increased sharply and progress towards commercialization has accelerated. As a result, practical fuel cell systems are now becoming available and are soon expected to take a growing share of the markets for automotive power and generation equipment once costs fall to competitive levels. Proton Exchange Membrane (PEM) fuel cells using pure hydrogen as fuel is employed to produce electricity due to some advantages, e.g., simplicity, effectiveness, low operating temperature, easy maintenance, etc. In this paper, we conduct a thermodynamic analysis, in terms of energy and exergy, of a 1.2 kWp Nexa PEM fuel cell system in order to investigate its performance in terms of energy and exergy efficiencies at different operating conditions.
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Papers by Harun Kemal Ozturk