Garp linyit işletmelerinde kullanılan çekme kepçeli yerkazarların güvenirlik analizleri
Reliability analysis of dragline systems used in G.L.İ
Yazar: CAN DURU
Danışman: DOÇ. DR. HAKAN TUNÇDEMİR
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Maden Mühendisliği Ana Bilim Dalı / Maden Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: Maden Mühendisliği ve Madencilik = Mining Engineering and Mining ; İstatistik = Statistics

Özet:
İnsanlık tarihinin en eski mesleklerinden olan madencilik geçmişten günümüze büyük değişikliklere uğramıştır. Antik çağlardan sanayi devrimine kadar olan süreçte harcanan emek insan gücü tarafından sağlanırken sanayi devriminden sonra insan gücü yerini makineleşmeye devretmiştir. Madencilik faaliyetlerinin üretim sürekliliği, sürdürülebilir bir mekanizasyon planlamasını zorunlu kılmıştır. Günümüzde madencilik faaliyetleri gerçekleştirilirken yüksek kapasiteli, verimliliği yüksek ve uzun süre dayanabilen makineler kullanılmaktadır. 
20. yy. başlarından beri aktif olarak kullanılan çekme kepçeli yerkazarlar yüksek kapasiteleri dolayısı ile arızaları durumunda önemli üretim kayıplarına sebep olmaktadır. Bu durum tesis verimliliği açısından önemli sorunlar çıkarmaktadır. 
Bu çalışma sınırları içerisinde GLİ Tunçbilek İşletmesinde kullanılan MARION 7820 model çekme kepçeli yerkazar ile kullanımı 2015 yılının mayıs ayı itibariyle son bulmuş 2018 başlarında ise hurdaya ayrılmış PAGE 736 model çekme kepçeli yerkazarın duruş ve arıza sürelerinden faydalanılmıştır. Bu süreler kronolojik olarak tasnif edilmiş, devamında ise bu süreler çekme kepçeli yerkazarın alt birimlerine göre sınıflandırılmıştır.
 Sınıflandırma işleminin devamında verilerin bir eğilim gösterip göstermediğini anlayabilmek için eğilim analizine tabii tutulmuştur. Burada elde dilen sonuca paralel olarak uygun dağılım modeli seçilmiştir.
 Bu çalışmada Weibull dağılımı yöntemiyle genel güvenirlik analizi gerçekleştirilmiştir. Böylece çekme kepçeli yerkazar makinalarının ve çekme kepçeli yerkazar ünitelerinin yıllara bağlı güvenirlik değişimleri tespit edilmiştir. 
Bu güvenirlik değişimleri her bir alt ünite için ayrı ayrı hesaplanıp sonunda çekme kepçeli yerkazarların hangi ünitelerinin daha güvenilir olduğu tespit edilmiştir. Tahmin edilen arızalar arası sürenin bulunabilmesi içinde elimizde ki verilerin uygun dağılım göstermesinden dolayısıyla Poisson dağılımından elde edilen denklemler kullanılmıştır. 
Bu denklemlere bağlı olarak çekme kepçeli yerkazarların en son yaptıkları arıza veya duruşlardan sonra bir sonraki arıza ve duruşlarının etkili bir biçimde tahmin edilmesi için gerekli matematiksel hesaplamalar yapılmış ve tahminlerin gerçek veriler ile örtüşmesi durumu gözlemlenmiştir. Bu bağlamda karşılama oranları tespit edilip uygun bir biçimde yorumlanmıştır. Bu tarz nümerik yaklaşımların çalışmaların maden makinelerinin performansı açısından önemi vurgulanmış olup gelecek çalışmalara da kaynak ve dayanak olması esas alınmıştır.

Abstract:
Since the dawn of human civilization, mining has been one of the major and important profession in human history  which has undergone major changes to the present. From the ancient times up to the industrial revolution, human labor was the most important input in the process which was provided by workers themselves. After the industrial revolution manpower was replaced by mechanization. Hence, the continuity of production of mining activities necessitated a sustainable mechanization planning. The yield of a mining activity is directly correlated by accesible of the mining machinery Nowadays, high capacity, high efficiency and highly endured complex machines are used in mining activities. 
Mining operations also have significant cost items and obligatory. The most important of cost is machinery and equipment costs. For this reason, machinery-equipment designs must be examined in terms of performance and in mining operations. Even so the prediction of the failures of a mining machine informs the engineer of the important production downtime and allows him to optimize. Therefore, the 20th century. In the early days, the concept of reliability engineering was invented. 
Reliability engineering explains how long a machine can be operated without malfunction and helps to be aware of possible future failures with the help of statistical approaches. These analyses were also used to undermine the vital factors which mostly affect the draglines reliability. Statistically, reliability was defined as the general consistency of a unit of measurement. Reliability is a quantitative concept. Reliability can also be defined as the average number of failures (failure rate) at a given time. Assessment of reliability is not only an indicator of the analysis of typical systems under repeated care The determination of failure rate plays a very important role in carrying out the reliability analysis. The main objectives of reliability engineering are to apply engineering knowledge and expertise techniques to prevent or reduce the frequency of failures; and to apply methods to analyze reliability data. Reliability can be defined as a machine will perform a desired function in some way without downtime or failure for a certain period of time under certain conditions. The main purpose of reliability management is to predict unexpected system downtime in order to reduce maintenance costs in the mining sector in general. 
In mathematical sense, reliability is defined by the function, which provides the possibility that there is no failiure for a given time interval. The reliability analysis in the classification of the analyzed statistical methods is based on the observed failure data and appropriate statistical techniques. The proper modeling and interpretation of the relationships between inputs are the most important activities in the evaluation and development of the reproducibility of the system performance. When the reliability analysis performed, the classification of the analyzed statistical methods is based on the observed failure data and appropriate statistical techniques. Proper modeling and interpretation of the relationships between inputs are the most important activities in evaluating and improving the reproducibility of system performance. The analysis were examined  utilizing the downtime datas supported by the GLI which the coal mine was settled in Tunçbilek/Kütahya.
Dragline excavators, which have been actively used since the beginning of the twentieth century, one of the significant mechanical systems in terms of its high capacity and performance. Therefore, downtimes cause significant production losses. That presents major problems according to mechanical efficiency. The reliability analysis implements failure probability distributions for the draglines' components to determine failure behavior. 
In this study, after a detailed literature research, with the permission of GLI, a 20-year data collection on the failure data of MARION 7820 and PAGE 736 model draglines were obtained from GLI. Furthermore, obtained data were firstly classified chronologically for two major dragline excavation systems has selected from GLI in terms of their persistence and surplus of their downtime repository. One of the selected dragline is MARION 7820, has been working since 1977 and the another one is PAGE 736 which had worked the years between 1970 and 2015 and wrecked in 2018.
Those draglines failure and downtimes has obtained and  classified according to their  subunits. Following the classification process, firstly a trend analysis was carried out in order to understand whether the data show a trend. The first step in determining the model to be used in the reliability analysis is, of course, whether the data currently used show a trend. Therefore, it should be checked whether the periods between the periodic stops have a tendency. The breakdown and downtime data were firstly chronologically listed and then the distribution to the machinery room, dragging unit, rigging unit, hoisting unit, bucket unit and movement units was determined. Subsequently, reliability analyzes were performed separately for each unit. In addition to these analyzes, future failures are estimated. These times were compared with the actual data and the differences were determined. 
Secondly, the appropriate distribution model was selected parallel to the result obtained. The fact that inter-stop times show a certain trend is an important parameter, especially for estimating the next stop time. MATLAB 2018b program was used to determine the probability distribution of the MARION 7820 model and PAGE 736 model dragline excavator strong correlation of the data sets used. In the study, the scale and shape parameters required for Weibull analysis were first taken into MATLAB 2018b program of the data stored in Microsoft Excel format. Subsequently, the appropriate distribution was selected from the applications section. Shape and scale parameters of the appropriate distribution were determined and transferred to the study and reliability analysis was performed according to these parameters. Futhermore, general reliability analysis was performed by using Weibull Analysis method. Thus, years of dependability changes of the excavation machines with draglines have been determined. 
These reliability changes were calculated separately for each subunit and finally the units of the dragline systems were determined to be more reliable. In order to find the interval between the estimated faults, the equations obtained from the distribution of the Poisson Analysis are used because of the proper distribution of the data. Depending on these equations, the mathematical calculations were performed to determine the next faults and postures of the draglines after the most recent breakdowns and downtimes, and the estimation of the actual data was observed. 
In order to estimate the duration of future faults, after the time interval between each consecutive fault of both draglines are determined. Thus, the coverage ratio method is considered to be a valid method for designing mechanical maintenance and planning This type of approach emphasizes the importance of the studies in terms of the performance of mining machines and will be the source and the basis for future studies.