Lityum iyon pil hücresinin termal karakterizasyonu
Yükleniyor...
Dosyalar
Tarih
2019
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Bursa Teknik Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Enerjiye duyulan ihtiyacın artması ile birlikte enerji kaynaklarının azalması, çevre kirliliği, enerji üretimi ve tüketimi arasındaki farkın hızla büyümesi sonucu alternatif kaynaklara ihtiyaç duyulmuştur. Enerji talebindeki hızlı artışın karşılanabilmesi için enerji kaynaklarından elde edilen enerjinin verimli bir şekilde depolanması ve ihtiyacı karşılayacak en uygun dönüşümlerin geliştirilmesi, en yararlı çözümlerden biri olacaktir. Son yıllarda yüksek enerji yoğunlukları ve uzun çevrim ömrü sayesinde, lityum-iyon piller yoğun olarak araştırılmaktadırlar. Li-ion piller genellikle 0°C derecenin altındaki sıcaklıklarda şiddetli güç kaybına ve aşırı yüksek sıcaklıklarda termal kaçak riskinde artışla karşı karşıya kalmaktadırlar. Bu nedenle, sistem sıcaklığını kabul edilebilir bir aralıkta kontrol etmek ve tüm sistem boyunca sıcaklık homojenliğini korumak için bir termal yönetim sistemi gereklidir. Bu tezde, iç sıcaklık dinamiklerini açıklayan genel bir modelleme metodolojisi ve silindirik bir pil hücresindeki sıcaklık dağılımı üzerinde durulmuştur. Hücreler arasındaki sıcaklık dağılımı daha tutarlı olan ve kolay boyutlandırılabilir bir li-iyon batarya tasarımı amaçlanmıştır. Bu tasarım yapılırken Zhenpo ve çalışma arkadaşlarının yaptığı çalışmadaki matemetiksel modelleme ve kimyasal yapı baz alınmıştır. Samsung 18650 li-iyon pil kullanarak sıcaklık problemlerini önceden tahmin etmek ve çözümlemek için yeni bir sonlu hacim modeli geliştirilmiştir. Batarya paketinin ısı akış alanı verilerini hesaplamak için CFD tabanlı olan FloEFD yazılımı kullanılmıştır. Termal kamera ile yüzey sıcaklığı ölçülen hücre ve modülün FloEFD programı ile analizi yapılmıştır. Analiz sonucunda elde edilen maksimum sıcaklık değerleri tek hücre için 34,02°C, 14 tane lityum iyon bataryadan oluşan modül için 40,16°C olarak bulunmuştur. Termal kamera ile ölçülen sıcaklık sonuçları ise tek hücre ve modül için sırasıyla 32.9°C ve 40°C olarak ölçülmüştür. Lityum-iyon pilin çevreye yaydığı ısı nedeniyle bağlı bulunduğu cihaza verdiği zararı engellemek ve batarya sıcaklığını düşürebilmek amacıyla, batarya polimer(PA66) bir malzeme ile çevrilmiştir. Kaplama sonrası FloEFD yazılımı ile yapılan analiz sonucu maksimum sıcaklık 37,71°C, termal kamera yardımıyla test sonucu sıcaklığı ise 38,8°C olarak ölçülmüştür. Analizler 25°C çevre şartlarında, ışınım etkisi ve yerçekimi etkileri dikkate alınarak yapılmıştır. Çalışma sonunda lityum iyon batarya için kurulan ısıl model doğrulanmıştır. Polimer katkılı bir malzeme ile çevrilen bataryaların sıcaklık dağılımlarının düzenli olduğu ve bataryalarda sıcaklık problemi olmadığı tespit edilmiştir.
Alternative sources were needed as a result of the increase in the need for energy, the decrease in energy resources, the environmental pollution, and the rapid growth of the difference between energy production and consumption. In order to meet the rapid increase in energy demand, efficient storage of energy from energy sources and development of the most suitable transformations to meet the need will be one of the most useful solutions. In recent years, due to their high energy density and long cycle life, lithium-ion batteries have been extensively researched. Li-ion batteries often face severe power loss at temperatures below 0°C and an increased risk of thermal leakage at extremely high temperatures. Therefore, a thermal management system is required to control the system temperature within an acceptable range and to maintain temperature homogeneity throughout the system. In this thesis, a general modeling methodology explaining the internal temperature dynamics and temperature distribution in a cylindrical battery cell is emphasized. It is intended to design a li-ion battery which is more consistent and easy resizable, with temperature distribution between cells. This design is based on the mathematical modeling and chemical structure of Zhenpo et al. A new finite volume model has been developed to predict and solve temperature problems using the Samsung 18650 li-ion battery. FloEFD was used as CFD software to calculate the heat flow area data of the battery pack. Cell, module and package whose surface temperature was measured by thermal camera were analyzed with FloEFD program. The maximum temperature values obtained at the end of the analysis were found to be 34,02°C for single cell and 40,16°C for module consisting of 14 lithium ion batteries. Temperature results measured by thermal camera were measured as 32.9°C and 40°C for single cell and module, respectively. The battery is surrounded by a polymer (PA66) material to prevent damage to the device to which it is connected due to the heat emitted by the lithium-ion battery and to reduce the battery temperature. The maximum temperature was measured as 37,71°C by the FloEFD software and the temperature of the test was 38,8 °C by the thermal camera after the coating. The analyzes were carried out at 25°C environmental conditions considering radiation effect and buoyancy effects. At the end of the study, the thermal model established for the lithium ion battery was verified. It was found that the temperature distributions of the batteries packaged with polymer material are regular and there is no temperature problem in the batteries.
Alternative sources were needed as a result of the increase in the need for energy, the decrease in energy resources, the environmental pollution, and the rapid growth of the difference between energy production and consumption. In order to meet the rapid increase in energy demand, efficient storage of energy from energy sources and development of the most suitable transformations to meet the need will be one of the most useful solutions. In recent years, due to their high energy density and long cycle life, lithium-ion batteries have been extensively researched. Li-ion batteries often face severe power loss at temperatures below 0°C and an increased risk of thermal leakage at extremely high temperatures. Therefore, a thermal management system is required to control the system temperature within an acceptable range and to maintain temperature homogeneity throughout the system. In this thesis, a general modeling methodology explaining the internal temperature dynamics and temperature distribution in a cylindrical battery cell is emphasized. It is intended to design a li-ion battery which is more consistent and easy resizable, with temperature distribution between cells. This design is based on the mathematical modeling and chemical structure of Zhenpo et al. A new finite volume model has been developed to predict and solve temperature problems using the Samsung 18650 li-ion battery. FloEFD was used as CFD software to calculate the heat flow area data of the battery pack. Cell, module and package whose surface temperature was measured by thermal camera were analyzed with FloEFD program. The maximum temperature values obtained at the end of the analysis were found to be 34,02°C for single cell and 40,16°C for module consisting of 14 lithium ion batteries. Temperature results measured by thermal camera were measured as 32.9°C and 40°C for single cell and module, respectively. The battery is surrounded by a polymer (PA66) material to prevent damage to the device to which it is connected due to the heat emitted by the lithium-ion battery and to reduce the battery temperature. The maximum temperature was measured as 37,71°C by the FloEFD software and the temperature of the test was 38,8 °C by the thermal camera after the coating. The analyzes were carried out at 25°C environmental conditions considering radiation effect and buoyancy effects. At the end of the study, the thermal model established for the lithium ion battery was verified. It was found that the temperature distributions of the batteries packaged with polymer material are regular and there is no temperature problem in the batteries.
Açıklama
Anahtar Kelimeler
Enerji, Energy, Makine Mühendisliği, Mechanical Engineering
