Gemilerde ısı yalıtımı
Thermal insulation of ships
Yazar: GÖZDE DİLEK
Danışman: PROF. DR. İSMAİL CEM PARMAKSIZOĞLU
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Makine Mühendisliği Ana Bilim Dalı / Isı-Akışkan Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: Gemi Mühendisliği = Marine Engineering ; Makine Mühendisliği = Mechanical Engineering
Dizin: Gemiler = Ships ; Isı geçişi = Heat transfer ; Isı geçişi katsayısı = Heat transfer coefficient ; Isı kaybı = Heat loss ; Isı kazancı = Heat gain ; Isı yalıtımı = Heat insulation ; Isı yükü = Heat load ; Kanatlı yüzeyler = Finned surfaces ; Terleme = Sweating ; Yoğuşma = Condensation

Özet:
Gemilerin, ömürleri boyunca farklı iklim koşullarında seyir etmeleri, ısıl iletkenliği yüksek bir malzeme olan çelikten inşa edilmeleri ve bünyesinde bulunan mukavemet elemanlarının ısı geçişinde kanat etkisi göstermeleri sebebiyle, çalıştıkları bölgelerde karşılaşabilecekleri en yüksek ve en düşük dış ortam sıcaklarında bile yeterli olacak ısı yalıtım tasarımının yapılması büyük önem arz etmektedir. Gemilerde, yolcu ve mürettebat sağlığı ve konforu için uygun yaşama ve çalışma ortamı sağlamak, mahallerin ısıtılması ve soğutulması için gerekli olan enerji kullanımı azaltmak, yüklerin güvenli bir şekilde taşınmasını sağlamak, terleme ve yoğuşmayı önleyerek yapı elemanlarının ömürlerini uzatmak, yangına karşı koruma sağlamak ve gürültü kontrolü yapmak gibi amaçlar için yalıtım uygulaması yapılır.
Bu çalışmada, gemilerdeki ısı yalıtımı uygulamaları üzerine daha önce yapılmış araştırmalar ve çalışmalar incelenmiş, hesaplarda kullanılacak yöntemler derlenerek bir kaynak oluşturmak amaçlanmıştır.
Gemilerde ısı kaybı ve ısı kazancı hesaplarında kullanılacak yöntem anlatılmış, teknik şartnamede tasarım şartları ile ilgili özel bir ister bulunmaması durumda, hesaplarda kullanılacak değerler Ek A'da tablolar halinde sunulmuştur. Tezin son kısmındaki örnek hesaplar bölümü altında, bir geminin belirli bir kısmı için ısı kaybı ve ısı kazancı hesabı yapılmıştır. 
Isı yalıtımı hesaplamaları kısmında, yalıtım uygulaması yapılacak yüzeyin toplam ısı geçiş katsayısını hesaplamak için kullanılacak yöntem anlatılmış, düz yüzeyde ve mukavemet elemanlarında gerçekleşen ısı geçişi hesabı iki ayrı başlık altında incelenmiştir. Ek A'da örnek yalıtım uygulamaları için daha önce yapılmış çalışmalarda deneylerle elde edilmiş toplam ısı geçiş katsayısı değerleri derlenip sunulmuş ve farklı yalıtım uygulamalarının hesabını yapmak için kullanılacak katsayılar tablolar halinde verilmiştir. Aynı yalıtım uygulaması için kompartımanın iç ortam ile, hava ile ve deniz suyu ile temas halinde bulunması durumunda toplam ısı geçiş katsayısı hesabının nasıl yapılacağı, tezin son bölümünde örnekler üzerinden anlatılmıştır. Ayrıca terlemenin ve yoğuşmanın gemi bünyesindeki olumsuz etkileri ve yeterli ısı yalıtım tasarımını yapabilmek için teleme ve yoğuşma kontrolünün önemi üzerinde durulmuş, terleme ve yoğuşma kontrolü için kullanılacak yöntemler anlatılmıştır. Örnek hesaplar bölümü altında, bir yapı elemanı için terleme kontrolü yapılmış ve terlemeyi önleyecek yeterli yalıtım kalınlığının nasıl hesaplanacağı anlatılmıştır. Yine bu bölüm altında, örnek bir yapı elemanın iç katmanlarında yoğuşma meydana gelip gelmeyeceği, her ay için kontrol edilmiş ve yoğuşma kontrolü yapılan yapı bileşenin, kabul edilebilir yoğuşma kriterlerini sağlayıp sağlamadığı incelenmiştir.

Abstract:
Vessels sail under varies climate conditions. Their building material steel has very high heat conductivity and the stiffeners in their body lead to fin effect during heat transfer. Because of all these matters, it is very important to make heat insulation design by considering the minimum and maximum working temperatures for vessels. Insulation applications are done to be able to provide suitable accommodation and working environment for crew's and passengers' health and comfort, reduce the energy which is needed for decreasing / increasing the temperature in accommodation places, carry the loads safely, increase the lifetime of stiffeners by preventing sweating and condensation, take precautions against fire and control the noise.
In this study, the previously completed studies about heat insulation applications on vessels have been examined and the methods to be used for calculations have been gathered to be able to create a proper source.
In the first part of this study, general information about ship types and insulation types used in ships are given.
The methods to be used for heat loss and heat gain on ships are explained. The values to be used for calculations – against there are no specific design conditions on technical specification – are given by tables in appendix A. The effects of heat gains and heat looses from heat transfer on the boundary surfaces, solar heat gain, heat gain from people in the space, heat gain from lighting and heat gain from equipment on heating and cooling needs were examined under separate headings. Heat loss and heat gain calculations are done for specific spaces of a vessel at the last part of the thesis as example calculations. Heat gains and heat looses were calculated for the shower-toilet, two-person cabin and saloon on a sample vessel. In the sample calculation, the heating requirement for the shower-toilet was found as 562 W, the heating requirement for the two-person cabin was found as 210 W and the cooling requirement was found as 850 W, the heating requirement for the saloon was found as 750 W and the cooling requirement was found as 2138 W.
Under the heat insulation part, the method to be used for calculation of total heat transfer coefficient of the surface to be insulated have been explained.  In the calculations, a characteristic part consisting of flat surface and finned surface is considered. The heat transfer calculation on straight surface and stiffeners are examined under two separate subjects. It is explained how to calculate the total heat transfer resistance which is used to determine the specific heat loss occurring on the flat surface. In order to determine the equivalent convective heat transfer coefficient of the flat surface on which the strength elements are located, the correction procedure using the convective heat transfer coefficient and the radiative heat transfer coefficient is explained. In order to calculate the convective heat transfer coefficient used in the correction process, three different empirical formulas are given depending on the direction of the heat flow. 
The calculation of the total heat transfer resistance used to determine the specific heat loss in the finned surface is described. The correction procedure for determining the convective heat transfer coefficient of the strength elements is detailed on the example. The total heat transfer coefficient of the structural element was calculated by dividing the total specific heat loss of the flat surface and the finned surface by the total surface area.
In appendix A, total heat transfer coefficients specified with experiments in previously completed studies are provided for sample insulation applications and the coefficients to be used for calculations of different insulation applications are given via tables. In the last part of the thesis, the matter of how to calculate the total heat transfer coefficients if the compartment have boundary with inside air, outside air and seawater for same insulation application, has been clarified via examples. In the examples, a structural element supported by L profiles with dimensions of 15,24 x 10,16 x 0,64 cm is discussed. The distance between the strength elements is 91,44 cm. For an insulation application of 5 cm, total heat transfer coefficient through the ship's structure between inside compartment air and inside compartment air,  between inside compartment air and outside air and between inside compartment air and sea water were calculated. The results were compared with the results obtained by SNAME experiments for the same insulation application. In the first example, the calculation is made for the boundary between inside air and inside air, and the total heat transfer coefficient is found to be 1,685 W/m2K. When compared to the test results published by SNAME, there was a difference of 1,26%. In the second example, the total heat transfer coefficient is calculated for the same insulation application on the boundary between inside air and outside air. The total heat transfer coefficient was calculated as 1,822 W/m2K and it was found that there was a difference of 1,25% between the results of the test published by SNAME. In the third example, the total heat transfer coefficient is calculated for the same insulation application on the boundary between inside air and sea water. In this case, total heat transfer coefficient calculated as 1,797 W/m2K and it was found that there was a difference of 2,92% between the results of the test published by SNAME
Also, the negative effects of condensation and sweating on vessel's body have been explained and the methods to be used for sweating and condensation control have been clarified by pointing the importance of sweating and condensation control to be able to make proper heat insulation design.
Under the section of example calculations, sweating control for a ship's structure has been done and explained how to calculate suitable insulation thickness to be prevented the sweating. The ceiling of a compartment in contact with outside air at -7°C in winter conditions is considered. As a result of the calculations, it was seen that sweating would occur on the surface of the 5 mm ceiling panel. The additional resistance required to avoid condensation was calculated and the appropriate panel thickness to prevent condensation was calculated as at least 11 mm.
At the same part, it is explained step by step how to control the condensation that may occur in the inner layers of the structural component due to water vapor diffusion in the case of condensation control. Condensation control in a multi-layered structural component is detailed on an example and evaluated according to the condensation criteria in TS-825. The sample condensation control was carried out for 12 months on a ship which sails in Istanbul and the suitability of condensation criteria have been checked accordingly. It was observed that the condensation on the inner layers of the structural component started in November. According to calculations in November, December, January, February and March, a total of 2,356 kg/m2 of condensation occurred and In April, May and June, all of the condensation accumulated in the structural component was evaporated. 
In the conclusion part, the results and evaluations of all sample calculations are given. The application areas of this study and the importance of thermal insulation calculations on ships are mentioned. Suggestions have been made to improve the studies in this subject.