Bölgesel ısıtma sistemlerinde boru yalıtımı yoluyla enerji tasarrufu için optimum yalıtım kalınlığının belirlenmesi

Bir binanın ısıtılması için harcanan enerjinin azaltılmasında mekanik tesisat yalıtımı çok önemlidir. Özelikle bölgesel ısıtma boru hatlarındaki ısı kayıpları çok büyük olmaktadır. Bu hatların yalıtıkları takdirde sağlanacak enerji tasarrufu çok büyüktür. Bu çalışmada, Afyonkarahisar ili ve farklı ısıtma derece günlere göre bölgesel ısıtmadaki çeşitli boru çapları ve yakacak yakıtlar için optimum yalıtım kalınlığı, enerji tasarrufu ve geri dönüş süresi hesaplanmıştır. Bu nedenle borulardaki yalıtım ekonomisi için yaşam döngüsü maliyet (YDM) analizine dayanan bir optimizasyon modeli geliştirilmiştir. Yalıtım malzemesi olarak ekstrüde polistiren (XPS) kullanılmıştır. En fazla yıllık enerji tasarrufu fuel-oil yakıtından sağlanırken en az tasarruf ise jeotermal enerji için elde edilmiştir. Küçük çaplı borulara göre büyük çaplı borulardaki yalıtım ile de daha çok enerji tasarrufu yapılabilmektedir. Derece-gün değerlerin artması durumunda optimum yalıtım kalınlığı ve yıllık tasarruflar artarken geri dönüş sürelerinin azaldığı görülmüştür. Sonuç olarak, bölgesel ısıtma boru hatlarında uygun boru boyutlarının ve en uygun kalınlıkta yalıtım malzemelerinin seçimi ekonomik avantajlar sağlamaktadır.

Determination of optimum insulation thickness for energy saving through pipe insulation in district heating systems

The mechanical plumbing insulation is very important in reducing the energy expended for the heating of a building. Especially the heat losses in district heating pipelines are very large. The energy savings provided is enormous if the insulation is made in pipelines. In this study, for various pipe diameters and fuels in district heating the optimum insulation thickness, energy saving and payback period were calculated according to the Afyonkarahisar province and different heating degree-days. Therefore, an optimization model for insulation economy in pipes was enhanced based on the life cycle cost (LCC) analysis. The extruded polystyrene (XPS) as insulation material was used. The minimum annual energy savings were obtained for the geothermal energy while the maximum saving was provided from the fuel-oil as fuel. According to a small diameter pipes, the insulation of the large diameter pipes can be made more energy savings. It was shown that in case of an increase in the degreeday values, the payback periods decreased while the optimum insulation thickness and annual energy saving increased. As a result, the selection of the appropriate sizes of pipes and the appropriate thicknesses of insulation materials in district heating pipelines should provide economic advantages.

___

  • 1. Kaynaklı, O., 2008, “A study on residential heating energy requirement and optimum insulation thickness”, Renewable Energy, 33, 1164-1172.
  • 2. Stevens, A. 2012, “Steam Pipe Insulation, Mechanical Engineering, http://www.raeng.org.uk/education/diploma/maths/pdf/exemplars_engineering/2_SteamPipe.pdf [accessed on 23/2/2012].
  • 3. Sisman, N., Kahya, E., Aras, N., Aras, H., 2007, “Determination of optimum insulation thicknesses of the external walls and roof (ceiling) for Turkey’s different degree-day regions”, Energy Policy, 35, 5151-5155.
  • 4. Pavlik, Z., Cerny, R., 2009, “Hygrothermal performance study of an innovative interior thermal insulation system”, Applied Thermal Engineering, 29, 1941-1946.
  • 5. Uygunoğlu, T., Keçebaş, A., 2011, “LCC analysis for energy-saving in residential buildings with different types of construction masonry blocks”, Energy and Buildings, 43, 2077-2085.
  • 6. Kaur, J., Singh, S.P., Sawhney, R.L., Sodha, M.S., 1991, “Optimum layer distribution of a building component”, International Journal of Energy Reserch, 15, 11-18.
  • 7. Al-Turki, A.M., Zaki, G.M., 1991, “Cooling load response for building walls comprising heat storage and thermal insulation layers”, Energy Conversion and Management, 32, 235-247.
  • 8. Soylemez, M.S., Unsal, M., 1999, “Optimum insulation thickness for refrigeration applications”, Energy Conversion and Management, 40, 13-21.
  • 9. Kecebas, A., Kayveci, M., 2010, “Effect on optimum insulation thickness, cost and saving of storage design temperature in cold storage in Turkey”, Energy Education Science and Technology Part A Energy Science and Research, 25, 117-127.
  • 10. Zaki, G.M., Al-Turki, A.M., 2000, “Optimization of multi-layer thermal insulation for pipelines”, Heat Transfer Engineering, 21, 63-70.
  • 11. Wechsatol, W., Lorente, S., Bejan, A., 2001, “Tree-shaped insulated designs for the uniform distribution of hot water over an area”, International Journal of Heat and Mass Transfer, 44, 3111- 3123.
  • 12. Kalyon, M., Sahin, A.Z., 2002, “Application of optimal control theory in pipe insulation”, Numerical Heat Transfer Part A-Applications, 41, 391-402.
  • 13. Sahin, A.Z., 2003, “Optimal insulation of ducts in extraterrestrial applications”, International Journal of Energy Research, 28, 195-203.
  • 14. Sahin, A.Z., Kalyon, M., 2004, “The critical radius of insulation in thermal radiation environment”, Heat and Mass Transfer, 40, 377-382.
  • 15. Öztürk, İ.T., Karabay, H., Bilgen, E., 2006, “Thermo-economic optimization of hot water piping systems: A comparison study”, Energy, 31, 2094-2107.
  • 16. Karabay, H., 2007, “The thermo-economic optimization of hot-water piping systems: A parametric study of the effect of the system conditions”, Strojniski Vestnik-Journal of Mechanical Engineering, 53, 548-555.
  • 17. Keçebaş, A., Alkan, M.A., Bayhan, M. 2011, “Thermo-economic analysis of pipe insulation for district heating piping systems”, Applied Thermal Engineering, 31, 3929-3937.
  • 18. Holman, J.P., 1992, “Heat transfer”, Seventh Edition, McGraw-Hill Book Co., New York.
  • 19. ASHRAE, 1989, “Heat transfer”, Ashrae Handbook-Fundamentals, chapter 22, pp. 22.1-22.21, Atlanta.
  • 20. Afyonkarahisar Meteoroloji Bölge Müdürlüğü, 2012, Kişisel görüşme, Afyonkarahisar.
  • 21. Başoğul, Y., Keçebaş, A., 2011, “Economic and environmental impacts of insulation in district heating pipelines”, Energy, 36, 6156-6164.
  • 22. Keçebaş, A., 2012, “Determination of insulation thickness by means of exergy analysis in pipe insulation”, Energy Conversion and Management, 58, 76-83.
  • 23. Duffie, J.A., Beckman, W.A., 2006, “Solar Engineering of Thermal Processes”, Third Edition, Wiley Interscience, New York.
  • 24. Teknik Yayıncılık A.Ş., 2012, “Yakıt fiyatları”, Tesisat Enerji Teknolojileri ve Mekanik Tesisat Dergisi, http://www.tesisat.com.tr/ [Erişim tarihi: 20/03/2012].
  • 25. Keçebaş, A, 2011, “Performance and thermo-economic assessments of geothermal district heating system: A case study in Afyon, Turkey”, Renewable Energy, 36, 77-83.
  • 26. Buyukalaca, O., Bulut, H., Yilmaz, T., 2001, “Analysis of variable-base heating and cooling degreedays for Turkey”, Applied Energy, 69, 269-283.