A PRACTICAL METHOD FOR DETERMINATION OF ECONOMIC INSULATION THICKNESS OF STEEL, PLASTIC AND COPPER HOT WATER PIPES

Year 2020, , 72 - 86, 06.01.2020

Nuri Alpay Kürekci , Mehmet Özcan

https://doi.org/10.18186/thermal.671651

Cited By: 1

Abstract

Hot water systems are being extensively used in residential as well as industrial contexts. Choice of insulation material’s thickness has a significant effect on total cost. The purpose of this study was to develop a simplified but accurate empirical method that allows to determine the optimum thicknesses of the insulation materials that are applied on the hot water pipes. In the first step, a comprehensive mathematical model was constructed for the calibration and validation purposes. Then, the heat transfer between the flow inside the pipe and the external environment was thermally modeled; followed by a calculation of fuel and insulation costs. After that, the total cost analysis method was applied in order to define the optimum insulation thickness. Later an empirical method was developed based on the mathematical model. Finally, the accuracy of the empirical method was tested, using a wide range of physical conditions as well as different insulation materials, pipe and fuel types. The standard optimum insulation thickness values were founded same for the all pipe types with the identical diameters. The heat losses can be reduced around 89, 88 and 83% by application of optimum insulation thickness to steel, copper and plastic pipes respectively. Larger pipes have higher net savings and lower payback periods. Fuel-oil is the least economic heating solution; therefore the application of insulation brings higher profits than the other fuels. Prediction accuracy of the empirical method is higher for the steel and copper pipes than the plastic pipes. An average matching rate of 91.4% indicated that the new method is a valid and time-saving alternative, which can be used in pipe insulation applications.

Keywords

Heat Transfer Pipes, Optimum Insulation Thickness, , Energy Saving, Thermo-Economic Analysis, Mathematical Modeling, Thermal Insulation

References

• [1] World energy statistics, IEA World Energy Statistics and Balances, 2016; doi:10.1787/03a28cba-en.
• [2] Kaygusuz K., Avci A. C., Potential and utilization of solar energy policies in Turkey, Journal of Engineering Research and Applied Science, 2019; 8(1), 1087-1098.
• [3] Energy Saver: Tips on Saving Money & Energy at Home (Book), U.S. Department of Energy, 2014; pp. 7–11., doi:10.2172/1134089.
• [4] Masatin, V., Volkova, A., Hlebnikov, A., Latosov, E., Improvement of district heating network energy efficiency by pipe insulation renovation with PUR foam shells, Energy Procedia, 2017; 113, 265-269.
• [5] Zhang, L., Wang, Z., Yang, X., Jin, L., Zhang, Q., Hu, W., Thermo-economic analysis for directly-buried pipes insulation of district heating piping systems, Energy Procedia, 2017; 105, 3369-3376.
• [6] Daşdemir, A., Ural, T., Ertürk, M., Keçebaş, A., Optimal economic thickness of pipe insulation considering different pipe materials for HVAC pipe applications. Applied Thermal Engineering, 2017; 121, 242-254.
• [7] Öztürk, İ. T., Karabay, H., Bilgen, E., Thermo-economic optimization of hot water piping systems: A comparison study, Energy, 2006; 31(12), 2094-2107.
• [8] Özel, G., Açıkkalp, E., Görgün, B., Yamık, H., Caner, N., Optimum insulation thickness for piping system using exergy and environmental methods, International Journal of Global Warming, 2017; 11(1), 107-123.
• [9] Keçebaş, A., Alkan, M. A., Bayhan, M., Thermo-economic analysis of pipe insulation for district heating piping systems, Applied Thermal Engineering, 2011; 31(17-18), 3929-3937.
• [10] Kürekci N.A., Türkiye’nin Dört Derece Gün Bölgesinde Borular İçin Optimum Yalıtım Kalınlığı, TMMOB Tesisat Mühendisliği Dergisi, 2013; vol. 136, pp. 25-40.
• [11] Stainless Steel Pipes Measures and Features, Stainless Steel Pipes, www.steellines.com/stainless_steel_pipes-s106.html.
• [12] Çakmanus, İ., İman H.,Mekanik Tesisat Sistemlerinde Kullanılan Borular, Türk Tesisat Mühendisleri Dernegi, Vol. 33, Issue 10.
• [13] PPR-C Pipes and Fittings, Plastherm, www.plastherm.com/pprc-pipes-and-fittings/.
• [14]PPRC Pipe – Pipes - Fırat Plastic, www.firat.com/en-us/indoor-piping-system/cold-hot-water-pipe-systems/pprc-product-range/pprc-pipe?section=374.
• [15]HDPE-Pipe-for-Water-Supply-Dimension, PPR Pipe Fittings, C&N Aquatherm, www.pprpipefittings.com/wp-content/uploads/2015/07/HDPE-Pipe-for-water-supply-dimension.jpg.
• [16] Cengel, Y. A., Klein, S., Beckman, W., Heat transfer: a practical approach, 1998; Vol. 141, New York: McGraw-Hill.
• [17] Churchill, Stuart W., Humbert H.s. Chu., Correlating equations for laminar and turbulent free convection from a horizontal cylinder, International Journal of Heat and Mass Transfer, 1975; Vol. 18, Issue 9, 1975, pp. 1049–1053.
• [18] Churchill, S. W., M. Bernstein., A Correlating Equation for Forced Convection from Gases and Liquids to a Circular Cylinder in Crossflow, Journal of Heat Transfer,1977; Vol. 99, Issue 2, pp. 300. doi:10.1115/1.3450685.
• [19] Emissivity Table, ThermoWorks, 2018; www.thermoworks.com/emissivity_table.
• [20] PPR Piping System, Mechanical Properties and Application Information for Niron PPR, PPR Supply, 2016; pprsupply.com/content/mechanical properties and application information for niron ppr 2016.pdf.
• [21]Specification - Insulation of Pipe & Duct Work XPE/IXPE, Proflex Thermal Insulation, proflexinsulation.com/specifications/.
• [22]Polietilen Boru İzoleleri, KAR-EL Klimaflexler Güncel Fiyat Listesi, 2018;www.kar-el.com.tr/fliste2.aspx?id=244.
• [23] Yakıt Fiyatları Karşılaştırması, Igdas, 2017; www.igdas.istanbul/yakit-fiyatlari-karsilastirmasi/index.html/.
• [24] Ashouri, M., Astaraei, F. R., Ghasempour, R., Ahmadi, M. H., Feidt, M. Optimum insulation thickness determination of a building wall using exergetic life cycle assessment, Applied Thermal Engineering, 2016; 106, pp. 307-315.
• [25] OECD Long-Term interest rates, Main Economic Indicators, 2007; Vol. 2017, Issue 7, doi:10.1787/mei-v2017-7-en.