12th International Symposium on District Heating and Cooling

The <strong>12th</strong> <strong>International</strong> <strong>Symposium</strong> on District Heating and Cooling,September 5 th to September 7 th , 2010, Tallinn, EstoniaFig. 13 Annual heat supply and heat loss (Presentscheme)Fig. 17 Annual heat supply and heat loss (PEX Pipe)The heat loss comparison of each scheme can besummarized in Table 2.Table 2 Heat loss comparison of each scheme[unit:MWh]Supply Loss Heat loss rateFig. 14 Annual heat supply and heat loss (Alternative A)Present scheme 4863.7 681.4 14.01%Alternative A 4477.6 456.3 10.19%Alternative B 4317.1 516.3 11.96%Alternative C 4929 523 10.61%PEX Pipe 4691.2 508.9 10.83%Fig. 15 Annual heat supply and heat loss (Alternative B)Alternative B should supply heating water in thesummer season when it is not required for the supply ofheating water in order to supply hot water to theindividual home. From the comparison of Fig. 14 and15, Alternative B is more efficient than Alternative A inthe cold region.HEAT LOSS COMPARISON DUE TO THE CHANGEOF INSULATION THICKNESS,NOMINAL DIAMETERAND INSULATION MATERIALTable 3 shows a comparison among parameters whichaffect heat loss. There is frequent excessive design forthe nominal diameter of pipelines which are installed inboth the underground and the buildings. In thiscomparison the increases of insulation thickness by10 mm and 20 mm were considered. Also the decreaseof nominal diameter by 1 level was considered. It wastaken into consideration of insulation material changeand each combination of affecting parameters. In thiscomparison, the present popular design method ofpipelines and insulation was regarded as a referencefor 100% of heat loss and other alternatives wereevaluated from the reference heat loss relatively.Table 3 shows the result of relative comparison ofannual heat loss from the pipelines of the apartmentcomplex.Fig. 16 Annual heat supply and heat loss (Alternative C)110