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, Estoniafor axial heat loss and the thermal conductivity, thermalresistance and overall heat loss are calculated.Test results institute oneAs the actual measurement data are not available dueto the correction factor, only the calculated values canbe discussed in this paragraph. As soon as the actualmeasurements become available this section will beupdated. Furthermore the results are not given forexactly 60, 70 and 80 °C due to the fixed power supplywith no temperature set point, the displayed results arecalculated heat loss values at the set temperatures tomake the data more interpretive. For this calculationthe linearization method described in the Europeanstandard [1] is used. In Graph 4 the data from Table 3is presented as a graph.Table 3, Results test institute one for the Flexalen 600productsHeat loss of the Flexalen 600 series in W/m tested attest institute oneProduct 40 °C 50 °C 60 °C 70 °C 80 °C50A25 5.6 8,8 11.9 15.1 18.3160A90 9.1 15.1 21.1 27.1 33.0200A110 9.8 15.1 20.5 25.8 31.2Heat loss [W/m]40302010Heat loss results test institute oneAn update to this paper will be made as soon as theFlexalen 600 results will become available.Testing method institute twoThe method used by this institute is generally the sameas the method used by Thermaflex; however the testfacility itself is different.Physical test facilityThe testing facility at institute two consists of atemperature controlled room, kept at the prescribed23 °C. As a heat source a heating probe, consisting ofa 2 m test section and two 50 cm end guards is used.At the time of writing no further information on the testfacility was available. This paragraph will be updatedwhen this information becomes available.Method of testingPrior to testing, the sample is prepared by placingthermocouples in various locations on the inner servicepipe and outer casing. Subsequently the sample isplaced in the temperature controlled room and theheating probe is inserted. By setting the power supplyto a calculated value for all three heating coils theheating process of the sample is started. Because ofthe low fixed value of the power supply, this heating willtake approximately 5 to 8 hours. After the desiredtemperature is reached at the test section as well as atthe guarded ends, the actual test is performed. The testconsists of a power reading during a 30 min cyclewhere het temperature of the test section and guardedends may not exceed the limit of an yet unknownbandwidth.Test results test institute twoThe test results of institute two are given in Table 4 andGraph 5. As not all data was available during writingthere tables and graphs will be updated.040 50 60 70 80Temperature inner service pipe [°C]Flexalen 50A25Flexalen 160A90Flexalen 200A110Graph 4, Results test institute one for the Flexalen 600productsTEST INSTITUTE TWOTable 4, Results test institute two for the competitiveproductsHeat loss of competitive products in W/mtested at test institute twoSample 40 °C 50 °C 60 °C 70 °C 80 °C90DN25 1.95 4.00 6.02 8.06 10.09For the second test institute in this research, aninstitute using the same guarded end method ischosen. This makes it possible to provide a correctcomparison between the test results and not only thetesting method. The tests carried out by test institutetwo at the time of writing are of competitive productsonly as the facility was already running on full capacity.255