Testing Laboratory of Heat-Tech Center Veolia Energy Warsaw, Puławska 2 Street, 02-566 Warsaw/ Heat-Tech Center, Skorochód-Majewskiego 3 Street, 02-104 Warsaw GENERAL INFORMATION HTC Testing Laboratory carries out complex tests of preinsulated elements and insulations used for district heating pipelines. Since 2009 the laboratory has been listed as the unit recommended by the association Euroheat & Power for performing tests of the preinsulated pipes. Since 2003, the laboratory is approved by the Polish Centre for Accreditation for the applied test methods. The current scope of accreditation No. AB 414 can be found at website www.pca.gov.pl. The laboratory is equipped with the unique test stands, designed and constructed by the HTC employees. These are the stands for testing: thermal conductivity coefficient (for the cylindrical insulations and preinsulated pipes) shear strength radial creep soil stress (sandbox and water impermeability) accelerated ageing process - before the thermal conductivity test - before the shear strength test. The laboratory is also equipped with the following measuring devices such as: stereoscopic microscope for determining the average cell size Instron testing machine for compressive and tensile strength tests gas pycnometer for determining the closed cells content in rigid porous materials toothed dial indicator sidle calliper height gauge electronic calipers electronic scales moisture analyzer for determining the sand moisture content. 1 TESTS CARRIED OUT IN HTC TESTING LABORATORY thermal conductivity coefficient λ, W/mK The tests are based on the standards ISO 8497, EN 253 and PB-06 The tests are performed on cylindrical insulations. Thermal conductivity is a fundamental parameter for the thermal properties of the DH insulations. The maximum acceptable value of the thermal conductivity of polyurethane foam used in preinsulated pipes is λ 50 = 0,029 W/mK. thermal conductivity coefficient after ageing λ, W/mK The artificial ageing process precedes the thermal conductivity test. The artificial ageing process is carried out in the heating chamber with the outer casing temperature t = 90 C, much higher than the average ambient temperature of the pipeline operating under the ground t = 8 C. soil stress test of the preinsulated joint assembly The test is based on the standard EN 489 and PB-19 There are two stages: sandbox test and water impermeability test. The main aim of the soil stress test is to check the strength of the joint assembly against the forces influencing the joint during its operation. The sandbox test is to simulate the conditions influencing the preinsulated joints during operation. The water impermeability test is used to evaluate the results of the sandbox test and it is to assess the tightness of the joint by water immersion. radial creep resistance ΔS, % The test is based on the standard EN 253 and PB-18 The test is carried out at 140 C in 10000 hours. Its main aim is to check the strength of the preinsulated pipe insulation against long term influence of the constant force. axial and tangential shear strength τ, MPa The test is based on the standard EN 253 and PB-17 The aim of the test is to check the ability of the preinsulated bonded pipe system to withstand the ground reaction force. The minimum acceptable stress value according to EN 253 standard is: τ tan = 0,20 MPa τ ax 23 C = 0,12 MPa τ ax 140 C = 0,08 MPa
shear strength test after ageing τ, MPa The test is based on the standard EN 253:2009 and PB-17 The accelerated ageing process is carried out at the service pipe temperature greatly exceeding the actual continuous operating temperature of the PUR foam. The bonded pipe system, which expected life in continuous operating temperature 120 C is 30 years, is tested at t = 160 C in 3600 hours or at t = 170 C in 1450 hours. Tangential or axial shear strength test is done after accelerated ageing process. compressive strength σ, MPa The test is based on the standards EN 253, EN 826, PN-C-89071 and PB-20 The test is to determine the compressive strength in radial direction at 10% relative deformation. Minimum compressive strength of PUR foam, used in preinsulated pipelines insulation, is σ 10av = 0,3 MPa. elongation at break A, % The test is based on the standard PN EN 253 and PB-20 The outer casing pipe of the preinsulated system is subjected to the test. The minimal elongation at break of the HDPE casing pipe is A = 350 %. apparent density ρ, kg/m 3 The test is based on the standards EN ISO 845, EN 1602, EN 13470, EN 253 and PB-20 Apparent density is an important parameter of the insulation material endurance. High apparent density provides a proper mechanical strength of the foam as well as shear and creep strength of the preinsulated pipe. The higher is the density of the new insulation, the worse are the thermal insulation properties, because the thermal conductivity coefficient increases. average cell size d, mm The test is based on the standard PN-EN 253 and PB-20 The aim of the test is to determine linear dimension of the insulation cells in radial direction. Average size of PUR foam cell in preinsulated pipes is d av = max 0,5 mm. closed cells content ψ, % The test is based on the standards EN 253, EN ISO 4590 method no 1 and PB-20 The test is carried out with the usage of the gas pycnometer, by measuring the change of the pressure. The corrected closed cells content of the PUR foam is ψ oav = min 88%. voids and bubbles The test is based on the standards EN 253 and PB-20 Voids and bubbles shall not exceed 5% of the cross section area of the insulation. All other individual spaces shall be less than 1/3 of the nominal insulation thickness between steel pipe and casing. water absorption in a high temperature W AV, % The test is based on the standards PN-EN 253 and PB-20 The aim of the test is to check the thermal insulation resistance to damage due to inundation with hot water. The maximum PUR foam water absorption after 90 minute-boiling is WA Vav = max 10%. water absorption by immersion W AV, % The test is based on the standard PN-C-89084 and PB-20 The aim of the test is to check the absorbability of thermal insulation material by measuring the buoyancy of the sample immersed in cold water. PUR foam water absorption by immersion after 24 and 168 hours is respectively WA Vav = max 3% and WA Vav = max 4,5 %. center line deviation e, mm The test is based on the standard EN 253 and PB-20 The aim of the test is to check the coaxiality of the casing pipe in the relation to the steel service pipe. The center line deviation means that the insulation thickness in pipe cross section is non-uniform which complicates making a proper joint assembly. preinsulated twin pipe tests The test is based on the standard EN 15698-1 and PB-20 The tests carried out in HTC Laboratory: - end alignment of forward and return service pipes, - distance between forward and return service pipes, - twisting of service pipes, - center line deviation. dimensional stability The test is based on the standard PN-C-89083 and PB-20 The aim of the test is to verify whether in rigid porous insulation of foam shells or of the preinsulated pipes, exposed to a certain temperature at certain time, there were no irreversible changes of linear dimensions in each of three mutually perpendicular directions and to determine the degradation temperature of the insulation material. temperature distribution in double-layer insulation The test is based on PB-07 procedure designed by HTC. The aim of the test is to determine the temperature distribution in the cross-section of the insulation, used to verify the thickness of the insulation layers and to check whether the inner layer of the insulation will sufficiently reduce the impact of the heating medium temperature on the outer layer. The test also allows to determine the unit heat losses of the double-layer insulation. 2
TEST EQUIPMENT IN HTC LABORATORY 1. Thermal conductivity coefficient test stand Fig. 1 Test stand SB-6 pipe apparatus Test stand so called pipe apparatus (Fig. 1) has been constructed according to standard EN ISO 8497. The main elements of the stand: - thermostatic chamber - to keep the constant temperature of the air surrounding the tested sample - testing pipe - to introduce the heat flow into the insulation with assumed temperature and providing zero heat flow in axial directions. recording. The technical construction eliminates the convection effect during the tests. The stand can be used for testing the pipeline insulations: DN20, DN50, DN80 and DN250. The tests can be carried out on the semi-cylindrical and cylindrical insulation shells and on the preinsulated pipes. 2. Axial and tangential shear strength test stand The main elements of the stand (Fig. 2): - testing machine to implement the action of shear forces on the sample - temperature control system - to heat the sample service pipe up to 140 C and maintain this temperature in the permissible deviation limits during initial heating process and during the entire test - computer control system. The value of the force, displacement and speed of the crosshead are recorded. The stand is used for testing the preinsulation pipes with diameters: DN 400. 3. Radial creep resistance test stand The main elements of the stand (Fig. 3): - hydraulic loading system which is responsible for the implementation of continuous loading perpendicular to the axis of the symmetry of the service pipe - temperature control system, which is responsible for heating the service pipe up to the required temperature and maintaining that temperature throughout the test period, 10000 hours, recording. Fig. 2 Shear strength test stand Fig. 3 Radial creep resistance test stand 4. Soil stress test stand The main elements of the stand are two modules: "sandbox" and "water tank". We can test the joints made on the preinsulated pipes with diameters up to DN 150. Module sandbox (Fig. 4, 5) consists of the following elements: - rectangular steel structure 1.80 x 1.00 x 1.80 m without a cover - one meter thick sand layer, which covers tested joint assembly - actuator with control system realizing axial forces by moving the sample forward and backward without pause. Setting and counting the number of cycles of movement are provided by the IT software. - temperature control system, which is responsible for heating the steel service pipe during the whole testing time recording 3
Module "water tank (Fig. 6) is to performing water impermeability test, and is a horizontal cylindrical steel tank, which realizes of the external pressure effects on the joint assembly by flooding at a constant temperature and constant pressure. Water tank stand is equipped with a temperature and pressure control systems. Fig. 7 Heating chamber for preinsulated pipes ageing before thermal conductivity test Fig. 4, 5 Sandbox Fig. 8 Accelerated ageing process stand before shear strength test NEW EQUIPMENT Fig. 6 Water tank 5. Artificial aging process stand Artificial ageing process before thermal conductivity test (Fig. 7) is carried out in the heating chamber equipped with temperature control system. The chamber is responsible for keeping the complete pipe assembly at an elevated temperature for a certain time. Accelerated aging process before shear strength test (Fig. 8) is carried out on the stand which enables keeping the service pipe at an elevated temperature while the casing is exposed to an ambient temperature. The stand is equipped with temperature control system and continuous data recording system. Fig. 9 Test stand SB-6 plate apparatus Test stand so called plate apparatus heat flow meter apparatus (Fig. 9) has been constructed according to standard EN ISO 8301. The tests can be carried out on the plate insulation: 30 mm x 30 mm x t, where t is the thickness of insulation. 4
Fig. 10 Heating chamber Exsiccation process before thermal conductivity test (Fig.10) is carried out in the heating chamber equipped with temperature control system. The chamber is responsible for keeping the insulation at an elevated temperature for a certain time. Fig. 11 Climatic chamber Artificial ageing process before thermal conductivity test (Fig. 11) is carried out in the climatic chamber equipped with temperature and humidity control system. OUR CUSTOMERS DH companies: ZEC Łódź, PEC Stargard Szczeciński, PEC Bełchatów, OPEC Puławy, PEC Kutno, GPEC Gdańsk, PEC Suwałki, SYDKRAFT EC Słupsk, Szczecińska Energetyka Cieplna, Energetyka Cieszyńska, Therma Bielsko-Biała, ZEC Katowice, MPEC Chełm, Energoterm Toruń, Vattenfall Polska, PEC Jelenia Góra, Energetyka Cieplna Opolszczyzny, Toruńska Energetyka Cergia SA., PEC Tychy, KPEC Bydgoszcz, SPEC Warszawa, Dalkia Warszawa, OPEC Gdynia, Dalkia Łódź, Dalkia Poznań, Veolia Energia Warszawa, Veolia Czech Republic Preinsulated pipes manufacturers: FINPOL Warszawa, ZPU Jońca Międzyrzecz, STAR-PIPE Poznań, LOGSTOR Polska, PRIM Lublin, ISOPLUS Katowice, Elzas Leszno, ISOPLUS Sondershausen Germany, Logstor Denmark, KVY - Pipe OY Finland Insulation and raw material systems manufacturers: MAT Łódź, ELEKTROTERMEX Ostrołęka, EURICO Ożarów Mazowiecki, HYDROMAT Kobylnica Widziano, Euro Invest Bud Poznań, METALPUR Bydgoszcz, POLYCHEM Poznań, IZOTERM Cząstków Mazowiecki; FOLIMPEX Warszawa, IZOTERMA Przygodzice, MINOVA EKOCHEM S.A. Siemianowice Śląskie, PURINOVA Tarnów/ Bydgoszcz,, MAGWENT Zduńska Wola, BASF Śrem, INTER WW Tuchom, HIT TERM Celestynów, Eutherm Ożarów Mazowiecki, PRODEX Warszawa, KUTE JA EHITUS AS (Tartu, Estonia) Joint assemblies and thermo shrinkable products manufacturers: RADPOL Człuchów, BRUGG Płochocin, PROB Radom, ENERGOFIT Człuchów, CEGA Warszawa, TERMOGUM Warszawa, Kamitech Dzierżoniów, Sarmat-Inżynieria (Minsk, Belarus), CANUSA Canada, HANTECH Sweden, MITTEL Sweden, BERRY PLASTICS Belgium Institutes: Institute of Nuclear Chemistry and Technology Warszawa, Industrial Chemistry Research Institute Warszawa 5