Recommendations for a heat district heating network Göran Johansson Technical manager Philippe Terrien Country Manager

Transcription

1 Recommendations for a heat district heating network Göran Johansson Technical manager Philippe Terrien Country Manager Göran Johansson and Philippe Terrien 1

2 District heating District cooling - Annual turnover of 35MEuro employees. - Annual production of : Pipes ( 300 km ) Fittings & Joints Göran Johansson and Philippe Terrien 2

3 UK market Four year development from 0 to nearly 2.5MEuro Supply Partner with major energy companies (Eon, Veolia, Cofely) Network adviser to local authorities Technical support to consultants Selection of qualified installers Göran Johansson and Philippe Terrien 3

4 Reference list Sweden ( 2/3 ) Bosnia and Hercegovina Bulgaria China Croatia Czech Republic Denmark Egypt Estonia Finland France Germany Jordan Iceland UK Latvia Lithuania Norway Romania Russia Serbia and Montenegro The Netherlands Vietnam Göran Johansson and Philippe Terrien 4

5 The service life of a district heating network depends on: Ageing of the foam Infiltrating moisture = corrosion Construction/ Design mistake Göran Johansson and Philippe Terrien 5

6 Foam Ageing: Accelerated test has shown : At least 30 years of service at continuously 120 C At least 80 years of service at continuously 110 C The foam is today not the limit for a long service time. Göran Johansson and Philippe Terrien 6

7 Infiltrating moisture = corrosion The welding and jointing process is essential for a working product. Based on Swedish statistics we know that a number of problems has been reduced: Average year Average PPS Average PPS ,06 damages/1000 m pipe*year 0,009 damages/1000 m pipe*year 0,003 damages/1000 m pipe*year Göran Johansson and Philippe Terrien 7

8 Infiltrating moisture = corrosion Regarding jointing we have today: Better jointing material Better jointing systems Better skilled fitters (In Sweden, training & attitude) Göran Johansson and Philippe Terrien 8

9 The jointing process Jointing the pipes is the most important installation step. The jointing material shall always be: Clean Warm Dry at the installation stage. Göran Johansson and Philippe Terrien 9

10 The foaming process Before foaming the joint the temperature of the: Pipe material shall be between C. Liquids minimum +20 C. Göran Johansson and Philippe Terrien 10

11 Surveillance system All pipes are supplied with alarm wires. The wires shall be connected in accordance with an alarm drawing. The surveillance can be made from a central point. Göran Johansson and Philippe Terrien 11

12 A certified joint fitter in Sweden shall have: 1. Completed a practical test in the field, including theory test with the controller (Certificate of Competence for licensing) 2. Received certification from at least one joint supplier of eligibility in the current type of joint 3. Certificate of practical experience Göran Johansson and Philippe Terrien 12

13 Faulty construction/design Faulty construction/design is a less common problem where/when the designers are experienced and know where pitfalls are. Göran Johansson and Philippe Terrien 13

14 Design Guide lines for design are available in EN Force controlled actions Low cycle fatigue Dilatation controlled actions Allows cold installation Project classes Göran Johansson and Philippe Terrien 14

15 Thermal expansion Göran Johansson and Philippe Terrien 15

16 σ = E*α*ΔT σ ~= 2,5*ΔT Example: ΔT = 50 C σ = stress E = modulus of elasticity α = coefficient of linear expansion ΔT =temperature difference P = force A = cross sectional area P DN50 = kp P DN250 = kp P DN500 = kp The force is twice as big for cold installed pipes Göran Johansson and Philippe Terrien 16

17 Frictional length F= Frictional force FDN50 = ~145 kp/m FDN250 = ~530 kp/m FDN600 = ~1100 kp/m Göran Johansson and Philippe Terrien 17

18 σ Relatation between force and movement L= Friction length For DN300: PΔT=105 C = 150 ton L = 190m Fr (Friction force) = 780 kp/m ΔX = 127 mm Göran Johansson and Philippe Terrien 18

19 The bend will move sideways. DN 250/450 ΔT = 60 C P = 64 ton L = 100m ΔX = 37 mm 37 mm Göran Johansson and Philippe Terrien 19

20 Foam cushions/pads can withstand up to a 70% compression. Mineral wool can withstand up to 50%compression The cushions are mounted standing (version A) around the pipe (type B) Configuration B should be avoided around shrinking sleeves. Göran Johansson and Philippe Terrien 20

21 Basically there are two different ways to install preinsulated pipes: Preheating Meaning that the pipes are warm (60-75 C) at refilling the trench Lower stress in the steel pipes. Small movement in expansion points Dry joints at installation Lower risk for buckling at uncovering the pipe. Cold installation Meaning that the pipes are cold at refilling the trench. High stress in the steel pipes Great movement in expansion points. Restrictions regarding bends, miterings and cones Easy to install in dense urban area Göran Johansson and Philippe Terrien 21

22 Preheated systems : Avoid bends unless one leg is short. Max mitering angle is 3 Furnish single pipe branches (>15m) with a discharging dog leg Göran Johansson and Philippe Terrien 22

23 Cold installed systems: 1-89 All bends, reductions are not allowed in the fixed zone Miterings are not allowed in the fixed zone Branches (> 15m) at single pipes shall be furnished with discharging dog leg. Göran Johansson and Philippe Terrien 23

24 Requirements for project classes Project class Welding control Documentation A 5% Generalised documentation, B 10% Generalised documentation C 20% Specific documentation required General operational data Data related to the pipeline Specification for quality control Göran Johansson and Philippe Terrien 24

25 Göran Johansson and Philippe Terrien 25

26 A conclusion is that it is possible to build modern district heating network with a long service life when: Using approved products Using skilled designers Careful installation by experienced workers (welding and jointing) Göran Johansson and Philippe Terrien 26

27 Thank you for your interest!!!! Philippe Terrien Country Manager M: E: Goran Johansson Technical Director M: E: Göran Johansson and Philippe Terrien 27