Pipe system life time cost

Energy will be increasingly precious Environment focus will grow The pipe system is expensive Life time expectancy is over 30 Years

What is life time cost ?

Investment cost– Pipe material– Pipe installation– Excavation and restoration– Inspection

Operation cost– Pumping– Heat loss

Maintenance cost– Repairs– Management

The Calculation Example

The model system supplies 10 MW Flow 90OC and return 50OC The pipe system is: 2 x 1000 m. DN 250 2 x 1500 m. DN 80 100 consumer connections a´100 kW

2 x 2500 m. DN 32 100 consumer connections a´10kW

2 x 2000 m. 18 mm. Cu-flex

Investment cost Thump rules

Pipes 380 000 EUR Insulation series 2 + 12% Double Pipes + 25% X-linked shrink joints +5% Pipe installation 50% of pipes Inspection 0- 50 000 EUR Excavation 100% of pipes Series 2 + 15% Double – 20% Asphalting 50% of pipes

Heat conductivity

PUR = SOLID +RADIATION +GAS

SOLID is not changing over time

RADIATION is not changing over time

GAS varies with the diffusion

SOLID +RADIATION app. 6 – 12 mW/mK depending upon the cell structure

The gas composition

The gas is Cyklopentane, CO2 and air Cyklopentane, CP 40% Carbon dioxide, CO2 55% Air ( N2 + O2 ) 5%

Lambda gas

Cyklopentane: 0,012 W/mK Carbon dioxide: 0,017 W/mK Air: 0,027 W/mK

Lambda values new Logstor pipes

Conti pipes: 0.024 W/mK Traditional pipes: 0,0275 W/mK Flex pipes: 0,025 W/mK

Lambda ageingTraditional vs. Conti w. Barrier

22

23

24

25

26

27

28

29

30

31

32

33

New 5 Years 10 Years 15 Years 20 Years 25 Years 30 Years

22 Cu-flexDN 32DN80DN250LR-ContiLR Cu-flex

mW/mK

German German failurefailure statisticstatistic

5

2000 25%

50%

4%

16%

5%

Weld seams

Joints

Casing+insulationDetectionsystemSundries

Swedish failure statisticsSwedish failure statistics

5

1998-200141%

45%

1%

12%

1%

Steel shells

Slide over

Weld joints

HDPE shrink

PEX shrink

Failure rates

With simple and cheap joints Joint failures may be > 0,5 failure/km./year

With PEX shrink joints or weld joints joint failures are < 0,05 failure/km./year

With low inspection rates Weld seam failures may be > 0,2 failure/km./year

With proper inspection Weld seam failures may be < 0,02 failure/km./year

Failure costs

The repair cost for a simple failure is estimated 3 000 EUR

The example: With cheap joints, repair cost is 20 000 EUR / year With PEX- and weld joints, it is < 2 000 EUR / year With low inspection, weld repair cost is 10 000 EUR / year With proper inspection, it is 1 000 EUR / year

Do it cheap and easy and you have high repair costs Do it right and you have low repair costs

Life time costsThe following picture compares:

“Series 1 cheap”: DN 25, DN 32, DN 80, DN 250 all traditional without barrier, cheap

joints and low inspection level.“Series 1 barrier”: 18 Cu-flex, DN 32, DN 80, DN 250 Conti pipes with barrier, PEX

joints and proper inspectionSeries 2 barrier: 18 Cu-flex, DN 32, DN 80, DN 250 Conti pipes with barrier, PEX

joints and proper inspectionDouble pipes: 18 Cu-flex, DN 32, DN 80, all double and DN 250 Conti pipes with

barrier, PEX joints and proper inspectionConst. Flow: is Series 1 cheap with constant flow pumps

Life time costs

0100020003000

4000500060007000

Serie 1cheap

Serie 1Barrier

serie 2Barrier

Double constflow

FailuresHeatlossPumpingInspectionAsphaltEscavationInstallationPipes

kEUR Present values

Life time cost

Calculation settings: Pumping energy 1% of total heat supply Constant flow pumps 3% of total heat supply Heat price 0,025 EUR/kWh Power price 0,06 EUR/kWh All amounts as present value over 20 years Inflation 2% Energy price rise 2% Bank interest 6%

The lessons are:

Do not save on inspection Do not accept “cheap” joints Keep your heat loss down Use flow controlled pumps