pipe system life time cost
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
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