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1876-6102 © 2017The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling.
The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling
Assessing he easibili y o using he hea demand-ou doo
empe a u e unc ion o a long- e m dis ic hea demand o ecas
I. And ića,b,c*, A. Pinaa, P. Fe ãoa, J. Fou nie b., B. Laca iè ec, O. Le Co ec
aIN+ Cen e o Inno a ion, Technology and Policy Resea ch -Ins i u o Supe io Técnico,A . Ro isco Pais 1, 1049-001 Lisbon, Po ugal
bVeolia Reche che & Inno a ion,291 A enue D ey ous Daniel, 78520 Limay, F ance
cDépa emen Sys èmes Éne gé iques e En i onnemen -IMT A lan ique, 4 ue Al ed Kas le , 44300 Nan es, F ance
Abs ac
Dis ic hea ing ne wo ks a e commonly add essed in he li e a u e as one o he mos e ec i e solu ions o dec easing he
g eenhouse gas emissions om he building sec o . These sys ems equi e high in es men s which a e e u ned h ough he hea
sales. Due o he changed clima e condi ions and building eno a ion policies, hea demand in he u u e could dec ease,
p olonging he in es men e u n pe iod.
The main scope o his pape is o assess he easibili y o using he hea demand –ou doo empe a u e unc ion o hea demand
o ecas . The dis ic o Al alade, loca ed in Lisbon (Po ugal), was used as a case s udy. The dis ic is consis ed o 665
buildings ha a y in bo h cons uc ion pe iod and ypology. Th ee wea he scena ios (low, medium, high) and h ee dis ic
eno a ion scena ios we e de eloped (shallow, in e media e, deep). To es ima e he e o , ob ained hea demand alues we e
compa ed wi h esul s om a dynamic hea demand model, p e iously de eloped and alida ed by he au ho s.
The esul s showed ha when only wea he change is conside ed, he ma gin o e o could be accep able o some applica ions
( he e o in annual demand was lowe han 20% o all wea he scena ios conside ed). Howe e , a e in oducing eno a ion
scena ios, he e o alue inc eased up o 59.5% (depending on he wea he and eno a ion scena ios combina ion conside ed).
The alue o slope coe icien inc eased on a e age wi hin he ange o 3.8% up o 8% pe decade, ha co esponds o he
dec ease in he numbe o hea ing hou s o 22-139h du ing he hea ing season (depending on he combina ion o wea he and
eno a ion scena ios conside ed). On he o he hand, unc ion in e cep inc eased o 7.8-12.7% pe decade (depending on he
coupled scena ios). The alues sugges ed could be used o modi y he unc ion pa ame e s o he scena ios conside ed, and
imp o e he accu acy o hea demand es ima ions.
© 2017 The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and
Cooling.
Keywo ds: Hea demand; Fo ecas ; Clima e change
Ene gy P ocedia 116 (2017) 365–373
1876-6102 © 2017 The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling.
10.1016/j.egyp o.2017.05.083
10.1016/j.egyp o.2017.05.083
A ailable online a www.sciencedi ec .com
ScienceDi ec
Ene gy P ocedia 00 (2017) 000–000
www.else ie .com/loca e/p ocedia
1876-6102 © 2017 The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling.
The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling
Sensi i i y Analysis On The Axial Soil Reac ion
Due To Tempe a u e Induced Pipe Mo emen s
Ingo Weidlicha*
aHa enCi y Uni e si ä Hambu g, Übe seeallee 16, 20457 Hambu g, Ge many
Abs ac
Seen om an in e na ional pe spec i e p einsula ed bonded pipe sys ems domina e in hea dis ibu ion. These pipe sys ems a e
usually bu ied in sand and soil-pipe in e ac ion hinde s he mal s ains, which make economic solu ions o bow-and T-sec ions
possible. Fo s a ic design pipe-soil in e ac ion mus be known as accu a e as possible. Howe e , se e al pa ame e s a e
in luencing he quan i y o he expec ed soil eac ion. Main in luencing ac o s a e dependen on he used bedding ma e ial and
geome y. Fu he mo e cu en esea ch esul s made addi ional soil-phenomena e iden , which a e ha dening e ec s and s ess
edis ibu ion du ing ope a ion. A new calcula ion app oach o he axial soil eac ion was de eloped in 2015 based on exis ing
es esul s and nume ical simula ions. A sensi i i y analyses we e ca ied ou o es ima e he signi icance o ele an pa ame e s
and he exis ing calcula ion app oaches. This pape iden i ies he signi ican pa ame e s and sugges s pa ame e se s o lowes
and highes axial soil eac ion. Two main bounda y si ua ions a e aken in o accoun a) i s mo emen b) du ing ope a ion.
©2017The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and
Cooling.
Keywo ds: bu ied pipe design, pipe soil in e ac ion, ic ion o ce
1. In oduc ion
Seen om an in e na ional pe spec i e pipe laying acco ding o s a e o he a in hea dis ibu ion is p ima ily
based on p einsula ed bonded pipe sys ems. These pipe sys ems a e usually bu ied in sand. The in e ac ion o soil
* Co esponding au ho . Tel.: 49-40-42827-5700
E-mail add ess: ingo[email p o ec ed]
A ailable online a www.sciencedi ec .com
ScienceDi ec
Ene gy P ocedia 00 (2017) 000–000
www.else ie .com/loca e/p ocedia
1876-6102 © 2017 The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling.
The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling
Sensi i i y Analysis On The Axial Soil Reac ion
Due To Tempe a u e Induced Pipe Mo emen s
Ingo Weidlicha*
aHa enCi y Uni e si ä Hambu g, Übe seeallee 16, 20457 Hambu g, Ge many
Abs ac
Seen om an in e na ional pe spec i e p einsula ed bonded pipe sys ems domina e in hea dis ibu ion. These pipe sys ems a e
usually bu ied in sand and soil-pipe in e ac ion hinde s he mal s ains, which make economic solu ions o bow-and T-sec ions
possible. Fo s a ic design pipe-soil in e ac ion mus be known as accu a e as possible. Howe e , se e al pa ame e s a e
in luencing he quan i y o he expec ed soil eac ion. Main in luencing ac o s a e dependen on he used bedding ma e ial and
geome y. Fu he mo e cu en esea ch esul s made addi ional soil-phenomena e iden , which a e ha dening e ec s and s ess
edis ibu ion du ing ope a ion. A new calcula ion app oach o he axial soil eac ion was de eloped in 2015 based on exis ing
es esul s and nume ical simula ions. A sensi i i y analyses we e ca ied ou o es ima e he signi icance o ele an pa ame e s
and he exis ing calcula ion app oaches. This pape iden i ies he signi ican pa ame e s and sugges s pa ame e se s o lowes
and highes axial soil eac ion. Two main bounda y si ua ions a e aken in o accoun a) i s mo emen b) du ing ope a ion.
©2017The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and
Cooling.
Keywo ds: bu ied pipe design, pipe soil in e ac ion, ic ion o ce
1. In oduc ion
Seen om an in e na ional pe spec i e pipe laying acco ding o s a e o he a in hea dis ibu ion is p ima ily
based on p einsula ed bonded pipe sys ems. These pipe sys ems a e usually bu ied in sand. The in e ac ion o soil
* Co esponding au ho . Tel.: 49-40-42827-5700
E-mail add ess: ingo.weidlich@hcu-hambu g.de
© 2017 The Au ho s. Published by Else ie L d.
Pee - e iew unde esponsibili y o he Scien i ic Commi ee o The 15 h In e na ional Symposium on Dis ic Hea ing and Cooling.
366 Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373
2Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000
and pipe hinde s he mal s ains, making economic solu ions o bow- and T-sec ions possible. Rega ding he s a ic
design, pipe-soil in e ac ions mus be known as accu a e as possible.
Nomencla u e
k0ea h p essu e coe icien a es = 1-sinϕ'
Ge ec i e weigh o he pipe illed wi h wa e
σ e ec i e soil s ess a pipe axis
o g anula soils:
σ γB*Hw+γBW*(Z-Hw) o Hw< Z
σ γs*Z o Hw≥Z
Zdep h o he pipe axis
Hwdep h o g ound wa e able
γBuni weigh o he soil
γBw buoyan weigh o he soil
γSweigh o he sa u a ed soil
Daou e diame e
µ coe icien o ic ion
δ con ac ic ion angle
ϕ'in e nal soil ic ion angle
κl ac o o he ela ionship be ween ini ial s ess s a e and subsequen s ess s a e
σ ,a g a e age con ac p essu e on he pipe pe ime e
F ,u ul ima e ic ion o ce
∆T empe a u e inc emen
κl ac o o he ela ionship be ween ini ial s ess s a e and seconda y s ess s a e
Hdep h o o e bu den o he op o he pipe
D ela i e densi y o soil bedding
αT he mal expansion coe icien
Asa ea o s eel medium pipe
EYoung’s Modulus
FRul ima e ic ion o ce
l0leng h o he gliding sec ion
Howe e , se e al pa ame e s a e in luencing he quan i y o he expec ed soil eac ion [1]. Main in luencing ac o s
a e he bedding ma e ial u ilized and i s pa ame e s (e.g. a e age e ec i e uni weigh , compac ness o coe icien o
la e al ea h p essu e) and he geome y o he pipe and ench (e.g. dep h o he pipe (c own) below he su ace o
ex e nal pipe diame e ). Fu he mo e, cu en esea ch esul s e iden ly showed he in luence o addi ional
phenomena, such as ha dening e ec s and s ess edis ibu ion du ing ope a ion [2]. A new calcula ion app oach o
he axial soil eac ion was de eloped in 2015 based on exis ing es esul s and nume ical simula ions [3].
Soil eac ions ele an o he design o dis ic hea ing pipelines a e di ided in o wo g oups: Axial soil eac ion and
la e al soil eac ion. Since he magni ude o he expec ed la e al soil eac ion is a cu en esea ch opic [4] he axial
soil eac ion, which is he skin ic ion among he pe ime e o he pipe, was sugges ed o be desc ibed su icien ly
by s anda d calcula ion app oaches in he las decades. Howe e , majo de ia ions be ween calcula ed eac ions and
measu emen o he bea ing beha iou o dis ic hea ing pipes in si u ha e been epo ed by enginee s qui e
equen ly. Agains his backg ound, a new app oach o calcula ing he skin ic ion was de eloped aking in o
accoun con empo a y esea ch esul s.
2. S a e o he a
The Eu opean s a e o he a o he calcula ion o pipe skin ic ion o dis ic hea ing pipes is de ined in EN13941
Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373 367
Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000 3
[5]. Acco ding o his app oach, he skin ic ion FRis assumed o be p opo ional o he adial con ac p essu e
a ound he pipe and may be calcula ed using equa ion (1).













−+
+
=
2
0
2
*****
2
1
a
Ba R
D
GD
k
F
πγπσµ
(1)
The e m in b acke s desc ibes he esul ing ea h p essu e ac ing on he pipe. Howe e , se e al o he
me hodologies a e a ailable o he calcula ion o he esul ing ea h p essu e on pipes (e.g Ma s on [6], Spangle
[7], Leonha d [8]). µis he coe icien o ic ion acco ding o COULOMB,gene ally anging be ween µ=0.3 o 0.4
o no mal condi ions, c . acco ding o EN 13941 [5]. Al e na i ely,equa ion 2 may be used o he calcula ion o µ.






== 3
'*2
an an
ϕ
δµ
(2)
Since he in e nal ic ion angle anges be ween ϕ‘=32° o 40° o sands, equa ion (2) leads o µ=0.39…0.5.
Conside ing as mo emen s,µ=0.6 isgi en in [5], which is 1.5- imes highe han he alue occu ing due o no mal
mo emen .
3. Ini ial s ess condi ion
Rega ding cons an geome ic bounda ies, he ini ial s ess condi ion a e ins alla ion depends on he p ope ies
o he bedding ma e ial. In o de o a oid se lemen s o he su ace, a high deg ee o compac ness is usually wan ed
o he ench back ill. The compac ness achie ed wi hin he ench in luences he uni weigh o he soil and he
ea h p essu e coe icien [1]. Thus, an inc eased coe icien o ea h p essu e p obably occu s and has o be aken
in o accoun when calcula ing he maximum ic ion o ce in he sense o a wo s case scena io.
4. S ess condi ions du ing ope a ion
Du ing ini ial ope a ion o he pipeline, wo main e ec s ha e o be aken in o accoun o he desc ip ion o axial
soil eac ion: 1. Due o empe a u e dependen adial expansion ∆ e he no mal soil s ess inc eases along he
pe ime e o he pipe and 2. Tempe a u e d i en axial expansion leads o axial pipe mo emen s esul ing in a
ha dening e ec due o dila an soil eac ion. Bo h e ec s a e illus a ed in Figu e 1.
368 Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373
4Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000
Fig. 1. Two majo e ec s du ing ini ial ope a ion.
The adial pipe-soil in e ac ion was in es iga ed in a wo-dimensional nume ical model by ACHMUS in 1995 [9].
Axial ha dening e ec s due o dila ancy a e known om bu ied s uc u al componen s such as piles and ancho s.
These e ec s we e conside ed o unde s and skin ic ion o dis ic hea ing pipelines by he au ho in 2007 [10].
Achmus calcula ed 1995 ypical pa ame e combina ions o sand wi h di e en ela i e densi ies. As a measu e
o empe a u e dependence, he ac o κl, was de ined:
)0(
,
,
)0(
,
,
)100(
)100(
u
u
a g
a g
lF
KTF
KT =∆
=
=∆
=
σ
σ
κ
(3)
The esul s indica ed ha his ac o signi ican ly depends on he ela i e densi y o he sand, as well as he
o e bu den heigh H. Achmus de i ed equa ion (4) o he calcula ion o κl om he esul s ( alid o ∆T=100K).
Fo lowe ∆T, κlmay be in e pola ed.
l
DmH *22.1][*1.018.1 +−=
κ
(4)
Sys ema ic undamen al in es iga ions on he in e ac ing e ec s o adial expansion and ha dening due o
dila ancy a e missing. Howe e , ew isola ed single esul s exis bu an o e all e alua ion has no been ca ied ou
ye . An example o cu en esul s is he in es iga ion o HUBER e al. om 2014 [2], which a e shown in ex ac s
in Figu e 2.
Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373 369
Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000 5
Fig. 2. Resul s om HUBER e al. [2].
HUBER e al. obse ed an inc eased ic ion o ce, ep esen ed by κl,Hube =1.5 o a empe a u e inc emen o
∆T=50K. Medium dense bounda y condi ions o he bedding we e epo ed, which is ela ed o D ≈0.5. A e
in e pola ion, equa ion (4) deli e s κl,Achmus=1.36 o ∆T=50K. Thus, expe imen al 3d- esul s app oxima ely showed
alues 10% abo e he esul s o he 2d-app oach. Values o his magni ude o axial ha dening we e obse ed be o e
wi hou empe a u e load in [11].
Me ging he wo-dimensional nume ical in es iga ions o ACHMUS wi h he axial ha dening e ec due o
dila ancy, a mo e ealis ic app oach o he calcula ion o ic ion o ce du ing ini ial loading is assumed, see
equa ion (5).
Achmusl
R
KTR
l
DmH
F
F
*34.1][*11.030.11.1*
,
0,
100,
mod,
+−===
=∆
κκ
(5)
Conside ing epea ed he mal loading, he soil con ac p essu e will dec ease due o s ess edis ibu ion in he
su ounding soil. In p esen p ac ice, he ini ial ic ion o ce is assumed o d op by 50% simula ing he esidual s a e
upon cyclic loading acco ding o EN13941 [5]. The ac ual phenomena o ic ion deg ada ion we e in es iga ed by
he au ho , whe eas addi ional equa ions desc ibing s esses occu ing du ing ope a ion a e gi en e.g. in [10].
5. Sensi i i y analysis
A sensi i i y analysis was ca ied ou conside ing wo bounda y pa ame e se s esul ing in low and high ic ion,
s. Table 1. A high empe a u e inc emen ∆T was used o ope a ion empe a u es up o 120°C acco ding o
EN13941 [5].

370 Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373
6Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000
Table 1. Pa ame e se .
Pa ame e
Low ic ion
High ic ion
O e bu den heigh
H=0.8 m
H=0.8 m
Nominal Diame e /Ou e Diame e
DN100/200
DN100/200
Tempe a u e Inc emen
∆T=100K
∆T=100K
Uni weigh o soil
γ=16kN/m³
γ=20kN/m³
Ea h p essu e coe icien
K=0.5=1-sin(ϕ’=30°)
K=1.0
Coe icien o ic ion
µ=0.36= an(2*(ϕ’=30)/3)
µ=0.54= an(2*(ϕ’=43)/3)
Rela i e densi y
Loose
Dense, D
=0.7
Equa ions
(1)
(1) and (5)
Fu he mo e, equa ion (1) was used acco ding o EN13941 ep esen ing he lowe bounda y. In addi ion, κl,mod
was applied o desc ibing he uppe bounda y. A common single beam s a ic model was used o he sensi i i y
analysis, which is shown in Figu e 3.
Fig. 3. Single beam model o DH-pipe.
Acco ding o equa ions (6) and (7), he leng h o he gliding sec ion l0and he maximum displacemen umax may
be de i ed o his model.
R
sT
F
EAT
l
***
0
∆
=
α
(6)
s
R
EA
lF
u2
2
0
max =
(7)
The esul s o he calcula ions a e gi en in able 2. The a io o high and low ic ion is 5.41. This di e ence
demons a es he impo ance o choosing accu a e pa ame e s o he bedding condi ions in he ield in o de o
calcula e he ic ion o ces occu ing co ec ly.
Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373 371
Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000 7
Table 2. Resul s.
Resul s
Low ic ion
High ic ion
Ra io High
s. Low
Skin ic ion F
R
2.33 kN/m
12.6 kN/m
5.41
Gliding leng h l
0
137.26 m
25.35 m
0.18
Maximum displacemen u
max
84.6 mm
15.6 mm
0.18
Basing on he examina ions on a u u e de elopmen o he supply low empe a u es o dis ic hea ing
conduc ed by LUND e al. in 2014 [12], he sensi i i y analysis was enhanced o a u u e scena io acco ding o he
empe a u e de elopmen shown in Fig. 4.
Fig. 4. Fu u e supply empe a u e acco ding o [12].
Fo a ic i ious a e age ambien empe a u e Ta=20°C, he ele an empe a u e inc emen anges he e be ween
∆T1880=180K and ∆T2050=30K. The esul s o umax and l0unde low ic ion condi ion acco ding o Table 1 a e
gi en o dec easing ∆T in Fig. 5.
372 Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373
8Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000
Fig. 5. Signi icance o dec easing supply empe a u e.
This simple pa ame ic s udy o he single beam sys em shows a signi ican educ ion o maximum displacemen
and gliding leng h as well as he ela ed s ains and s esses. Fo a u u e empe a u e inc emen o ∆T=30K only a
displacemen o 7.1 mm emains which is less han 10% o he displacemen o ∆T=100K.
6. Conclusions
A e a e iew o scien i ic esul s om nume ical and expe imen al in es iga ions, highe alues o he ic ion
o ce du ing ini ial empe a u e loading a e expec ed o dense bedding condi ions. Since wo soil-mechanical
phenomena ha e been examined independen ly in he pas , a new empi ical calcula ion app oach is sugges ed. A
sensi i i y analysis is done, applying wo bounda y pa ame e se s, showed majo disc epancies in ic ion o ces
assessing he magni ude o he cha ac e is ic designs. Howe e , he p esen ed me ged calcula ion app oach o
ini ial skin ic ion is based only on limi ed da a. Be o e p ac ical implemen a ion he app oach shall be e alua ed by
ield measu emen s and addi ional expe imen al in es iga ions.
Finally i mus be no ed o he sugges ed u u e scena ioswi h dec easing supply empe a u es in dis ic hea ing
ne wo ks s a ic enginee ing and soil-pipe in e ac ion issues may play a mino ole in he u u e.
Re e ences
[1] I. Weidlich, D. Wijewick eme, „Fac o s in luencing soil ic ion o ces on bu ied pipes used o dis ic hea ing“ 13 h In e na ional
Symposium on dis ic hea ing and cooling, Copenhagen Sep embe 2012, (2012).
[2] M. Hube , D. Wijewick eme, “The mal In luence on axial pullou esis ance o bu ied dis ic hea ing pipes”, The 14 h In e na ional
Symposium on Dis ic Hea ing and Cooling, S ockholm, (2014).
[3] I. Weidlich, „Zu Reibungsk a bei Inbe iebnahme eine Fe nwä melei ung“, (On he ic ion o ce du ing aking in o ope a ion a dis ic
hea ing pipeline), Eu oHea &Powe , 44.Jg., He 12, Publishe : EW Medien und Kong esse GmbH, F ank u am Main, pages: 32-36, (2015).
[4] M. Achmus, M. G ehl, “Cyclic la e al soil esis ance on dis ic hea ing pipes”, The 14 h In e na ional Symposium on Dis ic Hea ing and
Cooling, S ockholm, (2014).
[5] EN 13941:2010, „Design and ins alla ion o p einsula ed bonded pipe sys ems o dis ic hea ing“, CEN/TC 107, Deu sches Ins i u ü
No mung e.V. No menausschuss Heiz- und Raumlu echnik (NHRS), Beu h Ve lag, Be lin, (2010).
[6] M. Spangle , S esses in p essu e pipe-lines and p o ec i e cas ing pipes. Jou nal o S uc u al Enginee ing (82), pp. 1-33 (1956).
Ingo Weidlich / Ene gy P ocedia 116 (2017) 365–373 373
Ingo Weidlich /Ene gy P ocedia 00 (2017) 000–000 9
[7] M.G. Spangle and R.L. Handy, „Soil Enginee ing“. Ha pe and Row, Publishe s, New Yo k, (1982).
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