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ACC JOURNAL 2019, Volume 25, Issue 1 DOI: 10.15240/ ul/004/2019-1-008
EFFICIENT HEATING AND COOLING WITH BOREHOLE HEAT EXCHANGERS
Axel Ge schel1; Ma kus Haack2; P asan h Sub amani; Lukas S öckmann; Thomas
Schä e ; Tom Wal e ; Tino Schü e; Jö n K immling
Hochschule Zi au/Gö li z, Uni e si y o Applied Sciences,
Fakul ä Wi scha swissenscha en und Wi scha singenieu wesen,
Theodo -Kö ne -Allee 16, 02763, Zi au, Ge many
e-mail: 1axel.ge sc[email p o ec ed]; [email protected]
Abs ac
G ound-sou ce hea pumps a e a sus ainable echnology o inc ease he use o enewable
ene gy sou ces. In o de o exploi he maximum po en ial o nea -su ace geo he mal ene gy,
op imiza ion concep s o bo ehole hea exchange sys ems ha combine hea ing and cooling
a e being de eloped a he Uni e si y o Applied Sciences Zi au/Gö li z. The objec i es o
his esea ch a e no only he educ ion o p ima y ene gy consump ion bu also he
de elopmen o p edic i e models o sys em planning, especially wi h espec o he
in luence o g oundwa e . Addi ionally, cons uc i e and economic aspec s o bo ehole hea
exchange sys ems a e e alua ed.
Keywo ds
Nea -su ace geo he mal ene gy; Hea pump; Bo ehole hea exchange ; Renewable ene gy;
Seasonal he mal ene gy s o age; G oundwa e low.
In oduc ion
The use o nea -su ace geo he mal ene gy o hea ing and cooling o buildings is an e icien
al e na i e o con en ional sys ems. U ilizing geological subsoil as a hea sou ce and sink
p o ides la ge po en ial o sa ing p ima y ene gy. By his, i helps o achie e ambi ious
ene gy ansi ion a ge s [1]. Toge he wi h panel hea ing and cooling sys ems, geo he mal
p obes a e pa icula ly sui able as unde g ound hea exchange s. G ound-sou ce hea pump
(GSHP) sys ems can un old hei maximum pe o mance capabili ies by using subsoil as
he mal s o age and in case o combined hea ing and cooling applica ions. Fo his pu pose
u he esea ch on planning me hods, p edic ion models and p ac ical ope a ional concep s
a e essen ial. The e o e, an in e disciplina y junio esea ch g oup a Zi au/Gö li z Uni e si y
o Applied Sciences was es ablished. This g oup consis s o esea che s specialized in he
ields o applied ma hema ics, enginee ing, geosciences and economics.
1 Op imiza ion Issues o Geo he mal Ene gy Sys ems
The main opic o esea ch deals wi h geo he mal ene gy supply concep s o non- esiden ial
buildings. In addi ion o co e ing hea ing demand, he ene gy supply sys ems in hese
buildings mo e and mo e o en ha e o co e cons uc ion and usage- ela ed cooling demand.
Howe e , complex ene gy demand s uc u es lead in planning p ac ice o en o unce ain ies
in he design o bo ehole hea exchange (BHE) ields [2]. The e o e, he op imal u iliza ion
o na u al egene a ion and ene gy s o age e ec s o he subsoil equi es he de elopmen o
new app oaches in he cons uc i e design o he BHE ield and he BHE i sel . Associa ed
p oblems ha e o be in es iga ed h ough pa ame e s udies wi h he aid o high- esolu ion
nume ical building and sys em simula ion models. The aim is o sys ema ize he decision-
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making p ocess o an op imal sys em con igu a ion (building and i s en i e echnical
equipmen ) by model-based op imiza ion and e alua ion o mul idimensional e iciency
c i e ia. Addi ional aspec s a e he assessmen o planning models wi h espec o hei
p edic ion accu acy and he e alua ion o o e as well as unde dimensioning e ec s in he
cons uc i e design o BHEs.
2 The In luence o Geology and G oundwa e
The hea anspo and possible he mal s o age in he subsoil a ies conside ably, depending
on local geological and hyd ogeological condi ions. Hence, he in luence o he p e ailing
geology and g oundwa e si ua ion in associa ion wi h he usage o nea -su ace geo he mal
ene gy is ano he key opic o his esea ch p ojec . De ailed knowledge o he he mal
p ope ies o he subsoil is essen ial o a p o ound design o BHE sys ems. In his con ex ,
he he mal conduc i i y and hea capaci y o he ock laye s as well as na u al unde g ound
empe a u e belong o he mos impo an p ope ies ha a e highly loca ion-dependen .
Un o una ely, hyd ogeological ac o s, especially con ec i e hea anspo induced by
g oundwa e low, a e o en neglec ed du ing sys em dimensioning. The eason o his is ha
cu en ly no well-enginee ed applica ion-o ien ed planning guide exis s o his speci ic
p oblem. In addi ion, gene a ion o cos ly and ime-consuming nume ical g oundwa e low
models a e o en no jus i ied in planning p ac ice [3, 4]. Howe e , especially when he
geological subsoil is used as a seasonal he mal s o age by combined hea ing and cooling
applica ions, he g oundwa e low induces con ec ion ha in luences he sys em pe o mance
nega i ely. The igno ance o g oundwa e low may lead o unde dimensioning o BHE
ields. Con a y o ha , g oundwa e low can inc ease he pe o mance o solo hea ing
applica ions. The u iliza ion o he subsoil ock o he mal s o age can inc ease he e iciency
o g ound-sou ce hea pump sys ems. The e o e, conside a ions o hyd ogeological ac o s in
he de elopmen o planning and design ools a e ine i able.
The abo e-men ioned ques ions a e being answe ed wi hin he amewo k o he mo-
hyd aulic modelling a Zi au/Gö li z Uni e si y o Applied Sciences. The pe meabili y
coe icien (k - alue) and he e ec i e po osi y o ele an ock laye s as well as he
hyd aulic g adien o g oundwa e belong o he hyd aulic aqui e p ope ies in he cen e o
a ac ion [3]. These hyd ogeological pa ame e s ha e o be sys ema ized wi h espec o hei
in luence on he hea anspo and i s consequences o he o e all sys em dimensioning.
Based on his, simpli ica ions can be de i ed o pe spec i e de elopmen s o new app oaches
in dimensioning o BHE ields.
3 BHE Tes Bench o Expe imen al In es iga ions
In o de o alida e he model h ough expe imen al in es iga ion a es bench equipped wi h
ex ensi e measu emen echnology is a ailable (Fig. 1). The sys em consis s o h ee BHEs o
ype PE-Xa 32 mm double-U wi h di e en dep hs a anged in iangula o m. Hea ing
ope a ion can be ealized by means o a buil -in comp ession chille . On he o he hand,
simula ion o he cooling ope a ion, as well as eeding o sola he mal ene gy, can be ealized
wi h he help o a gas-condensing boile . All main componen s as well as in eg a ed he mal
bu e s o age a e connec ed o each o he ia a comp ehensi e hyd aulic sys em (Fig. 2). All
BHEs, including he con ol p obe a he cen e, ha e a ull-leng h ieldbus senso sys em o
measu e he empe a u e e e y me e in dep h.
The sys em design allows ope a ions o single o mul iple BHEs wi h indi idually adjus able
low a es and de ined hea ing o cooling powe (hea ing powe : max. 132 kW, cooling
powe : max. 45 kW, ci cula ion pump: max. 12.6 m3/h). The ope a ing ange o he es bench
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goes om -10 °C o +90 °C in o de o map ope a ing poin s o comme cially a ailable hea
pump sys ems adequa ely.
In addi ion o sophis ica ed model alida ion, he es bench is used o de e mining he
loca ion-dependen s o age u iliza ion a e depending on bo ehole dep h [5]. By doing so, he
in luence o g oundwa e con ec ion on he mal s o age p ocess can also be analysed.
4 Cons uc i e Issues o BHEs
The analysis o cons uc i e and ma e ial- echnical issues o BHEs ep esen s ano he
impo an opic. He e, mechanically, he mally and chemically induced damages on
geo he mal p obes a e unde in es iga ion. BHE ins alla ion mis akes a e a equen cause o
mechanical damage. S uc u al damage in he g ou ma e ial caused by in ensi e and apid
os - haw cycles is one o he easons o he mally induced damage. As a possible
consequence, undesi ed annula gaps be ween g ou and p obe may o m. I a damaged
segmen o bo ehole back illing is loca ed in he dep h o aqui e s, his is c i ical wi h ega d
o he sys em igh ness, demanded by he au ho i ies. The same is ue in case o chemical
decomposi ions o he g ou caused by unsui able ma e ials in co osi e unde g ound
condi ions. Wi hou he p esence o g oundwa e , he ca i ies o de ec s wi hin he g ou ac
as a he mal insula ion, which leads o a educ ion in he BHE pe o mance. The e o e, he
objec i es o esea ch a e o analyze possible damages caused by means o mul iphysical
simula ions and o de i e ecommenda ions o educ ion o isk o damage.
Fig. 1: Tes bench ( om le o igh ): gas-
condensing boile , comp ession chille ,
he mal s o age
Fig. 2: Sys em scheme
Conclusion
The junio esea ch g oup in he ESF- unded esea ch p ojec „The mal s o age p ocess
a ound bo ehole hea exchange o hea ing and cooling o buildings wi h hea pumps“
p o ides he oppo uni y o examine he complex opics o nea -su ace geo he mal ene gy in
mul idisciplina y manne a Zi au/Gö li z Uni e si y o Applied Sciences. Wi h e e ence o
he inc easing demand o ene gy supply in buildings using hea pumps, an applica ion-
o ien ed con ibu ion o he planning p ac ice can be ealized.
Acknowledgmen
The Eu opean Union and F ee S a e o Saxony und he desc ibed esea ch p ojec . Fo
p o essional ad ice, many hanks also go o P o . D . Jens Meine .
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Li e a u e
[1] BUNDESMINISTERIUM FÜR WIRTSCHAFT UND ENERGIE (2015):
Ene giee izienzs a egie Gebäude. B ochu e. 146 pp. Be lin.
[2] BAYER, P.; de PALY, M.; BECK, M. (2014): S a egic op imiza ion o bo ehole hea
exchange ield o seasonal geo he mal hea ing and cooling. Applied Ene gy. Vol. 136,
pp. 445–453. DOI: 10.1016/j.apene gy.2014.09.029
[3] KÖLBEL, T. (2010): G undwasse ein luss au E dwä mesonden:
Geländeun e suchungen und Modell echnungen. Disse a ion. 146 pp. Ka ls uhe
Ins i u e o Technology.
[4] BAUER, D. (2011): Zu he mischen Modellie ung on E dwä mesonden und
E dsonden-Wä mespeiche n. Disse a ion. 121 pp. Uni e si y o S u ga .
[5] KRIMMLING, J. e al. (2015): Speiche o gänge im Um eld e ikale E dsonden on
Wä mepumpen. HLH. Vol. 66 (1): 19 pp.
Axel Ge schel; Ma kus Haack; P asan h Sub amani; Lukas S öckmann; Thomas Schä e ;
Tom Wal e ; Tino Schü e; Jö n K immling
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EFEKTIVNÍ KONCEPTY NA TOPENÍ A CHLAZENÍ POMOCÍ GEOTERMÁLNÍCH SOND
Na pozadí s ano ení ene ge icko-poli ických cílů předs a ují epelná če padla spojená se zemí
slibnou echnologii na zásobo ání budo e mickou ene gií. Na odk y í ne yuží aných
po enciálů po chní geo e mii jsou p o o na Vysoké škole Zi au/Gö li z y íjeny
op imalizační koncep y na zařízení geo e málních sond kombino aném opném a chladícím
p o ozu. Hla ni zaměření ýzkumu náleží úspoře p imá ní ene gie, jakož i zlepšení
p edik i ních modelů p o ná h zařízení, z láš ě s ohledem na li podzemních od.
Předmě em s udie jsou aké kons ukční a ekonomické aspek y sys émů geo e málních sond.
EFFIZIENTE HEIZ- UND KÜHLKONZEPTE MIT ERDWÄRMESONDEN
Vo dem Hin e g und ene giepoli ische Ziels ellungen [1] sind e dgekoppel e Wä mepumpen
eine zukun s ähige Technologie ü die he mische Gebäudeene gie e so gung. Zu
E schließung on ungenu z en Po enzialen in de obe lächennahen Geo he mie we den dahe
an de Hochschule Zi au/Gö li z Op imie ungskonzep e ü E dwä mesondenanlagen im
kombinie en Heiz- und Kühlbe ieb en wickel . Hie bei s eh die Einspa ung on
P imä ene gie ebenso wie die Ve besse ung on Vo he sagemodellen zu Anlagenauslegung,
insbesonde e un e Be ücksich igung on G undwasse ein luss, im Fokus de Fo schung.
Un e suchungsgegens and sind da übe hinaus kons uk i e und wi scha liche Aspek e on
E dwä mesondenanlagen.
EFEKTYWNE KONCEPCJE OGRZEWANIA I CHŁODZENIA PRZY POMOCY SOND
GEOTERMALNYCH
W odniesieniu do celów ok eślonych w zak esie poli yki ene ge ycznej pompy cieplne
połączone z ziemią s anowią obiecującą echnologię służącą do zasilania budynków ene gią
cieplną. W celu zbadania niewyko zys anego po encjału geo e mii powie zchniowej w Szkole
Wyższej Zi au/Gö li z op acowywane są koncepcje op ymalizujące u ządzenia sond
geo e malnych p acujących w ybie og zewania i chłodzenia. Badania skupiają się głównie
na oszczędności ene gii pie wo nej a akże udoskonaleniu modeli p ognos ycznych w celu
zap ojek owania u ządzeń, ze szczególnym uwzględnieniem wpływu wód podziemnych.
P zedmio em badań są akże aspek y kons ukcyjne i ekonomiczne sys emów sond
geo e malnych.