PresentationPDF Available

Parametric study for the long term energetic performance of geothermal energy piles

Authors:

Abstract

A short and coincise presentation summarizing the parametric study reported in the conference paper available at https://doi.org/10.1088/1755-1315/352/1/012011
DD.MM.YYYY
PARAMETRIC STUDY FOR THE LONG
TERM ENERGETIC PERFORMANCE OF
GEOTHERMAL ENERGY PILES
Andrea Ferrantelli
Department of Civil Engineering and Architecture
Tallinn University of Technology
07.11.2019
1st Nordic ZEB+, Trondheim
TALLINN UNIVERSITY OF TECHNOLOGY
MOTIVATION:
Energetic performance and renewable resources
Energy piles (GHE): U-shaped
heat exchangers inserted inside
the foundation piles of buildings.
Simulations often focus only on
heat transfer in the foundation
soil.
A full parametric study including
the heat pump system above.
A. Ferrantelli, J. Fadejev and J. Kurnitski - Parametric study for the long term energetic performance of geothermal energy piles
Bao, Xiaohua, et al. "Thermal properties of cement-based composites
for geothermal energy applications.“ Materials 10.5 (2017): 462.
TALLINN UNIVERSITY OF TECHNOLOGY
METHOD
IDA-ICE model for a commercial hall-type building in Finland
(Helsinki climate data ~5000 HDD w. Tb=20C), validated in [1].
Simulations: 20 years. Many different building models depending on
heat pump power, total length, specific heat extraction rate (W/m).
Soil type: clay.No stratification, no thermal storage.
[1] Fadejev J and Kurnitski J (2015), Energy
and Buildings 106 23 34 ISSN 0378-7788
A. Ferrantelli, J. Fadejev and J. Kurnitski - Parametric study for the long term energetic performance of geothermal energy piles
TALLINN UNIVERSITY OF TECHNOLOGY
RESULTS
Technical parameters:
Foundation piles: L=15m-30m
Design heat load:360 kW.
Annual heating demand: 168 MWh.
Spacing: 6m, 4.5m, 3m.
A. Ferrantelli, J. Fadejev and J. Kurnitski - Parametric study for the long term energetic performance of geothermal energy piles
Example: 200 W/m, 6m spacing, L=30m,
Heat pump evaporator sized at ca 215 kW.
TALLINN UNIVERSITY OF TECHNOLOGY
A. Ferrantelli, J. Fadejev and J. Kurnitski - Parametric study for the long term energetic performance of geothermal energy piles
(Blank column: oversized system)
Initial heat
pump
evaporator
Power
[W/m]
TALLINN UNIVERSITY OF TECHNOLOGY
GEOTHERMAL PLANT SIZING GUIDE
1) Determine building design heat load and annual
heating energy need: design heat load (design
temperature -26°C) Q = 360 kW, annual energy need
E183 MWh).
2) Size the heat pump evaporator: 180 kW for heat
pump condenser, evaporator as Qevap = 140 kW.
3) Estimate total pile field length and condenser yield:
assume 30m long piles, then simulation results give
the specific yield per unit length E/L [kWh/m].
For 60 W/m we obtain 103 MWh for 6m pile step.
103 MWh<168 MWh (demand) -> more piles or
thermal storage.
A. Ferrantelli, J. Fadejev and J. Kurnitski - Parametric study for the long term energetic performance of geothermal energy piles
TALLINN UNIVERSITY OF TECHNOLOGY
CONCLUSIONS AND PERSPECTIVES
CONCLUSIONS:
Simulations combining heat transfer in
the soil with pumping system above.
Period of 20 years, commercial hall-
type building in cold climates.
Piles length,spacing and performance.
Shorter piles are more performing.
Smaller initial extraction power.
Preliminary sizing of the GHE system.
PERSPECTIVES:
Extend to other buildings and climates.
Thermal storage!
More soil types with stratification.
Validation with measurements.
Theoretical cross check of results.
ALL OF THE ABOVE IS WORK IN PROGRESS
A. Ferrantelli, J. Fadejev and J. Kurnitski - Parametric study for the long term energetic performance of geothermal energy piles
DD.MM.YYYY
THANK YOU FOR YOUR ATTENTION!
Andrea Ferrantelli
Department of Civil Engineering and Architecture
Tallinn University of Technology
07.11.2019
1st Nordic ZEB+, Trondheim
ResearchGate has not been able to resolve any citations for this publication.
ResearchGate has not been able to resolve any references for this publication.