Transcript WORK PLANS

Building Services Engineering
CHALMERS
OPTIMIZATION OF
GROUND COUPLED HEAT
PUMP SYSTEMS
Saqib Javed (PhD Researcher)
Per Fahlén (Research Leader)
Johan Claesson (Supervisor)
EFFSYS 2 meeting 2009-12-14
Akademiska Hus
Carrier
CTC / Enertech
Donghua University
Fastighetsägarna
Geotec
Grundfos
IVT
LTH
NCC
Nibe
SWECO
TAC
Thermia Värme
Wilo
ÅF-Infrastruktur
Building Services Engineering
CHALMERS
OBJECTIVE
• Identifying key optimization factors for Ground Coupled Heat
Pump (GCHP) systems using modelling, simulations field
studies and experiments.
• Developing simple and user-friendly models and calculation
tools to facilitate designers and researchers interested in the
complete system optimization.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
LITERATURE REVIEW
• Single boreholes: Long term response can be modelled using
simple existing analytical models with reasonable accuracy.
• Multiple boreholes: Shortage of analytical models for both long
and short term response.
• Need of an analytical model which:
- is capable of simulating both short-term and long-term
response of GHE.
- considers all significant heat transfer processes in GHE.
- retains the actual geometry of the borehole.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
CASE STUDY
• Astronomy-House, Lund University
Month
 Floor area: 5300 m2
 Heating demand: 475 MWh
 Cooling demand: 155 MWh
• Ground system
 20 boreholes
 Rectangular configuration
 Each 200 m deep
EFFSYS 2 meeting 2009-12-14
Jan
Feb
Mar
Apr
May
Jun
July
Aug
Sep
Oct
Nov
Dec
Year
Qh
Qc
[MWh] [MWh]
97.9
89.3
69.8
40.9
20.9
31.4
47.5
77
475
3.4
7.3
15.0
25.7
33.2
31.3
19.2
13.3
6.4
155
Building Services Engineering
CHALMERS
SIMULATING MULTIPLE BOREHOLES
Tb = brine temperature
Tw = borehole wall temperature
Tp = temperature penalty from neighbouring boreholes
#
Borehole wall temp (Tw)
Temperature penalty (Tp)
1
Cylindrical Source
Infinite length line source
2
Cylindrical Source
Finite length line source
3
Infinite length line source
Infinite length line source
4
Finite length line source
Finite length line source
5
Superposition borehole model (SBM)
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
9
16
Maximum mean brine temperature →
7
15
14
5
13
3
12
11
1
10
-1
-3
9
← Minimum mean brine temperature
0
5
Year
10
8
15
CS (borehole interaction with infinite LS)
CS (borehole interaction with finite LS)
Infinite LS (borehole interaction with infinite LS)
Finite LS (borehole interaction with finite LS)
SBM
EFFSYS 2 meeting 2009-12-14
Maximum mean brine temperature [ºC]
Minimum mean brine temperature [ºC]
MEAN BRINE TEMPERATURES
Building Services Engineering
CHALMERS
PUBLICATIONS
•
Javed, S., Fahlén, P. and Holmberg, H., 2009. Modelling for optimization of brine
temperature in ground source heat pump systems. Proceedings of 8th international
conference on sustainable energy technologies; SET2009, Aachen, Germany. August
31- September 3.
•
Javed, S., Fahlén, P. and Claesson, J., 2009. Vertical ground heat exchangers: A
review of heat flow models. Proceedings of 11th international conference on thermal
energy storage; Effstock 2009, Stockholm, Sweden. June 14-17.
•
Fahlén, P, 2008. Efficiency aspects of heat pump systems - Load matching and
parasitic losses. IEA Heat pump centre Newsletter, vol. 26, nr. 3, 2008-08, (IEA.).
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
LITERATURE REVIEW
• Single boreholes: Long term response can be modelled using
simple existing analytical models with reasonable accuracy.
• Multiple boreholes: Shortage of analytical models for both long
and short term response.
• Need of an analytical model which:
- is capable of simulating both short-term and long-term
response of GHE.
- considers all significant heat transfer processes in GHE.
- retains the actual geometry of the borehole.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
MODELLING
• Existing Analytical models:
– Equivalent pipe / cylinder
instead of a U-tube.
– Thermal capacities of the
water and the pipe are often
ignored.
– Response is a function only
of the distance (r) from the
centre of the equivalent pipe.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
MODELLING
• New Analytical models:
– Two pipes in the ground.
– Accounts for the thermal
short circuiting between
the two legs of the U-tube.
– Response is a function of
both x and y.
– Can predict the short time
response accurately.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
MODELLING
• New Analytical models:
– Two pipes in the grout
surrounded by the ground.
– Accounts for the thermal
properties of both the grout
and the ground.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
MODELLING
• New Numerical model:
– Solved the heat transfer
problem in 2D using
conformal
coordinate
system.
– Used for the validation
of the analytical model.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
LITERATURE REVIEW
• Single boreholes: Long term response can be modelled using
simple existing analytical models with reasonable accuracy.
• Multiple boreholes: Shortage of analytical models for both long
and short term response.
• Need of an analytical model which:
- is capable of simulating both short-term and long-term
response of GHE.
- considers all significant heat transfer processes in GHE.
- retains the actual geometry of the borehole.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
EXPERIMENTS
• Development of a test facility.
• Experiments to determine:
–
–
–
Thermal response for heat extraction and injection conditions.
Flow effects.
System effects.
• Validation of the developed models.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
LABORATORY DEVELOPMENT
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
LABORATORY DEVELOPMENT
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
BRINE & CHILLED WATER SYSTEM
Borrhålslager
KMK1
GT-BH-1 -- 9
RV-BH1 till 9
P-BH1 till 9
GT-KMK1-2
DN50
EK-KB1-1
GT-BH-10 -- 19
AV-KB1-3
SÄV-EKKB1-1
GT-AT1-1
Toppen
AV-KB1-5
DN32
AV-VP1-1-2
GT-VP1-1-1
GT-VP1-1-2
P-KB1-1
GF-KB1-1
GT-KB1-1
GT-KB1-2
AT1
-10--+10 °C
AV-KMK1-2
AV-KMK1-1
P-VP1-1
+
DN32
GT-VVX- GT-AT2-1
KMK1-1
Toppen
P-KB2-1
VP1
AV-KB1-6
Botten
GT-AT1-2
AV-AT1-2-1 -- 3
GT-AT2-2
P-VP1-2
AV-VP1-2-1
DN32
GT-VP1-2-1
VP2
DN32
DN32
AV-KB1-1
P-KB1-2
AT2
+5--+15 °C
Botten
GT-KB1-3
AV-KB1-7
DN32
DN32
AV-KB1-2
DN32
VP2
VVX-KMK1
GT-VVXKMK1-2
DN50
EK-KB2-1
DN32
AV-VP1-1-1
AV-KB1-4
EP2
VV-KMK1-1
P-KMK1-1
GT-KMK1-1
DN32
AV-VP1-2-2
GT-VP1-2-2
P-KB2-2
DN32
DN32
KB2 processkylvatten
KB1 processköldbärare
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
HOT WATER SYSTEM
VVX-KMK2 P-KMK2-1
AV-AT3-2
P-VP3-1
SÄV-EK-VB1-1
AV-AT4-2
AV-AT3-3
GT-AT3-1
DN40
Toppen
AT3
+30--+55 °C
VP3
VP2
Botten
GT-AT3-2
P-VP2-2
P-VP3-2
AV-VP2-2-2
AV-VP2-2-1
DN40
GT-VP3-2-1
AT2
KB2-tank
DN40
AV-VP3-2-2 AV-AT3-1
BV-VP2-2-1
DN32 AV-VP3-2-1
GT-VP3-2-2
DN32
DN32
VV-VB1-2 P-VB1-2
AV-AT4-3
GT-AT4-1
SÄV-EK-VB1-2
GT-VB1-2
Toppen
GT-VB1-3
AT4
+30--+55 °C
DN32
Botten
GT-AT4-2
DN32
DN32
VB2
AV-AT4-1
DN40
AV-VP3-1-1
P-VP2-1
P-VB1-3
EK-VB1-2
VV-VP3-1
DN40
DN40
BV-VP3-2-1
GT-VP3-2-2
DN40
GT-VB1-1
VB1 värmesystem
VB1 processvärmevatten
EFFSYS 2 meeting 2009-12-14
Retur
AV-VP2-1-1
DN32
AV-VP3-1-2 GT-VP3-1-1
Fram
DN32
GT-VP3-1-2
P-VB1-1
Retur
AV-VP2-1-2
EK-VB1-1
Fram
GT-VP2-1-1
AV-KMK2-2
VV-VB1-1
AV-VB1-1
AT2
KB2-tank
AV-KMK2-1
VV-VP2-1
DN32
processvärme +20--+50 °C
GT-VP2-1-2
Building Services Engineering
CHALMERS
GROUND HEAT EXCHANGER SYSTEM
BH-1
BH-2
4,0
3,9
0,1
4,0
4,1
BH-3
2,2
4,1
N
BH-4
BH-5
4,4
4,0
BH-6
4,0
4,0
BH-7
4,0
BH-8
4,7
2,0
3,9
BH-9
Laboratory Building
2,1
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
THERMAL RESPONSE TESTING
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
INITIAL RESULTS
 Ground thermal
conductivity: 3 W/m-K
 Undisturbed ground
temperature: 9 °C
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
CONCLUSIONS
 Conducted a state-of-the-art literature review.
 Presented different approaches to model multiple
borehole systems.
 Developing new analytical and numerical methods.
 Carrying out experiments.
EFFSYS 2 meeting 2009-12-14
Building Services Engineering
CHALMERS
QUESTIONS / COMMENTS
THANK YOU!
EFFSYS 2 meeting 2009-12-14