Reuse of industrial waste heat by borehole thermal energy

Geoenergi 2015 in Bergen, September 2‐3
Reuse of industrial waste heat by borehole thermal energy storage, Emmaboda Sweden Presented by Olof Andersson, Geostrata The Xylem Industry, Emmaboda HT‐BTES
Emmaboda
The old workshop Now a museum
The world leading manufacturer of pumps and mixers (Flygt) Approx. 110 000 m2 of space heating floor area
The initial concept
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Seasonal storage of surplus waste heat
From summer to winter Load capacity, 1000 kW Storage capacity, 3‐4 GWh
Working temp. 40‐60oC
140 holes á 150 m were drilled (winter 2009‐2010)  It took 11 weeks for 2‐3 rigs at site. Tuff conditions due to harsh winter conditions
 Problems with fracture zones and, hence, extensive grouting work delayed the work
Special designed BHE were installed
The BHE
A double tube coaxial insulated BHE type that allows a direct contact with the borehole wall with ground water as a heat carrier
Boreholes connected summer 2010
Connected into 7 sections in parallel
BTES area: 60x40 m
Connection pipes DN 40
Field manifolds
DN110 Main pipes
DN 90
Storage insulation (autumn 2010)
Layers from top to bottom
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Organic soil, 30 cm
Geotextile
Foam glass, 40 cm
Geotextile
Sand, 20 cm
Pipe system, 5 cm
Sand 20 cm
Not visable today
Flow chart
Storage
Internal heating system
Connection pipe
Max +55
The system flowchart
Heat sources (Connected stepwise since 2010)
Heat Sources
H/C HP Foundry
HX Owen Foundry
H/C HP Paint shop H/C HP Server Halls 1‐2
H/C HP UPS (Battery Backup)
H/C HP Server Halls 3
H/C HP Evaporator
H/C HP Compressor Central
HX Compressor 1
HX Compressor 2
H/C HP Testing 2
H/C HP Curing oven
HX Compressor Central
Power
(kW)
Available Annual Energy (MWh)
Max Temp.
(°C)
550
450
150
90
15
60
20
170
120
90
80
90
100
3000
1000
400
500
80
400
50
1200
700
350
200
450
100
60
65
70
70
65
70
65
70
90
90
70
70
90
Sum 1985*
8430
*/ The heat powers are not all available at the same time. H/C HP = heating/cooling heat pump. HX = heat exchanger.
Approx. 10 000 MWh stored 50% less than planed
Stored
Recovered
Development of storage temperature
The temperature development over the four years of operation
(The initial rock temperature was +8 °C)
The storage configuration and the temperature monitoring boreholes
Saving of district heat
Bought external heat (GWh)
8
7
Enhanced recovery + HT‐BTES
6
5
Fully developed
4
3
2
1
0
2010
2011
2012
2013
2014
Conclusions
• The initial plan to have a storage working temperature at 60‐40oC is not applicable (max temp. after HEX is 55 oC)
• To enlarge the benefit of storage a heat pump should be installed – and a lower storage temperature (45‐25 oC ) should be applied
• Such a concept would also decrease the heat losses as well as optimize the efficiency of waste heat catchment Expected future energy cost flowchart Waste Heat Sources
120 SEK/MWh
8 000 MWh potential
(COP 4,2)
Free cooling
(Bonus)
Cost of utilized heat after storage
‐ To storage, 120 SEK/MWh ‐ From storage, 145 SEK/MWh ‐ After heat pump, 225 SEK/MWh
To compare
‐ Bought heat, 700 SEK/MWh
(Electricity, 500 SEK/MWh)
Excess heat for storage
Space heating system
3 600 MWh
COP 6,0
HP
3 800 MWh
3 000 MWh
Losses
800 MWh
Borehole storage (45‐25 oC)
Thanks for Your attention!
Fore more information, please contact:
Olof Andersson: [email protected] (designer)
or
Leif Rydell: [email protected] (operator)