mi.ttu.ee

Veiko Karu

veiko.karu@ttu.ee

Tallinn University of Technology

Department of Mining

Estonian Mine Water Heat Pump Project

Experiences

mi.ttu.ee

Presentation outline

• Study area

• Mining technology and water amounts

• Heat pump in Kiikla

• Potential solutions

• Summary

2

mi.ttu.ee

Location

3

mi.ttu.ee

Estonian oil shale bed

4

mi.ttu.ee

Middle part of deposit

5

mi.ttu.ee

Objects of the study

6

mi.ttu.ee

7

- 2 0

- 1 0

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

0 5 0 0 0 1 0 0 0 0 1 5 0 0 0 2 0 0 0 0 2 5 0 0 0

E s t o n ia n o i l s h a le d e p o s i tC r o s s s e c t i o n f r o m n o r t h t o s o u t h

Ab

s

alt

itu

de

,

m

L e n g t h , m

Cross section of oil shale bed

mi.ttu.ee

Oil shale seam

• Mining methods

–Hand mining

–Longwall mining

–Room and pillar

mining

8

Lithology Layer Layer

thickness,

m

Height from

layer A, m

F2 0.30 3.03

F1 0.34 2.73

E 0.59 2.39

D/E 0.10 1.80

D 0.07 1.70

C/D 0.29 1.63

C 0.45 1.34

B/C 0.08 0.89

B 0.37 0.81

A/B 0.21 0.44

A 0.23 0.23

mi.ttu.ee

Study area and data collection

• Mining methods

• Classification of

undermined areas

• Groundwater

• Rock parameters

• Geometrical properties of

the waterbody

• Hydrogeology calconditions

• Minewater as heat source

9

mi.ttu.ee

Closed mines in study area

10

Options Kukruse Mine no 2 Käva Käva 2 Mine no 4 Tammiku Sompa Kohtla Ahtme

Mine opening 1921 1949 1924 1924 1953 1951 1948 1937 1948

Mine closing 1967 1973 1972 1972 1975 1999 1999 2001 2001

Working time, year 46 24 48 48 22 48 51 64 53

Field area, km2 13,20 12,30 3,47 14,05 12,70 40,00 33,60 18,30 43,30

Mined field area, km2 15,13 8,57 1,84 11,72 10,43 19,26 18,14 12,14 26,36

Not mined area, km2 -1,93 3,73 1,63 2,33 2,27 20,74 15,46 6,16 16,94

Thickness of

overburden, m

11 13 21 10 12 23 23 15 37

Thickness of oil shale

seam, m

2,83 2,81 2,83 2,82 2,8 2,8 2,77 2,76 2,79

Geological space in oil

shale seam, mln m3

42,82 24,08 5,22 33,05 29,20 53,92 50,24 33,52 73,53

mi.ttu.ee

Hand mined method areas

11

mi.ttu.ee

Hand mined method

12

mi.ttu.ee

Room and pillar mining

13

mi.ttu.ee

Room and pillar mining

14

mi.ttu.ee

Free space in underground

15

Geology Mining method and mineral extraction (m)

A

A'

B/A'

B

C/B

C

D/C

DE/D

E

F1

F2

F3

G/F3

G-H

layers

A/A'

Longwall

face

Hand-mined

Room and pillar

(low roof)

Room and pillar

(high roof)

Limestone

Oil shale layers Limestone layers

Oil Shale seam

Oil

shale

seam

L

ime

-

sto

ne

mi.ttu.ee

Used mining methods

16

Mined area

• Hand-mined

– 70.75 km2

• Longwall

– 14.10 km2

• Room and pillar

– 133.60 km2

mi.ttu.ee

Classification of undermined areas

-Steady land -Subsided land -Stable land -Quasistable land

Photo: Estonian Land Board; LIDAR

17

mi.ttu.ee

Underminined areas stability

18

mi.ttu.ee

Spatial models (1/2)

19

• Layer interpolation

• Grid calculations

• Cross-sections

• Layer properties

• Layer volumes

mi.ttu.ee

Spatial models (2/2)

20

• 3D model

• Hydrogeology

modelling

• Water flow

• Water volumes

• Pumping test

mi.ttu.ee

Parameters for modeling

21

mi.ttu.ee

Spatial modeling

Surface Oil shale seam bottom

22

mi.ttu.ee

ModFlow model

23

mi.ttu.ee

ModFlow oil shale seam

24

mi.ttu.ee

Water in closed mines

25

mi.ttu.ee

Out flow areas

Ahtme mine

Sanniku stream

Tammiku mine

Rausvere stream

26

mi.ttu.ee

Water amounts

27

mi.ttu.ee

Water amount in mines

28

mi.ttu.ee

Mine water amount distribution

29

mi.ttu.ee

Water requirments

30

Heat

requirement,

MW

Change in

temperature

, OC

Initial water

temperature, O

C

Final water

temperature

after heat

pump, O

C

Water

requirements,

m3/h

10 1 8 7 8 604

10 2 8 6 4 302

10 3 8 5 2 868

10 4 8 4 2 151

50 1 8 7 43 021

50 2 8 6 21 511

50 3 8 5 14 340

50 4 8 4 10 755

mi.ttu.ee

Pumps parameters

31

Pumping station

Producer Pleuger pumps Unit

Capacity 1200 m3/h

Head 34 m

Motoroutput 165 kW

Heat pump station

Producer Acwell Unit

Heating capacity 1536 kW

Power input 366 kW

mi.ttu.ee

Potential locations

32

mi.ttu.ee

Pumping test Ahtme

33

Pumping and filling 42 000 m3/h

mi.ttu.ee

Technological solution

• Using minewater in heat pumps, the best

possible technical solution in Ahtme is:

– pumping the water through drillhole onto the

ground surface

– water goes to heat exchanger unit

– minewater temperature will be lowered in

heat pump heat exchanger about 1...4

degrees,

– after that minewater is directed back to the

mine.

34

mi.ttu.ee

Pilot project in Kiikla

35

mi.ttu.ee

Pilot project in Kiikla

mi.ttu.ee

Heat pump in Kiikla

Heat exchanger Heat pump

37

mi.ttu.ee

Technological solution in Kiikla

38

mi.ttu.ee

Heat pump work

39 Water from

Oil Shale mine

Heat pump

Photo: The Energy Groove

Consumer

mi.ttu.ee

Kiikla 500kW heat pump

40

Have been working three years

mi.ttu.ee

Ideas for heat pump locations

• Heat pump complex to

– Viru mine

– Aidu open cast

• Heat pump in Kose settlement

41

mi.ttu.ee

SUMMARY 42

mi.ttu.ee

Spatial dynamic method

• Spatial models

• Hydrogeological

model

• Stability models

43

mi.ttu.ee

Minewater as heat source for

heat pumps

• Water amount

• Technological

solutions

• Mine closure

44

Photo: Postimees.ee

mi.ttu.ee

Conclusion

• Potential location in Ahtme

• Water requirments for heat pump

complex

• Technological solutions for using mine

water as a heat source

• Pilot project in Kiikla settlement

• Future mine closure ideas

mi.ttu.ee

Thank You!

Veiko Karu TUT Mining Department

veiko.karu@ttu.ee

http://mi.ttu.ee

Estonia