Geothermal Energy for the Renewable Energy House

Transcription

1 European Geothermal Energy Council Geothermal Energy for the Renewable Energy House Presentation for the Workshop on the Inauguration day, Dr. Burkhard Sanner President, EGEC

2 Geothermal Energy Definition: Geothermal Energy is energy stored in the form of heat beneath the surface of the solid earth Graph from Geothermal Education Office, California

3 Geothermal Energy Geothermal energy applications comprise: electric power production, mainly from high temperature resources in Italy, Iceland, etc., but meanwhile also from regions with lower geothermal temperature e.g. in Austria and Germany; district heating with geothermal energy is popular in geological basins; the applications include, beside district heat supply, greenhouse heating, agricultural drying processes, and industrial process heat. a large number of small, de-centralised geothermal heat pump systems for heating (and cooling) of individual houses, office buildings, etc.,

4 Shallow Geothermal Energy for Heat and Cold The various shallow geothermal methods horizontal loops m depth borehole heat exchangers m depth (vertical loops, BHE) energy piles 8-45 m depth ground water wells 4-50 m depth water from mines and tunnels Rohre in Graben Verteiler im Haus Grundwasserspiegel Pumpe Serienschaltung BHE Groundwater wells

5 Shallow Geothermal Energy for Heat and Cold Wärmepumpe Heizung Niederdruck Hochdruck Kompressor Motor Schematic of a geothermal heat pump (ground source heat pump) Verdampfer Expansionsventil Verflüssiger

6 Geothermal System for the Renewable Energy House Schematic of system operation Summer (cooling) winter (heating) chaleur solaire système de refroidissement d absorption rejets de chaleur dans la terre chauffage du bâtiment extraction du chaleur de la terre pompe à chaleur electrique 230 / 400 V ventilation du bâtiment 4 sondes terrestres à 115 m 4 sondes terrestres à 115 m

7 Geothermal System for the Renewable Energy House The maximum heat load is 25 kw, the expected monthly distribution can be seen in the figure. The maximum supply temperature 8,0 should be in the 7,0 order of C 6,0 (modern radiators 5,0 with large surface) MWh/month 4,0 3,0 2,0 1,0 0,0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 01-31

8 Geothermal System for the Renewable Energy House In addition to the heating in winter, the ground system is intended to work for the re-cooling of the solar absorption cooling system The solar cooling system brings rather high heat loads, but for short time only. kwh/month cooling demand condensor heat partly condensor heat fully 0 Mai Jun Jul Aug Sep cooling demand and heat to be re-cooled

9 Geothermal System for the Renewable Energy House Feasibility study and design: For the underground, an average situation with a mean thermal conductivity of 2.0 W/m/K is considered. For calculation of the number and depth of BHE, the software EED was used, jointly developed by the universities in Giessen/Germany and Lund/Sweden. The typical temperature goal in the BHE (according to VDI 4640) can be achieved with 4 BHE each 115 m deep (total 460 m). Due to the high flow volume in summer operation, the BHE need to have a 40 mm diameter

10 Geothermal System for the Renewable Energy House Fluid temperature [ºC] Base load Peak cool load Peak heat load Results of EEDcalculation 0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Year 25 Temperature development in the ground after 25 years Min-max temperature development in the ground over 25 years Annual min-max fluid temp. [ºC] Year Peak min Peak max Base min Base max

11 Construction of the Geothermal System Drilling at REH on The rig had to pass this corridor

12 Construction of the Geothermal System Location of BHE, trenches and manifold Foot of BHE from HAKA.GERODUR

13 Construction of the Geothermal System The manifold outside the heat pump room Finished BHE and trenches

14 Heat pump for the geothermal system The heat pump is from Ochsner company, Austria. According to the heat load of the rear building (25 kw) the heat pump data are: Type: Ochsner Golf GMSW 38 Heat output: 28,3 kw electr. consumption: 6,4 kw refrigerant: R 407C

15 EGEC wants to thank the sponsors who helped to make the geothermal system a reality!