WP 2.4
The storage of heat in the underground will influence parameters of groundwater flow and transport of dissolved compounds. Therefore, storage of heat in aquifers may result in changes of large scale groundwater flow and transport regimes. Reduction of water density and viscosity, e.g. may alter local hydraulic conductivities of an aquifer; an increase of thermal movement of dissolved compungs with temperature will result in increased diffusive spreading. Based ob published data on these temperature influences, the simulator OpenGeoSys (OGS) will be extended for these dependencies and parameterisations for flow and transport processes. Subsurface heat storage and the resulting substantial temperature changes may also affect the geomechanical behaviour of soils. In cooperation with the experimental studies of WP 1.6 therefore a parametrisation of these temperature dependend parameters based on the critical-state model (CamClay-model) will be achieved and implemented in OGS. For a prognosis of the influences of heat storage on the behaviour of aquifers contaminated by organic contaminants also an extension of so far only isothermal reaktive process models in OGS for the temperature dependencies of geochemical equilibrium constants, solubilities and dissolution kinetics of contaminants and DOC, microbial growth and degradation rates, etc., is required. These extensions of the code are be based on published literature data and results of the experimental studies in WP 1.8. Verification and benchmarking oft he new methods will be achieved by test simulations against analytical solutions and other codes, as well as by comparison against experimental data of WP 1.8.
The working group geohydromodelling is working on WP 2.4. The implementation of the temperature dependencies of geomechanical behaviour of soils as well as the geochemical reactions requires the identification and quantification of these dependensies in the experimental work of WP 1.6, WP 1.8 and WP 1.9. These studies also serve for the verification of the THMC code, which then will be used for numerical simulations of heat storage scenarios in WP 3.4.
