Can TOUGH3 model temperature below zero degree?
I am new to TOUGH and plan to use it in modeling a borehole thermal energy storage system. However, the ground temperature surrounding the system may drop to below zero degree. I wonder if TOUGH3 can handle this issue?
Thanks in advance,
As reminded by Christine, TOUGH2/3 cannot handle T below the triple point of water, as 0.01°C is the lower limit for the old IFC67 and the new IAPWS-IF97 correlations for the properties of water and steam.
Simulations with negative T were made with TMGAS (Battistelli and Marcolini, 2009), a special version of TMVOC (Pruess and Battistelli, 2002) for real mixtures of gases (inorganic gases and hydrocarbons) in equilibrium with a sodium chloride brine. Elements in single-gas conditions with an NCG mixture can actually go below 0°C, with gas phase properties computed with a cubic EOS for real gases. Few modifications were made to avoid the run stop due to calls to water & steam routines below 0°C.
This was used to simulate the injection of acid gas mixtures that in some specific WH injection conditions may have T below 0°C. The figure below shows the wellbore injection profiles at different injection times of an acid gas mixture with T below 0°C in the first 1000-1500 m. Single gas conditions with no water vapor were assigned to the rock formations in contact with the upper wellbore section to simulate negative temperatures even in the rock formation.
Negative temperatures along a wellbore can also be simulated with T2Well-ECO2M (by Lehua Pan) in case of mixtures of H2O-CO2-NaCl. An example is given by Strpić et al. (2020) Evaluation of time-convolution approach for modelling heat exchange between wellbore and formation during multiphase CO2 injection with T2WELL-ECO2M, OMC 2021.