Thermochemical module

Thermochemical module predicts internal temperature in the structure and tooling and the resin degree of cure in composite structural components. 

The boundary conditions that may be used with the thermochemical module include specified boundary temperature, convective heat transfer or no heat transfer (adiabatic). Different conditions (e.g., different HTCs) can be applied to each element as desired. Either explicit or implicit techniques may be chosen to solve the heat transfer (Eq. [13.1]) and cure rate equations. Using either technique, these two equations are uncoupled during each solution time-step. This approach facilitates a simplified and modular solution procedure and is sufficiently accurate if small time steps are used. 

Figure 253. Thermochemical storage system (Humidifier, water tank and control unit in the front from left to right, three Zeolite modules in the back)...

The above thermochemical values were used to fill the heterogeneous module of the kinetic scheme for the OCM reaction over a model Li/MgO catalyst with corresponding kinetic parameters (see Table III). In combination with a scheme of homogeneous methane oxidation, this set of reactions forms the desired micro-kinetic description. It allowed us to re-consider specific features of the OCM process and to obtain some unexpected results. 

The saturation index module would be the location for additional enhancements to the system to make it applicable to waters from formations of more complex mineralogy, to include uncertainty in the thermochemical data used, and perhaps to consider mineral reaction rates and water residence times. The direction of such enhancements are sketched below. 

The present saturation index module considers only minerals common in carbonate aquifers and assumes that water residence times are sufficient to assure mineral-water equilibria. The next step might consider geothermal systems of simple mineralogy. For this step the expert system might include various chemical geothermometers as indicators of analytical reliability. While high temperatures would promote the attainment of mineral-water equilibria, they would also add to the uncertainty in the thermochemical data used for modeling those equilibria. 

FactSage, with its modules to manipulate thermochemical databases and to calculate complex equilibrium states as well as multi-component phase diagrams, has been applied for the data compilation and assessment work described below as well as for the generation of the graphical results presented further below. 

Before complex thermodynamic models including explicit kinetics (here the diffusional transport of reactive elementary or molecular species) are employed, it is most useful to obtain, with the aid of classical thermochemical calculations, a picture of the momentary situation, i.e. of the frozen-in state at a certain moment in time. For that purpose the databank system FactSage provides two modules which are particidarly suited Equilib and Phase Diagram. 

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