For the analysis of thermodynamic processes in tanks, the propellant tank analysis engineering S/W COMPTAS was developed. It runs with the dynamic modeling and simulation tool EcosimPro under WINDOWS NT or XP on a PC.
The processes analyzed cover liquid filling/depletion, gas pressurization/venting, evaporation from the liquid phase, condensation from the ullage gas/vapor mixture, dissolution/de-solution of pressurant in the liquid, thermal exchange among the fluid layers and between fluids and the tank wall structure, and thermal exchange with the environment through the tank wall insulation.
The tank is coded as object in EL (EcosimPro language) with fluid- and thermal ports, which can be connected to the ports of other objects like pipes, fluid supply, etc., defined also with their functional characteristic in a set of appropriate algebraic equations. All components and functions are comprised in a dedicated COMPTAS S/W library.
Subject of this paper is the presentation of the COMPTAS modeling approach, the S/W design and a demonstration of the functional performance for a sample case using LN2 and GN2.