Heat calculation unit in the mathematical model of air separation plant evaporator-condenser

The thermal calculation, which is part of the mathematical model of a condenser-evaporator of cryogenic air separation plants, is considered. The calculation is based on solving the criteria equations of heat exchange for cases of condensation outside of the pipe and evaporation inside the pipe. The thermal calculation is preceded by a hydraulic calculation, the results of which are used as input quantities. The solution is carried out by a multistep (iterative) method. The heat flow density on the evaporation side is used as a criterion for convergence of iterations. The calculation scheme, divided into successive steps, is shown. The calculation results are used to determine the geometric configuration and the main characteristics of the condenser-evaporator.