Numerical modelling of a parallel flow heat exchanger with two-phase heat transfer process

摘要

In this analysis a 1-D steady state heat transfer was accomplished for tube and shell type heat exchanger with parallel flow configuration. Molten salt was regarded as a secondary flow that runs in the shell part of the heat exchanger whereas the saturated water was regarded as the primary flow that flows in the tube part of heat exchanger. The analysis is done for 0.1 kg/s mass flow rate of the primary flow and for various mass flow rate of the secondary flow ranging from 0.1 kg/s to 0.6 kg/s. The heat exchanger's thermal characteristics, such as, variation in steam quality and two-phase convective coefficient of the saturated water alongside the length of the tube are collected from the analysis. In addition, temperature profiles for primary and secondary flows are presented in this article. It is found that for the considered geometry of the heat exchanger and the boundary conditions, a 0.376 kg/s mass flow rate of molten salt is required to convert the 0.1 kg/s mass flow rate of primary flow into saturated steam. As a result, a mass flow rate of molten salt which is greater than 0.376 kg/s is required to super heat the primary fluid (water).