Simscene Focus: Heat Exchanger Simulation
Concentration Heat And Momentum Limited (CHAM) – a long-established consultancy controlled by world-renowned scientist Professor D Brian Spalding FRS – develops and
applies its PHOENICS Computational Fluid Dynamics (CFD) software to a range of processes involving fluid flow, heat and mass transfer, chemical reaction and combustion.
CHAM has developed a low-cost, easy-to-operate CFD-based simulator for shell-and-tube heat exchangers, called HeatEx, that embodies the best available computer models
of all the features which conventional industry-standard design packages either ignore or guess, including:
◊ realistic flow patterns within baffled tube banks and headers;
◊ non-uniformity of tube-and shell-side heat-transfer and pressure-drop coefficients;
◊ temperature dependence of fluid properties; and
◊ start-up and shut-down behaviour.
HeatEx simulates the thermal performance of three-dimensional shell and tube heat exchangers, providing a pragmatic aid for designers and manufacturers to develop moreefficient and cost-effective heat exchangers.
HeatEx can handle all the usual TEMA (Tubular Exchanger Manufacturers Association) flow configurations, with arbitrary numbers and shapes of baffles, number of tube-side passes, etc. It predicts
the overall effectiveness and pumping-power requirements and reveals the internal flow distributions, locations of maximum tendency to tube vibration, low-velocity locations where deposits may
occur. All the things which operators truly want to know.
HeatEx employs a computationally-economical “space-averaged” CFD technique to permit designs to be modelled using portable computers, and enable the heat-transfer behaviour of the entire
heat exchanger to be predicted swiftly and accurately. It overcomes most of the limitations of the manual and numerical methods currently used to rate heat exchanger performance, by removing
simplifying assumptions, such as:
◊ uniformity of fluid properties;
◊ uniformity of heat-transfer coefficient; and
◊ independence of time.
HeatEx offers a choice of TEMA shell types in
addition to the default “E-type.”
The fluids occupy the same region separated by the m WF