By Richard Grant, President, Grantec Engineering Consultants Inc., Halifax, Canada
Because of the potential for high operational pressures and the consequences of failure (which could include personal injury, equipment loss, and/or decreased output and revenue), shell-and-tube heat exchangers are classified as pressure vessels. Pressure vessels are strictly regulated in North America and elsewhere in the world. To commission a new design requires regulatory approval. Heat exchangers with symmetric tube layouts can typically be assessed using codes such as the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC). However, for exchangers with highly asymmetric tube layouts, simulation is often the only cost-effective way to qualify these designs. Ansys Mechanical software was recently used by Grantec Engineering to perform finite element analysis (FEA)-based strength assessments for a range of condenser and evaporator heat exchangers to gain rapid approval from regulatory authorities.