(373a) Simulating Relief Scenarios in a Column Using Aspen Hsys

Simulating relief scenarios for a column is complex and involves multiple variables. The column is simulated at relief pressure. The reboiler duty can be kept constant, or credit can be taken for temperature pinch. The feed temperature needs to be either adjusted to relief pressure or kept same at operating point depending on column feed preheat arrangement. A credit due to reboiler piping can be taken to reduce an effective duty from the reboiler. The overhead condensers / coolers will lose its surface area due to flooding from losing overhead pump. In Reflux failure scenario, heat removal by boiling the reflux liquid is lost, more vapor to condenser resulting in overpressure and relief situation. During loss of feed scenario, the additional vapors generated exceed the capacity of condenser to condense, pressure will go up and relief would occur.