Sorry if this has been posted before, but the search function was not working when I tried.
I am sizing a relief valve for a distillation column (unbalanced heat method), and my relief load calculations are based on the relieving conditions (1.1*Pset). This column handles many different components in varying concentrations depending on the batch. One case reaches the critical point nearly halfway between set pressure & relieving pressure, and appears to be the largest load based on calculations at the set pressure.
My experience with fluids at or above critical points is very limited, though my understanding is this: Once the critical point is reached, the boiling ceases, and relief load is effectively a result of expansion due to temperature increase as if the column only contained vapor. This expansion results in a much lower relief load than the vapor generation due to boiling based on my preliminary calculations.
I have calculated the maximum relief load by varying pressure incrementally between the set pressure and relieving conditions. Should the relief load be based on this maximum vapor generation rate between the setpoint and the relieving conditions as I calculated? If there is any printed guidance on cases like this, please let me know.
Thanks!