Method and Heat Exchange System Utilizing Variable Partial Bypass

摘要

Temperature overshoot of internal components of a counter-flow shell and tube heat heat exchange may be reduced or avoided by adjusting the degree to which a tube-side fluid partially bypasses the heat exchanger.

主权项

1. A method for reducing overheating of internal components of a counter-flow shell and tube heat exchanger utilizing variable partial bypass of a reactant flow, said method comprising the steps of:
dividing a first feed flow (FF1) of a cool reactant with a first control valve (CV1) between a first main flow (MF1) of the cool reactant and a first bypass flow (BF1) of the cool reactant, the first main flow (MF1) flowing through a counter-flow shell and tube heat exchanger on a tube-side of the heat exchanger; exchanging heat at the shell and tube heat exchanger between the first main flow (MF1) and a flow of a hot shell-side fluid and combining the first main flow (MF1) with the first bypass flow (BF1) to produce a first combined flow (CF1) of heated reactant and also a flow of cooled shell-side fluid, the first combined flow (CF1) exiting the heat exchanger at a first reactant outlet (RO1) of the heat exchanger; measuring a temperature of the first combined flow (CF1) at or downstream of the first reactant outlet (RO1); and controlling relative proportions of the first main flow (MF1) and first bypass flow (BF1), resulting from division of the first feed flow (FF1), with the control valve (CV1) based upon the measured temperature of the first combined flow (CF1), wherein less heat is transferred from the shell-side fluid to the first bypass flow (BF1) than is transferred from the shell-side fluid to the first main flow (MF1).