Тема: Control System and Instrumented Protective Functions
for Fired Equipment- System for a single-burner furnace

контексты:
Anti reset wind up (ARWU) protection shall be implemented on the master temperature controller TRC 1 and the oxygen controller QRCA 1.

If the chosen DCS / Controller algorithm supports the use of external feedback as ARWU protection, then external feedback can be configured from Y10 to QRCA. This external feedback improves the response of the oxygen QRCA during changes in load of the furnace. The principle behind this external feedback is as follows:
If the load of the furnace is reduced and the airflow is reacting more slowly than the fuel flow (due to parallel lead / lag control configuration), the external feed back ensures a minimum overshoot. If there were no external feedback, the QRCA would react to the excess air and further reduce the air, thereby resulting in an overshoot when approaching the final steady state value.
If the control scheme is implemented in a DCS which does not support external feedback (i.e. only ARWU is used), the QRCA should be tuned to slow response to minimise the overshoot during transients.