Abstract: Taking the refinery steam power system of W petrochemical company as an example, this study starts from the current configuration of the system to analyze its characteristics and main existing problems. The results indicate that the proportion of process steam generation from a single fluid catalytic cracking（FCC） unit within the steam power system is excessively high. Under abnormal operating conditions, this leads to significant safety hazards, including an excessive steam supply deficit and an unacceptably high steam release rate in production units.Furthermore, a dynamic mathematical model of the steam power system was established using the fluid continuity equation and the gas state equation. Using the safety interlock of the main air blower in the FCC unit as the initial condition for abnormal operation, simulations were performed. The calculations show that under the premise of purchased steam ramping up from minimum load to full load within 10 minutes, a low-pressure (LP) steam release rate of 40% is required to maintain basic stability in the pressure of both the medium-pressure (MP) and LP steam networks.Based on this, three alternative solutions were compared: increasing purchased MP steam, increasing purchased LP steam, and constructing an in-house emergency boiler. The results demonstrate that building a new emergency boiler has the lowest operating cost and is independent of external conditions (such as the operational status of the cogeneration plant), making it the preferred emergency measure.After the new emergency boiler was commissioned, optimized emergency response management reduced the ramp-up time for purchased steam and emergency boiler steam generation from minimum to full load from 10 minutes to 5 minutes. The steam release rate decreased from 40% to 20%, significantly mitigating the impact of abnormal operating conditions on the production process.

Key words: refinery, steam power system, abnormal operating condition, dynamic simulation, steam release rate, emergency measures