Objectives  In the process of the emergency deceleration and reversing operations of marine steam power systems, back-steam control technology is an effective means of alleviating the problem of boiler drum overpressure, so it is necessary to study its influence on the system.

  Methods  This paper establishes a steam power system simulation model of a supercharged boiler, main steam turbine and propeller, and carries out the simulation and comparative analysis of the characteristics of back-steam control in the process of the emergency deceleration and reversing of large ships under the three working conditions of quick closing valve with/without back-steam and slow closing valve without back-steam.

  Results  The simulation results show that the steam return control technology can effectively prevent boiler drum overpressure in the process of emergency deceleration and reversing, and the system stability time is shortened by about 3 mins and 1 min respectively.

  Conclusion  The results of this study can provide references for ship maneuverability and safety design.