Load Rejection Capability for Large Steam Generators

This paper is tutorial in nature and deals with the ability of the large utility steam generator to reject load in response to turbine interaction with system requirements, such as would occur if the system sustained an instability or a disturbance. The transient mismatch of system requirements with the output generation of the steam generator/turbine unit imposes a difficult transient operation on the steam generator. Necessary provisions to sustain partial load rejections, which are defined to cover the range from short term implementation of fast valving to complete separation of the main load, are outlined. Also typical steam generator response to load rejection is defined from both analytic investigation and test results.