Abstract: Malfunction under water-solid conditions responsive either to increase in mass flow or increase in heat flow into the reactor coolant is suppressed. The power-actuable reactor-coolant relief valve is opened for increase in reactor-coolant mass influx if the rate of change of coolant pressure exceeds a setpoint during a predetermined interval, if, during this interval, the coolant temperature is less than a setpoint and if the level of the fluid in the pressurizer is above a predetermined setpoint (water-solid state). The interval is set to preclude opening of the relief valve for transients.

Abstract: A combined cycle electric power plant includes two gas turbines, a steam turbine, and a digital control system with an analog or manual backup. Each of the gas turbines has an exhaust heat recovery steam generator connected to a common header from which the steam is supplied by one or both of the steam generators for operating the steam turbine. The digital/analog system includes a steam throttle pressure limiting control, which maintains a minimum steam throttle pressure as a function of steam flow to limit the maximum steam velocity through the steam generators, and reduce the probability of water carryover into the steam turbine. In response to a reduction in the number of steam generators in service, the pressure flow relationship is transferred from one characterization to another, and during such transfer, the analog system operates the steam turbine control valves to limit the rate of steam pressure decay as a function of steam flow.

Abstract: An electric power plant steam turbine system with digital computer control in which control signals are generated as a function of the actual steam conditions present in each turbine section and in a manner which maintains the sum of the instantaneous power developed in each turbine section equal to the total demand placed upon the turbine system.

Abstract: In a turbine system with first and second turbine stages, each having a bypass line thereacross, provision is made for utilizing only the valving of the first turbine stages to control the acceleration of the shaft driven by the turbine system from start-up to synchronous speed. At the same time, provision is made for diverting enough of the flow to the second turbine stages to meet the requirements of those stages.

Abstract: The stages of a turbine system are independently controlled to produce a desired system power output by monitoring and comparing the power characteristics of each stage to the desired power output. Flow through each of the stages is adjusted until the desired power output is generated, while any flow that is passing through bypass lines about each of the turbine stages is varied inversely to the variations in the flow through the turbine stages. Non-linearities occurring in the system are offset by appropriate modification of the control of each stage and by comparison of the power output of the system with the power requirements to direct continuing control until the power requirements are met.