Abstract: Methods and apparatus are described for cleaning and recycling flexible floating cleaning plugs introduced into and propelled by water pressure through the cooling water tubes of a power plant heat exchanger located near a flowing body of water. A cooling water outlet conduit delivers used cooling water from the exit end of the heat exchanger cooling water tubes, together with a plurality of flexible floating cleaning plugs propelled therethrough, discharging them into the flowing body of water upstream from a containment barrier. The barrier has a convergent weir region at its downstream end, and a conveyor carries floating cleaning plugs from the convergent weir through a washing spray positioned to sluice away the accumulated scale, sediment, dirt and sludge gathered by the plugs from the cooling water tubes. A cooling water pump has its intake positioned far downstream in said flowing body of water or in a different body of water.

Abstract: An overspeed protection controller (OPC) which is incorporated as part of a turbine speed/load control system for the purposes of controlling the monitored speed of a steam turbine at a first predetermined speed valve subsequent to an OPC activation is disclosed. The governor and interceptor valves of the steam turbine are positioned controlled by a set of electrohydraulically operated valve position servo systems. The OPC provides for rapid hydraulic closure of each valve when activated by either a detection of an interruption of generated electrical power flow to a power system load when the generated electrical power is greater than a predetermined value or the detection of the monitored turbine speed being greater than a second predetermined speed value. The rapid closure of the valves results in an interruption of steam flow to the high and lower pressure turbine sections of the turbine system which causes steam energy to be trapped in the reheater which is disposed between the turbine sections.

Abstract: A system and method for complete on line testing of the emergency trip system of a turbine power plant is disclosed. The mechanical trip valve and a portion of a line to drain, of the emergency trip system, are isolated from the remaining portions thereof. The testing of the valve is permitted without an opening to drain of the line, which would cause a turbine trip. A three-way solenoid valve obstructs the line to isolate an upstream portion from a downstream portion while permitting introduction of fluid into the downstream portion at a pressure distinct from that in the isolated upstream portion. Pressure sensitive switches, which operate suitable indications are provided in fluid communication with both portions of the line to drain to sense the differential pressure therebetween upon operation of the solenoid valve and, subsequently, a rapid diminishing of pressure in the downstream portion indicative of a successful test of the mechanical trip valve.

Abstract: An electrohydraulic emergency trip system which automatically shuts off the steam supply to a turbine power plant upon the detection of specific operational contingencies is disclosed. The hydraulic portion of the system includes two pair of combined electrical and hydraulically operated pilot trip valves that are so arranged that the opening of any one valve of each pair decreases the hydraulic trip pressure to close rapidly the steam inlet valves to the turbine; that an open or closed failure of a single trip valve does not prevent a valid trip or cause an unwarranted trip; and finally that an open failure of one pair of the valves does not result in an unwarranted trip. Each pair of valves is electrically operated from an independent voltage source such that the electrical failure of one source does not cause or prevent an unwarranted turbine trip.