A system for holding a substantially constant pressure level in the medium pressure steam system of an integrated plant, despite any sudden shutdown of a high pressure steam turbine. A combination quick-opening and a control valve is provided with a hold-down operator and positioning actuator with a spring drive, the hold-down operator being connected through a changeover valve with a working pressure system. The positioning actuator is connected to an additional change-over valve and to the out...

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...

Steam flow to a turbine is reduced by partially closing intercept control valves to reduce turbine speed to a reference speed after sudden increases above this speed caused by sudden decreases in turbine load. Circuitry for developing a command signal for closing the valves in response to a difference between the reference speed and the actual speed of the turbine is provided. The command signal magnitude is varied to cause rapid closing motion of the valves during that portion of valve movement...

A digital transfer system for transferring the operation of a steam turbine between a single and sequential mode of operation is disclosed. A total flow demand signal is applied to all of the valves in parallel for the single mode; and applied to all of the valves through individual function generators for the sequential mode. A digital up/down counter is connected to a rate multiplier for generating pulses at a frequency corresponding to the status of the counter. An electronic switch is connec...

A protection system is provided for a turbine plant to avoid double shock or similar rotor blade operation. A digital computer controller detects excessive blade loading conditions on the basis of governor valve positions and effects bumpless mode transfer from sequential valve operation to single valve operation to avoid excessive blade loading.

A speed control device is constituted of an acceleration control device used for starting a turbine, a constant speed control device used for the constant speed operation of the turbine and a selection circuit for selecting that one of the outputs of the control devices which makes smaller the opening of an adjustable valve provided at the entrance of the turbine. The output of the selection circuit determines the opening of the valve. The speed control device is so designed that the speed regul...

Method for improving the heat rate of a steam turbine operated in a partial-arc mode includes sequential closing of control valves to establish a first arc of admission at which pressure drop on a first control stage reaches a predetermined level. Steam pressure to the turbine may then be reduced in combination with valve closing to maintain first stage pressure at or below the predetermined level. In a further method, low power operation is achieved by maintaining a constant arc of admission wh...

The present invention involves a system for controlling the electric charge within the exhaust hood and condenser of a steam turbine by using shaft current as an indirect measurement of exhaust charge, and then adjusting the pH accordingly. The present invention uses the turbine-generator shaft 12 instead of a probe, and therefore measures the potential of the current in the shaft to the ground. This measurement 32 is then fed into a control unit 40 which adjusts the chemical feed 42 to the feed...

An apparatus and method for converting a differential in thermal energy between a first thermal source having a thermal conducting fluid and a second thermal source having a thermal conducting fluid is provided. The apparatus emplys a first vessel and a second vessel. Each of the vessels contain a gas under pressure The vessels contain heat exchanging coils that are connected to the thermal sources by fluid lines. A plurality of cooperating valves regulate the flow of the thermal conducting flui...

A device for utilizing waste heat from a heat engine comprises a Rankine cycle including a pump, a heating device, an expansion device, and a condenser device, and a controller for controlling an operation of the Rankine cycle. The controller calculates an optimum heat collection amount (Qho) as a heat value to be collected from waste heat of the engine, wherein the heat collection amount (Qho) is calculated as an optimum amount in relation to a potential maximum heat radiation amount (Qco) to b...