Westinghouse Electric Corporation

Thomas H McCloskey

Leaman B Podolsky

Morton H Binstock

Bernard L LaCoste

A bypass system for a steam turbine wherein the energy level of the steam bypassed around the intermediate pressure and low pressure turbines is modified by introduction of cooling water. The amount of water introduced is adaptively varied as a function of the enthalpy of the bypassed steam as measured by a sensor in the steam path.

Turbine low pressure bypass spray valve control system and method

A DEH (digital electrohydraulic) control system for a steam turbine generator having a steam bypass system. The turbine system includes a high pressure turbine having throttle and governor steam admission valves as well as an intermediate pressure turbine having stop and interceptor steam admission valves. The turbine is brought on line by initially controlling steam admission into the intermediate pressure turbine by modulating the interceptor valve in response to a speed error signal generated as a result of the difference between actual and a predetermined reference speed. During this initial control the throttle valve remains in a closed position. When the turbine speed has attained a preset value such as half of synchronous speed, the interceptor valve is held at the same position it was in when the preset speed was attained and the throttle valve is controllably open in response to the same speed error signal. After a preset transfer speed has been attained, control of steam admission to the high pressure turbine is transferred to the governor valve and after synchronous speed has been reached the DEH system switches to a load control mode wherein the signal which controls the positioning of the governor valve is also utilized to control the interceptor valve position. The interceptor valve thereafter will reach a wide open position at a predetermined load. During the speed control mode of operation the control signal which controls the positioning of the interceptor valve is modified by certain pressure conditions at the input of the interceptor valve after the preset speed is attained.

Control system and method for a steam turbine having a steam bypass

A bypass system for a steam turbine wherein the temperature of the steam bypassed around the high pressure turbine is accurately controlled by measuring the inlet and outlet temperatures of the boiler reheater and generating an adaptive set point. The set point value is used to govern operation of a spray valve which admits cooling water to the bypass steam path.

Turbine high pressure bypass temperature control system and method

A steam turbine system which includes a steam generator and a steam bypass path for bypassing steam around the turbine. The outlet throttle pressure of the steam generator is controlled by controlling admission of steam into the bypass path by means of a bypass valve. A desired throttle pressure set point is generated which is independent of steam flow and this set point is compared with the actual throttle pressure for governing the bypass valve during turbine start-up. When the turbine is fully operational the bypass valve control is effected by a comparison of the actual throttle pressure with the desired throttle pressure set point plus some bias.

Turbine high pressure bypass pressure control system

A shaft seal device for a butterfly valve shaft wherein a friction face seal device having a flexible double bellows arrangement thereon is disposed within a seal chamber between a contaminated source of pressurized steam and a low pressure gland condenser. A buffer layer of uncontaminated steam having a pressure higher than the pressure of the contaminated steam is introduced into the seal chamber through conduit means. The buffer layer of uncontaminated steam having a pressure higher than the pressure of the contaminated steam is disposed between the contaminated steam source and the gland condenser to insure zero leakage of contaminated steam past the double bellows seal device into the gland condenser.

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Palo Alto, CA, United States of America

Thomas H McCloskey