Westinghouse Electric Corporation

Uri G Ronnen

Francesco Lardi

Leaman B Podolsky

Theodore C Giras

A system and method for operating a turbine power plant, wherein a demand signal based upon load or total turbine steam flow required for a predetermined level of operation controls the value of individual signals representative of valve position for respective steam inlet valves in the single and sequential mode of operation, is disclosed. Each individual valve position signal, which is representative of a selected portion of the total demand signal, is dynamically calculated to reflect the effect of the pressure drop across the nozzles, and to correct for the number of inlet nozzles, associated with each valve. The total demand signal is modified in accordance with actual throttle pressure over a period of time that is dependent on the amount of throttle pressure change.

System and method for controlling a turbine power plant in the single

A system and method of operating a turbine power plant utilizing a digital computer to transfer automatically between a single valve mode and sequential valve mode of operation and vice versa without disturbing the load or steam flow demand to the turbine, is disclosed. Selecting the other mode of valve operation when operating automatically in one valve mode results in the generation of physical representations corresponding to the desired flow through each of the valve means in such other mode at the operating load or flow level. The flow in the one mode and the desired flow in the other mode is used to generate a representation based on flow change for each valve means. A number of increments of valve flow change for each valve means is determined in accordance with the largest valve flow change and a predetermined limit. The size of each incremental change is determined in accordance with the respective valve flow change. The position of the appropriate valves are changed simultaneously at periodic time intervals to change the flow at each interval corresponding to its respective incremental flow change until the turbine is operated in the selected mode. A change in total steam flow demand of the turbine during such transfer suspends the transfer and changes the steam flow of the valves equally in accordance with such change. If the position of the valves does not permit an equal allocation of the total change, such change is allocated to the extent of such valves capability and the remaining change is allocated equally among the remaining valves. The transfer is resumed subsequent to effecting the total flow change.

System and method for transferring the operation of a turbine-power

A throttle valve test system for a large steam turbine functions in a turbine control system to provide throttle and governor valve test operations. The control system operates with a valve management capability to provide for pre-test governor valve mode transfer when desired, and it automatically generates feedforward valve position demand signals during and after valve tests to satisfy test and load control requirements and to provide smooth transition from valve test status to normal single or sequential governor valve operation. A digital computer is included in the control system to provide control and test functions in the generation of the valve position demand signals.

Steam turbine power plant having improved testing method and system for

A digital electrohydraulic steam turbine control system that generates a feedforward total steam flow demand signal to position the governor valves singly or sequentially in accordance with a dynamic nonlinear representation of steam flow vs. valve lift position having provision for testing the throttle valves while the turbine is operating in either the single or sequential mode and without effectively disturbing the load on the turbine and without the necessity of turbine operational feedback loops in service, is disclosed. Decremental and incremental flow changes for each of the governor valves in the test path and the non-test path, respectively, are calculated iteratives in accordance with a non-linear valve flow vs. valve lift position characterization for the total steam flow to the turbine. Subsequent to the test, the control valves are repositioned to the normal pretest sequential or operating mode by incrementally changing the flow of all the valves toward the normal operating mode position so that the net total flow is unchanged.

Growing community of inventors

Monroeville, PA, United States of America

Uri G Ronnen