摘要 |
The present invention is a method of minimizing steam boiler pressure changes or turbine power changes during turbine control valve operational safety test stroking. The method of the present invention uses control valve positions as feedback into a compensation algorithm to minimize flow disturbance caused by the closing and reopening of a turbine control valve during periodic operational testing. By maintaining the total mass flow through several parallel turbine inlet control valves constant, the steam generator pressure is maintained constant, and the inlet pressure regulator is unaffected during inlet control valve testing. Maintaining the total mass flow through several parallel turbine inlet control valves constant also minimizes turbine power changes during inlet control valve testing. In addition, the monitoring of additional process parameters is not needed. The position (valve stem lift) of the individual parallel valves is used for closed loop control of inlet valve position, and is sufficient for the purpose of maintaining constant flow.
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