| 摘要 |
A steam turbine installation includes a safety system located in the steam flow path having a stop valve located in the steam flow path upstream of the turbine and a vacuum break valve located in the stream flow path downstream of the turbine, and a combined regulating and safety device connected to the turbine produces signals for controlling these valves. In addition, a signal from a steam flow monitor located downstream of the stop valve is supplied to a logic system, this signal having a value which normally corresponds to the setting of the stop valve. In the event of a disparity the logic system functions to trip the regulating and safety device which results in a closure of the stop valve and a partial opening of the vacuum break valve. Upon detection of a further mass flow by the steam flow monitor after the partial vacuum condition has been reached the logic system functions to move the vacuum break valve to full open position and activate a water injection valve that sprays cooling water on the last rows of the low pressure blading of the turbine.
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