Thank you to the turbine expert for their guidance
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The turbines in our factory are from Nanjing Steam Engine Company; now, once the rotational speed reaches over 2960, the high-pressure valve automatically closes and swings. The rated speed is 3,000 revolutions per minute. The oil quality issue has been ruled out, and there are no fluctuations in oil pressure. The instrument’s electro-hydraulic converter has been replaced, and no problems can be detected at present. Please advise, experts
Can the secondary oil pressure and electrical signals be matched? :dizzy: Move the stool, wait for the expert
There’s a problem with the eccentric flyweight; increase the spring force.
First: 1. Initially investigate the cause of the shutdown – determine whether it was caused by an electrical protection mechanism activating (by checking the DCS and other related electrical protection systems as well as historical records), or by mechanical reasons； 2. If electrical factors are ruled out, check whether the emergency cut-off switch activated at the time of shutdown (if it did, it’s possible that the fly hammer acted prematurely); if not, further inspection is required, such as checking the spool valves and springs inside the hydraulic actuator. The above is only an inspection and analysis based on the information you provided; the actual situation on site will need to be taken into account as well.
What you have shut down is the high-pressure valve, not the main steam valve; in the event of an emergency shutdown or a flywheel action, it is the main steam valve that needs to be shut off. The operation of the high-pressure valve is controlled by the electro-hydraulic converter (DDV or servo valve). The first thing to check is whether there is any change in the stroke of the valve element in the electro-hydraulic converter, that is, whether the converter’s operation triggers the movement of the hydraulic actuator. It is also necessary to check whether the servo controller in the DEH system is sending signals to the DDV valve, to determine if there are instructions coming from the DEH system. Another consideration is the oil pressure issue; generally, the DEH system includes a setting for switching between the high-pressure oil pump and the main oil pump. If the high-pressure oil pump shuts off automatically at 2960 revolutions per minute, and the main oil pump has not yet started working properly, this can cause significant fluctuations in oil pressure, which may result in the high-pressure valve closing. In short, it is necessary to determine whether the shutdown was caused by some instruction or by certain conditions not being met