Reasons for the tripping of the turbine emergency shutdown valve

Our factory experienced a malfunction once; after the compressor was modified, the overspeed protection was changed to an electronic type based on WOODWARD3 selection 2, but the mechanical flyweight was not removed. Once, the compressor stopped working for no apparent reason; after investigating the cause, it was found that there was a problem with the compression spring of the fly hammer. Haha, so the conclusion is that it also trips when there is a fault in the fly hammer system.

Recently, a shutdown occurred due to the loss of a connecting pin in the emergency shutoff device of a turbine

Tripping cause: Mechanical failure of the emergency protector led to the operation of the fly hammer； Manual shutdown ； Electrical signal malfunction.

In my workshop, the piston rod of the throttle control mechanism in the centrifugal compressor unit fell off automatically during operation, resulting in an automatic shutdown due to interlock protection… After going to the site to inspect the situation, the management remarked that such an incident could be described as something that happens once in a century

Once, the journal of the small turbine shaft of the main oil pump became corroded and thinned, causing the inner ring of the bearing to slip; as a result, the machine shut down at a speed that was not yet at the level required for emergency shutdown. The analysis indicates that the change in the trip value was caused by modifications to the rotor axis. Therefore, the change in the jump value should also be considered

I think the reason for our vehicle stopping doesn’t seem to match what you mentioned. 1. We stopped the vehicle once 3 months ago for the same reason; if it’s a problem with the flyweight compressing the spring, wouldn’t it be difficult to keep the vehicle running? 2. If the connecting pin comes loose, can’t we drive the vehicle unless we fix it? We just reset it and continued driving without addressing the issue

1. During surge conditions, excessive vibration of the unit can cause it to trip; 2. The operation of the emergency shutdown device’s flyweight can lead to tripping; 3. Human-induced shutdown actions; 4. Significant fluctuations in oil pressure can cause tripping; 5. Changes in oil pressure or oil flow due to the operation of interlock solenoids can result in tripping; 6. Aging of the springs, resulting in a loss of compressive force, can also cause tripping.

The emergency cut-off device in a steam turbine is a mechanical mechanism used for overspeed protection, as opposed to electronic overspeed protection. Therefore, under normal conditions, only overspeed can trigger the operation of the emergency shutdown device; it is assumed that the emergency shutdown device should not activate in the event of a stoppage or other interlocked stop conditions. Of course, if there is a malfunction in the mechanical device itself, then the situation described by those upstairs will occur – that is, the speed does not reach the critical level, and the emergency cut-off device will still activate. A few days ago, in discussions with Siemens technicians, it was learned that Siemens’ drive turbines currently come equipped mainly with electronic overspeed protection, and no longer have such mechanical overspeed protection devices as emergency shut-off valves.