Question

INCORRECT In the case of a partial load rejection, the governor would throttle-in the main steam control valves. if there was no reheat intercept valve, there could be turbine "overspeed" because the steam pressure would suddenly 1se the steam flow would suddenly increase steam would continue to pass through the high pressure turbine CS tas canned with CamScanner uld 5s through ttie mtermediate and low pressure turbines INCORRECT In the pilot valve hydraulc control system, the pilot valve is returned to its neutral position by the governor the power piston, by means of a reset lever the double-relay valve cs Scanned with the compre Sio s canner INCOP ORRECT The turbine stearm admission valves, or control valves, are opened one at a tume, the others remaining closed several at a time, under individual control, as required n sequence, according to the position of the cross arm Cs Scanned with us GEm Sca Pver sImuttane the cross am On modern machines, it is more common to use a mechanical governor an electronc type of speed sensor and an electro hydraulic governor a bydrauc governor CS Seanned with sale tym'S cat merohdr ar eeuselc dtaulic governor or a hydraulic governor INCORRECT hen the steam chest is fully charged the stop valve is opened wide the stop valve drains are throttled in the stop valve drans are partally throttled in he ston ya lvegpenantmerchd peirebvalve drains are thiottled in CS CamScanner the sop valve is opened wide and the stop valve drains are partially throttled in INCORRECT The procedure for charging the generator with hydrogen takes several to complete seconds minutes bours Cs Scanned with CamScanner INCO RRECT One important reason for loading the turbine quickty to its minimum required toad is to minimize vibration to avoid overheating of the low pressure turbine blades to avoid overtheatin8ef theigh psure tuibime blades CamScanner oavDl wasting heat in the bypass atrangement INCORRECT There is a temperature gradient between the inner and outer diameter of the steam chest because the hot steam is next to the inner wall the outside surtace loses heat to atmosphere, even though it is well insulated the steam chest wall is made of a dense material all-ef-theabo.canned with CS CamScannere d the outside suiface loses heat to atmosphere, even though it is well insulated INCORRECT During turbine start-up, harmful condensation of steam will occur in the su heater tubes the pipework the turbine all of the above Ias Scanned with aTramScanner he pnewod INCORRECT When the turbine is on-load, a possible source of water ingress into the turbine is condensation in the reheater water drawn into the reheater from the blowdown tank feedwater heater leakage through the extraction steam Iines cs Scanned with CamS.canne rawn te above into the reheater from the blowdown tank ndensatiorthbtenee INCORRECT Fo: turbine operation, the indications we are most interested in are pressure and temperature, vacuum and feedwater conditions steam lube oil temperatures and bearing vibration the turbine's mechanical condition as indicated by the supervisory instruments all-of-the above Scanned with CS amScanner ressure and temperature. vacuum and feedwater conditions and lube oil temperatures and bearing vibration INCORRECT Tripping the main steam stop valve also actuates the positive closure of nan-return valves on the extraction fines. This is necessary to prevent the main steam from being drawn off by the extraction lines ssof vacuum at the low pressure end of the turbine entranestepan from entering the tusyne and aggravating the overspeed condition Cs Scanned with CamScanner water fro enteing the turbine from the blowdown tank INCORRECT In seme plants, the turbine generator may remain on-load for many months at a time, In this case, some form of simulated test of protection devices may I overspeed trip mechanism may be tested by carried out, For example. the taking the turbine and generator off line for a few seconds to perform the test computer simulation operating part of it but blocking the actual tripping of the turbine Cs Scanned with nthe re dn ain immediately after the stop valve closes INCORRECT In newer plant installations and in many converted plants, digital control systems are employed and the operator works at a console with three or faur CRTs, providing. indications alarms the means for remote opetation all of the above Scanned with ndiantions.ana rarsoanneFoperation INCORRECT During a short shutdiown, say overnight, or even for a few days, it is normal to leave the generator rotating on the turning gear keep the generator charged with hydrogen open all steam valves all of the above cs Scanned with arthe genera@rlag Ghhe aning gear and keep the generator charged with hydtogen INCORRECT When the turbine is on load, the heating of the nozzle block is more even than during start-up because more of the valves are open the turbine is turning faster the block has more time to reach an equilibrium temperature distribution all-of-the above Scanned with amSannee block has more time to reach an equilibrium temperature distribution neauoine is t INCORRECT During a short shutdown, say overnight, or even for a few days, it is normal to leave the generator rotating on the turning gear keep the generator charged with hydrogen open all steam valves allof the above eS Scanned with CamScanner ator rotating on the turning gear and keep the generator charged with hydrogen eave INCORRECT f the turning gear farls and the rotor must be rotated by hand, a typical procedure would be to rotate it 180 degrees every minute 5 minutes half hour CS Scanned with CamScanner hours INCORRECT If there were no reheat stop valves fitted on the reheat turbine, the consequence of an emergency trip would be a boiler explosion a boiler implosion a turbine "overspeed" exalosion or a turbine overspeed Scanned with CamSc ller implosion or a turbineoverened" INCORRECT The reheat intercept valve is used when there is a sudden increase of steam pressure there is a new electrical load that is suddenly added to the system there is a partial load rejection that the main control valves cannot accommodate ofNhe above Scanned with CS CamScannerenly added to the system or there is a partial load rejection that the main control valves cannot accommodate INCORRECT Eventually, after start-up is complete, the casing expands further and further, and the differential axial expansion decreases and settles down to approximately 1 mil 5 mil 10 mil Scanned with CS CamScanner mi INCORRECT During turbine start-up, harmful condensation of steam will occur in the superheater tubes the pipework the turbine allof the aboanned with CS Cam Scanner the pipework and the turbine

Answer 1

Hello,
       Please find the answers to the first 4 incorrect questions attached below. If the answer has helped you please give a thumbs up rating. Thank you and have a nice day!

1. Turbine overspeed is caused because steam pressure would suddenly rise.

2. The pilot valve is returned to its neutral position by the compression valve (system)

3. The turbine steam admission valves are opened in sequence, according to the position of the cross arm

4. The stop valve is opened wide and the stop valve drains are partially throttled in.

NOTE: There are a lot of questions posted here. Please post these questions one by one, to get all of them answered!. It may not be possible for a single eexpert to answer all of these at one go!

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