Situation Flashcards
Problem: While inspecting F-6101, you find that the burner flames are rising to the convection section tubes and laying down black soot. What is the probable cause? How would you correct it?
Probable cause:
A probable cause to this issue could be that there is a partially plugged burner. This could cause the unplugged nozzles on the partially plugged burner to receive a higher pressure of fuel gas. The result of this problem could cause the burner flame to rise into the convection section tubes due to the unplugged nozzles on this burner receiving excessively high fuel gas pressure.
Another possibility that could lead to this problem, could be that F-6101 is receiving an excessive amount of fuel gas and not enough oxygen to complete the combustion. This could be caused by a change in the specific gravity of the fuel gas that has lowered the BTU value. This scenario would cause the temperature to drop, which would cause the temperature indicator to read a low outlet temperature on the transfer line, TC-105 would then signal FC-168 to increase its output which would increase the fuel gas to keep the temperature at the desired setpoint. The increase of the fuel gas in the furnace could be the cause of the burner flames rising to the convection section. This situation would lead to unburned fuel gas in the furnace and with the insufficient oxygen this could bring the furnace into a bogging condition.
Corrective actions:
The corrective action for a partially plugged burner would be to take the burner out of service to be cleaned. If there was an unlit burner available, it would need to be relit.
Once the problem of the burner flames going into the convection section has been recognized the outside operator would inform the console and head operator. The outside operator would keep good communication as the console operator begins to make moves on the furnace. The outside operator would verify what the positions of HC-176 and HC-174 are in the field. The outside operator should then check and blowdown if needed the fuel gas coalescer K-6117. After that the outside operator should check the forced draft fan K-6104 and the induced draft fan K-6105 to see what the local speed indication is reading and if it matches what the console is seeing.
Problem: During your routine rounds you notice hydrocarbon coming out around the carbon seals on TP-6109A. A check at plot limit shows no hydrocarbon in the steam at that location. List the probable cause/causes and how to correct this situation.
Probable Causes:
One possibility is the boiler plant, which supplies Crude II with 150 # steam, should be notified because there is a possibility of hydrocarbon coming from there. Even if it is not showing hydrocarbon present at plot limit, it is possible that it is coming in spurts from the boiler plant. The outside operator should keep an eye out on other equipment being driven by 150# steam.
A possibility that could lead to this issue could be that one of the 60# steam generators, E-6112 or E-6114 has developed a tube leak. This would lead to either 3rd side cut HSGO, or 7th side cut Heavy HDN, getting into to the low-pressure boiler feed water in the steam generator. Hydrocarbon is lighter than water, so it would float on top. This would then allow the hydrocarbon to become entrained in the 60# steam header through the steam outlet of the steam generator. The 60# steam header lets down to the 40# pound steam header which could allow hydrocarbon into the 40# steam header. On TP-6109A the 150# inlet steam is blocked when not running while the 40# exhaust is open to allow the turbine case to stay hot, this could allow the hydrocarbon to get into the turbine case from the 40# pound steam header.
Another possibility could be that a check valve has failed on a utility connection that is connected to a 150# steam line. If this were connected to a hydrocarbon system that was at a higher pressure, the hydrocarbon could back into the 150# steam header and end up in the TP-6109A case through the inlet steam.
Corrective actions:
Once the hydrocarbon coming out of the carbon seals of the turbine has been discovered the outside operator should inform the head operator of the situation. The next step would be to identify which steam generator has the leak and is allowing hydrocarbon into the steam. The outside operator would check the sight glasses for Hydrocarbon and take samples to identify the steam generator with the leaking tube. Once the defective steam generator has been determined it should be bypassed, blocked in, LOTO’d, and a work request written for maintenance to come and replace or repair the tubes.
The corrective action for the failed check valve on the utility connection would be to first block in the steam and the hydrocarbon source. Next you would de-pressure the utility connection and remove it. Check the bleeder of the upstream check valve, if there is hydrocarbon present, then it should be tagged as a bad utility connection.
Problem: During your routine round you discover that P-6120 I.B. seal is leaking badly.
P-6120A is on stand-by (slow rolling). List all moves required to handle this emergency.
Solution:
Once the outside operator has found the leaking seal, they should make sure they are in a safe position, make sure any non-essential personnel is evacuated, immediately notify the console and head operator of the situation, assess the situation and inform them of the severity of the leak. It may be best to trip the EBV. The residuum could auto ignite so tripping the EBV would be the best option to prevent a fire. There is a panel south of C-6107 that can be operated to close the EBV, but in this situation it may be better for the outside operator to ask the console operator to close the EBV from inside due to the distance from the pump to the EBV panel. At this time the operator should go north of K-6117 fuel gas coalescer and turn on the deluge spray system to the pump to try to prevent the leak from catching fire. Once the EBV has successfully been shut, the pump should cut off, this should stop the flow of residuum to the pump case. The operator should listen for the check valve and make sure that the pump does not start spinning backwards. If the check valve holds and the seal has stopped leaking and it is safe to approach. The operator can work on getting TP-6120A online. However, if the check valve does not hold and the seal is still leaking the next step would be to get the discharge valve blocked to isolate the leak. If this were the case the operator should have backup with hoses spraying around the leak to attempt to prevent the leak from lighting off, while they are blocking in the discharge. Good communication should be maintained throughout this entire situation.
Once the leak has been isolated and the situation is mitigated, the operator should then verify everything is lined up correctly, then bring the TP-6120A online. The pump is already on a slow roll, so the operator should just have to increase the steam flow and bring the turbine up to speed. Once TP-6120A is online the operator should then begin to block in the discharge and suction of MP-6120 to make sure it is isolated to prevent anymore residuum from possibly getting to the damaged seal. Next the pump will need to be locked out following RI-107 for maintenance to repair the seal. The operator should refer to 061-JA-4520, removing hot oil pump from service, and use it in the field to take the pump out of service and prepare it for maintenance. This pump has residuum, so it needs to be case flushed with the 5th S/C to purge and prevent the residuum from hardening. All safety measures should still be in place while flushing because resid and/or 5th side cut could leak from the blown seal. Once the pump case has been thoroughly flushed with 5th S/C back to C-6102, a water flush to the OWS can be utilized as an added measure. At this time, the LOTO of the pump can be completed and turned over to maintenance.
PROBLEM: Over a period of a few days, you notice that the vacuum on the surface condenser has dropped slowly, and the hot well temperature has increased. What is the probable cause, and how would you go about correcting this problem?
Common causes for the loss of vacuum:
* TP-6101/02A turbine seals leaking
* PRD leaking
* Bad ejector
* Condensate pump leak
* Possible air leakage- such as flanges, bull plugs etc.
Corrective Actions:
Notify Head operator and Console operator of your findings.
Visually check the water seal on the PRD’s to verify that water flow has not been lost.
Make sure that cooling water supply and return are lined up properly and nothing is leaking.
Make sure that MP-6155 or either TP-6155A is running and has a small amount of water coming out of seals to ensure that no air is entering the system. Suction screens could also be plugged.
Check the level in the hot well, if the level is too high it could be possible that the tubes are submerged and not making the necessary heat transfer take place.
Check the sealing steam on TP-6101A and TP-6102A.
Make sure that TP-6101A and TP-6102A condensate pots are drained and bleeders are closed and bull plugged. Condensate can fill the turbine case and cause damage to the turbine if the condensate pots are full.
The outside operator could swap ejectors on the inter condenser and the after condenser to verify that they are not causing the problem.
The outside operator could backflush the surface condenser to try to resolve the situation. Gen-JA-4605 should be used to backflush condenser.
