Problems with twin-screw oil pumps
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The unit is equipped with two screw oil pumps, one in operation and the other as a standby unit. The inlet and outlet valves of the standby pump are kept fully open; however, it often takes a few seconds after switching to standby mode for pressure to be reached, and by that time the unit has already shut down due to the interlock mechanism. When the spare pump was disassembled, there was very little oil inside it. What could be the reason for this? If any fellow travelers know, please help. Thank you.
We have also encountered this situation: the unit experienced voltage fluctuations, which caused the pump to stop operating. The backup pump started a few seconds later as part of the interlock mechanism, and pressure was finally achieved; however, due to insufficient oil pressure, the turbine’s quick-shut valve closed, forcing the unit to shut down. Finally, we increased the interlock value so that the backup pump starts when the oil pressure is not particularly low. Prevent delayed startup of the backup pump, which could lead to cascading shutdowns.
The interlock shutdown value can also be delayed by a few seconds to give the backup pump enough time to start. Or install a check valve on the main oil pressure line to prevent the oil pressure from dropping too quickly
I feel the same; it got better after making adjustments
Start one pump first; once it is operating stably, switch to the backup pump. The standby pump serves as the operating pump; start the one that is designated as the standby pump first. This prevents a shutdown due to a faulty backup pump in an emergency situation.
This might be related to the operation. By design, both pump outlets are equipped with check valves, so backflow generally does not occur. Two days before the unit is started, the pumps need to be operated, and it is necessary to ensure that each pump is filled with oil to avoid problems that may occur during sudden startup. Secondly, turbine oil systems typically come equipped with accumulators, which help to prevent significant fluctuations in oil pressure over short periods of time.