Vibration in the turbine inlet pipeline
Thread Content
What is the cause of excessive vibration in the medium-pressure steam pipeline at the inlet of the back-pressure single-stage turbine used to drive the circulating water pump? Please provide an analysis!
Generally, this is pipe vibration caused by resonance. The general solution is to add supports for fixation to the vibrating pipeline.
According to the equipment operators, the speed of the turbine has decreased. Medium-pressure steam at the inlet is being directed into the low-pressure steam pipeline at the outlet, which results in a small pressure difference between the inlet and outlet of the turbine. This, in turn, causes vibration in the medium-pressure steam pipeline at the inlet. I don’t understand why this happens
Resonance is a coincidence: during the flow of steam, there is a natural vibration frequency, and when this frequency coincides with the natural vibration frequency of the pipe or the equipment itself, vibration occurs. The purpose of adding fixed brackets is to disrupt this overlap. Additionally, changing the flow rate and pressure of the steam can also disrupt this overlap.
An increase in the back pressure of the turbine can potentially lead to an increase in vibration levels; it is advisable to check this； Furthermore, if the flow rate in the medium-pressure steam pipeline is not selected appropriately, or if the positions of the fixing points are not set properly and the fixings are not secure, this can all lead to vibration
Loose pipe supports, high thermal stress, water hammer