Butterfly valves are widely used in industrial field

and under certain working conditions

strong unstable flow will occur in the butterfly valve and cause vibration in pipeline system. By taking the connecting pipe of the medium and low pressure cylinder of a 600 MW heating unit as the research object

the mechanism of unstable flow in the butterfly valve and the vibration of the connecting pipe was revealed through the combination of field measurement and steady numerical simulation. Then

based on the flow pattern optimization

a new type of butterfly valve with valve plate and diversion structure was designed

and the unsteady numerical simulation of the maximum vibration condition of the original butterfly valve and the optimized butterfly valve was carried out. The results show that

after adding the flow-guiding structure to the valve plate

most of the main steam flow moves along the middle of the steam inlet pipe of the low-pressure cylinder. This can effectively weaken the exciting force generated by unstable flow and suppress the vibration of the connecting pipe. The new butterfly valve proposed can be applied to suppress the vibration of the pipeline system with small opening of the butterfly valve.