Study of Vibration and Sound Transmission Characteristics in Condenser Pipe System

Effect of surrounding fluid or steam flow fluctuation on internal flow fluctuation in heat transfer pipe is analyzed based on fluid and structure interaction simulation by using commercial code Ansys workbench. Simulation results show that the effect of surrounding steam could be ignored, as the difference between pipe wall vibration level actuated by surrounding fluid flow and that actuated by surrounding steam flow is very notable. The results also show the internal flow pressure fluctuation spectrum is well in accordance with that of surrounding flow. Then the effect of surrounding fluid fluctuation on internal flow noise transmission in heat transfer pipe is taken into considered and the insertion loss of circulation coolant water flow noise between condenser inlet and outlet is calculated by a matrix transfer method developed in this paper. An experiment on 3t/h class condenser system is conducted, the experimental results of insertion loss of vibration level and coolant flow noise between condenser inlet and outlet is a little larger than the calculated results, as the effect of condense shell structure is not considered in the model. It can be concluded that, 1, internal coolant flow and the pipe structure are closely coupled, and hereby flow fluctuation is an important contribution to pipe vibration level in condenser pipe system. 2, surrounding flow actuating vibration of heat transfer pipe is mostly induced by condensate fluctuation at the bottom area while the top area steam flow fluctuation induced pipe vibration is neglectable. 3, insertion loss of vibration level and coolant flow noise between condenser inlet and outlet changes little as operation condition changes.