Design and application of a new distributed pulsating flow generator in elastic tube bundle heat exchanger

Abstract

In order to realize reasonable and effective excitation of the vibrations in heat exchanger, a new distributed pulsating flow generator (DPFG) is proposed. The pulsating flow frequencies and intensities of different branch pipes of the DPFG are studied. Based on the vibration test bed, the vibration characteristics of the elastic tube bundles (ETBs) are tested. In addition, the heat transfer performances (HTPs) of the ETBs are numerical studied under different flow-induced conditions. The results indicate that the pulsating flows with substantially the same frequency and intensity can be generated in all branch pipes of the DPFG based on the appropriate sizes of vertical pipe and horizontal pipe. For the ETBs suffer the pulsating fluid and shell-side fluid, the ETBs have two vibration frequencies, i.e. the constant frequency and variable frequency. The constant frequency is caused by the shell-side fluid, and the variable frequency is caused by the pulsating fluid. In addition, the DPFG not only greatly improves the vibration intensities and uniformity of the ETBs, but also greatly improves the HTPs.