Abstract
We conducted two sets of experiments, one is under steady-state conditions and the other under pulsating conditions. We focused on measuring the heat transfer characteristics of plate heat exchangers under different pulsation conditions. In the experiment, we control the mass flow of the hot fluid to circulate at a rate of 0.722 kg/s. The mass flow rate of the cold fluid is 0.05-0.18 kg/s, and the pulsation frequency is 0.45-2.23 Hz. We measured different mass flows at different pulsation frequency. The data analysis shows that when the pulsation frequency is 1.78 Hz, the heat transfer coefficient reaches a maximum of 4415.73 w/(m2·k), and the corresponding cold fluid mass flow rate is 0.155 kg/s, and compared with the heat transfer characteristics of the plate heat exchanger under steady flow, it is found that the average increase in the heat transfer coefficient during the transition to the pulsating mode was 20%.
Highlights
Heat transfer under pulsating flow has applications in various fields and industrial engineering
When the frequency is less than 1.78 Hz, the heat transfer coefficient increases with the frequency, and when the frequency is more than 1.78 Hz, the heat transfer coefficient decreases with frequency
When the pulsation frequency is 2.23 Hz, the heat transfer coefficient increases first and decreases with the mass flow, when the mass flow is less than 0.155 kg/s, higher pulsating frequency corresponding to higher heat transfer coefficient, when the mass flow is more than 0.155 kg/s, higher pulsating frequency corresponding to less heat transfer coefficient
Summary
Heat transfer under pulsating flow has applications in various fields and industrial engineering. The factors affecting the heat transfer effect of pulsating fluid are Reynolds number, pulsation frequency, pulsation amplitude, pulsation speed, the geometry of flow channel, the installation position of pulsation generator, pulsation waveform, fluid medium, inherent physical parameters of the system, etc. Low amplitude, high Reynolds number, a pulsation velocity gradient is applied to enhance heat transfer, and pulsating flow is used as an active heat transfer enhancement technology. E. Zohir [4] studying the downstream and countercurrent flow heat transfer characteristics of concentric tube hot and cold fluid under pulsating conditions under high Reynolds number, the Nusselt number increases by 20% under downstream conditions, and the Nusselt number increases 90% under countercurrent conditions, the correlation for the average Nusselt number is confirmed to be 12% of the maximum error at different pulsation frequencies and Reynolds numbers. The effect of pulse perturbation on the convective heat transfer of the coaxial cylindrical tube heat exchanger, the experiment found that the pulse can significantly increase the heat transfer coefficient by 300%
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
