Comparative Study on Flow and Heat Transfer Mechanisms Between Dual Tube Heat Exchangers and Single Tube Heat Exchangers
There have been many studies on single tube and shell heat exchangers,but there is little research on the internal flow and heat transfer mechanisms of three types of double tube and shell heat exchangers.This article establishes numerical calculation models for single tube heat exchangers,fixed tube double tube heat exchangers,U-shaped tube double tube heat exchangers,and floating head double tube heat exchangers.Through the obtained velocity and temperature fields,the differences and similarities in the flow and heat transfer characteristics of the shell and tube sides are analyzed.The research results indicate that the fundamental mechanism for enhancing heat transfer in dual tube heat exchangers is that,under the same mass flow rate on the tube side,both the flow rate and flow rate are doubled.Single tube heat exchangers and fixed tube sheet double tube heat exchangers are not suitable for situations with large temperature differences.U-shaped tube double tube heat exchangers and floating head double tube heat exchangers have one end of the tube bundle that can be freely extended and extended,making them suitable for situations with large temperature differences.The shell side comprehensive performance of the three types of double tube side heat exchangers is much higher than that of single tube side heat exchangers,while the tube side comprehensive performance is much lower than that of single tube side heat exchangers.This study can provide theoretical reference for the use and application of dual tube heat exchangers in thermal systems.
shell and tube heat exchangerdual tube heat exchangerU-tubecomputational fluid dynamics
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