Study On The Flow And Heat Transfer Mechanism In The Corrugated Channel Of Chevron Plate Heat Exchanger

The chevron plate heat exchanger is a commonly used heat exchange device,which has a compact structure and excellent heat transfer properties and has been rapidly developed in recent years.However,there are also disadvantages such as large flow resistance and poor pressure capacity.Therefore,it is of great practical significance to deeply study the internal mechanisms and laws of fluid flow and heat transfer in the corrugated channel of chevron heat exchangers.In this paper,two-dimensional physical models of the corrugated channel of the chevron plate heat exchanger are established,and determined the mathematical model and the grid division method.The error range between the simulation results and the experimental data in steady state and unsteady state is 3.45%~8.92%,and the verification model is reliable.In steady-state simulations,studies have been carried out for corrugation heights H=3,4.5 and 6 mm,corrugation pitch ?=8,11 and 16 mm,and Re=2000-9000.Under the influence of the changes in Reynolds number and structural parameters,the average number of local and surface features along the corrugated channel walls and the variation of local velocity,temperature,and turbulent kinetic energy of the fluid in the internal transverse profile are analyzed.The results show that by increasing the Reynolds number and the corrugation height,decreasing the corrugation spacing can increase (?) of the concave and convex wall surface and increase the overall Nuxcurve;while decreasing the Reynolds number and the corrugation pitch,increasing the corrugation height can increase the(?) of the corrugated wall surface and increase the overall fx curve.Eddy currents along the concave wall surface mainly occur in the front and middle of the flow channel,and there is almost no vortex flow at the tail.In the non-stationary simulations,studies were performed for corrugation heights H=3,4.5,and 6 mm,corrugation pitch ?=8,11 and 16 mm,Re=600,t=0.25 T,0.5T,0.75 T,and T.The distribution regularity of average and local surface features along the concave-convex wall surface of the corrugated channel and the evolution of the vortex,flow,and heat transfer parameters between the corrugated channels at different times in the unsteady state under the influence of flow time and structural parameter changes are analyzed.The results show that with the increase of time,the small structure-scale vortexes of strenuous movement gradually break up and fuse into a stable low-velocity large-area reflow,while the temperature boundary layer gradually becomes thicker.Increasing the corrugation height and reducing the corrugation pitch can increase the range of vortex generation and the severity of the flow.At the same time,it also aggravates the local high-temperature phenomenon and makes the pressure distributionin the flow channel uneven.