Experimental And Numerical Study Of Flow And Heat Transfer In V-corrugated Plate Heat Exchanger

Plate heat exchanger are widely used in energy power,chemical production,refrigeration and mechanical processing.It has many advantages such as compactness,flexibility and high heat exchange efficiency,which has attracted many scholars from home and abroad to study it.From the published literature,we found that the study of plate heat exchanger mainly focuses on its ripple inclination,wave height and wave pitch.By changing these parameters and analyzing the heat transfer characteristics data to obtain the best geometry.However,there are few articles to study or pay attention to the influence of the number of V-corrugated of the plate on the heat transfer characteristics,and theoretical research on the heat transfer mechanism of corrugated plate heat exchanger with different V-corrugated numbers is rare.A multi-V-corrugated plate heat exchanger having a V-corrugated structure on the plate surface is used herein.The experimental study and numerical simulation analysis are combined to study the flow and heat transfer characteristics between the plates,and the mechanism of flow heat transfer is discussed in depth.Firstly,in order to study the heat transfer and resistance characteristics of multi-V-corrugated plate heat exchanger,this paper builds a test bench for heat exchange system.The experiment is divided into two parts: one is water as working medium;the other is the lubrication-water test section in which the lubrication is used as the research working medium for the heat exchange with water.In the experimental operation,a series of experimental parameters were obtained by changing the volume flow rate and temperature parameters of the inlet of the multi-V-corrugated plate heat exchanger,and the data were analyzed and the experimental error was eliminated.The empirical correlation of heat transfer flow is derived,and the overall performance of the plate heat exchanger is analyzed by the area heat transfer factor and compared with the shell-and-tube heat exchanger.The experimental results show that the heat transfer,heat transfer coefficient and pressure drop of the heat exchanger increase with the increase of the volume flow on the hot side in the water experiment;the Fanning friction factor decreases with the increase of the Reynolds number on the hot side;both the thermal factor and the area quality factor decrease with the increase of the Reynolds number,and are 40% and 35% higher than the shell-and-tube heat exchanger under the same condition.When using lubrication,the heat transfer,heat transfer coefficient and pressure drop of the heat exchanger also increase with the increase of the volume flow on the hot side;the Fanning friction factor decreases with the increase of the Reynolds number on the hot side;both the factor and the area quality factor decrease with the increase of the Reynolds number on the hot side,and are 1.5 times higher than the shell-and-tube heat exchanger under the same condition.The lubrication side is the main thermal resistance side,which is also the focus of optimization.Then,a multi-V-corrugated plate heat exchanger model with complete double-channels and inlet-outlet and diversion channels was established,and the influence of the number of different V-corrugated shapes on the flow and heat transfer characteristics of the plate heat exchanger was studied.The numerical analysis results show that with the increase of the number of V-corrugated in the plate heat exchanger,the fluid between the plates gradually changes from a crisscross flow to a meandering flow,and when the number of V-corrugated is 5,the flow state is a complete meandering flow.The pressure drop,the Fanning friction factor and the Nusselt number increase with the number of V-corrugated.And the comprehensive performance analysis indicators show that the overall performance of the plate heat exchanger is better than the other three plate heat exchangers.Finally,the field synergy principle and the enthalpy transfer theory are used to conduct in-depth theoretical research on multi-field coupling and energy quality in the plate heat exchanger.The results show that the number of field synergies of the plate heat exchanger increases with the increase of the number of V-corrugated.The angle ? between the temperature gradient and the velocity vector becomes smaller with the increase of the number of V-corrugated,and a smaller angle ? will be generated better heat transfer.The efficiency of the plate heat exchanger increases with the increase of the number of V-corrugated,indicating that the transfer efficiency of useful energy is improved.This not only comprehensively considers the synergistic effect of the different fields of heat exchange and flow process of the plate heat exchanger,but also considers the energy quality transfer of the flow heat exchange process of the plate heat exchanger.