Study On The Hydraulic Characteristics Of Electrochemical Descaling Reactor And Configuration Optimization Based On CFD

Electrochemical technology is used in more and more countries and regions in the field of water treatment because of its clean,non-polluting and low energy consumption characteristics.Therefore,this technology has been highly valued and researched in recent years,but most of the current research on electrochemical treatment technology focuses on the improvement of electrical parameters and the development of new equipment,and lacks research on the flow field distribution and hydraulic characteristics of electrochemical descaling reactors.And the reactor configuration is the main factor to determine its hydraulic characteristics.Therefore,the optimization of electrochemical descaling reactor configuration can help to promote the development of electrochemical descaling technology and realize the reasonable design of reactor in order to achieve the purpose of improving the reactor treatment performance.Firstly,the causes of scale and the principle of electrochemical descaling are explained,based on which the design parameters that can improve the descaling efficiency of electrochemical reactor and the hydraulic characteristics of the reactor are determined.The results show that increasing the electrolysis time and increasing the initial hardness of water samples can effectively increase the descaling rate;by comparing the descaling efficiency under different electrolysis time and initial hardness of water samples,the best operating parameters in this test range are obtained.Secondly,based on the folded plate electrochemical descaling reactor,the steady-state calculation of reactor flow was carried out by numerical simulation to study the reactor flow field distribution under different pole plate spacing and flow velocity.The results show that the flow field in the reactor is more reasonable with the decrease of the pole plate spacing and the increase of the inlet flow rate,i.e.,the flow state of the fluid is improved;meanwhile,the study shows that the dead zone in the reactor is mainly distributed on both sides of the pole plate,and a small amount is distributed in the corners of the reactor;the short circuit zone in the reactor is mainly distributed on the left side of the pole plate.In order to further study the reactor hydraulic characteristics,the residence time distribution of the fluid in the reactor was measured by the pulse tracer method on the basis of the steady-state flow field,and the residence time curve was obtained after the flow field reached the steady state.The flow field distribution,reactor flow pattern,backmixing degree and bad reactor flow were used as indicators to evaluate the reactor hydraulic characteristics,and the hydraulic characteristics of the reactor under different configurations were analyzed.The results showed that the PE number and model parameter N increased with the increase of plate height and decrease of plate spacing,and their maximum values were16.2 and 31.4 respectively,which indicated that the re-mixing in the reactor was reduced,making the reactor flow more similar to the advective flow;meanwhile,the maximum peak time increased,making it more similar to the average residence time,which could effectively enhance the reactor hydraulic performance,but these two changes would increase the reactor hydraulic properties,both changes will increase the pressure drop of the reactor and thus increase the energy loss,and the effect of reducing the pole plate spacing on energy consumption is more significant compared with increasing the pole plate height.Finally,the dead zone percentage in the reactor was quantitatively analyzed,and the reactor was optimized in combination with the energy consumption analysis.The results showed that the optimal configuration was achieved when the plate height was630 mm and the plate spacing was 103.56 mm without considering the energy consumption,and the optimal configuration was achieved when the plate height was630 mm and the plate spacing was 172.6 mm with considering the energy consumption.So far,the optimal reactor configuration and design parameters were obtained to realize the rational design and optimization of the reactor.This thesis provides a method for reactor configuration and optimization from the perspective of hydraulic characteristics,which can provide ideas for the design of similar reactor structures.