Optimization And Experimental Study Of Inertial Separation Carbon Stripper

Chemical looping combustion is a novel technology in accord with"double carbon"policy and promoting energy conservation and emission reduction,which has broad application prospects.However,one of the urgent problems in this technology is the mismatch between the gasification of solid fuel and the gas-solid reaction,resulting in the consumption of unconverted char particles into the air reactor,which decreases the carbon capture efficiency of solid fuel chemical looping combustion system.To solve this problem,it can use carbon stripper to separate the unconverted char and return it to the fuel reactor for the second reaction,which is recognized by most scholars.However,currently most of carbon strippers have limited performance and lack of targeted and mechanistic research.Based on the above problems,in order to facilitate the independent research and optimization of carbon stripper to improve its performance,this research designs and constructs an independent carbon stripper system,and innovatively adds active adjustment method,which forms a visual carbon stripper device with active adjustment method for experimental research.In addition,the feasibility test and reference condition test verify the feasibility of the system.Based on the cold test device,the full-field pressure distribution of the test device is studied through the pressure monitoring system,and the effects of main gas flow,simulated air reactor cross flow,longitudinal position and active gas flow are also researched.The test results show that the system operates stably with a low pressure drop of carbon stripper,and each component connects with smooth pressure.With the increase in main gas flow,the separation efficiency of PVC particles increases,while that of quartz sand particles decreases slightly.Increasing air reactor cross flow moderately can improve the separation efficiency of PVC particles,but it is prone to marginal effects.When active gas longitudinal position changes in a certain range,it has little effect on binary particles separation efficiency.Active adjustment gas can significantly improve the separation efficiency of PVC particles,and it’s more obvious with the increase in gas flow.Based on CFD,it uses double Euler model and DDPM model coupled with DEM to analyze the continuous phase and the discrete phase flow field separately,which constructs the numerical calculation model of carbon stripper for feasibility verification by cold test data.It simulates the flow field and analyzs the binary particle separation mechanism in carbon stripper under the reference condition.Also,it carries out the research on the structural factors such as the length and angle of baffle,and the length and inclination of deflector.With the deepening research on the active adjustment method,it finally forms the structure-optimized carbon stripper with active adjustment method.The simulation results show that under normal working conditions(solid flux G_s<200 kg/m²·s,air reactor cross flow D_AR≥-5 m³/h)it can keep PVC particle separation efficiency of more than 90%and quartz sand particle separation efficiency of 100%.Under some extreme working conditions(G_S is 200～300 kg/m²·s,D_AR is-15～-5m³/h),it can still keep the PVC particles separation efficiency of more than 75%and the quartz sand particles separation efficiency of nearly 100%.On the basis of cold simulation,by using the double Euler model and the DDPM model to analyze the continuous phase and discrete phase flow field separately,it establishes a three-dimensional numerical model of circulating fluidized bed chemical looping combustion reactor coupling with gas-solid flow and chemical reaction based on the improved carbon stripper coupled with fuel reactor.It predicts the specific operation of the improved carbon stripper under the thermal conditions,and shows the significant characteristic parameters such as gas-solid flow,component distribution,fuel conversion and carbon capture efficiency.Finally,it analyzes the performance of carbon stripper under hot conditions through the study of the influence on variable solid flux,which achieves the supplement and expansion of tests.