Numerical Simulation Of Heat And Mass Transfer Of Direct Contact Flue Gas Condenser

Carbon dioxide is one of the major greenhouse gases who have contribution to the greenhouse effect.The problem of environment because of excess emission of greenhouses gases takes a severe challenge to human being.Oxygen-enriched burning technology is one of the technologies who can capture and store the carbon dioxide.In this system,the effect of direct contact condenser is to condensate the flue gas and wipe out the vapor of flue gas produced in burning process.As an application apparatus,DCC has the advantages of low cost and small.But the principle of DCC is now at research.The thesis uses the commercial computational fluid dynamics software Fluent to simulate the condensation process between the flue gas and cold water in DCC.The consequence of the simulation is in accordance with the result in experiment of research group.The thesis also simulates the heat and mass transfer process in different parameters and researches the influence of temperature of colder water,the degrees of spray and the diameter and height of the DCC to the heat-transfer characteristic.Comparing the results in different operating environment,author find that both decreasing initial temperature of colder water and increasing the degrees of spray can increases the condensation rate.The thesis get the result when the diameter of DCC is 2.4m,2.6m,2.8m and 3m,and also the result when the height of DCC is 3m,5m,7m,9m and 11 m.According to the analysis to the heat-transfer characteristic of DCC in different heights and diameters,the thesis finds that the mole fraction of vapor in DCC whose diameter is 3m,height greater than 11 m or diameter is 3.5m,height greater than 12 m,is satisfy with the requirement.The research can provide a reference to the size design of DCC in industry.