Heat And Mass Transfer Analysis Of Cryogenic Liquid With Water And Experimental Investigation

The research problem of the heat and mass transfer of the cryogenic liquid and water is raised in this thesis. The cryogenic liquid change liquid state into gaseity during the period , buoyancy influence and gaseity condensability result in problem being so complex. Some assumptions are made to simplify this problem in theory.The problem of the heat and mass transfer of the cryogenic liquid and water is analyzed. A front-tracking method is used to track the moving interface and speculate the existing length of the cryogenic liquid column in water. The process and characteristics of heat transfer between cryogenic liquid and water are different under different water pressure. The models of heat and mass transfer under supercritical and normal water pressure are established. The numerical calculations based on the model are done, the results show the temperature field of the cryogenic liquid and the existing length of the cryogenic liquid. The mass transfer coefficient of interface in normal environment is educed. The existing lengths of five millimeters diameter's liquid nitrogen column under supercritical and normal water pressure are about one and two centimeters, other result of numerical calculations indicates the feasibility of draining the cryogenic liquid directly into water too.The experiment of draining the near-atmospheric liquid nitrogen directly into near-atmospheric pressure water is done. Some pictures of the flow patterns and some experimental data about temperature during draining process are gotten and analyzed. The temperature measurement data are qualitatively analyzed. The estimate value and the observed value of the existing length of the liquid nitrogen column are compared. The estimate value accords basically with the observed value. The experiment of draining the enhanced pressure liquid nitrogen directly into near-atmospheric pressure water is done for the first time. Some pictures of the flow patterns and some experimental data about temperature, the draining process and the experimental phenomena are gotten and analyzed. The existing length of the liquid and gas nitrogen column is much longer than that of near-atmospheric liquid nitrogen. The result indicates the feasibility of draining the cryogenic liquid directly into water. This thesis gives a project for supercritical pressure drain experiment, the experiment system, equipment are designed.The research validates the feasibility of draining the cryogenic liquid directly into water and offers the basis of designing the draining device. The heat transfer model and analyse of mass transfer in this thesis have important reference value to establishing the complex models that consider comprehensively heat transfer, mass transfer and flow.