Three Dimensional Numerical Simulation Of A Power Plant Condenser Coupled With Both Sides Of Shell And Tube

At present,most of numerical simulation of the surface condenser was based on the method and analysis of the models established separately from both sides.The simulation of the shell side was usually based on the assumption that the cooling water velocity is uniform.The uneven velocity distribution was seldom considered.The paper has proposed a new simulation scheme of the condenser,in which the porous media calculation is established separately on both sides.On the basis,using the fluent secondary development platform to develop the self-defined program to inject the water velocity distribution of the tube side into the shell side.In addition,a calculation code of cooling water temperature in porous media has been developed to realize the three-dimensional simulation coupled with both sides of shell and tube.Finally,a 600 MW surface condenser is taken as the experimental object to verify the effectiveness and feasibility of the simulation scheme.The porous media area which is used to simplify the tube bundle area is shorten the length along the flow direction to reduce the lateral diffusion of cooling water.On this basis,the tube side three-dimensional model of the condenser is established.The porous medium area of the shell side is also used to replace the tube bundle area,and the condensation and flow resistance of water vapor in the tube bundle area are equivalent to the distribution mass sink and distribution resistance.Since the two sides are established separately,the grid is not uniform.The center point coordinates of the grid at the bottom right corner of the porous media are selected as the relative origin to modify all grid coordinates.According to the Lagrange interpolation algorithm,the water velocity distribution is linearly injected into the porous media on the shell side.The self-defined program is developed to realize the function of importing cooling water velocity from the tube bundle area to the shell side.The algorithm of cooling water temperature in porous media on the shell side is developed.With the process of fluent iteration,the water temperature is continuously repaired.In the joint simulation of velocity and temperature of cooling water in the shell side,the three-dimensional characteristics of thermal parameters along the cooling water process are discussed.In the end,the three-dimensional shell side model is used to change the temperature of the cooling water inlet caused by environmental factors.The qualitative and quantitative research on off-design parameters of the shell side has been done to discuss inlet pressure,flow resistance,heat transfer coefficient,condensation rate to provide theoretical basis and effective reference for the design optimization of the surface condenser.