Optimization And Analysis Of Steam Condenser Based On CFD Method

As one of the significant auxiliary component of the steam turbine in a power plant, the performance of the condenser influences the safety and economic efficiency of the unit. The major duty of design and optimization of the condenser is designing and optimizing the arrangement of tube bundle and the structure of the flow field in the condenser according to the characteristics of heat transfer coefficient, steam flow resistance in the shell field and cooling water flow resistance,load of the vacuum pump. This paper aims to identify the influence of the cooling water temperature and flow distribution to the flow and heat transfer of the steam and air mixture in the shell field, and provide theoretical and effective reference to the design and optimization of the condenser.This paper used porous media model to simplify the tube bundle area in the flow field.The length of the tube bundle was reduced and resistance coefficient was based on the reduced length in order to optimize the porous media, which reduced the flow expansion of cooling water in the porous media. A 3-dimensional CFD model of the condenser’s flow field was set. This research used porous media model and introduced mass sink and moment sink model to simulate the flow and heat transfer process of air-steam mixture in tube bundle area and set up a 2-dimensional condenser shell field model in the shell field simulation.This paper used commercial CFD Fluent software to solve the above model. In the numerical simulation of flow field, flow resistance of the condenser cooling water in the flow field and flow distribution of cooling water in tube bundle area were studied. Taking flow distribution into consideration, the coupling steam-water calculation is conducted according to the results of the numerical simulation in flow field. This research also figured out details about the flow and heat transfer process of air-steam mixture in the shell field and analyzed the results of numerical simulation, also discussed the effect of cooling water flow distribution on low and heat transfer process in the shell field.Finally, considering inlet temperature changes of cooling water caused by environmental changes, this paper used the coupling steam-water model above to conduct numerical simulation about the working condition of cooling water inlet temperature and analysed changes of flow resistance, flow distribution of cooling water in flow field, inlet steam pressure,flow resistance, heat transfer coefficient and heat transfer temperature in shell field caused by the change of cooling water temperature.