The Study Of Heat Transfer Influencing Factors In The Shell Side Of Power Plant Condensers

Condenser is an important auxiliary device for turbine unit. There are many effects thatinfluence the heat transfer of condensers. The experimental and numerical methods are twomain measurements to analyze the heat transfer characteristics inside of condensers. In orderto study the various heat transfer influencing factors in the shell side of condensers, aquasi-three-dimensional approach with porous media concept is developedThe quasi-three-dimensional algorithm can very well simulate the fluid flow and heattransfer distribution inside condensers as well as the the three dimensional heat transfercharacteristics along the cooling water direction. The condenser is divided into several sectorsalong the axial direction. A two-dimensional numerical model is developed in each sector. Thethree-dimensional heat transfer effects are taken into account by a series of two-dimensionalcalculations. The heat transfer simulations are also compared by dividing the condenser indifferent sectors.The heat transfer performance influencing effects are studied in seven ways: inletcooling water mass flow and temperature, inlet steam mass flow, inlet air mass fraction,fouling heat transfer resistance, turbulent viscosity and grid number. The inlet cooling watermass flow, inlet cooling water temperature and inlet steam mass flow have a direct effect onthe heat flux, the average overall heat transfer coefficient and steam condenser mass flow. Theair in the mixture gases will greatly reduce the heat transfer in the shell side of condensers.Fouling resistance may decrease the overall heat transfer coefficient, increase heat transfertemperature difference and decrease vacuum degree. When the turbulent viscosity is sometimes of molecule viscosity, it can well simulate the heat transfer in condensers. When thegrid number can be able to describe shape of the physical model, the grid number has littleinfluence on the heat transfer, and the calculated precision is very good. But the grid numberhas large influence on the real-time computation on the heat transfer.