Numerical Simulation Study on Flow Heat Transfer and Stress Distribution of Shell-and-Tube Superheater in Molten Salt Solar Thermal Power Station

Abstract

The flow heat transfer and stress distribution of the shell and tube superheater of the steam generation system in a 50 MW molten salt tank solar thermal power station are studied by numerical simulation, and the influence of the flow pattern of molten salt and water vapor in the shell-and-tube superheater on the heat transfer efficiency and stress distribution under the heat–fluid–solid coupling condition is deeply studied. When the water vapor is located on the tube side of the superheater, the molten salt is located on the shell side, and the counterflow is used in the superheater, the water vapor outlet meets the inlet temperature of the steam turbine, and the heat exchange efficiency of the superheater can reach 94.2%. The optimum inlet temperatures of molten salt and steam in the superheater are 563 and 345◦C, respectively, and the optimum flow rate of molten salt at the inlet of the superheater is 2.5 m/s. Compared with the stable condition, the heat exchange efficiency can be increased by 2.9%, the equivalent stress value is reduced from 335.63 to 312.60 MPa, and the deformation is reduced by 0.48 mm.