Two-Way Fluid Thermal Solid Interaction Numerical Analysis Of Steam Generator Heat Transfer Tube

The steam generator heat transfer tube will deform under the action of pressure load and temperature load of primary side and secondary side.The deformation of the heat transfer tube will in turn affects the flow and heat transfer characteristics of primary side and secondary side.Therefore,it is of importance to study the tube stress and tuhe strain and the coupled heat transfer under the mutual interaction of solid domain and liquid domain.In this paper,based on the similarity principle,a simplified physical model without tube support plate of the Daya Bay nuclear power plant steam generator is established.With the help of Workbench platform,CFD software CFX and CSD software Transient Structual were connected to achieve two-way data transfer between fluid domain and solid domain,in order to achieve the single phase flow and two phase flow two-way ftsi of steam generator heat transfer tube under three different operating condition.Variation of thermal hydraulic parameters and heat transfer tube displacement,mechanical stress,thermal stress and total stress will be analyzed based on the calculation.For the preheating section,under the action of pressure,or under the action pressure load and temperature load,the heat transfer tube deviates to the third quadrant.Along the height direction,the decrease of temperature difference between the inside and outside of the heat transfer tube leads to the decrease of thermal stress,the mechanical stress and the total stress increase first and then decreases.Stress is vector,so the total stress is not equal to the algebraic sum of thermal stress and mechanical stress,average thermal stress.The thermal stress,mechanical stress and total stress along the height direction decrease with the decrease of operating load.Along the wall thickness,the thermal stress decreases first and then increases,the mechanical stress decreases gradually,the total stress increases gradually.The thermal stress,mechanical stress and total stress along the wall thickness decrease with the decrease of operating load.Along the circumferential direction,periodic change of temperature difference leads to the periodical change of thermal stress,the mechanical stress and thermal stress are symmetrically distributed with respect to the direction of deviation,the thermal stress,mechanical stress and total stress along the circumferential direction decrease with the decrease of operating load.For the two phase boiling section,liquid phase of secondary absorb heat energy and vaporize.Along the flow direction,the liquid temperature of the secondary side increases firstand then decreases gradually,and ultimately remained unchanged.With the decrease of operating load,the heat transfer decreases,the position of maximum liquid temperature under the 100%,70% and 50% operating load is 0.25m?0.45 m and 0.6m respectively.Under the action of pressure,or under the action pressure load and temperature load,the heat transfer tube deviates to the third quadrant.Along the height direction,mechanical stress and total stress increase first and then decrease,with the decrease of operating load,mechanical stress and total stress decrease at the same height.Along the circumferential direction,thermal stress fluctuates and has no obvious regularity,mechanical stress and total stress are symmetrically distributed with respect to the direction of deviation.The distribution regularity of mechanical stress and total stress at the cross section near fixed support are not same to that at the cross section far away from fixed support.With the decrease of operating load,mechanical stress and total stress at the same angle decrease.