Direct-coupling simulation of thermal-hydraulic and stress analysis in a Cross-Wave primary surface heat exchanger

Fluid flow with heat transfer in the Cross Wave (CW) primary surface channels may cause an external stress in the plate due to the non-uniform pressure on the plate surface and nonuniform temperature inside the plate. The plate construction can be deformed under this external stress, which will affect the flow of the fluid by changing the channel dimensions and thus affect the temperature fields. To solve the multi-physical field problem, a direct-coupling simulation method of thermal-hydraulic and stress analysis in a Crow-Wave (CW) primary surface heat exchanger is presented in this paper. The method is based on the commercial code STAR-CD and ABAQUS, and an in house procedure is added to accomplish the direct-coupling simulation in a transient process between thermal-hydraulic and stress modules. Due to the complicated simulation of fluid flow and heat transfer in a two-coupled CW fluid channels in which each channel is separated by the plate (original model) in the CFD (Computer Fluid Dynamics) procedure, an alternative CFD model that is different from the original model is constructed to enable the CFD analysis. The detailed geometry of the original mode is generated in the CAE (Computer Aided Engineering) procedure. A data transition program is developed to control and transform analysis data between the CFD model and the CAE model. The coupling relationship of surface pressure, temperature and the material stress in the CW primary surface heat exchanger is uncovered. The results indicates that the high thermal stress and large displacement about 2.26×10³ MPa of stress and 8.28×10^-2 mm of displacement are generated at the beginning of time steps. Therefore, more attention should be paid during the starting up and emergency stop process due to the excessive build of stress during the transient conditions.