Numerical and Experimental Investigation on Influence Factors of the Leakage Rate for a Large-Size Pressure Gate With Rubber O-Ring Sealing Structure

Leakage of these hatches with large sizes must be strictly controlled in any operating conditions for the safety of a nuclear power plant. In this work, an effective numerical approach to construct a leakage prediction model to analysis the tightness performance of the rubber O-ring sealing structure of a large-size pressure gate was proposed. The model is built based on the transport theory of the porous media, and combined the micro roughness effect and the macro mechanical behavior on the leak rate, which were obtained by using Finite Element Method (FEM) simulation. A series of experiments are designed to validate the results predicted by this model. Experimental results are in good agreement with that predicted by the proposed model, which verifies the rationality and preciseness of the model. Based on the model, a further research to understand the effect of various factors on the leak characteristics was made. The results show that the tightness performance of the O-ring with an elliptical trapezoid cross-section is better than that with a round cross-section. And the rubber with lower hardness can provide a better sealing capability during accidents (corresponding to the inside pressure increasing conditions).The new model is very helpful in the optimum design of a rubber sealing structure.