Numerical Analysis Of Natural Circulation Flow And Heat Transfer Of 37 Rods Sodium Cooled Fast Reactor Experimental Components

Another significant disadvantage brought by the advantages of nuclear technology in the production of electricity is that it also generates a large amount of spent fuel,and the amount of spent fuel is growing rapidly worldwide.Because of its high radioactive hazard to the environment and society,the reprocessing of spent fuel has become an urgent problem.Because of its use of plutonium 239 as the main fuel,sodium-cooled fast reactors can produce uranium 238 by absorbing uranium 238 and form uranium 239 to realize the rapid proliferation of nuclear fuel.Depletion,which plays an important role in protecting the environment.Sodium-cooled fast reactors have high power density.In order to ensure their safety and reliability,it is of great significance to analyze the heat transfer and flow conditions under natural circulation conditions during the removal of accidental waste heat.This paper analyzes the experimental components of sodium-cooled fast reactors designed by similar theory for sodium-cooled demonstration fast reactors.Taking 37-rod wire-wraps fuel assembly rod bundles as an example,the cross-section outlet temperature is initially obtained experimentally,and the friction resistance pressure drop calculation is performed.By selecting four turbulence models,Standard k-ε,RNG k-ε,Realizable K-ε,and SST k-ω,to compare parameters such as friction resistance and pressure drop,and select a suitable turbulence model to conduct low Reynolds number heat transfer and flow analysis under natural circulation conditions,so as to better The understanding of its natural circulation mechanism provides a reference for the design and optimization of sodium-cooled fast reactors.Numerical analysis shows that the RNG k-ε turbulence model has higher applicability.Numerical analysis of the model shows that under heating conditions,the temperature distribution of the internal sub-channels of the fuel assembly is significantly higher than that of the external sub-channels;and the density field distribution On the contrary,the density of the internal sub-channel is lower than the density of the external sub-channel.In the flow field distribution,the axial velocity of the internal sub-channel is significantly higher than the axial velocity of the external sub-channel,and the high velocity region changes periodically with t he change of the winding angle;The transverse velocity near the wire is relatively strong,which plays a good role in mixing the flow field and temperature field.