Numerical investigation on heat transfer enhancement of helically coiled tube with corrugation in intermediate heat exchangers

The heat transfer effect of intermediate heat exchanger (IHX) is crucial to the non-electrical application of High-Temperature Gas-cooled Reactor (HTGR). Therefore, the present study numerically investigated the heat transfer and pressure drop characteristics in helically coiled tube with two different kind of corrugations in IHX. The simulation results indicate that the existence of corrugation destroys the development of boundary layer, increases the turbulence intensity and strengthens the heat transfer process. Within the Reynolds number studied, the heat transfer augmentation for tubes with spirally and transversally corrugation are about 1.04-1.08 times and 1.30-1.34 times, respectively. While the friction factors are about 1.10-1.13 times and 1.25-1.29 times compared to the smooth tube. The overall heat transfer performance of the tube with corrugation is improved and the improvement for transversally corrugated tube is better. The value of performance evaluation criterion (PEC) could be up to 1.25. Subsequent studies will take the effect of structural parameters into account for further optimization. (author)