Thermal Mixing Characteristics of Two Fluid Flows with Different Temperatures in a T-tube. Mixing Characteristics in a T-tube and Effect of a Downstream Bent Tube.

Abstract

Thermal and nuclear power plants have many T-tubes where a hot fluid and a cold fluid flow into each other and mix. An optimally designed T-tube can be used to shorten mixing time which can lead to more compact plants. We have experimentally investigated the mixing characteristics of hot and cold fluid flows into a T-tube. This paper shows the mixing distance, an analogy between thermal and mass diffusion, and the optimum condition for rapid mixing. We propose a T-junction arrangement using a downstream bent tube as a mixing promoter. The experiments so far clarify that the bent tube can best enhance mixing when the branch tube in the T comes from the opposite direction to the bend. For example, at the velocity ratio u/U=1. the bent tube can reduce the mixing distance from 35D to 8D and still achieve sufficient mixing.