Abstract
The heat flux of the tube bundle on the shell side of the steam generator is non-uniform and the experimental research in this field is mainly carried out in the aspect of uniform heating. So it is necessary to investigate its influence on heat transfer conditions. In this paper, the heat transfer characteristics of a transversely non-uniform heating tube bundle channel were investigated experimentally. The experimental tube bundle was non-uniform heating and could be equally divided into hot side and cold side. The experiments were carried out with various inlet conditions. During experiments, the fluid temperature distribution in the channel and the heat transfer coefficient variations of tube bundle were obtained. The result showed that under the influence of non-uniform heating, the fluid in the channel flowed transversely in a circumferential motion from the hot side into the cold side. And the larger difference of tube bundle heat flux between the hot side and the cold side, the more obvious this circulation phenomenon was. Additionally, the circulation would lead to the transverse fluid mixing, which promoted the energy transfer in the transverse direction. Thus, this phenomenon affected the fluid temperature field in the channel and the tube bundle heat transfer conditions, which made the fluid temperature at a certain height in the cold side become higher than that in the hot side. And it made the heat transfer condition of the cold side tube bundle change from single-phase convective to saturated boiling due to this fluid temperature rise. This phenomenon will enhance the heat transfer in the cold side compared to uniform heating conditions.
