原子炉建屋内運転階の新換気空調設備の開発

抄録

A heating, ventilating and air conditioning (HVAC) system is installed on the operation floor of a BWR reactor building for temperature control and dust protection in work areas. In the current HVAC system, it is necessary to ensure that its exhaust ducts do not interfere with other structures and pipes, since pipings are buried under the floor.
In this study, air velocity and temperature distributions and heat removal rate were analytically and experimentally investigated, and duct arrangements without the buried exhaust ducts were evaluated. In the analysis, a three-dimensional thermal hydraulic analysis computer program for incompressible viscous fluid was applied, and a laminar flow model and slip condition on the wall surface were used, based on a comparison of calculated results with measured ones. In the experiments, a one-twentieth scale model was used, and the temperature distribution was measured by thermocouples. Furthermore an airflow distribution was visualized and three-dimensional flow path lines were obtained by computer-aided image processing. The proposed HVAC system uses a rising current of air on the hotter surface of the reactor refueling pool and spent fuel pool, and exhausts air through exhaust ducts on the ceiling. Consequently, it is confirmed that the new HVAC system can be realized, which increases the removal heat capability on condition of the same ventilation rate as the current system.