Residential and industrial buildings equipped with a ventilation system are complex facilities, where heat and mass transfers could occur according to the operating conditions. In order to study these mass transfers, a methodology has been developed to reduced-scale experimentations for non isothermal flows study. This methodology has been numerically validated, and then applied to a standard configuration, representing of the ventilation systems operating principle which are encounter in the nuclear field.
The wind and the thermal phenomena influences on the mass transfers inside this configuration have been studied in the Jules Verne climatic wind tunnel of the CSTB for various operating ventilation system situations (normal operating ventilation system, stopping ventilation or protection rate of productivity) and scenarios of heat supply. These thermal sources can be generated by an industrial process or a fire. They have been reproduced experimentally with a helium injection. The effects of the heat sources coupled or not with wind on loss of building containment were highlighted and analyzed.
The reliability of the zonal code SYLVIA, used notably to support safety assessment in nuclear buildings, has been analyzed from these experimental results. The modelling of the physical phenomena experimentally observed has been validated. The leakage flowrates reversals have been retrieved with the SYLVIA code. A comparison between the calculations where the heat source has been simulated with a helium injection and with a thermal power permitted to observe the mass injection effect has been caused by the helium on the pressures, the flowrates and the temperatures.