During the course of an hypothetical severe accident in a Pressure Water Reactor (PWR), hydrogen can be produced by the reactor core oxidation and distributed into the reactor containment according to convection flows, water steam wall condensation and interaction with the spraying droplets. In order to assess the risk of detonation generated by a high local hydrogen concentration, hydrogen distribution in the containment has to be known. The TOSQAN experimental program has been created to simulate typical accidental thermal hydraulic conditions. TOSQAN facility is a large vessel (7m3) suitable for optical diagnostics such PIV, LDV and Spontaneous Raman Scattering which are already operational on it.
In order to characterise the heat and mass transfers between the sprays droplets and the atmosphere we interest in measuring non intrusively the mean droplets temperature. The issue to achieve this measurement is to develop the Global Rainbow Refractometry.
Our work on the global rainbow refractometry is presented in this paper that is divided into four parts. The first part is devoted to explain the principle of the technique, and how this phenomenon occurs. In the second part we will present the program we developed and the simulations we realized in order to quantify the effect of different parameters on temperature and diameter measurements (droplet non sphericity, spray granulometry (figure1), size-temperature relationship). In the third part we will present our experimental setup that is devoted to be implanted onto TOSQAN, and finally we will present our global rainbow results (figure 2) on a full cone spray.
Ce travail a été fait en colaboration avec CORIA.