Community Research and Development Information Service - CORDIS


Computational models are developed of the processes occurring in a tank reactor containing a multi-component liquid mixture, in which an exothermic chemical reaction occurs, in order to size the emergency relief system required in case of accidents due to thermal runaway. The present paper discusses the main features of a modelling approach adopted for describing the multicomponent two-phase flow phenomena governing the venting process. Illustrative calculations are also presented which highlight the effects of vent line location, the relative velocity between the phases, the vapour-liquid equilibria of the multicomponent two-phase system and an exothermic first order chemical reaction. The calculations are restricted to systems characterised by a homogeneous chemical reaction in the liquid phase of which all components are miscible. Major attention is given to the multicomponent two-phase fluid behaviour in the vessel. In modelling the in-vessel fluid behaviour an attempt is made to separate as far as possible the physical, physico-chemical and thermokinetic phenomena associated with the multicomponent phase-equilibrium and with the exothermic liquid phase chemical reaction from the phenomena pertaining to the two-phase fluid dynamics. This enhances model transparency and makes optimal use of transient two-phase flow modelling techniques developed for single component two-phase systems in the frame of the Light Water Nuclear Reactor Safety Programme.

Additional information

Authors: FRIZ G, JRC Ispra, Ispra (VA) (IT);NIJSING R, JRC Ispra, Ispra (VA) (IT);DUFFIELD J S, JRC Ispra, Ispra (VA) (IT);MEHR K, JRC Ispra, Ispra (VA) (IT)
Bibliographic Reference: Paper presented: 1989 European Two Phase Flow Group Meeting, Paris (FR), May 29-June 1, 1989
Availability: Available from (1) as Paper EN 34866 ORA
Record Number: 198911152 / Last updated on: 1994-12-01
Original language: en
Available languages: en