The construction of efficient electrolysers requires a detailed knowledge of the mass flows, currents and temperatures in the cell. The paper describes three successive models designed for modelling transfers in an industrial electrolysis cell for fluorine production. The conservation laws for charge, mass and energy are approximated by use of a Galerkin finite element code. The solution of coupled transfers is necessary to describe the thermal behaviour of the cell. The method used here may be extended to the modelling of other electrochemical cells.