Calorimetric equipment with time-evolution parameters measurements and modelling in flow and mass-varying calorimetry

Abstract

The injection calorimeters are used to evaluate thermodynamic properties of the mixtures and solutions. TheH i E partial molar excess enthalpies or theL υ, i relative apparent molar enthalpies against mole fraction are available from an appropriate signal processing of the calorimetric curves. An evolution of the thermal properties of the calorimetric vessel are associated with the injection process. Description of calorimetric equipments by means of a localized—constants model (RC analogy) allows us to systematize and to extent these systems into time dependent situations. Experimental measurements based on Joule effects and associated mathematical analysis permits to determine the absolute limits of the dynamic behaviour of these equipments from several standard and easily experimental parameters (sensitivity, noise level, τ1 the first time constant, sampling period). Models and experimental study provide an estimation of the corrections in order to compensate the evolution of the physical characteristics of the device.