New approach to Tian's equation applied to heat conduction and liquid injection calorimeters

Abstract

In the calorimeters used for the determination of thermodynamical properties of liquid environments, the mixture takes place when injecting liquid in the mixture zone, this injection incorporates an additional calorific power that is a function of the volumetric heat capacity of the injected liquid and the injection flow. In this article, it is rewritten Tian’s equation including this additional power to relate correctly the experimental output to the mixture enthalpy. It is applied Tian’s equation, once it has been corrected, to two types of calorimeters: flow-microcalorimeters and isothermal titration calorimeters. In this second case, it has been taken into account the classical operating mode (titration) and the continuous liquid injection mode. Tian’s equation, completed with all the energetic terms additional to the mixture process, is of great interest for the scientific and academic community because it allows to explain, in a simple and effective way, the operation of these instruments.