The IR-Large-Temperature-Jump method: Determining heat and mass transfer coefficients for adsorptive heat transformers

Abstract

The design of adsorptive heat transformers (adsorption heat pumps and chillers and adsorption thermal energy storage) requires knowledge on the heat and mass transfer resistances in adsorbents. However, heat and mass transfer cannot be distinguished in conventional experimental setups, since only pressure data is available. In this work, we present an approach to distinguish and quantify heat and mass transfer resistances in adsorbents. For this purpose, we extended the Large-Temperature-Jump method (LTJ) with an infrared camera (IR) and combined the new IR-LTJ method with dynamic modeling. The IR camera determines the surface temperature of the adsorbent as an additional information. Subsequently, the data from the IR-LTJ setup is used in dynamic models to quantify time-resolved heat and mass transfer coefficients. We conducted experiments for one layer of granulated Fuji Siogel for use in an adsorption chiller with the temperature set 10/30/70. We show that the suggested method is able to determine heat and mass transfer coefficients.