Abstract:

Open sorption heat storage is a novel technology for space heating in buildings driven by solar energy, industrial waste heat or off-peak electricity, which can effectively ease energy stress and reduce the electric load. However, its large-scale applications are hindered by the lack of accurate predictions of the output performances during the discharging process. In this study, we explained how the entrance, motion, and exit processes of the "reaction wave" (the moving reaction section with a constant speed) directly lead to the increasing, stable, and decreasing output temperature curve. The theoretical formula for the lasting time of the stable process was given. Moreover, zeolite 13X, which has been fully used in open sorption heat storage reactors, was chosen as the sorbent to study the main influencing factors on the output performance. Accordingly, an observation device based on an infrared camera is designed and established. The changes in the wave shape and movement of the reaction wave were obtained from calculations based on the recorded sorbent temperature inside the reactor during the whole sorption process. Moreover, the influences on wavelength and wave speed of the relative humidity, air velocity, and the particle size of zeolite 13X were investigated. The calculated and measured values of the lasting time of the stable output process were compared. The results could contribute to designing reactors using zeolite 13X.

Key words: sorption heat storage, reaction wave, wavelength, wave speed, stable output