Simulation study of a dual facade-integrated adsorption system for demand responsive solar cooling of buildings

Abstract

The electricity demand for space cooling will increase significantly over the coming decades. At the same time, building related CO2-emissions are to be reduced for climate protection. In this context, an innovative facade-integrated adsorption system for solar cooling of buildings was introduced and developed at the University of Stuttgart. In our previous work, a detailed simulation model of the system was presented, which is significantly extended in this work to a multi-adsorber system, integrated into two separate facades. For the first time, this allows us to investigate realistic cooling scenarios of high practical relevance. The investigation encompasses novel operational modes and switching strategies that facilitate continuous and demand-responsive cooling. The simulations of a defined reference case yield continuous cooling rates of 54 W per installed square meter of adsorber facade. The demand responsive cooling mode is capable of meeting the cooling demand of a reference office building with a peak cooling power of 100 W per installed square meter of adsorber facade. Moreover, a thorough parametric study was conducted to evaluate the impact of geometry parameters and the adsorber orientations under the applied conditions. The results reveal that changes in compass orientation of the adsorber facade are meaningful and that a continuous cooling power level of 70 W per installed square meter of adsorber facade can be provided for almost 24 hours. The findings verify the viability of the extension to a multi-adsorber system and the proposed alternating operating modes.