To be able to perform annual performance predictions of the sorption heat store, two new TRNSYS modules were developed. The first one calculates the current temperature and the state of charging of the adsorption material in the storage tank, the second module calculates the temperature and liquid level in the condensate storage tank. These modules were then used in a system simulation that includes a space heating system of a typical single-family low-energy house (defined in IEA — SHC Task 26). The design temperatures of the space heating loop were 35°C flow and 30°C return temperature. Figure 6 shows the modular layout of the TRNSYS model including the numbering of the different components used in TRNSYS. The model includes a standard flat-plate collector array that can be controlled to charge either the adsorption store or the condensate storage tank.

To validate the models, simulated and measured charging and discharging cycles were compared. In figure 7, a desorption (charging) process is shown. The measured solar energy gain which was used to charge the adsorption store (Q_Koll_a_o) and the measured energy drawn from the condensate storage tank for condensation were used in the simulation model as inputs. The model then calculates the temperature of the adsorbent (T_Ads) and the state of charging (x) of the adsorption store. The bold lines in the figure represent the measured data, the thin lines the calculated values. A very good agreement of the state of charging values can be observed whereas there are still differences of a few Kelvin between the measured and the calculated adsorbent temperature. Therefore small adaptations to the models will still be necessary to improve the agreement of the model with measured values.

SHAPE * MERGEFORMAT