Dynamics of a heat transformer working with the mixture NaOHH2O

The model described in the paper is based on the balance equations for mass and energy for the different apparatus such as absorber, generator, evaporator, condenser and solution heat exchanger. It simulates a heat transformer process and ensures calculations not too time-consuming and much faster than in real time. With the aid of the model the transient behaviour of a heat transformer working with the mixture NaOHH₂O is examined. For steady state operation the simulations agree well with experiments on a pilot plant. With NaOHH₂O as working substances high COPS up to 0.49 were obtained with this heat transformer. For unsteady state operation the deviations between experiments and simulations were slightly higher than those for steady state. The model nevertheless predicts the transient behaviour with a satisfying accuracy. Also the startup and shutdown behaviour of a heat transformer was investigated under different conditions.