Numerical and experimental investigation of the dynamic performance of absorption heat transformers under different solution conditions.

• Experimental rig and dynamic model of absorption heat transformers were built. • The model was calibrated and validated with experimental data. • The RT and temperature oscillations were reported when solution conditions change. • The fitted formula between the RT, temperature oscillation, and TS were presented. • Recommendations were given to reduce temperature oscillations and shorten RT. An experimental investigation and dynamic simulation of vertical falling-film LiBr/H 2 O absorption heat transformer systems have been reported in this paper. The established 20 kW experimental equipment was used to test the dynamic performance and verified the mathematical model. The experimental results show that there is a time delay between the input heat and output useful heat, and the time delay of the experimental results is 115 s. The simulated results show that the response time increases with increasing total solution mass and increases with decreasing solution mass flow rate. The temperature flow oscillations decrease with increasing total solution mass and decrease when the solution mass flow rate decreases. The response time of the absorption heat transformer is almost linearly related to the characteristic time of solution storage, which provides guidance for the operation and prediction. By adjusting the total solution mass and solution mass flow rate, theoretically the response time can be reduced to approximately 150 s. The temperature change range of the absorber outlet water can be controlled within 0.5 K by reducing the solution mass flow rate. The total solution mass and mass flow rate should be reduced, which can reduce temperature flow oscillations and shorten the time delay. The response time can be predicted by combining the experimental data and the linear relationship of the response time for any absorption heat transformer. [ABSTRACT FROM AUTHOR]