Dynamic behavior of an absorption heat pump

Abstract A dynamic model of an absorption heat pump has been developed and verified with an existing commercial machine. Modelling was based on the instationary heat and mass for each component of the heat pump. Partial differential equations which emerged were converted to ordinary differential equations by discretization with respect to space. Then, all differential and algebraic equations were solved in parallel by a suitable differential and algebraic equations systems solver. In this paperthe major results are presented. They include a brief analysis of the steady state of the heat pump at full load as calculated and compared to measured data. To exemplify the dynamic behaviour of the system a stepwise change of the flow rate in the heat source circuit of ±20% and a linear increase of 5 K within 300s in the inlet temperature of the heat sink circuit were applied both to the model and to the real machine. All results show good agreement. Remarks concerning simple control of the heat pump under consideration conclude the paper.