Evaluation of a power generation system that integrates multiple Kalina cycles and absorption heat pumps

Small temperature difference power generation technology using a combined heat pump cycle and a Kalina cycle is predicted to reduce greenhouse gas emissions and the use of fossil fuels. It has been reported that an absorption heat pump cycle can be used as a chiller unit in the Kalina cycle to improve thermal efficiency and create an efficient cogeneration system. However, most of these studies have been performed for power generation systems of several tens of kW class or larger; there have been no studies on small temperature difference power generation systems. There is also no research on the application of absorption heat pump cycles to improve the quality of the heat sources of these systems. In this paper, we propose an integrated system that comprises an absorption heat pump cycle and Kalina cycle for small temperature difference power generation to lower the temperature requirements of the heat source. We evaluate its power generation performance and economic efficiency. The results show that our proposed integrated system can improve power generation performance by up to 81% compared to the conventional Kalina cycle, and is also more economical than the conventional Kalina cycle when applied to heat sources above 353 K.