Analysis of a directly fired small-scale absorption heat pump with solution recirculation and multiple feed of the desorber.

A natural gas fired ammonia/water absorption heat pump for heating applications with a maximum heat output of 18 kW was characterized experimentally and analyzed by means of simulations. Several improvement concepts for the heat pump cycle are implemented in this device, including solution recirculation in the absorber and the generator and a second feed of cold rich solution to the rectification column. Efficiency figures are presented for both part load conditions and different heat sink and source temperatures. Furthermore the influence of the cycle improvement methods on the efficiency as well as their interactions with each other was examined. Some of the heat exchangers of the heat pump are characterized by means of their UA value and their heat exchanger effectiveness. Simulative parameter studies were conducted in order to gain a deeper understanding of the efficiency influencing factors.

本研究针对一款最大热输出为18 kW、应用于供暖场景的燃气式氨-水吸收式热泵开展了实验表征与模拟分析。该热泵装置集成了多项热泵循环改进方案，具体包括吸收器与发生器内的溶液再循环，以及向精馏塔二次供给冷浓溶液。研究给出了该热泵在部分负荷工况及不同热源、热汇温度下的效率性能数据。此外，还考察了循环改进方法对热泵效率的影响，以及各改进方法间的相互作用。针对该热泵中的部分换热器，通过其UA值与换热器效能完成了特性表征。为深入理解效率影响因素，本研究开展了模拟参数化研究。