中文摘要：

双效氨水吸收式制冷循环是将高温级的吸收热用于加热低温级发生过程的高效且较简洁的新型复叠循环。通过数学建模对双效氨水吸收式循环在热源温度、冷却水温度、蒸发温度和放气系数等变化条件下的制冷性能系数（COP）等指标进行了分析计算，对双效氨水吸收式循环与传统的单效循环和双级循环的制冷性能系数进行了比较。结果表明，双效循环在冷却水温度低于30℃且蒸发温度高于-15℃的条件下有较高的COP值，但其所需热源温度比其他两种对照循环的高。

英文摘要：

The double-effect NH3-H2O absorption cycle is a novel efficient and compact coupled cycle that uses the absorption heat of high temperature cycle to provide the heat for the generation process of low temperature cycle. Mathematical simulation models were established to calculate and analyze refrigeration performance indices at varying temperatures of heat source, cooling water and evaporation, as well as differential concentration of solution. A comparison of coefficient of performance （COP） of the new double-effect NH3-H2O absorption cycle was made with those of for the traditional single-effect and doublestage cycles. The results showed that the double-effect NH3-H2O absorption cycle had higher COP value at cooling water temperature lower than 30℃ and evaporation temperature higher than -15℃. However, the temperature of heat source should be higher than that of the other two reference cycles.