引入了单、双级压缩制冷系统的单位压缩机理论输气量制冷量的概念 ,并对- 1 5℃蒸发温度氨制冷系统的单、双级实际循环进行了制冷能力和制冷系数两方面的对比分析 ;导出了因采用双级循环而需追加的一次性装置投资的投资动态还本期计算公式 ,并结合一制冰厂实例 ,进行了较为详细的技术经济分析。 The concept of unit capacity of compressor in single-stage and two-stage compression refrigeration system was introduced, and the single-stage and two-stage actual circulation of ammonia refrigeration system with -15 ℃ evaporation temperature were carried out in terms of refrigeration capacity and refrigeration coefficient The comparative analysis is given. The formulas for calculating the dynamic future investment return of the one-time unit investment that need to be added due to the two-stage cycle are deduced, and a detailed technical and economic analysis is carried out based on an example of an ice making plant.