CO_2跨临界制冷循环中应用两相螺杆膨胀机的理论分析

A THEORETICAL ANALYSIS OF THE APPLICATION OF THE TWO-PHASE FLOW SCREW EXMNDER IN CO_2 TRANSCRITICAL REFRIGERATION CYCLE

本文在介绍利用环保、安全的ＣＯ２作为制冷剂的跨临界循环的基础上，分析了系统各部件的■损失情况，并通过与常规工质对比，提出了采用汽液两相螺杆膨胀机取代系统中节流阀的方法。该方法可明显提高系统的ＣＯＰ，具有广阔的实际应用前景。文章结合ＣＯ２超临界流体的实际特点，对研制、开发ＣＯ２两相螺杆膨胀机提出了设计思想和建议。

Based on a brief introduction to CO2, a safe and environment- protecting refrigerant, used in transcritical refrigeration cycle, this paper presents an analysis of exergy losses of each component of the system. After a contrastive study with the conventional working fluids, the authors propose a method of making use of the two-phase flow screw expander to replace the throttling valve. This method can conspicuously improve the COP of the system, thus having great potentials in practical uses. The authors, taking into account the characteristics of CO2 supercritical fluid, advance suggestion to the design and development of CO2 screw expander.