结构参数对单螺杆膨胀机性能影响的初步实验研究

Preliminary Experimental Study on the Performance of Single Screw Expanders by Structure Parameters

摘要: 目前，中小规模有机朗肯循环系统的实用化仍存在许多问题，其中膨胀机性能是阻碍其应用的重要技术瓶颈，对于确定类型的膨胀机，结构参数对其性能影响较大。影响单螺杆膨胀机性能的结构参数主要是内容积比和配合间隙。本文开展了内容积比及间隙对单螺杆膨胀机性能影响的初步研究工作。结果表明：在相同间隙下，大内容积比的膨胀机效率仅为小内容比的50%左右，容积效率比小内容比的膨胀机低20%。对于小内容积比的样机，大配合间隙与小配合间隙相比，除容积效率略有下降外，功率和膨胀机效率基本没有差异；对于大内容积比的样机，大配合间隙与小配合相比，除容积效率略有下降外，功率和膨胀机效率均有一定幅度增加。

Abstract: Currently, the practical application of medium and small-scale Organic Rankine Cycle system still has many problems. And the performance of expander is an important technical bottleneck which limits its application. For a given type of expander, structural parameters have great influence on its performance. Internal volume ratio and gap are two main structure parameters which impact performance of single screw expanders. This paper carried out a preliminary study on the performance of single screw expanders under the influence of internal volume ratio and gap. The results show that the efficiency of the expander with large internal volume ratio is only about 50% of the one with small internal volume ratio, the volumetric efficiency of the former is lower than that of the latter by 20%. For the prototype of small internal volume ratio, there is no significant difference of power and efficiency of the expander with large fit gap compared with small fit gap, except the volumetric efficiency has a slight downward. For the prototype of large internal volume ratio, power and efficiency of the expander with large fit gap increase a certain extent, but the volumetric efficiency decreases compared with small fit gap.