• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2017, Vol. 53 ›› Issue (24): 177-183.doi: 10.3901/JME.2017.24.177

• 运载工程 • 上一篇    下一篇

采用螺杆膨胀机的ORC系统特性试验研究

郭霆, 沈九兵, 孔祥雷, 张震   

  1. 江苏科技大学能源与动力学院 镇江 212003
  • 收稿日期:2017-08-15 修回日期:2017-11-27 发布日期:2017-12-20
  • 通讯作者: 沈九兵(通信作者),男,1987年出生,博士研究生。主要研究方向为螺杆机械及其系统应用。E-mail:jackcoolman@126.com
  • 作者简介:郭霆,男,1975年出生。主要研究方向为建筑和动力设备控制与节能。E-mail:guoting75@163.com
  • 基金资助:
    江苏省青年基金资助项目(BK20150380)。

Experimental Investigation on the Characteristics of ORC System with Twin Screw Expander

GUO Ting, SHEN Jiubing, KONG Xianglei, ZHANG Zhen   

  1. School of Energy and Power, Jiangsu University of Science and Technology, Zhenjiang 212003
  • Received:2017-08-15 Revised:2017-11-27 Published:2017-12-20

摘要: 有机工质朗肯循环(Organic Rankine cycle,ORC)能回收工业余热产生高压蒸气,并由膨胀机输出机械功,是一种具有广泛应用前景的节能技术。工质泵和膨胀机作为ORC循环运行的两大核心机械,实现不同热源流量或温度条件下,工质泵频率和膨胀机转速的匹配,可有效提高ORC循环效率。基于ORC循环的热力学分析,选用R245fa作为循环工质,采用适用性广、可靠性高的螺杆膨胀机,设计并搭建了ORC系统试验台,根据试验结果,重点研究螺杆膨胀机转速、工质泵频率及蒸发器出口过热度对系统性能的影响。结果表明:膨胀机转速的增加会使得系统中工质的循环流量上升,但对蒸发压力的影响较小;存在与工质泵频率相匹配的最佳膨胀机转速,使得系统的循环热效率达到最大;工质泵频率增加时,工质的循环流量和蒸发温度也随之增大,蒸发器换热量、膨胀机输出功率及系统循环热效率都有所上升;蒸发器出口过热度的变化基本不会影响系统热效率。

关键词: 螺杆膨胀机, 特性研究, 有机工质朗肯循环

Abstract: The organic Rankine cycle (ORC) is a promoting energy saving technology which recycles the heat of low temperature and converts it to mechanical power. The expander as a key component has great influence on the system's efficiency. Among different types of expander, twin-screw expanders draw much attention due to its advantages of high reliability, strong adaptability and less parts. An ORC system with twin screw expander is designed and a corresponding test rig is developed choosing R245fa as its working fluid. Then, an experimental study of the ORC system is carried out to analyze the influence of the expander speed, working medium pump frequency and the superheat degree of the vapor into the expander. The results show that the mass flow rate of working fluid increases with the increase of expander rotational speed, but the evaporating pressure is less affected by the expander speed. The system efficiency exists an optimal value when the expander speed matches well with the pump frequency. The mass flow rate of working fluid and the evaporating pressure increase with the increase of working medium pump frequency. As a result, the expander output power and system efficiency will also increase. The superheat degree of working fluid has little effect on the system efficiency.

Key words: characteristics investigation, organic Rankine cycle, twin screw expander

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