有机工质向心透平全工况性能分析及工况边界探索  

Overall performance analysis and boundary exploration of organic working medium radial turbine

作　　者：田华[1] 张鹍 王轩[1] 黄广岱 TIAN Hua;ZHANG Kun;WANG Xuan;HUANG Guangdai(State Key Laboratory of Engines of Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《热力发电》2022年第4期38-46,共9页Thermal Power Generation

基　　金：国家自然科学基金优秀青年科学基金项目(52022066)。

摘　　要：向心透平膨胀机具有效率高、结构简单等优点,是有机朗肯循环系统的核心部件,其性能直接影响系统热功转化效率。在内燃机余热回收系统中,透平工作状态会受内燃机复杂多变的工况影响,分析其全工况性能、探索其工况边界特点十分必要。利用计算流体力学软件进行数值模拟,开展向心透平全工况性能分析。结果表明:设计工况下输出功率和效率分别为13.435 kW、79.31%;对于非设计工况,温度变化对透平性能的影响幅度较小;入口压力通过改变透平质量流量来影响输出功率,二者呈线性关系;当入口压力为50%设计值时,透平效率受转速影响变化剧烈,很难再稳定工作;转速对透平工作状态影响较大,在±40%内变化时效率在60%以上,峰值接近80%;当转速变化超过±50%时,效率大幅下降甚至迫近零点,此时透平不宜再运行。该研究结果可为内燃机余热回收系统向心透平设计及实际运行提供参考。Radial turbine is the core component of organic Rankine cycle(ORC)system with high efficiency and simple structure,its performance directly affects the heat-to-power conversion efficiency of the system.In the waste heat recovery(WHR)system of internal-combustion engine(ICE),the working state of turbine is affected by the complex and changeable working conditions of the ICE,so it’s necessary to analyze the overall performance of turbine and explore the characteristics of working conditions boundary.However,the previous work has focused on the performance research near the design conditions.The computational hydrodynamic software is used to carry out numerical simulation and performance analysis for centripetal turbine under full load condition.The result shows that,the output power and efficiency under design condition are 13.435 kW and 79.31%.For off-design conditions,the temperature variation has a small effect on turbine performance.The inlet pressure affects the output power by changing mass flow rate,and the relationship is linear,when the inlet pressure is 50% design value,the efficiency changes dramatically under the influence of rotation speed,it’s hard to work steadily.The rotation speed has a great influence on the working state of turbine,when the speed changes in the range of ±40%,the efficiency is above 60% and the peak value is close to 80%.When the speed changes out of ±50%,the efficiency drops sharply or even approaches 0,at which condition the turbine is not suitable for operation.The results can provide reference for design and operation of ORC radial turbines.

关 键 词：余热回收 向心透平 气动设计 全工况性能 有机工质 

分 类 号：TK14[动力工程及工程热物理—热能工程]