中文摘要：

本文以R123为流动工质，进行离心透平级的一维热力计算，并通过数值模拟分析ORC离心透平级内流动情况及变工况性能。结果表明：在设计工况下，数值模拟结果与一维设计结果基本一致，功率与效率偏差在1％以内，符合设计要求。在变工况下，进汽压力在0．33-O．88MPa变化时，效率随进汽压力增大先增大后减小，流量和功率随进汽压力增大而增大；背压在O．10-0．18MPa变化，在临界工况下运行，效率和功率随着背压的增大而减小，流量保持不变；初温改变对透平性能影响较小，效率变化范围在1％以内；转速变化时，流量不变，效率先增大后减小，设计转速下效率最高。

英文摘要：

In this paper, the one-dimensional design of the centrifugal turbine was conducted by using R123 as working fluid. Combining with CFD technology, the aerodynamic performance analysis of the centrifugal turbine stage was carried out both in design and off-design conditions. The results show： in the design condition, the CFD results mostly agree with the one-dimensional design; relative errors of power and efficiency are within 1%, efficiency and power of the turbine satisfy the design requirements. In the off-design conditions, when the inlet pressure increased from 0.33 MPa to 0.88 MPa, the efficiency increased at first, then decreased; mass flow and power increased with the increasing of the inlet pressure. When the back pressure increased from 0.10 MPa to 0.18 MPa which is smaller than the critical back pressure, efficiency and power decrease with the increasing of the back pressure, mass flow maintains constant. The variation of inlet temperature showed less effect on stage performance, the variation of efficiency is within 1%. When the rotor speed varies, efficiency increases with the increasing of the rotor speed, reaches a maximum value at design speed, and then decreases with any further increase in rotor speed, mass flow maintains constant.