低温热源有机工质向心透平变工况特性分析

Off-design Performance Analysis of Radial Turbine Using Organic Working Fluid for Low Temperature Heat Sources

有机物朗肯循环发电系统广泛应用于工业余热、太阳光热和地热等低温热源回收利用领域。作为关键做功部件,膨胀机的性能对有机物发电系统效率和输出功率有着重要的影响。该文针对温度为150-200℃的工业烟气余热,选择R600a为循环工质,进行了适用于有机物朗肯循环发电系统的150k W级有机工质向心透平初步设计和变工况性能研究。在一维气动热力计算和CFD数值模拟基础上,获得了向心透平设计工况气动性能,研究了入口压力、入口温度以及转速对向心透平变工况性能的影响。结果表明,入口压力对有机工质向心透平性能影响最大,转速次之,入口温度的影响最小。同设计工况相比,入口压力变化约±6.25%（±0.1MPa）时,向心透平功率变化约±7.4%（±12 k W）,效率变化约±1.2%（±1%）,流量变化约±6.58%（±0.27 kg/s）。

For recycling the waste heat from industrial waste gas with a temperature of 150-200℃, R600 a is as the working fluid of the ORC power generation cycle. The preliminary design and performance analysis of the 150 k W-level organic working fluid radial turbine for ORC power generation system was conducted. Based on the one-dimensional aerodynamic and thermodynamic calculation and the CFD numerical simulation, the aerodynamic performance of the organic working fluid radial turbine at design condition was obtained. Then the effects of inlet pressure, inlet temperature and rotation speed on the performance of the organic working fluid radial turbine at off-design condition were analyzed. The results show that the inlet pressure has the largest effect on the performance of the organic working fluid radial turbine, followed by the rotation speed, and then the inlet temperature has the minimum effect. Comparing with the design conditions, a ±6.25% change of inlet pressure（±0.1MPa） can result in approximately a ±7.4% change of output power（±12 k W） of the organic working fluid radial turbine, a ±1.2% change of efficiency（±1%） and a ±6.58% change of flow rate（±0.27 kg/s）.