基于气液两相地热源的ORC发电系统工质筛选

Screening of Working Material for ORC Power Generation System Based on Vapor-Liquid Two-phase Geothermal Heat Source

针对以热源温度为140℃的气液两相混合地热流体为热源驱动的有机朗肯循环(ORC)发电系统最佳工质筛选问题,选取6种干工质,通过在MATLAB中搭建系统模型,分析了各工质蒸发温度对系统热力性能的影响,对比了不同蒸气质量分数下最佳蒸发温度随热源温度的变化规律,并研究了热源质量流量对系统净输出功率的影响以及蒸发温度对回灌温度的影响。结果表明:综合考虑工质的热力性能、物理化学稳定性、热源匹配性以及回灌温度对地热ORC发电系统的影响,工质R601a(异戊烷)可作为以140℃气液两相混合地热流体为热源驱动的ORC发电系统的最佳适用工质。

In order to select the optimal working fluid for the organic Rankine cycle(ORC)power generation system driven by a vapor-liquid two-phase hybrid geothermal fluid with the heat source temperature of 140℃,six dry working materials were selected and a system model was built in MATLAB.The influence of each working fluid evaporation temperature on the system thermodynamic performance was analyzed.The variation of the optimal evaporation temperature with the heat source temperature under different steam mass fractions was compared.The influence of heat source mass flow rate on the system net output power and the influence of evaporation temperature on the recharge temperature were studied.Results show that considering the effect of thermodynamic performance,physical and chemical stability,thermal source matching and system recharge temperature on geothermal ORC power generation system,R601a(isopentane)is the best suitable material for ORC power generation system driven by 140℃vapor-liquid two-phase hybrid geothermal fluid as heat source.