甘孜地热发电能量分析与?分析

Energy and Exergy Analysis of Geothermal Generation from Ganzi

本文对四川甘孜的一口地热井进行能量分析和?分析,参考该井地热水的温度115℃,采取的发电方式有单级闪蒸系统、预热有机朗肯系统、闪蒸有机朗肯联合系统。结果表明,闪蒸朗肯系统的?效率最高(47.81%),预热朗肯系统次之(46.31%),单级闪蒸系统最低(42.83%)。对于有机朗肯循环,发生器的影响因子及?损均为最大;而闪蒸部分,闪蒸罐的影响因子最高,但闪蒸朗肯系统将其?损减少64.8%,低于汽轮机。计算结果显示,提高闪蒸/发生温度能够提高效率、减少?损,而闪蒸朗肯系统中发生温度有较好的优化性能。综上所述,闪蒸有机朗肯联合系统具有最大的净功率(360.8 k W)和最高的?效率,而且尾水温度最低,热效率适中,适合用于中低温地热发电。

This paper presents the energy and exergy evaluation of a geothermal well from Ganzi, Sichuan. Accordingto the temperature of geothermal fluid, 115℃, we adopt the power generation system with Single-stage Flashing,Preheated ORC and Flashing ORC. The results demonstrate that the Flashing ORC owns the highest exergy efficiencyof （47.81%）, followed by Preheated ORC （46.31%）, Single-stage flashing owns the lowest （42.83%）. For ORC,influence coefficient and exergy loss of generator are the maximum; for flashing, flash drum has the biggest influencecoefficient, but Flashing ORC make the exergy loss reduce 64.8% which is lower than the turbine’s. The results confirmthat higher evaporation temperature can increase exergy efficiency and decrease exergy loss, and evaporationtemperature of generator has better optimization for Flashing ORC. Flashing ORC system that owns the highest network（360.8 kW） and exergy efficiencies, the lowest tail temperature and medium thermal efficiency, is suitable forlow-temperature geothermal power generation.