Abstract

In this work, a thermodynamic analysis consisting of energy and exergy analyses is carried out to determine the performance of a single flash geothermal power plant. A new derivation for determination of the optimum separator temperature, which results in maximum turbine power output, is achieved. The energy and exergy analyses are carried out at that optimum separator temperature. The thermodynamic derivation showed that the separator would result in maximum performance of the power plant when it operates at the average value of the production well and condenser temperatures. Moreover, the derivation was numerically validated by calculating three different values for the geothermal well temperatures. The results show that the highest exergy destruction rate is in the expansion valve followed by the steam turbine, the mixing process and the pump. The separator has exactly zero exergy destruction rate while the condenser has almost zero exergy destruction rate. The results also show that the exergy destruction rate for all components of the power plant decreases with reduction in the geofluid temperature of the production well except for the condenser. The maximum energy efficiency of the power plant is about 12.5, 11 and 9.5% when the geofluid of the geothermal well temperature is 300, 275 and 250°C, respectively.

中文翻译：

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最佳分离器温度下单闪式地热发电厂的能量和火用分析

摘要

在这项工作中，进行了由能量和火用分析组成的热力学分析，以确定单个闪蒸地热发电厂的性能。实现了用于确定最佳分离器温度的新推导，从而实现了最大的涡轮机功率输出。能量和火用分析是在最佳分离器温度下进行的。热力学推导表明，当分离器在生产井和冷凝器温度的平均值下运行时，它会导致发电厂的最大性能。此外，通过计算地热井温度的三个不同值，对推导进行了数值验证。结果表明，最高火用破坏率在膨胀阀中，其次是汽轮机、混合过程和泵。分离器的火用破坏率恰好为零，而冷凝器的火用破坏率几乎为零。结果还表明，除冷凝器外，电厂所有部件的火用破坏率随着生产井地流体温度的降低而降低。当地热井的地液温度为300、275和250℃时，电厂的最大能效分别约为12.5%、11%和9.5%。