Modeling and optimization of a binary geothermal power plant
Modeling and optimization of a binary geothermal power plant
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DOI：
10.1016/j.energy.2012.10.039
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发表时间：
2013-02
期刊：
影响因子：
9
通讯作者：
H. Ghasemi;M. Paci;Alessio Tizzanini;A. Mitsos
中科院分区：
文献类型：
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作者：
H. Ghasemi;M. Paci;Alessio Tizzanini;A. Mitsos
利用低温地热源为现有有机朗肯循环 (ORC) 开发了一个模型。该模型在 Aspen Plus® 中实施，用于模拟配备风冷冷凝系统的现有 ORC 的性能。该模型包括组件的所有实际特性。该模型通过各种环境温度下约 5000 个测量数据进行了验证。系统的净功率输出最大化。结果根据环境温度提出了不同的最佳运行策略。现有文献声称没有过热度对于系统的最大性能来说是最佳的。这仅在低环境温度下得到证实。对于中等环境温度 (Tamb≥ 1.7 °C)，过热可最大化系统的净功率输出。最佳过热度值随着环境温度的升高而增加。优化运行使年总发电量增加9%。此外，还开发了一种更简单的半解析模型，可以非常快速地优化循环的运行。基于冷凝器的夹点条件，推导了一个简单的显式公式，该公式预测涡轮机的出口压力作为工作流体质量流量的函数。
A model is developed for an existing organic Rankine cycle (ORC) utilizing a low temperature geothermal source. The model is implemented in Aspen Plus®and used to simulate the performance of the existing ORC equipped with an air-cooled condensation system. The model includes all the actual characteristics of the components. The model is validated by approximately 5000 measured data in a wide range of ambient temperatures. The net power output of the system is maximized. The results suggest different optimal operation strategies based on the ambient temperature. Existing literature claims that no superheat is optimal for maximum performance of the system; this is confirmed only for low ambient temperatures. For moderate ambient temperatures (Tamb≥ 1.7 °C) superheat maximizes net power output of the system. The value of the optimal superheat increases with increasing ambient temperature. The optimal operation boosts the total power produced in a year by 9%. In addition, a simpler and semi-analytic model is developed that enables very quick optimization of the operation of the cycle. Based on the pinch condition at the condenser, a simple explicit formula is derived that predicts the outlet pressure of the turbine as a function of mass flow rate of working fluid.