LNG冷能发电工质选择与参数优化

Selection of working fluid and parameters optimization for cryogenic power generation of LNG

关键词:  液化天然气  冷能发电  工质选择  参数优化 

Key words:  liquefied natural gas (LNG)  cryogenic power generation  selection of working fluid  parameter optimization

摘要:

以某公司LNG冷能发电项目为优化对象,采用HYSYS流程模拟软件对循环工质及参数进行模拟计算。模拟结果表明,甲烷、乙烷和丙烷混合工质的最大发电量高于各单质工质,混合工质配比不同,净发电量不同,混合工质配比存在一个最佳值。在混合工质中,增加丙烷含量或甲烷/乙烷比例,发电量均呈现先增加后降低的趋势。运行参数影响发电量,膨胀机入口压力的变化对系统净发电量的影响程度小于膨胀机出口压力,随膨胀机出口压力的增加,发电量呈先增加后降低的趋势,而且同一工质的最大净发电量所对应的膨胀机出口压力相同。 

Abstract:

Taken a company’s LNG (liquefied natural gas) cryogenic power generation project as an optimized object, the selection of working fluid and optimization of parameters were simulated by Aspen HYSYS. The simulation results demonstrated that the mixture of methane, ethane and propane as working fluid has more power generation than single substance, different proportions of the mixture generate different net power, and there is an optimal proportion. In the mixed substance, increasing the proportions of the propane or methane/ethane, electricity production presents a tendency of lower after the first increase. Furthermore, operation parameters have a great influence on the power generation. In comparison with inlet pressure of expander, the outlet pressure has more influence on power generation. While the outlet pressure of expander increases, the power generation first increases and then decreases. Meanwhile, the maximum net power generation for the same working fluid appears under the same outlet pressure condition with the different inlet pressures.