Abstract To get more out of geothermal power generation, integration of energy storage technologies to geothermal power plants could be used for base load peak shaving operations. Cryogenic energy storage is one the attractive options to store geothermal power during off-peak hours and produce power during peak hours. In this study, a new configuration consisting of a binary geothermal power plant, an air liquefaction unit, and a cryogenic organic Rankine cycle is considered and analyzed using the first and second laws of thermodynamics. A geothermal resource available at 180 °C with a flow rate of 100 kg/s is used to power a binary cycle power plant with isopentane as the working fluid. Binary power plant produces 6253 kW power, which is used to liquefy air during a 6-h charging operation. During discharge operation, the liquefied air is pumped, and used as a heat sink for the cryogenic organic Rankine cycle with propane as the working fluid. The cryogenic organic Rankine cycle produces 1387 kW power. The liquid air after condensing operation is heated in the heaters with stored heat during charging operations and expanded in turbines for additional power generation. During the discharge operation, 10,660 kW power is produced by the combined cryogenic energy storage and cryogenic organic Rankine cycle unit while the total power generation is 16,920 kW. The cryogenic organic Rankine cycle system has a thermal efficiency of 35.3 % and a second law efficiency of 29.2 %. The storage system has a round-trip efficiency of 28.4 % and a second law efficiency of 59.7 %. Six different working fluids are analyzed and compared for the cryogenic organic Rankine cycle. Effects of condensing temperature and compressor outlet pressure of the cryogenic organic Rankine cycle, and geothermal resource temperature on the system performance are investigated.

中文翻译：

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将低温储能和低温有机循环集成到地热发电厂

摘要 为了充分利用地热发电，将储能技术与地热发电厂相结合，可用于基本负荷调峰作业。低温储能是在非高峰时段储存地热能并在高峰时段发电的有吸引力的选择之一。在这项研究中，使用热力学第一和第二定律考虑和分析由二元地热发电厂、空气液化装置和低温有机朗肯循环组成的新配置。使用 180 °C、流速为 100 kg/s 的地热资源为以异戊烷作为工作流体的双循环发电厂提供动力。二元发电厂产生 6253 千瓦的电力，用于在 6 小时充电操作期间液化空气。在排放操作期间，液化空气被泵送，并用作以丙烷为工作流体的低温有机朗肯循环的散热器。低温有机朗肯循环产生 1387 kW 的功率。冷凝操作后的液态空气在充电操作期间通过储存的热量在加热器中加热，并在涡轮机中膨胀以产生额外的电力。放电运行时，低温储能与低温有机朗肯循环联合机组发电10660千瓦，总发电量为16920千瓦。低温有机朗肯循环系统的热效率为 35.3%，第二定律效率为 29.2%。该存储系统的往返效率为 28.4%，第二定律效率为 59.7%。针对低温有机朗肯循环分析和比较了六种不同的工作流体。