In this paper, a geothermal energy extraction system has been designed based on a two-phase closed thermosiphon, cascade phase change material heat exchanger, and an organic Rankin cycle. The proposed system is thermodynamically analyzed for supplying power and heat to a selected hotel in Sarein city in Iran. In the first step, the optimum diameter of the two-phase closed thermosiphon, according to the average yearly energy consumption rate ($3100kW$), is obtained. A two-level cascade heat exchanger with a storage medium of phase change materials is used to supply the building's energy consumptions. For the summertime, only the first level of the heat exchanger is operating to drive the ORC unit with two turbines for power generation. The second turbine output power is transmitted to the upper grid. On the other hand, in the wintertime, since the heating demands dominated, besides the first level of the heat exchanger, the second level of the heat exchanger is operated to supply the heating demand. Based on the thermodynamic analysis, employing phase change materials in the heat exchanger is an effective method for reducing overall exergy destruction, and consequently, increasing system efficiency. The energy and exergy efficiency is more favorable in terms of the application of PCM in the heat exchanger.

本文设计了一种基于两相闭式热虹吸，级联相变材料换热器和有机朗肯循环的地热能提取系统。对所提议的系统进行了热力学分析，以为伊朗萨里因市的一家选定酒店提供电力和热量。第一步，根据年平均能量消耗率（$3100ķ\mathrm{w\; ^}$）。具有相变材料存储介质的二级多级换热器用于提供建筑物的能耗。在夏季，只有热交换器的第一级在运行，以驱动带有两台涡轮机的ORC单元发电。第二涡轮机输出功率被传输到上部电网。另一方面，在冬季，由于供热需求占主导，所以除了热交换器的第一级之外，还运行热交换器的第二级来供应供热需求。基于热力学分析，在换热器中采用相变材料是减少总能干破坏的有效方法，从而提高了系统效率。