中文摘要：

地热能是重要的可再生能源,位于地下深处的分布形式符合重力驱动CO2跨临界动力循环应用特点,并且可以耦合CO2地下封存。以地热能为热源,对重力驱动CO2跨临界动力循环开展研究。研究结果表明,循环系统位差随循环加热压力的升高而升高;循环热效率和净输出功率与循环加热压力成正相关关系;由于单位质量CO2吸热能力的降低,工质质量流量随循环加热压力的升高而升高;冷却水质量流量和工质质量流量变化规律相似;当加热压力为16 MPa,热源温度为400℃时,循环热效率为12.27%,净输出功率为178.46 kW。

英文摘要：

Geothermal energy is an important renewable energy. The heat energy is deep in the ground, which is suitable for the gravity driven CO2 transcritical power cycle. Meanwhile, CO2 storage underground can be coupled during the operation of the cycle. Cycle performance is studied for the gravity driven CO2 transcritical power cycle using geothermal energy. The results show that the system position difference increases with increasing the heating pressure. Cycle thermal efficiency and net power output give a positive correlation with the heating pressure. More CO2 is needed with increasing the heating pressure, which is caused by decrease of the specific CO2 heat absorption capacity. The variation of the cooling water mass flow rate is similar with that of the CO2 mass flow rate. When the heating pressure is 16 MPa and the heat source temperature is400℃, the cycle thermal efficiency can reach 12.27% and the net power output of 178.46 kW is achieved.