Abstract The geothermal energy is a renewable energy resource, which is viewed as a promising alternative to fossil energy. Powered by geothermal energy, the combined cooling heating and power (CCHP) system can potentially become an option for efficient energy supply. However, the operation of the CCHP system is subject to energy demand and temperature degradation of geothermal water. To capture the dynamic characteristics and off-design performance of CCHP system under different working conditions, the dynamic mathematical models of a CCHP system is established and a control strategy is proposed. On this basis, the effect of heating/cooling load on the dynamic behavior of the CCHP system is analyzed and the effect of temperature degradation of geothermal water on the off-design performance is investigated. The results indicate that the lower heating/cooling load leads to greater overshoot and longer settling time in the dynamic process. The settling time of Cooling-Power mode is much longer than that of Heating-Power mode. As the temperature of geothermal water decreases from 120 °C to 108 °C, the heating capacity of the CCHP system decreases by 28.87% and the cooling capacity decreases by 14.72%.In addition, the operation simulation shows that the CCHP system can precisely track hourly heating and cooling load of the student dorm building.

中文翻译：

---

地热驱动冷热电联供系统动态分析与运行仿真

摘要 地热能是一种可再生能源，被视为替代化石能源的一种有前景的能源。由地热能提供动力的冷热电联供 (CCHP) 系统有可能成为高效能源供应的一种选择。然而，CCHP 系统的运行受能源需求和地热水温度下降的影响。为了捕捉冷热电联供系统在不同工况下的动态特性和设计外性能，建立冷热电联供系统的动态数学模型并提出控制策略。在此基础上，分析了冷热负荷对冷热电联供系统动态行为的影响，研究了地热水温度退化对非设计性能的影响。结果表明，较低的加热/冷却负载导致动态过程中更大的超调和更长的稳定时间。Cooling-Power 模式的建立时间比 Heat-Power 模式长得多。随着地热水温度从120℃降低到108℃，CCHP系统的制热能力下降28.87%，制冷能力下降14.72%。 此外，运行仿真表明CCHP系统可以精确跟踪学生宿舍楼的每小时供暖和冷负荷。