为节约及合理利用能源，提高城市能量总能系统利用率，基于有机朗肯循环（ORC）和冷热电联产（CCHP），提出了一种新型的城市低温地热冷热电联产系统(以下简称ORC-CCHP系统)。根据热力学第一、第二定律，建立了热力学模型，编写计算机程序进行了系统的热力性能分析。结果表明：采用R245fa、LiBr溶液作为ORC-CCHP系统循环工质时，选择窄点温差较小蒸发器可获得更高〖HT5”，7〗火〖KG-*3〗用〖HT5”〗效率；增加太阳能集/蓄热系统,提高热流参数，减小换热温差，可进一步提升系统热力学性能；系统分别采用5种不同有机工质时，R236fa使系统的热力性能达到最佳，并在蒸发压力为0.62 MPa、窄点温差为0 K时，ORC-CCHP系统获得最大净输出功为1 948 kW，系统〖HT5”，7〗火〖KG-*3〗用〖HT5”〗效率为19.28%，系统〖HT5”，7〗火〖KG-*3〗用〖HT5”〗效率最高值为85.78%。

In order to save and rationally use energy and improve the utilization rate of urban energy,a new type of urban lowtemperature geothermal CCHP system is proposed based on organic Rankine cycle (ORC) and combined cooling heating and power (CCHP)(hereinafter referred to as ORC-CCHP system).According to the first and second laws of thermodynamics,a thermodynamic model was established and a computer program was developed to analyze the thermodynamic performance of the system.The results show that when R245fa and LiBr solutions are used as the circulating working fluid of ORC-CCHP system,the evaporator with smaller pinch point temperature difference can be selected to obtain higher efficiency.Increasing solar energy collection/regenerative system,improving heat flow parameters,and reducing heat transfer temperature difference can further significantly improve the system thermodynamic performance.When the system uses five different organic working fluids,the R236fa has the best thermodynamic performance of the system,and when the evaporation pressure is 0.62 MPa and pinch point temperature difference is 0 K,the ORCCCHP system has the maximum net output power of 1 948 kW and the system thermal efficiency of 19.28%,with the maximum system exergy efficiency of 85.78%.

TM61

国家自然科学基金(51574136,51574138)