A novel combined power and cooling system based on the organic Rankine cycle and the ejector refrigeration cycle for highly efficient utilization of low-grade heat is presented, in which the endothermic process adopts a dual-pressure evaporation approach and the two vapor generators are connected in series. A mathematical model is developed to evaluate the system thermodynamic and exergoeconomic characteristics. The effects of key parameters on system performance are evaluated. Results show that a higher low-pressure evaporation temperature and a higher vapor fraction at the low-pressure vapor generator are conducive to increasing the system cooling output. An optimal high-pressure evaporation temperature exists that gives the maximum exergy efficiency and the minimum sum unit cost of product. Compared with the net power output of the system, the cooling output is more sensitive to the variation of condensation temperature. Among the system components, the ejector has the highest exergy destruction rate and the lowest exergy efficiency. Furthermore, optimization of the system’s performance and working fluid selection for fixed cooling outputs was conducted. The results show that reducing the exergy destruction in the endothermic process is the key to improving system performance, while perfluoropropane was found to be the most suitable working fluid for the proposed system. In the cooling output range of 300–700 kW, a minimum sum unit cost of product of 45.79–58.87 $/MWh can be achieved, and corresponding ranges of net power output, energy efficiency and exergy efficiency are 614.93–430.58 kW, 14.32–19.25%, and 32.3–22.62%, respectively. Finally, the performance of the proposed system is compared with two typical systems for a cooling output range of 300–700 kW. The results show that the sum unit cost of product is reduced by 7.9–11.1%, and the net power output increased by 23.6–40.6% compared with the system with parallel vapor generators. Compared to the system with the ejector installed after the turbine, the sum unit cost of product is increased by 9.16–13.28%, and the net power output is increased by 129.73–118.38%.

提出了一种基于有机朗肯循环和喷射器制冷循环的新型动力与冷却组合系统，可高效利用低品位热量，其中吸热过程采用双压力蒸发方式，两个蒸汽发生器相连。系列。建立了数学模型来评估系统的热力学和能效特性。评估关键参数对系统性能的影响。结果表明，低压蒸气发生器的较高的低压蒸发温度和较高的蒸气分数有利于增加系统的冷却输出。存在最佳的高压蒸发温度，该温度可提供最大的火用效率和最小的产品总和成本。与系统的净功率输出相比，冷却输出对冷凝温度的变化更加敏感。在系统组件中，喷射器的最高能级破坏率和最低能级效率。此外，针对固定的冷却输出，对系统性能和工作流体选择进行了优化。结果表明，减少吸热过程中的火用破坏是提高系统性能的关键，而全氟丙烷是最适合拟议系统的工作流体。在300-700 kW的制冷输出范围内，产品的最低总单位成本为45.79-58.87 $ / MWh，相应的净功率输出，能源效率和火用效率范围为614.93-430.58 kW，14.32-。分别为19.25％和32.3-22.62％。最后，将该系统的性能与两个典型的300-700 kW冷却输出系统进行比较。结果表明，与并联蒸汽发生器系统相比，产品的总单位成本降低了7.9–11.1％，净输出功率提高了23.6–40.6％。与在涡轮机后安装喷射器的系统相比，产品的总单位成本增加了9.16-13.28％，净输出功率增加了129.73-118.38％。