Allam循环-跨临界CO_(2)循环冷电联产系统的热力学分析

A Thermodynamic Analysis for Combined Cooling and Power Systems Consisting of Allam Cycle and Transcritical Carbon Dioxide Cycle

为了实现碳中和目标和液化天然气冷能的充分利用,提出了一种由Allam循环-跨临界CO_(2)循环所组成的冷电联产系统。对联产系统中所涉及的热力设备进行了详细建模,并对系统进行了热力学分析和参数敏感性分析。仿真结果表明,在设计工况下,冷电联产系统的净输出功率比单独的Allam循环提高了9.54%,而且可以输出5.15 MW制冷量。参数分析的结果表明,联合循环的净输出功率随顶循环透平入口温度和透平出口压力的增高先增大后减小,即存在最佳的顶循环透平入口温度和透平出口压力使得联合循环净输出功率最大;当底循环透平出口压力增高时,系统的输出功率和制冷量都明显减小。本文所提出的联产系统具有模块化设计的特点,可以灵活调节容量参数以适应不同的设计条件,且可以实现碳捕集,具有良好的工程前景。

A combined cooling and power system composed of the Allam cycle and transcritical carbon dioxide cycle is proposed to achieve the goal of carbon neutrality and full use of the cold energy of liquefied natural gas.The components in the proposed system are modeled in detail,and the thermodynamic analysis as well as parameter sensitivity analysis of the system is conducted.Simulation results show that the net output power of the cogeneration system is 9.54%higher than that of the single Allam cycle and the cooling capacity of the system is 5.15 MW under the design condition.The results of parametric analysis show that the net output power of the combined cycle increases first then decreases with the increase of the inlet temperature and outlet pressure of the top-cycle turbine,that is,there are optimal inlet temperature and outlet pressure of the top-cycle turbine to maximize the net power output of the combined cycle.When the outlet pressure of the bottom cycle turbine increases,the output power and refrigeration capacity of the system decrease significantly.The proposed cogeneration system has the characteristics of modular design.Thus,this system can flexibly adjust the capacity parameters to adapt to different design conditions,and has a good engineering prospect.