CO_2液化项目中液化压力及制冷剂的选择

The Selection of Liquefaction Pressure and Refrigerant in CO_2 Liquefaction Project

随着CO2减排日益成为世界各国研究的焦点,在CO2液化项目中,实现节能降耗,同时兼顾节省投资、简化系统等,是具有重要的现实意义的。本文对采用制冷机直接液化CO2的方案进行了分析,探求最佳液化压力、分析适合选用的制冷剂,以期最大程度的降低能耗。通过计算,总结了液化总功耗随液化压力的变化规律:随着液化压力的提高,液化总功耗降低,但降低的幅度逐渐减小。在工程项目的实际应用中,应尽量提高液化压力;在采用较低的液化压力时,选用带经济器的制冷机是最佳选择。另外,对于CO2液化过程中采用不同制冷剂时的性能进行了比较,指出应优先选用氨或R507作为制冷剂。

As the research of CO2 emission reduction has become a hot topic around the world, it is ofgreat significance in CO2 liquefaction project to reduce energy consumption and cost, and meanwhile tosimplify the system. In order to reduce the energy consumption to a great extent, this paper analyzed thetechnical proposal using refrigerator to liquefy CO2, and discussed the optimum liquefaction pressure andrefrigerants. Through calculation, it summarized the variation tendency that total power consumption in-fluenced by liquefaction pressure ： with the rising of liquefaction pressure, the total power consumption re-duces, but the reduce amplitudes decreases. In practical projects, the liquefaction pressure should be setas high as possible. In cases that low liquefaction pressure cannot but be used, refrigerator with an econ-omizer can be used as an optimum solution. For CO2 liquefaction process, the refrigeration cycle perform-ances are analyzed and studied with different refrigerants, which indicate that R717 and R507 are opti-mum refrigerants.