A CO2 boiled off gas (CO2 BOG) reliquefaction system using liquid ammonia cold energy is designed to solve the problems of fuel cold energy waste and the large power consumption of the compressor in the process of CO2 BOG reliquefaction on an ammonia-powered CO2 carrier. Aspen HYSYS is used to simulate the calculation, and it is found that the system has lower power consumption than the existing reliquefaction method. The temperature of the heat exchanger heater-1 heat flow outlet node (node C-4) is optimised, and it is found that, with the increase of the node C-4 temperature, the power consumption of the compressor gradually increases, and the liquefaction fraction of CO2 BOG gradually decreases. Under 85% conditions, when the ambient temperature is 0°C and the temperature of node C-4 is -9°C, the liquid fraction of CO2 BOG reaches the maximum, which is 74.46%, and the power of Compressor-1 is the minimum, which is 40.90 kW. According to this, the optimum temperature of node C-4 under various working conditions is determined. The exergy efficiency model is established, in an 85% ship working condition with the ambient temperature of 40°C, and the exergy efficiency of the system is the maximum, reaching 59.58%. Therefore, the CO2 BOG reliquefaction system proposed in this study could realise effective utilisation of liquid ammonia cold energy.

中文翻译：

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燃料冷能在氨动力CO2运输船CO2沼泽再液化系统中的应用

一氧化碳2蒸发气体（CO2利用液氨冷能的BOG）再液化系统是为了解决CO过程中燃料冷能浪费和压缩机功耗大的问题而设计的2以氨为动力的 CO 上的 BOG 再液化2载体。利用Aspen HYSYS进行模拟计算，发现该系统比现有的再液化方法具有更低的功耗。对换热器heater-1热流出口节点（节点C-4）的温度进行优化，发现随着节点C-4温度的升高，压缩机的功耗逐渐增大， CO液化分数2BOG逐渐减少。85%条件下，环境温度为0℃，节点C-4温度为-9℃时，CO的液态分数2BOG达到最大值，为74.46%，压缩机1的功率最小，为40.90 kW。据此确定了节点C-4在各种工况下的最佳温度。建立了火用效率模型，在环境温度40℃、船舶85%工况下，系统火用效率最大，达到59.58%。因此，CO2本研究提出的BOG再液化系统可以实现液氨冷能的有效利用。