本文提出了一种新型的以冷制冷的氨水吸收式制冷系统。系统利用LNG(液化天然气)气化释放的冷能作为冷源，通过少量的高品位冷能的利用来制取多量的低品位冷能，制冷循环采用氨水吸收式制冷系统。通过对系统的热力分析，结果表明：当制冷温度（蒸发器蒸发温度）为0℃，蒸馏率为0.185，LNG冷能输入系统的温度为-60℃时，系统的性能系数为1.74。在此条件下对系统进行㶲分析，发现吸收器的㶲损失最大，其㶲损系数约为24%，系统总的㶲效率为41%。对系统进行特性规律分析，发现当蒸发器的蒸发温度不变时，发生器氨气蒸馏率的增加会使得发生器操作压力下降，LNG冷却温度下降，但同时系统的性能系数会增加。蒸馏温度越高，系统的性能越好，当制冷温度为10℃时，系统的性能系数可以达到1.8以上。

In this paper, a new model of ammonia-water absorption refrigeration system is proposed and analyzed. Cold energy which is released from the LNG(Liquefied Natural Gas) vaporization will be used in the system as a low-temperature receiver, under the conditions, a small amounts of high-grade cold energy is absorbed by the system and amounts of low-grade cold energy is produced. After having a thermodynamic analysis of the system, the results show that: when the refrigeration temperature(the distillation temperatureof evaporator) is 0℃,the distillation ratio reaches 0.185 and the temperature which LNG input into the system was -60℃, the coefficient of performance of the system is 1.74. Under this condition, the system is analyzed by exergy method, the result shows that the exergy loss of abstraction which coefficient of exergy loss of 27% is the largest among several equipments, and the exergy efficient of the system is 41%. With the increasing amount of distilled ammonia from the top of distillation column, the operating pressure of the distillation column will diminish, the vaporization temperature of LNG will decrease and the quantity of heat absorbed by system will decrease. However, at the same time, the coefficient of performance of the system will rise. Good performance can be gained when the evaporating temperature gets higher. The coefficient of performance of the system can reach above 1.8, as if the refrigeration temperature is 10℃. In addition, exergy analysis of the system has been studied in this paper.

TK264.1

国家自然科学基金重点项目（51436006）