基于部件模型约束的制冷系统变工况性能分析

Variable operating condition performance analysis of refrigeration systems based on component model constraints

为了探究制冷系统在不同工况的性能,建立了基于部件模型的制冷系统仿真模型。当蒸发温度-6℃到10℃,冷凝温度30℃到50℃之间变化时,通过求解部件模型之间的热力学耦合关系,分析变工况对系统运行状态的影响。此外,研究了变工况对系统部件及整体(火用)损与(火用)效率的影响。结果表明,系统在蒸发温度为0℃以下能稳定运行,冷凝温度从30℃到50℃变化期间,蒸发器出口过热度最大变化达到3.9℃。冷凝温度从35℃调整到45℃时,蒸发器(火用)损失减少14.28%,制冷负荷减小10%,系统总(火用)损失增加4.45%,系统(火用)效率下降最大不超过3%。

A simulation model of refrigeration systems was built by using component models to investigate the performance of refrigeration systems under various operating situations.The thermodynamic coupling relationship between component models was solved to examine the impact of various operating conditions on the system operation status when the evaporation temperature varies from-6℃to 10℃and the condensation temperature varies from 30℃to 50℃.The results show that the system can function reliably at evaporation temperatures below O C,and the highest variation in superheat at the outlet of the evaporator is 3.9℃within the condensation temperature range of 30℃to 50℃.By increasing the condensation temperature from 35℃to 45℃,the evaporator exergy loss drops by 14.28%,the refrigeration load decreases by 10%,the overall exergyloss of the system increases by more than 4.45%,and the highest decline in system exergy efficiency is less than 3%.