冷水机组变流量性能预测模型与实验研究

Performance prediction model for chiller with variable water flow and its experiment validation

为实现在冷水机组结构参数缺乏的条件下,对冷水机组变流量工况下的性能进行准确预测,提出了一种将冷水机组未知结构参数集总并基于少量机组实测数据获取模型参数的建模方法,建立了相应的冷水机组变流量性能预测模型.通过搭建冷水机组变流量实验装置并进行实验,获得其模型参数并对机组变流量性能进行了模拟与实验对比.结果表明:该建模方法的模型参数获取简便,模型性能预测精度较高,制冷量、COP等系统性能参数偏差在10%以内,能较好地表征冷水机组变流量工况下的性能变化规律.冷冻水流量从额定流量的100%降至42.8%时,冷水机组制冷量减小8.6%,COP减小8.8%;冷却水流量从额定流量的100%降至24.2%时,冷水机组制冷量减小1.8%,COP减小14.8%,可为空调系统的变流量优化运行提供指导.

To simulate existing chiller with variable water flow accurately under the condition of con-figuration parameter absence,a modeling method which makes unknown parameters lumped and ob-tains model parameters based on measured data of chiller is proposed.A performance prediction model for chiller with variable water flow is developed,and an experimental device is built up to ob-tain the parameters of the model and make a comparison on the performance of chiller between simu-lation and experiment.The results show that by this modeling method,the parameters of the model are easy to gain,and the performance prediction accuracy of the model is high.The relative errors of performance parameters such as cooling capacity and COP （coefficient of performance）between simulation and experiment are within 10%,and the variation of the performance of chiller with varia-ble water flow can be represented accurately.When chilled water flow decreases from 100%to 42.8%of the rated flow rate,cooling capacity decreases 8.6%and COP decreases 8.8%.When cooling wa-ter flow decreases from 100%to 24.2%of the rated flow rate,cooling capacity decreases 1 .8%and COP decreases 14.8%.The results can provide evidence for the optimal operation of chiller.