Abstract:

To study the variation of performance of air conditioning system in the condition of variable chilled water temperature, a performance prediction model for air conditioning system including chiller and cooling coil which based on the modeling method making unknown parameter lumped and getting model parameters from measured data is developed. An experimental device is built up to validate this performance prediction mode, and simulation on performance of air conditioning system under variable chilled water temperature condition is studied. The results show that the relative errors of performance parameters such as cooling capacity and COP (coefficient of performance) between simulation and experiment are within 10%. The increase of COP caused by chilled water temperature increasing from 7℃ to 15℃ is 21.1% when return-air dry-bulb temperature of cooling coil is 28℃, and the dehydration quantity decrease 96.4%. It can be concluded that return-air dry-bulb temperature influences the energy saving effect and dehydration quantity of air conditioning system with variable chilled water temperature, the influence of chilled water temperature on performance of air conditioning system and comfort of indoorenvironment should be considered, and the variation range should be controlled based on setting indoor temperature and supply-air state.

Key words: chiller, cooling coil, variable water temperature, lumped parameters, performance prediction

摘要：

为研究变冷冻水温工况下空调系统整体性能变化规律,基于将未知结构参数集总并由少量实测数据获取模型参数的建模方法,建立了包含冷水机组与空调箱的空调系统变冷冻水温性能预测模型。构建出空调系统变冷冻水温实验装置,并进行系统模型实验验证,在此基础上对不同回风干球温度下空调系统变冷冻水温性能进行了模拟研究。结果表明,制冷量、COP等系统性能参数模拟与实验值偏差在10%以内;在回风干球温度为28℃时,冷冻水供水温度从7℃升至15℃,机组COP提升比例为21.1%,系统除湿量下降96.4%,表明回风干球温度与冷冻水温会同时影响系统运行效率与除湿能力,应综合考虑冷冻水供水温度对空调系统性能与室内舒适性的影响,根据室内设定温度及送风状态要求控制冷冻水供水温度变化范围,为空调系统变冷冻水温节能运行提供指导。

关键词: 冷水机组, 空调箱, 变水温, 参数集总, 性能预测