【作者】 李清英；

【导师】 陈杨华；

【作者基本信息】 南昌大学 ， 工程热物理， 2008， 硕士

【摘要】 冰蓄冷空调系统的运行理念是制冷机组在用电低谷时制取冷量,蓄冷系统在用电高峰时释放冷量,从而平衡电力的供求关系。该系统适用于存在用电差价的地区,目的在于节约用户的用电费用,减少高峰用电时的电耗。为优化蓄冷空调系统的结构,进一步达到单位用户既省电又省钱的效果,响应全社会对节能的呼声,本文分析了一个已投入使用的冰球式蓄冷空调系统的运行特性,借助ANSYS有限元分析软件,数值模拟了实际运行参数下的蓄冷空调系统的运行工况,同时通过设定不同的参数,探究了减少蓄冷时间的途径和影响释冷工况的因素。同时利用热力学第二定律,计算出蓄冷系统的各个部件(火用)损失情况。结果表明,蓄冰球的球壁厚度、球体的结构,载冷剂的流入温度与流量都影响着蓄冷系统的热传递速率,且球体几何结构对缩短蓄冷时间的效果最为明显;能量的耗损主要表现在压缩机与冷凝器两大部件上,在减少传热温差的基础上,提高换热器传热性能的途径是减少能耗、提高能效的有效方法。更多还原

【Abstract】 Ice-storage air conditioning systems, which are often applied in regions where electricity is valued with different prices, are based on the refrigeration units producing cold in low demand of electricity, while ice-storage system melting phase-change materials to release cold energy in the peak price load. Thanks to this system, the quantity and the cost can be cut down to some extent. To improve this system and to make better use of energy, an ice-storage air conditioning having been put into operation is analyzed in this paper. One hand, the characters of the system are numerically modeled by software called ANSYS with the principle of finite element method analysis. Some ways to reduce freezing time and factors effecting PCM thaw have been found. The other hand, available-energy costing of every part of the system has been studied basis of second law analysis of thermal systems. It is concluded that the rate of heat transfer is influenced by wall thickness and structure of encapsulated ice storage, and inlet temperature and flux of refrigerant as well, while the structure of encapsulated ice storage taking first place among these factors. The energy loss from compressors and condensers almost take up the whole energy loss of this system. As temperature difference of heat transfer is decreased, performance of heat exchangers should be improved for controlling available-energy cost and increasing the efficient of the system.更多还原