摘要
直接接触式冰蓄冷系统是一种具有广泛应用前景的新型蓄冷系统,在其设计过程中,制冷剂的选择十分重要。从制冷剂与作为蓄冷介质的水之间是否发生水合反应、制冷剂对全球环境问题—臭氧层耗损和温室效应的影响,以及制冷剂在大型空调系统广泛采用的离心式制冷中的循环性能三个方面着手,对目前常用的HCFC-123、HFC-134a等替代制冷剂进行了对比分析,结果表明选用HCFC-123作为直接接触式冰蓄冷系统的制冷剂可满足经济和环保的要求,具有较大的应用前景。
In the direct-contact ice thermal-storage system, refrigerant is injected into water, so that heat transfer takes place directly between two substances in the evaporator. The negligible heat transfer resistance and temperature difference between the refrigerant and water result in a significantly increased heat transfer efficiency and lower manufacturing costs of the system. The direct-contact ice thermal-storage system is therefore more attractive than the conventional ones. The crux in designing the system is to select an appropriate refrigerant. In this paper, a comparative analysis was carried on the following problems of alternative refrigerants, e.g. HCFC-123 and HFC-134a: 1. gas hydrate reactions between refrigerants and water; 2. impacts of refrigerants on ozone depletion and greenhouse effect; 3. theoretical efficiencies of refrigerants and their practical applications in centrifugal chillers. The analysis showed that HCFC-123 absorbs heat and evaporates after it has been injected into water. Slush ice is formed instead of any gas hydrate due to the relatively larger molecular size of HCFC-123. As an environment-friendly refrigerant with negligible effect on ozone depletion, short atmospheric lifetime and low total equivalent warming impact (TEWI), HCFC-123 has high theoretical and practical efficiencies and has found wide application in centrifugal chillers. HCFC-123 is also considered as an excellent refrigerant applied in the direct-contact ice storage system.
出处
《能源研究与信息》
2001年第3期125-132,共8页
Energy Research and Information
基金
国家自然科学基金项目(59876024)
中国博士后科学基金项目
上海博士后科学基金项目
