【作者】 柳飞；

【导师】 何国庚；

【作者基本信息】 华中科技大学 ， 制冷与低温工程， 2005， 硕士

【摘要】 冰浆是一种良好的蓄冷介质,具有很好的流动性和载冷特性。基于区域供冷与大温差送风的设想,采用冰浆作为载冷剂,相对传统的冰蓄冷而言更具有优势。目前,冰浆系统的应用亟待解决的问题包括:冰浆发生器的设计,冰浆流动阻力与换热特性的研究,冰浆储运特性以及冰浆空调系统的开发研究等。本文从冰浆流体的特性出发,说明了目前动态冰晶制取的主要方式,着重分析了采用过冷水或溶液制取冰晶的原理,并对过冷水的形成过程以及过冷器防冻结策略,进行了一定的分析和探讨。文中也给出了冰晶在过冷水中生长的数学模型,并模拟了冰晶在不同过冷度和湍流耗散率下的生长情况。在理论分析的基础上,本文提供了一种动态冰晶制取的方案,实验装置包括制冷系统和过冷水循环系统。水或溶液在过冷器中获得尽可能大的过冷度,过冷消除后,在蓄冰槽中形成冰晶,该方法能够达到动态制取冰晶的目的。本文在制冷量给定的前提下,完成了制冷系统各部分的设计计算,给出了动态冰晶制取的实验装置。在自行搭建的实验台上,采用自来水、纯净水以及乙二醇溶液作为介质,实验给出了相同流速下,不同介质过冷器出口的最大过冷度与冷却速率的关系; 对同一种介质,分析了流动速度对过冷度的影响。针对蓄冰槽中冰晶生成的情况,本文最后分析了影响整个系统稳定运行的相关因素,并对实验系统进行了改进与完善。更多还原

【Abstract】 Ice slurry is an effective coolant with excellent characteristics. Compared with conventional ice storage systems, ice slurry system has many advantages, so we can deal with ice slurry in district heating and cooling systems. Nowadays, many problems that need to be solved eagerly in ice slurry system application include: the design of ice slurry generator, the research of flow and heat transfer characteristics, the research of storage and transportation, the development of ice slurry air-conditioning system, etc. Considering the excellent characteristics of ice slurry, this paper demonstrates the main types of dynamic ice-making system at present, analyzes the principles of using supercooled water or solution to make ice slurry, and discusses the forming process of supercooled water as well as the anti-freezing strategies of supercooler. Under different supercooling degrees and turbulent dissipation rates, the paper poses the mathematical model and makes numerical simulation about the growth of ice crystal in supercooled water. Based on the theoretical analysis, the paper offers the dynamic ice-making system that includes a common refrigeration system and a supercooled water recycle system. Tap water or solution obtains as heavy as possible supercooling degree in supercooler. After subcooling is released, ice crystal comes into being as water falls into the storage tank. Therefore, ice slurry accumulates as the process continues. When the refrigerant capacity is stated, the paper finishes the design of each component of ice slurry system and offers an ice slurry generator by supercooled water. Tap water,pure water, glycol aqueous solution of 6 mass% were adopted as the testing solutions. The paper poses the relations between maximal supercooling degree and cooling velocity at the outlet of supercooler under different coolants. Meanwhile, the paper analyzes the effects that flow velocity has on supercooling degree under the same coolant. According to our experiments, the paper analyzes the factors that affect the stable operating of the system and takes some measures to improve it.更多还原