直接接触喷射式冰浆制备技术研究

【作者】 刘剑宁；

【导师】 章学来；

【作者基本信息】 上海海事大学 ， 制冷及低温工程， 2007， 硕士

【摘要】 空调蓄冷技术,即是在电力负荷很低的夜间或者低谷电价时段,采用电动制冷机制冷,利用蓄冷介质的显热或潜热特性,用一定方式将冷量贮存起来并在电力负荷较高的白天,也就是用电高峰期,把贮存的冷量释放出来,以满足建筑物空调或生产工艺的需要。对国内外冰蓄冷技术研究热点进行了回顾,提出了直接接触喷射式冰浆制备技术。对直接接触喷射式制冰装置进行了设计。设计过程中解决冷媒与水的分离以及喷嘴、换热器和管道的防冰堵等问题,将制冰罐和换热器制成一体,设计独特的制冰罐及制冰装置结构,并利用预冷、引射等技术,并提高了整个冰浆制备装置的效率和设备的可靠性。提出了直接接触喷射式液滴换热的理论模型,并进行了详细分析,分析中使用了Matlab编程计算。直接接触喷射式制冰及传热理论的提出,为该种方式的设计提供理论依据及参考。论文提出的理论包括:液滴换热面积的计算理论、液滴滞留时间理论、液滴换热理论。理论上解决了制冰罐温度随时间的分布、制冰量与喷射器关系及制冰量、换热量的理论计算方法。根据国内外相关文献,总结出在管道中冰浆流动特性、摩擦阻力、传热关系式,并对冰浆在空调系统中的动态特性、传热性能等进行了分析说明。搭建了直接接触喷射式冰浆制备装置实验台。介绍了试验调试步骤,包括运转前准备、系统的气密性试验、制冷剂的充注、载冷剂的充注、运转检查;对试验过程中遇到的各种问题和解决方法进行了介绍,提出了载冷剂改进方案与蓄冷槽改进方案;对动态冰蓄冷系统进行了深入的实验研究,验证并补充理论研究;实验最终达到了预期的效果,即生成的冰浆流动性好、不发生冰堵、制冰工况稳定。综上所述,本文的工作包括:提出了直接接触喷射式冰浆制备技术;对直接接触喷射式冰浆制备装置进行了设计,并搭建了直接接触喷射式冰浆制备实验台;在此基础上,提出了直接接触喷射式制冰的理论,并对该理论进行了分析及比对计算。该理论的提出为直接接触喷射式制冰方式的设计、制造提供了可靠的依据,同时解决了设计过程中没有成型理论支持的困局。论文的研究具有重要的理论与实际意义。相信随着直接接触式动态冰蓄冷技术不断发展与完善,它将成为二十一世纪空调界的一项主流技术。更多还原

【Abstract】 Ice storage air conditioning is a technology which uses low price electricity in the evening to drive refrigerating systems, and which takes advantage of the characteristics of the change heat storage materials to produce the coolness and storage it. Then it is released when electric price or electric load is high in daytime to supply the needs of air conditioning or productive technology.This paper reviews direct contact ice storage technology at home and abroad, and puts forward to direct jet-type ice making technology based on those idea.Direct jet-type ice storage technology conbines the evaporator with ice making tank together, and jets the refrigerant into the tank directly; heat exchange between water and low temperature refrigerant happened and small ice crystal is created, in this way it can produce ice slurry.Direct jet-type ice making device is designed. It makes heat exchanger and ice making tank as a whole, which an unique structure for ice making tank and ice making device is used, and gets use of pre-cooling and injection technology; in this way productivity and the reliability of the device is advanced.The paper puts forward to direct jet-type droplet heat transfer theoretical model, compared with different situations using Matlab. The model provides theoretical basis and reference for its design and application. The paper puts forward to those theories including droplet heat transfer theory, droplet resident time theory, droplet heat transfer area theory etc. those theories solve temperature distribution adapting to time, the relationship between ice making capability and injection characteristics, calculative method for heat transfer capability etc.The paper also sums up characteristic of ice slurry in the pipe, friction resistance and heat transfer relationship based on reference at home and abroad, and analyses dynamic characteristics and heat transfer function of ice slurry in the air conditioning.Direct jet-type ice slurry device is built. The paper introduces preparing for the research, how to add refrigeration, how to check the device during working; put forward to ice storage tank improving method and refrigeration replace method; after experiment supply theory and experimental research. Finally get the wanted effect, get liquidity ice slurry and ice block does not happen.Although the paper put forward reliability theory for direct jet-type ice making device, the technology has many works to be done in the future.Believe direct Jet-type ice slurry maker technology will become a mainstream at 21 century with development of the technology.更多还原