马善军, 李鹏辉, 孔令健, 李少华, 韩吉田. 蒸发式过冷水制冰液滴蒸发结晶的模拟[J]. 农业工程学报, 2016, 32(23): 213-217. DOI: 10.11975/j.issn.1002-6819.2016.23.029
    引用本文: 马善军, 李鹏辉, 孔令健, 李少华, 韩吉田. 蒸发式过冷水制冰液滴蒸发结晶的模拟[J]. 农业工程学报, 2016, 32(23): 213-217. DOI: 10.11975/j.issn.1002-6819.2016.23.029
    Ma Shanjun, Li Penghui, Kong Lingjian, Li Shaohua, Han Jitian. Modeling of water droplet in super-cooling water evaporative system for ice slurry production[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2016, 32(23): 213-217. DOI: 10.11975/j.issn.1002-6819.2016.23.029
    Citation: Ma Shanjun, Li Penghui, Kong Lingjian, Li Shaohua, Han Jitian. Modeling of water droplet in super-cooling water evaporative system for ice slurry production[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2016, 32(23): 213-217. DOI: 10.11975/j.issn.1002-6819.2016.23.029

    蒸发式过冷水制冰液滴蒸发结晶的模拟

    Modeling of water droplet in super-cooling water evaporative system for ice slurry production

    • 摘要: 蒸发式过冷水制冰系统中液滴传热传质特性研究具有重要意义。为了分析蒸发式过冷水制冰系统中液滴的热质传输特性,该文将单个液滴冷却结晶过程分为全液相区、固-液两相区和全固相区3个不同区域,建立液滴在大空间内蒸发降温结晶过程的数学模型,通过数值求解方法研究其在大空间蒸发室内降温结晶过程的温度变化特性,进一步分析液滴和空气的入口参数与液滴整个蒸发结晶特性的关系,为蒸发式过冷水制冰系统的结构优化设计和运行管理提供参考依据。

       

      Abstract: Abstract: Ice storage technology is considered as one of the most promising options to achieve the so-called "peak load leveling of power system" and to relieve the contradiction between the supply and demand of peak power currently encountered in China. Among the ice-producing methods being developed around the world, the evaporative supercooling water ice-making one is a new and efficient way for ice slurry production of large scale without ice blockage. Therefore, it is of significant importance to investigate the heat and mass transfer characteristics during the cooling and crystallization process of water droplets in the evaporative supercooling water ice-making chamber to the development of practical ice-making system. In order to analyze the heat and mass transfer characteristics of water droplets in an evaporative super-cooling water system for ice slurry production, we proposed a mathematical model for the cooling and crystallization process of a single water droplet falling in the evaporation chamber with large space, which comprehensively took into account the three different zones of entire liquid phase, solid-liquid interphase and entire solid phase during the cooling and crystallization process of a water droplet. The developed mathematical model was then validated by use of the theoretical and experimental results presented in the available literature and satisfactory agreement was achieved in between the model simulation results and the research ones reported in the literature, indicating the correctness of the mathematical model. The parameter variations of the water droplet with changes in some of the key system operating variables, such as the inlet size and temperature of water droplet, the flow rate and relative humidity of the cold air, were numerically determined by solving the developed mathematical model. Effects of the inlet size and temperature of water droplet, inlet temperature, flow rate and relative humidity of the cold air in the evaporation chamber on the entire cooling and crystallization process were analyzed in detail. The results indicated that the cold air temperature, relative humidity and flow rate had significant effect on the cooling and crystallization process of water droplets. And change in the air temperature had the most obvious impact on the cooling rate of water droplets. Both of the air temperature and relative humidity determined the minimum temperature (i.e., the wet-bulb temperature) that the droplets can reach in the evaporative supercooling water chamber for ice slurry production. Air velocity was one of the key factors influencing the ice crystal production. It can be concluded from the obtained simulation results that decrease in the inlet diameter of water droplets entering the evaporative supercooling chamber was helpful to enhance the speed of evaporative and crystallization process of water droplets. As a result, it was recommended to incorporate water droplets with diameters as small as possible in practical applications. In order to reduce the energy consumption for ice-making, it was important to employ a higher air temperature in meeting the wet-bulb temperature requirement. While increasing the cold air speed can improve the ice slurry output of ice-making system, it may result in increase in the carrying volume of water droplets. Therefore, the cold air speed should be determined according to the corresponding diameters of water droplets entering the supercooling evaporative chamber. The conclusions obtained in this paper were of significance to the efficient structural design and practical operation of the super-cooling water evaporative system for ice slurry production of large scale.

       

    /

    返回文章
    返回