【作者】 周丽；

【导师】 陈焕新；

【作者基本信息】 华中科技大学 ， 制冷及低温工程， 2007， 硕士

【摘要】 冷板冷藏车作为新型货运车辆,近年来发展迅猛,并不断受到人们的关注。但是,由于受到外界热环境的影响,使得冷板冷藏车货物温度不断升高且分布不均,影响了货物的质量,因此,掌握其运输过程中货物的温度场,使之保持温度合理、分布均匀的环境,是改善货物质量的关键。本文采用数值模拟方法,计算了番茄在冷板冷藏车运输过程中货物区的动态温度场,建立番茄在冷板冷藏车内及货物的新的数学模型,并分析采用货物区中间留出不同间隙的堆码方式以及考虑外界环境温度变化、调温隔板对货物区温度场的影响。研究结果表明:采用多孔介质模型,对有较规则几何形状的果蔬货物进行温度场数值计算,为此类货物的研究提供了一种新的方法;对有较规则几何形状的果蔬货物,堆码方式将影响果蔬类货物的运输质量;当冷却番茄紧密堆码时,由于番茄的导热系数小,内部呼吸热不能及时带走,造成内部温度高,温度分布很不均匀;为了保证冷板冷藏车运输冷却货物的质量,同时考虑冷板冷藏车货物运载量的要求,建议带有呼吸热的货物堆码时中间留一定间隙装载;在运输番茄类没有经过预冷而直接放入冷藏车上的番茄,可以考虑先将调温隔板全开,当货物处于一最佳的冷藏环境内,再关闭调温隔板;在进行列车方面的模拟计算时,环境温度采用动态温度作为边界条件,使模拟结果更能符合实际情况。更多还原

【Abstract】 Hold - over plate refrigerated vehicle is a new - type vehicle , which is rapidly expanding in recent years , and much attention has been continuously paid by people. But due to the thermal environment outside , the cargo temperature of in hold - over plate refrigerated vehicles has a steady increase and uneven distribution , which has a bad effect on the quality of refrigerated cargoes. Therefore, mastering the temperature field of cargoes during transporting period and ensuring reasonable and uniform distribution of the environment is the key to improve the quality of transported cargoes.A dynamic temperature field of tomatoes during transporting period was calculated based on the numerical simulation approach. a mathematical model has been established for tomatoes in hold-over plate refrigerated vehicles and cargoes,and analyzed the different middle of stacking space and considerd the influence of the changes of environment temperature and Diaphragm - regulated temperature.The results show that: Using porous media model which calculate the value of the temperature field of more regular geometric shape of fruits and vegetables cargoes provide a new method for the study of such goods; the quality of transport was affected by Stacking way of the more regular geometric shape of fruits and vegetables cargoes ; When cooling tomatoes was accumulated closely, the high internal temperature and the asymmetrical temperature distribution resulted from the small thermal conductivity of tomatoes which made the internal breath can not be dispelled away immediately ;it is suggested that the clearance should be remained in the cumulating of the goods for the ensurence of the quality and satisfaction of the requirements in the refrigerated transportation of the cargoes; if the tomatoes directly put into the refrigeration car without pre-cooling , the clapboard would be closed when the cargoes were at the optimal temperature in the refrigerator; the results accorded to the actual situation with the temperature of environmental in dynamic boundary conditions in accounting of simulation of the trains.更多还原