黄金梨差压通风预冷数值分析与实验验证  

Numeral analysis and experimental verification of pressure pre-cooling of golden pears

作　　者：王强[1] 陈焕新[1] 董德发[2] 刘凤珍[2] 

机构地区：[1]华中科技大学能源与动力工程学院,武汉430074 [2]山东建筑大学热能工程学院,济南250101

出　　处：《农业工程学报》2008年第8期262-266,共5页Transactions of the Chinese Society of Agricultural Engineering

基　　金：中国博士后科学基金资助项目(20060400844);华中科技大学博士后科学基金资助项目(2005033)

摘　　要：为给果蔬差压通风预冷送风速度选择、包装箱设计等提供理论参考,根据差压通风预冷流动传热机理,建立了黄金梨预冷仿真模型,利用计算流体动力学(Computational Fluid Dynamics)软件,对包装箱内直排和叉排两种摆放形式黄金梨预冷过程进行了模拟。分析了不同送风速度、开孔形式和开孔大小等参数对黄金梨预冷过程的影响。数值模拟结果和实验测试结果对比分析表明,数学模型较好地反映了差压通风预冷过程中各参数对预冷效果的影响,实验测试验证了理论模型的可靠性。送风速度由1m/s提高到2m/s,黄金梨冷却到5℃时,冷却时间减少了15%～20%;开孔形式对冷却时间的影响在5%左右;40mm和45mm两种开孔大小工况下黄金梨冷却时间差别在10%左右;两种排列摆放方式对黄金梨冷却时间的影响在10%～12%。建议送风速度1.5～2.0m/s,圆形开孔,孔径45mm左右,排列摆放方式为叉排。In order to provide theoretical reference for air flow rate choice and carton design in pressure pre-cooling of vegetables and fruits, a mathematical model of pressure pre-cooling of golden pears was developed according to the flow and heat transfer principles in pressure pre-cooling process. The commercial computational fluid dynamics software was utilized to simulate the cooling process of golden pears with straight and staggered stacking patterns in cartons respectively. The key parameters that affected cooling process such as different air flow rates, type and size of vent hole, were analyzed by simulation and test. Results show that the numerical simulations give the good prediction with the experimental data and mathematical model is reasonable. Cooling time decreases by 15%-20% when air flow rate increases from 1m/s to 2 m/s. The effect on cooling rate of different vent hole types is about 5%. The cooling time of golden pears with vent hole size 45 mm is about 10% shorter than that with vent hole size 40 mm. The effect on cooling time of different stacking patterns is within 10%-12%. Therefore, it is suggested that air flow rate is between 1.5 m/s and 2 m/s, vent hole type is circle with diameter about 45mm, stacking pattern is staggered stacking.

关 键 词：差压预冷 数值模拟 冷却速度 黄金梨 

分 类 号：TB69[一般工业技术—制冷工程]