冷藏车厢内温度波动特性分析

为了控制冷藏车厢内的温度波动,运用频域分析法对造成冷藏车厢内温度波动的4种温度扰动等因素进行了研究。研究结果表明:在保持车厢体积、当量换热面积、传热系数不变,减小系统交接频率,可对各温度扰动进行衰减;保持αF与ρсν的比值不变,可调整制冷机组运行频率及融霜频率处于系统衰减域,或使得制冷与融霜温度扰动的相角相同,达到对这两种扰动进行衰减的目的;减小车厢内外表面的对流换热系数、减少当量换热面积、减小车辆当量渗风孔面积越小、使车厢外表面颜色变浅、增大车速的变化频率等可达到降低车厢内温度波动的效果。

Analysis on Temperature Fluctuations Characteristics of the Refrigerated Compartments

In order to control temperature fluctuations in the refrigerating compartment,using frequency domain analysis method,the four factor causing temperature fluctuation in refrigerating compartments were studied. The results show that the temperature perturbations be attenuated when the compartments volume,equivalent weight heat transfer area,heat transfer coefficient are unchanged,and the handover frequency of the system was reduced. Besides,by adjusting operating frequency and defrost frequency of refrigeration units within system attenuation domain range,or refrigeration temperature perturbation and defrost temperature perturbation is same phase angle,two kinds of temperature perturbation will be attenuated,when keepingαF with ρсν constant ratio. Temperature fluctuations within compartments are reduced when convective heat transfer coefficient of inner and outer surfaces of compartments are reduced,lowering equivalent heat transfer area of compartment,the compartment is equipped with better airtightness,lighter color outer surface,and the vehicle change its speed with a frequent variation.