冷藏车开门状态升温影响因素分析

Influence Factors of Air-temperature Increasing within Refrigerated Trucks during Door-opening State

基于动态热平衡理论,建立了冷藏车开门状态厢内温度数学模型,并进行相应的试验验证,分析相关参数对车厢内温度的影响。研究结果表明:当制冷机组开启或关闭并打开车门6 min,车厢内初始温度为0℃时,前者比后者升温仅低0.3℃,车厢内初始温度为-15℃时,前者比后者升温仅低0.7℃。当车厢内初始温度为0℃,蒸发器出风口风速分别为4 m/s与2 m/s、或者当隔热材料导热系数分别为0.05 W/(m·K)与0.033 W/(m·K)时,冷藏车开门6 min后前者比后者温度升高均要低约0.2℃。此外,车厢内外的温差越大、车门开启越大、车厢体积越小,车厢内的温度升高也相应的越大;车厢外有、无风,或者风向不同,开门状态车厢内的升温快慢也不同。

The drastic changes of interior air-temperature and humidity induced by intense heat-mass exchange between inside and outside make the quality of perishable food difficult to guarantee while the door of the refrigerated truck is opened in the process of refrigerated transport. Aiming above problems, a mathematical model of interior temperature of refrigerator truck under the open-door state was established based on the theory of dynamic heat balance, and testified correspondingly through the analysis of influence of parameters on temperature. The test results showed that, when the refrigeration system turned on or off, and the door was opened in the 6 min, and the initial temperature of the compartment was 0℃ , the former temperature was 0.3 ℃ lower than the latter temperature. Similarly the former temperature was 0. 7℃ lower than the latter temperature, when the refrigeration system turned on or off, and the door was opened in the 6 min, and the initial temperature of the compartment was - 15℃. The former temperature was all 0.2℃ lower than the latter temperature, when comparing the speed of the evaporator outlet velocity was 4 m/s and 2 m/s, or the thermal conductivity of insulating materials was 0.05 W/（m-K） and 0.033 W/（m· K）, and the door was opened in the 6 min, and the initial temperature of the compartment was 0℃. Besides, the air-temperature increased more correspondingly inside refrigerated compartment in the situation of big temperature difference between interior and exterior and wider dooropening. Lastly, the interior heating rate was different according to the wind and wind direction outside of refrigerator carriage with the door opened.