多温冷藏车降温特性及其影响参数研究

Cooling Characteristics and Influence Parameters of Multi-temperature Refrigerated Truck

摘要:

基于多温区冷藏车厢结构特点，考虑车外综合温度、车辆行驶速度、车厢密封性、冷冻与冷藏区的空气流动规律等因素，建立了多温冷藏车厢内各温区的降温数学模型，并对所建数学模型进行了相应的试验验证，进而分析了多温冷藏车降温性能的影响因素。研究结果发现：制冷降温过程中，冷藏车厢两温区温度均随时间呈指数规律下降；制冷机组制冷量变小、冷藏车厢内货物呼吸热增大、车速升高或者车厢体隔热材料导热系数变大时，两温区降温所需时间均延长；当两温区之间的电动风扇风速或出风口面积增大时，冷冻车厢内降温所需时间延长，而冷藏车厢降温所需时间缩短；当两车厢总体积不变，冷冻车厢体积增大、冷藏车厢体积变小时，冷冻车厢降温所需时间延长，而冷藏车厢降温所需时间基本保持不变；当两温区隔热板厚度发生变化时，两温区降温特性基本保持不变。

Abstract:

Comprehensively considering the construction features of the multi-temperature refrigerated truck and the externalsol-air temperature, vehicle speed, compartment seal and air flow characteristics between the frozen and refrigerated zone of the multi-temperature refrigerated compartment, the cooling mathematical models in the every temperature zones of the multi-temperature refrigerated truck was built up. A testing was conducted to verify the correctness of the mathematical model, and further the impact factors of the cooling performance were analyzed. The study results showed that: during the cooling process in refrigerated trucks, temperatures both in two temperature zones were decreased exponentially with time. Cooling time in both the two zones was increased when the cooling capacity was reduced or the respiratory heat of goods and the vehicle speed and thermal conductivity of the compartment insulation material were increased. Besides, the cooling time will increase in the frozen zone while the cooling time in the refrigerated zone would decrease if we enlarge the fan wind speed between the two zones or increase the wind outlet areas. If volume in the frozen zone was enlarged and volume in the refrigerated zone was decreased with the total volume unchanged, cooling time in the frozen zone would increase while the refrigerated zone keeps unchanged. The two cooling characteristics remained the same when the thickness of the insulation panels between the two temperature zones was changed.