Optimization of cold-plate location in refrigerated vehicles based on simulation and test of no-load temperature field

Abstract: In this paper, we studied the uniformity of temperature field distribution of different cold plate arrangement, and learned the influence of the arrangement of cold plate on the distribution uniformity of temperature field in the carriage, so as to provide basis for further research. In this paper, the unsteady numerical simulation of the temperature field in the no-load refrigerated compartment with three different cold plate arrangements ( cold plate set by top, by side, and partially by top partially by side) was carried for 10 h by computing CFD (computational fluid dynamics ).It was found that the air temperature showed a rising trend from top to bottom in the height direction of the carriage. In the direction of the length of the car, the regional air temperature near the center of the car was lower. The air temperature near the wall was higher, and the temperature gradient was larger. When the cold plates were set on side, the whole compartment temperature was low after 10 hours, and the temperature of each measuring point was in the range of -9.5－-7 ℃. The temperature uniformity was good. When the cold plates were partially set by top and partially set on side, the temperatures of different measuring points were vastly different at the beginning, and the temperature difference was reduced at the end, with the final temperature of each measuring point in the range of -9－7.2 ℃. In this situation, the overall temperature and the temperature differences were slightly better than that with cold plate completely set on top. At the same time, when the cold plates were set on side, the available space of the compartment was small, and there was the risk that there might be collisions between the goods and the cold plate in the operation of the refrigerated vehicle, which might be a threat to the safe transportation of the goods. The available area of the cold plate was larger, but because the cold plates were arranged on the top of the vehicle, the Eutectic liquid will lead to the increase of the center of gravity of the vehicle, and the stability of the refrigerated vehicle in operation could be reduced. The available space and the height of the center of gravity of the compartment with cold plates partially set on top and partially set on side were between the two arrangements above. In view of the above, considering the effect of the arrangement of the cold plates on the goods, the cold plates partially set on top and partially set on side were selected as a priority. Considering the influence of the arrangement of the cold plate on the cargo, the available volume in refrigerated vehicles and the height of center of gravity of refrigerated vehicles, two kinds of cold plate refrigerated vehicles with different cold plates arrangements were prepared. At the same time, after 10 h, the deviation between the measured temperature and the simulated temperature was about 2.5 ℃, which showed that the calculation model can be used to simulate the temperature field in refrigerated compartment. The results provide a basis for improving the arrangement of the cold plate and optimizing the arrangement of the cold plate of the cold plate refrigerated vehicle.