Influence Of Atomized Spray Of Liquid Nitrogen Refrigerated Vehicle On Refrigeration Performance

Atomized spray of liquid nitrogen, due to its simple structure, beneficial characteristic,environmental protection and atmosphere-controlled function, is widely used in the field of liquid nitrogen refrigerated trucks and has broad market prospects. This paper is based on the theory of liquid atomization, utilizing the research method as numerical simulation as well as experiment, exploring the tendency of atomized spray of liquid nitrogen technique.Utilizing numerical simulation aims to compare the whole property trends within liquid nitrogen refrigeration compartment. This experiment started with the recorded temperature and then analyzed thoroughly the distribution of temperature and the speed rate of reducing temperature within the refrigerated compartment.This article mainly focuses on the following aspects:1. Numerical simulation: Through changing the inlet pressure of diameter 1.5mm spray holes, the interval of holes and wind pressure, this article compares and analyzes the distribution cloud images of temperature field, concentration field, and velocity field, and then analyzes the relationship between three parameters and characteristics of liquid nitrogen refrigeration compartment.2. Experiment: According to certain statistics, this article analyzes the distribution of temperature within liquid nitrogen refrigeration compartment. Due to non-adjustable pressure of liquid outlet in self-pressurized liquid nitrogen tank, the input pressure of spray holes can not adjust itself. Utilizing diameter1.5mm spray holes and 1.5mm hollow cone nozzles as control experiment, the experiment chooses a better and effective spray model to change wind pressure, the interval of spray and compare the distribution of temperature and speed rate of reducing temperature.Through numerical simulation, it can be seen as follows:1. The larger the fan pressure is, the more obviously the forced convection effect shows within refrigerated compartment. But when fan pressure becomes overload, it will block the effect of atomized spray of liquid nitrogen in the place where the holes stays.2. To guarantee normal liquid nitrogen spray atomization keeping within pressure range, it can be found that the pressure at the exit of holes becomes, it will contribute more to equal distribution of temperature field, concentration field, and velocity field within refrigerated compartment.3. Under the condition of choosing suitable fan pressure and output pressure of spray holes, the paper found that the closer single row of spray holes are, it contributes more to the distribution of temperature field, concentration field, and velocity field within refrigerated compartment.Through experiment, it can be discovered as follows:1. Utilize atomizer with 1.5mm holes: regardless of fan, atomizing effect does not show clearly and it can only happen once. Temperature field uniformity within refrigerated compartment is not good.2. Utilize atomizer with hollow cone nozzles: within a certain wind pressure range,the faster the wind speed is, the better the distribution of temperature field becomes within refrigerated compartment, but the more slowly the speed rate of reducing temperature is.3. Utilize atomizer with hollow cone nozzles: the closer of sprays use in the experiment, the better the distribution of temperature field becomes and the more slowly the speed rate of reducing temperature is.According to the results shown above, it can be concluded as follows:1. Utilizing atomized spray of liquid nitrogen with 1.5mm holes can achieve better effects than using hollow cone nozzles, and make temperature distribution more equally.But the speed rate of reducing temperature is much slower than that of 1.5mm.2. To guarantee normal liquid nitrogen spray atomization keeping within pressure range, the smaller the input pressure becomes, the better the equal distribution of temperature field, concentration field, and velocity field within refrigerated compartment.3. The closer single row of spray holes are, it contributes more to the equal distribution of temperature field, concentration field, and velocity field within refrigerated compartment and the speed rate of reducing temperature becomes faster.4. The larger the wind pressure is, the faster the wind speed is. it contributes more to the equal distribution of temperature field, concentration field, and velocity field within refrigerated compartment and the speed rate of reducing temperature becomes faster.However, when the fan pressure is overload, it will block the effect of atomized spray of liquid nitrogen in the place where the holes stays.5. In sum, the most effective working condition of atomized spray within liquid nitrogen refrigeration compartment can be described as closer sprays, smaller input pressure of spray, and larger wind speed of fan, whose situation can achieve the best atomizing effect under the pressure of such working conditions.