| In recent years,with the prevalence of online shopping,the domestic logistics industry has developed rapidly and medium-and small-sized trucks are increasing.In addition,with the improvement of the people's living standards,the human settlement environment has been increasingly valued,and the corresponding people's requirements for the car's thermal comfort have increased.At present,most vehicles are equipped with mechanical compression air conditioners.There are many problems with such air conditioners,such as large space occupation,increasing the overall weight of the vehicle,affecting the vehicle's dynamic performance,and so on.For truck air conditioners,due to the harsher working environment,the application is more difficult,the cooling effect is very unstable,and the service life is short.It is also prone to refrigerant leakage and environmental pollution.According to statistics,at present,the assembly rate of China's truck air conditioners is only about 15%,and most of them are selected after the users buy a car.Truck drivers often carry out medium and long-distance transportation work.They are exposed to harsh environments for a long time and are very unfavorable to the health of truck drivers and affect the efficiency of their work and the safety of transportation.Therefore,the truck cab environment needs improvement.With the development of spray cooling technology and evaporative cooling technology,the effect of spray cooling technology and the efficiency of evaporative cooling have all been greatly improved.For current problems,this article attempts to apply the spray cooling fan to the truck cab,using a combination of experimental testing and numerical simulation to analyze the cooling effect and feasibility of this application.First of all,consult a large amount of data and domestic and foreign literature,introduce the current status of vehicle air conditioning,spray cooling and evaporative cooling technology research.Secondly,the basic principle of evaporative cooling of spray fan is analyzed,and its heat transfer model and heat transfer mechanism are analyzed.At the same time,several commonly used heat dissipation methods are introduced.The influence of heat dissipation performance on the performance of spray cooling fan is pointed out.And simulation studies provide a theoretical basis.Third,design and install a spray fan,determine the size of the spray fan airvolume,determine the actual cooling effect,analyze the feasibility of spray cooling fan application.Fourthly,FLUENT software was used to simulate the thermal environment of the cabin of a truck equipped with a spray cooling fan.The indoor temperature field and velocity field were analyzed to illustrate the application effect of a spray cooling fan.The influence factors of the spray cooling fan were analyzed by changing the air supply speed and spray volume.Fifth,the temperature,humidity,wind speed,and radiation temperature in the cab are measured in real time,plus the clothing thermal resistance and activity intensity,and the thermal comfort PMV and dissatisfaction percentage PPD are calculated.Analysis of the thermal comfort of the truck cabin where the spray fan is installed indicates that the comfort of the driver's location has been improved.There are 28 pictures,8 tables and 53 references in this paper. |
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