Optimization And Intelligent Control On Temperature Distribution Of Refrigerated Truck

With the rapid development of national economy and the continuous improvement of living standards,people have higher and higher requirements for the quality of fresh food,medicine and other products.Cold chain is an important way to transport and distribute such goods.And refrigerated truck is the main tool for short-distance transportation and distribution of perishable products in cold chain,and it is an indispensable part of cold chain system.However,for the existing refrigerated trucks,the temperature distribution in the compartment is uneven,the temperature control effect is poor,and the degree of intelligence is low,these seriously limit the transportation capacity of the refrigerated trucks.This paper takes the single-temperature refrigerated truck as the research object,analyzes the distribution characteristics of the temperature field inside the compartment,proposes an optimization scheme and a control scheme,and studies the reasonable refrigerated compartment air supply method,control method and intelligent control system.Aiming at the single temperature area refrigerated truck,a mathematical model and a simulation model of the refrigerated compartment are established.The internal flow field conditions at no load were obtained through numerical simulation and experimental verification.The cold air forms a circulation in the refrigerated truck.The flow direction of cold air is centralized,which is not conducive to the overall cooling of the carriage.On this basis,a cascade air supply scheme is proposed to optimize the temperature field.Add fans at the top of the car to make the direction of cold air flow more dispersed.The distribution of temperature field before and after optimization is compared by numerical simulation and experiment.The results show that the cascade air supply system can effectively reduce the average temperature of the carriage,non-uniformity coefficient of temperature field in the refrigerated truck,the difference between the highest temperature and the lowest temperature and increase cooling velocityAiming at the traditional refrigerated compartment cooling method,based on the existing refrigeration equipment,a fast and accurate temperature control scheme for the refrigerated compartment temperature field is proposed.PID control algorithm is used to adjust the air supply speed of evaporator steplessly.The mathematical model of temperature change in refrigerated compartment is established,and the parameters of PID algorithm are optimized by genetic algorithm.Compared with the ordinary PID algorithm,the optimized PID algorithm can achieve smaller temperature fluctuation and faster temperature regulation speed,and the temperature regulation in the carriage is faster and more accurateThis paper analyzes the characteristics of refrigeration equipment and operation environment of refrigerated truck,puts forward the local and remote monitoring scheme of temperature field in refrigerated truck,and develops the intelligent monitoring system of temperature field in refrigerated truck.The local monitoring system mainly includes thermocouple,PLC and touch screen,and the remote monitoring system mainly includes the establishment of cloud server,database and mobile app.The two subsystems together form an intelligent control system for the temperature field of the refrigerated compartment.This system has the function of automatic and precise control of the temperature in the cabin,and realizes the local monitoring and remote real-time monitoring of the temperature field in the refrigerated compartment.