Study On Simulation Of Microenvironment And Monitoring System In Refrigerated Trucks

The demand of agricultural products including the processed products of them is increasing according to the market.In this context,refrigerated trucks play more important roles as professional conveyances providing service of transporting products that have special requirements of freshness.China is a large agricultural country,however,a great quantity of agricultural products and foods cannot be transported in time every year resulting in serious wasting and economic losing since the refrigeration technology is under developing.What’s more,refrigeration technology in China developed late so that the technology is under developing.Nowadays only temperature is detected in refrigerated trucks in China due to the lack of emphasis on the other parameters in refrigerated trucks which has caused problems of lack of data of velocity and volume so that the volume of air output by refrigerator cannot be controlled effectively.Therefore a design of wireless networking for sensors of velocity and volume of air is raised to solve the problem with support of Tianjin Food Safety and Low Carbon Manufacturing Collaborative Innovation Center and the project "Information Sensing of Microenvironment in Refrigerated Trucks and Intelligent Controlling Equipment" supported by National Science and Technology Ministry.Improper installation could cause problems in temperature controlling,leading to the uneven distribution of temperature field.It may cause problems to the transported products.According to the CFD,the paper built the model inside the carriage of a refrigerated truck and researched on the influences on the temperature field by the velocity field when the refrigerated truck work regularly.Then the paper designed the installation scheme of sensors to detect temperature properly in multiple positions.At last the paper designed the wireless monitoring system with the technology of ZigBee.The system was designed to monitor the parameters in the refrigerated trucks.The system consists of wireless velocity and volume sensors,wireless temperature and humidity sensors and a tablet computer which is installed in the driver’s cab.The velocity and volume sensors are installed in front of the outlet of refrigerator so that they could detect the parameters in real time properly.The temperature and humidity sensors are installed at the top of the carriage averagely so that they could detect the parameters in real time properly.The data of velocity,volume,temperature and humidity is transmissed to the upper monitor made of tablet computer via Bluetooth.The upper monitor locates in the driver’s cab and it displays the parameters in real time.Also the upper monitor could store and query data.