Research On Energy Saving Optimization Of Small Cold Storage Based On CFD

In recent years,the modern refrigerated logistics system has developed rapidly.As the basis for ensuring the quality and safety of goods,the cold storage is the main facility of the refrigerated logistics systems.In China,cold storage is also considered to be a big consumer of electricity,so energy saving in cold storage is increasingly valued.In a forced-circulation air-cooled cold storage,the reasonable placement of the air cooler in the cold storage and the wind speed of the fan are particularly critical.On the other hand,the way of goods placed in the cold storage has a greater impact on the rationality of the airflow in the storage and the cooling curve of the goods.This article studies the placement of the goods in the warehouse under the best pre-cooling method to ensure that all goods in the warehouse are cooled evenly to achieve rapid and balanced freezing.At the same time,a multi-channel working data acquisition system was designed for the cold storage,and the experimental data and the simulation results are basically consistent.The main research contents of this paper are as follows:First,based on CFD technology,physical models of small cold storage fans under different positions are established,taking into account the convection heat transfer at the warehouse door,and using standard k-εturbulence model and unsteady state calculation methods to solve different models.This paper analyzes the temperature field and the air flow rate in the warehouse at different times under different fan placement methods.The steady-state simulation of the different wind speeds of the wind turbines under the mode of placing the wind turbines facing the warehouse door is carried out,and the flow field and temperature field in the warehouse under different wind speeds are analyzed.Numerical simulation shows that among the three fan placement methods,the fan and door are placed relative to each other,and the temperature in the library is uniformly cooled faster.When the library reaches a steady state,the fan speed is 9.3m/s,which can make the surrounding temperature in the library also tend to be consistent.This way of working can achieve rapid and balanced pre-cooling of the empty warehouse,so as to achieve the purpose of energy-saving optimization.Second,modeling and analysis were carried out for the different placement of goods in the target cold storage.In the simulation,the goods were set as the solid heat source item,and the surface of the goods and the airflow in the storage were calculated by convection and conduction coupling.Analyze the internal temperature field,flow field,and cooling curve of the cargo side of the cold storage in different ways of placing the goods.According to the numerical simulation results,it can be seen that when the cargo interval is 0.1m,the height of the cargo exceeding the air outlet of the air cooler has a greater impact on the cooling of the cargo.Therefore,in the target cold storage,the non-layered goods will cool down the fastest and evenly when the goods are placed facing the fan.Finally,through the multi-point temperature measurement during the pre-cooling process of the cold storage,the numerical simulation results of the relative placement of the fan and the door are experimentally verified.Real-time data acquisition is performed on the operating status of the target cold storage,and a set of multi-channel data acquisition system based on RS485 bus is designed to complete the real-time monitoring of the temperature,suction pressure,outlet flow and other working conditions of the target cold storage.Early warning of abnormal data reduces the hidden dangers of equipment operation safety.Based on the collected data and the numerical simulation result data,the results of the experiment show that the best fit between the temperature curve of a single point in the library and the curve of the numerical simulation temperature value is R~2=0.96;the temperature values measured at different points in the library at the same time are compared with each other.The maximum difference of the numerical simulation temperature value is 1.46℃.