Study On Simulation Research On Airflow Organization Of Elevated Cold Storage

With the rapid development of cold chain logistics market,the number of cold stores is increasing,and elevated cold stores emerge.Elevated cold storage is concerned for its large storage capacity,low cold consumption and low operation cost.At present,the built elevated cold storage mainly adopts two kinds of air supply modes air cooler or fiber air distribution system,the selection of air distribution design scheme is random and blindly copied.Therefore,the research in this paper is of great significance to the air distribution design of the elevated cold storage.In this paper,numerical simulation software is used to establish a three-dimensional heat transfer numerical model for an elevated cold storage in Yushu,which adopts the air cooler and fiber air distribution system,the porous medium model is used for the cargo area,and the formula is used to verify the correctness of the models.Comparing the effects of different air supply modes,the storage volume of goods,the jet penetration ratio of air duct and the air temperature on the air distribution,the best scheme is obtained.The main research contents are as follows:By using fiber air distribution system or air cooler,the dynamic cooling process of goods is simulated,and the air distribution and cooling law at different cooling time are obtained.The results show that the temperature gradient is small,the air supply speed is low and the cooling time is reasonable under the fiber air distribution system;the temperature gradient in the warehouse is large,the air supply speed is large and the dry consumption of goods is large under the air supply mode of air cooler.Fiber air distribution system is the best air supply mode for elevated cold storage.Aiming at the elevated cold storage with fiber air distribution system,the air distribution in the cold storage is simulated with different storage volume of goods and different jet penetration ratio of air duct,and the influence of storage volume and jet penetration ratio on the air distribution is obtained.The results show that with the increase of the storage volume of goods,the blocking of cold air is more obvious.When the storage volume accounts for 12% of the total storage capacity,the distribution of air distribution is the best;when the jet penetration ratio of air duct is 9:1,the standard deviation of temperature is small,the distribution of temperature field is uniform,and the efficiency of waste heat removal is high.Aiming at the elevated cold storage with fiber air distribution system,the unsteady simulation calculation of air distribution in the storage is carried out from different supply air temperature,and the influence law of supply air temperature on the dynamic cooling process in the storage is obtained.The results show that the lower the supply air temperature is,the higher the cooling rate of the goods is;the higher the supply air temperature is,the more uniform the temperature field in the storage is;when the supply air temperature is 2 ℃ lower than the design temperature,the air distribution effect in the warehouse is the best.Through the study of air distribution characteristics and cooling time,the superiority of fiber air distribution system in the elevated cold storage is verified,the research results of different cargo storage volume can be used as a reference for the operation and management of cold storage,the research results of different air duct injection penetration ratio and different supply air temperature have theoretical significance for the air distribution design of elevated cold storage.