Numerical Design And Experimental Verification Of The Air Duct Structure Of The Self-lifting Freezer

Global cold chain technology with the economic development brought by the people's growing demand for quality and continuous development and improvement.However,the cold chain currently accounts for about 1%of global CO2 production and this proportion continues to rise with the development of the cold chain.In the cold chain,the energy consumption and carbon emission of freezing and refrigeration brought by the terminal equipment are more than 50%,and the environmental problems are increasingly serious.Therefore,it is of great significance for global energy saving and emission reduction to improve the performance of the end equipment such as the self-pickup cold storage cabinet.The fresh-keeping quality and efficiency of the terminal equipment are determined by its internal flow field distribution,so the air distribution in the self-pickup cold storage cabinet is an important factor to improve its thermal environment performance.This paper takes self-pickup cold storage cabinet as the research object.Aiming at the mode of up-supply and up-return air supply,the influence of static pressure space(no return air static pressure space,single supply air static pressure space and double return air static pressure space)on the thermal environment performance of self-pickup cold storage cabinets was explored.The advantages and disadvantages of different sizes(50mm,100mm,150mm)of return air static pressure space were further studied.In this paper,when the static pressure space of single air supply and the thickness of the static pressure space is 100 mm,the airflow distribution in the self-pickup cold storage cabinet is considered to be better.On the basis of this structure,the air duct are further changed,that is,angle of the air supply plate,perforation ratio of the air supply plate and angle of the air return plate.Analysis and comparison of simulation results a better improved structural model was selected from 27 models.Furthermore,the temperature and velocity distributions of the existing and improved models of a company under standard operating conditions are measured and compared with the simulation results,which verifies the accuracy of the simulation results in this paper.Also,the applicability of the improved structure in low temperature environment is tested.And further,the paper puts forward the evaluation indexes of thermal environmental performance-vertical surface temperature/velocity uniformity coefficient and average temperature velocity to evaluate and analyze the simulation and field measurement models of different air duct configuration.The optimal air duct configuration model is selected by the evaluation index data.Numerical simulation and experimental verification results are shown that the air distribution in self-pickup cold storage cabinet is reasonable and the thermal environment performance is the best when the air duct configuration is composed of a single supply static pressure space and a thickness of 100 mm with angle of the air supply plate ?=1.5°,perforation ratio of the air supply plate ?=10% and angle of the air return plate ?=30°.The comprehensive performance of this structure is 32.47%higher than that of the current typical structure,and 21.20%higher than that of the existing model structure of a company in Taizhou studied in this paper.This investigation can work as a reference for the interior design of cold storage cabinet for similar use,like self-pickup cold storage cabinets,refrigerators and display cabinets.