Flow Simulation And Structure Optimization Of Convection Oven

As a convenient kitchen appliance,the oven has been gradually popularized in our country.Further improving the temperature uniformity inside the oven has always been the goal of many domestic and foreign manufacturers.Solving the problem of inhomogeneous distribution of internal temperature and partial heat accumulation is one of the most important issues in the field of ovens analysis.The solutions include the introduction of forced convection structure and the optimization of heat tube structure.Hot air circulation structure design and assessment of temperature uniformity are the key issues,especially for forced convection heating oven.Focusing on this problem,a forced convection oven is studied in this paper.The internal flow and temperature distribution were numerically simulated and experimentally studied,and the temperature uniformity was evaluated.Finally,the structure optimization design and experimental verification of the oven were carried out aiming at realizing the temperature uniformity.Firstly,the structure and flow heat transfer principle of forced convection oven are introduced in this paper.Its interior consists of three layers of heating tubes and circulation fans,forming a 3D hot air circulation system.The heat transfer mode combined with convection heat transfer and radiation heat transfer is realized to make the baking more uniform,thorough and rapid.Secondly,based on CFD numerical simulation,the internal flow and heat transfer characteristics of the oven are studied,and the distribution of internal space flow and the uniformity of temperature distribution are emphatically analyzed.Through the experiment and simulation,it is found that the temperature distribution of original oven is not uniform and the reason is the existing of large scale vortex in the hot air circulation of the original oven which has a bad influence on the convective heat transfer effect.In order to improve the temperature uniformity inside the oven,three kinds of air duct structures,namely radial guide vanes,grid type wind deflector and new grille are proposed to eliminate the large-scale vortex.Besides,the air duct structures were also optimized.The results show that the uniformity of temperature distribution in the oven cavity of the new 20 degree gridded windscreen structure has been greatly improved.The internal temperature deviation has dropped from 4.63 ? to 1.81 ?.Based on this,two kinds of double-fan structure schemes are introduced to solve the deflection problem caused by single fan rotation.The simulation results show that it can further improve the oven temperature uniformity.Finally,the experimental analysis of the forced convection oven prototype before and after the improvement was carried out.The influence of the hot air circulation structure on the temperature uniformity inside the oven was analyzed,and the improvement effect of the forced convection oven was verified.In this paper,the optimized design of a forced convection oven has achieved remarkable effect in improving the uniformity of temperature.It has been successfully applied to the new products of the oven and brought to the market.The results show that improving the hot air circulation structure is an effective way to improve the temperature uniformity inside the forced convection oven.The research results have an application value to the kitchenware industry.