Study On Key Technologies Of Energy-saving Devices For Smoke Ovens Based On CFD

With the improvement of the material level of modern society,the demand for smoke food in the domestic market is also growing.The smoke oven is an important machine for food processing.It's processing properties and innovative design have a large impact on the market share of smoke oven products.Nowadays,energy saving and emission reduction have become an important development direction of food machinery.However,at present,smoke ovens in the smoke food industry directly emit hot exhaust gas,and the rest of the research on heat recovery and energy conservation devices is still blank.Therefore,research on energy-saving devices for smoke ovens has important theoretical and practical significance.Based on the theory of computational fluid dynamics and heat transfer,this paper uses the combination of numerical simulation and experimental verification to study the key technologies of the energy-saving device of the smoke oven.The main work and achievements of the thesis are as follows.(1)Based on the basic principle of heat exchange,the concept of energy-saving device for smoke oven is proposed.The design scheme of the energy-saving device is given for a common smoke oven,and the basic function and interface technologies of plug-in energy-saving device are discussed.The principle of the energy-saving device is to collect the hot exhaust gas directly discharged into the air from the smoke oven,and then use it to preheat the fresh air entering the heating chamber.Two different schemes of tube and plate are given for the core waste heat recovery parts of energy-saving devices.The overall assembly model of energy-saving devices is established by using 3D geometric modeling software.(2)Through the reasonable simplification of the designed energy-saving device,the simulation model of the airflow temperature field of the key components of the waste heat recovery of the energy-saving device is established.The initial boundary conditions of thesimulation model are obtained by detecting the wind speed of the exhaust port and the fresh air inlet under the working condition of the smoke oven under study.Based on the established model,the CFD technology is used to simulate and solve the temperature field,flow state and heat transfer effect of two different schemes when the energy-saving device is working stably.The residual heat recovery efficiency of the two schemes is compared and analyzed.(3)The heat recovered by the energy-saving device is the optimization target.Considering the vertical spacing and horizontal spacing of the heat exchange tubes,the thickness of the return air box and the presence or absence of added small tubes are optimized variables,the optimized mathematical model for optimizing the structural size of the waste heat recovery components is established.Using orthogonal optimization method,two orthogonal optimization combinations of small tube and no small tube are calculated respectively,and two sets of optimal parameters are obtained,which provides reference for the design of waste heat recovery parts of energy saving device.(4)According to the optimization results,the prototype of the energy-saving device is manufactured,the experimental plan is designed and the experimental platform is built,detecting the temperature and speed of the airflow of the inlet and outlet of the energy-saving device.The simulation data and experimental data are compared and analyzed to verify the accuracy of the simulation results and the effect of waste heat recovery of the energy-saving device.In summary,this paper studies the key technologies of the smoke oven energy-saving devices.That is to say,the interface technology of the smoke oven energy-saving device,the heat recovery technology of waste heat recovery,and the CFD-based simulation modeling(including optimization modeling)technology are studied.Two different structural schemes of tube and plate are designed for the core components of waste heat recovery of energy-saving devices.The heat transfer simulation model is established to simulate and calculate the heat transfer effects of the two schemes.The change of recovery performance of waste heat recovery components under different structural parameters is studied.The optimization mathematical model is given.The optimal parameter combination is obtained by orthogonal optimization.Finally,the accuracy of the simulation is verified by experiments.The research work in this paper is conducive to promoting the research on energy saving and emission reduction of the smoke ovens,and improving the recycling of waste heat.