Study On Temperature Field And Pressure Field Of SJ Low-temperature Drying Furnace

The northern region of Shaanxi is an important jurassic coal producing area in China.Non-stick,and low-rank long-flame coal in this area are dried through SJ-type internal retorting furnaces to obtain blue charcoal,tar,and coal gas.This a main process to keep clean and efficient use of coal.This article takes a 50,000-ton SJ-type carbon retorting furnace as the research object.The main research contents and conclusions are as follows:(1)Collect factory production data,use 1000 kg of coal into the furnace as the calculation standard,carry out the material balance of the revenue item and the expenditure item on the carbonization furnace and analyze the error,and then calculate the heat distribution in the furnace on the basis of the accounting,and obtain the coal char Ratio,thermal efficiency,etc.,and analysis of thermal performance.Research indicates: the error of the material balance of the dry distillation furnace is 0.28%,which is lower than the maximum allowable error range of the material balance by 1%,the coal coke ratio is 1.39:1,and the thermal efficiency is66.56%.The thermal efficiency can further improve be enhanced through heat preservation measures and heat recovery.(2)Using ice software ANSYS pre-processing software,according to the actual size of the SJ-type low-temperature dry distillation furnace for three-dimensional modeling and meshing,using the standard k-? model to simulate the flow of gas in the furnace,The finite-rate/vortex dissipation model was used to simulate the combustion of the mixture in the furnace.The P1 radiation model was used to simulate the heat transfer process in the furnace.The porous medium model was used to substitute the coal seam in the furnace cavity and the mathematical model of the SJ furnace was established.Study the temperature field and pressure field of 8 types of coal particles such as 40 mm,35mm,30 mm,25mm,20 mm,15mm,10 mm,and 5mm,and compare them with actual industrial production: 10~60mm,10~30mm,5~30mm,3 Comparison of 5 working conditions of ~30mm and 0~30mm.Research indicates:when the particle size of coal entering the furnace is greatly changed,the temperature in thefurnace decreases,the pressure increases,and the volume fraction of the retorting area decreases gradually.However,the distribution trends of the flow field at different particle sizes are similar,and the maximum temperature in the furnace decreases approximately linearly.The maximum pressure increases approximately exponentially;under the same particle size,as the height of the coal seam in the furnace cavity gradually increases,the temperature difference at the same height gradually decreases.The numerical simulation results show that the temperature error is less than 6.25% and the pressure error is lower than12.8%.(3)Set up a two-dimensional model of the retorting furnace,taking the coal particle diameter D=20mm as an example,to study the temperature and pressure fields of the dry coke quenching technology for blue carbon before and after quenching,and for different amounts of water spray,and to obtain a suitable spray.Water volume range.The results show that the flow field in the furnace after dry coke quenching of blue charcoal shows a trend of lowering the pressure and the quenching water quantity is controlled to be 1.1~1.2m3/h.