Numerical Simulation Of Dry Pulverized Coal Y Swirling Entrained Flow Gasifier

In our country,coal as the main energy position to support the development of the national economy will be difficult to shake in a long time.How to rely on China's relatively abundant coal resources to ease the contradiction between supply and demand of energy has important practical significance.The strategic development direction of China's energy transformation is to realize the scale of non-fossil energy and the cleanliness of fossil energy,while the latter is more important,especially the clean utilization of coal.As the core technology of clean and efficient use of coal,entrained-flow gasification technology has gradually become a research hotspot in coal gasification and has been rapidly developed.This paper aims at solving the short particle residence time,the difficult separation of ash residues,and the development of modern coal gasification technologies that contain salty wastewater in the existing coal gasification technology,Concerning the problem,the concept of dry pulverized coal Y-type swirling flow entrained-bed gasifier was put forward,and the technical principle and advantages of the new-type swirling gasifier were introduced in detail.Using a numerical simulation method,a swirl gasifier model was established using Gambit 3D modeling software,and the flow field was calculated using several Fluent software.T he gas-solidification of the cold flow field of the gasifier when the number,height,and angle of the sub-nozzles were critically examined.The characteristics of two-phase mixing and speed,temperature,turbulent kinetic energy.distribution of molar concentration of each component,and performance of cold ons efficiency in hot state operation.The cold state simulation of the uasifier shows that the height and angle of the secondary nozzle determine the turbulence intensity in the gasifier,the size of the recirculation zone.the ddegree of gas-solid two-phase mixing,and the particle residence time;when the number of secondary nozzles is three,The flow ratio between top nozzle and sub-nozzle is 2:1.L/D is 0.7.Secondary nozzle angle is 10°the How field distribution is the most reasonable.and the particle residence time is the longest,which is the best furnace type structure.Thermal simulations show that the materials injected into the gasifier top nozzle and side nozzle are swirled and violently mixed in the upper part of the gasification chamber to form a stable high-temperature zone of turbulent flame,fully utilizing the gasifier's effective reaction space,and the material rotation movement prolongs the residence reaction time.The carbon conversion rate has been greatly improved?Simultaneously,The total coal supply is designed to be 10t/h,the oxygen to coal ratio is 0.8kg 02/kg(coal),the gas to coal ratio is 0.16kg H2O/kg(coal),and the components in the synthesis gas are released when the gasification pressure is 3MPa.The concentration distribution is reasonable.The composition of CO in the export synthesis gas is 57.7%in molar composition,31.2%in molar composition of H2,0 in CH4,6.7%in CO2 molar composition,and there is a relatively high effective gas(H2 and CO)content,in line with the expectation.It validates the advantages and practicability of the furnace type,and provides a solid foundation for process design and development,and has a good guiding role for future industrial application.