【作者】 姚雪峰；

【导师】 俞秀民；

【作者基本信息】 湖南工业大学 ， 机械设计及理论， 2008， 硕士

【摘要】 炼铁高炉的寿命取决于冷却设备的寿命。而水垢对冷却壁寿命的影响是第一位的。铜冷却壁整体导热性好,必须配备软水密闭循环冷却系统才能防止流道内壁结垢,一代炉役可达15～20年,但投入巨大且运行费用高昂。本文研究旋液流态化冷却壁新技术,其技术原理是在冷却水流道内设置钢丝螺旋线使冷却水呈螺旋轨迹流动。需要清洗水垢时,加入体积比为2%流态化粒子,粒子随冷却水在流道内螺旋前进,由于离心力的作用,大部分粒子都沿流道内壁的圆柱面螺旋流动,使冷却水流道内壁水垢得以快速、均匀清洗。因而,该冷却壁整体导热性可大幅提高。本文首先对其核心技术旋液流态化进行了试验研究,结果表明:流道的人工水垢清洗时间只需145秒。另外,其对流传热强化幅度可达50%以上,而流体总阻力48.7kPa低于供水压力。作者采用理论计算、数值模拟和试验相结合的方法进行研究。传热学理论计算表明,该冷却壁的总传热系数是铜冷却壁的40.7%,是铸铁冷却壁的14倍,是普通铸钢冷却壁的5.1倍。数值模拟时,在GAMBIT中建立求解模型,使用FLUENT的离散项模型和三维稳态分离求解器对旋液流态化的传热强化幅度和冷却壁温度场进行模拟。数值模拟结果表明:与空管相比,旋液流态化的对流传热强化幅度为40.4%;肋板完全磨损后,即使热面无渣皮,其热面最高温度也会低于安全温度;无肋板且热面均匀粘结30mm厚渣皮时,壁体热面最高温度仅为85.7℃。首次研究提出了排渣道内进行的模拟试验技术,以测定冷却壁热面最高温度和渣皮形成过程及分布。该方案具有试验周期短、费用省、易于操作且安全可靠等显著优点。更多还原

【Abstract】 The service campaign of blast furnaces depends on their cooling equipments’campaign. The water fouling is the most important factor in service campaign of cooling staves. Copper cooling staves have excellent quality of total heat transfer. With closed loop soft water cooling systems applied, their service campaign is up to the level of 15 to 20 years, but they cost huge.The cooling stave intensified by spiral fluidization is studied on in the paper. The technical principle of spiral fluidization lies in installing spiral steel wires within flow channels, which guide cooling water flowing in spiral streamline. The fluidization particles with volume concentration of 2 percent are injected in need of cleaning. When cleaning, the particles flow spirally together with cooling water. Most of particles flow spirally on cylindrical surfaces of flow channels with the action of inertial centrifugal force. So the water fouling is removed quickly and uniformly. Experimental researches on spiral fluidization, the core technology of the stave, are performed for the first time in the paper. And their results show that it only costs 145 seconds to remove the artificial fouling on inner walls of flow channels. In addition, they also reveal that convective heat transfer coefficient between cooling water and inner walls is intensified for more than 50 percent, and that the total flow resistance is equal to 48.7kPa which is lower than total pressure of supply water.The method of theoretical calculation combining with numerical simulation and experiment is applied while researching. The results of theoretical calculation based on heat transfer show that the total heat transfer coefficient from inner wall of cooling tube to hot surface of the stave is 40.7 percent of copper stave’s, 14 times of cast-iron stave’s and 5.1 times of widely-used cast-steel stave’s. While simulating, solution models are created by GAMBIT, and by FLUENT are performed numerical simulation on heat transfer magnitude intensified by spiral fluidization through discrete phase model and temperature field of the stave through 3-dimension steady segregated solution. Results of numerical simulation show that in comparison with tubes without any inserts in, the enhanced magnitude of convective heat transfer is up to 40.4 percent. They also reveal that it is under safety temperature during the stage with fins worn down completely even if there is no slag sticking on hot surface, and that the highest temperature on hot surface is only 85.7 degrees on the condition that a layer of slag thick 30mm uniformly sticks on it.In the end, an experimental theme in thermal simulation, performed in slag notch, is researched and put forward for the first time to test the temperature on hot surfaces, period of forming slag and distribution of slag. It has many remarkable advantages such as short test period, low cost, easy operation, safety and reliability, and so on.更多还原