高炉烧结中烟灰在换热器中的积灰特性研究
The Experimental Study of Ash Deposition Properties in Heat Exchanger Test Unit after Flow through High-Temperature Flue Gas Is Generated in Blast Furnace Ironmaking

高炉炼铁中产生大量的高温烟气，余热资源利用潜力巨大。但利用过程中往往会因烟气中的灰尘颗粒沉积在烟气换热器翅片表面，导致换热性能下降，影响烟气余热回收利用。为减少积灰的不利影响，了解灰分在换热器翅片表面的沉积特性十分必要。本文设计并搭建了烟气换热器试件积灰实验台，选取2个波纹翅片管换热器为试件，在190℃、空气流量0.05 kg/s、海拔1500 m，相对湿度12%，892.1 mg/m³灰分浓度、3小时工作条件下进行实验，研究烟气换热器翅片表面灰分沉积特性。研究表明灰分主要堆积在迎风面的翅片前缘、背风面翅片和换热管的背风面上，两个试件分别增加3.91 g、8.72 g。试件上的灰分沉积率分别为0.699%、1.27%。
A large amount of high-temperature flue gas is generated in blast furnace iron making, and there is a huge potential for the utilization of waste heat resources. However, during the utilization process, ash particles in the flue gas tend to be deposited on the surface of the fins of the flue gas heat exchanger, leading to a decrease in heat transfer performance and affecting the recovery and utilization of waste heat from the flue gas. It is necessary to understand the deposition characteristics of ash on the surface of heat exchanger fins in order to reduce the adverse effects of ash accumulation. This article designed and built an experimental platform for ash deposition on flue gas heat exchanger specimens. Two tube bank fin heat exchangers were selected as specimens, and the experiments were carried out at the conditions that the flue gas temperature is 190 °C, the air mass flow rate is 0.05kg/s, the altitude is 1500m, the relative humidity is 12%, the dust feeding speed is 0.07g/s, the ash concentration is 892.1 mg/m³, and the operating time is three hours. The ash deposition characteristics of the fins surface of the flue gas heat exchanger were studied. The results show that ash mainly deposits on the leading area of the fins on the front side of the heat exchanger and on the leeward side of the fins and the tubes in back side of the heat exchanger, with the mass increase of 3.91g and 8.72g for the two specimens, respectively. The ash deposition rates on the specimens are 0.699% and 1.27%, respectively.