Dynamic characteristics of deposit fracture and impacts of operating pressure during sootblowing in the radiant syngas cooler

Abstract

During the operation of entrained‐flow gasifiers, the ash deposits located on the wall tubes in the radiant syngas coolers (RSC) reduce the heat transfer efficiency. Syngas sootblowing is an effective method to remove the slag deposits in the RSC. In this study, a 3D numerical model was developed by combining the cohesive zone method (CZM) and the coupled Eulerian–Lagrangian analysis to investigate the deposit fracture process in RSC during sootblowing. The quasi‐static analysis using ABAQUS obtained the stress–strain curve of the slag sample, which agreed well with the experimental tests and provided the detailed mechanical parameters to the CZM model. The dynamic characteristics of deposit fracture were discovered. The main fracture occurred between 1.0 and 1.5 ms, and the shape of the fracture area was not round but elliptical. The RSC operating pressure (P) was also investigated. The study found that higher pressure led to lower fracture speed, longer sootblowing time, and more syngas consumption. Based on the same extent of deposit fracture, syngas consumption increased when P < 3.5 MPa, and the density of syngas (ρsyngas) has a more significant influence on the syngas consumption than the velocity of sootblowing syngas flow (vavg), especially when the sootblowing time is small.

Simulation analysis of instantaneous impact on the radiant syngas cooler by rapping vibrators

“…Moreover, the numerical model was developed to obtain the dynamic characteristics of the deposit fracture in the RSC, and the effects of the RSC operating pressure (0.1–4.5 MPa) on the slag fracture and syngas consumption were obtained. [ 23 ]…”

“…Moreover, the numerical model was developed to obtain the dynamic characteristics of the deposit fracture in the RSC, and the effects of the RSC operating pressure (0.1-4.5 MPa) on the slag fracture and syngas consumption were obtained. [23] As to the research methodology, instantaneous response analysis (IRA) is a new tool to analyze the transient behaviour under the external excitation. Wu [24] studied an inclined plate with the effects of inertia force, Coriolis force, and centrifugal force and found significant influences by moving-load speed, inclined angle, and the total number of the moving loads based on instantaneous dynamic responses at any instant of time.…”

Experimental investigation of the strength characteristics of low‐temperature fouling containing ammonium bisulfate in boilers

“…However, fewer studies were focused on the characteristics of low‐temperature fouling strength, which is an essential indicator for soot blowing will determine the required medium pressure and the required operating time 15,36 . Noteworthily, the ABS‐bearing low‐temperature fouling usually is difficult to be swept away by the soot blower due to the high viscous and high deposit strength 14,37 .…”

“…10,12,[33][34][35] However, fewer studies were focused on the characteristics of low-temperature fouling strength, which is an essential indicator for soot blowing will determine the required medium pressure and the required operating time. 15,36 Noteworthily, the ABS-bearing low-temperature fouling usually is difficult to be swept away by the soot blower due to the high viscous and high deposit strength. 14,37 Reducing the intensity of low-temperature fouling can improve the ash removal rate by soot blower, reduce soot-blowing duration, and effectively ensure the normal operation of boilers.…”