Simulation of Deposition and Flow Characteristics of Slag in Entrained Flow Gasifiers

Abstract

Water-wall entrained flow gasifiers ensure long-term safe operation using the idea of "fighting slag with slag". Thus, wall slagging is essential for the operation of gasifiers. The gasification process of dry coal power was simulated in the entrained flow gasifier by ANSYS Fluent software for this study. The eddydissipation concept model has been used to simulate the homogeneous reaction process in the gasifier. The unreacted core shrinking model has been used to simulate the heterogeneous reaction. The discrete phase model has been used to simulate the interaction between the gas phase and particles. The Yong model determines the adhesion of particles on the wall, and the Seggiani model describes the slag flow on the wall using a user-defined function compiler. The slag flow in the gasifier was simulated at an operating temperature of approximately 1750 K. The results show that the deposition flux of ash particles reaches a maximum value of 0.32 kg/m 2 s at 2.5 m below the gasification burner, and the deposition flux at the lower slag mouth remains at 0.08 kg/m 2 s. The maximum thickness of the liquid slag and total slag layers reach 14.4 and 62.7 mm, respectively.

Numerical Simulation of the Integral Thermal Deformation Behavior of a Radiant Syngas Cooler for an Entrained-Flow Gasifier

“…The 1/8 structure is used for the analysis due to the symmetry of the RSC. The temperature of the upper cone membrane exceeds 800 K because of the recirculation zone at the inlet jet of the upper part. , The high-temperature syngas is entrained at the upper part of the RSC, which comes into contact with the upper cone membrane wall, resulting in a high-temperature area on the upper cone membrane wall. The upper part of the cylinder membrane wall is affected by the recirculation zone, which is complicated for the flow of high-temperature syngas.…”

“…Previous studies have primarily concentrated on the processes of flow, heat transfer, and ash deposition in the RSC, − while the thermal deformation behavior has rarely been studied. However, in industrial operations, the thermal deformation of the top sealing structure causes local overtemperature and sealing looseness, leading to system shutdown in emergency cases, which directly impacts the safe and efficient operation of the gasification system.…”