Modeling method for in-furnace ash deposition model based on direct simulation Monte Carlo

Abstract

The invention discloses a modeling method for an in-furnace ash deposition model based on direct simulation of Monte Carlo, and belongs to the field of in-furnace ash deposition predication of thermal power plants. The method comprises the following steps that 1, a computational fluid dynamics method is used for calculating a flow field near an ash deposition sampling point; 2, flow field conditions obtained through calculation are imported into a particle motion equation; 3, a direct simulation Monte Carlo method is adopted for calculating collisions among flying ash particles; 4, wall heat flux is provided through a sampling gun, then a flying ash adherence rate equation is solved, and the deposition process of the flying ash particles on a sampling face is calculated. The calculation result indicates that the constructed in-furnace ash deposition model can accurately predict the deposition rate of the flying ash particles in a furnace, detailed ash deposition inner layer flying ash particle size distribution is given, and dynamic prediction of the in-furnace ash deposition process is successfully achieved.

Description

technical field [0001] The invention relates to a modeling method of an ash deposition model in a furnace based on direct simulation of Monte Carlo, and belongs to the field of ash deposition prediction in a thermal power plant furnace. Background technique [0002] Furnace ash accumulation is a common and difficult problem in the operation of power plant boilers, which greatly affects the safety and economy of boiler operation. At present, in the design of power plant boilers, the method of empirical estimation is mainly used for the ash accumulation problem. How to accurately predict the ash accumulation process in the furnace is the key to realizing energy saving and emission reduction of coal-fired thermal power units. [0003] There are many factors that affect dust accumulation. Two key conditions for ash to occur in a furnace are: first, the fly ash particles are able to collide with the walls; second, these fly ash particles have the proper viscosity to adhere to th...

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Problems solved by technology

Obviously, the empirical parameter model is difficult to accurately describe the ash deposition process. The existing discrete dynamics method can solve the equation of motion of a single particle, so as to track the trajectory of a single particle.

However, when simulating the movement of high-concentration particulate matter with a small particle diameter and a large number of particles, the deterministic method will be powerless due to the high computational load and computer storage requirements.

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