Method for establishing and simulating aerobic composting model

Abstract

The invention relates to a method for establishing and simulating an aerobic composting model. The method comprises the following steps: 1) establishing the aerobic composting model; 2) according to a ''mass-heat-momentum'' coupling transfer mechanism in an aerobic composting reaction process, assuming the aerobic composting model, calculating entrance and exit flow velocity according to an entrance mass flow rate, and utilizing a dimensionless Reynolds number to judge that a fluid movement state is turbulence; 3) according to the Fick law, the Fourier law and a k-Epsilon turbulence equation, constructing a mass transfer equation, a heat transfer equation and a momentum transfer equation; 4) determining the boundary condition of the aerobic composting model; 5) determining an initial condition, and carrying out geometric modeling and mesh generation on a specific model object on an ANSYS platform according to the steps 1)-4); and 6) utilizing a CFD (Computational Fluid Dynamics) Post module to carry out simulation calculation on the aerobic composting model in ANSYS FLUENT to obtain an aerobic composting simulation model. The method can describe the problem of the spatial distribution of temperature and oxygen concentration in an aerobic composting reaction process.

Description

technical field [0001] The invention relates to a model establishment and simulation method, in particular to an aerobic composting model establishment and simulation method based on mass-heat-momentum coupling transfer. Background technique [0002] At present, aerobic composting is the use of solid waste such as kitchen waste, livestock and poultry manure, and crop straw for microbial fermentation. The process mainly uses microorganisms to decompose organic matter into simple compounds, and the heat generated can kill pathogenic bacteria, parasite eggs, and other impurities. Grass seeds, finally obtain stable humus organic fertilizer treatment process. In the process of aerobic composting, sufficient oxygen concentration ensures the activity of aerobic microorganisms and reduces anaerobic fermentation. A certain high temperature can kill harmful bacteria and insect eggs in the compost, so the monitoring of these two parameters is very necessary. [0003] The numerical mod...

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Problems solved by technology

First-order kinetic model or modified Monod model, this type of model is an empirical or semi-empirical model, the model structure is relatively simple and convenient, and the simulation results are relatively accurate, but the coefficients need to be corrected for different materials or different working conditions, and the wide-spectrum adaptability The performance is not good; the discrete model based on the particle structure, which relies on the mechanism of microbial action, combines the microscopic scale and the particle distribution function, belongs to the mechanism model, and the model has certain adaptability, but due to the different particle distribution and particle structure Deterministic, the simulation accuracy of this type of model is poor

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