Simulation method and device of combustion characteristic generation numerical value of utility boiler pulverized coal under variable over fire air volume

Abstract

The embodiment of the invention discloses a simulation method and device of a combustion characteristic generation numerical value of utility boiler pulverized coal under a variable over fire air volume, and solves the technical problems that the whole rule characteristics of combustion, flowing and heat transfer in a furnace can not be measured since the manufacture of the testbed of a full-size model is unrealistic because the size of a hearth is larger and larger at present. The method comprises the following steps of: on the basis of a base conservation equation, a turbulence flow model, a turbulence gas-solid two-phase flow model, a gas phase turbulence combustion model, a pulverized coal particle combustion model, a radiation heat exchange model and a NOX generation model, simulating the boiler pulverized coal in a preset boiler combustor model subjected to mesh generation in a combustion process under a condition of variable over fire air volume; and according to a simulation result under the condition of variable over fire air volume, determining the pulverized coal burn-off rate, the unburned carbon in flue dust, the NOX discharge amount, the lower-hearth outlet temperature and average CO concentration distribution along hearth height of the boiler combustor.

Description

technical field [0001] The invention relates to the field of electric power technology, in particular to a method and device for simulating combustion characteristics of pulverized coal of a power plant boiler under variable burn-off air volume to generate numerical values. Background technique [0002] Pulverized coal combustion in power plant boilers is a complex three-dimensional process of turbulent flow, heat transfer and combustion. Due to the complexity of the process and the variability of coal-fired boiler fuel, so far, there is a lack of mature theory and experience in the design and operation of boilers, and cold and hot tests are often required to determine the operating and design parameters, because the test is intuitive, Reliability and other advantages can be directly used to guide the design, production and manufacture of boiler products. However, at present, my country's thermal power plants have developed towards high parameters and large capacity, and th...

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Problems solved by technology

In this embodiment, the preset boiler burner model is partitioned and meshed; the basic conservation equation, turbulent flow model, turbulent gas-solid two-phase flow model, gas phase turbulent combustion model, pulverized coal particle combustion model, radiation heat transfer Model and NO X The generated model simulates the combustion process of boiler pulverized coal in the pre-set boiler burner model after grid division under the condition of variable overburning air volume; according to the simulation results under the condition of variable overburning air volume, the pulverized coal of the boiler burner is determined Burnout rate, fly ash carbon content, NO X Emissions, outlet temperature of the lower furnace and average CO concentration distribution along the height of the furnace solve the current problem that it is impractical to manufacture a full-scale model test bench due to the increasing size of the furnace, resulting in the inability to control the combustion and flow in the furnace. , The technical problem of measuring the overall regularity of heat transfer

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