热态实时测量灰渣生长率、导热系数和流动性以研究结渣机理

Ash-related slagging and fouling during combustion process is a classic problem which plague the safe and economic operation of the boiler. In recent years, with the application of high sodium coal, coal /biomass blending and gradual promotion of the oxy-fuel combustion, the mechanism research of fouling and slagging is increasingly drawing attention. The conventional slagging-related research usually apply the slagging bars weighing method, which cann't obtain the curves of slagging thickness online. Subsequently, slagging smaples are slowly cooled and analyzed the phenomenon of recrystallization or vitrification. This will give rise to without acquisition of the thermal conductivity of each layer for the slag. The project intends to develop a novel online monitoring method which can measure the slagging growth rate, heat flux, the surface temperature of ash deposits, and calculate the thermal conductivity of each layer for the ash deposits. Meanwhile, combined with the method of liquid nitrogen quenched slag samples, the high temperature slag layer can be rapidly cooled and then supposed to mineral analysis. And investigate of the mechanism of the condensation process of alkali metals for the slagging initial layer, its formation and shedding mechanism, and obtain the thermal conductivity of each layer of ash deposit, the flow characteristic of molten slag.The CFD modelling slagging simulation based on Discrete Element Method will be also conducted. We attempt to gain further insight into the high-sodium coal, coal/biomass blending and the formation mechanism of slagging and fouling under different atmosphere and the corresponding heat transfer characteristics.

燃烧过程中的结渣积灰问题是困扰锅炉安全经济运行的一个传统经典问题，近年来随着新疆准东高钠煤的应用、煤/生物质掺烧和富氧燃烧的逐步推广，结渣积灰的机理研究日益引起重视。常规的结渣研究通常采用结渣棒称重的方法研究，存在不能实时获得结渣厚度曲线、渣样缓慢冷却后分析渣样重结晶或玻璃化导致不能实时获得各层渣的导热特性等问题。本项目拟研究一种新型能热态条件下测量渣层生长速度、热流密度、灰渣表面温度并推算获得各层渣的导热系数的新型结渣积灰在线监测方法，并结合液氮淬冷渣样方法实现高温渣层的急冷随后进行渣层物质分析，研究结渣原生层碱金属凝结过程的机理和原生层的生长机理和后续层的增长和脱落规律，并在线获得灰渣各层的导热系数、熔融灰渣的流动性等表征参数，并开展基于离散单元法的数值模拟结渣过程。对高钠煤、煤生物掺烧以及不同气氛下的结渣积灰生长规律和传热特性进行深入的研究。

燃烧过程中的结渣积灰问题是困扰锅炉安全经济运行的一个传统经典问题，近年来随着新疆准东高钠煤的应用、煤/生物质掺烧和富氧燃烧的逐步推广，结渣积灰的机理研究日益引起重视。常规的结渣研究通常采用结渣棒称重的方法研究，存在不能实时获得结渣厚度曲线、渣样缓慢冷却后分析渣样重结晶或玻璃化导致不能实时获得各层渣的导热特性等问题。本项目拟研究一种新型能热态条件下测量渣层生长速度、热流密度、灰渣表面温度并推算获得各层渣的导热系数的新型结渣积灰在线监测方法，并结合液氮淬冷渣样方法实现高温渣层的急冷随后进行渣层物质分析，研究结渣原生层碱金属凝结过程的机理和原生层的生长机理和后续层的增长和脱落规律，并在线获得灰渣各层的导热系数、熔融灰渣的流动性等表征参数，并开展基于离散单元法的数值模拟结渣过程。对高钠煤、煤生物掺烧以及不同气氛下的结渣积灰生长规律和传热特性进行深入的研究。