危废焚烧灰渣等离子熔融系统的热力学分析

Thermodynamic Analysis of Plasma Vitrification of Ash From Hazardous Waste Incinerator

等离子熔融是目前固体废物最有效的处置技术之一,国内外对其进行了大量的研究。本文基于吉布斯自由能最小化原理和质量、能量守恒方程,对危废焚烧灰渣等离子熔融系统进行了热力学分析。研究结果表明,温度和过量空气系数对灰渣熔融的气相产物、固相产物及整个体系的能量平衡有重要影响。温度越高,气相产物主要是CO和H_2;固相产物主要是Fe和SiC;产物的化学能和显热越大,所需要输入的功率也越大。过量空气系数越大,气相产物主要是CO_2和H_2O;固相产物主要是Fe_2O_3和SiO_2;产物的化学能越小,显热越大,所需要输入的功率先减小、后增大。本文建立了一套完善的等离子熔融系统热力学分析模型,为灰渣等离子熔融系统的开发和运行提供了重要的理论指导。

Plasma vitrification is one of the most effective methods in solid waste disposal.Researches on plasma vitrification have been carried out either domestically or abroad.Based on minimization of Gibbs free energy,mass conservation equation,and energy conservation equation,thermodynamic analysis of plasma vitrification of ash from hazardous waste incinerator is carried out.The results show that temperature and excess air ratio of the furnace have an important effect on the gaseous product,solid product and energy balance of the whole system.When the temperature is higher,the main gaseous products are CO and H2;the solid products are mainly Fe and SiC;the chemical energy and sensible heat of the product are larger,and more net input is required.When the excess air ratio is higher,the main gaseous products are CO2 and H2\O;the solid products are mainly Fe2O3 and SiO2;the chemical energy of the product is smaller and the sensible heat is larger,the net input required decreases first and then increases.In this paper,a complete set of thermodynamic analysis model of plasma vitrification is established,which provides an important theoretical basis for the development and operation of plasma vitrification system for the ash from hazardous waste incinerator.