硅钙合金矿热炉烟气余热分析与利用研究

发布时间：2018-10-24 08:27

【摘要】：大部分铁合金产品采用电热法生产,对电能的需求量较大,属于高能耗,高物耗产业,是国家十三五规划中的重点节能减排行业。近年来,市场对铁合金产品的需求不断增大,同时由于能源紧迫,原材料价格居高不下,环境污染问题日益严峻,同时国家也进一步加大了相关节能减排政策力度,使矿热炉节能减排问题日益凸显。本文从硅钙矿热炉烟气余热出发,对烟气余热进行分析和利用研究具有十分重要的现实意义和广泛的应用前景。本文对3台3MW硅钙矿热炉烟气温度、流量、成分进行了测试分析,研究得出烟气温度、流量呈不规则周期性波动,生产冶炼制度对温度、流量的影响较大。本文利用热力学第一、第二定律、焓值分析法和（火用）值分析法对烟气余热的数量和质量进行分析研究;并且通过对烟气余热的“总能系统”和“能级平衡”分析,提出采用能级系数作为评估余热资源的全利用指标并指导余热回收方案的选择。全文通过研究得出如下结论:(1)通过测试得到烟气温度以及流量随生产过程的变化关系。在出硅钙合金时,烟气温降有时高达150℃,并且呈现周期性变化,因而在余热回收过程时,要考虑余热资源供给的变化。(2)结合热力学第一定律和第二定律,采用焓值分析法、（火用）值分析方法,对余热资源数量和质量进行分析。通过计算得到生产过程中矿热炉高温烟气可回收的热能值为32378.23MJ/h,烟气可回收（火用）值为20122.99MJ/h,根据能量平衡分析得出全年高温烟气带走的热量为85.09×107MJ占所有支出能量的43.02%,余热资源回收潜力大。(3)基于烟气余热的“总能系统”和“能级平衡”概念,通过能级系数来考察余热资源的全利用品质的指标,得出余热资源适合生产温度为320℃、压强为1.27MPa的蒸汽。但硅钙矿热炉在生产过程中对电能的需求是主体,所以经济且合理的余热利用方式是用来发电。此外,对单独余热发电以及热电联产的热能利用系数与节能状况进行比对分析,发现热电联产热能利用率提高了20%,每年可节约的电能增加了1.42×107KWh。同时还探讨了影响余热回收和利用的主要影响因素,并对热电联产系统的经济性、节能减排进行分析,得出是一个典型的余热资源综合利用方案,取得了良好的经济效益和社会效益。
[Abstract]:The majority of ferroalloy products are produced by electrothermal method, which has a large demand for electric energy, which belongs to the industry of high energy consumption and high material consumption, and is the key industry of energy saving and emission reduction in the 13th Five-Year Plan of China. In recent years, the market demand for ferroalloy products has been increasing. At the same time, due to the urgency of energy, the high prices of raw materials and the increasingly serious environmental pollution problems, the state has also further strengthened the relevant energy saving and emission reduction policies. The problem of energy saving and emission reduction is becoming more and more prominent. In this paper, the analysis and utilization of the waste heat of flue gas from a calcium silicate furnace has very important practical significance and wide application prospect. In this paper, the flue gas temperature, flow rate and composition of three 3MW silica calcareous furnace are tested and analyzed. The results show that the flue gas temperature and flow rate fluctuate irregularly, and the production and smelting system have a great influence on the temperature and flow rate. In this paper, the first and second laws of thermodynamics, enthalpy analysis and exergy value analysis are used to analyze the quantity and quality of flue gas residual heat, and the total energy system and energy level equilibrium of flue gas residual heat are analyzed. The energy level coefficient is used to evaluate the total utilization of waste heat resources and to guide the selection of waste heat recovery schemes. The main conclusions are as follows: (1) the variation of flue gas temperature and flux with production process is obtained by testing. In the case of silica calcium alloy, the temperature drop of smoke sometimes reaches 150 鈩，

本文编号：2290862