鋼鐵流程系統(tǒng)的能耗排放特征及其廣義熱力學(xué)優(yōu)化

陳林根++馮妍卉++姜澤毅++謝志輝++魏曙寰

摘 要：鋼鐵生產(chǎn)流程能源配置技術(shù)落后、集成度低。為在整體上實(shí)現(xiàn)鋼鐵生產(chǎn)流程的節(jié)能減排，該研究圍繞解決對(duì)應(yīng)的關(guān)鍵科學(xué)問題“鋼鐵生產(chǎn)流程物流—能流—環(huán)境作用機(jī)理及其多目標(biāo)集成優(yōu)化理論”，在工序模塊、單體組件和功能子系統(tǒng)層面開展了前期研究，為實(shí)現(xiàn)全流程仿真和優(yōu)化奠定了基礎(chǔ)。主要包括：（1）提出絕熱過程火積耗散極值原理，對(duì)等溫和對(duì)流輻射傳熱邊界條件下6種不同形狀的加熱爐絕熱層進(jìn)行構(gòu)形優(yōu)化，得到整體絕熱性能最優(yōu)的絕熱層構(gòu)形。（2）提出“廣義構(gòu)形優(yōu)化”理論，將火積理論引入板坯連鑄凝固傳熱過程的研究中，分別考慮熱損失率和火積耗散率目標(biāo)，得到同時(shí)兼顧板坯內(nèi)部溫度梯度和表面溫度梯度的二冷區(qū)水量分配最優(yōu)構(gòu)形。（3）運(yùn)用系統(tǒng)動(dòng)力學(xué)原理，構(gòu)建燒結(jié)、煉鐵工序的鐵素流動(dòng)態(tài)模型，獲得不同返回物質(zhì)流情況下的鐵素流整體宏觀動(dòng)態(tài)特性。（4）基于“運(yùn)動(dòng)參考坐標(biāo)系”，建立燒結(jié)礦冷卻過程二維非穩(wěn)態(tài)連續(xù)模型，獲得相應(yīng)的流場(chǎng)、壓力場(chǎng)、溫度場(chǎng)特性。（5）基于非線性規(guī)劃理論建立高爐煉鐵過程優(yōu)化模型，分別以爐腹煤氣量指數(shù)相關(guān)聯(lián)的高爐利用系數(shù)和碳排放為優(yōu)化目標(biāo)，研究爐腹煤氣量指數(shù)等參數(shù)和高爐噴吹煤粉、噴吹塑料對(duì)優(yōu)化結(jié)果的影響。（6）建立中厚鋼板軋后冷卻過程數(shù)學(xué)模型，明晰設(shè)計(jì)參數(shù)和冷卻方式對(duì)鋼板表面和終冷溫度的影響。（7）構(gòu)建以火用為表征參數(shù)的特征化模型，以高爐-轉(zhuǎn)爐煉鋼、電爐煉鋼過程為例，分析鋼鐵生產(chǎn)流程資源和能源交互作用的耦合關(guān)系。（8）建立鋼鐵生產(chǎn)流程分析模型，計(jì)算典型鋼鐵企業(yè)碳、氮、硫等元素向多形態(tài)廢棄物轉(zhuǎn)換及排放的數(shù)量和結(jié)構(gòu)。計(jì)算鋼鐵生產(chǎn)過程的環(huán)境負(fù)荷數(shù)據(jù)，得到我國(guó)典型鋼鐵生產(chǎn)過程資源、能源消耗和CO2、SO2、NOx、CO、CH4等排放清單。（9）運(yùn)用各層次單元之間的物流、能流關(guān)系及流程網(wǎng)絡(luò)重構(gòu)技術(shù)，開發(fā)工序能質(zhì)平衡計(jì)算與流程仿真軟件。（10）構(gòu)建具體到工序?qū)哟蔚匿撹F生產(chǎn)、加工和消費(fèi)的全生命周期物質(zhì)流模型，分析不同情景下中國(guó)廢鋼增長(zhǎng)趨勢(shì)對(duì)鋼鐵流程的結(jié)構(gòu)演變及其能耗和排放的影響。（11）研究鑄軋區(qū)段生產(chǎn)組織及鋼坯熱送熱裝等流程節(jié)能技術(shù)，提出節(jié)能技術(shù)優(yōu)化組合概念，探討關(guān)鍵技術(shù)之間的關(guān)聯(lián)關(guān)系和優(yōu)化組合模式。（12）建立12種鋼廠余能余熱驅(qū)動(dòng)簡(jiǎn)單和復(fù)雜、閉式和開式燃?xì)廨啓C(jī)動(dòng)力裝置、熱電聯(lián)產(chǎn)裝置和熱電冷聯(lián)產(chǎn)裝置的經(jīng)典熱力學(xué)和有限時(shí)間熱力學(xué)模型并進(jìn)行性能分析和優(yōu)化；建立兩種鋼廠低溫余熱驅(qū)動(dòng)半導(dǎo)體熱電發(fā)電機(jī)模型并進(jìn)行數(shù)值模擬。明晰各系統(tǒng)的熱力學(xué)整體特性及基本優(yōu)化關(guān)系，獲得各個(gè)工序余能余熱驅(qū)動(dòng)熱力過程和循環(huán)的最佳設(shè)計(jì)方案。

關(guān)鍵詞：鋼鐵生產(chǎn)流程 物質(zhì)流 能量流 節(jié)能減排 計(jì)算機(jī)仿真 整體特性 廣義熱力學(xué)優(yōu)化

Energy Consumption， Emission Characteristics and Generalized Thermodynamic Optimization of Iron & Steel Process Systems

Chen Lingen1 Feng Yanhui2 Jiang Zeyi2 Xie Zhihui1 Wei Shuhuan1

（1.Naval University of Engineering，PLA； 2.University of Science & Technology Beijing，USTB）

Abstract：In order to achieve the overall objective of energy conservation and emission reduction of iron and steel production process， this subject focused on the key scientific problem of “the action mechanism among material flow， energy flow and environment and the corresponding multi-objective integration optimization theory in iron and steel production process” and performed preliminary study as follows： （1）The entransy dissipation extremum principle for thermal insulation process is proposed and applied into the constructal optimizations for insulation layers of reheating furnace wall. （2）The theory of generalized constructal optimization is proposed and applied to search the optimal water flow distributions of secondary cooling zone for slab continuous casting. （3）The system dynamic models for iron-flow of sintering and ironmaking are established and the overall macroscopic dynamic characteristics of iron-flow are obtained. （4）The gas flow， pressure and temperature fields of the sinter ore cooling process are obtained based on a 2D transient consecutive model. （5）The optimizations of blast furnace ironmaking process are performed with blast furnace utilization coefficient and carbon emission as objectives. （6）The effects of design parameters and cooling methods on surface temperature and final cooling temperature are analyzed for cooling process after plate rolling. （7）The coupling relationship of the interaction between the resources and energy of iron and steel production process is analyzed based on an exergy characterized model. （8）The quantity and structure of the conversion and emissions to polymorphic waste of carbon， nitrogen， sulfur and other elements in typical companies are calculated based on the analysis model for iron and steel production process. （9）The software package for energy and material balance and process simulation are developed. （10）The effects of the growth trends of steel scrap on routes evolution， energy consumption and emissions of the production process are analyzed based on the material flow model for entire iron and steel life-cycle. （11）The concept of optimal combination of energy-saving technologies is proposed and the correlation and optimal combination mode among key technologies are discussed. （12）The performance analyses and optimizations for 14 classical and finite time thermodynamic models of energy conversion processes and cycles driven by residual energy in iron and steel plants have been performed.

Key Words：Iron and steel production process； Material flow； Energy flow； Energy conservation and emission reduction； Computer simulation； Golable characteristics； Generalized thermodynamics optimization