Austenite Recrystallization and Controlled Rolling of Low Carbon Steels

The dynamic recrystallization and static recrystallization in a low carbon steel were investigated through single-pass and double-pass experiments. The results indicate that as the deformation temperature increases and the strain rate decreases, the shape of the stress-strain curve is changed from dynamic recovery shape to dynamic recrystallization shape. The austenite could not recrystallize within a few seconds after deformation at temperature below 900 ℃. According to the change in microstructure during deformation, the controlled rolling of low carbon steel can be divided into four stages： dynamic recrystallization, dynamic recovery, strain-induced ferrite transformation, and rolling in two-phase region. According to the microstructure after deformation, the controlled rolling of low carbon steel can be divided into five regions： non-recrystallized austenite, partly-recrystallized austenite, fully-recrystallized austenite, austenite to ferrite transformation, and dual phase.

Controlled Rolling and Cooling Process for Low Carbon Cold Forging Steel

Effect of controlled rolling and cooling process on the mechanical properties of low carbon cold forging steel was investigated for different processing parameters of a laboratory hot rolling mill. The results show that the specimens with fast cooling after hot rolling exhibit very good mechanical properties, and the improvement of the mechanical properties can be attributed mainly to the ferrite-grain refinement. The mechanical properties increase with decreasing final cooling temperature within the range from 670 ℃ to 570 ℃ due to the finer interlamellar spacing of pearlite colony. The specimen with fast cooling after low temperature rolling shows the highest values of the mechanical properties. The effect of the ferrite grain size on the mechanical properties was greater than that of pearlite morphology in the present study. The mechanical properties of specimens by controlled rolling and cooling process without thermal treatment were greatly superior to that of the same specimens by the conventional rolling, and their tensile strength reached 490 MPa grade even in the case of low temperature rolling without controlled rolling. It might be expected to realize the substitution medium-carbon by low-carbon for 490 MPa grade cold forging steel with controlled rolling and cooling process.

Effect of zirconium addition on the austenite grain coarsening behavior and mechanical properties of 900 MPa low carbon bainite steel

The ultra-fine bainitic microstructure of a 900 MPa low carbon bainitic Cu-Ni-Mo-B steel was obtained by a newly developed relaxation precipitation control （RPC） phase transformation processing. In a pan-cake like prior-austenite grain, the micro- structure consisted of lath bainite, a little of abnormal granular bainite, and acicular ferrite. The effect of zirconium carbonitrides on the austenite grain coarsening behavior was studied by transmission electron microscopy （TEM）. The results show that, the lath is narrower with increasing cooling rate. The ratio of all kinds of bainitic microstructure is proper with the intermediate cooling rate; and Zr-containing precipitates distribute uniformly, which restrains austenite grain growing in heat-affected welding zone.

Developmental Status Quo and Trends of Low-carbon Agriculture

In order to reduce carbon emission in agricultural production,this paper has discussed the developmental trends of low-carbon agriculture in terms of developing precision agriculture,improving the efficiency of fertilizer utilization,scientific use of pesticides,water-saving irrigation,ecological control of pests and diseases,as well as energy conservation and emission reduction by agricultural machinery and other agricultural practices.

Carbon Emission Modeling and Analysis in Manufacturing Process for Numerical Control Machine Tools

Reducing carbon emissions( CEs) is the urgent demand all over the world. In order to realize the low-carbon numerical control( NC) machining, the evaluation model of a part's manufacturing carbon emission with NC machine tools was built by considering the influences of the cutting tool geometrical parameters.The manufacturing CEs were produced by electric power,cutting tools,and cutting fluid consumed in manufacturing process. The parameters of cutting tools affected not only the CEs,but also the machining quality. Then the actual constraint models of the machine performance,machining quality were given in order to optimize the cutting parameters and achieve the low-CEs. Finally,a case was given to analyze the influences of the cutting tool angles on the manufacturing CEs. The results show that the CEs decrease as the rake angle and edge angle increase under the constraints of the machine specifications and machining quality.

暖通空调技术在室内空气环境品质控制中的应用

文章研究了暖通空调技术在室内空气环境品质控制中的应用,重点分析了新风系统设计、换气效率优化策略、空气净化技术集成以及智能调控系统的实践应用,强调了合理设计新风量、采用变风量控制、实施热回收、选用高效过滤材料、利用活性炭和光触媒技术的重要性。

Modeling of Microstructure Evolution and Mechanical Properties of Steel Plates Produced by Thermo-Mechanical Control Process and Its On-line Application

An integrated metallurgical model was developed to predict microstructure evolution and mechanical properties of low-carbon steel plates produced by TMCP. The metallurgical phenomena occurring during TMCP and mechanical properties were predicted for different process parameters. In the later passes full recrystallization becomes difficult to occur and higher residual strain remains in austenite after rolling. For the reasonable temperature and cooling schedule, yield strength of 30 mm plain carbon steel plate can reach 310 MPa. The first on-line application of prediction and control of microstructure and properties (PCMP) in the medium plate production was achieved. The predictions of the system are in good agreement with measurements.

中国铁矿石选矿技术发展与展望

铁矿石作为钢铁工业最为重要的原材料,是我国重要的战略性矿产资源之一。我国铁矿资源储量丰富,但97%以上属于贫矿,需要经过选矿富集后才能供给高炉炼铁。多年来,在我国选矿工作者的共同努力下,我国铁矿选矿技术得到长足进步和发展。通过回顾我国铁矿选矿技术的发展历程,综述单一弱磁选、单一浮选、重选—磁选—反浮选、磁化焙烧—磁选等主要选矿技术在我国铁矿选矿厂的应用,总结我国典型多金属共生型铁矿石如伴生稀土/萤石型铁矿石、伴生钛铁矿型铁矿石、伴生多金属硫化物型铁矿石和伴生硼铁矿型铁矿石的选矿现状,介绍影响我国铁矿选矿技术进步的关键设备如圆锥破碎机、高压辊磨机、半自磨机、立环脉动高梯度磁选机、高频振动细筛、搅拌磨机等,指出我国铁矿选矿未来要以“高效节能、低碳减排”为原则,以“优质优用、劣质能用”为战略,开发选冶联合工艺,研发大型高效设备,研制低温环保药剂,提高智能控制水平,加强资源综合利用。

双碳背景下城镇供热现状及低碳转型发展建议

在“双碳”政策不断推进和人民生活质量持续攀升背景下,供热行业低碳转型和深化改革已成为迫切需要面对并解决的重大课题。本文以存在的实际问题为研究导向,深入剖析城镇供热领域的发展现状及其面临的主要挑战,提出一系列能够解决困扰政府、企业生存发展问题,促进行业转型升级的措施建议,从而推动城镇供热低碳转型,助力供热行业向安全、高效、节能、低碳、智慧化方向高质量发展。

基于奖惩阶梯型碳价机制的能源枢纽低碳优化策略

为进一步降低碳排放水平以及源-荷不确定性对系统运行的影响,文中提出一种基于奖惩阶梯型碳价机制和分布式模型预测控制(distributed model predictive control,DMPC)的能源枢纽(energy hub,EH)日前-日内-实时多时间尺度低碳优化调度策略。引入奖惩阶梯型碳价计算方法,构建EH日前低碳优化调度模型,并制定基于DMPC的日内滚动和实时调整的反馈闭环优化策略,降低源-荷预测误差,提高传统模型预测控制(model predictive control,MPC)的求解效率。在日内阶段,构建以阶梯型碳成本、运行成本和储能调整惩罚成本之和最小为目标的日内滚动优化模型;在实时阶段,分解整体优化问题,建立基于DMPC的多智能体实时调整模型。算例结果表明,文中所提策略能够有效提升系统经济效益,降低源-荷不确定性,实现EH的低碳经济、稳定可靠运行。

把握双控转向机遇推动首都绿色高质量发展的思考与建议

推动能耗双控转向碳排放双控是党中央立足国家发展实际,促进经济社会全面绿色低碳转型作出的重大制度设计。本文结合北京市“五子”联动所面临的绿色发展新形势,深入分析了双控转向制度内涵以及与北京市重点工作的绿色联动效应,提出开展低碳技术攻关、激发自愿减排市场活力、推动算力中心绿色升级、发展绿色低碳供应链、构建京津冀区域清洁低碳能源体系等方面的措施建议,推动形成碳达峰碳中和的北京实践,为首都高质量发展提供有力支撑。

光伏离网供电空调控温储粮技术应用

光伏离网供电空调控温储粮系统由光伏发电板、智能控制器、光伏空调和能源管理系统组成。智能控制器通过智能补偿、智能控制算法,实现光伏和市电双电源无缝切换,优先使用光伏,实现光伏零浪费,光伏直驱空调直接利用光伏板发的直流电来驱动机组,达到节能降耗的目的。解决了制冷空调用电费用高、光伏发电投资成本高和投资回收期长的问题。显著降低了空调控温的运行成本,实现了储粮空调控温的“零”碳或低碳的绿色储粮技术。

低碳铝镇静钢精炼渣理化性能研究及动态调控

为提升低碳铝镇静钢水的可浇性,基于低碳铝镇静钢精炼渣的热力学计算,研究典型组分CaO/Al2O3(C/A)、SiO_(2)、FeO对精炼渣液相线温度、1650℃黏度和表面张力的影响规律,结合精炼渣理化性能(熔点和黏度-温度曲线)测试结果,建立吹氩直上精炼渣动态调控模型,并投入生产实践应用。结果表明:随着C/A增加,精炼渣熔点在渣中SiO_(2)质量分数为5%时单调升高,在渣中SiO_(2)质量分数为10%时先降后升,另随C/A的增加精炼渣黏度及黏度-温度曲线的转折温度升高;精炼渣组分范围为C/A 0.75~1.50、SiO_(2)质量分数0~10%、FeO质量分数2%~6%时,可获得较低的液相线温度、较高的黏度和表面张力。生产实践中应用建立的模型可实现造渣物料的动态加入,精炼渣理化性能的稳定性得到显著提升,精炼渣的C/A和全铁(TFe)质量分数标准差明显降低;液相线温度、1650℃时的黏度和表面张力平均值分别降低6.9℃、增加0.0206 Pa·s和0.0109 N/m;全氧(TO)质量分数均值由2.78×10(-3)%下降为2.25×10(-3)%,改进了19.1%,钢水的可浇性得到显著改善。

2022中国可再生能源绿色电力证书发展现状与展望

绿证是市场化方式驱动可再生能源高质量发展的重要举措,对推动能源绿色低碳转型意义重大。为此,梳理了国内外绿证发展历程,系统回顾了我国绿证政策的历史沿革;基于详实的数据,分析了我国绿证核发交易情况;结合最新政策,剖析了绿证机制的新变化;最后从引导绿电消费、支撑能耗双控、衔接碳市场、提升国际影响等方面展望了中国绿证发展趋势。

建筑业钢筋工程质量追溯及成本控制研究——以广西自治区的建筑业钢筋加工为例

国家提出要持续开展绿色建筑创建行动,落实碳达峰碳中和目标任务,加快转变“大量建设、大量消耗、大量排放”的建设方式,推动城乡建设绿色发展。在建筑工业化领域实施智能建造模式是推动实现这一目标的有力举措,使整个工程实际施工实现从传统现场施工到项目的工厂化生产,有助于解决人力资源不足和技术水平参差不齐的痛点,从而有效提高工程建造的效率和控制施工成本。本文以智能建造为切入点,基于钢筋智能化生产加工领域内实际生产成本数据,将数据同步至质量追溯系统,分析当前成本控制效果,为钢筋加工智能化生产领域的成本控制提供降本增效措施建议,为推广成型钢筋应用提供数据支撑,进一步推动智能建造与建筑工业化协同发展。

基于作物安全性的农业温室综合能源系统低碳控制方法

农业温室综合能源系统(agricultural greenhouse integrated energy system,AGIES)需深入考虑作物安全生长环境条件,优化调控多源设备功率,实现系统经济、低碳运行。提出了一种基于作物安全性的AGIES低碳控制方法,构建含电、气、热AGIES供能架构,建立各农业设备功率模型,阐明能量流和功率耦合设备的能量转换机制。研究农作物生长的光照、温度、供水安全边界条件,提出作物的日光照量与小时光照量合理范围、室内恒温供热功率范围、科学供水用电功率范围与用电时间范围,并采用数学模型详细描述。提出了电、气、热碳排放核算指标,建立综合运行成本和碳排放成本最低的功率优化控制模型,采用粒子群算法求解,得到优化用能方案。通过算例仿真验证了所提方法的可行性和有效性。

基于降本增效目标的污水处理厂低碳运行调控策略

研究了低成本、高处理要求下污水处理厂的低碳运行调控策略,以南方某污水处理厂为例,分析了影响除磷效率原因,发现主要的影响因素包括污泥龄、污泥浓度、溶解氧、回流比、药剂投加位置等,并根据不同季节的进水特征,制定了优化的运行参数,如污泥浓度、气水比、溶解氧水平等。通过实施低碳运行调控策略,该厂的出水水质仍可达到排放要求,且呈现稳中有降的趋势,同时,除磷药耗减少了约41%,吨水电耗下降了26.5%,碳排放间接减排0.18 kg/t(以CO_(2,eq)计),同步实现了节能降耗与清洁生产的目标。

碳普惠制对包容性低碳增长的影响研究

论文以2010—2021年中国270个城市作为数据样本,以广东省碳普惠制试点城市作为主要研究对象。首先,围绕“经济—社会—低碳”三个维度构建了指标体系,从效率视角对中国城市包容性低碳增长水平进行了测度;其次,运用合成控制法验证了碳普惠制对包容性低碳增长效率的影响;最后,剖析了碳普惠制对包容性低碳增长的作用机理。研究发现:(1)碳普惠制显著提升了地区包容性低碳增长水平。(2)碳普惠制对包容性低碳增长效率中技术进步和技术效率的促进作用存在异质性特征。(3)碳普惠制可以在不影响地区经济增长的情况下,显著提升社会包容与低碳发展水平。(4)碳普惠制能够通过促进绿色技术创新,增强公众环境关注,提升数字经济水平三条路径促进包容性低碳增长。研究结果可为政府对碳普惠制的评估与推广提供一定的决策依据。

基于S7-200PLC、MCGS的教室灯光智能控制系统设计与仿真运行

基于高校基础建设快速发展,老旧教室灯光控制由传统手工方式向基于S7-200PLC、MCGS的灯光智能控制系统转变。本文对教室照明光强度、传感器分布、PLC程序设计、灯光控制问题等进行设计及仿真运行。结果表明,灯光智能控制系统有效降低了电能损耗,提高了灯光照明效率,同时也满足了学院低碳运行、绿色发展的现实需要。

涂装车间智能烤箱控制系统的应用

主要介绍了北京奔驰涂装车间智能烤箱控制系统的基本原理、应用及控制思路。通过分析阐述烤箱系统的结构、原理及工艺参数等信息,研究出一套完整的节能优化方案。