基于最优控制极小值原理的加热炉控制

以微型加热炉为被控对象,以工控机IPC、51系列单片机调节仪为硬件,以Kingview组态王、KingACT软PLC、单片机汇编语言为软件,应用最优控制极小值原理的算法进行控制.本应用不仅具体构建了一个实用的二级分布控制系统,还为覆盖大部分典型工业应用的控制系统和系统集成提供了廉价通用的实验实训平台.文中介绍了系统组成、对象数学模型的建立、采用飞升曲线法在线测试对象特性参数、最优控制算法的建立以及具体算法的实现.     

Multifunctional Shape Memory Composites for Joule Heating,Self-Healing,and Highly Efficient Microwave Absorption

Traditional microwaves absorption materials (MAMs) are applied in the form of coatings, generally inflexible, with high production costs and poor adaptability to applications in different locations. The diversification of application scenarios requires materials with multifunctionalities, but it is extremely challenging to integrate multifunctionalities within single material at present. Herein, a multifunctional CoNC@GN/PCL/TPU MAMs is synthesized. The CoNC@GN nano-micro absorber has high-efficiency microwave absorption ability. The electromagnetic microwave absorption performance is ultra-light (4 wt.%), ultra-thin (2.3 mm), and broadband (6.21 GHz), which is better than similar MAMs. Additionally, the samples have highly efficient electro-thermal conversion properties, enabling controlled electrical heating performance and excellent self-healing properties. More remarkably, the sample has an electrically driven shape memory effect that allows the material to target the absorption of multi-angle incident electromagnetic waves. Therefore, CoNC@GN/PCL/TPU absorbers are the key to truly opening up opportunities for flexible, shape memory, and multifunctional absorbers in frontier applications such as wearables, deformable robots, and chip protection.     

基于PLC的电热锅炉温度控制系统设计

利用可编程控制器(PLC)技术对锅炉工作过程进行自动控制,其优点在于:首先提高了燃料的燃烧效率;其次提高了锅炉控制过程的自动化处理程度;另外,良好的人机监控界面使操作人员在监控计算机上能根据控制效果及时地修改运行参数,从而提高了生产过程的实时性、安全性。     

气动加热对空空导弹内部电路的温度影响分析

空空导弹弹体尾部组件所处位置特殊,工作环境严酷,本文基于Flo THERM建立该组件的热仿真模型并进行计算分析,以明确气动加热对弹体内部电路的温度影响程度,为保证元器件留有足够的温升余量提供数据支撑。结果表明,受试产品内部电路的温升相对滞后,而壳体温度峰值时间为内部电路温升迅速变化的分界点,且随自主飞时间的延长温升越为显著。     

金属微波熔炼技术研究与应用进展

微波技术作为一种清洁环保的加热方式,在金属熔炼领域具有潜在的工程应用价值。与传统的熔炼方式相比,微波熔炼技术具有高效节能的特点,可以很好地减轻材料和能源浪费、降低安全风险。文章简要介绍了微波加热技术的发展,讨论了金属微波熔炼的技术原理、工艺特点、装置设计等,在此基础上对微波熔炼目前存在的技术问题及未来发展趋势进行分析。近几年美国的微波熔炼技术发展迅速,已在金属材料制备和零件生产中得到了较为成熟的工业化应用,但国内在该方向上的研究还处于起步阶段,因此完善技术认知、解决瓶颈问题对缩小国 内外该领域的差距、为我国储备新的制造技术具有重要意义。     

气动热环境下高速飞行器光学头罩光传输分析

气动热环境下,光学头罩由于受到气动热和热应力的作用,产生形变且其光学性质发生改变,进而影响到光学头罩内红外辐射光线的传输,使得头罩光学系统成像质量下降,最终将影响高速飞行器的制导精度。以红外成像在高速飞行器上的应用需求为背景,对头罩内光传输进行了数值仿真,得到了头罩光学系统在气动热环境中各项光学评价函数。     

二维圆柱在高超声速气流中的耦合传热计算

高超声速飞行器热结构和热防护设计离不开对飞行器表面的气动热载荷和固体内温度的准确预测,两者之间的耦合作用对此有着重要影响.开展高超声速流场与结构温度场的耦合数值计算,流场部分求解了二维非定常全N-S方程,空间差分采用Harten-Yee的TVD格式,时间离散采用双时间步推进.固体结构传热部分求解了二维非稳态的热传导方程.通过流固交界面,流体从固体部分得到温度边界条件,固体从流体部分得到热流边界条件,从而实现流场和固体温度场的紧耦合计算.将这套算法成功应用于绕无限长圆柱的气动加热计算中,对圆柱在气动加热过程中的温度变化做了详细的分析.     

Photothermal Heating-Assisted Superior Antibacterial and Antibiofilm Activity of High-Entropy-Alloy Nanoparticles

Antibacterial elements and non-contact heating abilities have been proven effective for antibacterial and antibiofilm activities, but it remains a challenge to integrate both within one material. Herein, assisted by the high-entropy effect, FeNiTiCrMnCu_x high-entropy alloy nanoparticles (HEA-NPs) with excellent photothermal heating properties for boosting antibacterial and antibiofilm performances are synthesized. Benefitting from the synergetic effect of copper ions released and thermal damage by the HEA-NPs, more reactive oxygen species (ROS) are generated, leading to the rupture of the cell membranes and the eradication of the biofilms. As a result, the antibiofilm efficiency (400 µg mL⁻¹) of the mostly optimized FeNiTiCrMnCu_1.0 HEA-NPs in the marine nutrient medium, which is the worst-case scenario for the antimicrobial material, can be improved from 81% to 97.4% under 30 min solar irradiation (1 sun). The present study demonstrates a new strategy for effectively treating marine microorganisms that cause biofouling and microbial corrosion using HEA-NPs with photothermal heating characteristics as an antibacterial auxiliary.     

基于气动热约束的高超声速电缆罩封头外形优化设计

基于N-S方程数值计算方法对高超声速气流中导弹电缆罩封头和其后方的电缆罩外形进行气动热计算,对2种封头外形的气动热进行对比分析,研究了其流动机理和流场结构。结果表明:优化后的与后方电缆罩等宽、等高的封头外形极大地降低了电缆罩的热环境。     

红外加热节能技术的现状与发展前景

本文综述了国内外节能的现状与发展趋势,论述了远红外电加热领域的发展前景,强调了加强基础理论研究的重要性,介绍了我国红外加热应用的领域和国外新开发的红外产品。