高浓度煤粉燃烧低NOx排放特性的试验研究

为了探讨高浓度煤粉燃烧对NOx排放特性影响的内在机理，在一维火焰炉试验台上，对3种典型煤在不同煤粉浓度燃烧下的NOx前驱物HCN与NH3在主燃区进行了测试，对气相催化还原剂CO及沿炉膛轴向的NOx释放特性进行了分析。试验结果表明：与常规浓度相比，高浓度煤粉燃烧条件下的NOx排放量最大可降低2.2倍。对于不同煤种，最大限度抑制NOx排放的最佳煤粉浓度控制在过量空气系数0.7左右，煤粉燃烧过程中的NOx主要在着火区距炉膛入口0.2~0.4m处产生。在高煤粉浓度下，燃料氮向HCN与NH3的转化率均远远低于常规浓度，同时燃烧过程中产生的大量CO对NOx还原分解的加速是高浓度煤粉燃烧低NOx排放的关键所在。     

基于改进微粒群算法重建炉膛截面温度场

煤粉锅炉炉膛火焰温度场的测量是燃烧调整的基础，对于锅炉燃烧经济性、安全性诊断以及优化运行有着重要的意义。文中利用4个面阵CCD镜头来获取火焰图像的数字信号，在分析测试系统物理模型和炉膛火焰温度分布规律的基础上，建立了非线性优化数学模型，并对其利用基于向量评估的改进微粒群算法进行了求解。为验证测试模型的正确性，进行了数值模拟，并且，在某电站350MW锅炉上进行了多负荷工况下的实际测试。结果表明，重建的温度场可以作为燃烧诊断和优化运行的重要依据。     

PP镁盐晶须复合材料阻燃性能的研究

通过对制备的PP镁盐晶须复合材料的力学性能、燃烧性能、热力学性能测试和SEM分析，研究了十溴联苯醚、三氧化二锑、镁盐晶须用量对复合体系的影响．实验结果表明：镁盐晶须的加入提高了复合材料的力学性能；镁盐晶须与十溴联苯醚之间存在协效阻燃作用，提高了复合材料的氧指数；当m（PP）：m（镁盐晶须）：m（十溴联苯醚）为100：20：15时，协同阻燃效果最佳．     

Preparation and characterization of collagencoclotriphosphazene and its action in flame-retardant viscose fiber

Abstract

In order to develop a flame retardant using the phosphazene derivative of a natural polymer, hexachlorocyclotriphosphazene and collagen were used as the raw materials to synthesize collagencoclotriphosphazene. The Fourier transform infrared results indicate that flame retardant collagencoclotriphosphazene(CGCP) was successfully synthesized. Thermal properties of CGCP were evaluated using thermogravimetry. The thermal analysis shows that the introduction of phosphazene into collagen lowered the primary decomposition temperature, increased the decomposition rate, and caused less weight loss. The viscose fibers blended by CGCP were prepared by the wet spinning method, and the properties of the fiber were investigated. Limiting oxygen index of the flame-retardant fiber containing 12% CGCP was 28.3%, which increased greatly comparing to the fiber sample without CGCP and just decreased slightly to 27.6% after 30 washing cycles. The thermal analysis shows that the introduction of CGCP increased the decomposition rate of viscose fiber at a lower temperature, and caused less weight loss. After burning, the scanning electron microscopy image showed an inflated carbonized coat on the fiber surface. The effect of CGCP on the mechanical properties of the fibers was insignificant. CGCP was compatible with cellulose, and the flame retardancy of the viscose fiber was significantly improved. Due to the introduction of CGCP, moisture regain of the fiber is a little higher than that of viscose fiber.     

环状磷腈/聚磷酸铵/三聚氰胺膨胀阻燃环氧树脂研究

本文以DOPO衍生物六(4-DOPO羟甲基苯氧基)环三磷腈(DOPOMPC)、聚磷酸铵(APP)以及三聚氰胺(MEL)形成复配膨胀体系(IFR)阻燃环氧树脂.采用极限氧指数(LOI)、水平、垂直燃烧(UL-94)方法研究了IFR体系对环氧树脂体系阻燃性能影响,通过锥形量热(CONE)研究了体系燃烧特性,通过扫描电子显微镜(SEM)对体系成炭情况进行观察.结果表明,IFR膨胀阻燃体系对环氧树脂具有良好的协同阻燃作用,其中8%DOPOMPC/8%APP/4%MEL(EP3)体系LOI值较纯EP(EP0)提高37.8%;各项燃烧参数也得到了改善,热释放速率峰值(pk-HRR)、有效燃烧热平均值(av-EHC)、比消光面积平均值(av-SEA)及一氧化碳释放速率平均值(av-CO)相对于10%DOPOMPC/10%APP/EP(EP1)分别降低了53.8%、84.4%、57.7%和75.8%;拉伸强度、弯曲强度和冲击强度较EP1分别提高了1.3倍、79.4%和2.5倍;宏观拍摄和扫描电镜结果表明EP3膨胀炭层连续、均匀、致密,阻燃效果良好.     

基于视频图像的远程火灾探测系统

将传感器技术用于大空间火灾探测时,存在距离短、误报率高、可靠性差等不足。为此,在TMS320DM642微处理器和TI的DSP/BIOS实时操作系统上,设计基于视频图像的远程火灾探测系统。建立RGB空间颜色模型,对连续数帧火灾图像做预处理,分析频闪特性并进行模糊聚类,提取疑似目标区域,以火焰相关性、面积变化率和圆形度3个特征作为火灾识别依据。实验结果表明,该系统提高了大空间图像型火灾探测的精度和速度,可满足远程火情监测需要。     

Numerical characterization of a premixed flame based annular microcombustor

Thermal inertia of the surrounding hardware or elaborate flow arrangement is used for external recirculation of heat in many microcombustors, increasing the weight and pressure losses. Recent research promotes hydrogen as a promising fuel for microcombustion due to its high heat of combustion. On this background, a hydrogen-fuelled microcombustor of simple construction was designed, which utilized the external thermal recirculation by a hollow nitrogen-filled tube inserted in the flame. The present paper reports stabilization and structure of a well stabilized stoichiometric H₂-air flame established in this microcombustor with the help of a detailed computational fluid dynamics model. Self-sustaining combustion could be achieved without any need for catalytic action. An asymmetric flame composed of two branches was stabilized on the walls at a location where the wall heat losses were balanced by the wall heat conduction. The flame thickness exceeded its characteristic one-dimensional value and flame zone broadened from the base to the tip due to heat losses and differential diffusion of hydrogen. Finally, the performance data for different inlet mass flow rates and wall thermal conductivities revealed useful operating points of the microcombustor for applications including micro-propulsion, heating and portable electric power generation.     

钢质管道表面火焰熔覆玻璃涂层

研究了在钢质管道表面采用氧气－石油天然气火焰熔覆玻璃涂层的工艺。试验表明，选择合适的预热温度，送粉量，保护及密着剂可以获得均匀，无裂纹，密着性良好的耐蚀喷瓷管道。．     

深基坑工程水压力计算及止水帷幕设计

深基坑支护工程中对于水的处理是非常关键的一个技术问题。对深基坑设计时水压力的计算和基坑降排水、止水设计等问题进行了讨论 ,并提出了水压力修正系数 (Kw)的经验公式 ,介绍了壁后注浆法、桩间摆喷止水帷幕法等止水措施。