城市景观格局对热环境影响遥感研究

为揭示城市景观格局对热环境的影响,在遥感及景观理论的支持下,对长春市1993年、2005年的城市热环境与景观格局进行分析。研究发现,在清理围墙院落等科学、合理的城市规划影响下,研究区"封闭式"的景观状态得以改变,向着离散、多样、均匀的方向发展;热环境也有所改善,特别是高温区面积减少了6.2%;城市热环境不仅与下垫面的景观类型密切联系,还与景观类型的空间组合格局有关系。对该区地表温度与景观多样性指数进行分析,发现二者具有明显的二次抛物线相关关系。     

碳氢燃料泄漏火灾火焰热辐射强度估算

介绍了一种关于碳氢燃料泄漏火灾火焰热辐射强度的估算方法,并运用具体实例进行了验证。同时,还提出了一定强度的火焰热辐射造成对人伤害所需时间的计算方法。     

火电厂脱硫技术综述

介绍火电厂的脱硫技术,对几种主要的脱硫工艺进行技术经济比较,为脱硫工艺的选择提出建议。     

含DOPO磷酸酯阻燃改性环氧丙烯酸树脂的制备及热性能研究

将工业上广泛应用的光固化树脂EA作为基体,通过分子设计,利用甲苯二异氰酸酯TDI的双异氰酸酯结构将合成的磷酸酯阻燃剂ODOPM链接到其分子主链上,制备出一组改性的光固化丙烯酸酯预聚物。利用FT-IR,1 H-NMR,31P-NMR对分子结构进行表征;极限氧指数（LOI）和微型量热仪（MCC）的结果表明材料的阻燃性能明显提高,改性后树脂的热释放速率峰值PHRR相对于EA降低了近66%,总热释放量也明显降低;扫描电镜结果显示改性后的树脂固化膜形成的炭层变得更平滑和致密,并且完整无破裂现象;同时对固化膜的热稳定性和热降解过程进行了探讨。分析论证了ODOPM改性修饰后的EA有更高的阻燃性,成炭能力明显增强,形成的致密炭层有效地阻止了热交换,使材料在高温下更稳定。     

生活垃圾焚烧飞灰重金属的受热特性

研究了飞灰重金属在不同煅烧温度下的挥发情况及其存在形态.结果表明:重金属挥发能力由强到弱依次为Hg＞Pb＞As、Cd＞Zn＞Cr、Ni、Cu;其中Hg、Pb、As和Cd属易挥发重金属,在1 150 ℃时几乎全部挥发;Zn属较易挥发重金属,1 150 ℃时的挥发率在40%～50%;Cr、Ni和Cu属难挥发重金属,在1 150 ℃的挥发率不超过10%;在400～1 150 ℃,随温度的升高,部分Zn、Hg、Cu、Pb、Cd、Ni和As由可溶态向残渣态、铁锰氧化态转化;在400～900 ℃,随温度的升高Cr可溶态比例减少,而在900～1 150 ℃,随温度的升高其可溶态比例增加.     

Parametric sensitivity analysis for thermal runaway in semi-batch reactors: Application to cyclohexanone peroxide reactions

The semi-batch reactors (SBRs) system, which is widely used in industrial processes, possesses an intrinsic parametric sensitivity, in which infinitesimal disturbances of input parameters can result in large variations in output variables. In this work, local parametric sensitivity analysis (PSA) was used to understand parameter variations and global PSA was conducted to examine the interaction of input parameters. The effects of these parameters on the output of the system model were analyzed based on the Monte Carlo method with Latin hypercube sampling and the extended Fourier amplitude sensitivity test model. The results showed that the evolution of thermal behaviors in SBRs were observed: marginal ignition; thermal runaway; and the quick onset, fair conversion, and smooth temperature profile. The threshold point of transition from marginal ignition to thermal runaway was at the maximal value of local sensitivity, for which the slope with respect to cooling temperature equaled zero. Moreover, the sequence of the global sensitivity of six common input parameters was computed and evaluated. The reliability of the numerical models was verified by using our previous experimental results of cyclohexanone peroxide reaction. This comprehensive sensitivity analysis could provide valuable operating information to improve chemical process safety.     

熔盐蒸发器管板封口焊缝泄漏原因分析

某光热电站熔盐蒸发器入口侧管板封口焊缝发生泄漏,通过表面检测和观察,发现裂纹是从封口焊缝根部发展,并从根部向外扩展的。根据裂纹扩展方向和运行数据进行综合分析认为,熔盐蒸发器在未正确操作下导致在极短时间内管板下部表面升温过快,造成封口焊缝局部热应力过大。在焊缝残余应力、工作应力和热应力共同作用下,管板下部封口焊缝根部产生裂纹并扩展至焊缝表面,形成贯穿性裂纹,造成蒸发器管板泄漏。     

Peculiar effect of acylamino and cyan groups on thermal behavior of 2-(1-cyano-1-methylethyl)azocarboxamide

2-(1-Cyano-1-methylethyl)azocarboxamide (CABN) is a representative of new-type azo initiator in the radical polymerization industry. The peculiar water and oil soluble characters make it a versatile rising star for the industry to initiate the polymerization of monomers in either polar or nonpolar solvents based continuous phases. This paper decodes the effect of acylamino and cyan groups on thermal stability and hazards of CABN via advanced thermokinetic analysis and numerical simulation. Initially, simultaneous thermogravimetric analyzer was employed to evaluate the thermal stability of CABN and its two structurally similar azo compounds (azos), azobisisobutyronitrile (AIBN) and azodicarbonamide (AC). Followed with calorimetric experiments by differential scanning calorimetry, the effect of two functional groups on thermal behavior parameters, such as decomposition temperature, melting point, and heat of decomposition was estimated. The results indicated that the acylamino group can improve the thermal stability of CABN but with bulkier heat release. Ultimately, through the medium of thermokinetic analysis, the thermal hazard of AIBN, CABN, and AC was simulated based on auto-ignition and thermal explosion theory. The research results would provide references for the synthesis of new-type azo initiators and process safety parameters to the polymerization industry.     

Investigation of an accidental explosion in a nitromethane rectification process

An explosion that occurred during a nitromethane rectification process is investigated. Experiments were performed in an effort to elucidate the cause of the explosion. All test samples analyzed, including reaction product, crude product, 99% pure product and raffinate, were collected from the accident site. Gas chromatography was used to analyze the components of the samples, thermal analysis determined the exothermic character of the samples and the sample evaporating experiment recorded the reaction phenomena occurring at low liquid level. Based on the experimental results, the excess heat released by the decomposition of overheated raffinate is pinpointed as the root cause of the explosion.