中国地区人为热分布特征研究

利用中国统计年鉴中全国各省份的非再生能源消费资料和2.5min×2.5min分辨率的人口格点数据,对中国地区人为热排放的时空分布进行研究,讨论了其分布特征和影响因素.结果表明,中国地区人为热通量随时间持续增长,特别是在2000年后增长加速,1985年到2000年从0.09W/m2增长到0.16W/m2,而到2013年已经增长到0.38W/m2.中国地区的人为热排放具有显著的地域特征,在华北、华东和华南,由于人口密度大、经济发达,人为热的污染很严重;在华中地区,人为热污染较严重的区域主要分布在以武汉为中心的经济圈;在东北地区,以大连、沈阳、长春和哈尔滨为中心的城市区域人为热污染也较为严重;而在西北和西南的大部分地区,人为热排放量很小,仅在以成都、重庆为中心的区域较大.历年来全国年均人为热的最大值都出现在上海,其中2010年最大,为113.5W/m2,上海人为热排放的年均值增长明显,可达到0.6W/m2/a.随着城市化进程的加快,人为热的排放愈来愈强,热污染对城市和区域的气候以及空气污染的影响也会越来越重要.     

基于TM影像的城市地表湿度对城市热岛效应的调控机理研究

论文以探究城市热岛效应调控机理为研究目的,以徐州地区1985-2010 年夏季四期Landsat TM影像为研究数据,应用单窗算法、K-T变换、空间叠加分析以及缓冲区分析等研究方法,对徐州市城市热岛时空变化特征进行了反演,重点对徐州市城市热岛强度的调控机理进行了分析并提出了通过K-T变换提取表示城市建成区内部植被与水体覆盖程度的城市地表湿度(ULSW)这一新指标.研究结果显示:城市地表湿度显著区对城市热岛效应起到了有效的调控作用,并且随着城市地表湿度值的提高,区域内部以及周围环境的温度都会随之下降.城市地表湿度指标对于城市热岛效应的调控水平具有一定的代表意义.     

CRH_1型动车组一等座车厢火源热释放速率研究

为了得到不同通风条件和旅客行李条件下CRH1动车组一等座车厢的火源热释放速率的合理取值范围,以CRH1型动车组一等座车厢为研究对象,以锥形量热仪和大型量热仪测定的高速客车车体内材料和行李的燃烧性能为输入参数,运用FDS软件模拟6种火灾场景下车厢的火源热释放速率随时间的变化规律,分析了通风条件、火灾荷载密度、可燃物间距和行李重量对车厢火源热释放速率的影响。研究结果表明:在不考虑旅客行李时,各种通风条件下车厢最大火灾热释放速率在1.86-4.34MW之间;在车门与车窗开启条件下,与不考虑旅客行李的情况比较,人均携带10、20kg行李时,火源热释放速率分别增加了12.84、15.38MW,增加的幅度分别为570%和684%。     

珠光体耐热钢膜式水冷壁制造工艺优化

本文简要介绍了膜式水冷壁管屏制作工艺过程和珠光体耐热钢水冷壁管屏制造过程中易产生的缺陷分析,通过改进优化成排弯曲模具,焊前清理、预热,避免外侧管椭圆度、焊接气孔、咬边等缺陷。结合工艺试验分析了珠光体耐热钢管屏热矫正后不恰当的冷却方式引起延迟裂纹的原因,从而总结出珠光体耐热钢水冷管屏焊后热矫正时需特别注意的加热方法、加热温度及冷却方式,确保产品质量。     

API Standard 521 new alternative method to evaluate fire relief for pressure relief device sizing and depressuring system design

Since the 1950's, API Standards have provided guidance on determining relief loads for equipment exposed to pool fires. The API method is empirical based on tests performed in the 1940's. There is increasingly widespread interest in analytical methods based on heat transfer principles to model fire heat input. The API committee agreed to include an analytical method in the 6th edition of API Standard 521 to establish relief loads for pressure relief devices and to design depressuring systems for the fire scenario. The analytical method provides more flexibility than the empirical method but has limitations (e.g., too many permutations are possible leading to potential under-sizing of the pressure relief device).This paper discusses the basis for the empirical method in API Standard 521 and provides comparisons of the empirical and analytical method with two more recent large-scale pool fire tests. This pool fire test data indicates that the empirical method will provide a conservative estimate of pool fire heat input for most applications and is still the method of choice when designing pressure relief systems. However, these recent tests indicate the empirical method needs to be modified when a vessel or equipment is partially confined by adjacent embankments or walls equal or greater than the vessel height. In such cases, the wetted area exponent should be 1.0 instead of 0.82.The analytical method is useful in determining time-versus-temperature profiles for heating unwetted vessels of varying wall thicknesses and materials of construction. These profiles, which depend upon the type of fire (e.g., unconfined pool fire, jet fire, etc.), can be combined with tensile strength and stress-rupture data to specify a depressuring system's pressure-versus-time profile. This will minimize failure and/or mitigate the effects of failure due to overheating from fire exposure.     

热媒炉导热油的清洗与更换

对热媒炉导热油系统结垢的原因进行分析.介绍了热媒炉导热油系统清洗的方法,比较各种清洗方法的异同.对清洗更换导热油时的注意事项进行说明,对试运情况及取样化验数据进行分析.     

Application of Zr(IV) tungstate for removal of metal ions from aqueous solutions

A heteropolyacid Zr(IV) tungstate-based cation exchanger has been synthesized. An amorphous sample, prepared at pH 1.2 and having a Na⁺ ion exchange capacity of 0.92?meq?g^?1, was selected for further studies. Its physicochemical properties were determined using Fourier transform infrared spectrometer, X-ray diffraction, thermogravimetric, and scanning electron studies. To understand the cation exchange behavior of the material, distribution coefficients (K _d) for metal ions in various solvent systems were determined. Some important binary separations of metal ions, namely Mg²⁺–Bi³⁺, Cd²⁺–Bi³⁺, Fe³⁺–Bi³⁺, Th⁴⁺–Bi³⁺, and Fe³⁺–Zn²⁺, were achieved on such columns. The practical utility of these separations was demonstrated by separating Fe³⁺ and Zn²⁺ ions quantitatively in commercial pharmaceutical formulation. The cation exchanger has been successfully applied also for the treatment of industrial wastewater and a synthetic mixture. All the results suggests that Zr(IV) tungstate has excellent potential for the removal of metals from aqueous systems using packed columns of this material.     

锅炉废气流化床污泥干化塔的热力计算与分析

利用锅炉尾部废烟气(120～190℃)干化市政污泥,降低污泥含水率可达到后继合理利用。从三方面对污泥干化进行了分析:1)干燥后污泥含水率与污泥处理量关系;2)入口烟温、流量与污泥处理量关系;3)干燥后烟气相对湿度影响因素分析。结果表明:提高入口烟温、流量,污泥出口含水率都可以提高污泥处理量,高入口烟温、流量下,污泥处理量受含水率的影响更大;污泥出口含水率高时,入口烟温提高使污泥处理量提高增大显著;入口烟气流量愈高,入口烟温提高对污泥处理量的增加愈大。干燥后烟气相对湿度与入口烟温有关,干燥之后的烟气的相对湿度离饱和状态较远,此温度范围内的出口烟气湿度还有较大的余量。     

Fluent软件在地表水源热泵系统温排水数值模拟中的运用

运用Fluent软件对重庆市嘉陵江化龙桥段瑞安新天地江水水源热泵系统尾水排入受纳水域的过程进行二维数值模拟,选取Fluent中非耦合、隐式求解器对模型内的定常流动进行求解,得出受纳水域受水源热泵系统温排水影响后的温升面积和温度梯度。结果表明:在温排水流量为2.0×103 m3/h、温差为4℃的条件下,计算该水域沿水流方向温升超过1℃的最大影响距离为150.4 m,温升超过1℃的水域面积约为1 525 m2,为模拟江水面积的8.59%。选取1℃温升值作为温升带的边界控制值,并在热泵系统最大负荷工况下,根据W=Q×ΔT计算研究水域热环境容量为19.402 m3.℃/s,剩余热环境容量为17.736 m3.℃/s。根据地表水环境质量标准,该工程温排水量小于受纳水域的热承载力,不会对受纳水域生态环境造成热污染。     

工业和建筑固体废弃物再生研究

为了减轻我国的工业/建筑固体废弃物的污染压力,通过对工业和建筑固体废物、粉煤灰、水泥以及外加剂的组合配比实验,优化制作具有轻质高性能的混凝土建筑砌块的方法,并对所研制的混凝土砌块的强度和导热性能进行了测试,最终结果显示砌块性能良好。预计此类复合建筑材料可以在未来的市政建筑中发挥应有的作用。