取暖锅炉耗煤量核定方法探讨

利用采暖建筑所需的理论热负荷值,对单一取暖锅炉单位供暖面积所需耗煤量进行估算,通过估算出的耗煤量,结合国家现有的煤种、治理装置脱硫、除尘效率等参数,可以计算出燃煤锅炉单位取暖面积主要污染物排放量,为排污收费提供科学的依据。     

气动热效应对某红外导引头影响分析

导弹高速飞行时所产生的气动热,将影响探测器正常成像质量,从而影响导弹的命中精度和导引头的作用距离.由于新型隔热材料的采用,气动热对导引头性能影响减小很多.采用ANSYS软件对某导弹的气动热效应进行仿真,为高速导弹气动性能分析及其环境失效研究提供参考.     

兰州冬季城市烟雾层辐射效应的观测分析研究

冬季兰州城市上空形成浓厚的烟雾层。利用1990年11月兰州大学和离城市地面625m高南山顶的辐射和探空资料,分析和计算了烟雾层的辐射效应。兰州城市烟雾层具有浑浊度系数大波长指数小的特点。对到达地面的太阳辐射有很强的削弱。浑浊度系数最大时,烟雾层内的平均加热率为6.16℃/d,。大气层对各波段的消光强弱不同,对可见光削减最大。同时烟雾层使到达兰州地面的大气逆辐射比南山顶增加5.2％,总的入射辐射比南山顶小5.6％,地面辐射差额比南山顶小67.8％。烟雾层的存在增加了城市边界层的稳定性。     

自然老化木材燃烧过程热行为特性研究

为提供古建筑火灾数值模拟及风险评估的基础理论,从自然老化角度入手,选取经过长久自然老化的建筑服役木材作为研究对象,通过扫描电镜(SEM)及热物性试验对比分析自然老化木材与参照木材的外观形态及热传导特征;采用差示扫描量热DSC法,研究自然老化木材在燃烧过程中热释放的阶段特性,分析不同升温速率对老化木材热行为影响特征;基于...     

COMPARISON OF DESIGN STORM CONCEPTS USING CONTINUOUS SIMULATION WITH SHORT DURATION STORMS1

ABSTRACT: The objectives of this paper were to test the ability of various design storm distributions to simulate the actual rainfall pattern and to compare the runoff rates used in the design of stormwater management devices in the State of Florida using continuous simulation approach. The analyses were performed for four gaged stations to evaluate the applicability of design storm distributions in different parts of the State of Florida. The approach used in this study compared the peak runoff rates from design storms based on the various distributions to those that would result from actual rainfall events. A series of continuous runoff rates were developed through the use of actual fifteen-minute recorded rainfall data, Horton type infiltration decay and recovery rate, and a continuous simulation model. The runoff rates were analyzed using frequency distributions to obtain peak runoff rates associated with different return periods based on the assumption that the continuous simulation approach closely predicts the actual runoff rates from the gaged stations. The results show that the behavior of the design storm distributions varies for different watershed characteristics in different parts of the state. The study also suggests that in general the Florida Department of Transportation and the Suwanne River Water Management (FDOT/ SRWMD) distributions appeared to agree with the continuous simulation results.     

哈大绥城市“十三五”期间大气环境容量分析

根据2016—2020年哈尔滨市、大庆市、绥化市(以下称哈大绥)国控环境空气自动监测站的SO₂、NO₂、PM_2.5监测资料,统计年鉴中行政区划、污染物排放及气象等监测数据,分析哈大绥区域环境空气质量的变化趋势和测算因子,采用A值法核定了哈大绥区域SO₂、NO₂、PM_2.5的大气环境容量。结果表明:哈大绥SO₂、NO₂、PM_2.5 3项污染物采暖季的大气环境容量均呈逐年递增趋势。通过计算环境承载能力发现,哈大绥SO₂、NO₂、PM_2.5 3项污染物在非采暖季均具有高承载能力,哈大绥非采暖季环境容量高于采暖季。哈尔滨的个别污染物仍然处于临界超载状态,为减少重污染天气,应进一步削减采暖季污染物排放量。     

等效阻尼比对基于位移的抗震设计的影响分析

等效阻尼比是基于位移抗震设计中确定等效周期的一个关键参数。通过对不同研究者提出的等效阻尼比模型进行比较研究,重点讨论了滞回模型、延性系数和等效周期对等效阻尼比的影响。结果表明,不同等效阻尼比模型的总体变化趋势是一致的;滞回模型对等效阻尼比有很大影响,Ramberg-Osgood模型的等效阻尼比是Flagshaped模型的2.56倍;等效阻尼比随着延性系数的增大而增大,尤其在μ=2～4范围内变化幅度最大;短周期与中长周期等效阻尼比相差2倍多,故等效周期小于1 s时,必须考虑其对等效阻尼比的影响。     

电气火灾残留物的SEM分析方法研究

通过分析电气火灾的形成原因,总结出该类型火灾的残留物种类。然后利用电焊机和电阻炉等设备分别制备出铜铝导线的一、二次短路熔痕和火烧熔痕,电热丝的通电过热和火烧熔痕,并运用了目前一种新式有效的显微结构分析工具——扫描电子显微镜,对以上样品的表面进行微观形貌的观察、比较与分析。通过分析讨论,可以发现电气火灾残留物在火灾前后其表面的微观形貌特征存在明显不同。根据这些特征能够很轻易的鉴别出电气设备在火灾发生前的使用状态,从而推断出火灾是否由该电气设备引发而起。此项结论能够为从事火灾调查的人员对电气火灾原因的准确认定提供可靠依据,也能够为扫描电子显微镜技术的应用领域进行拓宽提供一些帮助。     

Physico-chemical characterization of Residual Household Waste for energy recovery in insular territories: Case study of Reunion Island

Waste-to-energy is a promising approach to face the current challenge of waste overproduction in Reunion Island, a French territory. In this particular context of an isolated and tropical territory, it is essential to study the properties of potential feedstocks to choose the most appropriate conversion process. This article reports on the composition of Residual Household Waste from Reunion Island and its physico-chemical parameters. Twelve representative samples of Residual Household Waste were subjected to thermal and elemental analysis. The results showed that their composition had a significant influence on the physico-chemical properties, including calorific value. Residual Household Waste from the selective sorting (rich in wood, plastic, and sanitary textiles) as well as dry mixed RHW are the most interesting for energy recovery. Due to their high volatile matter and high carbon content, and their low moisture content, these types of waste have a high calorific value exceeding 18 MJ/kg. Furthermore, the RHW sample comply with the environmental and health criteria applied by French regulations concerning halogen and heavy metal. Thus, it seems that Residual Household Waste can be an alternative to conventional fuels used in incineration or pyro-gasification processes. However, the study also points the need for a pre-treatment process for these wastes. Indeed, it is necessary to sort them correctly in order to avoid the risks of pollution and important maintenance. And more importantly, drying beforehand is unavoidable to improve combustibility and obtain optimal energy conversion.     

采煤塌陷对地表植物群落特征的影响

为了研究采煤塌陷对地表植被组成及其多样性的影响,对陕西省神府-东胜补连塔煤矿采煤塌陷区不同塌陷年限(2、7、12、17 a)区域和未塌陷区域(对照)植被进行抽样调查与分析. 结果表明:该区域共有14科39属46种植物,主要为草本植物;采煤塌陷对植被种类组成、物种分布有很大影响,导致植物种类显著减少31.03%~44.83%. 塌陷区优势种较对照区有较大变化,优势种由多年生草本植物演变为一二年生草本植物;但是不同塌陷年限区域植物优势种基本稳定,主要为看麦娘(Alopecurus aequalis)、烛台虫实(Corispermum candelabrum)、刺叶藜(Chenopodium aristatum)等. 采煤塌陷导致植株密度显著下降58.62%~68.00%、物种丰富度显著下降17.43%~27.00%、Margalef丰富度指数显著降低4.07%~22.76%,但植被盖度差异不显著. 采煤塌陷显著影响植物群落多样性,其中,塌陷12和17 a样地植被Margalef丰富度指数和Shannon-Wiener多样性指数较塌陷2 a样地显著提高. 群落排序结果表明,物种分布与塌陷有明显相关性. 塌陷区植株密度及其植被组成中多年生草本种数很难恢复到对照区水平,植被恢复进程十分缓慢.