锅炉烟气余热用于木材干燥的节能改造

针对广东某胶合板企业2台蒸汽锅炉排烟温度高,不能根据工序用热需求实现能源梯级利用的问题,提出了锅炉烟气余热利用方案。根据干燥窑干燥木材的特点,将蒸汽锅炉的烟气引入干燥窑内的换热器用于干燥木材,每年通过回收利用的锅炉烟气余热折合标煤达439t。     

新能源公交车的推广应用

近年来，随着石油燃料的消耗增加，能源消耗以及环境问题逐渐得到了广泛的关注，新能源汽车（文章是指新能源公交车）的技术研发和产业化发展受到的重视程度越来越高。中国的经济发展越来越快，近几年汽车销售量增长迅速，石油消耗量大幅增加，导致二氧化碳等温室气体排放量大幅增加。文章主要从国家政策、车辆使用情况、配套充电设施建设等几个方面浅议新能源公交车在推广应用中面临的机遇和挑战。     

福建省将乐县金溪建电站前后雨水情变化分析

本文通过对将乐县金溪建电站前的1953～1978年、建电站后的1990～2009年雨水情进行分析,结果表明:自然状态下的将乐县(1953～1978年)无论雨水大小,每年都有洪水超过警戒水位,年最大洪水发生时间在4～7月;1953～1978年有16年的当年最大洪峰水位发生在当年最大日降雨量当日至第16日内,频率为61.5...     

Environmental performances of giant reed (Arundo donax L.) cultivated in fertile and marginal lands: A case study in the Mediterranean

Perennial rhizomatous grasses (PRGs) tend to have a high yield combined with a low environmental impact. Cultivation in marginal or poorly cultivated land is recommended in order not to compromise food security and to overcome land use controversies. However, the environmental impacts of using different types of soil are still unclear. We thus assessed the environmental impact of two giant reed (GR) systems cultivated in a fertile soil (FS) and in a marginal soil (MS) through a cradle-to-plant gate LCA. We analyzed energy balance, GHG emissions (including LUC, not including iLUC), and the main impacts on air, water and soil quality. In both systems the annualized soil carbon sequestration was more than twofold the total GHG emitted, equal to −6464 kg CO₂eq ha⁻¹ in FS and −5757 kg CO₂eq ha⁻¹ in MS. Overall, soil characteristics affected not only GR yield level, but also its environmental impact, which seems to be higher in the MS system both on a hectare and tonne basis. The production of GR biomass in marginal soil could thus lead to higher environmental impacts and a more extensive land requirement.     

特大型沼气工程温室气体减排效益分析——以“海南澄迈日产3万Nm3车用沼气项目”为例

根据国际通用的温室气体减排计算方法，对海南澄迈日产3万Nm3车用沼气工程所带来的主要温室气体减排量和减排效益进行了估算分析。结果表明：项目每年可减少温室气体排放53 560 t(CO2当量)，以上海碳交易市场近年平均交易价格(39.23元/t CO2)计算，可带来210.12万元的经济效益。     

第24届冬奥会举办地空气质量特征及环境因子响应机制

空气质量问题是近些年来广受关注的问题，尤其对国际性盛会冬奥会而言，举办地的空气质量也是其能否举办成功的重要评估标准。为评估冬奥会举办地近6 a空气质量状况及动态变化环境相应机理，该研究收集了2014年以来3个冬奥会场馆所在地（北京延庆、奥体中心和河北张家口）的空气质量数据，分别分析了3个监测点的6个空气质量指标（CO、NO₂、O₃、SO₂、PM_2.5、PM₁₀）的浓度动态，并结合2016年奥体中心的气象数据分析了6个指标环境因子的响应机制，结果表明:1)张家口空气质量相对最佳，PM_2.5达标率均在80%以上，但春季大颗粒物污染仍需治理；2)2014-2019年3个监测点的空气质量有明显改善，尤其张家口SO₂从37.50 μg/m³（2014）降至11.06 μg/m³（2019），但截至2019年奥体中心NO₂仍高于国际标准，气体污染物仍是其治理的重点；3)CO和NO²日变化呈“U型”，O³和SO²为“单峰型”，CO、O₃、SO₂季节变化明显。各空气质量指标的主要影响因子分别为CO-太阳净辐射（R_n）、NO₂-太阳净辐射（R_n）、O₃-空气温度（T_a）、SO₂-空气温度（T_a），其中风速（Ws）与各空气质量指标呈负相关关系；6个指标年最大值（7.6 mg/m³、155.5、186.9、68.4、373.2 μg/m³和465.5 μg/m³）均出现在Ws<1 m/s时；然而，由于各空气质量指标的来源及彼此转换，各空气质量指标之间的相关性强于与环境因子的相关性。     

美国油气管道基本失效概率评估方法及启示

为充分利用油气管道历史失效数据,减少失效概率评估过程中的主观性,提出油气管道基本失效概率的概念及评估方法。对美国管道及危险物品安全管理局数据库的油气管道里程数据、事故数据及失效因素数据进行全面分析,采用基于事故统计的方法评估油气管道基本失效概率。结果表明:美国危险液体管道、输气集气管道、配气管道发生一般事故的基本失效概率分别为1.29次/(10^3 km·a)、2.17次/(10^4 km·a)及4.08次/(10^5 km·a),发生较大事故的基本失效概率分别为4.58次/(10^4 km·a)、1.41次/(10^4 km·a)及2.38次/(10^5 km·a),发生重大事故的基本失效概率分别为9.09次/(10^6 km·a)、9.79次/(10^6 km·a)及1.11次/(10^5 km·a)。美国基本失效概率可作为油气管道失效概率评估的基准线,也可作为风险可接受标准的依据,但不能直接应用于中国管道风险评价,需对其进行修正,建立适用于中国管道的失效数据库。     

浅谈地下车站侧墙大块定型移动模架施工技术

随着城市地铁的飞速发展,地铁车站在条件满足的情况下大都采用明挖法施工。在施工主体侧墙时采用满堂红支架法施工,但因施工时工期较长且易存在一些质量通病,因此,近年来大块定型移动模架被得到了广泛的应用。     

半地下带保温夹套发酵罐的应用

通过对半地下带保温夹套的发酵罐与普通发酵罐24 h的温度变化和6 d的产气量的对比试验分析,结果表明:采用半地下带保温夹套发酵罐发酵,24 h的温度变化缓慢,受外界温度变化影响小,高温持续的时间较长,利于微生物发酵;产气总量多,持续时间长。     

Chemical and nutritional characteristics of Cannabis sativa L. co-products

Cannabis sativa L. is an annual herbaceous plant. It was used for centuries to obtain different products. In the last century, hemp cultivation was forbidden due to the psychoactive effects of tetrahydrocannabinol acid (THCA). In the last years, new strains, characterized by high cannabidiolic acid (CBDA) and low THCA level, were developed renewing the interest in hemp cultivation to obtain food or to extract essential oils from flowers. All these processes produce many residues with different chemical–physical characteristics. In order to evaluate their potential use also in animal nutrition, some hemp co-products were evaluated. Two different co-products of seed processes (flour and oil) and two co-products obtained trimming the flowers, differing in granulometry were used. The samples were analysed for chemical composition and evaluated in vitro using the gas production technique with buffaloes' ruminal inoculum. All hemp co-products showed interesting nutritional characteristics, such as crude protein content always higher than 20% on a dry matter basis, and high neutral detergent fibre concentration partially lignified. The in vitro gas production parameters at 120 h of incubation showed quite low fermentability testified by the low organic matter degradability and cumulative gas volume (OMD from 28.09 to 45.64% and OMCV from 110 to 164 ml/g, respectively). Also, the methane produced after 24 h of incubation was particularly low (from 1.78 to 11.73 ml/g dOM). These results could be due to the high lipid and ash amounts or to the CBDA content that probably affected the CH₄ formation processes. According to preliminary results obtained by this study, it is possible to hypothesize that these co-products could be useful to mitigate the methane production into the rumen. Further studies are necessary in order to evaluate the correct inclusion into the diet for ruminants.