共查询到20条相似文献,搜索用时 109 毫秒
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众所周知,浮在水面上的帆船,借助风力就能前进。在这种思想启发下,早在20世纪20年代,就有人设想,能不能在太空也扬起一张大帆,借助太阳光压顶在帆上,也能推着飞船在宇宙空间里前进呢? 相似文献
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在新一轮产业发展中,奉贤中小企业异军突起,在提速中争取主动。年前,三一重工在临港奉贤分区开工建设,揭开重大装备制造业在远郊奉贤崛起的序幕。虎 相似文献
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《京都议定书》实施世界拉开温室气体减排大幕 总被引:2,自引:0,他引:2
2005年2月16日,是一个令全世界关心全球气候变化和环境问题的人士欢欣鼓舞的日子,在经过了漫长的8年后,<京都协定书>终于得以实施.在京都、在波恩、在北京、在悉尼、在布鲁塞尔……全世界都成为了宣传<京都协定书>的大舞台. 相似文献
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对锅炉憋压 /节流运行技术提高热网运行效率的方法给予了详细的阐述 ,它产生于塔里木油田某转油站 ,并成功地应用于该油田的其它转油站。锅炉憋压运行技术的研究是基于工程热力学理论、流体力学理论和传热学理论。在供热系统中热动力式疏水器在原始的运行系统下蒸汽流失严重 ,而在新的运行系统下只疏水不疏汽 ,蒸汽损失较小 ;通过对外输原油所需热量、换热器换热量、实际用汽量以及转油站所需锅炉加热量等的比较计算分析 ,论证了锅炉憋压运行技术对高出力、低负荷运行 锅炉热网具有一定的节能效果 ,操作简单且不需要对系统进行改造 相似文献
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一种只在裸屋顶上铺放5cm厚种植基质的"轻型屋顶绿化技术",具有明显的夏降温、冬保温作用。内外表面温度绿化屋顶与裸屋顶相比作用明显:全年波动幅度小;一日间温度波动平缓,变化幅度极小;夏季不受高温影响,冬季不受低温影响的"夏降温、冬保温"效果明显;内外表面日均温度"夏低冬高",内表面春、夏、秋三季低6%~10%左右,冬季高20%以上;屋顶绿化可以减少房间空调用电量18%,室外温度越高,屋顶绿化的节电效果越大。 相似文献
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以燃料电池客船“Water-Go-Round”号为对象,利用FLUENT软件模拟燃料电池客船舱内管道发生氢气泄漏并引发爆炸的情况,研究不同舱室氢气点火爆炸事故的影响规律。结果表明:可燃氢气云被点燃后,爆炸超压波自点火位置向四周迅速传播,点火位置对超压波的分布影响较大;控制舱爆炸时,超压强度最大,对船体超压危害最大;乘客舱爆炸强度最小,但超压中心分布在乘客舱,超压对乘客造成的危害最大;船舶舱室燃烧火焰温度主要由可燃氢气云的分布决定,燃料电池舱的火焰衰减趋势基本相同;乘客舱受到的高温危害较低,船艏舱无燃烧火焰的高温危害。 相似文献
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Exergetic evaluation and comparison of quintuple effect evaporation units in Indian sugar industries
Present work analyzes and compares two quintuple effect evaporation units with and without heat recovery devices being employed. It is based on actual operational data of sugar plant. This study is primarily based on exergy analysis. Case A is a quintuple effect evaporation unit without heat recovery devices, while case B is with heat recovery devices. The average exergy efficiency is found to be 70.53% for case A, while it is 86.71% for case B. Highest exergy destruction for case A is in second effect with a value of 1562.20 kW, and for case B, it is for the first effect with a value of 1871.68 kW. Steam economy for case A is 1.99, while for case B, it is 3.46. This is due to high evaporation rates and heat recovery devices being employed for case B. The fifth effect evaporator in case A and first effect evaporator in case B are found to be the least efficient components from exergy point of view. As energy economy is concerned in terms of exhaust steam demand, case B is more attractive than case A. However, in terms of exergy, case B is less sustainable than case A. A parametric study indicated that increase in the exhaust/inlet steam temperature is highly disadvantageous in terms of exergy and quality of the end product. The authors expect that the exergy analyses results would facilitate the designers and professional practioners in the field of sugar engineering in furthering the goal of improving energy systems. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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淮河流域洪涝时空分布规律 总被引:1,自引:0,他引:1
基于淮河流域18个分区1953~2007年主汛期(6~8月)降水资料,采用Z指数法、数理统计方法和经验正交函数分解(EOF)研究了淮河流域洪涝的时间分布规律及空间分布特征。结果表明,淮河流域汛期各月发生洪涝几率的趋势变化不显著,但6、7月发生洪涝的几率比8月大;6月在1988后发生重涝、大涝频率较1988年前明显增加;6、8月发生洪涝事件主周期较长,分别为11、10年,7月较短为3年,7月需注意旱涝急转;淮河流域洪涝类型主要为流域一致型,即梅雨型洪涝,洪涝中心在润河集至蚌埠区间;淮河流域洪涝空间分布特征受地形、地貌的影响,西南山区汛期发生洪涝的可能性比西北平原大,西南部洪涝中心位于大别山的腹地横排头附近。 相似文献
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《International Journal of Hydrogen Energy》2022,47(73):31165-31173
Increasing energy needs and reducing greenhouse gas emissions require immediate studies on carbon-free energy solutions, namely hydrogen. There are numerous methods among the production methods of hydrogen in a green manner. Hydrogen, which is then primarily obtained as a result of the separation of water with thermochemical cycles, is an environmentally friendly and sustainable hydrogen production method. In this study, the Cobalt–Chlorine (Co–Cl) cycle, which is one of the new thermochemical cycles, is examined in detail in terms of thermodynamics. There are four reactions in the Co–Cl thermochemical cycle. These are listed as the hydrolysis reaction in which hydrogen is obtained, the thermolysis reaction in which oxygen is obtained, the reduction reaction and finally the hydrochlorination reaction. According to the results of the analysis performed kinetically with the Aspen Plus software, the exergy efficiency of the cycle is calculated as 33%. When the exergy destruction of all reactions is compared, it is seen that the greatest exergy destruction occurs in the hydrolysis reaction, and the lowest exergy destruction occurs in the hydrochlorination reaction. The fact that the exergy efficiency is high when evaluated in terms of kinetics shows that the cycle is feasible in terms of thermodynamics. In addition, the costs of the cycle are to be considered in the future studies as it is an important criterion. 相似文献
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运用ADAMS软件对汽车发动机进行振动分析时,鉴于在ADAMS环境中建模存在的诸多困难,提出了用Pro/E软件建立发动机模型,然后利用接口软件Mechanism/Pro将发动机模型导人到ADAMS环境中进行分析的方法,为研究发动机振动问题提供了方便,能够建立更加准确的模型,获得更加良好的仿真结果,为进一步改善发动机振动问题奠定了基础. 相似文献