首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 406 毫秒
1.
Compared to bi-fuel engine,it uses completely CNG(Compressed nature gas) to replace diesel which can save more oil fuel than bi-fuel engine that reffited diesel engine into CNG engine. A 4102 diesel engine is refitted into CNG engine and a mechanical ignition timing system is designed by the method of gear and belt. The principles and the construction of the system is introduced and the characteristics of the design is analyzed. The system performed well and had good liability when run in a platform. Compared with the previous one, it kept higher dynamic character and emitted lower. It is a cheap one and can be use to reform the diesel engines.  相似文献   

2.
在压缩天然气汽车(CNGV)的改装过程中,CNG喷射器喷嘴孔径这个工艺参数,极为关键却又难以把握。为了提高安装作业的效率及精度,探究出一种能辅助安装者更快更准地确定所需孔径的方法,提出了以模糊模式识别原理的算法,根据待改装车辆的发动机功率、行驶总里程和当前火花塞使用中的行驶里程这3个指标,对喷嘴孔径的尺寸进行识别,以实现在CNG系统安装前对孔径进行确定。在MATLAB中对该算法进行验证时,发现采用随机性更好的分组抽样且对算法的数据运算过程进一步匹配修正后,孔径的识别精准性显著提高。经过与此前的实际安装记录数据的核对,最终证实了该算法的可行性及准确性。  相似文献   

3.
DNA甲基化是表观遗传学修饰的重要研究内容之一,在植物生长发育和响应逆境胁迫等过程中起重要作用,其中水分胁迫是对植物生长发育最具危害的逆境胁迫之一。为探索马铃薯DNA甲基化与水分胁迫之间的关系,本研究采用PEG-6000模拟水分胁迫处理两个马铃薯品种‘青薯9号’和‘大西洋’,在PEG0%(对照),5%和10%浓度下,利用MSAP技术检测‘青薯9号’和‘大西洋’甲基化水平变化情况。结果表明:在相同条件下,抗旱型品种‘青薯9号’甲基化水平高均于干旱敏感型品种‘大西洋’。在0%(对照)、5%和10%PEG胁迫下,‘青薯9号’MSAP比率为42.49%、38.14%、49.21%,甲基化水平与对照相比先降低后升高,‘大西洋’MSAP比率29.17%、22.92%、17.58%,甲基化水平逐渐降低。经统计,5%PEG和10%PEG胁迫下,‘青薯9号’和‘大西洋’均出现甲基化和去甲基化现象,其中‘青薯9号’甲基化和去甲基化比率分别为10.92%、6.43%和11.98%、15.36%,‘大西洋’分别为1.59%、8.22%和42.18%、24.34%,甲基化变异模式以去甲基化为主。‘青薯9号’和‘大西洋’均能发生CNG、CG和CG/CNG位点的甲基化和去甲基化,在水分胁迫下会产生较多的CNG和CG/CNG位点。本研究结果为探究马铃薯抗旱机制提供了理论基础。  相似文献   

4.
The optimal operation in hydroelectric station unit is me opumum problem,which include unit commitment,load distribution and unit maintenance. The authors research the optimal operation in units in hydroelectric station of Gezhouba by the genetic algorithm and dynamic programming to satisfy the demand of economic operation of Gezhouba. They arrange and organize the program of the units in r6ason to go for the better benefit and satisfies security, credibihty and high quality of electric production . These methods can work out the most optimum result. When the head of water and the flux is confirmed they can distribute the flux to the units to realize the optimal operation of the scheduling in Gezhotlba.  相似文献   

5.
江厦潮汐电站库区滩涂水产养殖现状及对策   总被引:1,自引:1,他引:0  
以江厦潮汐电站库区滩涂水产养殖现状为例,分析2011年江厦潮汐电站滩涂水产养殖的发展现状,包括水产养殖成鱼的成本构成情况及收益水平,并探析其养殖经济效益的主要影响因素,阐述电站库区滩涂水产养殖存在的问题,并提出相应的对策。研究结果显示:虽然库区滩涂进行水产养殖的养殖主体平均收入水平高于温岭市农村居民人均纯收入水平,但其收入有“被增长”现象;养殖水域污染及富营养化的现象有待解决;依然是以传统的养殖产业模式为主,可尝试开发生态渔业。  相似文献   

6.
It is two main factors that the refrigerant leakes and preheated in compress process for the discharging of the screw refrigeration compressor. The size of them directly is related to the form of the screw and the precision of the screw processed, and the screw cooled etc. Each compressor factory is different from others for designing and processing the screw. In the engineering design, it is difficult to calculate volumetric flow rate of the screw refrigeration compressor. The main factor of the volumetric flow rate is analyzed for the screw refrigeration compressor. A method of calculating the volumetric flow rate is inferred and checked. It can be for the use of engineering design  相似文献   

7.
从理论上分析了活塞式压缩机与螺杆式压缩机的性能特点,以实例论证了螺杆式压缩机比活塞压缩机在冷库系统的实际运行中节能效果明显.  相似文献   

8.
This paper describes the noise mechanism of rotary vane compressor JSS -96 by the method of running independently, spectrum and the measurement of the sound intensity. The noise sources of this type compressor mainly include noise of electromotor, outlet noise and intake noise. Electromotor noise and outlet noise among them have most influence on the compressor noise. This is the further basis of noise control for rotary vane compressor.  相似文献   

9.
The steady flow resistance in the Three Catalytic Converters(TWC) with guide components of CNG(Compressed Natural Gas)cars is simulated.The location set guide flow equipment has great impact on pressure losing which can be adjusted to the optimal while adopting some measures.Pressure losing by adding combination flow-guide plate which can evidently improve flow field uniformity has a little impact on engine.Pressure losing will be small while adopting optimal location and guiding-flow construction.  相似文献   

10.
Analyse of Compressor Sound Quality   总被引:1,自引:0,他引:1  
By of Stevens steady wide frequency noise loudness and Fastl total sensation noise calculation method, sound quality evaluation of the noise left and back-end face was studied before the compressor improved and after the minipore muffler installed. The research indicates that the compressor noise is reduced, at the same time, the loudness left the compressor and the back - end face is reduced by 10.25 sone and 13.3 sone respectively. The rate reduced is over 40%. The total sensation noise is reduced by 12.5 noy and 15 noy, the rate achieved is over 45%. It is very perfect to improve the compressor sound quality with the use of minipore muffler.  相似文献   

11.
The steady flow in the catalytic converters of CNG was simulated. The gas can breakaway in the entering pipe and the flow of the gas can convergence well in the exhaust pipe. The flow distributing mainly depends on the flow capability of the expanding pipe. The pressure falls apparently in the carrier of catalytic converters. The noble metals in the center of the catalytic converters are consumed more quickly than the edge zone.  相似文献   

12.
为促进贵州辣椒渍涝灾害气象指数保险业务的开展,降低农户受渍涝导致的经济损失风险,根据笔者制定出的渍涝等级标准处理贵州省84个国家气象站30年间降水量数据,得出各站点各级渍涝灾害频率,以及各站点的纯保险费率。利用克里金差值绘制出各级渍涝灾害频率分布图以及纯保险费率分布图,可以明显看出受渍涝灾害影响较大的辣椒种植地区主要集中于西南部以及南部部分区域;受渍涝灾害影响较小的辣椒种植地区主要在贵州西部、北部以及东部部分区域。纯保险费率较高的地区主要在贵州西南部以及东南部分地区,当免赔额不同时纯保险费率会有较大差距。辣椒渍涝气象指数保险在贵州有着较好的发展前景,不仅可以降低农户受渍涝灾害损失的风险,还能促进贵州辣椒产业持续稳定增长。  相似文献   

13.
The paper depends on the new three theories(theory of dissipative structure.catastrophe theory and synergetics)as a guide,and establishes a developmental strategy planning forthe circumjacent reservoir regin of Longtan hydropower project which is the dragon head station often-cascade development along the Red Water Rlver,and adopts grey systems theory to predict theeconomic development of the reservoir region, The computational results show that the grey predic-tion model,the theory and methods of grey systems applying to economic system prediction are effi-clent.  相似文献   

14.
This paper propose an approach to reduce the regular pulse noise from ofQD55A air flow refrigerator compressor.The Rource is analysed by spectral a nalyeis techiques.Thenoise level is droped 4dB via massive preduction testing verification,and a desirable result on noise reduction has been obtained.  相似文献   

15.
利用卢氏站2014年新、旧站址正式气象观测记录月报表数据,采用通用差值统计方法,分别计算气温、最高气温、最低气温、相对湿度、2 min平均风速的差值平均值、年差值标准差等;风向一致性采用相符率统计。通过上述计算结果对卢氏新、旧站址的气象资料进行对比、分析与评估工作,并分析引起变化的原因,以期为站址迁移及迁站后的预报服务工作提供参考。结果表明:新址年平均气温和年最高气温比旧址分别低0.3℃、1.1℃,年最低气温比旧址高0.1℃,年最高气温相差最大;年平均相对湿度差值为0%,说明相对湿度受站址迁移的影响不大;新址风速大于旧址,年平均风速偏大1.0 m/s;旧址与新址年风向相符率只有26%,两站风向一致性很差。通过对新、旧站址各气象要素的差异研究,为气象预报服务中气象要素的精准预报和科研业务中气象资料的准确利用提供保障,为卢氏站气象资料序列延续和均一化处理提供依据。  相似文献   

16.
The advantage of blade-offset rotary vane compressor is analyzed, and its kinematic model is established through simplifying the vane motion to the circle center movement of the main vane arc by using equidistant curve envelope principle. Then, the relationship between the displacement, velocity, acceleration of blade and the angle of rotor is obtained. Finally, based on the theory obtained, the simulation is also carried out. Results show this method can avoid complex process for finding the contact point, which meanwhile has good solving accuracy. Because of the differences on kinematic characteristics, the blade kinematic analysis for blade-cardiac cannot be simply used for the blade-offset one, and the kinematic and dynamic characteristics of cylinder profile cannot be shown by the simplified analysis. However, the scientific theory calculation method for the kinematic analysis of blade-offset rotary vane compressor put forward provides a reliable theoretical basis for the innovation of multi-stage combination cylinder profile with high volumetric efficiency and compression ratio, and also broadens the design theory of the rotary vane compressor.  相似文献   

17.
During a minibus's practical road driving and engine test rig test for vehicle and engine reliability, the phenomenon of generator compressor bracket fracture appears and leads the generator compressor crankshaft belt rupture. It seriously affects the vehicle's operation performance. The article carries through engine test rig test and analysis, using frequency and spectrum technology to identify the bad vibration source combining FEA. It also researches vibration's occurrence, formation, propaganda and fracture mechanism. Based on this, the authors put forward countermeasure, which improves the dynamic characteristic of the system, decreases the vibration intensity and avoides the fracture of bracket and belt.  相似文献   

18.
为深入了解长江源径流的演变特征和变化趋势,笔者以长江源为研究区,采用集中度、集中期、线性倾向估计、Mann-Kendall突变检验、模比系数差积曲线,研究了长江源区径流的年内、年际、年代际趋势性变化,突变点检测和丰枯周期性。结果显示:长江源区1956—2012年径流量总体呈显著增加趋势,上游径流量年际变化较下游剧烈。长江源径流集中度主要集中在55%~85%,上游集中度高于下游。集中期主要分布在7月下旬—8月上旬且有推后趋势。沱沱河站径流主要受降水和冰雪融水补给,直门达站径流主要受降水、冰雪融水和地下水补给。21世纪以来,长江源径流进入丰水期,直门达站比多年平均增加19.3%,上游沱沱河站增加更为明显,达53.8%。沱沱河站年径流量突变点发生在2005年。直门达站年径流量突变点发生在1961、1968、2008年。1956—2012年沱沱河站有1个完整的丰平枯周期,直门达站有3个丰平枯周期。  相似文献   

19.
摘要:本文针对北京水源地密云库北区域生物质能源利用的原料供应问题,采用实地调研、模型核算及投资项目投资估算的方法,以西庄子生物质气化站为典型案例,核算了该生物质气化站以果园林木废弃物为原料的平均资源收集半径为5.6公里,以及考虑收集费用等经济约束条件下合理资源收集半径为6.4,并据此,提出库北三镇的应建设林木废弃物生物质气化站的合理数量,为政府部门提供决策服务。  相似文献   

20.
2013年多模式对抚顺降水预报的检验   总被引:1,自引:1,他引:0  
为了提高抚顺地区晴雨预报准确率,减少空报和漏报的发生,对2013年1—8月德国数值模式和日本数值模式降水预报产品的48h降水量减去24h降水量作为24h降水预报量进行晴雨预报准确率、降水评分、空报率和漏报率分析。结果表明:德国模式降水预报产品的2762、2863、2763站点和日本模式降水预报产品的3351、3452、3352站点的降水预报值与抚顺、清原、新宾的降水有很好的对应关系;德国和日本模式降水预报产品对抚顺24h降水评分相同,日本模式空报率高,德国模式漏报率高;德国模式晴雨预报准确率高于日本模式;在抚顺的日常24h预报中,德国模式降水预报产品更值得关注。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号