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1.
小型沼气发动机性能试验   总被引:1,自引:0,他引:1       下载免费PDF全文
将沼气为燃料的发动机及其性能参数优化作为研究对象,测试分析了试验用沼气的主要成分,建立了小型沼气发动机试验台架,通过试验研究影响沼气发动机性能的因素,分析各因素对沼气发动机起动性、动力性、经济性、排放性的影响,为小型沼气发电机组产业化,积累了有价值的试验数据。  相似文献   

2.
沼气资源丰富.投资不多。大量应用沼气对我国农用发动机能源开辟了一条新途径,具有重要意义.关于纯沼气发动机特别是小马力沼气发动机的资料国内外报道尚少.因而此方面的研制是一项重要的科研任务。  相似文献   

3.
剖析了一种新型发动机——外燃式涡旋发动机的工作原理与结构特点.当其它几何参数不变时,膨胀机比压缩机需要更高的涡圈或更大的基圆半径.提出涡旋式发动机实用化尚存在的问题.  相似文献   

4.
对动力性、经济性、自动闭锁换档特性等方面进行了定量计算和分析.研究了发动机分别使用全程式和两极式调速器时,对闭锁式液力变矩器与发动机共同工作特性的影响.结论是:对公路运输型车辆,宜使用两极式调速器;对越野型车辆,则必须综合考虑多项因素进行选取.  相似文献   

5.
专家计算,1立方米沼气燃烧产生热量相当于0.6升燃油或0.6升天然气。另一种沼气利用燃料箱发电,这一技术利用氢氧的反应,特点是无污染,有很高输出功率。当沼气只用于烧炉灶时,其经济价值很低,大多数生产沼气的农民采用可供生产电力和热能的所谓“集团热电装置”,即由一个汽油机驱动的发电机组生产电,由此产生的余热用于供暖。 沼气用途非常广泛,世界各国已经开始将沼气用作燃料和用于照明。用沼气代替汽油、柴油,发动机器的效果也很好。沼气可以用于农业生产中,如温室保温、烘烤农产品、沼气防蛀、储备粮食、水果保鲜等。沼气也可发电做农机动力,大、中型沼气工程生产的沼气可用来发电、烧锅炉、加工食品、采暖或供给城市居民使用。现在,沼气的应用正在各国广大农村推广,沼气能源的开发利用普及等方面,已经取得了较好成绩,在能源市场中也有着广阔发展空间。  相似文献   

6.
本试验研究旨在探索沼气用于农用动力设备的基本技术途径。本文就发动机及拖拉机的改装等问题进行了探讨,并对试验结果进行了分析。对原发动机调速系统进行了重要改装,在多缸发动机上实现了沼气单调节调速。改装后的拖拉机在沼气—柴油双燃料的驱动下,满负荷工作时,可节油65%以上。  相似文献   

7.
李君  李理光  江华春 《上海交通大学学报》2004,38(7):1161-1163,1169
利用FJ-600瞬态喷射率测量仪,对一种电磁直接驱动式二甲基醚喷射器的喷射特性进行了试验,发现该喷射器在一定的工作范围内,存在着循环供油量随燃料喷射压力减小或喷射背压增大而增大的现象.这一现象将会影响发动机的燃料控制精度,进而影响发动机的燃烧与排放性能.分析确定,出现上述现象的主要原因在于喷射压力和喷射背压直接影响喷射器针阀的起落运动,造成针阀开启截面和实际开启持续期的明显变化,从而导致循环供油量的变化.提高喷射器的电磁驱动力,增加回位弹簧的刚度,将有利于改善此喷射器循环供油量特性.  相似文献   

8.
论述了脉冲式烟雾机燃烧室-喷管结构参数的试验研究,并以脉动燃烧原理和非定常一元可压缩流体的基本理论分析,论证了参数选择的正确性.研究结果表明:脉冲喷气式发动机按声学共振原理工作;燃烧室-喷管,进气单向阀和进油单向阀组成一个自振系统;燃烧室-喷管的结构参数对发动机工作性能有重大影响.  相似文献   

9.
吸气式高超声速技术研究进展   总被引:1,自引:0,他引:1  
系统总结了中国空气动力研究与发展中心在吸气式高超声速技术研究方面取得的主要进展,包括:试验设备、超燃冲压发动机、数值模拟以及机体/推进一体化飞行器。CARDC经过十多年的努力,建成和改造了三种类型的高焓设备:脉冲式燃烧加热风洞、连续式燃烧加热风洞和电弧风洞。开展了多种尺度的超燃冲压发动机的直连式和自由射流式试验,获得了发动机的基本性能及其随油气比、喷孔位置等的变化规律。通过连续式和脉冲式风洞试验结果对比,表明工作时间大于100 ms的脉冲式燃烧设备是开展发动机基本性能研究的经济、高效试验手段。成功研制了三维大规模并行数值模拟软件平台AHL3D并广泛应用于发动机研究。在Φ0.6 m风洞中,完成了1.5 m带动力飞行器试验,获得了发动机工作和不工作状态下的飞行器推阻及升力特性。同时提出了地面试验、CFD和飞行试验三者综合研究分析的重要性。  相似文献   

10.
江苏大学的“一种制动力矩可分挡的永久磁铁式缓速器”技术被授予国家实用新型专利.实用新型以永久磁铁作为磁源的车用缓速器,特指一种制动力矩可分挡的永久磁铁式缓速器.设有一套制动装置,包括一个安装在发动机输出轴上的鼓形转子,一个固定在变速箱上的定子.定子部分主要包括磁铁保持架、固定磁铁支架、活动磁铁支架、永久磁铁及操作机构.磁铁保持架内有两列磁铁,其特征在于每排磁铁有若干组永久磁铁,每一组磁铁由多块极性排列相同的磁铁组成,各组磁铁之间的磁极交替反向排列,各自固定在磁铁支架上.该结构紧凑简单,易于实现.通过改变永久磁铁工作的磁极组数,设置若干制动挡位,使永磁式缓速器根据车辆实际情况的需要提供大小不同的制动力矩.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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