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1.
利用自制水合物实验装置研究了温度为15.3~25.4℃、压力为0.41~24.72 MPa条件下4组煤-表面活性剂溶液体系中瓦斯水合物的生成过程,得到水合物生成的热力学参数,运用气体水合物生成速率理论对实验数据进行了计算.结果表明:表面活性剂的加入促进了水合物的生长,水合物的生成速度与表面活性剂的种类、浓度有关,不同种类的表面活性剂溶液虽然其浓度相同,但诱导时间和生成速度均有很大差异.对煤-气界面水合物不规则生长的现象进行了分析,认为表面活性剂的存在使煤体表面产生了促进水合物生成的吸附层.  相似文献   

2.
为了揭示表面活性剂在瓦斯水合物生成过程的促进作用规律,利用可视化水合物实验设备,研究了5组表面活性剂溶液体系(T40,1.0×10-3 mol·L-1;T80,1.0×10-3 mol·L-1;T40/T80,1.0×10-3 mol·L-1;SDS,10.0×10-3 mol·L-1;SDBS,2.0×10-3 mol·L-1)中瓦斯水合物的生成过程,运用直接观测法测定了水合物生长的广义诱导时间,结合建立的水合物诱导时间模型对实验数据进行了计算和分析.结果表明:表面活性剂的加入降低了溶液的表面张力,促进了烷烃类气体溶解,加快了晶核形成过程,缩短了水合物生成的诱导时间.该成果对运用水合物技术储运瓦斯具有一定理论价值.  相似文献   

3.
为防治煤矿瓦斯突出事故和分离低浓度瓦斯,研究了瓦斯水合机理,设计了可视化实验装置及3组含煤表面活性剂溶液系统(T40、T80、T40/T80),依据瓦斯水合物的生成过程以及3种组分瓦斯气样在不同实验体系中水合化分离情况,采用色谱分析法,计算了CH4分离提纯浓度。结果表明:瓦斯气体在含煤表面活性剂溶液中生成较快;存在记忆效应的条件下,诱导时间可缩短至47min,生成速率可达2.33×10-5m3/h;CH4的体积分数分别为26%、39.8%和58.98%的三种气样,经一级瓦斯水合化分离后,CH4的体积分数可提高到40.6%、60.41%和80.41%。研究结果证实了利用水合机理防治煤矿瓦斯事故和分离低浓度瓦斯技术的可行性。  相似文献   

4.
水合物分离二氧化碳气体的研究   总被引:7,自引:0,他引:7  
气体水合物是在一定的温度和压力下由气体分子填充水分子产生的晶格而形成的一种笼形晶体.这种水结晶体具有高密度的特性使其成为诸多基于气体水合物应用技术的基础.利用气体水合物生成的原理,将空气中的二氧化碳分离出来,并以气体水合物的形式储存在海洋深处.对二氧化碳气体水合物的生成过程和表面活性剂的促进作用进行了实验研究.选取十二烷基硫酸钠(SDS)、十二烷基苯磺酸钠(SDBS)、对甲苯磺酸(p-TSA)三种表面活性剂进行了二氧化碳气体水合物生成的促进研究,确定了促进气体水合物生成的机理与途径.结果表明:三种表面活性剂在一定的程度上都能缩短气体水合物生成的诱导时间,提高了气体水合物的生成速率.  相似文献   

5.
以辛烷、十二烷或十六烷为油相,非离子表面活性剂Tween80和Span80按1:1质量比复配的复合型表面活性剂为乳化剂,PEG-400为助乳化剂制备高分散的油包水型(W/O)微乳,并在其静态体系中生成甲烷水合物,把它和纯水体系以及表面活性剂体系(含等量的乳化剂)进行了对比.结果表明:在微乳中甲烷水合物的诱导时间缩短,生成速率和耗气量明显增加,生成的水合物成粒状,含水率低.另外,选择油相时应选取不生成水合物,在水中溶解度小而且对甲烷溶解度尽量大的有机溶剂,并对微乳液中甲烷水合物的生成机理进行了探讨.  相似文献   

6.
瓦斯气体在煤储层中的赋存状态主要有游离态、吸附态和溶解态.从瓦斯原始地质赋存条件分析了瓦斯水合物形成必需的物质条件和热力学条件,提出了其赋存的一个新的状态--瓦斯水合物态.利用水合物实验设备对合成瓦斯在2组含煤溶液体系中的生成过程进行研究,得到了瓦斯水合物生成的诱导时间、生成速度及生成时的热力学参数.将瓦斯赋存条件同实验模拟结果进行比较,结果表明:在中高纬度矿区的煤层中有瓦斯水合物自然存在的可能.若瓦斯自然赋存水合物态真实存在,其赋存区煤层应力场、温度场等将发生较大变化,这有利于降低煤矿瓦斯事故的发生频率.  相似文献   

7.
制冷剂水合物蓄冷是实现电网负荷侧调峰、提高空调经济性的一种新型节能技术。提出使用阴离子表面活性剂SDS、非离子型表面活性剂Tween80和Span80、助表面活性剂正丁醇(n-BA)促进静态条件下HCFC-141b水合物生成,基于等容定温法获得5种配比的水合物生成温度曲线,并利用6组平行实验判定水合物平均生成时间、水合体系稳定性;基于图像观察法确定水合物生成位置与质地。结果表明,不同类型表面活性剂均可在不同程度上促进水合物生成,但是水合体系稳定性均较差;其中浓度分别为2 wt%、0.1 wt%、0.1 wt%的Tween80 + Span80 + n-BA体系效果最佳,诱导时间(纯水体系>16 h)缩短至17.5 min,水合物溶液最为均匀,能够实现HCFC-141b水合物快速成核目标。  相似文献   

8.
气体水合物生成特性实验研究   总被引:1,自引:1,他引:0  
实验研究了添加剂对甲烷气体水合物形成过程的影响。发现微量的表面活性剂降低了甲烷气体水合物在静止反应器中形成的诱导时间,并使水合物快速形成和生长,提高了水合物形成过程中的填充密度。阴离子表面活性剂(十二烷基硫酸钠)对水合物生长的促进作用比非离子表面活性剂(烷基多糖苷)强。液态烃环戊烷降低了水合物形成的诱导时间,但环戊烷不能提高水合物的填充密度。  相似文献   

9.
为探寻不同驱动力条件影响瓦斯水合物形成诱导时间的分布规律,利用全透明高压反应釜开展多组分瓦斯混合气(CH_4-CO_2-C_3H_8-N_2-O_2)水合成核动力学实验。基于四种不同驱动力下诱导时间实验结果,结合二次多项式,建立不同组分气体诱导时间和驱动力经验关系。研究发现,同一实验体系中瓦斯水合物形成诱导时间随驱动力增大而缩短;不同浓度瓦斯水合物形成诱导时间分布差异较大。基于偏摩尔吉布斯自由能随驱动力变化规律,初步探讨驱动力对多组分瓦斯水合物成核过程影响机理。分析认为:在一定范围内驱动力对瓦斯水合物成核过程具有促进作用.而驱动力过高将抑制水合物晶核的形成。  相似文献   

10.
在井下温度合成瓦斯水合物的实验   总被引:1,自引:0,他引:1  
通过实验研究了利用模拟瓦斯气体在井下温度和中高压的条件下合成瓦斯水合物。采用以实验为主,理论分析和计算机模拟相结合的研究方法,目的在于找出压力、温度及表面活性剂对水合物生成过程的影响。在井下温度和中高压的条件下,采用合适的表面活性剂及一定配比成功合成了瓦斯水合物。得出的结论是:表面活性剂在溶液中形成胶束后很大程度上可增加瓦斯气体的溶解度;与压力相比。温度对水合物的影响更重要:在气一液界面先合成的水合物有利于剩余水合物的合成。  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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