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1.
分别对 3种工况下连续重整加热炉中特定复杂燃烧器和多燃烧器组合的燃烧状况进行了数值模拟 ,建立了连续重整加热炉内多火焰组合燃烧数学模型 ,对炉膛和瓦斯燃烧器进行了网格划分。结果表明 ,在多个瓦斯燃烧器射流之间存在相互干涉现象 ,对于有不同数量燃烧器的加热炉 ,炉膛内流场和温度场以及组分分布均存在差异。重力对于炉膛内的流场、组分分布、温度分布都有较大的影响 ,对这种影响给出了合理的预测结果。  相似文献   

2.
连续重整加热炉内多火焰组合燃烧的数值模拟   总被引:1,自引:0,他引:1  
分别对3种工况下连续重整加热炉中特定复杂燃烧器和多燃烧器组合的燃烧状况进行了数值模拟.建立了连续重整加热炉内多火焰组合燃烧数学模型,对炉膛和瓦斯燃烧器进行了网格划分。结果表明,在多个瓦斯燃烧器射流之间存在相互干涉现象,对于有不同数量燃烧器的加热炉,炉膛内流场和温度场以及组分分布均存在差异。重力对于炉膛内的流场、组分分布、温度分布都有较大的影响,对这种影响给出了合理的预测结果。  相似文献   

3.
对传统燃烧方式下和应用富氧燃烧技术(O2/CO2燃烧技术)时电厂天然气锅炉内的燃烧特性进行数值模拟研究.结果表明随着氧气浓度的增大,整个炉膛的高温区分布趋于集中,烟气温度增加,火焰分布更为集中,充满度也越来越差.当氧气浓度为25%时,炉膛内的温度分布和烟气辐射特性与传统燃烧方式下最接近.当氧气浓度由21%上升到40%时,炉膛内烟气温度得到较大幅度的提高,燃烧器所在截面温度上升300 K以上,火焰充满度变差.  相似文献   

4.
针对生物质成型燃料燃烧特性及现有生物质锅炉炉膛温度高、排烟温度较高、热损失大等问题,通过优化设计和试验研制出适合生物质成型燃料燃烧的专用链条锅炉,锅炉为单锅筒纵置式布置,采用倒U型后拱炉膛结构及独特的二次风设计,锅筒内布置高效螺纹烟管.试验得出,锅炉的燃烧效率达94.88%,热效率达80.07%,锅炉排烟中CO、NOx、SO2、烟尘含量分别为395×10-6、147×10-6、52×10-6、28.9 mg/m3,表明锅炉的燃烧效率、热效率较高,锅炉消烟除尘性能较好,排烟中的烟尘、氮氧化物及SO2含量低,符合国家锅炉的污染物排放标准要求.  相似文献   

5.
对矩形截面的方箱形管式加热炉提出了一种新的底部向上旋流燃烧方式,这种旋流可由多个倾斜向上的喷口射流形成,且涡旋可不止一个.在模拟试验炉上对传统底部向上直流燃烧方式和新的旋流燃烧方式进行了热态对比试验.结果表明,由于旋流的作用,炉膛下部燃烧和传热得到强化,出口烟温下降,炉膛热效率显著提高.  相似文献   

6.
本文采用热态试验和数学模拟的方法,研究了金属板坯在快速冲击加热炉内被射流冲击加热时的内外部传热机构。结果表明炉内的热交换主要集中在炉膛下部并以对流换热为主,在传给金属的热量中,对流换热量可高达80%。研究还发现了冲击加热后期出现金属向炉膛的反向辐射这一新的传热特征,反向辐射出现的时间主要取决于对流传热率的大小。  相似文献   

7.
针对某型煤气混烧锅炉运行中由于煤质波动引起的过/再热器超温、飞灰可燃物含量及排烟温度过高等问题,进行不同煤质下高炉煤气掺烧数值模拟,并进行燃烧调整试验.结果表明,掺烧高炉煤气后炉内温度显著降低,烟气量增加,炉膛出口烟温升高,排烟温度升高,锅炉热效率降低.锅炉燃用贫瘦煤时,炉膛整体温度较低,掺烧高炉煤气不利于煤粉的燃尽,飞灰可燃物含量整体偏高,同时排烟温度较高,锅炉整体热效率较低.煤气混烧锅炉运行时应加强燃料管理,减小煤质波动,并根据煤质情况合理调整高炉煤气掺烧量.  相似文献   

8.
步进式加热炉内流动与传热过程的数值模拟   总被引:7,自引:0,他引:7  
建立了步进式加热炉内流动、燃烧和传热的数学模型.湍流模型采用κ-ε双方程模型,辐射换热计算采用六通量法,气相燃烧采用修正EBU模型,流场计算采用Simpler算法.采用上述模型与算法得到了炉内详细合理的温度、速度和浓度分布.  相似文献   

9.
介绍三排料蓄热式燃烧技术在临钢生产线的应用,新建三排料蓄热式加热炉空气煤气的预热温度,提高低热植煤气的燃烧温度,降低排烟温度三排料蓄热式有效的提高加热炉的产量。  相似文献   

10.
空气预热器技术应用于乙烯裂解炉的计算流体力学模拟   总被引:1,自引:0,他引:1  
为了深入了解裂解炉内的辐射及燃烧情况,并分析空气预热器的效果和影响,采用计算流体力学软件Fluent对KBR型乙烯裂解炉炉膛辐射段的流动、燃烧反应及辐射传热进行了三维模拟。在得到炉膛中温度场、主要组分质量分数分布等情况的基础上,对裂解炉安装空气预热器、预热进入炉膛底部燃烧器的空气的情况进行了研究。分析得出投用空气预热器的节能效果及对炉膛运行的影响。模拟结果与工业实际符合较好,为空气预热器的应用提供了理论上的参考。  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.
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   

13.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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   

16.
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   

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.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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