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光纤传感用于油田热采的蒸汽干度测量 总被引:1,自引:2,他引:1
折射率调制的光纤传感器可用于测量稠油热采过程中的蒸汽干度测量。当油田的油井中注入高温高压蒸汽时,从井口到井底连续地查明汽液比对节省能源和提高产出率意义重大。由于干蒸汽和水的折射率不同,汽液的比例可以从汽液两相流的折射率响应特性反映出来。研制的测量装置直接对汽液两相流的比例变化产生响应,能够应用于高温高压及狭窄工作空间的输汽环境中。在井深850m,井口蒸汽温度287℃,压力7.49MPa的油田注汽井中进行了测试。测试结果对注汽法采油的井况分析具有一定的参考作用。油田注汽井的测量数据表明,这种干度测量仪可以实现在线、连续的测量工作。 相似文献
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采用基于密度泛函理论的第一性原理计算,系统地研究了BiFeO3的7种不同空间群(R3c,R3m,P4mm,Cm,Pm3m,R3m和R3c)结构及其转变关系.结果表明,铁电相R3c结构是基态,不同结构之间也存在着一定的转变关系,其变化主要包括两种形式,在[111]方向上Bi3+相对FeO6八面体存在一定的位移和FeO6八面体绕[111]极化轴的反铁扭曲旋转.此外,还得出BiFeO3的薄膜结构受到衬底结构的作用会导致其从三方相(R3c)向四方相(P4mm)转变. 相似文献
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中小型低温储罐作为气体工业和天然气工业中的核心设备,在空分装置、中小型LNG装置、LNG储配站及气化站得到广泛应用,其型式的选择关系着装置的造价及运行成本。结合已建部分工程实例,对1500m3、3000m3、5000m3、10000m3球形低温储罐和立式平底圆筒形低温储罐,从结构、材料用量、建造难度及建造周期、基础及运行费用等方面进行了详细对比分析。对比结果为:球形低温储罐在结构承压受力、绝热、基础占地及安全性方面要优于立式平底圆筒形低温储罐;容积较小时,二者的材料成本和运行费用相当;容积较大时,立式平底圆筒形低温储罐各项指标优势明显。结论是:容积在200m3~10000m3之间中小型低温储罐,如考虑工艺要求需带压储存,应选用球形低温储罐;无需带压储存,以1500m3为限,小于者选用球形低温储罐为优,大于者选用立式平底圆筒形低温储罐具有更好的经济性。 相似文献
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合成了水杨醛缩二乙基三胺 (配体 L,2 - [(N- Salicylideneamino) ethyl]amine)与 Cu( )形成的配合物[Cu L(H2 O) ]Cl,通过元素分析、红外光谱、X射线单晶衍射进行了结构分析。配合物为单斜晶系 ,空间群P2 (1) / c,晶体学结构数据 ,a=0 .912 3(5 ) nm,b=1.382 1(7) nm,c=1.0 82 9(5 ) nm,β=10 1.712 (7)°,V=1.336 9(11) nm3 ,Z=4 ,Dcalcd=1.6 0 6 mg/ m3 ,F(0 0 0 ) =6 6 8,R1=0 .0 377,w R2 =0 .10 18。结构分析表明 ,配合物通过氢键形成二聚结构 相似文献
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快速降压下过热液中汽泡的生长 总被引:2,自引:0,他引:2
1前言定压力场下过热液体中汽泡生长已得到深入研究[1-3]。近年来,变压力场下过热液体中汽泡生长问题,引起研究者重视。文献[4-7]研究表明降压对汽泡生长起着重要作用。从理论上看快速降压过程中蒸汽密度随时间变化较大,准确考虑十分困难;过热液处于热力学亚稳平衡状态,因此需用外推法确定物性数据。从实验研究看在快速降压过程中保证时间和空间上同时准确观察汽泡生长,实验技术实施上有一定难度。因此无论从理论上还是实验上对变压场下过热液中汽泡生长研究有待进一步深入。2汽泡生长模型汽泡生长过程中汽液两相化学势差在相变中起着… 相似文献
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激光金属汽化汽离混合区状态参量的稳定性及其影响因素分析 总被引:1,自引:0,他引:1
在汽离混合区激光强度时空修正的基础上,近似求解了流体力学模型下的状态参数,找出了稳定状态参数的共同自洽参量,分析了自洽参量的取值方法,研究了相关参数对自洽参量的影响机制,结果发现:(1)汽离混合区内,状态参量的稳定性可用自洽参量的稳定性来表征;(2)当入射激光强度小于108W.cm-2时,自洽参量随入射激光强度变化相对较快,稳定性差;当激光强度大于108W.cm-2时,自洽参量随入射激光强度变化相对较慢,稳定性高;(3)汽离混合区各处的约化自洽参量随辐照激光的波长成变周期增加的变化,波长越长,约化自洽参量越大;(4)要使自洽参量稳定,纹波较小,宜采取短波激光辐照;(5)当蒸汽压强小于2.7×106Pa时,自洽参量随蒸汽压强成指数递减规律变化;当蒸汽压大于2.7×106Pa时,自洽参量与蒸汽压强之间没有对应关系. 相似文献
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铸铁蒸发器水室结构的参数化有限元分析 总被引:1,自引:1,他引:0
铸铁蒸发器水室常开有大直径管孔,且铸造结构复杂,无法使用常规设计。运用V isual Basic 6.0对AN-SYS进行二次开发,实现了铸铁水室结构的参数化有限元设计。该设计平台有效地提高了设计效率和设计精度,为铸铁蒸发器水室结构的安全评定提供了有效手段。 相似文献
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This study experimentally investigated the thermal performance of a two-phase closed-loop thermosyphon with a thermal resistance model for electronic cooling. The evaporator, rising tube, condenser, and falling tube, which are the four main devices, formed a closed-loop system with water as the working fluid. The experimental parameters were the evaporator surface type, fill ratio of working fluid, and input heating power. The results indicated that the evaporator and condenser thermal resistance decrease with increasing input heating power. The condenser thermal resistance clearly increased with increasing fill ratio. A groove-type evaporator surface with 0.2 mm height and 1 mm width had the best performance, decreasing the evaporator thermal resistance about 15.5% compared to a smooth surface. Correlations for evaporator and condenser thermal resistance were also developed, and their precisions, when compared with the experimental data, were about 9.6 and 11.6%, respectively. Because of the intermittent boiling mechanism at 47% fill ratio with input heating power from 60 to 80 W, the temperature showed obvious oscillations with the smooth evaporator surface. 相似文献
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超临界水驱超稠油提高采收率热物理特性研究 总被引:2,自引:0,他引:2
超稠油资源的高效开发对于提高石油供给和保障我国石油安全意义重大。针对深层超稠油资源由于原始地层压力高、原油黏度大导致常规蒸汽驱无法有效开发的问题,本文提出超临界水驱开发深层超稠油的新思路。本文首先研制了超临界水驱油提高采收率实验平台,研发的管式填砂岩心模型能够模拟岩心升温和驱替的同步过程,然后开展了超临界水驱、蒸汽驱和热水驱对比实验研究,实验结果表明,相对于蒸汽驱,超临界水驱能显著提高采收率并具有更高的热效率,25MPa、400℃超临界水驱鲁克沁超稠油的采收率达到97.07%;获得了超临界水驱过程的温度场和驱替压差变化规律,发现了超临界水超覆现象,与蒸汽超覆相比,超临界水超覆发生晚且持续短,可扩大波及范围,提高采收率。 相似文献
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Thermal decomposition of titanium tetraisopropoxide (TTIP) was carried out in varying reaction atmospheres: nitrogen, oxygen, and nitrogen plus water vapor. The effect of reaction atmosphere on the morphology, size, and crystalline structure of produced TiO2 particles was studied. The reactor used was similar to the microreactor proposed earlier by Park et al. (2001, J. Nanopart. Res., 3, 309–319), but for a modification in the precursor evaporator. The reactor temperature was varied from 300 to 700°C and the TTIP concentration in the evaporator from 1.0 to 7.0 mol%, holding the reactor residence time at 0.7 s. The primary-particle size was in the range 25–250 nm, varying with operating condition. The crystalline structure was amorphous in nitrogen, a mixture of rutile and anatase in nitrogen plus water vapor, and anatase in oxygen atmospheres. In nitrogen, agglomerates composed of very small particles whose individual boundaries are not clearly distinguished were produced. In oxygen, the particles composing an agglomerate became larger and were clearly spherical. As the atmosphere was varied to the nitrogen plus water vapor, the particle size increased further. The variation of primary particle size with reaction atmosphere was discussed in comparison with previous experimental data. 相似文献
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In this paper, a rotational supercavitating evaporator (RSCE) was at first modeled by means of theoretical analysis approach. The geometrical characteristics of supercavity in the modeled RSCE were then studied through numerical simulations. The current research objectives consist in determination of shape of the supercavitator (which in the plane of rotation generates supercavity occupying the most volume between blades), and location of the area suitable for steam extraction by revealing the inner structure of supercavity. Analytical analysis was performed by solving empirical equations for the shape of RSCE, through which an evaluation of two-dimensional relative position of supercavity trailing edge for different shapes of the supercavitator has been realized. Numerical simulation was then carried out, by numerically solving the unsteady Navier-Stokes equations in their conservation form coupled with the Rayleigh-Plesset cavitation and Shear-Stress Transport turbulence models, for verification of the results obtained from empirical equations. Despite unreliable assumption of applicability of empirical equations we have confirmed similarity of the supercavity shapes obtained by both methods for the same RSCE. Therefore, the shape of supercavitator calculated by using empirical equations is acceptable, which provides a simple but reliable approach for design of RSCE. The inner structure of supercavity obtained by numerical simulation has indicated position and parameters for steam extraction openings for further numerical and experimental studies on the performance of RSCE. Practical application of steam or gas extraction is suggested for solving of some problems associated with cavitating pumping of cryogenic liquid. 相似文献
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直膨式太阳能热泵热水器的实验研究 总被引:13,自引:0,他引:13
建立了直膨式太阳能热泵热水器实验样机,该样机采用裸板式太阳能集热器作为蒸发器。在室内模拟光源(0~1000W/m2)下,对该热水器进行了性能测试,得出热水平均加热功率为1.04 kW,热泵平均COP为4.18。通过对实验数据加以整理和分析,得出了热水温度、集热/蒸发板温度、热水加热功率及热泵COP随太阳辐射强度及运行时间的变化规律,并提出了热泵COP的改善措施。 相似文献