共查询到19条相似文献,搜索用时 187 毫秒
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内混式气液雾化喷嘴雾滴粒径的实验研究 总被引:1,自引:0,他引:1
雾滴粒径是衡量喷嘴雾化性能的一个重要指标,为了提高喷嘴的雾化效果,对一种新型的内混式气液雾化喷嘴进行了测试。实验采用4组不同几何结构参数的喷头,研究了气孔直径、气孔数、气液流交角和喷孔直径等喷嘴结构及气压、气液比、混合室压力等工况参数对MMD(质量中值粒径)的影响;并且进一步对实验结果进行了定性和定量分析,得出具有较好雾化性能的喷嘴结构和工况参数,为喷嘴的结构优化和使用提供了依据。 相似文献
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气泡雾化喷嘴流量特性的实验研究 总被引:8,自引:4,他引:4
两种不同结构形式的气泡雾化喷嘴 ,通过实验对其流量特性和混合室内的流型进行了研究。分析实验现象和实验数据发现 :喷嘴混合室内的流型取决于混合室直径 Dc、气液质量流量比ALR、注气孔截面积 A2 及气压 P2 、液压 P1 等参数 ;喷嘴的流量特性则主要受注气孔截面积 A2 、喷嘴出口截面积 A及运行压力等参数影响 ;流量系数 CD 与参数 X呈线性关系。另外 ,通过理论分析推导出喷嘴临界流量公式 :Ml=μAcaρa ( 1 ALR) ALR,且计算值与实验点符合良好。 相似文献
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使用激光相位多普勒分析仪PDA对旋转型气-液雾化喷嘴的雾化特性进行了实验研究。使用水代替油作为被雾化的液体,采用压缩空气作为雾化介质,测量了不同工况下的喷雾特性参数,如:喷雾液滴粒子的索太尔平均直径SMD和粒子速度等。实验测量结果表明,喷嘴在较小的气液比条件下可以达到较好的雾化状态,中心的液滴平均SMD可以达到40μm。随着压力和气液比的增加,雾化水平也随之提高,但是受喷嘴结构的影响很小。本文的研究为喷嘴的实际设计提供了基础依据。 相似文献
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《热能动力工程》2016,31(5)
针对细微颗粒粉尘的治理问题,设计出模拟湿式除尘系统的实验平台,采用清水作为雾化介质,研究了hyd型低压精细雾化除尘喷嘴在孔径为0.4、0.5和0.8 mm时,不同雾化压力参数下流量、雾化角、雾化粒径等雾化特性。采用容积法测量喷嘴流量特性,基于Matlab和Scope Photo软件分析得出喷嘴孔径为0.4、0.5和0.8 mm时雾化角、雾化粒径大小及分布。绘制出雾化特性与压力的关系曲线,并通过Matlab软件对曲线进行拟合得出雾化压力与流量、雾化角和粒径的关系式。结果表明:雾化流量、雾化角与雾化压力成正相关,雾化粒径与雾化压力成反相关;流量特性和雾化粒径受喷嘴孔径的影响较大,孔径越大雾化角受压力的影响减小;实验结果为研究水雾在粉尘治理中的应用提供指导作用。 相似文献
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对于内混式喷嘴,气液存在强烈的混合作用,决定雾化性能的最主要因素是作为雾化剂的高速气体与作为雾化介质的液体进行动量交换的强度。对气动喷嘴的雾化特性进行了数值模拟,对喷嘴内的流动现象进行了分析,得到了一些有益的结论。 相似文献
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An experimental investigation was carried out to find the lifting-pressure performance of a steam-driven jet injector for various configuration parameters. The pressure profiles along the mixing chamber were measured with constant inlet steam and water parameters; the results indicated that the injector had a self-adaptive characteristic and the outlet water mass flow rate had an invariable characteristic. The lifting-pressure coefficient was affected significantly by the area ratio of the secondary nozzle and area ratio of the mixing chamber, and the influences were discussed. Moreover, the pressure distribution characteristic of a supersonic steam jet in water was studied under different steam pressures and water temperatures. The results indicated that the pressure distributions were affected by flow and condensation characteristics that were described by steam pressure and water temperature; the maximum axial pressure ratio was also discussed. Predictions of the distance of the maximum axial pressure by an empirical correlation showed good agreement with the experimental results. 相似文献
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柴油机喷孔内部空化效应的可视化实验研究 总被引:1,自引:0,他引:1
柴油机喷孔内空化现象显著影响燃油雾化质量.针对目前广泛应用的VCO型喷嘴,设计大尺度透明喷嘴稳态实验系统,全面研究了无量纲数、雷诺数、喷嘴射流参数和结构参数对喷嘴内空化过程的影响.结果表明,空化数对空化剧烈程度影响显著,雷诺数对空化剧烈程度影响小于空化数;射流参数直接影响流体流动状态,增大入口压力、减小出口压力和针阀升程能使喷孔内的空化现象显著增强;结构参数决定喷孔内流动形式,增大喷孔倾角、直径和长径比,采用入口圆角等措施会抑制空化的产生. 相似文献
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DaoTong Chong JunJie Yan GeSheng Wu JiPing Liu 《Applied Thermal Engineering》2009,29(14-15):2799-2807
The supersonic ejector was introduced into boosting the production of low pressure natural gas wells. The energy of high pressure gas wells, which was usually wasted through choke valves, was used as its power supply to boost the low gas production. The operating performance of natural gas ejectors was determined not only by the operating parameters but also by the structural parameters. This study focused on the structural optimization and operating performance of natural gas ejectors. The optimal structural parameters were obtained by numerical simulation when the maximum pressure ratio was obtained, and the numerical results were validated by experimental investigation. The numerical results showed that the optimal diameter ratio of mixing tube to primary nozzle throat was 1.6, the optimal length to diameter ratio of mixing tube was 4.0 and the optimal inclination angle of mixing chamber was 28°. The entrainment ratios and pressure ratios from the numerical simulation agreed well with the field experimental data, with the maximum value of pressure ratio up to 60%. The operating performance of the supersonic ejector was also investigated by the field experiment, and the results showed that the induced gas flowrate and entrainment ratio showed nonlinear characteristics with peak values when the motive pressure ranged from 8 MPa to 13 MPa. These experimental results have proved the optimized structural parameters of the supersonic ejector. The investigation will help to the further application in boosting natural gas production of supersonic ejector. 相似文献
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高速直喷柴油机燃烧室形状与喷孔结构匹配规律的三维仿真研究 总被引:1,自引:0,他引:1
对某高速直喷柴油机的燃烧过程进行了多维仿真计算,研究了燃烧室形状和喷孔结构参数之间的匹配规律.通过变参数研究确定了燃烧室形状和喷孔结构参数之间的匹配规律.为了定量描述燃烧过程中燃油雾化、液体蒸发、油气混合的特性,建立了缸内平均湍流混合速率、燃油蒸气质量分数方差的中间特征参数,同时详细分析了不同当量比油气混合气在燃烧过程中的贡献率.从燃烧的宏观和微观角度综合分析了柴油机燃烧室形状与喷孔结构间的耦合作用机制.结果表明,对于所研究的机型,0.64口径比燃烧室匹配10孔喷油器的方案最优:预混过程好,燃烧速度快,后期扩散燃烧阶段过稀和过浓混合气参与燃烧的比例较小且预混与扩散燃烧放热情况差别小,放热情况更均匀. 相似文献
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考虑实际流体性质、混合室阻力和喉部激波现象,采用等压混合模型,根据质量守恒、动量守恒和能量守恒建立中心进气两相喷射器一维模型。以R141b为工质,研究在不同入口参数和混合室截面积变化比(混合室喉部截面积与混合室入口截面积之比)下喷射器的升压特性以及入口参数和混合室截面积变化比对喷射器出口压力和喷射系数的影响。结果表明:在一定工况下,入口主蒸汽压力每增加0.5 MPa,喷射器出口压力提高约0.002 MPa;入口引射液体压力每增加0.1 MPa,出口压力约升高0.6 MPa。相对于入口主蒸汽参数的变化,入口引射液体参数变化对喷射器的升压特性影响更大。另外,随着混合室截面变化比的增大,升压效果下降。在入口引射液体参数为0.1 MPa/299 K和0.2 MPa/321 K的条件下,混合室截面积比分别增至0.6和0.4时,出口处蒸汽不能完全凝结。研究结果适用于大部分工质,为喷射器的设计和运行提供理论指导。 相似文献