叶片前缘气膜冷却离散孔下游湍流特性试验研究

以NASA发布的燃气轮机叶片为研究对象,风速设定为10 m/s;以热膜风速仪为测量工具,在气膜冷却叶片压力面和吸力面下游指定位置沿不同叶高湍流度进行测量。实验结果表明:随着射流比的增大,压力面和吸力面主射流掺混中心有上移的趋势且掺混中心扰动强弱受当地吹风比影响较大;在压力面叶片型面曲率梯度较大处,沿壁面流动的风速增大导致回流、扰动加强及混合流体的贴壁性变差;吸力面流体近尾流区域在大吹风比下扰动反而减弱;叶片表面的湍流度受到射流比、壁面曲率梯度大小及方向等多方面因素的影响。

某天然气管道土建工程施工管理研究

近些年来,天然气愈加受到人们的关注,因其无色无味无毒、热值高、燃烧稳定以及洁净环保等优势,被广泛应用在人们的生活中,再加上其具备安全可靠、便于运输、价格便宜以及储量丰富等也被应用在相关企业的生产中。然而天然气管道土建公工程施工管理问题就逐渐凸现出来,本文进行相关探讨。

New method for plugging channeling in oil field by nitrogen foam

In order to present a new method for plugging channeling in oil field,the injection modes and validity period of foam system which plugged the formation water layer were studied by means of the experimental model which simulated the real conditions of oil wells existing channeling.Above all,the influence factors including reservoir pressure,permeability,oil saturation and gas-to-liquid ratio were studied through dynamic experiment.Then,in light of the technology characteristics of foam injection in oil field,the comparison between gas-liquid and liquid-gas injection modes was studied.The result shows that the gas-liquid injection mode can ensure the foam injectivity and plugging performance.The plugging validity of nitrogen foam injected into the formation water layer was evaluated in different plugging pressure gradients by the dynamic method which is more reasonable than the static evaluation method in laboratory.The research demonstrates that the plugging validity period of foam decreases with plugging pressure gradient increasing.If the plugging pressure gradient is 0.15 MPa/m,the validity period is 160 h.Finally,a empirical equation and a plate about the plugging validity and the plugging pressure gradient were obtained for forecasting the validity period of foam.

浅谈如何有效降低和控制城市燃气管道工程造价

随着城市天然气应用愈加普遍。当前,燃气管道施工增多,要想在日益激烈的招标竞争中取得优势,施工企业必须要注重控制好工程造价。在保证工程施工质量的同时,最大限度的降低成本。本文将对如何有效降低及控制城市燃气管道工程造价进行论述。