西藏拉洛水利枢纽沥青混凝土骨料质量评价及料场比选

沥青混凝土心墙是土石坝的重要结构,骨料、填料等原材料质量对心墙抗渗性、耐久性及适应变形的能力具有决定性影响。以位于西藏自治区日喀则市的拉洛水利枢纽工程为例,初拟2处沥青混凝土人工骨料石料场以资比选,进行了各项质量参数的试验检测,综合考虑各种因素后选定了运距虽然相对较远但质量更好的卡贡灰岩石料场作为料源,确保高原、高寒、高海拔地区沥青混凝土心墙坝的安全。同时,分析、讨论了沥青混凝土用人工骨料原材料岩石质量评价时应注意的若干问题,并提出了解决问题的意见和建议,可供下一步修订相关标准时参考。     

超高压水力割缝强化抽采瓦斯技术研究

水力割缝是一种重要的强化瓦斯抽采增透技术,现已开始在低透气性突出煤层应用。为了进一步考察其实际效果,选取新集二矿1煤组220112工作面底抽巷实施了100 MPa超高压水力割缝试验。试验结果表明:割缝后,瓦斯抽采纯量平均0.77 m3/min,是未割缝钻孔的瓦斯抽采纯量(0.34 m~3/min)的2.26倍;1煤层组瓦斯抽采钻孔抽采30、60天的抽采有效半径为5 m、7.5 m,极限抽采半径为8 m,相比水力冲孔、未割缝钻孔抽采有效半径显著增加,超高压水力割缝强化抽采瓦斯技术具有广泛的应用前景。     

Design of hydraulic shift mechanism for AMT vehicles based on the collaborative optimization method

Based on multidisciplinary design optimization (MDO), a new design method is put forward for hydraulic shift mechanism of heavy-duty vehicle automated manual transmission (AMT). Taking a shift cylinder for example, the collaborative optimization (CO) method for the design problem of a cylinder is devided into one system level design optimization problem and three subsystem level design optimization problems. The system level is an economic model and the subsystem level is mechanics, kinetics, and a reliability model. Application of the multidisciplinary design optimization software iSIGHT modeling and solving, optimal solution of the shifting cylinder CO model is obtained. According to the optimal solution, oil cylinders are machined out and installed on the gearbox of an AMT system for the bench cycle shift test. The results show that the output force and action speed of the optimized mechanism can meet requirements very well. In addition, the optimized mechanism has a better performance compared to the structure of the traditional design method, which indicates that the CO method can optimize the design of hydraulic transmission.     

Analysis on the gear-shifting schedule of hydraulic automatic transmission

With an advanced foreign hydraulic automatic transmission as the objective, an analytical method for the gear-shifting schedule is proposed. First the demanded maximum gradient of test is estimated. Then a test scheme and analytical procedure is formulated by initial test and hypothetical shift parameters. Finally through gear-shifting tests under different road conditions, load, accelerator pedal position limitation, throttle opening and output shaft speed are found to be the gear-shifting parameters. Under a common road condition, the gear-shifting schedule is a double-parameter schedule. Based on the driver''s demands on braking and dynamic performance, different shift schedules are made under downhill, uphill and quick releasing acceleration pedal conditions. The operation criteria of down-shift schedule on abrupt grade are proposed.     

沥青混凝土心墙土石坝水力劈裂计算分析

分析了土石坝水力劈裂原理,针对新疆吐鲁番二塘沟沥青混凝土心墙土石坝,选取河床部位最大断面为典型断面,采用有限元法对其进行水力劈裂计算分析,得出:该土石坝心墙任一高程处的中主应力都小于竖向应力,且中主应力和竖向应力都大于水压力。因此,该坝的心墙不会发生水力劈裂。     

丹江生态流量计算研究

丹江是汉江的重要支流,水力资源较为丰富,在河南省境内丹江干流上建有两座小型水电站,水力发电效益较好,但对下游河道生态造成了不利影响。本文根据实测流量资料,采用水文学方法进行河道生态流量计算,提出丹江干流水电站下泄生态流量要求及保障措施,为丹江河南段的水生态保护提供借鉴和参考。     

CFD在调压室设计计算中的可行性研究

采用C FD方法对简单调压室和阻抗式调压室进行数值模拟,计算出不同分流比下,调压室的阻力系数值,将模拟结果同文献中的试验值进行对比分析。结果表明,模拟曲线和试验曲线的趋势基本一致,并且模拟数值和试验数值高度吻合,该方法可应用在调压室的阻力系数研究中。在此基础之上,该方法应用在实际电站调压室的模拟中,并通过水力过渡过程的计算,验证了该结果的准确性。最后得出结论, C FD方法可应用于调压室的设计计算。     

JZ-3型水轮机修复机械手路径轨迹规划

针对水轮机修复机械手在水轮机转轮的异性叶片曲面上焊接的路径轨迹规划问题,在概述了水轮机修复专用机械手运动方程的基础上,论述了经过修订的两种笛卡尔空间路径轨迹规划算法.为使规划的路径轨迹准确通过补焊位置而减小误差,同时尽可能使工作路径涵盖绝大部分的水轮机叶片曲面,提出了任意四边形内多焊道等宽路径轨迹规划的概念、算法和相应步骤.编程和仿真显示此方法可用于异形曲面的路径轨迹规划,并使焊道涵盖90%左右的水轮机叶片表面.     

浅谈生态水利工程建设

随着经济社会的不断发展,环境问题日益突出,在进行水利工程建设时必须正确处理好工程建设与环境保护的关系,在此情形下生态水利工程建设应运而生。文中通过介绍生态水利工程的基本概念,分析了生态水利工程对环境的影响,在此基础上提出了进行生态水利工程建设时所应遵循的几个原则。     

顶升调正纠偏法在储油罐安装过程中的应用

介绍了立式钢制储油罐倒装法施工过程中,采用整体液压顶升油罐后注入沥青砂的调正纠偏具体做法,解决了因底板边缘板局部在罐自身重力作用下出现凸凹变形,导致底层壁板与罐底板角焊缝无法组对焊接的问题,对解决大型储油罐安装过程中的此类问题有一定的指导意义.