变工况

To all project practicality, the introduction is given to the operational characteristics, the methods for calculation and the researching actuality of the tail tunnels with sloping ceiling underground hydropower stations the Three Gorges. This paper has discussed in detail the characteristic method being the same with the compressive flow and the Priessmann solution being the same with the free-surface-pressure flow. And how to deal with boundary conditions has been expatiated. Also hydraulic transient process of tremendous load fluctuation in the tail tunnels with sloping ceiling has been numerical simulated and the Fortran program for numerical simulation has been given. The paper gain the maximal press for tail end of the shell, the maximal rising rate of rotational speed of generating set, the maximal vacuum degree for inlet of the tail tunnels and so on under 11 kinds conditions of tremendous load fluctuation. These conditions include the design conditions, the check conditions and the superposition conditions. Finally, the computing results have been analyzed and summarized. The end chapter is the general comment of the whole-length content and the describing of the intending view of researching.

本文以三峡右岸地下电站尾水洞设计为背景，从工程实际出发，阐述了变顶高尾水洞的工作特性、使用范围及其研究现状；详细论述了适用有压流的特征线法、适用明满交替流的普里斯曼解法等数学模型；边界条件的给定和明满交替流的计算方法；用Fonran语言编制了数值计算程序，对三峡右岸地下电站变顶高尾水洞的大波动工况进行了数值模拟，分别得出了在设计工况、校核工况和叠加工况下蜗壳末端最大压力上升值、机组最大转速上升值和尾水管进口最大真空度等重要参数；对数值计算结果进行了详细分析并得出了有价值的结论；最后展望了今后水电站变顶高尾水洞的研究方向。

The article covers the full research on such aspects as mathematic description, numerical analysis method and their practical applications. The diphase heating surface is divided into a hot water section, a evaporation section and a micro overheat section , the problems of model switching are avoided successfully between subcritical and supercritical working condition in the model of The diphase heating surface, and the model can be used for between subcritical and supercritical working condition without causing the model stiff infinity prick up problem. The mathematical model and dynamic characteristic account is unified and predigested for the diphase heating surface of once—through boiler under subcritical and supercritical pressure, and propose that the working conditions at phase change point could be used as divide criterion between water region and steam region under supercritical pressure, the problems are solved successfully between water and steam phase change point under supercritical pressure.

本文在过程的数学描述、数值分析以及实际应用等方面进行了系统的研究分析，将双相受热面统一划分为热水段、蒸发段和微过热段三段，所建立的双相受热面模型不但成功地避免了超临界工况与亚临界工况间的模型切换，而且消除了由区段划分欠妥所引起的模型刚性无限加剧的问题，统一并简化了超临界及亚临界压力下直流锅炉双相区段的数学模型和动态特性计算，而且提出了利用相变点工况作为超临界压力下划分汽水区域的标准，解决了超临界压力下水与蒸汽的相变点问题。

The results indicate that in the synchronizing condition the MRF is unyielded, every point of MRF in the flow field has the same angular velocity. Under the slipping condition, with the increase of magnetic field or the decrease of slip speed, MRF may transfer from whole yield to partial yield. When the MRF wholly yields, the angular velocity of MRF increases nonlinearly with its radius, the non-linear distribution becomes more obvious as the magnetic intensity in the working gap increases. When the MRF partially yields, the yield region expands with the decrease of magnetic intensity or the increase of slip speed and the unyield region always reaches the driven rotor. The transfer torque of MRTD increases with the increase of the external magnetic field, but the transfer torque maintains a constant value approximately with the variation of slip speed at the same magnetic intensity.

研究结果表明，在同步工况下，传动装置流场中磁流变液未屈服，各点角速度相同；在滑差工况下，随外加磁场的增大和滑差转速的减小，磁流变液逐渐从完全屈服向部分屈服转变；磁流变液完全屈服时，磁流变液角速度随半径呈非线性增加，工作间隙中磁场越强，流场的非线性分布越明显；磁流变液部分屈服时屈服区域随外加磁场的增大而减小，随滑差转速的增大而增大，未屈服区与主动转子相连；稳态下磁流变传动装置传递的转矩随外加磁场的增加而近似呈线性增大，但在相同外加磁场下，传递转矩基本不随滑差转速改变而改变，表现出良好的恒转矩特性。

Bellows Gate Valves However, in large differential pressure operating conditions, evaporation pressure has eased, the evaporator load requirements of the fluid volume decreased, but the actual situation the contrary, in the suction superheat unchanged, due to evaporation pressure has eased, the evaporator outlet pressure be reduced accordingly, pressure changes above and below the diaphragm, causing the main valve opening increases for increased fluid; but in a small pressure operating conditions, evaporation pressure rise, evaporator load demand for fluid volume increased, but the reality is that in the suction gas superheat unchanged, due to evaporation pressure rise, a corresponding increase in the evaporator outlet pressure, pressure difference above and below the diaphragm smaller, so that the main valve opening decreased for the reduction of liquid volume; in variable load is all about.

但在大压差工况下，蒸发压力降低，蒸发器负荷需求的液量减少，但实际情况相反，在吸气过热度不变的情况下，由于蒸发压力降低，蒸发器出口压力相应降低，膜片上下的压差变大，使主阀开度增大，供液量增加；但在小压差工况下，蒸发压力上升，蒸发器负荷需求的液量增多，但实际情况是在吸气过热度不变的情况下，由于蒸发压力上升，蒸发器出口压力相应提高，膜片上下的压差变小，使主阀开度减小，供液量减少；在变负荷下亦如此。

A method is supplied to decide normal states of regenerative heater under variable steam conditions, and to diagnose troubles of regenerative heater; Frugal formula can be used to calculate the pipe pressure loses of extractive steams, and to diagnose problems of extractive steam pipes.

提出了回热加热器正常状态的确定方法，可用此方法判断加热器运行状态是否正常；弗留格尔公式可用于确定变工况下抽汽管道压损值和诊断抽汽管道的故障。

In the thesis, efficiency calculation of the power plant feed pump driving steam turbine in the unit operation is mainly analyzed, concerning the variant working condition economical analysis of this turbine.

论文围绕电站给水泵汽轮机变工况经济性分析这一课题，着重分析该汽轮机在机组运行中效率计算的问题。

Using the theory of steam turbine's varying conditions, research thermodynamic calculation on steam turbine for feed water pump, and integrated to the monitoring state and maintenance assist support system of feed pump for YuanBaoShan Power Plant.

应用汽轮机变工况理论，开发给水泵汽轮机性能计算模块，并集成到元宝山电厂给水泵组状态监测与维修辅助支持系统。

By computational fluid dynamics technique, the aerodynamic performances of different types of twisted blades are numerically investigated in the design and on the off-design operating conditions. The aerodynamic performances of the enlarged model fans in self-stimulated domain are compared with that of the micro-scale fans in non-self-stimulated domain.

通过计算流体动力学技术，对利用该方法所设计的各种形式扭叶片的气动性能及其变工况时的气动特点进行了数值研究，并比较了工作于自模区与非自模区风扇的气动性能差异。

The double sublimation front model was simulated numerically with variable time-step finite volume method. This study mainly concentrates on the influences of control parameters, such as loss factor, initial saturation and electric field strength, on microwave freeze-drying. A comparison of the numerical results was done for different porous structure form as well.

对包括电介质损耗系数、物料的初始饱和度及电场强度等在内的变工况下非饱和含湿多孔介质微波冷冻干燥过程进行了计算，分析了各个参数对干燥过程的不同影响，同时对不同坐标系下的数值计算结果进行了比较。

ABSTRACT The Humid Air Turbine cycle has been identified as a promising way of generating electric power at high efficiency and low c...

湿空气透平循环具有高效率、高比功、变工况性能好、系统简单等优点，是燃气轮机研究中的一个主要课题。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。