风力提水机性能的改进

在同样叶轮直径,同样运行条件下可对变行程与不变行程风力提水机进行了对比实验,实验结果表明,在低风速度下,可变行程风力提水机的性能与不变行风力提水机相比差别不大;但在高风速下,可变行程风力提水机具有提水量大,效率高,泵运行转速稳定等优点,极具开发利用价值。     

选用低转速水泵节约电能

水泵是机械循环热水采暖的心脏,是直接影响采暖经济效果的主要因素之一。目前,我国低温热水采暖设计多选用 B 型水泵。转速为2900r/min、大流量、高扬程、大容量电机,造成很大浪费。若选用低转速(1450r/min、960r/min、720r/min)且流量、扬程适合设计要求,需要电机容量就小,这样的水泵则可节约电力。水泵的流量 G(m~3/h)、扬程 H(米)、电机     

600MW机组凝泵变频改造后振动模态治理研究

某电厂3号机凝结水泵在2008年检修时进行了凝结水泵的变频改造,在改造后的变频调试中,凝结水泵3A在850 r/min到900 r/min这个转速范围内振动明显,严重影响了机组安全生产运行。用ANSYS软件模态分析计算做理论指导,通过加固强化基座桶体刚度来提高桶体的固有频率而避开共振峰转速,以使泵在变频转速范围内能够避开基座筒体的固有频率,从而解决变频运行中振动值过大的问题,达到预期的节能效果。     

一起东风4B型机车柴油机"飞车"原因浅析

1 事故概况 1998年12月8日,我段东风4B3372号机车担当沪杭线货物牵引任务,当列车运行至七宝站时,柴油机突然停机,此时柴油机转速为920r/min.副司机进动力室检查,发现极限调速器动作,抬复原手柄后起机,提转速到860r/min,柴油机极限调速器又动作,复原后再起机.由于一时紧张,连续两次起机均未成功.司机用筷子顶死DLS强迫起机,当转速上升至800r/min时,极限调速器再次动作,司机也未仔细检查,抬复原手柄继续起机.起机后柴油机转速直升至1400r/min,发生"飞车",造成机破.     

风电提水系统及参数匹配

分析了小型风电提水系统的主要构成及原理,研究了风力发电机与潜水电泵参数的优化匹配问题,提出了用单片机通过逆变器进行控制的方法.以1 000 W风力发电机和550 W水泵为例进行了试验,其结果基本能满足风力机和水泵的匹配要求.     

小型风力提水机的低实度风轮设计及其数值模拟

针对传统风力提水机实度大、风能利用率低的缺点,采用NACA4412航空翼型及叶素动量理论对小型风力提水机叶片的气动外形进行设计,采用6叶片风轮形式,引入修正因子,并根据工程实际优化了叶片的弦长及安装角,并采用CFD方法对风轮进行数值模拟。结果表明,设计的风力提水机在2.8 m/s的微风下可起动,在额定工况下风能利用系数达0.43,叶片具有很好的三维流动特性,风能利用系数高,降低了传统风力提水机风轮的实度,扩大了风能的利用范围。研究结果对风力提水机的改进设计有指导意义。     

Wartsila公司推出RT-flex50 D系列发动机

RT-flex50 D系列发动机在维持转速124 r/min不变的前提下,将最大持续输出功率提高了5.1%,即从1 660 kW/cyl提高到1 745 kW/cyl.RT-flex50 D系列为直列机5缸到8缸机,功率覆盖6 100～13 960 kW,转速99～124 r/min.     

风力提水在制盐业和对虾养殖业中的经济效益

1987年4月中国农机院在射阳盐场安排了四台FDG—5型风力提水机用于海盐生产,当地提水扬程为0.6～1.3米,在生产运行中,经反复测试表明:在3～4级风时,机组流量为80～110米~3/时,风力机组起动风速仅为2.5米/秒。抗大风能力强,去年7号台风袭击射阳盐场时,18米/秒以上大风持续数小时之久,FDG—5型风力提水机照常工作完好无损。根据五个月的生产运行分析:在正常天气下,每台FDG—5型风力提水机可分22公顷盐池提供用水,相当一台5.5千瓦的电泵,每年可节电5000度。采用风力提水机     

风力提水机可变行程之实现途径

描述了可变行程风力提水机与普通风力提水机相比的优点,探讨了可变行程的具体实现及控制方法,指出了可变行程风力提水存在的一些问题及今后的改进方向。     

FS—2.5风力提水机组 风力提水贮水防冻装置简介

现将内蒙锡盟风能利用研究所研制的FS—2.5型风力提水机组和风力提水贮水防冻装置为例介绍如下。一、FS～2.5型风力提水机组该机组由风力机和水泵两部分组成。风力机由风轮、机头、尾翼、刹车机构,塔架以及用户自己制造的井盘、地锚和贮水罐(或水池)等组成(见     

驱动热泵的垂直轴风力机风轮气动特性数值分析

根据风能热泵系统的工作环境及匹配特性,针对给定供热面积的系统各参数选取方法以及垂直轴风力机风轮设计进行了探讨,在此基础上初步完成了额定功率为300 W的风轮设计,并利用二维数值模拟方法对不同叶尖速比下的性能曲线进行计算,分析得到了额定风速9.00 m/s时,驱动压缩机的最佳风轮转速为350~375r/min。结果表明,300 W垂直轴风力机的输出特性可满足风能热泵机组的工作要求,该数值分析结果可为风能供热技术的应用示范提供理论支撑。     

液粘调速装置在节能减排中的应用

针对水泵风机采用恒速节流调节运行时存在浪费大量电能的问题,吉林油田水厂选用液粘调速装置改造水泵机组后,通过改变水泵和风机转速调整水量、风量,使轴功率大幅度降低,节约大量电能,经济效益可观。     

加装后缘小翼的垂直轴风力机输出特性研究

为了研究H型垂直轴风力机后缘加装小翼的输出特性变化规律,文章以NACA0012翼型叶片为例,采用风洞试验与数值模拟的方法,对加装后缘小翼的风力机进行了研究。模拟结果表明,加装后缘小翼的风力机的单叶片扭矩系数及功率性能要优于未加装小翼的风力机,整体功率较未加装小翼的风力机略有提升。风洞实验结果表明:加装后缘小翼可以提高风力机的最大输出功率,其中径长比对于加装小翼的垂直轴风力机功率提升的影响较大;当转速小于300 r/min时,安装径长比为0.6的后缘小翼的风力机输出功率最高;当转速超过300 r/min时,径长比为0.4的后缘小翼的风力机输出功率最高。     

高速铁路上空安装光伏系统的节能潜力研究

高速铁路的运营需要大量电力供给,为缓解铁路电网压力,减少能源消耗,提出一种在高速铁路上方架设光伏组件的发电系统;对上述系统进行相关计算,量化全国设计时速超过200 km/h高速铁路线路的光伏发电潜力。研究结果表明,在中国太阳年辐射量大于1200 kWh/m²的高速铁路线架设光伏系统,年发电量超过7×10⁴GWh,接近三峡大坝的年发电量,能有效缓解铁路电网压力;时速350 km/h的列车全速运行时,其上方4.5 m处的光伏组件表面压强分布正/负极值为140 Pa/-225 Pa,风速极值为3.5 m/s,满足光伏组件最大风载荷极限值要求,高速铁路光伏系统节能减排效益显著,并具有投资的经济可行性。     

Autonomous BDFIG-wind generator with torque and pitch control for maximum efficiency in a water pumping system

This paper presents and analyzes the operation strategy for an autonomous wind energy conversion system oriented to water pumping. It consists of a wind turbine with a Brushless Doubly-Fed Induction Generator (BDFIG), electrically coupled with a squirrel cage induction machine moving a centrifugal type water pump. Because of no brushes and slip rings, the BDFIG is suitable for autonomous systems, which often work in hard conditions. Additionally, the power flow on the BDFIG principal stator could be driven from a fractional power converter connected on the auxiliary stator winding. This Turbine-BDFIG and Motor-Pump configuration provides a high robustness and reliability, reducing the operational and maintenance costs. The operation strategy proposes, for wind speeds smaller than the rated, to maximize the volume of water pumped based on the optimization of the wind energy capture. To do that, a sliding mode control tracks the optimal turbine torque by means of a torque control. Meanwhile, for wind speeds greater than the rated, a pitch control keeps the water pump within the safe operation area by adjusting the speed and power of the turbine in their rated values. To assess and corroborate the proposed strategy, simulations with different wind profiles are made.     

Power curve tracking in the presence of a tip speed constraint

This paper considers the problem of power regulation for a variable speed wind turbine in the presence of a blade tip speed constraint, for example to limit noise emissions. The main contribution of the paper is the formulation of a policy for the regulation of the machine in the transition region between the classical regions II and III that accommodates the tip speed constraint, and the derivation of associated wind schedules for the rotor speed, blade pitch and aerodynamic torque. To exemplify the possible use of such wind schedules in the design of control laws, model-based controllers are formulated in this paper that are capable of performing power curve tracking throughout all wind speeds, in contrast with commonly adopted approaches that use switching controllers to cover the various operating regimes of the machine. The proposed regulation policies and control laws are demonstrated in a high fidelity simulation environment for a representative 3 MW machine.     

Exploitation of moderate wind resources by autonomous wind electric pumping systems

A laboratory test rig has been developed, in order to analyse the mutual interaction of the different components of a low power WEPS, in the presence of arbitrarily chosen wind intensity. The performances with moderate wind speed of a system composed by a horizontal axis, fixed-pitch wind turbine, a synchronous generator and a centrifugal electric pump have been investigated, both at the start and under steady-state conditions. A control strategy of the alternator field voltage, which facilitates the starting of the pump in the presence of modest wind intensity and maximises average water discharge under any wind condition, has been defined, implemented on an electronic board and tested.     

基于运行曲线的机械式风力提水机组匹配性设计方法研究

为改善风力提水机组设计中的部件匹配性问题,提高提水机组运行效率,提出一种机泵分离式风力提水机组匹配性设计方法。通过各部件运行曲线之间的工作点追踪与交叉确定风轮、空气压缩机以及隔膜泵之间相匹配的最佳设计点。并依照该方法设计试验样机,通过对样机的监测,各个运行参数之间的相关性与理论一致,样机运行稳定。该匹配性设计方法可普遍适用于机泵分离式风力提水机组,提高机组的寿命和运行效率。     

Wind energy from turbulence: Constant tip speed ratio operation

The ability of a wind machine, operating at constant tip speed ratio, to extract power from the turbulent eddy fluctuations in the wind is examined. A model is constructed relating the inertia of the machine to its ability to follow the fluctuations. The model includes a transfer function from which a cutoff frequency can be predicted. A field test on the University of Massachusetts experimental wind turbine yielded a cutoff frequency close to that of the model. The fraction of the additional energy available in the turbulent fluctuations to be extracted by the machine may be between 3% and 37% more than would be predicted from hourly average wind speeds. A responsive wind machine operating at constant tip speed ratio could extract approximately 70% of the additional energy. Further, machines that do not operate at constant tip speed ratio may produce less power in turbulent winds than would be predicted from an hourly average.     

Safety systems for the ESES 2002 wind pump

The ESES 2002 wind pump, a 4.6 m rotor diameter high-performance water pumping windmill, was tested at four different sites (Cairo, Giza, Wadi El Natroun and El-Tor city on the Red Sea coast) from September 1997 to July 1999. These machines utilize a 3:1 gearbox and a hydrodynamic sealing piston pump. These four ESES 2002 wind pumps were tested by pumping from a motionless water depth of 3 m up to an 84 m deep well. A variety of pump diameter sizes varying from 64 to 1400 mm were used. The water pumped was returned to the well after flowing through a settling storage tank having a capacity of 3 m³. The instrumentation provided a 16 channel data acquisition system to accurately measure the machine performance, including rotor rpm, number of stroke, starting wind speed, flow rate, tail furl angle and other variables. The results verify that the ESES 2002 wind pump is a robust machine as two machines have been running for 2 years continuously without requiring any replacement parts or major or minor maintenance.