水利水电工程专业英语 - 水电站与水轮机篇 - 图文

水利水电工程专业英语——水电站与水轮机篇 1. Energy and Power of Water Flow 1. 水流的能量和功率

As may be recalled from mechanics of fluids, the energy and power of a quantity of water in steady flow from A to B can be determined using Bernoulli’s theorem for specific energy. From the principle of conservation of energy it follows that the energy eA at A equals the energy eB at B plus the energy eAB released as the water flows from A to B. Assuming that the weight of the water is 1N, Bernoulli’s equation, which in effect expresses the law of conservation of energy, may then be written as

????+????+

????

2????????

2??

=

????+????????

+

2????????

2??

+?????? （1）

回顾流体力学，可以使用伯努利定理的比能来确定从A 到 B的一定量的稳定水流的能量和功率。根据能量守恒定律，A点的能量eA等于B点的能量eB加上水流从A到B的能量损失eAB。假设水体的质量是1N，那么实际上表述能量守恒的伯努利方程可以写作：

????+

????????

+

2????????

2??

=

????+????????

+

2????????

2??

+?????? （1）

Where ???? and ???? are respectively the elevations above a datum plane O-O of the centers of gravity of the stream cross sections at A and B(m), ????and ???? are respectively the pressures at the centers of gravity of the cross sections at A and B(Pa), ?? is the water density (kgm-3), ???? and ???? are respectively the average velocities of water at A and B(ms-1), g is the free fall accelerations (ms-2), and ???? and ???? are numerical coefficients accounting for a non-uniform velocity distribution over the cross sections (they are always larger than unity and generally range between 1.03 and 1.1).

其中????和????分别表示A和B处水流断面重心在基准面O-O以上的高程（m），????和 ????分别是A和B处水流断面重心的压力（Pa），??是水的密度（kgm-3），???? 和 ????分别是A和B处水的平均速度（ms-1），g是自由落体加速度，且????和????是考虑断面非均匀分布速度的数字系数（它们通常比单位的大，且通常范围为1.03-1.1）。

The first terms, z, on either side of Eq.(1), known as the elevation heads or potential heads, define the specific potential energy of water due to the elevation with respect to the selected datum. The second terms, ????, called the pressure heads, define the specific potential energy of water due to the respective pressure. The total specific potential energy may, therefore, be written as e=z+. It is the same for any point of a cross section, since an increase in z always

??????

??

produces a matching decrease in ????. Accordingly, the potential energy at a cross section may be evaluated in terms of the elevations of the points lying on the free surface of that cross section, assuming that ???? and e=h (where h is the elevation of the points on the free surface above the datum plane). Finally, the third terms, 2??, referred to as the velocity heads, define the specific 2????

??

??

kinetic energy of the quantity of water at the respective sections. Obviously, all the terms of Eq.(1) are measured in meters.

第一项Z在方程（1）两边都有，被称为位置水头或势头，确定了由于所选择的基准面得到高程的单位势能。第二项，被称为压力水头，确定了由于各自的压力产生的单位势能。

??????

因此，全部单位势能可以写作e=z+????。这对于一个断面任意点都是相同的，因为z的增加总是产生一个在相匹配的????的降低。相应地，某断面处势能可以以位于断面自由表面点的高程的形式提升，假设且e=h（其中h是基准面上方自由表面上点的高度）。最后，第三项，??指的????

2??

??

??2

??

??

是速度水头，确定了各断面处该质量水体的单位动能。很明显，方程（1）中所有的项都以米为单位。

Re-writing Eq.(1) for the free surface (with ????=0) yields

????+

2????????

2??

=????+

2????????

2??

+?????? （2）

Then, the lost head (or friction head) is given by

??????=?????????+

In reality, the difference

2????????

2????????

2??

?

2????????

2??

（3）

2??

?

2????????

2??

is negligibly small. So,

??????=?????????=HAB （4）

Here, HAB is the difference in elevation between the beginning and end of the portion AB (customarily referred to as the cross-head). If it is sea level (the elevation being Δ0) that is chosen as the datum plane, then hA=ΔA, hB=ΔB, and eAB=ΔA-ΔB=HAB.

对于自由表面（????=0）改写方程（1），得到

????+

那么，水头损失（或摩擦水头）即为

??????=?????????+

事实上，

2

????????

2????????

2????????

2??

=????+

2????????

2??

+?????? （2）

2??

?

2????????

2??

（3）

2??

?

2????????

2??

的差别可以忽略不计。所以，

??????=?????????=HAB （4）

此处，HAB是AB段开始和结束处的高程差（习惯上称之为水头差）。如果被选作参考平面的是海平面（高程为Δ0），那么hA=ΔA, hB=ΔB，且 eAB=ΔA-ΔB=HAB。

When the total energy of flow is desired, the respective terms in the above equations should be multiplied by the weight of the flowing fluid which depends on the discharge Q(m3s-1), meaning that over a time interval t the section A will let in, and the section B will let out, a quantity of water equal to Qt. Obviously, the weight of that volume of water is equal to Qt ??g, so the total energy (in joules) released as the water flows from A to B will be

EAB=HABQt ??g （5）

Power NAB, or the energy released per second, will be given by

NAB=

????????

HABQ ??g （6）

如果需要水流的全部能量，上述方程各项应该乘以取决于流量（m3s-1）的流体重量，意为在一个t的时间间隔内断面A处将流入、且断面B处将流出质量等于Qt的水量。很明显，该水体的重量等于Qt ??g，所以水流自A到B处释放的所有能量（单位为焦耳）将为

EAB=HABQt ??g （5）

功率NAB，或者每秒释放的能量，将表示为

NAB=

????????

HABQ ??g （6）

Since the total energy is in joules, the dimension of power is the watt (W). However, the watt is too small a unit. So, in power engineering, use is most commonly made of its multiples, such as the kilowatt(1kW=1000W) and the megawatt (1MW=1000kW=106W).

由于总量能的单位是焦耳，所以功率的单位就是瓦特（W）。然而，瓦特这个单位太小了。所以，在电力工程中，通常用它的倍数，比如千瓦（1千瓦=1000瓦）和兆瓦（1兆瓦=1000千瓦=106瓦）。

Considering that g=9.81m2s-1 and ??=1000kgm-3 (for pure fresh water), the power in kilowatts may be written as

NAB=9.81QHAB （7）

In power engineering, the common unit of measure for energy is the kilowatt-hour (1kWh=3600J). If the time interval T in question is expressed in hours, then the energy ?????? in kilowatt-hours will be given by

EAB=9.81QHABT （8）

Giving per year (T=8760h)

????????

??????=85936QHAB （9）

考虑g=9.81m2s-1 且??=1000kgm-3（对于纯鲜水），单位为千瓦的功率可以写作

NAB=9.81QHAB （7）

在电力工程中，度量能量的通常单位是千瓦·时。如果上述的时间间隔T是以小时表述的，那么以千瓦时为单位的能量??????就可以写作

EAB=9.81QHABT （8）

给定每年（T=8760小时）

????????

??????=85936QHAB （9）

Eqs. (7) and (9) are used to determine the potential of a watercourse in terms of its power or annual energy found on the basis of the average discharge through several years of record. The theoretical hydroelectric potential of a watershed, a region, or a country is evaluated by dividing the area in question into suitable sections and adding together the power and annual energy found for each section. Naturally, it seldom happens that all of the water bodies in a region can be used for power generation. The common practice is to locate the water courses (or their portions) that can be used by the industry and to determine what may be called their technical hydroelectric potential. Part of the technical potential whose development is economically advisable at a given time is termed the economic hydro potential. Of course, the last-mentioned quantity depends on the demand and overall economic situation and is, therefore, subject to certain variations.

基于若干年平均流量记录，方程（7）和（9）用于确定水系的功率或年发电量的潜力。一个流域、区域或国家的理论水电潜力是通过将上述区域分成合适的部分并将每个部分得出的功率和年发电量相加而评估的。通常来讲，很少存在某区域内的所有水体都可以用作发电的情况。通常做法是定位能够用作工业用途的水系，并确定其所谓的水电技术可开发潜力。

在给定时间经济可行的开发的技术潜力部分被称为经济水电潜力。当然，最后提到的数量决定于需求和整体经济情况，因此受到某些变量的影响。

2. Intake Structures 2. 取水建筑物

An intake structure is an arrangement by which water is satisfactorily diverted for the required use. Thus as shown is Figure 1, the intake is an arrangement which allows for water to be taken from its source and then discharged into the conveyance system from which it is led to the desired use. The desired use of water may be for domestic water supply, flood or irrigation discharge out of a dam through outlet outsluices, or for the purposes of generating electricity. 取水建筑物是通过其就可以将需要使用的水满足要求地调动的建筑物。正如图1中所示，进口就是允许从水源取水的建筑物，且随后排放到引向期望用途的输水系统内。水的期望用途可能是用作生活供水、大坝通过出水口的洪水或灌溉放水，或者是用于发电的目的。

Figure 1 Diagrammatic sketch of function of intake

图1 取水建筑物功能示意图

Irrespective of the desired use an intake structure should fulfill the following requirements: (1) assured water supply; (2) suitable quality of water; (3) control over supply of water.

The requirements of assured water supply would fix the location of the intake in (1) plan so that water is always available; (2) elevation so that the invert level of the intake is at such a location that the minimum water level is always above this invert level.

不管期望用途如何，一个取水建筑物都应该满足一下要求： （1）确保供水； （2）合适的水质； （3）控制供水。

确保供水的需求将会将取水定位于（1）总能够获得水的平面；（2）确保最低水位总是高出引水高程的高度。

The quality of water required would depend upon the use which the water is desired to be put to. In hydroelectric development general requirement for the quality of water will be that it should be free from debris, trash, ice and silt. In case of an irrigation scheme it may be desirable that the water is free from undesirable salts and other industrial effluents which harm the crop.

所要求的水质将取决于其期望的用途。在水力发电工程中通常对水质的要求时它应该

不含漂浮物、污物、冰和泥沙。对于灌溉计划，水应该不含不期望的盐分以及其它伤害作物的工业排放物。

An intake structure should always have an arrangement by which it may be possible to control the flow of water. This arrangement is generally provided for by introducing hydraulic gates and sometimes valves in the intake structure.

取水建筑物应该总设置一个可以控制水流的建筑物。这个建筑物通常在取水建筑物中以引进液压式闸门和阀门的形式存在。

Thus, according to the operating head the intake may be classified into: (1) low head intake, (2) medium head intake, and (3) high head intake.

因此，根据工作水头进水口可以被分成（1）低水头取水口，（2）中水头取水口，和（3）高水头取水口。

Taking into account the conveyance system they may be grouped under: (1) canal intake, (2) dam intake, and (3) tunnel intake.

考虑输水系统它们可能被分为以下组：（1）渠道式取水，（2）坝式取水，和（3）管道式取水。

3. Penstocks 3. 压力管道

A penstock is defined as a pressure pipe whose function is to supply water directly to hydraulic turbine.

压力管道被定义为具有直接向水轮机供水功能的压管。

Penstocks are intended to handle high stream velocities (up to 12 ms-1) and to resist dynamic loads imposed by water hammer. Therefore, they are commonly made of steel pipe. Other constructions, such as steel/reinforced-concrete penstocks, reinforced-concrete penstocks, reinforced-concrete penstocks or wood penstocks, are used far less frequently.

压力管道要承受高速水流（高达12m/s）并抵抗由水击强加的动荷载。因此，它们通常用钢管制成。其它建筑物，如钢/钢筋混凝土压力管道、钢筋混凝土压力管道或木质压力管道则采用的少得多。

We have already mentioned that penstocks may be of the embedded, buried, and open (exposed) types. Let us now discuss each type in detail.

我们已经提到压力管道可能是埋管、回填管和明管型式。现在让我们详细地讨论每种类型。

Embedded penstocks are made of steel pipe 7 to 10m in diameter, built in a concrete dam or directly in rock. When embedded in concrete, the pipes are reinforced with strong steel hoops. The gap between the penstock and the rock is packed with cement grout or filled with plain concrete or reinforced concrete.

埋管用直径为7-10米的钢管制成，修建在一个混凝土大坝或直接在岩石中。当埋在混凝土中时，钢管用强钢箍加固。压力钢管和岩石之间的缝隙用水泥浆填充或用混凝土或钢筋混凝土填满。

Buried penstocks are made of steel or reinforced concrete pipe laid on a gravel or a concrete cushion in backfilled trenches. Reinforced concrete penstocks which are used most commonly may be up to 6 m in diameter (sometimes, even larger). Steel penstocks whose

diameter never exceeds 3 m are employed very seldom, because they are rather inconvenient for inspection and maintenance.

回填式压力钢管用钢管或钢筋混凝土管制成，放置在卵石或一个回填沟的混凝土垫层上。最常用的钢筋混凝土压力管道直径最大可达6米（有时可更大）。直径不超过3米的钢压力管道应用的非常少，因为它们在检修和维护方面相当不方便。

Open (exposed) penstocks are, in effect, welded steel pipelines up to 9 m in diameter, installed on concrete supports placed directly along the slope. There also exist reinforced concrete and wood constructions, but these are used less frequently. Open penstocks may be either of the continuous (rigid) type or of the split multispan type. Continuous penstocks are rigidly fixed at the two ends by anchorage supports and, therefore, suffer considerable stresses as they expand or contract under temperature variations. This can readily be avoided by splitting the penstock into several spans each of which is fixed by anchorage supports of its own. An expansion joint is installed in each span to allow the penstock to expand or contract under temperature variations without giving rise to any additional stresses. Between the anchorages, the pipes rest on a number of intermediate supports designed to carry the weight of the filled penstock only and to provide for the free movement of the pipe caused by thermal expansion or contraction.

事实上，明管（暴露）压力管道是直径达到9米的焊接钢管道，直接沿着坡安装在混凝土支撑物上。同事存在钢筋混凝土和木质建筑物，但是这些用的很少。明管压力钢管可能是连续（刚性）式或分段式。连续式压力管道被通过镇墩刚性地固定在两端，然后在其受到温度变化导致的扩大或收缩时受到相当大的压力。这可以通过将压力管道分成几段时就可避免，每段由本身的镇墩固定。每段中都安装了伸缩机以允许压力光管在温度变化是扩大或收缩而不增加任何附加应力。在镇墩之间，管道也放置在很多的支墩上，它们被设计于仅承受充满压力钢管的重量，且提供由热膨胀或收缩引起的管道的自由运动。

4. Water Hammer in Penstocks 4. 压力管道中的水击

When the flow of water through, say, a penstock is stopped too rapidly, the water pressure suddenly rises above the normal level and might cause the penstock to burst. Quite appropriately, this phenomenon has come to be known as the water hammer.

当水流通过时，例如，一个压力管道非常迅速地关闭了，水压迅速上升至正常水平以上且可能导致压力管道爆裂。这个现象被很恰当地称作“水击”。

Picture to yourself a conduit of length L and cross-sectional area F through which water uniformly flows at a velocity v(Figure 1). Assume also that a gate installed at the end of the conduit (or wicket gates in the case of a penstock) has closed instantly and brought the water to a sudden stop. Following the stop, the kinetic energy of the water vanishes, resulting in an equivalent increase in its potential energy, which manifests itself in a pressure rise Δph.

设想水流以v的速度均匀通过一条长为L且断面面积为F的输水管（图1）。再假设安装在输水管尾端的闸门（或者在压力管道情况下的导叶闸门）瞬时关闭并导致水流突然停止。随着该停止，水流的动能小时，引起了在其势能上的相等的增加，这在其展现为Δph的压力上升。

Since the conduit walls possess certain elastic properties, the pressure rise cannot propagate instantaneously throughout the conduit. Over a time interval dt, the pressure riseΔph will travel a distance dl. Within dl, the walls will expand and the conduit will “swell” as shown schematically in Figure 1(a). As this process goes on, the pressure wave travels up the conduit to the forebay at a velocity a. The velocity of the pressure wave depends on the elastic characteristics of the conduit and water and would be equal to the velocity of sound in water (1425ms-1) if the conduit walls were absolutely rigid. Under real conditions, however, it is determined as

??=

1425 1+??0

??????

（1）

where ??0 is the modulus of elasticity of water (2×103MPa)，E is the modulus of elasticity of the wall material (2×105MPa for steel), ?? is the wall thickness, and D is the conduit diameter. For steel conduits, a is approximately adopted as 1000 ms-1.

由于输水管壁具有一定的弹性性能，该压力上升不能立刻通过输水管传播。在dt的时间间隔内，压力上升Δph会传播一个dl的距离。如图1所示，在dl内输水管壁将会扩大且输水管将“膨胀”。随着这个过程的推进，该压力波以速度a沿着输水管传播至前池。压力波的速度取决于输水管的弹性特性和水，并且如果输水管壁为绝对刚性，那么它的速度将等于声音在水中的传播速度（1425ms-1）。然而在实际情况中，它被确定为

??=

1425?? 1+??0

????

（1）

其中??0是水的弹性模量（2×103MPa），E是壁材料的弹性模量（钢材2×105MPa），??是壁厚，且D是输水管直径。对于钢输水管，a近似采用1000 ms-1。

Figure 1 Water hammer in a penstock

(a) forward pressure wave; (b) backward pressure wave.

图1 压力管道中的水击

（a）向前压力波；（b）向后压力波。

Following the sudden closure of the gate, Δph reaches its ultimate value Δpul which can be found by equating the change in water momentum over a time dt to the impulse of the associated force

????

Whence

??(d??)??=Δpul

????d????

=ΔpulFdt

Considering that dl/dt=a, we may write for the ultimate pressure rise and the ultimate water-hammer head

????????=(g)??g （2） ??H????=

???? g????

The second line in Eq.（2） is called the Zhukovsky formula.

随着闸门的突然闭合，Δph达到了它的最终值Δpul，这可以通过将水动量在dt时间内的变化与相应力的冲量作等式而获得

????

由此得到

??(d??)??=Δpul

考虑dl/dt=a，我们可以写出最终压力上升和最终水击水头为

????????=()??g （2）

g????

????d????

=ΔpulFdt

??H????=

???? g方程（2）中的第二行被称作茹科夫斯基公式。

Let us now consider what happens as the positive pressure wave resulting from the water hammer travels up the penstock to the forebay. Upon reaching the forebay, it is reflected back from the open end of the penstock as a negative pressure wave which has the same magnitude and travels back at the same velocity a as the positive wave (Figure 1b). As soon as the backward negative wave reaches the closed gate, it is again reflected back to the open end as a positive wave. This process goes on until the waves gradually die out because of the inevitable losses of energy taking place under real conditions. The time of one round trip of the wave is called the time of one interval or the critical time of the pipe. It is expressed in seconds as

tcr=a （3）

现在我们考虑由水击沿着压力管道传播到前池而产生的是正水击波。一旦到达了前池，它就会以负水击波的形式从压力钢管的开放尾端反射回去，它大小相同且以与正波相同的速度回传（图1b）。一旦向后的负波达到关闭的闸门，它又作为正波被反射至开口尾端。这个过程一直持续，直到由于实际情况中发生的不可避免的能量损失使得水波逐渐消失。水波往返一次的时间被称作1间隔的时间或管道的临界时间。它以秒为单位表示为

tcr=a （3）

Under real conditions, the gate is never closed instantly, so the negative pressure wave finds itself superimposed on the positive wave, which to a certain extent relieves the pipe of the water hammer. As a result, Δph is always smaller thanΔpul.

在实际情况中闸门并从不是瞬时关闭，所以负波与正波相叠加，这在某种程度上缓解了管道的水击。作为结果，Δph总是比Δpul小。

2??2??

5. Surge Tanks 5. 调压井

The simplest means of eliminating positive (or negative) water-hammer pressure and improving speed-regulation conditions is to provide a bypass to take the rejected flow. This may be accomplished by what are known as surge tanks. Surge tanks are generally installed either at the lower end of a pressure diversion conduit to link the diversion conduit to the penstocks or at the lower end of long penstocks leading from a dam to an isolated power house. Surge tanks may also be provided at the upper end of a long tailrace diversion system. Whether or not a conduit requires a surge tank depends on its Tw. As a rule, the need for a surge tank arises when

Tw＞3 to 6 （1）

消除正（或负）水击压力和改善转速调节条件的最简单的方式是提供一个旁通道以接纳反射水流。这可以通过所谓的调压井完成。调压井通常安装在压力导流输水管的低端以连接导流管和压力管道，或者在自大坝到一个独立发电厂房的长压力管道的低端。调压井也可放置在一个长的尾水系统的上端。输水管是否需要一个调压井取决于其Tw。一般来说，当下述情况发生时，就需要调压井

Tw＞3 to 6 （1）

Figure 1 principle of operation of surge tank

1—pressure gradient when surge-tank level is a maximum; 2—pressure gradient when surge-tank level is a minimum. 图1 调压井的运行规则

1—当调压井级别最高时的压力梯度； 2—当调压井级别最低时的压力梯度。

图1 调压井运行原则

1-当调压井水位最高时的压力梯度； 2-当调压井水位最低时的压力梯度。

Let us discuss the principle of operation of a surge tank (Figure1). When the turbines

operate at a constant velocity and a uniform discharge, the free-surface level of the tank is by ????????=+

????22??

lower than the static headwater level, where ???????? is the head lost in the diversion

system. When the wicket gates are closed and the turbine is unloaded, the flow through the penstocks comes to a standstill, and the water arriving with the initial velocity is rejected into the surge tank, thereby raising its level. As this takes place, the kinetic energy of the flowing water is converted into the potential energy of the water stored above the normal surge-tank level.

我们来讨论调压井的运行规则（图1）。当水轮机以一个恒定速度和均匀流量时运行，井的自由表面水位比（水库）静止上游水位低????????=+

????22??

，其中????????是输水系统的水头损

失。当水轮机甩负荷导叶关闭时，压力管道中的水流突然停止，而引水道中仍以初始流速流来的水体被迫流入调压井，从而使调压井中的水位升高。当这种情况发生时，水流的动能转换为势能储存在调压井正常水位之上的水体中。

The pressure wave which is reflected from the free surface cannot propagate into the conduit and is eventually suppressed, resulting in an appreciable decrease inζ. When all of the kinetic energy of the rejected water is converted into potential energy, the tank level becomes by Zm higher than the head water level. At this instant, the velocity of stream flow through the diversion conduit equals zero. However, this state is by no means stable, and the water soon begins to flow out of the tank into the conduit.

从自由表面反射的压力波不能传递至输水管并最终被抑制，导致了ζ中明显的减少。当反射水流的所有动能都转换成势能时，调压井水位比上游水位高出Zm。此时，流过输水系统的水流速度等于零。然而，这个状态并不是稳定的，水流很快就开始回流入输水管。

The accompanying pressure fluctuations are eventually damped by the friction between the water and the walls of the conduit and the surge tank. After the fluctuations have been suppressed completely, the water in the tank attains a new level corresponding to the new load on the turbine or equal to the static headwater level if the gates have been closed to zero. Assuming the cross-sectional area of the tank as ????, the cross-sectional area of the diversion conduit as ????????, and the length of the conduit as L, the period of pressure fluctuations may be developed as

??=2?? ?????? （2）

??????

????

伴随的压力波动最终通过水和输水管壁及调压井之间的摩擦而减弱。在波动被完全抑制后，井中的水达到了与水轮机上新负荷相对应的水位，或者如果闸门完全关闭时与静止上游水位相同。假设井的断面面积是????，输水管的断面面积是????????，且输水管的长度是L，那么压力波动的时间就可以表示为

??=2??

????????????????

（2）

When the load on the turbines is suddenly increased, the tank level falls by, and similar pressure fluctuations take place. The analysis of this situation should be based on the lowest headwater level. The thing is that the pressure gradient following the drop in tank level will give the elevation above which the diversion conduit ought not to be laid if it is to be protected against vacuum.

当水轮机的荷载突然增加时，井中水位随之下降，且发生相似的压力波动。对这种情况的分析应该基于最低的上游水位。问题是，如果要防止出现真空，就要保证随着井水位下

energy. The second type is a reaction turbine, which develops power from the combined action of pressure energy and kinetic energy of the water. Reaction turbines can be further divided into several types, of which the principal two are the Francis and the propeller.

水轮机是通过水流动力和压力作用而产生扭矩的机械。它们可以分为两类。一种是冲击式水轮机，它利用高速射流的动能将水能转为机械能。第二种类型是反击式水轮机，它通过水流的压力和动力的综合作用产生动力。反击式水轮机可以进一步被分为几种类型，其中两种基本形式是法兰西斯式水轮机和螺旋桨式水轮机。

9.1 Impulse Turbines 9.1 冲击式水轮机

The impulse turbine is frequently called a Pelton wheel after one of its early developers, Lester Pelton. The potential energy of water flowing from a fore bay through a penstock is transformed into kinetic energy in a jet or jets of water striking the single or double bowl-shaped buckets of the impulse runner. The jet of water strikes the runner tangentially to a circular line of the pitch diameter of the buckets and acts at atmospheric pressure.

冲击式水轮机通常被叫做佩尔顿式水轮机，以其早期开发者之一的Lester Pelton的名字命名。流过压力管道的前池水流的势能被转换为射流的动能，作用在冲击转轮的单个或两个碗状的斗叶上。射流沿着斗叶的节圆直径的圆圈切线防线并以大气压力作用在转轮上。

The water striking the buckets of the runner is regulated through the use of a bulb-shaped needle in a nozzle. The position of the needle determines the quantity of water striking the runner. A deflector arrangement in more sophisticated designs is used to direct the water away from the turbine buckets when there is a load rejection to reduce hydraulic torque on the generator.

作用在转轮斗叶上的水流通过在喷嘴中的灯泡形状的针杆来调控。针杆的位置确定了作用在转轮上的水量。当要发生减少发电机液压扭矩的甩负荷时，要用一个设计更加复杂的偏流器装置将水流从水轮机斗叶处引离。

Impulse turbines are usually high head units and used at locations where heads 1000ft or more. They are also used at lower heads for small-capacity units. The ratio of the wheel diameter to the spouting velocity of the water determines the applicability of an impulse turbine.

反击式水轮机通常是高水头机组，并应用在水头在1000英尺或更高的位置。它们也应用在小容量机组的低水头情况。水轮机直径与射流速度的比值决定了反击式水轮机的适用性。

The impulse or Pelton turbines have advantages for high-head installations, for installations with abrasive matter in the water, and for long-penstock installations where water hammer is critical. Some impulse runners are made with individually bolted buckets and others are solid cast. Double-overhung installations are made with a generator in the center and the runners positioned in the two overhanging ends of a single shaft.

反击式或佩尔顿式水轮机在高水头安装、存在水中磨损问题的安装和在水击很重要的长压力管道安装的情况中有优势。一些反击式水轮机被制作成单独带有螺栓连接的斗叶形式，另外一些则为整体铸造。双悬臂式安装中发电机在中心且转轮定位在单轴两个的突出端。

Another design of an impulse turbine is the Turgo Impulse turbine invented by Eric Crewdson of Gilkes and Co. Ltd. Of England in 1920. The turbine is designed so that the jet of water strikes the buckets at an angle to the face of the runner and the water passes over the buckets in an axial direction before being discharged at the opposite side. The buckets are constrained by a rim on the discharge side of the runner. The advantage claimed for the type of

unit is that a larger jet can be applied, resulting in a higher speed with a comparatively smaller machine.

冲击式水轮机的另外一种设计是由Gilkes的Eric Crewdson和英格兰公司在1920年发明的Turgo冲击式水轮机。水轮机的设计为射流以与转轮面成某一角度作用在斗叶上，且水流在在对面排出前以轴向通过斗叶。斗叶受到转轮出水侧的边缘的限制。这种形式机组的优点是可以应用一个更大的喷口，从而得到一个更高的速度和一个相对较小的机械。

9.2 Mixed-Flow Reaction Turbines 9.2 混流式反击水轮机

In the operation of reaction turbines, the runner chamber is completely filled with water and a draft tube is used to recover as much of the hydraulic head as possible. Three conditions of flow determine the designs of reaction wheels. If the flow is perpendicular to the axis of rotation, the runner is called a radial-flow turbine. An early type of radial-flow machine was the Fourneyron turbine, in which water flow was radially outward. Many early reaction wheels were radially inward-flow runners. If the water flow is partially radial and partially axial, it is called a mixed-flow turbine. The most common mixed-flow turbine was developed by James B. France and bears his name. Francis turbines have a crown and band enclosing the upper and lower portions of the buckets, while a propeller-type runner has blades projecting from the hub.

在反击式水轮机的运行中，水流完全充满转轮室，且尾水管被用来回收尽可能多的水头。三种水流条件确定了反击式水轮机的设计。如果水流与转动轴向相垂直，那么该转轮被称为径向流动水轮机。径向流动机械的早期类型是Fourneyron水轮机，其中水流径向流出。很多早期的反击式水轮机都是径向入流式水轮机。更常用的混流式水轮机是James B. France开发的并以他的名字命名。弗兰西斯水轮机有一个上冠和下环封装着斗叶的上部和下部部分，而一个螺旋桨式转轮有从轮毂伸出的叶片。

Another type of mixed-flow reaction turbine is the diagonal turbine or Deriaz turbine. The runner blades are set at an angle around the rim of a conical hub. There is no band around the blades. The blades are adjustable and can be feathered about an axis inclined at 45°to the axis of the shaft. The units have been developed for use as reversible pump turbines. They have the advantage of maintaining good efficiency over a wide range of flow, higher-strength attachment of the runner blades to the turbine hub, and the arrangement allows higher permissible operating heads than an axial-flow Kaplan or adjustable blade unit.

另外一种混流式水轮机是斜流式水轮机或Deriaz水轮机。转轮叶片被以一定的角度环绕着锥形轮毂而设置。叶片周围没有带子。叶片可以调整并以与转轴轴线45度的倾角顺桨。该机组已经被开发为可逆式水泵水轮机。它们的优势是在较宽水流范围内保持良好的效率，转轮叶片与水轮机轮毂之间更高强度的连接，并且该设备可以在比轴流Kaplan或可调整叶片机组的更高的水头下运行。

9.3 Axial-Flow Reaction Turbines 9.3 轴流式反击水轮机

The direction of flow for most propeller turbines is axial, parallel to the axis of rotation; thus they are classified as axial-flow turbines. Early developments utilized propeller unit vertical shafts. More recent developments utilize a horizontal shaft. Propeller turbines can have the blades of the runner rigidly attached to the hub; these are called fixed-blade runners. The blades of the runners can also be made adjustable so that the turbine can operate over a wide range of flow

conditions at better efficiencies. A propeller turbine with coordinated adjustable blades and gates is called a Kaplan turbine after its inventor, Viktor Kaplan. A propeller turbine with adjustable blades and fixed gates is sometimes referred to as semi-Kaplan. The automatic coordination of the movement of runner blade and adjustment of the gate positions provides optimum hydraulic performance and has made such units more efficient for variable flow and low-head applications. 大多数螺旋桨式水轮机的水流方向是轴向，与转动轴向方向相平行；因此它们被分类为轴流式水轮机。早期开发利用螺旋桨机组垂直轴。较近的开发使用水平轴。螺旋桨式水轮机可能有刚性地连接到轮毂的转轮叶片；这些被称为固定叶片式转轮。转轮叶片也可以被制成可调式，这样水轮机就可以以更好的小路在一个更宽的水流条件下运行。配有协调可调式叶片和导水叶的螺旋桨式水轮机被以其发明者Viktor Kaplan的名字命名为卡普兰水轮机。配有可调整叶片和固定导水叶的螺旋桨式水轮机被称为半卡普兰式。转轮叶片运动的自动协调和导水叶位置调整提供了最佳水力性能，且对于可变化水流和低水头应用情况使得这样的机组效率更高。

Recent developments utilizing axial-flow runner have included arranging the runners in specialized configurations sometimes referred to as tubular-type turbines. Basically, the units are arranged to minimize the change in direction of flow, to simplify the mounting of the generator, and to provide the best hydraulic characteristics for the water moving through the hydropower plant. TUBE turbine is a registered trademark of the Allis-Chalmers Corporation for a type of unit in which the generator is mounted outside the water passage with direct or gear drive connection to the generator. These units are now being produced in standardized sizes.

使用轴流式转轮的近期开发已经包括了在专门构型中的转轮，有时被称为贯流式水轮机。基本上，这样的机组布置尽量减少水流方向的变化，简化发电机的安装，使水流流过电厂时具有最好的水力特性。贯流式水轮机是Allis-Chalmers有限公司的机组类型的注册商标，其中发电机被安装在流道外，流道与发电机直接或通过齿轮传动相连。这些机组现在正以标准化型号生产。

Bulb hydropower units include propeller turbines that drive a generator encapsulated and sealed to operate within the water passage. The generator design is such that all mechanisms are compressed into a diameter that is approximately equal to the propeller diameter. The very compact nature tends to provide some advantages in powerhouse design and in pattern of water flow. It does require special cooling and air circulation within the generator bulb. This type of unit is being manufactured by several companies.

灯泡水电机组包括封装并在流道内运行的驱动发电机的螺旋桨水轮机。发电机被设计成所有的机械的直径都被压缩成与螺旋桨直径大致相等。这样非常紧凑的特性在厂房设计和水流形式中较有优势。它确实需要在发电机灯泡室内特殊的冷却和空气循环。有几家公司可以制造这种机组。

10. Turbine Cases 10. 水轮机蜗壳

A turbine case may be defined as a water passage surrounding a turbine. Its primary function is to distribute uniformly the water around the stay ring, the wicket gates, and the runner. To vertical-shaft turbines the water is conveyed from one side, so their cases are made

spiral in shape with the outer wall completely or partially embracing the staying ring. Quite appropriately, turbine cases of this configuration have come to be known as spiral cases. The basic parameter of a spiral case is the volute angle Фvol made by the planes passed through the throat and the small end.

水轮机蜗壳可以被定义为环绕水轮机的流道。其首要功能是均匀地分配环绕座环、导水叶和转轮的水流。对于垂直轴水轮机，水流从一侧传输，因此其蜗壳被制成螺旋状且其外墙完全或部分地环抱着座环。这样配置的蜗壳很合适地被称作螺旋型蜗壳。螺旋型蜗壳的基本参数是蜗壳的包角Фvol，即从蜗壳进口到蜗壳末端的平面角度。

There exist two basic types of spiral cases, namely concrete cases with a volute angle of 180°to 270° and metal cases with a volute angle of 345° to 360°. Concrete spiral cases are used under heads up to 80m. They may be symmetrical in radial cross section or have an extended lower or upper portion. When the head on the turbine exceeds 50m, concrete cases are lined with metal. As a rule, concrete cases are used for adjustable-blade propeller (Kaplan) turbines, although, on some rare occasions, they are employed for low-head Francis turbines.

螺旋型蜗壳有两种基本类型，即角度为180°到 270°的混凝土蜗壳，以及角度为345°到 360°的金属蜗壳。混凝土螺旋型蜗壳应用于水头低于80米的情况。它们可以是径向横截面对称的或有一个延长下部或上部结构。当水轮机水头超过50米时，混凝土蜗壳就用钢板做内衬。按规定，混凝土蜗壳被用于可调整叶片式螺旋桨（卡普兰）水轮机，尽管在很少的情况下，它们也用于低水头的弗兰西斯水轮机。

For large vertical-axis turbines, semi-spiral or reinforced concrete spiral cases are used. The advantage of the semi-spiral case is lower head loss. The head loss is also lower for an open-flume arrangement than for more sophisticated spiral casings. For large-, medium-, and high-head turbines the spiral case is usually fabricated from steel plate. Older installations sometimes had cast steel or cast iron spiral cases. The water passageways are different for various types of turbines.

对于大型垂直轴水轮机，要使用半螺旋或钢筋混凝土螺旋型蜗壳。半螺旋型蜗壳的优点是低水头损失。开放式水槽装置比更加复杂的螺旋型蜗壳的水头损失也更低。对于大型、中型和高水头的水轮机，螺旋型蜗壳通常用钢板制就。早期的安装有时用铸钢或铸铁螺旋型蜗壳。该流道不同于很多型式的水轮机。

Metal spiral cases are an excellent choice for Francis and high-head Kaplan turbines operating under heads ranging from 40 to 500 m. They are traditionally circular in cross section throughout, and are made of welded plate steel, or under higher heads, of cast iron or cast steel. 对于在在40到500米之间水头下运行的弗兰西斯和高水头卡普兰水轮机来说，金属螺旋型蜗壳是一个非常好的选择。它们通常在全断面上都是圆形，并用焊接钢板制就，或者在更高的水头下用铸铁或铸钢制就。

Water velocities and uniformity of flow are primary engineering concerns. Water velocities in the spiral casing as a rule of thumb, according to Brown (1970), should, for low-specific-speed turbines, be approximately

??=0.14 2???? （1）

and for high-specific-speed turbines,

??=0.20 2???? （2）

where v= water velocity at cross sections normal to the radius and at entrance to spiral case, ft/sec; h=design net head, ft.

水流速度和均匀度是设计的首要考量。根据Brown (1970)的经验，对于低比转速的水轮

机，在螺旋型蜗壳内的水流速度应大致为：

??=0.14 2???? （1）

且对高比转速水轮机：

??=0.20 2???? （2）

其中v=垂直径向断面及螺旋型蜗壳进口处的水流速度，英尺/秒；h=净设计水头，英尺。

Generally, there should be no deceleration of water as it flows from the penstock to and through the spiral case. Special requirements as to shape, dimensioning, and velocity are needed for different kinds of turbines.

通常来说，当水流从压力管道流向并通过螺旋型蜗壳时，水流速度不应该减小。对于不同类型的水轮机来说，其所需的形状、尺寸和速度都有特殊需求。

11. Draft Tubes 11. 尾水管

Draft tubes are the final components of the water passages of hydropower plants. A draft tube may serve the double purpose of (1) allowing the turbine to be set above tailwater level, without loss of head, to facilitate inspection and maintenance, and (2) regaining, by diffuser action, the major portion of the kinetic energy delivered to it from the reaction-turbine runner.

尾水管是水电站水流通道的最后部分。尾水管可以起到双重目的（1）允许将水轮机设置在尾水位之上，不产生水头损失，以便于检修和维护，以及（2）通过扩散作用重新获得从反击式水轮机转轮传到其中的大部分动能。

Draft tubes usually consists of steel sections which change shape from circular to rectangular in cross section. The sections expand in cross-sectional area to decrease the water velocity with a minimum occurrence of vortexes and maintain a nearly uniform velocity at any section. The draft tube is usually formed in reinforced concrete. The principal engineering problems are determining the water velocity at the exit to the draft tube and determining the controlling dimensions of the draft tube.

尾水管通常包括钢结构，其横截面形状从圆形变为矩形。该面积在横截面扩大，以减小水流速度并将涡流发生降至最低，并在任意断面维持一个接近均匀的速度。尾水管通常用钢筋混凝土制成。主要的设计问题是确定出口进入尾水管处的水流速度，以及确认尾水管的控制尺寸。

As regards the shape of a draft tube, the best performance could be obtained with the conical tube. Unfortunately, its length would be great in terms of throat diameter, and therefore, for large machines it would require a considerable amount of excavation. For this reason, it is used only relatively small machines, the draft tube for large vertical-shaft turbines being mostly of the elbow construction. In fact, the elbow type of tube is now used with most turbine installations. With this type, the vertical portion begin with a conical section which gradually flattens in the elbow section of elaborate shape and then discharges horizontally through substantially rectangular diffuser section to the tailrace. One or two vertical piers are placed in the horizontal portion of the tube for structural reasons. The basic dimension of any draft tube is the height h. Obviously, the greater the height of the draft tube, the better the turbine

performance. On the other hand, higher draft tube call for more concrete, thereby building up the cost of the power house. For this reason, an optimum must be found that would be economical of materials and still ensure an acceptable performance, as too low draft tubes have proved to be very little help.

至于尾水管的形状，直锥形尾水管可能获得最佳性能。不幸的是，由于其喉部直径，它的长度将较大，而且因此，对于大型机械，它可能会需要非常可观的开挖量。因此，它仅用相对较小的机械，对于大型垂直轴水轮机的尾水管，通常是弯肘建筑物。事实上，弯肘型尾水管目前最普遍地应用于水轮机安装中。对于这种类型，垂直段通常开始于直锥段，它在肘管段逐渐趋于复杂形状，随后水流通过大致呈矩形的扩散段水平地流向尾水。考虑结构因素，在尾水管的水平部分设置了一个或两个垂直支墩。任何尾水管的基本尺寸都是高度h。很明显，尾水管越高，其性能越好。另一方面，较高的尾水管需要更多的混凝土，由此增加了厂房的成本。基于此，必须在材料经济性和确保能接受的性能之间作出最佳选择，因为太低的尾水管已经被证明没有太多用处。

Empirical relations and experience curves have been developed to make preliminary determinations for Francis turbines draft tube design. The turbine discharge diameter, D3 and specific speed, ns are used as reference parameters for developing the appropriate controlling dimensions according to de Siervo and de Leva(1976). The absolute velocity at the inlet to the draft tube is given by the following equation:

248

??3=8.74+ ????where ??3=water velocity at the draft tube inlet section, m/sec; ????=turbine specific speed.

对于弗朗西斯水轮机尾水管的设计，已经获得了初步确定的试验关系和经验去西安。根据西尔沃和德勒瓦，将水轮机泄流直径D3和比转速ns作为确定合适的控制尺寸的参考参数。尾水管进口处的绝对速度用下式表示：

248

??3=8.74+ ????其中??3=尾水管进口处的水流速度，米/秒； ????=水轮机比转速。

As the specific speed increases, there is a tendency for controlling dimensions to be increased because the amount of kinetic energy within the draft tube relative to the potential energy is larger, but countering that is the higher cost for the civil works to accommodate the larger dimensions. The experience curves tend to indicate that the civil works cost limitations control the relative size at higher values of specific speed.

当比转速增加，控制尺寸有增加的趋势，因为在尾水管内的动能相对于势能变大，但是容纳较大尺寸的土建工程的成本反而更高。经验公式趋于表明，土建工程成本的限制控制着更高比转速度值处的相对尺寸。

12. Synchronous Generators 12. 同步发电机

Converting water energy to electric energy at hydropower plants is possible through the

operation and functioning of electrical generators. The phenomenon of producing an electrical current in a conductor, discovered by Michael Faraday, involves moving a copper coil through a stationary magnetic field or moving a magnet through a copper coil. In the practical generator, an induced voltage is caused by the magnetic field of a rotor sweeping by the coils of the stator. The rotor of an electrical generator in the case of hydropower developments is driven by the rotation of the turbine. Usually, the turbine and generator are directly connected on a common shaft. Most generators used in hydropower developments are alternating current (AC) synchronous generators. These require excitation current which is usually provided by a small auxiliary generator that supplies direct current to create the magnetic field of the rotor.

在水电厂房中，通过发电机的操作和功能可以将水能转换成电能。由米歇尔·法拉第发现的在一个导体产生电流的现象，包括在恒定磁场中移动铜绕组或在铜绕组中移动一个磁铁。在实际的发电机中，由转子上的磁场切割定子上的绕组就产生了一个感应电势。在水电开发中，发电机的转子是由水轮机的转动而驱动的。通常，水轮机和发电机直接在一个普通的轴上直接连接。在水电开发中应用的大多数发电机是交流同步发电机。这些要求通常是由一个小的辅助发电机供给直流电流来创建所述转子的磁场提供励磁电流。

The basic components of generators as used with hydraulic turbines are (1) supporting frame, (2) shaft that transmits the rotating motion of the turbine, (3) exciter, (4) assembly of the built-up rotor, (5) rotor poles, (6)stator and its component coils, (7) stator coil supports, (8) air cooler, (9) thrust bearings for vertical shaft machines, and (10) brake.

用在水轮机上的发电机的基本组成部分是（1）支持框架，（2）传递水轮机转动运动的轴，（3）励磁器，（4）装配式转子支架，（5）转子磁极，（6）定子及其组件绕组，（7）定子绕组支架，（8）空气冷却器，（9）对垂直轴机械的推力轴承，以及（10）闸。

The stator contains the armature in conventional ac generators and consists of windings of coils pressed into slots in a symmetrical pattern. The core of stator is composed of laminated steel sheets to reduce power losses by eddy currents.

常规发电机的定子包括有铁芯和一些列以对称布置方式压进铁芯槽中的绕组。定子的核心由压层钢板组成以减少由涡流造成的电力损失。

The rotor contains the coils that make up the electromagnets or field winding. The windings surround the individual poles that are mounted on structure that makes up a wheel attached to the rotary shaft. If the windings surround each pole in a symmetrical fashion and are wound individually around a pole that extends out from a cylindrical surface, they are termed salient-pole fields.

转子包括组成电磁体或磁场绕组的线圈。绕组围绕在安装于组成附着于转轴的轮毂的结构上。如果绕组对称地围绕着每个磁极，且分别缠绕于从圆柱体表面延伸出来的磁极上，那么它们被称为凸极磁场。

The number of coils, the wire size and number of turns in a coil, and the number of slots in a stator are design considerations by which size and capacity of the generator are varied. These windings may be connected in series or parallel to achieve the desired voltage or current ratings. For actual functioning of the generator, it is then necessary to have twice the number of coils per phase per pair of poles.

线圈的数量、线径和线圈中的匝数，以及定子中的插槽数的设计考虑是根据发电机变化尺寸和容量而定。这些绕组可以是成串联或并联，以获得所需的额定电压或电流。对于发电机的实际功能，每对磁极的每相的绕组数都必须翻倍。

The field winding magnetic circuit and rotor consists of poles that are duplicates of each

other that they are arranged alternately north and south magnetically. A full cycle of alternating current is developed for each pair of magnetic poles swept by the winding, that is, one cycle per two poles. The fixed number of poles is provided in a full circle and must be an even-integer number of poles, because a north pole must exist for each south pole. The following fundamental formula must be met:

??????

120where f=frequency, Hz(=cycles/sec); ????=number of poles; n=speed, rpm.

??=

该励磁绕组磁路和转子由可互相代替的磁极组成，交替排列在南北磁性。每对磁极切割绕组产生的完整周期的交流电，即，每两个磁极一个循环。一个完整周期中提供固定数目的磁极，且该磁极数目必须为偶数，因为每个北极必须对应一个南极。必须满足以下基础公式：

??????

120其中f=频率，赫兹（=圈/秒）；????=磁极数；n=速度，转每分钟。

There are only a limited number of frequencies used for ac power frequencies. The usual ones are 25, 50, 60, and 400Hz. The most common frequency used with hydropower generators in North America is 60 Hz.

对于交流电流仅应用有限的频率。通常的频率是25、50、60和400赫兹。在北美水力发电机所应用的最普遍的频率是60赫兹。

??=

13. Speed Control and Governors（1） 13. 调速与调速器（1）

Much equipment connected to a hydroelectric system is sensitive to frequency variation. Therefore, speed control of the system is a necessity. Regulating the quantity of water admitted to the turbine runner is the usual means of regulating and maintaining a constant speed to drive the generator and to regulate the power output. This is done by operating wicket gates or valves. Such action requires a mechanism to control the wicket gates, which is the governor or governor system. At decreasing load, the speed tends to rise, and the governor has to close the wicket gates to such an extent that the torque created by the turbine equals the torque offered by the electrical load on the generator and the speed returns to the desired synchronous speed. As the wicket gates open, the speed adjustment is lowered and the inherent tendency of the turbine unit is to pick up additional load in response to a decrease in system speed.

很多与水电系统相连的设备都对频率变化很敏感。因此，系统的调速是必需的。调节进入水轮机转轮的水量是调节和维持一个恒定速度以驱动发电机和调节电力输出的通常手段。这是通过操控导水叶或阀门而完成的。这个操作需要一个控制导水叶的机制，也就是调速器和调速器系统。在减少负荷时，速度趋于增加，且调速器不得不调整导水叶使得水轮机产生的扭矩与调速器上电力负荷提供的扭矩相同，并且其速度发过来达到所期望的同步速度。随着导水叶的开启，速度调节器随之降低且水轮机机组的固有趋势是拾起额外负荷以应对系统速度的降低。

The function of the governor is to detect any error in speed between actual and desired values and to effect a change in the turbine output. This is done so that the system load is in equilibrium with the generating unit output at the desired speed.

调速器的功能是检测实际速度与期望值之间的任何错误，且影响水轮机输出的变化。这样做是为了使得系统负荷与机组输出在期望的速度下相平衡。

The governor system of the turbine acts as an opening, closing, and gate-setting mechanism for starting, stopping, and synchronizing the turbine which allows for matching output to the system load to maintain the system frequency and creates the necessary adjustment on Kaplan turbine blade angles for optimum operation at synchronous speed.

水轮机调速系统的作用类似于一个开启、关闭和定位阀门的装置，使水轮机能够开机、关机和保持同步转速运行，维持水轮机负荷与系统负荷之间平衡，确保系统频率稳定。同时，该系统还能调节卡普兰水轮机的叶片转角，从而保证水轮机以同步转速在最优工况下运行。

Governor systems can be classified as either mechanical-hydraulic governors or electro-hydraulic governors. The three elements of operation are (1) the speed-responsive system for detecting changes in speed, (2) the power component for operating the wicket gates, and (3) the stabilizing or compensating element that prevents runaway speed in the turbine and holds the servomotor in fixed position when the turbine output and the generator load are equalized. The servomotor is the oil pressure system and piston arrangement used to operate the wicket gates.

调速器系统可以被划分为机械液压式调速器或电气液压式调速器。操作的三个要素是：（1）检测速度变化的速度响应系统；（2）操作导水叶的电力组件；（3）稳定或补偿元件，当水轮机输出趋于与发电机负荷相等时，防止水轮机中的飞逸转速并在固定位置稳住住接力器。接力器是用于操作导水叶的油压系统和活塞装置。

A mechanical-hydraulic governor is a unit in which a mechanical centrifugal pendulum acts as a sensor. The flyballs of the pendulum move outward with increasing speed and inward with decreasing speed. The movement of the flyballs is transferred by means of a rod and links to the pilot valve of the governor, which in turn operates the servomechanism for changing the position of the wicket gates. In a Kaplan turbine, the propeller blades are controlled by a separate servomotor with a series of cams or a microprocessor to maintain a position relative to the head and gate position. The flyball mechanism does not have power output necessary to move the wicket gates on a hydraulic turbine. The power for moving the wicket gates is normally supplied by a hydraulic system controlled by the flyball action.

机械液压式调速器是一个机械离心飞摆作为传感器的单元。离心飞摆在向外运动时速度增加，在向内运动时速度降低。离心飞摆的运动通过杆的装置传送，且与调速器的引导阀相连。这反过来操作伺服机构以改变导水叶的位置。在卡普兰水轮机中，螺旋桨式叶片收到一个独立的伺服机构控制，其中一系列的凸轮或微处理器维持在相对于水头和闸门位置的位置。离心飞摆机制没有移动水轮机导叶的必需的电力输出。移动导水叶的电力通常由离心飞摆运动控制的液压系统提供。

14. Speed Control and Governors（2） 14. 调速与调速器（2）

The power component of the entire governor system and gate operating system consists of (1) the servomotor, a fluid-pressure-operated piston or pistons to move the wicket gates; (2) the oil pressure supply, which furnishes the power for the action of the servomotor; and (3) a control valve, which regulates oil pressure and flow of oil in the servomotor.

整个调速器系统和闸门操作系统的电力元件包括（1）伺服电动机，一个移动导水叶的流体压力操作的活塞或活塞；（2）油压供给，它为伺服电动机的运动提供电力；和（3）控制阀，它调整伺服电动机中的油压和油的流动。

The sequence of governor operation consists of the action of flyballs, which respond to the speed change and transmit motion through the system of floating levers to the pilot valve. The pilot valve equipped with relay valves causes oil pressure to be transmitted to one side or the other of the servomotor. The action of the piston of the servomotor in turn opens or closes the turbine wicket gates and regulates the flow of water to change the speed.

调速器操作序列包括离心飞摆的运动，它通过浮筒杆系统向先导阀响应速度变化和传递动作。配备配压阀的先导阀引起油压传递到伺服电动机的一边或另一边。伺服电动机活塞的运动反过来开启或关闭水轮机导叶并调节水流以改变速度。

The speed of a turbine will deviate from normal synchronous speed for a certain percentage of load change. The amount of deviation of speed will depend on (1) the time required to alter the flow of the hydraulic oil in the governor system to correspond with action necessitated by the change in load, (2) the amount of flywheel effect of the entire rotating mass of the turbine and generator, and (3) the time required for the water flow to respond to action caused by the change in the turbine operating point.

水轮机的速度会由于一定百分比的负荷变化而偏离正常的同步速度。速度偏离量取决于（1）改变调速器系统中的液压油以响应负荷变化所必需的动作所需的时间，（2）整个水轮机和调速器旋转系统的飞轮影响的数量，以及（3）水流响应由水轮机工况点变化引起的动作所需的时间。

The simple governor and control system is an isochronous governor. The isochronous governor is inherently unstable, and although some stabilization results from the characteristics of the turbine and connected load, these are generally inadequate and an additional means of stabilization effect of the inertia of the water flow in the penstock. The necessary stability is provided by feedback from the servomotor, which, by means of the dashpot, temporarily restores the control valve toward the null position, and dampens the servomotor movements. The dashpot functions with a spring-loaded valve that is mechanically linked to the servomotor and controls from the pilot valve and the flyball mechanism.

简单的调速器和控制系统是一个同步的调速器。该同步调速器本质上并不稳定，且尽管水轮机特性和连接负载之间稳定的结果，这些通常是在压力钢管中水流惯性的稳定影响的不充足和附加方法。伺服电动机提供了稳定性必需的反馈，而这通过缓冲器方法，暂时恢复向空白位置的控制阀，并抑制了伺服电动机的运动。缓冲器的运行要有一个弹簧式阀门，它机械地连接到伺服电动机并控制先导阀和离心飞摆机制。

To control the turbine speed, the governor must sense the system speed and compare it to a standard. In the case of a mechanical governor, the flyball mechanism is driven by a permanent magnet generator (PMG) attached to the generator shaft, or by a potential transformer (PT) so that any change in system speed results in a change in the flywheel mechanism’s position. In an electronic governor, the frequency may be sensed directly from a potential transformer or the output frequency of a speed signal generator (SSG) attached to the generator. The output

frequency is compared to a standard and the difference is processed electronically to drive a transducer-operator control valve.

为了控制水轮机速度，控制器必须感应系统速度并将其与某个标准比较。对于一个机械式调速器，离心飞摆机制是通过与发电机轴永磁发电机所驱动，或者通过一个电压互感器，使得系统速度的任何变化都导致飞轮机构的位置的变化。在一个电子调速器中，可能直接通过压力互感器或者速度信号发生器的输出频率而直接感应频率。将输出频率与某个标准相对比，其差别用电子处理以驱动由转换器操作的控制阀。

15. Auxiliary Equipment 15. 辅助设备

15.1 Oil-handling facilities 15.1供油设备

Present-day hydroelectric plants require a good deal of insulation oil to be poured into transformers and circuit breakers and turbine oil to be used as a working fluid in speed regulation systems and as a lubricant and a coolant for thrust and guide bearings. Basically, the oil-handling system for each grade of oil incorporates three tanks (for fresh, pure, and used oil), a system of headers, and control equipment. The headers are connected to oil-purifying installations which make it possible to purify the oil by pumping it from tank to tank or by circulation within the same tank. For purification, use is commonly made of centrifuges, filter presses, zeolite sieves, or their combinations.

今天水电站需要大量的绝缘油用于倒入变压器和断路器，以及透平油用于速度调节系统中的工作流体，以及作为推力和导向轴承的润滑和冷却剂。基本上，供油系统对每个等级的油都采用三个箱子（新鲜、纯净和使用过的油）、一个集油管系统和控制设备。集油管与油净化设备相连接，这让它可能通过从一个箱子向另一个箱子的泵送或通过在相同箱子之间的循环而净化。对于净化，通常使用离心机、压滤机、费西滤网或其组合。

The oil-handling facilities may be located within the power house (generally, under the erection site) or in an isolated building. Sometimes, the tanks may be placed outdoors.

The convey the oil to the turbo-generators and transformers, oil conduits are laid along the power house.

供油设备可能位于厂房之内（通常在安装位置以下）或在一个独立的建筑物中。有时，箱子也可能放置在户外。

将油输向涡轮发电机和变压器的油管为沿着厂房铺设。

15.2 Air-supply equipment 15.2供气设备

Hydroelectric plants require much compressed air to be supplied under various pressures for quite number of purposes. For instance, the oil-pressure systems of the turbo-generators and air-blast circuit breakers call for compressed air to be delivered under 2 to 6.3 MPa pressure. Also, the air-operated brakes, de-icing facilities, and air-operated tools need compressed air under 0.8 MPa pressure.

水电站由于很多原因须要提供大量的不同压力下的压缩空气。 比如，涡轮发电机的油压系统和空气断路器需要提供在2到6MPa压力之下的压缩空气。同事，风动闸、除冰设施以及风动工具需要在0.8MPa压力以下的压缩空气。

There is a typical air supply system. Here, the sources of high pressure are compressors which provide an ample supply of air under 7MPa pressure in air receivers. The working pressure (4 MPa for the oil-pressure systems, 2 MPa for the air-blast circuit breakers, and 0.8 MPa for the brakes and other consumers) is produced by pressure reduction as the air is passed through electromagnetic relief valves actuated by electric contact pressure gauges when the pressure falls down to 4 and 0.8 MPa in the air receivers and down to 2 MPa in the air-supply line. In the course of pressure reduction, the air is dried, whick is important for the trouble-free operation of the equipment.

有一个典型的供气系统。此处，高压的来源是压缩机，它能够提供储气罐中7MPa压力以下的广泛的空气供应。工作压力（油压系统为4 MPa、空气断路器为2 MPa，制动器和其它使用方为0.8 MPa）是通过空气的降压过程产生的，因为当储气罐中的压力降至4~0.8兆帕和供气管道压力降至2兆帕时，由电接点压力计控制驱动的电磁卸载阀才会动作并输送压缩空气。在压力减小的过程中，空气变干燥，这对于设备的无故障运行很重要。

In some designs, high- and low-pressure circuits are isolated from each other and have compressors of their own.

在一些设计中，高压和低压环路是彼此独立的，且有各自的压缩机。

An isolated air-supply system is generally used to drive the water out of the runner envelope when a turbo-generator is to work as a synchronous compensator. To this end, air compressed in an air receiver is rapidly discharged into the envelope of the runner which rotates at no-load with the wicket gates shut. The air cushion thus created causes the water level to fall, thereby eliminating the losses due to friction between the runner and the water.

一个独立的供气系统通常用于在涡轮发电机要作为同步补偿器工作时，驱动转轮室中的水。为此，储气罐中的压缩空气被迅速地排到转轮的转轮室中，此时转轮在无负荷及导水叶关闭的情况下运转。空气垫因此产生引起水位下降，因此消除了由于转轮和水流之间摩擦而产生的损失。

Sometimes, it may pay to arrange air receivers in metal-lined cavities left in the concrete structure of the power house, or use for this purpose long pipes 1.5 to 3.0m in diameter. 有时，可能要花费于厂房混凝土结构中金属内衬腔内设置储气罐，或者以此目的使用直径为1.5到3米的长管。

15.3 Process water supply 15.3自流供水系统

At major hydropower plants, the total discharge of water for cooling generators, transformers, turbine bearing lubrication, etc. may run into several cubic meters per second. For normal operation, the water pressure should be within 0.3 to 0.5 MPa, so it is not always possible to use a process water supply system in which the water flows by gravity, especially where water is supplied under head. At a low head, the pressure of water is raised by pumps. Where the head exceeds 200 to 250m, pumps are used to take water from the lower pool. At a head of 50 to 250m, use is generally made of water-jet ejectors. With the last-mentioned approach, water supplied under the existing head is passed through an ejector whose diffuser creates a vacuum. Owing to the vacuum, an additional amount of water is drawn in from the lower pool. The water

pressure at the ejector outlet is somewhat lower than at the inlet.

在主要的水电厂房中，用于冷却发电机、变压器、水轮机轴承润滑等的水量可以达到几立方米每秒。对于正常的操作，水压应该在0.3到0.5兆帕之间，所以，用水靠重力流动甚至在水头下供水的自流供水系统通常不可行。在低水头下，水压通过水泵提升。在水头超过200到250米时，用水泵从下游取水。在50到250米的水头下，通常用到喷水的喷射器。通过最后提到的方法，在已存在水头下提供的水通过一个喷射泵，其扩散器引起了真空。由于该真空，要从下游引入一定附加量的水。喷射器出口处的水压在某种程度上低于进口处。

The basic process water supply equipment consists of water intake structures (built in the piers, abutments, or spiral-case walls), filters, pumps (or ejectors), and pipelines conveying the water to the circular headers of the turbo-generators and other consumers. Waste heated water is discharged into the lower pool. Process water supply systems differ in layout from plant to plant. Sometimes, a single pump may be used to deliver water via trunk pipelines to consumers throughout the plant. In alternative designs, and individual turbo-generators may have a water supply system of its own with isolated water intakes and pumps.

基础的自流供水系统设备包括取水建筑物（修建在桥墩、坝肩或螺旋蜗壳壁内）、滤水器、水泵（或喷射泵）以及向水轮发电机和其它用水的供水环管输送水的管道。废弃的热水排入下游。不同的厂房的自流供水系统布置各不相同。有时，单独的水泵可能被用于在整个厂房中通过干管向耗水部分输送水。在备选设计以及单独的水轮发电机中，可能有其独立取水和水泵的供水系统。

15.4 Unwatering system 15.4排水系统

For maintenance and repair, the water passageway through a turbine, which is isolated from the upper and lower pool by bulkhead gates, must be appropriately unwatered. For this purpose, hydroelectric plants are equipped with suitable pumps which can unwater the passageway through a turbine in a mere four hours. The amount of water Vt in the passageway may approximately be found using experience curves. The required pump capacity (in m3s-1) is given by

????+3600????

3600??为了维护和修缮，通过检修闸与上下游隔离的水轮机水流通道必须经过适当的排水。基于此，水电站配备能够在4小时内排出流道内水流的合适的水泵。在流道内的水量Vt可以用经验公式大致求出。所需的水泵容量（单位为立方米每秒）见下式：

????=

????+3600????

3600??Where Vt is the volume of the water passageway through the turbine (m3), T is estimated time of pumping-out (h), and q is the inflow discharge due to seepage through the gate adopted as 0.2*10-3 to 0.5*10-3s-1 per meter run of the gate seal.

其中Vt是通过水轮机水流通道水的体积（立方米），T是估计的抽出时间（小时），且q是由于闸门渗流而流入的流量，采用闸门密封处0.2*10-3 to 0.5*10-3s-1每米。

Multiunit hydropower plants erected on a spread foundation usually have an unwater gallery running through the entire power house. The gallery is connected by pipelines to all the draft tubes into which water is discharged from the spiral cases. The pipelines are closed by hydraulically operated valves or gates placed in a dry gallery. When a turbine needs to be

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unwatered, the valves are opened and the water is discharged into the gallery. As a result, the water level in the passageway rapidly falls, which facilitates the sealing of the gates. When the unwatering gallery is filled full, pumps installed in the power-house abutments are actuated, and the water is discharged into the lower pool.

修建在一个分散基础上的多机组水电站通常有一个贯穿这个厂房的排水廊道。该廊道通过管线与所有的尾水管相连，蜗壳的水排放到尾水管中。水管通过液压操作阀或防止在干燥廊道的闸门来关闭。当需要在水轮机中排水时，打开阀门水即可排入廊道。结果是通道中的水位迅速下降，这有利于闸门的封闭。当排水廊道被排满时，安装在厂房机台的水泵启动，将水排放到下游。

As the water leaves the turbine, the passageway is filled with air coming in through aeration pipes provided in the unwatering gallery. The aeration pipes are brought out above the upper or lower pool level and are designed to handle a maximum air speed of 40 to 50 ms-1.

随着水轮机的水的排出，通道通过排水廊道中提供的通风管进气。通风管位于上游或下游水位以上，并被设计为控制40 to 50 ms-1的最大空气速度。

When the power-house structure is too shallow to accommodate an unwatering gallery, a way out is to use a pipe header or to install pumps in the pits between the turbo-generators to take care of several units at the same time.

当厂房结构太浅而不能容纳一个排水廊道时，一个解决方法是使用管环或在水轮发电机之间的坑槽内安装水泵以同时考虑几台机组。

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