卓越班英语

In storage reservoir，the flood downstream can be better controlled and regulated properly so as not to cause their coincidence.

应用蓄水库可以控制和调整下游的洪峰，使这些洪峰不同时出现。

Arch dams transfer the greater proportion of the water load to the valley sides rather than to the floor.拱坝传给两侧岩石的水压力远远大于传给底板的水压力。

The most economical type of dam will often be the one for which materials are to be found in sufficient quantity within a reasonable distance from the site.

最经济的坝型应该是在距离坝址合适的距离有足够的数量的建坝材料。

Hydroplants may be classified on the basis of hydraulic characteristic as fllow: run-off river plants, storage plants,pumped storage plants, tidal plants.根据水力特性把水力发电站分为下列几种：径流式电站、蓄水式电站、抽水蓄能电站、潮汐电站。

2.During peak hours，the water flows from the reservoir to the turbine and electricity is generated.During off-peak hours,the excess power is available from some other plant,and is utilized for pumping water from the tail pool to the head pool, this minor plant thus supplements the power of another major plan.In such a scheme,the same water is utilized again and again and no water is wasted.

在峰荷期间，水从水库流入水轮机而产生电能。在非峰荷期间，利用其他电站的剩余电能，从尾水池抽水到前池，因而这个较小的电站为另一个较大的电站补充电能。在这样的系统中，同样的水量被一次又一次的重复利用，而没有被浪费。

Electric power is generated in power generating stations or plants.

电能是在发电站或发电厂产生的。

The capacity of individual generators is larger and larger to satisfy the increasing demand of electric power.

单台发电机的容量越来越大，目的就是满足不断增长的用电需求。

．Although the energy delivered to an impulse turbine is all kinetic,while the reaction turbine utilizes pressure energy as well as kinetic energy,the action of both turbine depends on a change in the momentum of the water so that a dynamic force is exerted on the rotating element,or runner.

虽然传输到冲击式水轮机的能量都是动能，而反击式水轮机利用的能量是压能和动能，但是这两种类型的水轮机能量都是靠水的动量变化的动力作用于旋转的转子产生的。

The water being under pressure，the entire flow from head race to tail race takes place in a closed conduit system and the atmospheric air has no access at any point. 水在水头压力作用下，在引水管到尾水管形成的水流处于一个完全封闭的管路系统，连一丝空气也无法跑出。

Any location that produces asymmetrical flow into the pump bays causes problems with circulation, uneven velocity distribution, vortices, and generally poor pump

performance.

泵站的位置如果使得不均匀的水流流入泵壳中将导致水循环、不均匀的流速分布、漩涡，以及水泵不能正常运转。

2. The greater the number of pumps , the smaller the reduction of the total station capacity if one pump malfunctions.

泵站的数量越多，一个泵站出现故障对整个泵站容量的减少越小。

In power stations, coal or oil is burned and changed into electricity, which is then sent over to homes and factories.

在发电站里，煤和石油燃烧变成电，然后电沿导线输送到住家和工厂。

A concentrated-fall hydroelectric development is one in which the station is located near the dam and is more common for low-head installation.

集中落差水力发电开发工程的发电厂位置接近坝身，该工程在低水头情况下应用较为普遍。

2. If there is no outspoken drop of the river bottom at the dam site, the height of the dam will be of the same order of magnitude as available head of the station.

如果在坝址河底没有明显的陡坡，则大坝高度与电厂的有效水头为同一数量级。

3. If there is a significant but gradual drop in the river bottom, the situation may lend itself to a variety of solutions.

如果河底下降相当大单坡度较缓，这种情况适合作出许多不同布局。

The speed of a generator is controlled by the prime mover.

发电机的转速受原动机控制。

A distribution reservoir is a small storage reservoir constructed within a city water supply system. Such a reservoir can be filled by pumping water at a certain rate and can be used to supply water even at rates higher than the inflow rate during periods of maximum demands (called critical periods of demand). Such reservoirs are, therefore, helpful in permitting the pumps or water treatment plants to work at a uniform rate, and they store water during the hours of no demand or less demand and supply water from their “stora

ge” during the critical periods of maximum demand.

配水水库是小型蓄水水库，建在城市供水系统内。这样的水库按一定的流量用抽水的方式注满，在需水量最大的时期（称为临界需水期），它的供水流量甚至大于水库的入流量。因此，这样的水库可以使水泵或水处理厂以均匀的流量进行工作，在不用水或很少用水的时期，配水水库就蓄存水量；在最大蓄水临界期，它就从“仓库”里供水。

A dam must be relatively impervious to water and capable of resisting the forces acting on it. The most important of these forces are gravity (weight of dam), hydrostatic pressure, uplift, ice pressure, and earthquake forces. These forces are transmitted to the foundation and abutments of the dam, which react against the dam with an equal and opposite forces, the foundation reaction. The effect of hydrostatic pressure caused by sediment deposits in the reservoir and of dynamic forces caused by water flowing over the dam may require consideration in special cases. 坝必须