更优良的圆锥导水机构.doc

更优良的圆锥导水机构
灯泡贯流机组的发电机装置在水轮机流道中的灯泡形壳体内，采用直锥扩散形尾水管，流道短而平直对称，水流特性好。大型贯流机组几乎都是灯泡机组，中小型多采用轴伸式、竖井式等形式。

Of bulb tubular unit generator system in water turbine runner bulb-shaped casing, which adopts straight taper diffusion form draft tube, runner is short and straight is symmetrical, flow well. Large tubular units are almost all bulb units, more than small and medium in the form of shaft extension type, shaft type, etc.

贯流式水轮机的流道形式和轴流式水轮机不同，为保证向导水机构均匀供水和形成必要的环量，保证导叶较平滑绕流，轴流式水轮机需设置蜗壳，其流道由蜗壳、导水机构和弯肘型尾水管组成。贯流式水轮机没有蜗壳，流道由圆锥形导水机构和直锥扩散形或S型尾水管组成。通常采用卧轴式布置，从流道进口到尾水管出口，水流沿轴向几乎呈直线流动，避免了水流拐弯形成的流速分布不均导致的水流损失和流态变坏，水流平顺，水力损失小，尾水管恢复性能好，水力效率高。

Tubular turbine flow form and axial flow turbine, in order to ensure the guide uniform water supply and water institutions form necessary circulation, ensure guide blade is smooth flow, axial flow turbine volute, for its passage by the spiral case and guide water agencies and bending of draft tube elbow type. Tubular turbine spiral case, port by conical guide water agencies and straight taper diffusion of shape or S tail pipes. Usually adopted horizontal spindle type is decorated, imports from runner to tail pipe outlet, water flow along the axial flow almost in a straight line, curve formed to avoid the water flow velocity distribution in flow losses and the flow pattern worse, smooth flow, hydraulic loss is small, the tail pipe recovery performance is good, high hydraulic efficiency.

贯流式水轮机单位过流量大，转速高，水轮机效率高，且高效区宽，加权平均效率也较高，具有比轴流式水轮机更优良的能量特性。其特征参数比转速ns、可达1000以上，比速系数可达3000以上。与轴流式水轮机相比，在相同水头和相同单机容量时，土工格栅厂家其机组尺寸小，重量轻，材料消耗少，机组造价低。贯流机组电站还可获得年发电量的增加。

Tubular turbine units of large flow, high rotating speed and turbine efficiency is high, and high efficient area wide, the weighted average efficiency is also higher, more excellent than axial flow turbine energy characteristics. Its characteristic parameters than ns speed, can reach more than 1000, specific speed coefficient can reach more than 3000. Compared with the axial flow turbine, when the same head and single machine capacity, the unit size is small, light weight, less material consumption, low unit cost. Tubular unit in power plant can also be increased capacity.

贯流式水轮机的空化性能和运行稳定性也优于轴流式水轮机，其空化系数相对较小，机组可靠性高，运行故障率低，可用率高，检修时间缩短，检修周期延长。对于低水头资源开发，钢塑土工格栅贯流式水轮机的稳定运行范围宽，在极低水头时也能稳定运行(如超低水头1.5m以下)，是其他类型的水轮机不可比的。如广东白垢电站，额定水头6.2m，最大水头10.0m，但在1.3m水头时仍能稳定运行。

Tubular turbine cavitation performance and stability also is better than that of axial flow turbine, the cavitation coefficient is relatively small, for its high reliability, running low failure rate, high availability, shorten maintenance time, maintenance cycle is extended. For low head water resources development, the stable operation of a wide range of tubular turbine, can stable operation at extremely low water head (e.g., low head below 1.5 m), is than other types of water turbine. White scale power stations such as guangdong, rated head is 6.2 m, the maximum water head is 10.0 m, but still can run stable when 1.3 m head of water.