论文部分内容阅读
压力管道的流速、水头损失、造价和运行、施工、维修等费用都取决于管道直径。由于引水径流式电站中,其河流流量频率曲线往往较陡,而电站本身又无调节能力,按天然流量发电。因此,在引水径流式小型水电站中,一年中约有2/3的时间,河流流量小于电站装机容量所需的发电流量;约有1/3的时间,河流流量大于电站装机容量所需的发电流量。另外,渠道设计一般按均匀流计算,且渠道过水能力留有一定的余量,按渠道水力特性确定的最大过水能力均大于装机容量所需的发电流量。针对这一特点,在河流流量大于电站装机容量所需要的发电流量的时间内,我们通过加大流量来弥补由于缩小管径所增加的水头损失,从而保持出力不变。这样在一部分时间内增加发电流量使得出力不变,充分利用渠道的安全余量;而在另一部分时间内所增加的水头损失又不多,但缩小管径之后,所节省的工程投资、贷款利息和年运行、维修等费用远大于这部分时间所增加的水头损失而对应的电能经济损失。
Pressure pipe flow, head loss, cost and operation, construction, maintenance and other costs are dependent on the pipe diameter. As the diversion runoff power station, its river flow frequency curve is often steep, but the power station itself has no regulation capacity, according to the natural flow of power generation. As a result, about two-thirds of the year’s runoff in a small-scale runoff diversion hydropower station is less than the required generation capacity of the plant; about one-third of the time, the river flow is greater than the required capacity of the plant Power flow. In addition, the channel design is generally calculated according to a uniform flow, and the passage of water capacity to leave a certain margin, according to the channel to determine the maximum hydraulic properties of water capacity is greater than the installed capacity of the required power flow. In response to this feature, we maintain the output unchanged by increasing the flow rate to compensate for the increased head loss due to the reduced tube diameter, while the river flow is greater than the generation flow required by the plant’s installed capacity. In this way, the power generation flow will be increased in a part of time so that the output will be kept unchanged and the safety margin of the channel will be fully utilized. However, the additional head loss will not increase much in other time. However, after the diameter reduction, the project investment and loan interest And the annual operation, maintenance and other costs far greater than this part of the increase in head loss corresponding to the economic loss of electricity.