Method for judging arrangement of water diversion surge chamber of long water diversion system hydropower station

Abstract

The invention discloses a method for judging arrangement of water diversion surge chamber of long water diversion system hydropower station comprising the following steps: 1, respectively establishing unary non-constant pipe flow energy equations on an upstream reservoir cross section, a water turbine inlet cross section and a downstream tail water channel cross section, and combining a water turbine working head equation to obtain a rigid water attack equation considering the head loss of the water diversion system of the hydropower station; 2, combining the approximate boundary conditions of the water turbine, and obtaining a flow-guide vane opening relational expression q = q (phi) considering the head loss of the water conveying system through series treatment; step 3, obtaining a function relationship xis = f (phi) between the maximum water hammer pressure rise rate xis at the tail end of the volute and the relative opening degree phi of the guide vane through item shifting, wherein the function relationship comprises the influence of the hydraulic loss of the water diversion system; 4, calculating and obtaining an allowable value [TW] of a water flow inertia time constant of the water diversion system; and 5, forming a condition for judging whether the water diversion surge chamber is arranged or not. According to the method, the dynamic head loss of the water diversion system of the hydropower station is considered as the judgment condition, and the method is theoretically more perfect and reasonable.

Description

technical field [0001] The invention belongs to the technical field of hydraulic design, and specifically relates to a method for discriminating the setting of a water diversion surge chamber of a hydropower station in a long water diversion system. Under certain circumstances, determine whether it is necessary to set up a water diversion surge chamber to guide the preliminary design of the project, speed up the project progress, and reduce the project cost. Background technique [0002] Due to the limitation of terrain and geological conditions, hydropower stations sometimes need to set up long pressure diversion pipes, which makes the water flow inertia of the diversion system larger. When the load of the power station changes, water hammer occurs in the water diversion system, and the longer the channel, the greater the water hammer pressure, which can lead to pipe burst and structural damage to the unit in severe cases. Setting up a water diversion surge chamber is the ...

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Problems solved by technology

[0028] Through the analysis, it can be seen that the above two types of discrimination conditions have neglected the influence of the water head loss of the water diversion system on the setting of the water diversion surge chamber

When the pipeline of the water diversion system of the hydropower station is long, especially for the pressurized diversion hydropower station with a long water diversion system, the head loss of the water diversion system is relatively large, and ignoring the head loss may cause a large error

Not only that, [T W ] has a wide range of values, and it is easy to appear T W It is difficult to determine whether to install a water diversion surge chamber if the value is within 2-4s; and according to engineering practice, there is a power station T W The value is less than 2s, but after the calculation of the hydraulic transition process and detailed technical and economic comparisons, the selection of the installation of the diversion surge chamber has brought difficulties to the preliminary design of the hydropower station

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