Method for predicting hydraulic transition process characteristics of water supply system with various flow states

Abstract

The invention relates to a hydraulic transition process characteristic prediction method for a water supply system with various flow states. The method is characterized by comprising the following steps: S1, determining a pressure flow section, an open channel flow section and an open and full flow alternating flow section in the water supply system; s2, determining the calculation time step length of each calculation time step in the hydraulic transition process; s3, an open channel flow section and an open and full flow alternating flow section in the water supply system are approximated to be a pressure flow section by adopting a virtual pressure flow state, so that the whole water supply system is converted into an all-pressure water diversion system, and the initial state of the water supply system is solved; s4, performing time stratification on the open channel flow section and the open-full flow alternating flow section according to the determined calculation time step length, and determining the number of time layers needing to be calculated; and S5, calculating the instantaneous state of the water supply system under each calculation time step until all the pressurized water diversion systems reach a stable state, and obtaining the hydraulic characteristics of typical parts in the whole hydraulic transition process. The invention is suitable for water supply systems with various arrangement types.

Description

technical field [0001] The invention relates to a method for predicting the hydraulic transition process characteristics of a water supply system with various fluid states. It is suitable for water supply systems with various layout types. Background technique [0002] At present, in the water supply projects, some adopt the structural arrangement of the pressurized system. Due to the simple structure and low cost of the open channel, the open channel layout will also be adopted for the water supply projects that can use the open channel. For the change of the water intake reservoir or system pressure according to the water supply, Some systems may have some operating conditions that sometimes have pressure and sometimes have no pressure, which will cause some pipelines to produce alternating clear and full flow, especially during the hydraulic transition process, the clear and full alternate flow will be more rapid. For pressurized systems, the characteristic line method i...

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Problems solved by technology

[0003] After a large number of actual engineering tests, there are corresponding prediction analysis calculation methods for the prediction analysis of the hydraulic transition process of simple pressurized flow, open channel flow and open-full alternating flow, and the relevant prediction methods have been verified to have high calculation accuracy and can meet the engineering requirements. However, for water supply systems that contain two or three types of flow patterns in pressurized flow section, open channel flow and open-full alternating flow, the propagation speed of water hammer waves in pressurized pipes and open channels differs by several orders of magnitude , and the boundary types of any connected water supply system are handled in a variety of ways. At present, there is no solution to predict the characteristics of the hydraulic transition process of the entire system.

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