2.5 conduit are designed
2.5.1 hydraulics are calculated
When undertaking conduit hydraulics analyses computation, study phenomenon of hammer of head loss, water mainly. Hydraulic computation uses this second glass steel tube " glass reinforced plastics adds arenaceous conduit " the formulary computation of intermediary carry on, calculate first namely Reynolds number, undertake judging according to formula next, it is to belong to hydraulic and smooth area, still be coarse area, still be area of mixed film friction, by different formulary computation hydraulic slope falls finally and head loss.
① node discharge and tubal Duan Liu measure computation: The line form that grows along canal line by discharge of water supply section distributings have consideration, be in charge of paragraph of discharge to be equal to the discharge that pours out of node to have consideration according to the discharge of inpour node.
Basic hydraulics calculates ② conduit: The current inside this project canal flows for pressure valve, its cross water ability to have consideration by pressure conduit formula: Q= μ ω (2gz) 1/2, the Q in type, pass discharge (M3/s) , ω , area of section crossing water (M2) , z, water level of imports and exports is poor, namely loss of total peak of flow (M) , μ , capacity coefficient, with Cheng of the edge inside the canal attrition loss and local resistance loss are concerned. The most crucial parameter is parameter of first class of tubal diameter, total water, after make choice of provides material one kind, coarse rate is firm, try diameter calculating a canal, velocity of flow, till get right tubal way, velocity of flow.

Coefficient of surface roughness of ③ Reynolds number, equivalent, hydraulic frictional resistance calculates: Concern surface roughness of number of formulary computation Reynolds, equivalent by hydraulics, according to position of flow of differentiate of surface roughness of Reynolds number, equivalent, choose different formula to calculate coefficient of hydraulic frictional resistance
④ computation is hydraulic slope falls: Conduit is hydraulic slope falls computation presses formula of pressure conduit computation to have consideration, namely J= λ / D* (V2/(2g) ) , j, conduit is hydraulic slope falls, λ , conduit is hydraulic frictional resistance coefficient, d, tubal diameter (M) , v, the velocity of flow inside the canal (M/s) , g, gravitational acceleration (M/s2) .
Loss of ⑤ conduit head calculates: Loss of conduit total peak of flow is loss of edge Cheng head and the sum of local head loss, the conduit that is in charge of loss of paragraph of edge Cheng head to go out by computation is hydraulic slope falls computation, the appraise at the beginning of local head loss is losing of edge Cheng head 10% , wait for cop to decorate detailed computation waits according to valve, bend again after finishing.
⑥ conduit is hydraulic computation: The control freedom according to node of the most adverse water supply is hydraulic take 10.0m plan, freedom is hydraulic subtract for hydraulic elevation ground level, hydraulic elevation should be nodded to fountainhead from node of the most adverse water supply or water supply nods computation. Run safety plan for the project, conduit of total water supply is hydraulic by each paragraphs dead water pressing chooses conduit, close check valve downstream when conduit namely when, what form by place of pumping station pump up water is the biggest hydraulic.
Previous12 Next