MortenA
Chemical
- Aug 20, 2001
- 2,998
A consultant has performed some work for us on a fire water system using pipenet. I have myself done many such simulations using a tool that seems very similar (Flowmaster). They are both single phase, both allow "priming" by allowing the user to specify certain parts of the network initially "dry" (gas filled) that during the simulation becomes "wet" but the "transformation" can only happens once and not from wet to dry.
So how does the vacuum breaker/air valve work? Im quite sure that for Flowmaster it "assumed" that the air "remained" within the vacuum breaker component so you wouldnt get an actual "air cushion" in the pipe where you had your VB sitting, but it could calculate the air volume having entered and exited and also a corresponding pressure increase. This should be sufficient as long as your pipe is vertical and dosnt branch. Does pipenet work in a similar fashion? Im not quite sure how flow was handled - say if pressure permitted flow across the node but all the air was not expelled from the VB (see sketch attached) - so my question is: Does the VB component somehow prevent flow of water across the node until the air is expelled?
So how does the vacuum breaker/air valve work? Im quite sure that for Flowmaster it "assumed" that the air "remained" within the vacuum breaker component so you wouldnt get an actual "air cushion" in the pipe where you had your VB sitting, but it could calculate the air volume having entered and exited and also a corresponding pressure increase. This should be sufficient as long as your pipe is vertical and dosnt branch. Does pipenet work in a similar fashion? Im not quite sure how flow was handled - say if pressure permitted flow across the node but all the air was not expelled from the VB (see sketch attached) - so my question is: Does the VB component somehow prevent flow of water across the node until the air is expelled?