1 Reply Latest reply on Jun 28, 2012 10:24 AM by Dan Hofstetter

    problems with fan concentration settings

    Dan Hofstetter

      I have been having some trouble with internal fans recently.  I have a model where the initial concentrations are defined by a F(z) table:

       

      ZH2S ppmZAir ppm
      0156.90999843
      1.83156.91.83999843
      1.83101.8311.00E+06
      5.4905.491.00E+06

       

      The internal fan is placed at the horizontal boundary between these two concentration levels, the inlet is on the air side, and the outlet is on the H2S side.  I have not built the flow simulation configuration from scratch too many times, so I'm not sure of the correct order, but it seems that if I define the internal fan first, and then the F(z) initial conditions, everything plays nicely and the simulation works.  If I defined the initial conditions first, then each time I set up a new internal fan, Flow Sim seems to grab the initial concentration data and use it for the fan output.  So when I run the simulation, the fan essentially blows 156.9 ppm H2S into the tank constantly.  I have not found a good way to fix this other than clearing the Flow Sim configuration and rebuilding the config from scratch.

       

      Has anyone else noticed this?  I'd call it a bug, but maybe this is common.  I am using SW 2011 SP5.0.