Thunderhead Engineering Forum

Public Forum => PyroSim => Topic started by: aastra56 on April 22, 2014, 05:22:48 am

Title: Layer Zoning Device
Post by: aastra56 on April 22, 2014, 05:22:48 am
I prepare a simulation of a 100MW size fire incident in a road tunnel and I placed 6 "Layer Zoning Devices", every 50m, along the escape route up to exit door.
According to simulation results, the lower zone heights is >1.5m and the lower zone temperatures is <60°C.
My question is if the "escape route" is safe for people ?
Also, can someone explain to me what means the Height of Lower Zone ?
If the Height of the Lower Zone is > 2m, then is safe for the escaped people ?
What is the specifications of a "safe lower zone" concerning smoke, toxic gases and temperature ?
Thanks in advanced.
Title: Re: Layer Zoning Device
Post by: christofer.wickmark on April 27, 2014, 07:00:09 pm
I suggest you use "trees" of visibility and temperature devices over the height of the tunnel in various places, together with slice files for both parameters.
Title: Re: Layer Zoning Device
Post by: Dave McGill on April 28, 2014, 03:20:40 pm
As suggested by Christopher, vertical arrays of devices and slice files are a better way to make measurements. Layer/zone height is an artifact from the days of zone models.  The zone devices were added to the model by the developers very reluctantly. Depending upon the location of the fire and the shape of the tunnel, you may find that the smoke rolls down the walls of the tunnel.

Acceptable thresholds for tenability would be,
> 10 m visibility
< 60 C temp
< .014 mol/mol CO
< 2.5 kW/m^2 radiant heat

Dave