Tunnel Ventilation 1

[shawngt2]

Hello everyone,

I have a general question regarding heat transfer, as I have no recent experience with this. I work in the Tunnel Boring Business and within a tunnel boring machine (TBM) heat is generated during mining. Electrical and hydraulic motors within the TBM generate heat which is calculated and an appropriatly sized water cooling system is designed to remove most of the heat.

Since water cooling does not move 100% of the heat (actual value unknown) we are estimating 50% effective heat removal from the water system and the remaining transfering into the TBM work area. The work area is the end of a tunnel where air is delivered via ventilation piping.

Here are my knowns;

- 7,325 Watt/hr generated in the TBM from equipment(after water cooling).
- 68,400 m^3/hr air delivered at 30°C.

How could you estimate the theoretical temperature of the working environment? Which formulas?

I would assume there are other factors involved like air humidity, density, etc...?

ANY help would be appreciated!

Kind Regards,

Shawn

 

[MintJulep]

For starters, watt/hr is not a unit of power or energy.

 

[shawngt2]

7,325 Watt-hr?

 

[chicopee]

Well use Q=(dM/dt)*Cp*DT. You already know Q in watts; dM/dt being the mass flow rate of the air which you will need to estimate as a bulk value based on the given CuM/Hr and an average moist air density; Cp being the specific heat of moist air; DT=Tf-Ti being the temperature difference of the moist air. So you calculate for Tf.