Modelling a production drill

[Laura]

Hello,

I would like some advice as to how to model a production/face drill to simulate both the heat and water addition within the mine. Assuming that the drill specification is 65kW electrical power and uses 60l/m water I have set the sensible heat attribute to 65kW and the point Moisture to be 1000ml/sec in the 'Heat Moisture Diesel' presets . I have ignored the diesel parameters as they would only be used during tramming. I then rerun the simulation and look at the New Heat showing 65kW and New Sensible Heat parameter and it is showing 76.8kW so far so good I think.

My question is a) Is this the correct way of modelling this drill? b) How can I view the water that has been added to the model? What is the best variable to inspect?

Thanks in advance,

Laura

[Martin Griffith]

Hi, 

Thanks for your questions.

a/ I think this is the correct way to model the drill. However, you need to check where the moisture and energy is going. Is there 1000ml/sec of water being evaporated into the air, or is there some amount which runs off in a drain or channel? The value you enter here should be what is evaporated in the air. 

b, c/ There is no property available which tells you how much moisture is being added, other than where you've input it. But you can see the effect in the results. You will see the dry bulb temperature immediately downstream of the moisture source go down as you add more moisture. If you add enough moisture, the air will be saturated (dry bulb = wet bulb) and Ventsim will calculate how much fog and condensate forms from the saturated air. The New Sensible Heat parameter is not much use here, as it includes heat transfer from the rock wall. 

I hope this helps, let us know if you have more questions.

 

[Craig Stewart]

Another way to calibrate a drill machine is to use the HEAT CALCULATOR tool in Ventsim.  If you can physically measure the airflow and temperature of the air going in and out of the job, you can enter the result in the HEAT CALCULATOR and it will report the amount of sensible heat and moisture to add.  Just a caution though - some of this heat may be from surrounding rock, so keep the measurement of in and out airflow short.