New Feature: Battery Electric Vehicles

[Martin Griffith]

With the increase in interest in Battery Electric Vehicles in underground mines, we've introduced a feature to help model the heat produced. A new type of heat input is available: Electric Vehicle Power

This input works in the same way that the Diesel Power input works, taking the power of the motor as the input and then calculating the heat produced, taking into account the motor efficiency and the amount of moisture produced. 

The default Electric Vehicle Efficiency is 95%. 

For Diesel Power, we have a Water-to-Diesel ratio to determine how much of the heat produced is given off as latent heat. The Ventsim default value of the Water-to-Diesel is 6, which reflects the moisture produced by the fuel burning, but also the increased moisture that results from the operation of the truck; typically a truck will operate in a moist environment, carrying wet rock and churning a wet road. Similarly for an electric vehicle, a significant part  of the heat will be given off as moisture, despite the electric motor producing only sensible heat. 

To reflect this we have another setting, the Electric Vehicle Latent Heat Factor, default value of 50%. This means that half of the heat given off by the truck will be emitted as latent heat. This factor will likely need to be adjusted to reflect mine conditions; a drier mine might reduce the factor, a wetter one increase it. If your model has a lot of electric vehicles and the dry bulb temperatures are too high or low, it could be that this factor needs calibrating. 

So in the case shown in the image, the electric truck of 350 kW power output is working with a 50% utilisation factor, with a motor efficiency of 95 % and a latent heat factor of 50%. Therefore

Average engine output = 50 % of 350 kW = 175 kW

Heat output = 175 kW / 95% = 184.2 kW

Latent heat output = 50% of 184.2  kW = 92.1 kW

Sensible heat output = (100 - 50)% of 184.2  kW = 92.1 kW

More discussion of this calculation can be found here: 

 

If you have any questions on this feature or anything to suggest, please get in touch by replying to this thread or emailing us at Ventsim.

[xiao]

On 6/14/2021 at 6:44 AM, Martin Griffith said:

ll be given off as moistur

Hey there,

i am adding a electric Truck into Heat Presets. I have filled in the cell "Electric Vehicle Power" and defined  efficiency and Latent Heat Factor of the electric motor in the Setting. Is it nessesary to filled in the "Point Sensible" and "Point Latent"? or the software will calculate the Sensible Heat and Latent Heat from the setting?

Thanks.

Xiao 

[DSepulveda]

Dear Xiao

Ventsim will calculate them from the setting. You can always double-check by running a summary in the gallery where you have added your heat source or within the information box in thermodynamics.