Insulation for cold tanks

[koay9f]

Issue overview

InsulatedTankCalculator.cpp
Line 63
insulationConvCondHeatLoss = insulationOverallCoefficient * tankArea * (input.getSurfaceTemperature() - input.getAmbientTemperature()) / 1e5;

I think the temperature difference needs an fabs in front of it

Kristina still needs to confirm

EDIT: this might be useful for Kristina later