Explanation Of TNO Model
The TNO model is a velocity and payload dependent emission model for heavy-duty road freight transportation.
This model uses a regression model. Some explanatory factors for this model are the GVW, denoted by M, and the payload, denoted by m, both of which are in tons, as well as the speed in km/h, denoted by V. These variables can be seen using model/equation 1.
This model first computes EM as a function of 8 parameters and V: in emissions per tons. The parameter estimates are seen in Table 1 to the left.
The results are then multiplied by M to obtain the final result which is the emissions of the empty and full vehicle.
Additionally, you can measure the energy use in kW per ton, which is denoted by the term kW t. This term depends on m and M and can be found using equation 2.
These computations can be used for a series of different results, but they are mainly considered for the 8 classes of vehicles, which can be seen in table 2.
The different average speeds are also considered as they vary from 10 to 80 km/h.
For each average speed and truck, two numbers are computed: the carbon emissions of the empty and of the full truck. The relationship presented between these two numbers is linear
Model/Equation 1
This equation is the basic TNO model, and it takes inputs including the grams per kilometre by ton of nitrous dioxide, hydrogen chloride, carbon monoxide, nitrous monoxide, and carbon dioxide, and it multiples this by the velocity and by the energy use per ton in order to give the emissions of the truck.
Table 1 (Parameters Of The Emission Model)
g/km x ton | A | B | C | D | a | b | c | d |
|---|---|---|---|---|---|---|---|---|
NO2 | 0.08922 | -0.003092 | 0.00004439 | -0.00000004167 | -0.02214 | -0.0001176 | 0.000007771 | -0.00000008317 |
HC | 0.2127 | -0.001918 | 0.000005532 | 0.00000003170 | -0.004419 | 0.0001150 | 0.000001659 | -0.00000002507 |
CO | 15.683 | -0.3136 | 0.001208 | 0.000003042 | -0.3344 | 0.01186 | 0.00001886 | -0.0000007911 |
NOx | 7.909 | -0.3871 | 0.0004301 | 0.00003087 | 0.4824 | 0.01997 | 0.0004515 | -0.000006870 |
CO2 | 465.390 | 32.389 | -0.4771 | 0.0008889 | 48.143 | 0.8931 | -0.02559 | 0.0004055 |
This table gives the parameters that are used within the emission model. It includes are of the gases that are measured in the model, including nitrous dioxide, hydrogen chloride, carbon monoxide, nitrous monoxide, and carbon dioxide, and it gives the grams per kilometre by ton of all of these gases.
Equation 2
This second equation is used to calculate the specific power of the vehicle used to calculate emissions. This equation takes inputs of the gross vehicle weight and the payload and uses this to give the specific power in kilowatts per ton. This specific power is the plugged back into the first equation to calculate the emissions.
Table 2 (Vehicle Classes And Capacities According To The National Academy of Sciences)
Vehicle Class | GVW | Payload Capacity | Example |
|---|---|---|---|
3 | 5 to 7 t | 37.5% | Vans |
4 | 7 to 8 t | 44.4% | City/Parcel Delivery |
5 | 8 to 9.75 t | 44.4% | City/Parcel Delivery |
6 | 9.75 to 13 t | 55.6% | City/Parcel Delivery |
7 | 13 to 16.5 t | 55.6% | Furniture, Refrigerator |
8 | 16.5 to 40 t | 66.7% | Tractor Trailer |
This table gives the vehicle class, gross vehicular weight and payload capacity for 6 different vehicle classes. This information on payload capacity and gross vehicular weight is used for calculating emissions for these vehicles.