Page 394 - Materials Chemistry, Second Edition

378 Appendix A Solution of Exercises

2.5

2.0

MJ t −1 km −1 1.5

1.0

0.5

0
0 10 20 30 40 50 60 70 80 90 100
Degree of utilisation %

−1
Figure A.1 Specific energy consumption (MJ t −1 km ) dependent on the degree of utilisa-
tion.

2. Calculate the fuel consumption (in l Diesel) for a distance of 100 km for a truck
loaded with 24 pallets. Assume a linear dependence between the fuel consumption
and the utilisation rate. Finally, derive the specific energy consumption from the fuel
consumption.

Degree of utilisation Load Energy consumption Fuel consumption

0% (empty) 0 t 9.29 MJ km −1 26 l/100 km
100% 25 t 0.50 MJ t −1 km −1 35 l/100 km
Fuel consumption according to figure in exercise: y = 9 × degree of utilisation + 26
74.4% 18.6 t 0.63 MJ t −1 km −1 32.7 l/100 km

Contrary to the fuel consumption (see figure in exercise) there is no linear
dependence between the specific energy consumption and the degree of
utilisation (Figure A.1)!
3. Calculate the fuel consumption (in l Diesel) for a distance of 100 km for a truck
loaded with 24 pallets related to the functional unit.
−1
Diesel consumption (100 km) = 1.9 l fu .