In this post, we will discuss about the step to choose engine diesel generator set for electricity supply on the plant or project, especially to supply electricity during the project execution. The main issue here is total cost during the operation of the engine. However, the diesel generator set price will be considered but this price won’t affect significantly to total cost at the end.
First, we need engine datasheet from manufacture or you can search online for this datasheet before doing the calculation. The datasheet shall include with: fuel consumption and lubrication oil consumption.
1. Fuel Consumption
This data will help us to define how much the engine will consume it fuel during the operation. Fuel consumption normally in Liter/hour (L/h). If we got this data, it will be easier to continue the calculation. The others unit to define fuel consumption are g/kWh (gram/kilo watt hour) and lb/BHP-hr (pound/break horse power hours). For these last two units, we will need some conversion calculation to be L/h. Following are the conversion calculation:
kW = Full power output of generator
ρ = Diesel Fuel Density
Lb = Pound
BHP = Break Horse Power
ρ = Diesel Fuel Density (0.85 kg/l)
kW = Full load output of generator
2. Lube Oil Consumption.
To calculate lubricating oil consumption, we should know the lube oil consumption from the engine manufacture. The unit of lube oil consumption similar with fuel oil consumption unit, some manufacture give in L/h, others kg/kWh and lb/BHP-hr.
The next step was to define the evaluation period. For example, if you use the diesel engine generator set for project purpose and the project duration 2 years, it mean the evaluation period for the diesel engine generator shall be 2 years, equal to 24 months, equal to, 720 days. Now, define the diesel engine generator set operation during the day, for example the diesel engine generator set purpose to supply the working equipment/tools (i.e. welding, cutting machine, etc.). So, we can assume that the diesel engine generator set will run for 8 hours for a day or 5760 hours for 720 days.
After define the running hour for the engine, now you can calculate how much fuel and lube oil will be used during the running hours and multiply with the fuel and lube oil price.
Fuel Consumption Rate = L/h
Lube Oil Cons Rate = L/h
Engine running hour = 5760 h
Fuel price = USD xx
- On this calculation, engine assume working with full load during running hours
- Working day assume on this calculation is 360 days in a year
- Maintenance cost not considered
- Expensive diesel engine doesn’t mean the total cost will be high, the total price depend on fuel consumption of the engine
- Lower engine fuel consumption rate mean more economical for the total cost.
- Higher rated power of generator will increase the fuel consumption rate
Any discussion regarding this topic, please comment 🙂
– Experience and learning