How to calculate the fuel consumption of diesel generators?

Many customers consider fuel consumption when buying generators because it is closely related to operating cost. In fact, the fuel consumption calculation method of the diesel generator set is related to fuel consumption rate and electricity load. So before we buy a diesel generator, we should know the fuel consumption of the diesel generator set and how to calculate the fuel consumption of the diesel generator set.

  • Fuel consumption rate
    Different brands of diesel generator sets, the fuel consumption rate is different, the fuel consumption is different. The approximate fuel consumption is 196g/kw.h– 230g/kw.h, depending on the parameters of the diesel engine. For example, the full load fuel consumption rate (g/kwh) of  Cummins NTA855-G1 diesel engine is 204.6. This is a key point to consider when buying a diesel generator set.
  • Load of electricity
    The larger the load is, the larger the fuel consumption is, the smaller the load is, the smaller the relative fuel consumption is.

The fuel consumption told by the generator salesman is mostly 200g/Kw.h, or much lower than the actual fuel consumption of the purchased generator, which makes the buyer more willing to accept the cost of the generator. Here, we introduce how to calculate the fuel consumption of diesel generator to you, hope to be helpful to you. Generally speaking, most diesel generator manufacturers use the parameter g/ Kw.h, which means that the generator unit consumes a kilowatt (kw) an hour of grams (g) of oil, and then will be replaced by liters (L) so that you can know the cost of fuel consumption in an hour. The specific proportion of water and diesel is about 1:0.84-0.86, that is to say, 1L of diesel is about 0.84-0.86 kg /kg, that is, diesel generator fuel consumption algorithm:

Rated power x fuel consumption per hour (g/kw.h)÷0.84(density kg/L)= fuel consumption

Such as: 220kw diesel generator set fuel consumption of 200g/kw.h

Namely: 220×0.2(kg)÷0.84=52(L)

For another example, how many liters of fuel does a 200kW diesel generator set consume in 8 hours? A 200kW generator is approximately matched to a 220KW diesel engine. The fuel consumption of diesel engine is generally 200 g ~300 g/kW/h (depending on different machines, different grades of fuel).

Now calculated at 200g/kW/h:

220 (kW) *0.2 (Kg) *8=352(Kg)
The density of No. 0 diesel is about 0.84 (Kg/L). 320/0.84=419 (L)
Your 200KW diesel generator consumes about 419 litres of fuel in eight hours.
In order to make you know the approximate fuel consumption of the generator set, calculate the operating cost of the generator set; We have calculated the approximate reference value (30kw — 500kw) for you. The calculated fuel consumption of the 30Kw-500kW generator is as follows:

Fuel consumption of 30kw diesel generator set =6.3 kg (kg) =7.8 L

Fuel consumption of 45kw diesel generator set = 9.45kg (kg) = 11.84L (L)

Fuel consumption of 50kw diesel generator set = 10.5kg (kg) =13.1 L

Fuel consumption of 75kw diesel generator set = 15.7kg (kg) = 19.7L (L)

Fuel consumption of 100kw diesel generator set = 21kg (kg) = 26.25l (L)

Fuel consumption of 150kw diesel generator set = 31.5kg (kg) = 39.4L (L)

Fuel consumption of 200kw diesel generator set =40 kg (kg) =50 L (L)

Fuel consumption of 250kw diesel generator set =52.5 kg (kg) =65.6 L

Fuel consumption of 300kw diesel generator set =63 kg (kg) =78.75 L (L)

Fuel consumption of 350kw diesel generator set =73.5 kg (kg) =91.8 L

Fuel consumption of 400kw diesel generator set =84.00 kg (kg) =105.00 L

Fuel consumption of 450kw diesel generator set =94.50 kg (kg) =118.00 L

Fuel consumption of 500kw diesel generator set =105.00 kg (kg) =131.20 L

The above fuel consumption is the estimated fuel consumption value of the generator set made in China and is for reference only. The specific fuel consumption is subject to the parameters of each manufacturer. Gosun recommends you do the following to save fuel when using a diesel generator set:

1. Maintain good valve clearance
This is one of the basic operations of a diesel generator set to save fuel. Improper valve clearance of diesel engines will make intake insufficient, exhaust is not clean, inevitably resulting in diesel engine excess air coefficient is small, resulting in incomplete fuel combustion. The results not only lead to the diesel engine power shortage, black smoke and other operating faults but also significantly increase fuel consumption. Therefore, it is necessary to check the valve backlash regularly.

2. Check whether the diesel engine is leaking oil
The existence of oil leakage or oil leakage in the fuel system will also cause no small fuel loss.

3. Ensure the cylinder assembly
If the cylinder assembly is worn, the cylinder compression pressure is reduced, resulting in a harsh fuel combustion environment, which will be a significant increase in fuel consumption.

4. Avoid small load operation
Many devices have a “big machine with a small load”, which is a waste of energy. In order to increase power and save energy, it is necessary to increase the diesel belt pulley properly and increase the equipment speed when the diesel engine runs at a lower speed.

5. Check the air filter element regularly
Unclean air filter elements will make the intake insufficient, and the result of incorrect valve clearance will also lead to increased fuel consumption of diesel engines, lack of power and other failures.