g/kwh to gal/h

[A+ Ano]

I am trying to compare fuel consumption ratings on Diesel electric generators
The american ones show gals per hour of consumption at 50% load 75% load & 100% load which is what I am familiar with.
All the other generator sets are rated by g/kwh which I think is grams per Kilowatt hour?
What I'm having trouble with is a gram is a weight not a volume? Do I multiply the total kilowatt hours which in this case is 60kw x the grams per hour(in this case 230) 60x230=13,800 grams
Do I have to figure out what a gal of diesel fuel wieghs? and the convert the grams to weight?

Any help would be great.
Thanks A+

[Robert Fogt]

I found a chart that lists diesel fuel oil 20 to 60 at 15º C as having a density between 820 and 950 kilograms/cubic meter (which is the same as gram/liter).

If you know how many grams of fuel you have:
grams / 820 gram/liter = liters

If you know how many liters of fuel you have:
liters * 820 gram/liter = grams

Now just convert liters to gallons, or gallons to liters first.
1 gallon [US, liquid] = 3.7854118 liter

Also you may wish to use a mid value between 820 and 950 for the density, or work the formula out for both 820 and 950 to get the range.

[quay_crane@yahoo.com]

I would to convert a 213 g/kwh to l/h

[duck]

i would like to know how to convert from g/kWh to l/h ?? must i change it to other forms before i could proceed to liter/hour..??

thank you so much

[JohnS]

I found a chart that lists diesel fuel oil 20 to 60 at 15º C as having a density between 820 and 950 kilograms/cubic meter (which is the same as gram/liter).

If you know how many grams of fuel you have:
grams / 820 gram/liter = liters

If you know how many liters of fuel you have:
liters * 820 gram/liter = grams

Now just convert liters to gallons, or gallons to liters first.
1 gallon [US, liquid] = 3.7854118 liter

Also you may wish to use a mid value between 820 and 950 for the density, or work the formula out for both 820 and 950 to get the range.

I think that range is combining diesel and fuel oil. 950 g/L is a pretty heavy fuel oil, needs heating to keep it flowing. #1 diesel (winter) would be at the low end of your range, maybe even a little lower, #2 diesel maybe 0.83-0.85, There is lot and refinery variation

[JohnS]

I am trying to compare fuel consumption ratings on Diesel electric generators
The american ones show gals per hour of consumption at 50% load 75% load & 100% load which is what I am familiar with.
All the other generator sets are rated by g/kwh which I think is grams per Kilowatt hour?
What I'm having trouble with is a gram is a weight not a volume? Do I multiply the total kilowatt hours which in this case is 60kw x the grams per hour(in this case 230) 60x230=13,800 grams
Do I have to figure out what a gal of diesel fuel wieghs? and the convert the grams to weight?

Any help would be great.
Thanks A+

Yes, you have two units problems. One is grams and gallons. Diesel has a density around 850 g/L. Divide by the grams by this figure to get liters, then 3.7854 L/gal to get gallons.

To compare to the other figures, you have to multiply the g/kWh figure by the number of kWh, and it has to correspond with the stated load for the generator you are comparing to.

The other way might be to convert the US generators to g/kWh figures. To do that, convert gallons to liters, then to grams using density. Divide by the kWh load corresponding to that stated fuel consumption.

[Unregistered]

help me! covert g/kw.h to l(diezel)/h:

[Indian Guest]

I found a chart that lists diesel fuel oil 20 to 60 at 15º C as having a density between 820 and 950 kilograms/cubic meter (which is the same as gram/liter).

If you know how many grams of fuel you have:
grams / 820 gram/liter = liters

If you know how many liters of fuel you have:
liters * 820 gram/liter = grams

Now just convert liters to gallons, or gallons to liters first.
1 gallon [US, liquid] = 3.7854118 liter

Also you may wish to use a mid value between 820 and 950 for the density, or work the formula out for both 820 and 950 to get the range.

The data that I have is

Fuel consumption at full load: appr. 213 [g/kWh]

Now : How much fuel is the equipment actually consuming per hour ?

For your info : It is an AC Generator designed to give 200 V AC power @ 400 HZ frequency and power Factor of 180 KVA.

[euphoria_82]

I found a chart that lists diesel fuel oil 20 to 60 at 15º C as having a density between 820 and 950 kilograms/cubic meter (which is the same as gram/liter).

If you know how many grams of fuel you have:
grams / 820 gram/liter = liters

If you know how many liters of fuel you have:
liters * 820 gram/liter = grams

Now just convert liters to gallons, or gallons to liters first.
1 gallon [US, liquid] = 3.7854118 liter

Also you may wish to use a mid value between 820 and 950 for the density, or work the formula out for both 820 and 950 to get the range.

Fuel consumption at full load: appr. 213 [g/kWh]

Now...what will be amount of fuel consumed per hour ?

This is for a 180 KVA generator supplying 200 V AC @ 400 HZ .

Please help me sort this out :)

[JohnS]

Fuel consumption at full load: appr. 213 [g/kWh]

Now...what will be amount of fuel consumed per hour ?

This is for a 180 KVA generator supplying 200 V AC @ 400 HZ .

Please help me sort this out :)

Lets avoid issues of the "power factor" of the load, and assume power factor is 1, so 180 KVA = 180 kW.

213 g/kWh x 180 kW = 38340 g/h or 38.340 kg/h
A liter of diesel fuel is about 0.85 kg, so 45.1 L/h or 11.9 US gallons per hour at full load. If generator is not putting out full load, consumption will be less, but not linearly with load (it still consumes fuel just to spin, even if no load is connected.)

[euphoria_82]

Lets avoid issues of the "power factor" of the load, and assume power factor is 1, so 180 KVA = 180 kW.

213 g/kWh x 180 kW = 38340 g/h or 38.340 kg/h
A liter of diesel fuel is about 0.85 kg, so 45.1 L/h or 11.9 US gallons per hour at full load. If generator is not putting out full load, consumption will be less, but not linearly with load (it still consumes fuel just to spin, even if no load is connected.)

Thanks a lot John..You made it really simple.

I applied the same logic to calculate the consumption for a Air Conditioning Unit (115 Tons) that had "Specific fuel consumption at maximum torque : 200 g/KWh.". Here the output of the engine was expressed in BHP. I simply converted BHP to KW (Mulitplied BHP by 0.7457 to get KW) and then got the calculation done as you mentioned :)

Thanks all the way from India :)

[Unregistered]

Dear A+,

I had to do the conversion this moring for myself. Back to basics.
I used info available at various conversion sites and please feel free to check my figures.

1 gram = .0001 Kg
1 Kg = 2.2046 lbs
7.2 lbs = 1 gallon of diesel

1 gram or .001 Kg x 2.2046 lbs/Kg = .0022046 lbs.
.0022046 lbs x 1 gal /7.2 lbs = .000306 gallon

So 1 gram = .000306 gallon

Your consumption is given in g/kWh and you want gal/kWh so the only thing that changes is from

So let's take a consumption of 211 g/kWh x .000306 gallon = .064566 gallon and your genset is rated at 180 kW = 11.62 gallons per hour


Hopes this helps


I am trying to compare fuel consumption ratings on Diesel electric generators
The american ones show gals per hour of consumption at 50% load 75% load & 100% load which is what I am familiar with.
All the other generator sets are rated by g/kwh which I think is grams per Kilowatt hour?
What I'm having trouble with is a gram is a weight not a volume? Do I multiply the total kilowatt hours which in this case is 60kw x the grams per hour(in this case 230) 60x230=13,800 grams
Do I have to figure out what a gal of diesel fuel wieghs? and the convert the grams to weight?

Any help would be great.
Thanks A+

[Unregistered]

Rated Power kva 20
Max power kva 22.5
PHASE three
Frequency (HZ) 50HZ
Rated voltage (V) 220～240/110～120；400/230V
Rated Current (A) 34.7A
Bore*Stroke 100x115
Displacement(L) 3.61
12h Power kw(ps) 26.5
Fuel Consumpion g/kw* h 258.4
LUBE CONSUMPTION g/kw h 2.04
Compression ratio 18.0:1

Hi, please help me I need to know what is the fuel consumption in litres for the above specs

[JohnS]

Rated Power kva 20
Max power kva 22.5
PHASE three
Frequency (HZ) 50HZ
Rated voltage (V) 220～240/110～120；400/230V
Rated Current (A) 34.7A
Bore*Stroke 100x115
Displacement(L) 3.61
12h Power kw(ps) 26.5
Fuel Consumpion g/kw* h 258.4
LUBE CONSUMPTION g/kw h 2.04
Compression ratio 18.0:1

Hi, please help me I need to know what is the fuel consumption in litres for the above specs

Lets assume power factor = 1, so rated power is 20 kW. At 20 kW, fuel consumptuion is
20 kW x 258.4 g/kWh = 5168 g/h or 5.168 kg/h
Diesel varies, but 0.84 kg/l is a good typical figure for #2 diesel, so
5.168 kg/h x 1 L/0.84 kg = 6.15 L/h

[Unregistered]

I need to conver 320g/kW.h into L/hr for a diesel generator 13kVa , at 50Hz with an output voltage of 230V.

[JohnS]

I need to conver 320g/kW.h into L/hr for a diesel generator 13kVa , at 50Hz with an output voltage of 230V.

If we assume output is actually 13 kVA and power factor is 1 (worst case), it is 13 kW x 320 g/kW·h = 4.16 kg/h As density of diesel fuel is around 0.85 kg/L, that is 4.9 L/h at max power. If at less than max output power, consumption will be somewhat less.

[Unregistered]

JohnS, in your last post you divided 4.16 by 0.85 to get 4.9. Shouldn't you have multiplied 4.16 by 0.85 to get 3.54............or am I mixed up?

[JohnS]

JohnS, in your last post you divided 4.16 by 0.85 to get 4.9. Shouldn't you have multiplied 4.16 by 0.85 to get 3.54............or am I mixed up?

4.16 kg/h x 1 L/0.85 kg = 4.9 L/h

I recommend always leaving the units attached to the numbers and working the units cancellation; it is always clear whether to multiply or divide. You can still make errors by using wrong conversion factors, but it is much easier to check all the inputs to the calculation.

[Unregistered]

Right you are. Thanks for the clarification.

[Unregistered]

If a 500 kW diesel generator has a fuel consumption of 208 g/kWh at full load. How much it will be at 50% and 25% load? Thanks

[Unregistered]

may i know in the previous calculation whether you consider the efficiency already? i looks the genset has a round 50% efficiency.

[Unregistered]

how to compute kwh/liter?

[JohnS]

how to compute kwh/liter?

Measure the engine's power output (kilowatts) and fuel flow (liters per hour). Divide.

It varies with the heat content of the fuel and the efficiency of the engine. For a particular engine and fuel, it varies considerably with torque and rpm (the plot is called an engine map, and shows brake specific fuel consumption contours vs torque and rpm).

[PLOPPO]

There are 453.6 grams per pound.

230 g/kw hr = ( 230/453.6 ) lb/kw hr ~= 0.507 lbm/kw-hr

There are approximately 7.4 pounds / gallon for #2 D diesel fuel

0.507 lbm/kw-hr / 7.4 lbm / gal ~= 0.069 gal / kw-hr

If 60 kw, then hourly fuel oil usage ~= 0.069 x 60 kw ( kw drops out ) = 4.11 gal/hr

The reciprocal of "gal/kw-hr" i.e. "kw-hr/ gal" is a more used term of electric generator efficiency using diesel engines.

In this case 1 / 0.069 ~= 14.5 kw-hr / gal. a very competitive level.

[Nahidh]

each KWh will consume 0.31 liters for small machines ( under 50 KVA ) , 0.26 to 0.28 for mid machines under 250 KVA , and 0.252 litres for large machines , for DS#2 fuel

[Unregistered]

If a 2650 kW Main Engine has a fuel consumption of 210.2 g/kWh at full load. How much it will be at t/h ? Thanks

[JohnS]

If a 2650 kW Main Engine has a fuel consumption of 210.2 g/kWh at full load. How much it will be at t/h ? Thanks

210.2 g/kWh x 2650 kW x 1 t/10^6 g = 0.557 t/h

[Unregistered]

210.2 g/kWh x 2650 kW x 1 t/10^6 g = 0.557 t/h
Thank you....