Calculating the Capacity of Bulk Fuel Tank

Salakomuniru, I suspect you will soon be receiving requests for more information.

There is no way that anyone can give you any figures without knowing what type (brand, model, size, rpm, horsepower, etc.) of engine you have.

However, if you know how much fuel your engine consumes per hour, you can easily calculate the required capacity yourself.

Vulcan is right,

After calculating the required capacity a safety factor should be added for providing for:

Adjustment going wrong, Fuel delivery problems -fuel workers strike or weather.

Workers using more power than anticipated - Heaters in the winter. etc

etc.

The cost of additional capacity will be negligible compared to the cost of loosing production.

I estimate just under 40 m³ based on following.

Depends on precise spec requirements, but assuming it's at design output the whole time.

1250 kVA at 0.8 PF = 1 MW. Efficiency, fuel - elec power 30% (should be a safe figure) → 3.3 MW diesel = 3.3 MJ/s = 1440000 MJ in 120 hour. Calorific value of diesel 44 MJ/kg → 32730 kg diesel. Density 850 kg/m³ → 38.5 m³.

Cheers.....Codey

Speak to your Generator Vendor - Dohh!!

Considering specific fuel consumption at full load, the sizes of storage tanks, the deliveries by the trailer load of approx 7,000 USG, the need to always have enough fuel on hand to meet the 120 hour demand at full load, periodic incidental testing and operation at less than full load and at less than 120 hour duration, and that after a 120 hour run you can get at least one trailer load of fuel before your next 120 hour run, and a margin of safety... Get a 30,000 US gallon storage tank.

Ask your engine manafacturer for fuel consumption at Deffrient loads(25%,50%,75%and 100% Loads) based on the figs make provisions 48 hours operation based on type of applications Standby/peakshaving or prime/Continues operations.Please note fuel consumption will be expressed in Gm/Bhp/Hour you have to convert this fig to ltrs using D=M/V

crm

Hello Sala,

As has been suggested already You only need to kow the rate of fuel consumption of the generating set and multiply it by the time of use (120hrs) as stated by you to get the volume of bulk tank needed; as follows:

Vol. of bulk tank=(rate of consumtion of Generator) X (time of operation required)

= X 120hrs

= in cubic meters

All the best.

Bernard

I found 2 website that were useful in purchasing a generator and tank.

http://www.whatgenerator.com

http://www.generatorguru.com

Hope these are of help.

Fuel consumption at maximum power is 0.278 lbs per hp per hour (Brake Specific Fuel Consumption). Fuel consumption at maximum economy is 0.260 lbs/hp/hour. At maximum economy the engine exceeds 50% thermal efficiency. That is, more than 50% of the energy in the fuel in converted to motion.

For comparison, most automotive and small aircraft engines have BSFC figures in the 0.40-0.60 lbs/hp/hr range and 25-30% thermal efficiency range.

I hope this helps.

Hello jrpeck - I make 0.26 lb/(hp.hr) over 51% efficient, which seems quite optimistic. Is this a test-bed figure or real-life, i.e. net of power for cooling fan, water pump, oil pump, battery charging alternator etc?

Still need to take account of generator efficiency - low 90s % for this size?

Cheers.....Codey

Talk to the manufacturer of the engine. They can tell you what estimated fuel consumption is under load. Use those figures, add 25% and design a tank to meet this requirement.

It's really not rocket science.

As I recall a 1000 hp engine burns about 3 gallons per minute or 180 gallons per hour. For 120 hours, this computes to about 21,600 gallons. Confirm fuel consumption with your generator supplier, and do the math. Make sure your units are correct. Post the result that you get, and we will be happy to check your calculations.

Hello Salakomuniru - assuming you take advice of various contributors and contact generator supplier, will you post the results? I'm curious.

Incidentally, I would expect your client to give a proper design basis for the tank and the 120 hours to be actual running time required, i.e. he has allowed for length of power outage, loads, minimum delivery volume, safety margin etc.

Cheers......Codey

Hello Codemaster,

I thank all contributors to my post. I will contact the generator manufacturer and will post the results as requested

Have a nice day

Hello Salakomuniru

You were going to post results from talk with manufacturer. Any news yet?

Codey

Hello Salakomuniru

We're still waiting! There was quite a range of suggested volumes and I'd like to know how close anybody got. That way we can all learn something.

Codey

What you need to calculate is for a auxiliary tank. Which will provide sufficient fuel if some one forgets to call in the fuel company for refill of main tank. The more remote the location the longer it will take.

Main tank can be any size. I would size it to being filled on a weekly or bi-monthly schedule.

The manufacture of the generator or the motor should be able to supply you fuel consumption at full load. Use that as your rate of consumption.

Thanks ozzb your comments noted

Just did the same for a hospital.

I don't think we had to assume that the gen-set was fully loaded. I think the requirement was 80%.

We did however have to allow for the fact that to avoid overflows when filling and expansion concerns the tank could be filled at most 90%.

Finally as we could not draw out the bit of fuel in the bottom of the tank, that could not be used. The fuel oil is drawn from the top of the tank with the pickup close to but not all the way to the bottom of the tank.

Fuel usage rates for the generator are available from the manufacturer. Some reasonable estimates were given on this page. It should be something on the order of 270 liters/hr for full load.

Not to sound like a smartass or anything, but I think you need to spend some time in the USA and learn. ANY project Engineer that couldn't figure that out, wouldn't be one for long.

i suggest that go through ISO Standards on this subject i you need any assistence i shall be glad to help

Most Gensets use about 210 g per KW hour therefore your capacity required

= 1250*.8*.210/.83*120 =30361 Liters diesel.

AT FUEL LOAD A 1000 KW GENSET BURNS 70.9 GPH SO 71 X 120 NOW YOU KNOW