90cummins
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MEP 952b fuel consumption test.
We had a scheduled power outage so the electric utility could upgrade the power lines so I thought it would be a good excuse for me to perform another more accurate fuel consumption test.
In the past when performing a fuel consumption test I measured the quanty of fuel consumed using a 5 quart container which while not very accurate did give me data that I used to make calculations and adjustments pertaining to my equipment.
On my last test I used a spring scale so I could hang my fuel supply and calculate consumption by weight. This removed much of the human error involved when measuring the amount of fuel consumed however I was not sure how accurate it was. This prompted me to search for scales and I found a very accurate 90lb electronic postal scale that was reasonably priced so I purchased one on Ebay.
The scale is rated at 90lbs and displays in pounds/ounces, ounces and kilograms down to 1 gram.
This scale will allow me to precisely measure and calculate fuel consumption at various loads and allow me to determine the most efficient engine speed and timing for maximum efficiency.
The heart of my backup system is a Xantrex XW4024 4kw pure sine inverter with a surge capability of 8kw. My battery bank has a capacity of 570ah's, and should be able to operate my home thru a winter night supporting heat and all essentials including my water pump.
Googling the weight of 1 gallon of #2 diesel resulted in answers from 6.7 to 8.2 lbs per gallon. I even stopped into my local oil dealer and the said they use 7.7 lbs/gallon for shipping.
During my days in transmission engineering (Bradley Fighting Vehicle) we operated large diesel test cells ranging in size from 500 to 1200 hp and used 7.2 lbs per gallon to calculate fuel connsumption using off road diesel so 7.2 lbs is the number used in my calculations.
My test.
The MEP-952b has a Farymann 43F single cylinder direct injected diesel rated 15hp at 3000rpm and has two heaters in the intake and oil sump for operation in subzero environments. The engine directly drives a 28 volt Niehoff 6 phase alternator rated at 280amps. It has no fuel or batterys so it needs external sources for each. It has an electric fuel pump and an attached 30' hose for connection to a fuel source and power is via a NATO 24v plug.
Maxium torque is 27 lbft at 2000rpm with a bore of 3.75 inches and a stroke of 3.94" for a displacement of 738cc. The rated output is 5kw 28 volts @180 amps.
Previous testing at 3000 rpm resulted in approx 2.5 hours per gallon. To reduce fuel consumptiuon I tried to slow the engine by backing off on the throttle using the lever however due to the govenor design the engine would not respond to changes in load and would slowly stall out.
After much thought I removed 2 of the 3 govenor springs leaving in place only the high speed spring. The results were very good with excellent load response and speed control. No load engine speed is now 2428 and at full load is 2299rpm with an AC load of 4.29kw. The DC load was 202amps @ 25.4volts which was a load of 5130.8 watts.
My test procedure;
The APU is connected to my battery bank using an Anderson 350amp 2 pole connector and the fuel line is inserted into the fuel container which is on the scale. The APU is started and the load connected and allowed to stabilize engine speed was 2414 with an initial AC load of 0.46kw.
The time initial load and weight were recorded with the fuel & container weighing 577.6 ounces (36.1 lbs) or 16.366kg.
Laundry was being done so the washer was operating along with the well pump which cycled on & off along with other house hold items such as lights, fridgerator, 2 freezers & TV.
The unit was run for a total of 267 minutes (4 hours 27 minutes) = 4.45hrs. In that time it consumed 122.7ounces / 3.474Kgs of fuel which equals 7.669 lbs./7.2 = (1.065 gallons consumed) which works out to 1.723 lbs of fuel per hour.
No load speed at conclusion of the test was 2428 rpm.
Electrical conversion efficiency was 82.8%.
I'm very pleased with my results. At this consumption rate the APU can run 24/7 for 9+ days on 55 gallons of fuel.
My goal for the MEP-952b APU has been to attain a 4 hour per gallon run time while supporting my home under normal basic loads. To illustrate the significance of that I have a Honda EU2000i which is an amazing machine that will run 10 hours on 1 gallon of gasoline with a light load, however at the rated load of 1.5kw the run time is 4~5 hours so you can see it is not nearly as efficient as a properly sized and tuned diesel. The Honda is extremely reliable, handy, portable and quick to setup when needed but is not as efficient as you would think.
Looking forward to a full day of testing once I start my wood furnace to get real numbers.
90cummins
We had a scheduled power outage so the electric utility could upgrade the power lines so I thought it would be a good excuse for me to perform another more accurate fuel consumption test.
In the past when performing a fuel consumption test I measured the quanty of fuel consumed using a 5 quart container which while not very accurate did give me data that I used to make calculations and adjustments pertaining to my equipment.
On my last test I used a spring scale so I could hang my fuel supply and calculate consumption by weight. This removed much of the human error involved when measuring the amount of fuel consumed however I was not sure how accurate it was. This prompted me to search for scales and I found a very accurate 90lb electronic postal scale that was reasonably priced so I purchased one on Ebay.
The scale is rated at 90lbs and displays in pounds/ounces, ounces and kilograms down to 1 gram.
This scale will allow me to precisely measure and calculate fuel consumption at various loads and allow me to determine the most efficient engine speed and timing for maximum efficiency.
The heart of my backup system is a Xantrex XW4024 4kw pure sine inverter with a surge capability of 8kw. My battery bank has a capacity of 570ah's, and should be able to operate my home thru a winter night supporting heat and all essentials including my water pump.
Googling the weight of 1 gallon of #2 diesel resulted in answers from 6.7 to 8.2 lbs per gallon. I even stopped into my local oil dealer and the said they use 7.7 lbs/gallon for shipping.
During my days in transmission engineering (Bradley Fighting Vehicle) we operated large diesel test cells ranging in size from 500 to 1200 hp and used 7.2 lbs per gallon to calculate fuel connsumption using off road diesel so 7.2 lbs is the number used in my calculations.
My test.
The MEP-952b has a Farymann 43F single cylinder direct injected diesel rated 15hp at 3000rpm and has two heaters in the intake and oil sump for operation in subzero environments. The engine directly drives a 28 volt Niehoff 6 phase alternator rated at 280amps. It has no fuel or batterys so it needs external sources for each. It has an electric fuel pump and an attached 30' hose for connection to a fuel source and power is via a NATO 24v plug.
Maxium torque is 27 lbft at 2000rpm with a bore of 3.75 inches and a stroke of 3.94" for a displacement of 738cc. The rated output is 5kw 28 volts @180 amps.
Previous testing at 3000 rpm resulted in approx 2.5 hours per gallon. To reduce fuel consumptiuon I tried to slow the engine by backing off on the throttle using the lever however due to the govenor design the engine would not respond to changes in load and would slowly stall out.
After much thought I removed 2 of the 3 govenor springs leaving in place only the high speed spring. The results were very good with excellent load response and speed control. No load engine speed is now 2428 and at full load is 2299rpm with an AC load of 4.29kw. The DC load was 202amps @ 25.4volts which was a load of 5130.8 watts.
My test procedure;
The APU is connected to my battery bank using an Anderson 350amp 2 pole connector and the fuel line is inserted into the fuel container which is on the scale. The APU is started and the load connected and allowed to stabilize engine speed was 2414 with an initial AC load of 0.46kw.
The time initial load and weight were recorded with the fuel & container weighing 577.6 ounces (36.1 lbs) or 16.366kg.
Laundry was being done so the washer was operating along with the well pump which cycled on & off along with other house hold items such as lights, fridgerator, 2 freezers & TV.
The unit was run for a total of 267 minutes (4 hours 27 minutes) = 4.45hrs. In that time it consumed 122.7ounces / 3.474Kgs of fuel which equals 7.669 lbs./7.2 = (1.065 gallons consumed) which works out to 1.723 lbs of fuel per hour.
No load speed at conclusion of the test was 2428 rpm.
Electrical conversion efficiency was 82.8%.
I'm very pleased with my results. At this consumption rate the APU can run 24/7 for 9+ days on 55 gallons of fuel.
My goal for the MEP-952b APU has been to attain a 4 hour per gallon run time while supporting my home under normal basic loads. To illustrate the significance of that I have a Honda EU2000i which is an amazing machine that will run 10 hours on 1 gallon of gasoline with a light load, however at the rated load of 1.5kw the run time is 4~5 hours so you can see it is not nearly as efficient as a properly sized and tuned diesel. The Honda is extremely reliable, handy, portable and quick to setup when needed but is not as efficient as you would think.
Looking forward to a full day of testing once I start my wood furnace to get real numbers.
90cummins
