This is a simple generator I design for my side work and emergency power.
I got a 6hp diesel engine on Ebay for $550.00 with shipping.
I had a 10kw Harbor Freight generator head, it cost $299.00+tax
For a total of $866.94 I have a generator that runs at 2800 rpms and the generator head at 3600rpm or a ratio of 1:1.25
This unit runs for 8 hours at 75% load with a 3.5l or .92gal fuel tank.
6hp diesel engine:
http://www.ebay.com/itm/NEW-6HP-SMALL-DIESEL-ENGINE-WITH-ELECTRIC-START-6-HP-/180700361816?pt=LH_DefaultDomain_0&hash=item2a1294b458 (http://www.ebay.com/itm/NEW-6HP-SMALL-DIESEL-ENGINE-WITH-ELECTRIC-START-6-HP-/180700361816?pt=LH_DefaultDomain_0&hash=item2a1294b458)
10kw generator head:
http://www.harborfreight.com/10000-watts-max-7200-watts-rated-belt-driven-generator-head-45416.html (http://www.harborfreight.com/10000-watts-max-7200-watts-rated-belt-driven-generator-head-45416.html)
My unit:
https://www.youtube.com/watch?v=yLaHcYUbEBc (https://www.youtube.com/watch?v=yLaHcYUbEBc)
I always enjoy your projects. If only Gary would decide to come back on the air!
The back of my napkin: 0.92 gallons is 125MJ, at 8 hours run = 4.33kW equivalent fuel input = 5.85 hp equivalent fuel input. If you are getting 75% of 6 hp output then you are breaking efficiency records for inexpensive normally aspirated diesel engines. So you probably want to double check your numbers.
If you got that 8 hour run time on 0.92 gallons with a 1.5kW or greater electrical load then you would be getting 32% or better LHV utilization from the fuel which would be very good. 10kW - 20kW commercial diesel gensets tend to top out around 40% LHV utilization.
I will do a run test and check my calculation again, thanks.
I will do a video to show true output verse input of diesel fuel.
Sounds great.
I would like to add that diesel has about 130,000-135,000 btu's, gasoline is between 120,000 to 125,00 btu's
125,000 btu's x 40%=50,000 btu's
50,000btu / 3.41=14,662 total watts or 14.662kw
14.7662kw/8hr=1.83kw per hour
This is at 50% load data.
125,000 btu's x 75%=93750 btu's
93750btu / 3.41= 27,892total watts or 27.892kw
27.892kw/8hr=3.436kw per hour
Quote125,000 btu's x 40%=50,000 btu's
50,000btu / 3.41=14,662 total watts or 14.662kw
14.7662kw/8hr=1.83kw per hour
This is at 50% load data.
The units are not quite right:
1 BTU = 1055J
1 BTU/h = 1055J/3600s = 1/3.41 W
125kBTU * 40% = 50kBTU
50kBTU/8 hours = 6.25kBTU/h * 1/3.41W/BTU/h = 1.83kW
1.83kW * 8h is 1.83E3J/s * 8h * 3600s/h * 1 BTU/1055 J = 50kBTU = 40% of the energy in 125kBTU, and
3.44kW * 8h is 3.44E3J/s * 8h * 3600s/h * 1 BTU/1055 J = 94kBTU = 75% of the energy in 125kBTU.
I went straight to J. If we work it in BTUs first, we get:
118kBTU/tank * 1 tank/8h = 14.75kBTU/h * 1/3.41W/BTU/h = 4.32kW input power equivalent.
Efficiency = Continuous output power / 4.32kW