20Kva Generator

[stuart m]

Hello all,
Im chasing any helpfull info to run my water cooled 20Kva Kabota/Denyo Generator on WVO (two tank system ,heating oil via heat exchanger or electric element etc etc.The generator is my only power source and runs from 0700-2230 every day.

Stuart.

[craigcurtin]

Re: 20Kva Generator

Stuart, Should not be an issue - although you have not quoted an actual model number, the newer ones are direct injection.

Definitely two tanks - start on Diesel/BIO, until warm, then switch over to straight oil, 10 minutes prior to shutdown switch back to diesel to flush the system.

A Single pollak 6 way valve will do this for you - as you will be able to harness the waste heat from the water coolant you could actually also look at using High Melting Point fats in a 3rd tank (or even lard) - both of these are easier to find than WVO (most vegoil guys give them away - and even a lot of BIO guys give away lard.

If you are running a 20kva unit i take it you are running a workshop or something so you may want to look at automating the whole thing (assuming you are doing an automatic startup on the generator etc) - if you are handy you could look at something like a Picaxe processor to build a system or buy one of the automation units from the States.

Craig

[Captain Echidna]

Re: 20Kva Generator

I was thinking the same things with three tanks, using lard etc, but if changing over is not a hassle, going for ball valves instead of pollack valves.

[Tony From West Oz]

Re: 20Kva Generator

Stuart,
I agree with both of the previous posters. The Pollak valve is barely suitable for vehicle use. It is only rated to 80°C and it is not uncommon for the temperatures under the bonnet to exceed 100°C.
I recommend that you contact Omarsales and purchase a pair of their solenoid changeover valves, which I believe will give excellent performance for your application. These are designed for use with vegetable oil fuels and are rated for continuous operation.

Is your 20KVA unit water or air cooled?

you may need to use an oil/fuel heat exchanger if using oils which are more viscous, or an oil/water heat exchanger if needing to melt oil in a remote fuel tank. A pump for the water and insulated lines may assist in melting the oils more rapidly.

Regards,
Tony

[Johnnojack]

Re: 20Kva Generator

Why solenoid valves? This is a stationary engine and would have all its fuel lines exposed. So easy to have ball valves. Just switch the diesel off and the WVO on. When stopping do the reverse (5 or 10minutes before stopping). You can see what you are doing and it is going to last a lifetime. What advantage is a complicated system unless you want to do the switching remotely from another building. Maybe you do want to do that.

[Tony From West Oz]

Re: 20Kva Generator

Or even automate it completely, using a microprocessor as suggested. . . . .

[Geoffwin]

Re: 20Kva Generator

Also use the heat to hot filter the fat / oil / lard on a separate circuit. Since it runs daily this would probably be always warm as well.

I agree a couple of ball valves is probably the easiest Unless you wish to automate.

Geoff

[craigcurtin]

Re: 20Kva Generator

Stuart,

As this is your only power source i would also look at some form of stored heat to keep the oil/lard upto temperature and also make the starting easier on the generator (keep the head warm).

Some form of hot water cyclinder that was tied into the coolant loop on the unit with a small 12v circulating pump

Craig

[Johnnojack]

Re: 20Kva Generator

To move the topic a little. How come you do not have a Stand alone Solar power system (SAPS) with batteries etc for power? Maybe that is the long term plan? You do know that if you can't get State power where you are, that you can get a 50% rebate from the federal Govt to put a SAPS in. You could still use your WVO generator as a backup.

[craigcurtin]

Re: 20Kva Generator

i am guessing here - but if he is running a 20kva unit at approx 80% load for optimum diesel perfomance then that is a 16Kva load.

I could not begin to do the numbers in my head for the maths on the cost of a battery bank to povide that much power over a 15 hour period each - assuming a drawdown on the batterys of only 50% for longer term longevitiy.

As to the solar panels required that would also be enormouse - based on 200 watt panels at $1500 each - you would need 80 panel (assuming 100% efficiency (and we know they are not)

Craig