Micro CoGen.

Quote from: SteveU. on June 24, 2013, 07:26:43 PM
Best of all page #44, illistrations #77 & #78 chart out the intake/exhaust opening and closing timings with the valve opening overlaps.

It's not totally necessary to use different valve timing events for intake and exhaust on a normally aspirated diesel.  A turbocharged engine can take advantage of increased overlap time and duration on the intake side.  But a normally aspirated engine, especially these little ones with the air intake design they use to dampen the intake noise, is not going to benefit much from it.
--
Chris

Quote from: SteveU. on June 23, 2013, 06:50:38 PM
Thanks for the tip off on the Hatz engine weaknesses ChrisO

I've never had real good luck with the Hatz engines.  I have had two of them on Scot pumps and neither one lasted even half as long as my Honda gas engines on the same pump.  After about 1,500 hours the link on the injection pump gets sloppy due to cam wear and they lose injection pressure due to lost stroke on the pump.  Then they won't start and got no power and smoke real bad.

Yes, there's a lot of similarities between the Robin and Yanmar L-series engines.  The Robin engines have been around for a long time - when I was a kid we had a twin-cylinder Wisconsin-Robin diesel on our hay baler.  I think it was 27 hp - and that baler was built in the late 50's.
--
Chris

Quote from: Dualfuel on June 22, 2013, 06:28:49 PM
Is that Robin engine a Yanmar clone or an actual yanmar? I have two 4kw yanmars...I really love them...

No, it's a Robin engine.  It is built by Fuji Heavy Industries in Tokyo, Japan.  They were originally called Wisconsin-Robin, with the engines built by Fuji Heavy Industries and marketed by Wisconsin Engines (Wisconsin Motors) in Waukesha, Wisconsin.  There were thousands of them built for the military for small portable 3 kw diesel gensets - the engine was originally called the Wisconsin-Robin WRD1-270.  They gained such a reputation for ruggedness in the military services that used ones sell for more than a new Honda.  They are still in service in the US Army and US Marines and you can occasionally find them used on government liquidation sales.

Wisconsin Motors quit handling the Robin engine and then they were marketed under the name of just Robin, but mostly overseas.  They are quite common in Europe and Asia, but not in the US.

Then Subaru bought the rights to sell them and the company is now called Subaru-Robin.  The DY27 that's on my generator is still built by Fuji Heavy Industries in Japan and sold all over the world today, except not sold in the US or Canada since 2004 because it doesn't meet EPA.

Edit:
I should clarify this:
Then Subaru bought the rights to sell them and the company is now called Subaru-Robin.

Subaru is actually the automobile manufacturing division of Fuji Heavy Industries.  Subaru Power (called Robin America in the US) is the fourth largest manufacturer of industrial engines on earth:
http://robinamerica.com/
--
Chris

This is what I'm using the little diesel for:

We got no wind power with only a 6 mph breeze. We got 6.0 kW installed capacity solar, and the solar is only running at about 20% of its rated output due to heavy overcast, thunderstorms overnight. I got a bunch of work to do in the shop after lunch that's going to take about 30 kWh in 5 hours. Plus we got water to heat and other stuff to run. Plus I got walleye fishin' to do tonight. You can either wait for the weather to get your work done, or start the little generator and say to heck with the weather.

The little diesel will supply roughly 1/3 of that power for five hours this afternoon, and the inverter will supply the rest, assisting it for peak loads.

This is all it takes to bring the little diesel online for prime power for a few hours today, and save on the batteries:


--
Chris

Quote from: Dualfuel on June 21, 2013, 08:03:05 AM
and a Magnum MS 4448. That generator support feature would be very useful for the applications I had in mind...

The Magnum MS4448 doesn't have generator support in it.  But Magnum has just released their new inverter that does have it - the MSH4024RE
http://www.magnumenergy.com/products/MSH-REseries.htm

--
Chris

Quote from: Tom on June 20, 2013, 03:17:27 PM
I also have an SW2512 from which I was familiar the gen support, but never used it.

Indeed, it's a very handy thing.  It's how we run our big stuff here on off-grid power without spending an arm and leg on fuel and inverter equipment/batteries to do it.  Using a small AC generator for peak load with the inverter helping it out is much more efficient than digging into your batteries to run those big loads, then having to charge batteries with an inverter/charger.  The peak load support from the generator takes the load off the system so the RE sources can keep up with charging batteries, and minimize the use of the generator for charging.

I'm amazing how many people don't know what it is, or what it does.  I made a video once with our old system, demonstrating it:


--
Chris

Quote from: SteveU. on June 20, 2013, 01:48:38 PM
Hey ChrisO
Thanks for putting up the picture of your Suburu/Robin RDG3300H gen-set.
http://robinamerica.com/
http://suburupower.com/
That led to the Hatz 1B30 aircooled diesel engine that they list as using.

Steve, the Robin DY27 was last sold in the US in 2004.  It is still manufactured in Japan and sold to overseas markets today where EPA regulations don't apply.  I've seen a lot of problems with the Hatz diesels - especially their injection pumps.

The Robin was always famous for being virtually impossible to break back when the company was called Wisconsin-Robin even.  There was thousands of them built for the military back in the day (it was called the Wisconsin-Robin WRD1-270 diesel back then).  I remember a construction company that had a DY27 on a 2" pump and they dropped it from a crane and bent the governor linkage on it.  They hooked it up and ran it anyway with the fuel rack stuck at full fuel.  Then decided it must have a problem because fire and black smoke was coming out of the exhaust and the muffler was orange.  So they took it to the Wisconsin-Robin dealer and they fixed it, and it was still running fine several years later when the impeller in the pump finally wore out.
--
Chris

Quote from: Tom on June 20, 2013, 12:04:20 PM
Oh how I wish the Outback inverters we have had a functional generator support system. That would solve almost all of the issues we have by being limited to 3KW while charging. But alas all we have is the menu item on the control console and no hope of future support from Outback.

Tom, the Outback Radian inverter does have generator support advertised.  We strongly considered one but Outback and the dealer were not able to answer my questions as to how it functions compared to the SW/SW+/XW-series inverters, which have had it for almost 20 years thru the various models.  We were sent by the dealer to see a running Radian system in central Wisconsin that was supposed to have generator support set up.  When we got there we found out that they didn't really know what generator support was.  They thought it was the Generac 12 kW Guardian that they had modified for two-wire auto start when the batteries got low.

We were a little disappointed in that.  And even though we would've liked the additional capacity of the Radian inverter we decided to buy the XW because it's a proven system.  And Schneider's tech support was absolutely superb in helping us get it set up properly so it works with our small 3.6 kVA Honda generator.  I have load start set at 47 amps and it brings the generator online if the load exceeds that for five minutes, warms it up for one minute then puts it to work at its full rated 3.6 kVA prime capacity while the inverter carries the balance of the load.  When the total load drops below 47 amps it waits for one minute and if the load remains below 47 amps it disconnects the generator, cools it down for 90 seconds, then shuts it off.

It works, very very well in the XW, just like it always did in the SW/SW Plus.  Pretty much totally seamless.  And that's all I wanted to know about how the Radian does it.  But Outback just told me, "Oh, you probably won't need it anyway."  So I don't think they yet understand what it's about - which is conserving energy from the batteries during high draw times to prevent discharging your bank at the 2 hr rate.  And being able to do it with a smaller generator.

I have since talked to a couple people that have more experience with the Radian and it turns out that gen support in it is not true gen support like it's always been in the SW/SW+/XW.  They evidently adapted the grid support function from the GVFX-series into it, they still do not build an integrated generator controller, and the Radian appears to be targeted more towards larger grid-tie systems with battery and generator backup rather than true off-grid.  Which in fact, I don't know anybody that lives off-grid that can afford the batteries to run a big inverter like that just on battery power at full rated load for more than about 10-15 minutes.

The Radian is very new and yet unproven.  But perhaps they will enhance it with time.  It was a very nice-looking inverter.  Although I can't say that they made any significant improvements in the menu layouts in the Mate3 vs what the old Mate had.  The XW's menus are much easier to understand and find what you want to set or adjust.

So we've been overall happy with the XW6048.  We don't use the charger in it much - maybe 8 or 10 times since we've bought it.  But when it's charging with the generator, if the load exceeds the generator's capability it seamlessly switches to gen support and helps the gen out.  So the power from it VERY stable.  We don't even get a flicker in a CFL light bulb when I strike an arc with my Lincoln 225 amp welder in the shop.  It will handle 7.2 kVA overload for 30 minutes pretty easily before it starts to complain about overheat or AC overload.  And it will handle larger overloads than 7.2 kVA for shorter times, up to about 12 kVA for 15-20 seconds.  So it's got considerably more overload capacity than the SW Plus 5548 had.
--
Chris

Quote from: mobile_bob on June 20, 2013, 10:01:27 AM
Nice clean installation there Chris!

very well done

Thanks Bob - we had dual SW Plus 4024's on the wall there a couple years ago.  Then went to a single SW Plus 5548 to get away from leg balancing problems with the stacked inverters.  But the 5548 didn't have quite enough "snoose" under the hood so we put in the XW.
--
Chris

Quite a bit of the power consumed here is in my machine shop, which is powered off our XW6048 also.  If I'm doing a lot of welding and/or lathe and mill work I can pretty easily burn off 20 kWh in a day in the shop.  My wife won't allow a propane line coming into the house.  So we have all electric stuff there too, including water heating.  But surprisingly, things like her induction range with a convection oven are fairly easy to run on off-grid power.  If the inverter overloads it auto-starts our Honda generator and uses Gen Support to meet the load until it goes away, then shuts the gen off.  Those really heavy loads are usually very short in duration so the amount of fuel used for peak load support is almost negligible.

The real problem is my shop.  The little Robin running on the inverter's AC1 input programmed for Grid Support while I'm doing a lot of high power stuff in the shop will make a big difference.  And I can live with the fuel burned because it's minor compared to what I'm doing in the shop.

On really good days with nice incoming RE power we can 95% of the time power everything with the XW straight up.  If my wife is doing some high power stuff in the house, then I have always pre-started the Honda to have it online for Gen Support before I do anything in the shop like welding.  But I think the little Robin will take enough "edge" off the loads to keep from digging into the batteries too deep, and be more efficient than running the larger Honda.

This is the new powerhouse I built with both generators in it:



This is our utility and battery room:


--
Chris

We work our batteries pretty hard.  They are most times never above 80% SOC for 7-10 days at a time.
--
Chris

Quote from: Dualfuel on June 13, 2013, 10:45:29 PM
I read something on this thread that startled me...the idea of wanting to run a generator instead of using battery power.

We've been living off-grid here since June 2002.  What's startling is the cost of batteries.  They're the most expensive component of an off-grid power system.  We got $9000 in our Surrettes and they're good for about 1700 cycles.  That means if you cycle them every day the cost per year in batteries alone is about $1,800, or about $150/month.  Using the battery power is fine as long as they're charged by RE sources of power.  But when the weather don't cooperate and you have to charge a sacked bank with a generator you're throwing good money after bad.

We use 30+ kWh/day here and our bank can store 28 kWh down to 50% SOC.  During the days in winter when we only get 3 kWh in a day from solar and wind, I can buy a lot of damn diesel fuel for a little prime power diesel generator that's properly matched to normal loads compared to what it costs to cycle those batteries and then burn the fuel anyway to recharge them.  Using the small diesel prime power generator lets the batteries float during those times instead of using up cycles, and basically I can run that Robin diesel 24 hours a day, 10 days out of a month for less money than it costs us long term to cycle the batteries every day for the month.

Off-grid living is expensive - WAAY more expensive than even buying power off the grid for 30 cents/kWh.  Many people have a misconception about that because they think we don't have a utility bill.  Well, I got news for ya' buddy - the utility bill is a lot cheaper than what it costs us to keep the lights on.  But we also like where we live and 11 years ago there was no way in hell I was going to pay the utility company $168,000 to run powerlines to our place.

So this is all about reducing the expense in batteries over the long term.
--
Chris

I got my new powerhouse built and the Robin installed in it.  Although not done insulating it yet and our Honda EM4000SX goes in there too.  Plus have to bury electrical service and control wires for gen auto-start to the building yet.  Just using a 200 foot 10 AWG generator cord at present.

Since this generator is for prime power during bad RE times, or heavy continuous load times, I decided to make a 24 hour run with it to see how it does.  I ran it from 6:00 PM yesterday to 6:00 PM today.  I shut down my wind turbines but left the solar arrays operating, and disabled the charger in the XW6048.  So all the generator powered was our normal loads for the 24 hours.  Which is easy to measure because I got an old utility kWh meter on the XW that keeps track of our daily power consumption.  I set the load on the generator set to 3.05 kVA (13 amps) in the XW's Gen Support menu.

We used 36 kWh during the 24 hours and the Robin burned 5.3 gallons of fuel - the fuel measured with the meter on the 125 gallon fuel tank in the back of my service truck.  The tank on it only holds about 3.5 gallons so I had to refuel it this morning after breakfast.  The numbers are a little skewed because several times the loads exceeded what the Robin can put out for power so the XW assisted it from RE power using Gen Support.  But again, this is NOT a BSFC test!  It's a 24 hour run with the generator on prime power duty to see what it's going to do when we need to run it in the winter for several days at a time.

This is the powerhouse:



This is the generator inside it, running



This is the load on it at the time I took the photos:



This is a short video of it operating inside the powerhouse on its 24 hour test run

Quote from: Ronmar on June 09, 2013, 01:29:31 PM
Chris, if your original post wasn't about fuel consumption, then what was it about?

It was about using this little generator for prime power when we want to run our AC unit in the summer, or get bad RE production in winter.  I was curious to see what it burns in an hour to decide if it's worth it to install an external fuel tank when I built my new powerhouse where it's installed now.  I burn over 60,000 gallons of diesel fuel in my equipment and semis in a year's time.  So whether this thing burns 2cc/hr or 2 gallons/hr, it don't matter.  The one and only thing I wanted to know about fuel consumption is how many times I have to refuel it per day if it runs for several days at a time.  Like I said before, how the hell that got misconstrued into BSFC from a post on another forum is beyond my wildest imagination.
--
Chris

Quote from: mobile_bob on June 09, 2013, 09:55:54 AM
i think that is a very constructive position/hypothesis, one you would find much agreement on here i suspect.

The thing is, nobody that I know does this, though.  Short of a few that run co-gen units.  Why?  I think it's all mind-set.  Off-grid folks tend to have the belief that running a generator is "bad".  You're supposed to use wind, solar, hydro, etc., and running a generator is like a "sin".  But it's not, IMHO.  Most off-grid folks make the mistake of buying a generator that's way too big and then they can't afford to run it because it's maybe 50% larger than needed for charging batteries, and WAY bigger than needed for normal loads.

So I intend to pursue my theory that a small generator can be used more efficiently by passing power from it direct to loads rather that using the batteries for bad RE production times, and then having to "catch up" by using a generator to recharge them.

Quote
as for heavy oils, bunker or coal slurries

Heavy oils are very good.  Coal slurry is terrible.  It takes roughly 2 BTU's of input using coal slurry for every 1 BTU of input using heavy oil to get the same power output.  We certified some K engines back in the 80's for coal slurry for mining operations.  But the market was not big enough to justify the engineering cost and it eventually became a dead issue.  Now, with all the talk of "alternative fuels" it's being revisited as the best thing since sliced bread.  But the engineers of today must've forgotten the lessons we learned 30 years ago.

Quote
anyway we use pump diesel fuels for the most part and always for testing around here, and engine's of similar design, size and speed will produce bsfc numbers very close to one another, generally all within 5% from worst to best.

Basically, that's because pump fuels don't vary by more than 5% on energy content, usually.  BSFC numbers are established by manufacturers normally based on straight #2 fuel with a cetane number of 40, in whatever version the EPA considers acceptable at the time.  In real life, premium fuels with a cetane number of 48 or better will yield better thermal performance than the baseline test fuels, usually by 3-5%.

You stated earlier:
we certainly cannot conclude the engine/generator is 30% efficient!

I didn't say this.  I said the little engine is roughly 30% thermally efficient, based on some quick calcs in my head.  Not the engine/generator combination.  Efficiency is given by 1/(BSFC × 0.0119531) using a baseline #2 fuel with 0.0119531 kWh/g energy content.  This even agrees with the manufacturer's publish BSFC numbers on the little Robin, assuming the engine is running at about 80% rated power with the gen head at full rated output, so the real shaft power is only going to be around 4.5 hp @ 1,100 ft elevation without manifold pressure compensation via a turbocharger.

I was happy with this, as most gasoline engines in the same size class are going to be in the 20% thermally efficient range.  That just meant to me that I had made a good choice for my off-grid prime power project.

You can get more efficient engines.  But few of those engine/generator combinations will produce stable enough power for a XW inverter's AC1 input.  This little Robin does.  But it took some tweaking to get the torque rise up and prevent loss of freq during overload so the inverter wouldn't disqualify it.  And the injector opening pressure was too low, as it was misfiring at high idle no-load.  So I took that apart and shimmed it for 195 kg/cm² opening pressure, and then it ran perfect.  It was deliberately set to the low side of the spec at the factory to start the injection event sooner - main due to a design flaw in the timing advance not providing enough advance for a high-speed engine.  But with a little wear on the nozzle tip after 500 hours the performance of the engine degrades due to a poor spray pattern, without shimming it up.

So I think it will work for my intended purpose, and be efficient enough to achieve my intended goal.
--
Chris

Bob, and all - this gets to the meat of the topic of the thread I started on Fieldlines.  I has nothing to do with BSFC, etc..  All you can do is very rough figuring without a real dynamometer on any of this.  And at best, that's what it is - rough.  I do not wish to get into an argument over the details here, any more than I did there.

But I have to inform you, Bob, that changing fuels varies a diesel's performance by even more than 10%, depending on what you use.  Mobile engines don't achieve anywhere near the efficiencies of stationary and marine engines on heavy fuel oils, even though identical combustion chamber designs can be used in both.  And some (like the Cummins QSK) are designed for both fuels.  Operating a diesel on #4 vs 70% 20 micron coal slurry yields a difference in thermal performance approaching 50% with the identical combustion chamber.

The entire topic was about believing that the traditional method of applying off-grid standby power is flawed, and it is flawed due to manufacturers of inverters putting battery chargers in them so AC generators can be used for charging batteries.  Due to that fact, it has become the defacto-standard way of recovering during periods of poor RE production.  I believe using a small genset that is properly sized to the normal loads, and using it to power those loads directly, is more efficient that digging into the bank and then recharging it with an AC generator and inverter/charger, or using a DC charger.

But that topic got lost in the heat of the moment, and this is probably not the forum to present such a thing anymore than Fieldlines is not the proper forum to get into a big argument over BSFC.
--
Chris