Hey Guys,
It was an interesting day yesterday indeed....(Ancient Chinese curse: May you live in interesting times.....)
Thump monster has started to ail..... I suspect that the exhaust is in need of a good decarboning, in fact I am certain of it! Monster ran reasonably well, but power was definitely down, it was only able to make 80% of the design power on the WMO while processing fuel.... I can tell by the exhaust sound that there are a few "restrictions" in the flow... Gone is the crisp sound at tail end, now a subtle thump.... Engine temps are up in the uncomfortably high areas and the output power is down. Putting this in perspective though, this is near enough 1600Hrs at last count, only major failure experienced was the head gasket which gave trouble from day one... No real decarboning has been done on the engine internals or head/exhaust, barring a minor bit of crown scraping to measure squish when the head gasket was replaced. Only other decarboning that I can remember doing on a semi regular basis has been the injector tip....
Of interest is the fact that at low head temperature, exhaust carbon buildup seemed to be able to be "flushed" with a heavy water injection run. With the higher head temps, the carbon buildup seems to be of harder and more dense nature - WI does not loosen it so easily. It may be co-incidental that the power drop off/performance loss occurred simultaneously with the use of WMO straight run, but I think not. I am under the impression that the exhaust was partially clogged pre starting the heavy WMO run, and the additional carbon/ash expelled in a higher concentration did a buildup trick way faster than expected.
Coinciding with this buildup is the fact that the "trials" are about to draw to an end. This engine has been used as a test bed, to see what I can throw at it, the mods required to keep it running, the reliability of the unit, the repair and attention required to keep it ticking over too....
Lets see what the day brings....
Keep it spinning...
Regds
Ed
PS - Latest update... I am now processing the final batch of fuel for what looks to be the year - It consists of 90% reclaimed diesel with drum washings from the WMO drums and processing plant making up the last 10% - This last 60 to 70 L will go into the last drum of de-watered sump-gunk for the last bit of fuel I will be running it on before I decarbon the plumbing system. Interestingly, today the power is slightly up on yesterday, if anything, I would have expected the warm weather (around 27C air temp) to have caused a bit of a power drop from yesterday... Goes to show, interesting times...
The performance/power has dropped now to below 4kw - 3.9kw to be precise - The original design spec was a nominal 4-5kw targeting 5kw if possible. This power output was largely attained, with the engine and genhead in "new" condition.... Peak instantaneous power of around 7.5kw is available from inertia store, but the sustained power output of 5kw is no longer possible - in rough figures, this would equate to around 10hp at the flywheel. Currently, it is running around the 8hp mark, or just under, giving an output of 3.9kw sustained max.
To recap - the engine has been down-rated from 1000rpm to 750rpm, at best it would be able to deliver(by estimate) around 2/3 to 3/4 of the design output of 12hp - ie 8 to 9Hp... so, in all, its still not doing too badly!
The unit is able to start and run on 100% WMO - Do I think its worth it? .... Possibly.... Yes.... if you have an unlimited supply of *free* fuel - this will cost you though, in time and effort - cleaning the fuel/finding the right injection timing to suit your batch of fuel(the timing required does change depending on the make up of the fuel...)/Setting up a water injection system to hold carbon deposits at bay/setting up an injector pre-heater for more efficient burn... and above all, getting the most out of the fuel you can by reclaiming exhaust heat/radiator heat as well....
Is it a lot of work... Yes.... Is it ongoing work.... Yes .... Is it a system that you can leave to the missus to run while you are away.... probably no... (but its one hell of a conversation piece with all sorts of fun!!)
Is it a viable alternative to on-grid living? ....
My opinion.....
Wait for it...
NO.... (Not if you have all the resources at your doorstep and the costs are not exorbitant....)
Is it viable to off-grid living? ....
My opinion.....
Wait for it...
YES .... (Damn....Have I been standing to close to the exhaust and inhaling too many fumes?)
If there is no grid connection for you, if you are out in the backwoods/desert/middle of bugger all and your day consists of trying to stay alive and make yourself a little more comfy for the cold night ahead.... This could be a viable way of doing it... Cheap too if you have access to WMO/WVO that people are begging to get rid of... The actual maintenance on these units is reasonably straight forward, only basic tools are required and if you know what you are getting into and can make provision for it, this is probably a way to go about it.. As a straight genhead, not worth it - as a cogen system, definitely worth it.... as a sole source of energy.... get 2... for the day you break an arm/leg and cant go and attend to the daily running chores... If possible, run it hard for a short period and use some form of energy storage to keep you going the other 22hrs of the day.... In suburbia, retrofitting the average power-hungry household....well... only you can decide.....
