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Off grid lodge - Various low tech - high tech solutions


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Especially on galvanised pipe . You've got to grind it off , the fume aren't good for you and the weld doesn't  flow very well. Stick weld I take it? Try grinding the initial weld back a bit and get all the flux off, then turn up the amps on the welder and go over the initial weld with nice slow wide runs. If you change a rod then again clean the flux and over lap the weld.

But having said all that I'm sure I'm preaching to the choir. 

Maybe the next time you go past an exhaust shop get then to run over your welds with their MIG welder and save some frustration.

Edited by seant
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  • 4 weeks later...

I tried grinding and welding and grinding and welding and grinding and welding but couldn't get the weld waterproof so I gave up on that idea. After hunting around through all sorts of pipe fittings I can up with something that may work. It needed so high temperature gasket maker to completely waterproof it, but it is on the water side so I hope it holds. This is actually more of a mockup so I can measure the heat flow and see if it is a worthwhile exercise to spend more on a pump and plumbing.

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I thought I would take in the head to get the valves seated while I was about it, as they were leaking a bit, bit unfortunately the engineering place found a crack after they had cleaned it up, right between the eyes! I'm now waiting for a new head before I reassemble.

 head.thumb.jpg.09ac695d208337ca9d2b7ce201ab4844.jpg

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New head, heat exchanger installed, so time for a test. The generator was producing about 1kw, its sunny today so not much to do. The heat exchanger takes 3.2l of water. I ran the generator for about 15mins and raised the water to boiling point. So by my calcs, that,s 4.2 KJ/kgC x 3.2kg x 80 degrees C is 1075kj of heat. Divide by seconds to get to watts and I am catching 1.2kW of heat. Is that correct?

That is actually higher that I though I would get, so it would be worthwhile to circulate that water through the geyser.

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I also found an old cast iron radiator in my neigbour's junk heap which I am refurbishing to add into the house heating system. If anyone else has any of these please let me know, I have two rooms that still need radiators.  I figure that by catching all of this waste heat, I have doubled the efficiency of the engine at least.....

 

rad.jpg

Edited by DeepBass9
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Test no 2. I have the water from the heat exchanger thermo -siphoning into that drum on top of the drum on top of the drum. Eventually when I am finished building (if ever) I will have a solar geyser on the roof close by, and then run a circulation pump whenever the generator runs. I'm just running it as a test for leaks now. When the first cloudy cold front comes through, I'll give the Lister a good 4 or 6 hour run under a high charging load and see how that heats the water. I think that drum is about 120l.

My eventual idea is to have 2 x 150 litre tube geysers in series, with the heat exchanger and a small electric element on one of the geysers, so a hot bath or shower is at least an option in the depths of winter.

 

 

heat.jpg

Edited by DeepBass9
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I'm quite pleased with this, I was just running 4 heating radiators as well as heating water from the waste heat of the engine. At the same time it is powering the house and charging batteries, and using only a litre or so of diesel per hour.   Great stuff!

 

If I find its not making enough heat, I'll upgrade to one of these https://www.junkmail.co.za/farming/generator/western-cape/boland/wellington/lister-blackstone-6-cylinder-engine-collectable/71557c0bb539408199eb976a454e9724

Edited by DeepBass9
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  • 1 month later...

I have two more 300W panels on order and I'll try and install them at the weekend. I will then have 4 strings of 3x300W panels. Each pair of strings has its own MPPT since they are at different angles. 6 panels are at about 35 degrees on true north, and the the 6 will be at about 10 degrees also true north. 

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My new panels are up! So I now have 3600W nominal power in 4 strings of 3 into 2 MPPTs, since the arrays are at different angles. 

I have been playing around with a Raspberry Pi and home assistant and have it up and running on our network. I don't have any wifi switches as yet so have just set up some of the weather type of stuff. I'm going to try and use 'darksky' to get cloud coverage to switch the pool pump and geysers off if it is cloudy, and the sun angle looks like it will be very useful to switch loads on when the sun gets high enough in the sky.

Had anyone managed to read data from a BMV 712 using bluetooth? Or do I need to get a USB cable?

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On the low tech side I managed to unleash the full 8 hp from my Lister. I had only managed to get about 3.1kW (measured at the inverter) previously, and that with a lot of bogging and black smoke. At the weekend the exhaust valve stuck open which was peculiar as I have just replaced the head, but it turns out the only thing I had not stripped, cleaned, replaced or reconditioned was the rockers, of which the exhaust one had stuck. So after cleaning 60 years of who knows what out of the bushes, I can run it now at up to 4.2kW, without the smoke and mechanical complaints. The valves must have been closing too slowly with some leakage.

In theory that engine is 8hp at the crank, minus 10 to 15% for altitude gives about 7hp, which is 5.2kW. So after losses through the belt and generator etc, 4.2kW out of the inverter is quite acceptable.

I run it now about every morning to run the electric heater under my desk. I get a real chill in my bones in the morning, must be getting old.

Edited by DeepBass9
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  • 4 months later...

After 3 months I had to fire up the genny this morning. It was cloudy all day yesterday, and the forecast says the same for today. My batteries were at 60% this morning, with little odds of charging at all due to the low cloud and drizzle. The wind generator is making 100-200W from time to time in the gusts so not really helping.

Over the past 3 months I have been saving up all the used sunflower oil from making chips etc, and filtering it for the generator. I poured about 8 litres into 10 litres of diesel so I am now running on about 40% biofuel.

The generator is charging batteries at a constant 25A now, and powering all of the house loads so it runs at a constant 2kW load more or less.  To get the batteries to full will still take about 8 hours running as I am 185 AH down. I could push up the charging amps and run at a higher load, but if you start using the microwave and kettle then it starts to overload the engine and it starts bogging and blowing black smoke from unburnt fuel. On my inverter it is a PITA to change the charging parameters as you must change the parameter, then do a reset which switches everything off for 30 seconds, so all computers etc go off so I rather don't change it very often.

Maybe the sun will help a bit later.

Edited by DeepBass9
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