I wouldn't mess around with the cooling system to get hot water. Rather build a heat exchanger that goes on the exhaust if you want to get hot water. Reason I say this, your system ads to many variables that if broken for whatever reason could seize your engine without cooling. I do love these old enigines though. A reminder of a time where things were built to last and engineering kept simple.
@ZS6JMP I do plan an exhaust heat exchanger, I just haven't figured out what kind yet. Even so, it seems a shame to waste the coolant heat; the output of these engines is (roughly) 1/3rd mechanical power, 1/3rd heat to coolant, 1/3rd heat to exhaust. I may well re-design it to thermosiphon, with a coil to extract heat from the coolant tank rather than relying on pumps, etc. but I also plan lots of monitoring, so it will auto-shutdown if it loses coolant, oil, etc. etc.
@AdeV2 Good design I have seen is to channel the exhaust gas through a stack of small tubes surrounded by a large pipe that encase them, this increase the water/metal contact area. all you now need to do is to channel your water to be heated into the casing pipe and there you have it.....a efficient heat exchanger.
@ZS6JMP The only problem with that sort of heatx is diesels will plug them up with soot. Not too much hassle, you just have to pop the end caps off every once in a while & give it a good clean out. I have bodged together a low-efficiency heatx (just some copper tube wrapped around an aluminium pipe) which I plan to do experiments with, but time is currently short. I hope to do something with it next month or so...
@AdeV2 An idea I have conjured up is to build a oil filled heatx around the exhaust. Pretty much wrap up some copper pipe around the exhaust and encase it with another pipe, seal the ends and fill it with oil. Should in theory work well. IT will provide good heat transfer and one will only have to watch out for oil igniting and secondly provide expansion room for the oil.
@ZS6JMP - If you haven't already, do a google search for "microcogen"; and join the forum of that name. I think you'll enjoy it, and there's plenty of heatex experience on there (some good, some not so good...)
@davev8app Your heat output will be much greater with an exhaust heat exchange system and supply heat quicker. The exhaust will become hot much faster than the coolant water in a tank.
@davev8app No point. The thermal exchange in the exhaust unit will be much quicker and efficient than the secondary coil. Therefore the coil will always be lagging behind the exhaust exchanger in thermal output unless I am missing something.
My previous (as videoed) setup used only the engine coolant to heat an insulated tank of water; it took around 50-60 minutes to heat the whole tank to >50 degrees C with a 2kw load on the engine. The exhaust gets too hot to touch very quickly (within 5 mins), but I don't know how much of that heat I can reliably extract.
The coolant extractor (as per dave's post) is dead easy & can be done without pumps; my exhaust heatx will have to be pumped; a vertical design might still thermosyphon.
@ZS6JMP Yes may be more heat to be had from the exhaust i will fit my SC with a tharmastat, say at 80C as modern engine oil is designed to run at this temp and i only want to run it 4 hours a day so need to get every last drop of heat from it
I wouldn't mess around with the cooling system to get hot water. Rather build a heat exchanger that goes on the exhaust if you want to get hot water. Reason I say this, your system ads to many variables that if broken for whatever reason could seize your engine without cooling. I do love these old enigines though. A reminder of a time where things were built to last and engineering kept simple.
ZS6JMP 11 months ago
@ZS6JMP I do plan an exhaust heat exchanger, I just haven't figured out what kind yet. Even so, it seems a shame to waste the coolant heat; the output of these engines is (roughly) 1/3rd mechanical power, 1/3rd heat to coolant, 1/3rd heat to exhaust. I may well re-design it to thermosiphon, with a coil to extract heat from the coolant tank rather than relying on pumps, etc. but I also plan lots of monitoring, so it will auto-shutdown if it loses coolant, oil, etc. etc.
AdeV2 11 months ago
@AdeV2 Good design I have seen is to channel the exhaust gas through a stack of small tubes surrounded by a large pipe that encase them, this increase the water/metal contact area. all you now need to do is to channel your water to be heated into the casing pipe and there you have it.....a efficient heat exchanger.
ZS6JMP 11 months ago
@ZS6JMP The only problem with that sort of heatx is diesels will plug them up with soot. Not too much hassle, you just have to pop the end caps off every once in a while & give it a good clean out. I have bodged together a low-efficiency heatx (just some copper tube wrapped around an aluminium pipe) which I plan to do experiments with, but time is currently short. I hope to do something with it next month or so...
AdeV2 10 months ago
@AdeV2 An idea I have conjured up is to build a oil filled heatx around the exhaust. Pretty much wrap up some copper pipe around the exhaust and encase it with another pipe, seal the ends and fill it with oil. Should in theory work well. IT will provide good heat transfer and one will only have to watch out for oil igniting and secondly provide expansion room for the oil.
ZS6JMP 10 months ago
@ZS6JMP - If you haven't already, do a google search for "microcogen"; and join the forum of that name. I think you'll enjoy it, and there's plenty of heatex experience on there (some good, some not so good...)
AdeV2 10 months ago
@ZS6JMP you dont have to mess with it just put a indirect coil in the tank
davev8app 6 months ago
@davev8app Your heat output will be much greater with an exhaust heat exchange system and supply heat quicker. The exhaust will become hot much faster than the coolant water in a tank.
ZS6JMP 6 months ago
@ZS6JMP i plan to use both
davev8app 6 months ago
@davev8app No point. The thermal exchange in the exhaust unit will be much quicker and efficient than the secondary coil. Therefore the coil will always be lagging behind the exhaust exchanger in thermal output unless I am missing something.
ZS6JMP 6 months ago
My previous (as videoed) setup used only the engine coolant to heat an insulated tank of water; it took around 50-60 minutes to heat the whole tank to >50 degrees C with a 2kw load on the engine. The exhaust gets too hot to touch very quickly (within 5 mins), but I don't know how much of that heat I can reliably extract.
The coolant extractor (as per dave's post) is dead easy & can be done without pumps; my exhaust heatx will have to be pumped; a vertical design might still thermosyphon.
AdeV2 6 months ago
@AdeV2 I am planning to build a vertical oil filled exhaust heatex with a coppercoil running the water through. Will post a vid when done.
ZS6JMP 6 months ago
@ZS6JMP Yes may be more heat to be had from the exhaust i will fit my SC with a tharmastat, say at 80C as modern engine oil is designed to run at this temp and i only want to run it 4 hours a day so need to get every last drop of heat from it
davev8app 6 months ago
Nice work, when I have a place of my own I plan to do this!
Sounds very nice too, old Lister's will run given any excuse.
steamwally 1 year ago
Very nice job.Love the sound of a lister
mytickets 1 year ago