Author Topic: Any one setup for CHP capturing your exhaust heat?  (Read 1316 times)

gadget

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Any one setup for CHP capturing your exhaust heat?
« on: January 25, 2021, 03:09:00 PM »
I've been looking through lots of CHP videos and haven't found anyone capturing waste exhaust heat of there listers. Is there a reason to avoid it? Condensation issues?

cujet

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #1 on: January 25, 2021, 04:59:50 PM »
Diesel engines produce plenty of exhaust soot. Cooling the exhaust can add to the problems and reduce heat transfer. There are a number of folks who have done it, and to the best of my knowledge, made it work.

CHP is the holy grail, that's for sure.

Interestingly, with an efficient diesel generator and the use of an efficient heat pump, it's well within the possibilities to get more heat into a building than simply burning the fuel at high efficiencies would produce.

Today, a good "air source" (conventional, like a mini split) heat pump can produce 3x more heat than energy it consumes. Put another way, 2000 watts running power required, 6000 watts of heat produced into the building.

Add in a combined heat system with a well configured diesel of 35% efficiency, and one could, without much difficulty, pump in an additional 3000 watts of heat from cooling and exhaust, producing 9000 watts/30,000 BTU of heat, or 2.5 tons of heat.
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saba

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #2 on: January 27, 2021, 01:01:30 AM »
Hello gadget

Actually I am busy welding something together now. I am busy with yanmar chp I was using a poolheater from stainless steel  that was working pretty good.  Due to design flaws fro my side the intake cracked so I am trying to make something myself.
https://www.behncke.com/en/erwaermung/qwt-100/

With the lister som 6-1 I was running a pipe cooler which was working brilliant except for clogging up pretty fast. Pipes were approx 8mm diam and was a big mess to unplug all the pipes. But exhaust temp was same as cooling water temperature as long it was clean.

I am making something new now but takes lot of time and something of the shelve is expensive for just a hobby project. And I still need to find out how it behaves.

Greetings Bernhard

AdeV

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #3 on: January 27, 2021, 07:52:45 AM »
I started playing with an idea for my Lister 6-1 engine. I have some thick-wall aluminium tube of about exhaust size (no idea where it came from!), into which I cut an 10mm round groove using a form tool on the lathe. I wrapped some microbore copper pipe (the sort we use in the UK for central heating systems) into the groove. Filled it with water & fired up the engine. With a load on the engine, the water in the microbore pipe boiled in about 2-3 minutes IIRC. At the time, I didn't have any cladding over the pipe, so it was 50% exposed to air; nor did I have any thermal compound between the pipe and the aluminium tube to improve contact surface area; so I've no doubt the system could be hugely improved with very little extra effort.

I haven't gone any further with that experiment, but I've no doubt I could get a good supply of hot water from it; and it gets hot MUCH faster than the engine block. In fact, I'd be tempted to circulate the hot water through the block initially, until that gets up to temperature, before extracting the heat for personal use...

I'll take a couple of photos of the lash up later, if anyone's interested.
Cheers!
Ade.
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1x Lister CS Start-o-Matic (complete, runs)
0x Lister JP4 :( - Sold to go in a canal boat.

cujet

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #4 on: February 09, 2021, 07:00:04 PM »
 Just a thought, but an EGR cooler from a larger diesel pickup truck or conventional diesel truck is one possible way to recapture exhaust heat. There are a great variety of units available, some of which are designed for high flow and are cleanable.

The use of a functional catalyst upstream of the EGR cooler will result in less EGR cooler contamination and more heat.



 

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cujet

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #5 on: March 11, 2021, 02:13:03 PM »
Shameless bump for you lazy forum members :)

This is interesting stuff, we should do something with it.
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mikenash

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #6 on: March 17, 2021, 06:15:10 AM »
I started playing with an idea for my Lister 6-1 engine. I have some thick-wall aluminium tube of about exhaust size (no idea where it came from!), into which I cut an 10mm round groove using a form tool on the lathe. I wrapped some microbore copper pipe (the sort we use in the UK for central heating systems) into the groove. Filled it with water & fired up the engine. With a load on the engine, the water in the microbore pipe boiled in about 2-3 minutes IIRC. At the time, I didn't have any cladding over the pipe, so it was 50% exposed to air; nor did I have any thermal compound between the pipe and the aluminium tube to improve contact surface area; so I've no doubt the system could be hugely improved with very little extra effort.

I haven't gone any further with that experiment, but I've no doubt I could get a good supply of hot water from it; and it gets hot MUCH faster than the engine block. In fact, I'd be tempted to circulate the hot water through the block initially, until that gets up to temperature, before extracting the heat for personal use...

I'll take a couple of photos of the lash up later, if anyone's interested.


Ade, a lot of folks here don't have access to a lathe or machining skills

But, if you wanted water that was just "hot" in terms of, say, pre-heating a HWC or the like - then you're only playing with something like 55 degrees C.  And, if you kept the "cooling" water flowing so that there wasn't static water "sitting" and overheating - then the plumbing to heat water to that extent could be much much cruder - something that is the tech equivqalent of some i/2" copper pipe wound around some alloy tubing and slathered with high-temp silicone . . .

AdeV

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #7 on: March 17, 2021, 03:06:31 PM »
But, if you wanted water that was just "hot" in terms of, say, pre-heating a HWC or the like - then you're only playing with something like 55 degrees C.  And, if you kept the "cooling" water flowing so that there wasn't static water "sitting" and overheating - then the plumbing to heat water to that extent could be much much cruder - something that is the tech equivqalent of some i/2" copper pipe wound around some alloy tubing and slathered with high-temp silicone . . .

Totally agree - the reason I did machining was because I had a machine ;D If you're only looking for ~50C or  so, and you're not in a big hurry, you can easily extract that from the cooling circuit, I had a surplus (insulated) indirect hot water tank I used for that purpose. IIRC, it took about 40-60 minutes with the engine loaded, to reach 50 degrees in my tank. This was only an experimental setup, I'd need to add diverters and a radiator to start shedding unwanted heat, something I never got around to.

The other reason I used a microbore pipe (rather than just a water jacket heat exchanger, for example) was speed: You get a small amount of very hot water very quickly The downside is you have to keep pumping cold water in, or risk pressurising any system in very short order. However, time and other constraints curtailed experiments, and I've never quite got back around to it.
Cheers!
Ade.
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1x Lister CS Start-o-Matic (complete, runs)
0x Lister JP4 :( - Sold to go in a canal boat.

mihit

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #8 on: May 12, 2021, 11:43:59 PM »
I had to look it up. CHP = Combined Heat and Power.

I really like the idea, since heat is typically considered a waste/byproduct, and normally just dumped...

starfire

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #9 on: May 13, 2021, 08:11:31 AM »
I tried this years ago, decided not worth the trouble. The amount of heat in the exhaust is reduced rapidly under partial load. This is because a diesel always ingests a complete cylinder full of cold air,  and under partial loading, the injection of fuel is just a small part of the complete power stroke, the excess air steals your heat basically.  Using cooling water to preheat the water arriving at a  normal hot water cylinder is a useful addition, but usually requires extensive plumbing alterations and can feed vibrational noise into the other parts of the dwelling. My Lister uses a car radiator mounted through the wall into my workshop, electric car fan ,so does take some chill off during winter. If your engine runs full load for lengthy periods, it may be worth doing, but for me, not.

scott p

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #10 on: May 13, 2021, 09:53:14 PM »
Interesting post by cujet.

 As far as maintenance and troubleshooting goes seems like a good long term investment to consider a heat pump.

Of course it all depends on the over all circumstances of each area to heat and how much time one is willing to spend building and then working the bugs out of what could become rather complicated.

Heat pump, more or less instant heat and thermostatically controlled to boot.

2000 watts 220 volts around 10 amp. What does a heat pump of that nature cost?


mihit

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Re: Any one setup for CHP capturing your exhaust heat?
« Reply #12 on: May 15, 2021, 06:38:51 AM »
There is a co-gen forum located at
http://www.microcogen.info/index.php
which may be of interest to you

Looks very interesting ,thankyou!