Author Topic: 12-2 Cooling tank/ heat exchanger  (Read 10968 times)

Geno

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Re: 12-2 Cooling tank/ heat exchanger
« Reply #15 on: October 06, 2006, 11:59:11 PM »
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These exchangers can be had on ebay for $50.00 (used) to $150.00 Even the smallest one should be big enough for a 12/2. They’re pressure tested and good to several hundred degrees. Copper tubing can cost as much and there is much less fabrication with the exchanger. I’ve said it before but it’s worth repeating, “my primary engine coolant loop must be as robust as possible”

Good point, but if I understand you correctly, these will require a water pump in the engine coolant loop. Excess copper tubing can also be obtained at a good price.

No, the primary loop is thermosiphon through the hot water rad. The secondary loop through the wood boiler heat exchanger will require a pump of some sort.

Agreed.  It's only an approximation, and one that probably was not based on an engine like our beloved Lister(oid)s. 

Nobody likes to see heat thrown away, especially is you live in a cold climate.  But you get the most out of what you have, you have to design the engine into your entire heating system.  Placing it in the basement and heating the basement with waste heat would at least keep your 1st floor warm.  Beyond that, there's not enough energy to justify the expense of all the modifications.

Personally, I'm in favor of using the accumulated waste heat in a cooling tank to pre-heat the domestic water entering the house before it goes to your domestic water heater.  I'm amazed at how common it is to take water right out of the cold hard ground and pump it into your hot water tank while you're taking a shower.  If the water could first go through your Lister(oid) cooling tank, you'd save some energy right there and it would cost nothing.

George shows such a setup on his CD

Quinn

I considered putting it in the basement, it is the best way.....for a minute. Then the saftey and insurance ramifications whapped me upside the head. My house is paid off, I don't want to build another. If I'm dead it don't matter.

Great piont. Even without heat from an external source a "pre tank" near the hot water heater/furnace in the basement would get the temp up to what ever the basement is at. My water, directly out of the basement wall, in the winter, is at least 20°f colder than ambient.

Thanks, Geno

skeeter

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Re: 12-2 Cooling tank/ heat exchanger
« Reply #16 on: October 07, 2006, 12:20:07 AM »
I agree. Some of that 50% I hastedly attributed to the exhaust loss probably is radiant loss from the engine surfaces. I was just trying to work back to make sense of hotater's coolant observation. In my mind at least, the magnitudes assigned to the the mechanical motion (~30% and probably a liittle less) and coolant, somewhere around 20%, make some sense. Since I'm new to these, I can't make a good judgement on radiant loss.

What I was trying to decide, and I believe I have, is the expense of the added plumbing outside the engine room, worth it for the heat gain from the coolant. Now, I would have to say definitely not, unless heat exchanging from the exhaust. At this point, that nut is too hard for me to crack. What I will be doing is to use CHP inside the room to heat vegatable oil, along with the radiant heat giving passively from the engine.
PS 12/2 & 7.5kw ST Head
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listerdiesel

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Re: 12-2 Cooling tank/ heat exchanger
« Reply #17 on: October 07, 2006, 08:05:08 AM »
"Glass lined"  usually means a thin layer of spun-in fiberglass that can be re-sealed with a kit from Home Depot.  Cut the tank with a sawzall and not a torch.   :o

As I understand your system, it will only have about three (?) gallons of fluids in it?   And you counting on heat transfer from the copper coil heat exchanger to the 80 gallons of water in the hot water heater?

I'd be interested to know how that works.  My 6-1 produces about 6 gallons an hour of 195 degree water.  Assuming your's is double that it means the three gallons of water will be circulating about four times an hour to start with but will get faster as the heat sink tank heats up...but it should take a while.   :)

We use indirect water cylinder/tanks a lot in the UK for domestic water heating etc., is this the sort of thing you are talking about here:

http://www.viessmann-us.com/web/canada/ca_publish.nsf/Content/Vitocell-V-100-Produktschnitt_ca_english

Peter

Geno

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Re: 12-2 Cooling tank/ heat exchanger
« Reply #18 on: October 07, 2006, 10:42:52 AM »
Al has some interesting, real world observations. I *think* his piping runs are short and its his primary coolant in the loop.

when i hooked up my new 6 1 4k metro i used a 10500 btu per hour unit heater my figures were 10700 btu per hr at 70% load as this engine is supposed to be about 48 or 49% eff. after about 50 hours run time at a 12 amp load that was all the unit heater could do to keep temps under 200. after giving up on the to small unit heater i installed a larger one 55000 btu  i wired up a aquastat on the return to keep the feed temp at 195 to 200  the cal of 1/3 1/3 1/3 is either off by some or the engine is not quite as efficent as they say. now the "rad' is sized ok for all running loads .I have run it at a steady 23 amps and it is ok

Thanks, Geno

skeeter

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Re: 12-2 Cooling tank/ heat exchanger
« Reply #19 on: October 07, 2006, 01:59:19 PM »
Geno - I got it regarding your heat exchanger idea.  Al Rileys observation is interesting, and is something to think about further.
PS 12/2 & 7.5kw ST Head
195 deg. F T-Stats
Motorguard Bypass Filter
xyzer's Dippers
1100 hrs & counting