I don't want to add a coolant pump if I don't need to.
My angles and sizes can't change from the drawing, so the only question is, do i need to pump my coolant, or will it thermosiphon?
The rectangle on the left is a radiator with a fan, the top rectangle is a heat exchanger.
The total climb from the lowest point on the radiator up to the lower cooling port is 3"
The total climb from the upper coolant port to the heat exchanger is 28".
The horizontal distance from the radiator to the coolant ports is 48"
Oops, forgot some important info.....
plumbing is 3/4 copper pipe, heat exchanger ports are 1/2" (copper necks down to 1/2" at those points)
6/1 engine.
Did I forget any other relevant info?
Pipe Lines are too small.
Radiator is too low.
Look at the factory 6/1 system. Masters they be.
Casey
If it worked in 1937, it should work for you now. I use 1/2 " heater hose on my GM 90 but my heatex is 48" above the outlet in the head. You could always angle the radiator so the bottom is not below the inlet point. Give it a try. Nothing ventured, nothing gained!!!
Bob
Casey,
I would love to change the shape of my radiator, make the hoses/lines bigger etc.
I know it isn't the best of layouts.
This is the radiator I have to work with.
I can not mount it higher (or I already would have)
The line restrictions are what I have.
Placement is what it is.
I know the 'masters' have put together systems designed to thermosiphon well, and mine is NOT designed well for that purpose.
I considered changing the angle, to raise the lower part of the radiator up, but due to other limitations of space, that is not practical.
There are a million things I could do to change what I have, but right now, the only variable I am looking at is pump or no pump.
If I use a pump, and it fails, I overheat (no comments about auto shutdowns for now please).
If I don't use a pump, and thermosiphon doesn't work...... I overheat.
Bob, your system can get rid of enough heat at full load with thermosiphon only through 1/2" lines?
If so, my system should be OK line size.
The only real question then would be is, would the 3" rise over 4 feet kill the thermosiphon?
If this is the design you are stuck with, and you have no other options, then Mr. Spock would say that the only logical option left to you is to just try it and see if it works.
I'm sure it will thermosiphon. Whether it will do so in a way that will carry away the heat in the quantities that you will be requiring remains to be seen.
Very important notice. I haven't done any of this stuff. I'm shooting from the hip and relying on information I've read over the years on this site and LEF.
Put in two pumps? Higher temperature thermostat on the second pump along with an alarm.
I'd also insulate the hot line and find someway to put a cooling line on the return. I keep seeing some sort of finned line - copper or aluminum.
Have you considered fans for the radiator?
Casey
Brett, in my admittedly limited experience with thermosiphon cooling systems I have only one tip.
If you are using antifreeze in the cooling system, make sure that it is either pre-mix or that you mix the ethylene glycol with water before you pour it in.
Once upon a time, I had a 1947 "B" John Deere with the thermosiphon cooling system. I was going to come a cold snap, and I figured that I would
winterize the old tractor, and since the plain water in it was pretty nasty looking, I drained everything. After draining, I poured the antifreeze in
and then I topped it off with water and fired the Old Girl up. I let it run a while until I noticed curls of vapor/smoke coming off the engine, but the
coolant lines were still cold. It got up to around 230 degrees if I remember right. I had to drain everything back out and mix it in a bucket , then pour it back in. I guess antifreeze is heavier than water and effectively creates a plug against the natural rise of heated coolant.
Sorry for the long winded story..
Ron
Brett, Current setup is 1/2" rad hose from engine to heatex and back. Other side of heatex has 1/2" rad hose, a circ pump, and a transmission oil cooler with a fan to remove the heat. The cooler is a 16 pass with 650 cfm fan. It measures about 12 x 15. With 2 ~1500W heaters and a small battery charger draw on the ST7.5, the engine is working pretty hard and the temp stays at ~ 190oF. The thermostat is a napa 253 195oF unit. I am using RV antifreeze (propylene glycol) as the coolant.
The setup is just like Ronmars pic except the large tank on mine is a 1 gallon jug 1/2 full of liquid !
Fan Question:
Has anyone ever used a couple of low watt computer fans? Really low current and very low noise (just in case the radiator is in another location from the engine).
Casey
Thanks for all the feedback!!
I decided that I didn't want to have to drain my antifreeze/water mixture (mixed before adding as per Ron) if what I did today didn't work.
I put in the pump on the lower side between the radiator and the lower cooling port on the engine.
My hope is that if the pump (taco) dies, it has a chance to thermosiphon. I understand that these circulator pumps will flow when not running.
As of right now, things seem to be running nicely.
I have the engine turning an ST-5 to produce 240v AC
The 240v AC powers a 48v DC power supply putting out about 37 amps at 51.8 v DC.
The DC feeds a set of 4 el-cheapo Sam's Club marine batteries (in series)
Also connected to the batteries are the MX-60 fed by 4 Evergreen 210w panels.
The batteries feed the GVFX-3648.
Between the Sun and the listeroid, I'm feeding 2KW back into the grid right now!!
THANKS GUYS!!!!
Are you running a thermostat on the engine?
Sooo... shut off the pump, and test the theory while you're right there to monitor it, and everything has stabilised.
QuoteSooo... shut off the pump, and test the theory while you're right there to monitor it, and everything has stabilised.
Troublemaker.
Casey
Low watt computer fans are not rated to withstand much heat. Even if they suck cold, and blow cold toward the rad, the heat from the rad may cook them, just try it, and keep an eye on them
Alright already, so turn off the pump. I'm dying in anticipation here. ;D
Ron
Quote from: LowGear on January 23, 2011, 06:23:41 PM
QuoteSooo... shut off the pump, and test the theory while you're right there to monitor it, and everything has stabilised.
Troublemaker.
Casey
Oh ya. ;D
Well, that's what I'd do... ;D
195 degree thermostat, and temperature controlled fan.
Sooooooo..... I unplugged the pump.
Temp climbed up to around 205 and the fan turned on. BUT.....
By the time the fan kicked on, too much coolant was boiling out into the overflow tank. I turned the pump on and it did circulate, and cool down everything and suck the overflow back into the system.
It might run OK if the fan had been kept on full time. Otherwise it was just too late to play catchup.
Next test will to try the fan on full time and unplug the pump and see.
Maybe next weekend when I have more time to play.
Next week......
Same Bat time......
Same Bat channel......
Playing is good.
Casey
Damn I'm impatient........
So, I started with the fan on.
The engine came up to 200, dropped to 170 when the thermostat opened.
Climbed back to 200, dropped to 175 when the thermostat opened......
Did this till it stablized at about 195 (the thermostat temp).
Thermosiphon works with the pump inline, and a 2300 watt load on the ST-5.
Now I can try to figure out a high temp switch which could turn on the pump for extra flow if it gets too hot.
I'm a happy camper with this setup.
Thanks for the feedback guys.
That's great! Redundant system with no-power fail-safe failure mode! Best case scenario.
I wish it were a no-power fail-safe system.
It needs power for the radiator fan (120v ac), and in an overheat situation, it needs 120v ac to turn on the circulating pump.
If the ST-5 were to quit while the engine was running, I am pretty sure it would overheat with no electricity for the fan, or pump
.......... then again, with no load, I don't know what it would do
............... time for another test.
Quote from: bschwartz on January 23, 2011, 09:52:52 PM
Temp climbed up to around 205 and the fan turned on. BUT.....
By the time the fan kicked on, too much coolant was boiling out into the overflow tank. I turned the pump on and it did circulate, and cool down everything and suck the overflow back into the system.
It might run OK if the fan had been kept on full time. Otherwise it was just too late to play catchup.
Next test will to try the fan on full time and unplug the pump and see.
Was it expanding or boiling.....nothing wrong with expansion....a fact of life. I call it an expansion tank....
Quote from: bschwartz on January 25, 2011, 05:57:31 PM
The engine came up to 200, dropped to 170 when the thermostat opened.
Climbed back to 200, dropped to 175 when the thermostat opened......
Did this till it stablized at about 195 (the thermostat temp).
Put a slightly bigger bleed hole in your thermostat and it will climb steadly without the cold dump on a warm engine. It will also allow flow if you did have a stat stick....
Was it expanding or boiling.....nothing wrong with expansion....a fact of life. I call it an expansion tank....
It was filling the expansion tank FAST and there were bubbles in the line...... I think boiling
The engine came up to 200, dropped to 170 when the thermostat opened.
Climbed back to 200, dropped to 175 when the thermostat opened......
Did this till it stablized at about 195 (the thermostat temp).
Put a slightly bigger bleed hole in your thermostat and it will climb steadly without the cold dump on a warm engine. It will also allow flow if you did have a stat stick....
The next time I drain the system, I'll add another bleed hole. Thanks for the suggestion.
I've been using these Grundfos circulating pumps on both my listeroids with no problems, as have two of my neighbors. If you shop, you can buy them at $68 per unit.
http://www.buyplumbing.net/?pg=pd&_i=UP1542F
I set them at the lowest seting, 3 gpm, and forget about it. As for the radiator, check Surplus Center for a 230 V fan. Draws 0.4 amp and you could just let it run or have it switch on and off with a thermal sensor switch.
https://www.surpluscenter.com/home.asp?UID=2009052819530308
https://www.surpluscenter.com/item.asp?item=16-958-A&catname=
Quote from: bschwartz on January 26, 2011, 10:07:03 AM
I wish it were a no-power fail-safe system.
It needs power for the radiator fan (120v ac), and in an overheat situation, it needs 120v ac to turn on the circulating pump.
If the ST-5 were to quit while the engine was running, I am pretty sure it would overheat with no electricity for the fan, or pump
.......... then again, with no load, I don't know what it would do
............... time for another test.
Ah, I missed that part. Must improve my retention skills... ;D
The only thing I would say is to put the heatex vertical right above the radiator inlet. To enhance thermosiphon flow, you want all the heat input going up on one side(cylinder and head). You want all your cooling going down on the opposite side of the highest point in the system. Putting the heatex horizontal at the top might actually stop the flow when you try and transfer heat out at that point. If the plumbing apexed just before the heatex, and then flowed down thru the heatex to the radiator, that added mass of dense fluid created when you draw heat from the heatex would actually enhance the flow...
Small plumbing is not especially a problem, as it dosn't take much flow to move the het from a 6HP engine. The problem is that the drag it creates really works against thermosiphon as there is so little energy available to pump the coolant.
Oh, new thermostat right? If you have a weep hole already, run it a bit, as i have found new thermostats sometimes a little bit "sticky", and will loosen up, and open easier with a little use and some heat cycles under their belts...
Quote from: Ronmar on January 26, 2011, 08:51:15 PM
Oh, new thermostat right? If you have a weep hole already, run it a bit, as i have found new thermostats sometimes a little bit "sticky", and will loosen up, and open easier with a little use and some heat cycles under their belts...
Mine never improved. If you had a pump and a bypass it would rise steadily. The thermostat will not open until it hits it rated temperature. Then it closes when the cold coolant hits it and repeats the cycle until it is at operating temperature. The "correct" size hole will allow enough circulation to prevent the thermostat from opening until it reaches its rated opening temperature........That's my experience anyway. ....
Although nothing is impossible, you may see from this picture some of the difficulties in turning the heat exchanger on end, and moving other things around. The HE is about 4" below the garage door.
Go ahead and laugh at my mess ::) ::) ::)
And for you observant people...... Yes it is fun shooting a game of cricket when the engine is running ;D
rm /
If you tightened up the bottom elbo on the radiator, you might be able to lower it an inch or two, this might give you enough room to put the heatex stood vertically and very close coupled right on top of the radiator. As pictured, I think the thermosiphon flow will probably fall on it's nose when you start taking heat out of the heat exchanger... With those low angles/long horizontal runs and low height in conjunction with the small diameter tube, it is probably just barely getting by now, and won't take much additional resistance to stop the flow. Here is a quick check, hook a garden hose and drain lines to the secondary of the heatex. Get it up and running with thermosiphon flow cooling, and see what happens when you turn the cold water on to the heatex secondary:)
It's funny.....
When I lived in New York, turning on the garden hose, and flowing water onto the ground for a test would seem like second nature.
Now that I live in the desert southwest (New Mexico), I'd have to think of what I will use that warmed water for, so it doesn't just spill on the ground ;D
As for the close couple, I need to take a picture of that side, and you'll see that I just don't have much room to play with due to the reducers.....
There really is no place to go up, as it goes from the reducer 90 degrees to the HE. The bottom looks about the same. I'd need to lower the radiator a good 8 inches (20 cm) to fit the HE, and that would only raise the slope from the lower port. I think that would really kill the thermosiphon. I think if what you say is true about killing it by taking heat away from the system as it is now, I'll just have to turn the circulating pump on. No big loss, just one more thing to go wrong
Is your garage door open all the way in the picture? Can the HE be relocated to the left, past the point of the fully open door to gain some height? Sure might help the situation.
Bob
Nice oil can. Looks like the one that my Grandad had for an old horse drawn McMormick Deering mowing machine. I wonder where that thing went?
I think your project loos nice. You should see my disaster! My wife threatens daily. I just haven't had the heart to go through Dad's stuff and try t organize it.
Ron
Quote from: bschwartz on January 23, 2011, 03:31:07 PM
Thanks for all the feedback!!
I decided that I didn't want to have to drain my antifreeze/water mixture (mixed before adding as per Ron) if what I did today didn't work.
I put in the pump on the lower side between the radiator and the lower cooling port on the engine.
My hope is that if the pump (taco) dies, it has a chance to thermosiphon. I understand that these circulator pumps will flow when not running.
As of right now, things seem to be running nicely.
I have the engine turning an ST-5 to produce 240v AC
The 240v AC powers a 48v DC power supply putting out about 37 amps at 51.8 v DC.
The DC feeds a set of 4 el-cheapo Sam's Club marine batteries (in series)
Also connected to the batteries are the MX-60 fed by 4 Evergreen 210w panels.
The batteries feed the GVFX-3648.
Between the Sun and the listeroid, I'm feeding 2KW back into the grid right now!!
THANKS GUYS!!!!
Bob,
You need to install a taco bell, to warn you if the pump dies. :D