The Listeroid Chronicles-WMO and Other Listeroid Modifications

[38ac]

An old fellow who helped me get going told me that thermostats and thermosyphon don't play together well, most of what I read lends credence to what he told me. Not saying it cant be made to work, it just doesn't come easy.
 I have resisted using thermostats on the few complete set ups that I have installed and instead have placed a gate valve in the lower water port line as the old timer instructed.  It is simple, goof proof once set and lets the system pretty self regulate. yes we run a bit cool under partial loads and a bit hot under heavy ones. The slick operators pay attention to the weather and cover or uncover a portion of the radiator to help compensate.  I don't have anyone trying to run 100s of hours a week so the trade off for a very small loss of fuel efficiency is made up for in KISS. 

[EdDee]

Hi B&D,

There is always a way to get a pump in, in fact I have one that can be used.... I just don't want to!! (KISS principle to the max!)...

Reducing the efficiency of the radiator is also an option, but again, back to the old adage, SIZE DOES COUNT....Lol .... Due to the large temperature range this beast needs to operate in, preferably unattended, I am looking to find a way that if at all possible, even seasonal variances are catered for automatically with as few moving bits as possible... Should I be able to come up with a relatively "ID ten Tee" proof way, it might just be able to benefit all users, in all climates....

Regds
Ed

[EdDee]

Hey 38AC,

Agreed re the Thermo-Syphon/Stat debacle... They do not like to be neighbors in any system.... Agreed, they can work, and do work very well together when u eventually get the kinks out... but, they are not the best under all conditions.... Particularly if the stat gets cooked up beyond its range, it tends to fail closed which can cause big problems in a system that is run by unskilled hands with minimal eyes on... Weather shutters can be implemented on the radiator - think of the old beetle engines for the colder climates... They had Auto-Air restrictors on some models that were temperature controlled... They worked well, but also were one of the first things to fail in the hotter climates... Now, if I can get away from moving parts almost completely, and control fan startup and monitor environment temp at the same time just by using a piece of Ali Bar as a spacer between the radiator and switch.....(I am stuck with a switch and electric fan...My design doesn't let me get away without them..)

The gate valve might still be used initially in my system to control flow, but again, I am not too wild about something that can be messed with causing problems later, like "Oh. is that what it was for.... I thought it was to shut off the water to the building..." ....  .... .... one melted roid and bad mood later....Lol....

Keep it Spinning...

Regds
Ed

[carlb23]

I had the radiator fan fail once on my roid and it overheated and just stopped.  When i went to turn it over it wouldn't budge.  I took off the inspection cover to see if i could see anything (i didn't know the fan had failed at this point and thought maybe the big end bearing went) by the time i got the cover off the engine was free again.

I then discovered the failed fan and knew that it had overheated.  After the engine cooled for a while I started it back up for a few seconds and it ran fine.  Not wanting to take any chances i tore the engine down completely.  Upon inspection I could not find any evidence of damage from the overheating episode.  I put the engine back together with a new set of main bearings just because i had several spare sets and the old ones had a few pit marks in them and the engine is running fine.

[EdDee]

Noted Carl....

That was a close one!! I hope to never go there again.... Been there on a few cars in my foolish years, now the b@lls are smaller and the brain is bigger... I Hope!

Regds
Ed

[EdDee]

Hey Guys,

I might just have found the magic bullet....

Take a look at this: http://www.warriorpaintball.co.za/private/Radiator Switch Heatsink B.jpg ... Simple, easy to do reasonably adjustable and you can custom it to your own needs...

This has taken my head outlet temp from 75C to 85C nominal to 88C to 95C nominal under full load.... By diverting a small amount of air from the fan over the "fins", you can increase the head temp as needed. By splitting it in half (it's a pair of M/F units) you can lower the temp as needed too...

It is made out of 35mm Ali bar stock, 3mm fins/gaps about 5mm deep. One side of each half has a Male 1/2" BSP Thread and the other a Female. The unit screws into the radiator switch socket and the switch in turn, screws into the "extension" .... The combined overall length is about 70-75mm... I have bored it out to minimize the thermal mass and allow it to heat/cool a little quicker minimizing the lag as far as possible... Id is threaded female to suit the temp switch, virtually full length....

I removed the thermostat and housing I made, the temp immediately took a step at stabilizing, albeit at a lower than required level.... Added the heatsinks, one at a time, and the temp rose as needed. The day temp in the lean-to is around the 30C mark, I will check the evening temp and report back as to whether the unit allows for a broad range of ambients as a bonus.... My logic says that if the ambient temp is lower, the heatsink end at the switch will be lower too.... the fan should shut down earlier and minimize the temperature sag on the engine in cool weather.... Hold Thumbs!!

Keep it spinning....

Regds
Ed

[BruceM]

I was very interested to read 38ac's comments on thermostat difficulties with thermosiphon systems.  I've certainly had some trouble with mine.

My thermostat's kept failing after 1-2 years, and too much hot-cold cycling.  Things I've found helpful were reducing radiator area dramatically, restricting coolant flow via ball valve, and increasing the bleed holes in the thermostat to two 3/16" size holes (top and bottom).  This seems to have done the trick.  Radiator area reduction and coolant flow restriction were done with extended full run on an exceptionally hot summer day.  I'm sure it still gulps a bit, thermally, in winter but it has been behaving well.

[EdDee]

Hey VDub,

Here is the circus diagram for all the electrickery you were looking for.... (Auto Changeover Switch):

http://www.warriorpaintball.co.za/private/Auto Changeover Schematic A.pdf

As per the usual, use at your own risk, get a qualified person to check it over, commission and install for you.....

Keep it Spinning!!

Regds
Ed

PS... How it works...
The genset is the controlling factor, there are no frills or fancies. The only luxury item that is used is an overload sensor that I had lying about.

When the gen is off, the utility contactor pulls in and runs mains power to the selected circuits you wish. As soon as the gen starts up, it pulls in the control relay and this in turn drops out the utility contactor and pulls in the gen contactor as well. The 2 contractors are interlinked to prevent both being pulled in simultaneously and thus blowing up your gen head.... The house then has the selected circuits powered by gen, while other circuits in the house such as cookers and ovens etc run off of utility power. Should too many hair dryers, dishwashers, fridges and toasters be turned on simultaneously on the gen circuit, the overload sensing on the gen contactor triggers and the control relay is switched off, reverting to full utility power and bypassing the gen. Once the overload resets(I have set mine to auto reset after 60sec), the control relay is pulled in and the selected circuits go back to gen power... The contractors I am using are 3 phase, but I have wired the contacts on each contactor in series... Should a contact bar burn closed, the other 2 will surely open, giving a redundancy effect and a bit of a parachute, Just in case!...

The changeover when one input drops away is very quick, ups's don't kick in and PC's don't reset, so things seem excellent ...

Choose contactors that are at least 25% or more above your gen outputs capacity, Bigger even, if u can find... remember that the overload trip on a contactor output is 25% on average above what you set the dial for.... it is also not immediate, so allow for that too... the control relay only needs to be rated to switch the current of the coils on the contractors, nominal 5A should do it quite well...

Hope this helps make your live a bit easier!

[EdDee]

Hey guys,

From a warm and dry afternoon to a cold, wet and windy evening... temp  during this afternoon was in the high 20s C and this evening it was a rainy and windy 12C by shutdown... Why the weather report? .... Well, the radiator switch heatsink seems to be doing its job over the mid lower end of the temperature scale... the cooling system has "self adjusted" itself and kept the head temp at around the 90 to 93 C mark without intervention from me at all, and this is with a air temperature swing of around 18C or so. It looks promising so far, but a bit more testing will still need to be done to confirm that it is working to my satisfaction... Don't copy it just yet, let me screw it up first and save you the trouble!

Loads varied from light to maximum design load over the time period tested so far, including overload conditions of 20A plus, at 230V... At no stage did the cooling system boil... it came very close, but just before boiling point was reached(around 97C), the fan started up and held the heat demons at bay...

As a safeguard, I am prepping some concentrated glycol to replace the coolant in the cooling system with... Although the heat transfer properties of the concentrate will be lower, causing a slightly higher head temperature, the benefits I feel, will outweigh this. The primary benefit will be a much elevated boiling point, in the region of 110C to allow for more leeway before coolant gets dumped from the overflow port on the header tank by steam/vapour expulsion..... My header tank and radiator top tank are not large enough to cater for more than a litre or so loss before the heat syphon loop gets broken... Bad things will happen if it does... But hey, if I get it ticking over OK, if the header tank was good enough for a 1600VW, I am sure my roid won't complain!

Enough rambling... Darkest Africa is again dark.... now that Optimus Prime Mover has gone to sleep....

Keep it spinning!

Regds
Ed

PS... contrary to popular belief, I don't have lions roaming the back yard... bushbuck, duiker, waterbuck, porcupines, bushpig and warthog... but no lions.... Damn, I miss them...

[EdDee]

Hey Guys,

Another bit of a report back on the temperature stabilisation...

Today I took a chance and drained off all the coolant from the thump monster, cooked it up and boiled off as much water as I could, without boiling away too much glycol... It panned out at about 40 to 50% by volume of my coolant was made up of water, or at least, that was what I boiled off anyway... My total coolant volume in the monster is around 8L... this I boiled off down to just over 4L in an effort to re-concentrate it...  The deficit I made up of some reclaimed coolant I had lying around.. I then refilled the cooling system with this concentrate and spun it up...

What I have found is that now the temperature is even more stable than before, it fluctuates around 5C from 99 to 104 degrees with no sign of being near to boiling point of the coolant in the system at all... This is with no thermostat, purely thermosyphon, wildly varying loads(the daughters were home and various hair appliances, washing machines and kitchenware was in full employ today)... I must add though, the weather is far from warm, with a stiff breeze... So any hot weather testing will certainly still need to take place.

Going from a 50-50 glycol to 100% glycol has elevated running temperatures by about 8C, but in doing so, possibly because of the higher viscousity coolant, the temperature seesaw is almost nil compared to previous... The added benefit is that now the temperature is elevated a little more, giving a slightly cleaner burn too....

If the temp remains reasonably tolerable in hotter weather, I think I will have the cooling system at its optimum best for my current setup... A good time to stop fixing it would be around about now!

Next project, is the preheater for the injector... I am going to attempt to tap off some unclaimed heat from the cs plug to do all the heating I can,,, It will have to, of course, be somewhat adjustable, to tailor the preheatimg to suit the fuel source that is being consumed at the time....

Enough rambling... Time to find lions.... Lol... or was it a warthog I heard in the back yard....

Kelp it spinning...

Regds
Ed

[mike90045]

Doesn't the injector get pretty hot bolted into the head ?


What's the temp limit for the rubber O ring in the base of the cylinder ?

[EdDee]

Hi Mike,

It does, but I would like to see if warming the fuel just a little more, will improve the burn a bit more... temp of the back of the injector sits around 65 to 75C I guess.. I would like it at 100 or close as possible... that would thin out my fuel oil to around diesel spec at point of injection entry...

The o rings should be well capable if up to around 110 C without any major problems, also with a high glycol mix, I have found rubber work lasts consistently longer than with high water content... also no crusty build up or corrosion too....

Regds
Ed

[EdDee]

Hey guys,

Another day is done, another good quantity of waste gunk burnt off in an environmentally acceptable way.... with benefits!

Lessons learnt today:

Allow for a slow warm up with straight glycol coolant!

This morning I started the thumper and withing 3 minute of cold start I pushed the power output to max overload to see the effect... Quite spectacular actually! .... When glycol is cold, in my case around 8-10C, it is quite thick and syrupy... the thumper managed to get the glycol in the head to boiling point before it could syphon and circulate due to the cold viscosity and resistance to circulation imposed by the radiator and down flow...  about half a litre came galloping out the overflow before I could get a catch bottle in place.... must have been hilarious to watch ... no harm done, circulation picked up and took over shortly thereafter, no other over temperatures were noted during the day, the first part of which was busy processing a batch of fuel... a straight run of around 2 1/2 to 3 hours at the max design load of the system... about 5kw... The rest of the day consisted of average to high loading, intermittently overloaded.....

Directly after fuel processing, max load, I pulled the cs plug to make a minor mod for the fuel heater/injection heater that I am going to make and fit soon... Take a look at the white deposits that have formed after around 250hrs running... pictures to view here: http://www.warriorpaintball.co.za/private/COV Plug Deposits 250hrs WMO

The mod is really minor and easy to do, it consists of a tapped hole 10mm thread about 40mm deep in the cs plug. I have machined the square of the plug nice and flat to make a good heat contact surface for the brass bar to scavenge heat and transfer it to the fuel line... pictures to view here: http://www.warriorpaintball.co.za/private/COV Plug Modifications

I am not going to modify my existing line, that will be maintained as a spare, I will replace the entire line with a new one incorporating the brass heat scavenging fitting should all go well...

I also got a chance to make a small heat exchanger to fit just before the radiator, horizontally, at the top inlet.... pictures of the internals here:http://www.warriorpaintball.co.za/private/Coolant Heat Exchanger

The reason for this exchanger is twofold, one to harvest a bit of waste heat before it gets lost to the radiator, and two to keep the cooling system warm from the heat store via reverse cycling overnight.... an added benefit would be to have just another couple of litres coolant to help stabilise the system temperature a bit more, but this is not part of the criteria at all... Let's hope the effort/reward ratio lands on the plus side!

Right, I am now thoroughly knackered, Monday has just arrived.... can't wait to get into the office for a bit of a rest...

Keep it spinning...

Regds
Ed

[Tom]

Ed, if you want max btu's out of the cov plug, drill into with 2 holes to form a V in the plug. Then tap the holes for your choice of fitting.

[vdubnut62]

Do you think the white deposits are aluminum oxide?  Really nice craftsmanship on the heat exchanger.  I would never gone to the trouble of flattening the tubing.
Ron.