Solar VO heating

Collecting, filtering and dewatering of WVO SVO vegetable oil. For Biodiesel producers too.

Moderators: SunWizard, coachgeo

Postby WyoSam » Wed Mar 12, 2008 12:33 pm

After further study, it appears my idea of using a direct oil solar collector as the first stage in my WVO particle separation will fail as the particle sediment will settle in the pipes. So I’m back to the hotbox design for that initial heating and separation.

As I mentioned, my new processing facility has no electricity. I estimate my converted to vegoil diesel generator will burn .5 to .75 gallons per hour to process WVO. I was looking at, rather than use the generator, how about solar collectors to deep cycle batteries? Since my primary use of electricity would be only two out of every 10 days, could I store electricity during the down days in deep cycle batteries and use heavily during the process days? Specifically, if I use three 75 watt 12 volt panels could I collect and store enough amps over 8 days to run electric heat and pumps for the two? My napkin estimate say yes, am I missing something…or dreaming?

Here’s the figures;
A 75 watt panel puts out 6.25 amps per hour. Three panels makes 18.75 amps/hour
Storing at only 5 hours a day for eight days would store 750 amp hours in 4 deep cycle batteries.

My heat/pump draws under 16 amps per hour at 115 volts. With 48 hours of run time it would draw 768 amp hours. Consider the two run days would still also charge the batteries, this should be close, yes/no?

Thanks again,

Sam
Vegistroke V3
WyoSam
 
Posts: 29
Joined: Wed Mar 05, 2008 11:56 am

Postby Johnno » Wed Mar 12, 2008 6:06 pm

Burbarian
I doubt you will ever generate enough pressure to rupture a panel because fat blocks a tube. The panels are much sronger than that.

WyoSam
Sorry but you are missing something here. Using photovoltaic panels to make electricity to use for heating is the most complicated and expensive way possible, due to the inefficiencies of converting to electricity storing in batteries etc. Keep your valuable solar electricity to run pumps and lights.

I dont know if I made it clear but my panels have water in them. The water circulates by thermosyphon action through poly pipe wrapped around the drums in a spiral fashion. Yes I know it could be more efficient with copper pipe welded on or something like that, but the bucketloads of heat available more than makes up for any inefficiencies

I find this method way simpler than welding fittings to the drums and running oil through the panels. No sediment in panels, no water settling there and then spoiling dry oil, no unfiltered oil caught up there, and I can heat part full drums.
Also no leaking oil from the numerous joints on the solar panel side. Or 200 litres on the ground when a joint pops off from excessive heat. :oops:
My small leaks are just topped up now and again with a 2 litre bottle of tap water.
My systems total cost would be under the cost of one 75 watt panel and can heat 200 litres of oil from 20 degC to 55deg C in one day with no electricity needed at all. I am redesigning it all at the moment and should be able to heat any one of four 200l drums.
:)
Johnno
Johnno
 
Posts: 5
Joined: Mon Mar 10, 2008 2:25 am

Postby David » Wed Mar 12, 2008 7:15 pm

If you have a generator, You have heat and plenty of it.

If the genny is water cooled, you could use a FPHE with the coolant water to heat the oil same as a vehicle.
If the Genny is aircooled, you could make yourself up a HE to capture the copious exhaust heat either as a replacement for the original Muffler/ Exhaust for max heat extraction or just wrap a tight coil around the engine and exhaust itself.

With a generator IC engine, you have 3 times the amount of heat output as you do electricity but you have them all together. Don't bother trying to minimize electrical use up to the capacity of your generator, The more load you put on it the more heat you get as well!

I just bought a small Changfa style Diesel engine and am making up a HE style exhaust for it to heat oil or water depending on what I want to run through it.
David
 
Posts: 333
Joined: Thu Mar 06, 2008 4:12 am
Location: Sydney Australia

Postby SunWizard » Wed Mar 12, 2008 7:43 pm

Your calcs are close for the solar, but it would be a very expensive way to do it. You would also need a 12v to 110v inverter which are not cheap for ones that will last.

You would need lots of antifreeze solution if you do a water loop, so if that leaks out it makes an expensive mess also.
YVORMV - Your veg. oil results may vary.
95 Dodge Cummins 4x4 SVO WVO conversion.
81 Mercedes 300D- stock and happy on V80/D20 blend.
Low fossil net zero house- 100% solar power and heat.
SunWizard
Site Admin
 
Posts: 1723
Joined: Mon Dec 11, 2006 2:53 pm
Location: N. Colorado

Postby John Galt » Wed Mar 12, 2008 8:23 pm

You would need lots of antifreeze solution if you do a water loop

That's an easy one, glycerin from biodiesel is excellent antifreeze, non toxic too.
John Galt
 
Posts: 526
Joined: Tue Mar 04, 2008 9:17 pm
Location: Coldest North America

Postby Burbarian » Wed Mar 12, 2008 9:50 pm

WyoSam, I'm with Sun and Johnno on this one. Using expensive photovoltaics to charge expensive deep cycle batteries then using an expensive inverter to convert the inefficiently generated and stored electricity for heat is just.. wrong.

With the simple addition of a healthy amount of insulation on the exterior of your storage/heating tank, the solar heat input becomes cumulative. You'd get in the ballpark of 5x gain in efficiency at the least by using solar heat directly instead of the battery scenario, and with a considerable reduction in cost and complexity. Efficiency goes up with the increase in volume over surface area ratio, so a 275 gallon insulated tote would be more efficient than 5 x 55 gallon drums. And if you use stratified flow where the hot water comes in from the top, you will reduce convection and potentially gain 5 days of heated settling and water separation.

Considering the amount of investment you are contemplating for the photovoltaic system, it would seem to make far more sense to instead use a tiny fraction of your processed WVO to run that generator. And as David mentioned, with a generator you get heat for free.

Johnno: It wouldn't take much to rupture even commercially made solar collectors designed with pumping in mind. A constrained incompressible fluid undergoing thermal expansion exerts tremendous forces. Forces in the same order as say the expansion of constrained water turning into ice rupturing pipes or splitting boulders. This is unlike gas pressure as gases are compressible. With antifreeze solution, this is very rarely a danger as the pipes are unlikely to plug. Congealed oil on the other hand is another matter that deserves study. High pressure buildup in fluidic systems typically causes rupturing of the seals first, causing leaks which relieve said pressure. Leaking past fittings or popping off hoses is also another means of relieving pressure. Granted this is a worse case scenario, and likely biased by some of my own unfortunate experiences working with hydraulics in construction equipment. :)

David: What model Changfa? I've been using a 195 bolted onto an 8ft trailer with a 10kw ST generator head for the past 7 years. Originally hopper cooled, I converted it to run its coolant loop through an indoor radiator to help warm the workshop. It's got over 500 hours on WVO/RUG blend. Incredibly noisy beast, and much heavier than it looks.
Burbarian
 
Posts: 195
Joined: Wed Mar 05, 2008 12:14 pm
Location: Vermont

Postby Burbarian » Wed Mar 12, 2008 10:27 pm

John Galt wrote: That's an easy one, glycerin from biodiesel is excellent antifreeze, non toxic too.


John, fantastic suggestion! Next time I make a batch of BD, the glycerin won't be going into the gasifier. :)
Burbarian
 
Posts: 195
Joined: Wed Mar 05, 2008 12:14 pm
Location: Vermont

Postby David » Thu Mar 13, 2008 2:52 am

Hello Burb,

The Changfa I got is the baby 165. 3HP I think. I would have ideally liked something around the size you have and especially water cooled for home/ pool heating with co-generation but this one was soooo cheap I couldn't resist grabbing it to add to the collection. The ultimate I have been searching for like 3 years now is a CS 2 Lister. Easily available but I don't want to pay a couple of times what my 300D is worth. :(

I have a 6.5 HP yanmar style already which I bought with a 3" pump attached, again just because the thing was too cheap to pass up. I'll be surprised if the changfa is any noisier than this thing! I played with the exhaust on it only to find that it has to be the best exhaust on any engine I have come across. It emits virtually no noise at all but the clatter from the engine itself is incredible. The Chinese must put effort into making them that way on purpose to keep evil spirits away or something!

The 165 I will probably put to use on a portable air compressor and may equip with an alternator as well.
David
 
Posts: 333
Joined: Thu Mar 06, 2008 4:12 am
Location: Sydney Australia

Postby WyoSam » Thu Mar 13, 2008 4:09 pm

Thanks everyone,

I just got back to town, so I'll comment later.

Sam
Vegistroke V3
WyoSam
 
Posts: 29
Joined: Wed Mar 05, 2008 11:56 am

Postby Burbarian » Sun Mar 16, 2008 1:12 pm

David wrote:I would have ideally liked something around the size you have and especially water cooled for home/ pool heating with co-generation but this one was soooo cheap I couldn't resist grabbing it to add to the collection.


I know exactly what you mean. Local landscaping contractor went belly-up, and due to the housing bust, there is a glut of cheap used construction equipment in the market. I was able to acquire his excavator for $1.8k. It was likewise too good a deal to pass up. Once the weather warms, I'll be doing a rebuild on the tracks and bucket teeth. Too big to bring into the shop, and too cold to work on it outside at the present. Was contemplating digging a pool and insulating it with used foam board between the concrete and the ground, and from air contact by putting it down the middle of a new greenhouse. (actually building a greenhouse around it) For horticultural and tax purposes, it is a 'rainwater irrigation catchment and passive solar heat storage cistern'. And it should do those tasks splendidly. Just have to make sure nobody is swimming in it when the tax man cometh.

The ultimate I have been searching for like 3 years now is a CS 2 Lister. Easily available but I don't want to pay a couple of times what my 300D is worth. :(


Those would be ideal. I've been keeping an eye open for one myself. A 3/1 is available for $2.1k, and though the reputed 50k hours between rebuilds is mighty attractive, I too find it difficult to justify spending that much on a 3hp jenny. Specially since I still have the 195.

I have a 6.5 HP yanmar style already which I bought with a 3" pump attached, again just because the thing was too cheap to pass up. I'll be surprised if the changfa is any noisier than this thing! I played with the exhaust on it only to find that it has to be the best exhaust on any engine I have come across. It emits virtually no noise at all but the clatter from the engine itself is incredible. The Chinese must put effort into making them that way on purpose to keep evil spirits away or something!


With the 195, the intake makes just as much noise as the exhaust, if not more. Muffle them both and the engine proper still produces a very loud clatter. I do like that it is rather well balanced for a 1-banger, with no intention of 'walking' unlike a Lister 3/1. Bolted onto a heavy landscape trailer, it can be towed anywhere power is needed. And yes, the Chinese specially designed them to scare away evil spirits. As well as dogs, cats, wild animals, children, (sometimes the children and wild animals are a little difficult to tell apart) and anybody else who values their hearing!

The 165 I will probably put to use on a portable air compressor and may equip with an alternator as well.

You can install a bypass switch to disable the voltage regulator on an alternator and feed the excitation coil directly from a battery when running. This will allow the alternator to put out high voltage AC. You can then feed that through a high voltage rectifier to produce high voltage DC. Good for welding and charging a bank of series connected batteries all at once.
Burbarian
 
Posts: 195
Joined: Wed Mar 05, 2008 12:14 pm
Location: Vermont

Postby WyoSam » Sun Mar 16, 2008 8:37 pm

Burbarian wrote:WyoSam, I'm with Sun and Johnno on this one. Using expensive photovoltaics to charge expensive deep cycle batteries then using an expensive inverter to convert the inefficiently generated and stored electricity for heat is just.. wrong.


Looking at the storage batteries alone, and considering they recommend having twice the total amp drain needed, (so the batteries would never drop below 50% drain), the price of storage could buy a lister.

This new setup is going to be a long series of baby steps.

Sam
Vegistroke V3
WyoSam
 
Posts: 29
Joined: Wed Mar 05, 2008 11:56 am

Previous

Return to Vegetable oil Collecting, Filtering and Dewatering

Who is online

Users browsing this forum: No registered users and 0 guests

cron