Sully's Micro Cogen Project - Needs critique and input from you experts.

[Sully]

Hey everyone.  Third post so I'm very new here.

I'm looking to buy or build a new microcogen that is responsible for a lot of house duties on a large sailboat.

This boat is used for well to do guests who come and vacation on it.  My full time job is bringing these people on vacation and I am currently still building our next charter boat (full time). 

I was considering a bunch of different propulsion ideas, but outboards won out due to weight and drag considerations.  For you boat folks, this is a very fast boat - 20 knots under sail. 

Now to the microcogen.

Let me explain, first, what I'm trying to do, then explain how I am thinking I can do it.  Please let me know where I'm wrong and where I can do things in a more simple and efficient manner in terms of meeting the needs.

The Needs

*Air Conditioning
*Heat
*DC Power
*Fresh water from salt water (desalinization / reverse osmosis)
*Hot Water

*Quiet System
*Not Looking Like a Junkyard - Must Be Elegant

The Plan (needs your expertise!)

*3 Cylinder Kubota Diesel with sea water heat exchangers for cooling and for cooling the mainifold (off the shelf item) - nearly all accessories mentioned below should be run from belts off the flywheel side to get full rated power out of a very small engine.
*Twin 3 ton Sanden compressors to run air conditioning or maybe a reverse cycle heat pump - should be able to kick in a control to run at a moderately high RPM when compressors are on, but slow down a bit when they are off to save fuel.
*1/2" chiller and heater lines to run to 6 different zones on the boat
*Local fans to control amount of heating or cooling in each zone
*Huge alternator to provide DC amps out, run at the flywheel for efficiency - when running, should be able to kick in a control that varies the RPM based on what kind of draw the inverter needs... just like the control on a Honda EU2000.  Would be nice if it auto-started based on battery charge state.
*Belt driven high pressure water pump for watermaker (reverse osmosis) system
*Coolant heat exchanger to make hot water via standard marine hot water heater (they have a coolant loop for heating)
****Possibly use the exhaust heat to heat the boat, but not so sure about that.  Probably have reverse cycle heating with the air conditioning compressors... need input here.

I know, it's one complicated beast, but all of these systems are required for the boat.  They are all available off the shelf as individual AC powered items, but the total weight of the items, plus the total weight of a large generator to power them would be less than ideal.   

The objects in this design are both weight savings and fuel efficiency.

Well, what do you all think? 

Any input from this brief introduction? 

My weak points are:

1)  Setting up a reverse cycle heat pump - I can set up marine refrigeration and air conditioning, but have never made a reverse cycle system
2)  Connecting all of these to the flywheel output - do they make a huge pulley set I could attach to the flywheel and have all of these pumps laid out everywhere running from belts?
3)  Controls - I'd really like the Honda EU2000 "Eco throttle" type control when making power and then also would like to have the engine run efficiently as the air conditioning compressors kick in and out.  A regular governor type speed control would be best running the watermaker pump.  Lots of controls, but I do have some experience... just very rusty.  I made controls for a NASA spacecraft in the 1990's.

Any advice?

Are there any threads I need to look at on here you'd recommend?

Thank you very much in advance.  This thread will be long and we can all participate in the design if you like that kind of stuff. 

[sailawayrb]

I think I would start out by first figuring out (and minimizing where possible) my total electrical loads (AC and DC power) and mechanical loads (AC, RO, etc)...and you might want to pad this number by X% so as to have some design margin.  That will determine what size alternator and engine you will need.  I find that all too many people start acquiring engines/alternators without first doing this most basic of pre-planning.

Then you can think about how best to extract the resulting heat available and relative to what's required for hot water and general heating.  As you say, this has all been done already, many different ways, and is commercially available.  So your effort is more about sizing what you need, developing an overall generic integrated design solution that accomplishes the mission, and then selecting all the specific off-the-shelf components required to complete the mission within your budget.  And keep in mind that the marine environment is very harsh on electrical/mechanical equipment and there is good reason why marine equipment is pricely.  Sometimes going cheap on critical marine equipment can be false economy...especially if this is bluewater mission with lee shores...

If you don't have a copy already, you might want to get Nigel Calder's "Boatowner's Mechanical & Electrical Manual".

Bob B.

[LowGear]

Build an ass kicking DC electrical system and invert as needed.

Electric outboards? 

I went on Black Beards SCUBA cruise (that's how I sold it to her).  We knew it was time to get up when they turned the air conditioner off to cook breakfast.  "Twice the fun - Half the money".

Casey

[rcavictim]

I made controls for a NASA spacecraft in the 1990's.

Welcome aboard Sully. Awesome! Did you make the outside doorbell for the International Space Station? 

The US allegedly spent a million bucks developing a pen that would work in zero G.  The Russians solved the problem with a lead pencil.  In similar spirit of saving money the outside doorbell on the MiR was an old brass cowbell and a cast iron striker with a stainless steel cable so the unshielded rays of the sun wouldn't rot the cord.  Didn't matter that sound waves won't travel in a vacuum although the cosmonauts might have heard it through the station's bulkhead by conduction.   If you buy any of this we need inventive people like you! 

[Sully]

Build an ass kicking DC electrical system and invert as needed.

Electric outboards? 

I went on Black Beards SCUBA cruise (that's how I sold it to her).  We knew it was time to get up when they turned the air conditioner off to cook breakfast.  "Twice the fun - Half the money".

Casey

Casey, this is a real possibility, if I can find some appropriate, submersible electric motors.  In that case, I wouldn't have to invent a micro cogen setup at all.  This is probably the most simple, but the propulsion of the boat, of course, has to be rock solid.  I'd have to find some 15-20KW AC motors and generators (probably putting out 3 phase) to run them.  They also have to be thin (like a submersible pump) so as not to get in the way of the props they would be turning. 

I am looking into this option right now, which might save me countless hours of putting together a reverse cycle heating and cooling system.  Then, I could buy one off the shelf, using the DC gen to power and invert as you were saying.

Yes, Bob.  It is all about sizing and finding off the shelf parts, but I am not entirely sure where to do so.  Where do you find the type of things that I was mentioning? 

*Multiple crankshaft pulleys for taking power off the flywheel side?
*Controls for engine/throttle?
*Components for a hydronic reverse cycle heater?

Do you guys have any particular places you buy things at that you like?

I do have a handle on my electrical loads though...

I am trying not to sound too cocky (unsuccessfully), but I could write that Nigel Calder book.  It's for people just starting out with boats.  I've owned an ocean going sailboat for more than 20 years now and have actually owned about half a dozen.  I've done ABYC compliant upgrades to all and do all my own work.  I also live full time on these charter boats and I'm 100% responsible for all maintenance work.  I'm a 100T Master with STCW-95, sailing endorsement, etc... etc... Nigel Calder is for beginners.  I've already analyzed my power consumption needs as the first step.  This is a very advanced topic for boaters, which is why I stopped in to visit you folks.  A lot of people on boating forums just have no experience with anything but buying complete systems off the shelf. 

I am building a very advanced boat right now - 20 knots under sail - using vacuum resin infusion techniques, etc...  I need to keep as much weight off the boat as I can to keep the performance.  Performance is part of what I'm selling to the charter guests.

Anyway, I will explore making some electric outboards.  They don't make any large enough for this boat off the shelf.  I would normally need twin 30HP marine diesels for it. 

Thanks for the input, guys.  I'll be back... when I'm finished taking a second look at the outboard vs electric outboard issues.  Previously, I found that the weight of the generators, plus electric motors was too heavy as compared to either just diesels or just gasoline powered outboards.  I will revisit that again and post back.

[squarebob]

Here is a 30HP electric outboard

http://www.gizmag.com/30hp-aquawatt-most-powerful-electric-outboard-motor-in-the-world/18511/

[Lloyd]

http://www.microcogen.info/index.php?topic=709.0

Think DC power plus Bats, now think Multi volts plus bats.

4-8 kw DC power,  house loads.

10-18 Kw prop loads

How much Heat?

How much cooling, refer/freeze not in included?

A/C think rolling piston variable speed DC.

Propulsion Drive think DC.... all the gear doesn't have to be under water

L

Build an ass kicking DC electrical system and invert as needed.

Electric outboards? 

I went on Black Beards SCUBA cruise (that's how I sold it to her).  We knew it was time to get up when they turned the air conditioner off to cook breakfast.  "Twice the fun - Half the money".

Casey

Casey, this is a real possibility, if I can find some appropriate, submersible electric motors.  In that case, I wouldn't have to invent a micro cogen setup at all.  This is probably the most simple, but the propulsion of the boat, of course, has to be rock solid.  I'd have to find some 15-20KW AC motors and generators (probably putting out 3 phase) to run them.  They also have to be thin (like a submersible pump) so as not to get in the way of the props they would be turning. 

I am looking into this option right now, which might save me countless hours of putting together a reverse cycle heating and cooling system.  Then, I could buy one off the shelf, using the DC gen to power and invert as you were saying.

Yes, Bob.  It is all about sizing and finding off the shelf parts, but I am not entirely sure where to do so.  Where do you find the type of things that I was mentioning? 

*Multiple crankshaft pulleys for taking power off the flywheel side?
*Controls for engine/throttle?
*Components for a hydronic reverse cycle heater?

Do you guys have any particular places you buy things at that you like?

I do have a handle on my electrical loads though...

I am trying not to sound too cocky (unsuccessfully), but I could write that Nigel Calder book.  It's for people just starting out with boats.  I've owned an ocean going sailboat for more than 20 years now and have actually owned about half a dozen.  I've done ABYC compliant upgrades to all and do all my own work.  I also live full time on these charter boats and I'm 100% responsible for all maintenance work.  I'm a 100T Master with STCW-95, sailing endorsement, etc... etc... Nigel Calder is for beginners.  I've already analyzed my power consumption needs as the first step.  This is a very advanced topic for boaters, which is why I stopped in to visit you folks.  A lot of people on boating forums just have no experience with anything but buying complete systems off the shelf. 

I am building a very advanced boat right now - 20 knots under sail - using vacuum resin infusion techniques, etc...  I need to keep as much weight off the boat as I can to keep the performance.  Performance is part of what I'm selling to the charter guests.

Anyway, I will explore making some electric outboards.  They don't make any large enough for this boat off the shelf.  I would normally need twin 30HP marine diesels for it. 

Thanks for the input, guys.  I'll be back... when I'm finished taking a second look at the outboard vs electric outboard issues.  Previously, I found that the weight of the generators, plus electric motors was too heavy as compared to either just diesels or just gasoline powered outboards.  I will revisit that again and post back.

[pressurepro]

Wow I think I just got battery cable envy

[Sully]

Here is a 30HP electric outboard

http://www.gizmag.com/30hp-aquawatt-most-powerful-electric-outboard-motor-in-the-world/18511/

Aside from being incredibly overpriced and not available for sale in the USA, there is a little boating detail that must be understood in order to talk outboards...

There are basically two kinds of boats:  Planing boats and displacement boats.  There are more, but we'll keep it simple.

Planing boats are what the vast majority of outboards are made for.  These outboards have a small diameter prop that spins very fast in the water and is optimized for high speed while the boat is above the water.  90%+ outboards are made for this type of boat.  The Aquawatt is also made for this type of boat.

All sailing vessels are what is called a displacement boat.  This means the boat's hull does not plane on top of the water.  It stays sunk down in the water, just like it would at rest, even when going full speed.  These types of boats require large diameter props that turn at a slower rate, which gives way more torque and low end power.  It is necessary to use that kind of prop on a displacement boat.  The Aquawatt does not work on a displacement boat.  Outboards like the Honda "Power Thrust" and Yamaha "High Thrust" and Mercury "Bigfoot" are the types you can run on a displacement boat.  They have geared down lower units that turn the prop more slowly and have larger diameter props. 

For that reason, there are no suitable electric outboards in existence.  I would have to build it. 

[Sully]

OH MY GOD LLOYD!   

Thank you!  That's exactly the type of thing I was envisioning.  Let me take a good read through that entire thread and I will post back here to answer your questions.  Beautiful! 

http://www.microcogen.info/index.php?topic=709.0

Think DC power plus Bats, now think Multi volts plus bats.

4-8 kw DC power,  house loads.

10-18 Kw prop loads

How much Heat?

How much cooling, refer/freeze not in included?

A/C think rolling piston variable speed DC.

Propulsion Drive think DC.... all the gear doesn't have to be under water

L

Build an ass kicking DC electrical system and invert as needed.

Electric outboards? 

I went on Black Beards SCUBA cruise (that's how I sold it to her).  We knew it was time to get up when they turned the air conditioner off to cook breakfast.  "Twice the fun - Half the money".

Casey

Casey, this is a real possibility, if I can find some appropriate, submersible electric motors.  In that case, I wouldn't have to invent a micro cogen setup at all.  This is probably the most simple, but the propulsion of the boat, of course, has to be rock solid.  I'd have to find some 15-20KW AC motors and generators (probably putting out 3 phase) to run them.  They also have to be thin (like a submersible pump) so as not to get in the way of the props they would be turning. 

I am looking into this option right now, which might save me countless hours of putting together a reverse cycle heating and cooling system.  Then, I could buy one off the shelf, using the DC gen to power and invert as you were saying.

Yes, Bob.  It is all about sizing and finding off the shelf parts, but I am not entirely sure where to do so.  Where do you find the type of things that I was mentioning? 

*Multiple crankshaft pulleys for taking power off the flywheel side?
*Controls for engine/throttle?
*Components for a hydronic reverse cycle heater?

Do you guys have any particular places you buy things at that you like?

I do have a handle on my electrical loads though...

I am trying not to sound too cocky (unsuccessfully), but I could write that Nigel Calder book.  It's for people just starting out with boats.  I've owned an ocean going sailboat for more than 20 years now and have actually owned about half a dozen.  I've done ABYC compliant upgrades to all and do all my own work.  I also live full time on these charter boats and I'm 100% responsible for all maintenance work.  I'm a 100T Master with STCW-95, sailing endorsement, etc... etc... Nigel Calder is for beginners.  I've already analyzed my power consumption needs as the first step.  This is a very advanced topic for boaters, which is why I stopped in to visit you folks.  A lot of people on boating forums just have no experience with anything but buying complete systems off the shelf. 

I am building a very advanced boat right now - 20 knots under sail - using vacuum resin infusion techniques, etc...  I need to keep as much weight off the boat as I can to keep the performance.  Performance is part of what I'm selling to the charter guests.

Anyway, I will explore making some electric outboards.  They don't make any large enough for this boat off the shelf.  I would normally need twin 30HP marine diesels for it. 

Thanks for the input, guys.  I'll be back... when I'm finished taking a second look at the outboard vs electric outboard issues.  Previously, I found that the weight of the generators, plus electric motors was too heavy as compared to either just diesels or just gasoline powered outboards.  I will revisit that again and post back.

[Sully]

http://www.microcogen.info/index.php?topic=709.0

Think DC power plus Bats, now think Multi volts plus bats.

4-8 kw DC power,  house loads.

10-18 Kw prop loads

How much Heat?

How much cooling, refer/freeze not in included?

A/C think rolling piston variable speed DC.

Propulsion Drive think DC.... all the gear doesn't have to be under water

L

Hi Lloyd.  I am happy to find someone who has done something similar to what I'm looking to do. 
I am still not convinced about the diesel electric propulsion at this point and my go with outboards.  I have to do a weight analysis on that choice.  Even the guys on the electric boat forum suggested that my usage pattern would be better suited to outboards, if I wanted to props clear of the water when sailing.  So, I'll take the DC power for propulsion out of the mix for now.

Heat:  36,000 BTU
Air conditioning:  3-4 ton.  Have had mixed estimates.  My estimate was 4 ton.  Other people say 3 ton.

Refrigerator and Freezer:  I prefer these run from solar, since I do not want to chew through batteries, cycling them to run those loads.  I also prefer not to do daily generator runs to support refrigerators and freezers.  I prefer those run automatically, so I'm not a captive slave to my boat.  I can leave for a week and still come back to well frozen items when that runs from solar.  Have owned boats with both setups.  Much prefer the automatic, always on, no maintenance solar refrigeration.

A/C:  When you say "rolling piston", do you mean a scroll compressor?  I think that's what you are saying.  They make those belt driven as well, but it's a lot easier to buy that stuff off the shelf, I guess. 

The whole microcogen idea was to use the diesel engine to run the huge loads that solar can't handle.  Solar can handle a microwave, a hairdryer, refrigeration and freezers, etc... What solar can almost handle, but not quite, is air conditioning and heat.  I had envisioned that the small diesel could be kicked in for HVAC purposes, then figured I'd add the high pressure pump for the watermaker and a high output alternator for an extra battery boost if I get behind on solar. 

That is the main idea behind the microcogen... as a supplement to the solar system that runs all electric.  Just kicked in for extremely huge, long time period loads and for odds and ends like watermakers. 

[Tom Reed]

My thought is to make it one big system. When you're not on the boat the only loads will be refrigeration and the solar will handle that.

[Sully]

Still at it here. 

Boats can be fairly complex, since one decision affects the next and I have to minimize weight above all else.

Looking more closely at this microcogen, I am thinking of just making it into a big DC power source and running everything through inverters.  That way, solar can do some work and the micro diesel can do some work. 

Is it possible to buy or make a throttle assembly for the diesel that allows it to up the RPMs in response to a load coming online, like a Honda EU2000 generator does?  Does anyone know about these types of control systems?

[Sully]

Ok, I asked a pretty hard question about the throttle control.

Here is a more simple question:

Does anyone know where to find good deals on used diesels - especially 10-14HP marinized diesels?

[Tom Reed]

Craig's list in the SF bay area frequently has diesel generators pulled from sail boats.