Previous in Forum: Innovative Cooling System   Next in Forum: Naming the Forum
Close
Close
Close
26 comments
Commentator

Join Date: Jun 2009
Posts: 88

Heat Cogeneration

08/15/2009 5:23 PM

Hi,

I am looking into doing a project on heat cogeneration. The basic idea of the project is to harness the heat energy that comes out of trucks and trailers exhaust and use it for some useful purposes ( i.e heating the truck cabins/sleepers) during winter. I was wondering whether anyone here has such experience? or is there any good books that you recommend that might be useful. I dont have any experience in this and would like to give it a try... Thank you

Register to Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Oct 2008
Posts: 42369
Good Answers: 1683
#1

Re: Heat Cogeneration

08/15/2009 5:30 PM

" trucks and trailers exhaust" Trailers don't produce exhaust.

The losses incurred by your system would be huge!

No one wants exhaust gasses running through the sleeper, so, you'd need a heat exchanger.....................................................................etc.

Register to Reply
Commentator

Join Date: Jun 2009
Posts: 88
#2
In reply to #1

Re: Heat Cogeneration

08/15/2009 5:34 PM

I'm sorry, you are right.it is trucks and not trailers..and the idea was to run the exhaust through the heat exchanger as you had mentioned..

Register to Reply
Guru

Join Date: Oct 2008
Posts: 42369
Good Answers: 1683
#3
In reply to #2

Re: Heat Cogeneration

08/15/2009 5:42 PM

Heat exchangers cost a lot. And aren't that efficient at low temps.

Try another field.

Register to Reply
Guru
Popular Science - Weaponology - bwire Hobbies - Car Customizing - New Member

Join Date: Dec 2007
Location: Upper Mid-west USA
Posts: 7498
Good Answers: 96
#7
In reply to #2

Re: Heat Cogeneration

08/17/2009 12:57 AM

Actually you were correct at first as many trailers are equipped with heating or cooling units (TCU) temperature control units.

__________________
If death came with a warning there would be a whole lot less of it.
Register to Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 23263
Good Answers: 418
#4

Re: Heat Cogeneration

08/15/2009 6:14 PM

You do not co-generate heat by doing that with a HX from the exhaust gases, heat is generated only be the IC engine.

Why not tap into the cooling systems to pull the heat, its alot more efficient, cleaner, do not have to worry about the HX fouling or deteriorating do to the noxious and corrosive gases.

phoenix911

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Register to Reply
Power-User

Join Date: May 2009
Location: CORDOBA ARGENTINA
Posts: 157
Good Answers: 4
#5

Re: Heat Cogeneration

08/15/2009 6:24 PM

It was done on the old reliable CITROEN 2CV and 3CV cars

Since 1948 up to 1990

A air chamber enclose the exhaust pipe , a damper divert hot air to the cabin or run it utside over the front tire

http://en.wikipedia.org/wiki/Citro%C3%ABn_2CV

See details at this photo

http://en.wikipedia.org/wiki/File:Citro%C3%ABn_2cv_engine.jpg

__________________
devitg
Register to Reply
Guru
Hobbies - Fishing - Old Salt Hobbies - CNC - New Member United States - US - Statue of Liberty - New Member

Join Date: Mar 2007
Location: Rosedale, Maryland USA
Posts: 5198
Good Answers: 266
#17
In reply to #5

Re: Heat Cogeneration

08/17/2009 12:35 PM

The old VW Beetle heated the interior in similar fashion.

__________________
Life is not a journey to the grave with the intention of arriving in a pretty, pristine body but rather to come sliding in sideways, all used up and exclaiming, "Wow, what a ride!"
Register to Reply
Guru

Join Date: Jun 2009
Location: South of Minot North Dakota
Posts: 8378
Good Answers: 774
#6

Re: Heat Cogeneration

08/15/2009 6:28 PM

So doesn't your present cab heater do that already by using the waste heat from the engine?

Ideally you don't want to remove too much heat from you exhaust system anyway. If you do and you have longer exhaust pipes you will get severe condensation and soot build up when operating at low power outputs. When you do run the engine hard that soot will ignite and you have the same effect as a stack fire in a fire place but only going down the road blowing hot sparks all over the place as you drive!

I have seen propane powered gen sets used by off grid people with heat exchangers on the exhaust system. They used it to further capture the waste heat off the engine and then transfered that heat from the engines cooling system and exhaust system into big hot water holding tanks for domestic use.

By running their home efficiently off of batteries and only starting the gen set when higher power demands required it they got very cheap electricity and heat for their homes at the same time.

Basically the normally inefficient IC engine became a very efficient furnace with electricity as a secondary byproduct. No fuel energy was wasted that way.

Register to Reply
Guru
Popular Science - Weaponology - bwire Hobbies - Car Customizing - New Member

Join Date: Dec 2007
Location: Upper Mid-west USA
Posts: 7498
Good Answers: 96
#8

Re: Heat Co-generation

08/17/2009 1:04 AM

I expect you refer to static vehicles and it's far more efficient to use small auxiliary engines to provide cab heat; what point to run a 600 HP engine cab heater...

Possibly your concept may be relevant if used upon static engines such as for driving gen-sets, pumps, drilling units, compressors etc..

__________________
If death came with a warning there would be a whole lot less of it.
Register to Reply
Anonymous Poster
#9

Re: Heat Cogeneration

08/17/2009 1:59 AM

Trap it in compressor tanks then filter it through water tanks then use the polluted water to feed hypoxia water to algae tanks then create biofuel from the algae. Better yet; if you can set up a community infrastructure that feeds biofuel stations during winter. Additional vegetation and bacteria from the sewerage management could aid the algae after generating heat as its own biomass (because of the nutrient composition).

Or just exhaust into a scoop for a ceramic labyrinth hopper with metal rods running through a heater tank but try not to disturb the vehicle exhaust and it's tuned backpressure. Perhaps a heavy element liquid or micro metallized liquid would be better for longer retention of heat.

For a faster lighter vehicle a turbo like flywheel running in liquid that increases activity due to the heat might be better. Running the entire exhaust through a series of heat transmission flywheels may have been an option the original designers in Diesel's and Kettering's time should have thought of along with a particle trap to empty. Especially considering the brass and copper techniques of their time, but look at the Curie's and it's obvious consideration comes when it's needed!

But basic set up would be a pipe run as encasement over the exhaust system driven by a spare turbo fan and then ducted into a air pathway coil or chamber through the floor of the trailer.

Register to Reply
Participant

Join Date: Dec 2008
Location: Hungary
Posts: 4
#10

Re: Heat Cogeneration

08/17/2009 3:11 AM

The good old beetle (vw kafer) had heating like this also.

The heat up was quick, but always had exhaust smell, -getting the intake air from the engine cooling fan.

and couldn' generate enough heat to defog the windshield

(this was only the lack of pipe insulation)

__________________
Gergo Erdei
Register to Reply
Guru
United Kingdom - Member - Hearts of Oak Popular Science - Paleontology - New Member Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2005
Location: In the Garden
Posts: 3389
Good Answers: 75
#11

Re: Heat Cogeneration

08/17/2009 4:23 AM

NO No No! did I say NO!!! ?

Truck engines are running cooler and more efficiently these days and it's getting harder and harder to fine enough exhaust temperature to regenerate the particulate traps - even when you have upstream catalysts to "magically" reduce the combustion temperature of the soot.

Whilst Active Regeneration systems have their place (on applications which don't ever reach the 260°C exhaust temperature for ~40% of running time), adding them increases fuel usage.

So whilst your idea sounds like a good one, it has huge implications in other areas of the trucks' balance of fuel ecomony and emissions compliance.

The heat exchanger could be downstream of the trap, but from experience the gas temperature there is 200 - 300°C. Not sure if this is high enough grade heat for your purposes.

The poster who comments about back pressure is correct - who don't want to be messing with that - it would upset the engine's calibration, resulting in higher fuel use, increased emissions, and reduced component lifetime. The corrosion comment was also correct. The only way to circumvent these issues would be to use the existing exhaust pipe as part of the heat exchanger - making it very inefficient as it would have a low surface area to volume ratio.

In addition, trying to find the space on a truck to add a heat exchanger would be extremely difficult. I know they're big vehicles, but believe, the space for componets is limited - the more weight you carry in components the less weight you can carry in cargo.

Concentrate on stationary engines and domestic boilers (leaving enough heat to ensure bouyancy and thus unforced draught exhaust).

__________________
Chaos always wins because it's better organised.
Register to Reply Score 1 for Good Answer
Anonymous Poster
#12

Re: Heat Cogeneration

08/17/2009 4:51 AM

Simply invent a" decombustor" and convert the exhaust back into the fuel from which it originated.Use this fuel to run the engine.Of course, you will never get quite all of the fuel back, so this is not perpetual motion.

Call your next case.

Register to Reply
Anonymous Poster
#13

Re: Heat Cogeneration

08/17/2009 8:55 AM

Easier to run a duct from the current truck heater under the floorboard and up into the cabin. Don't forget to insulate the outside portion of the duct.

Register to Reply
Anonymous Poster
#14

Re: Heat Cogeneration

08/17/2009 9:34 AM

hi

there is a company , i forget the name , that sells a regen . wrap around the sewage pipes to preheat water before the water heater. you could probably use that with glycol and store the glycol in a tank for later use. it could protect the exhaust but stainless steel is expensive (dont use copper ...) and the cost is probably too high.

be carefull on CO , no smell, no tell, ...

i will be using a similar system for regen. off a marine motor for preheating shower waters, combined with solar.

one may want to consider in the near future, the use of solar on top of the trailers ... especially if you develop an exhaust regen. system, the pumps and tank will already be there.

good luck

Register to Reply
Member

Join Date: Aug 2009
Posts: 5
#15

Re: Heat Cogeneration

08/17/2009 9:40 AM

Good morning:

I have read some of the other responses and yes heat is lost and hard to make use of in a reasonable way. Various automobiles in their engineering have utilized such efforts.

What is actually important is that you are asking the questions and perhaps not with the vehicle solution is that you will find other opportunities. We have similarly looked and ended up fitting our house with a system using ground thermal mass (not a geothermal heat pump) to provide summer airconditioning and winter pre heating. We need a fan assembly for air transport but that is all.

We all need to think and share thoughts. I laud you for that

GVW

Register to Reply
3
Guru

Join Date: Dec 2005
Posts: 1602
Good Answers: 19
#16

Re: Heat Cogeneration

08/17/2009 9:51 AM

Many small aircraft also use small HX packages to transfer exhaust gas heat to cabin heat. Biggest issue is that as they age corrosion pin-hole leaks allow CO into the cabin and cause drowsiness, sleep, and (if not caught soon enough) death! I believe most truck cabins and sleepers do take a safer means and use engine coolant to heat cabins and sleepers. I highly doubt the industry would have any price motivation to change to using engine exhaust heat for cabin heating.

Spend some time looking for a more profitable idea to research and develop. I do not want to sound too discouraging, but I also do not want you to lose time researching a dead end alley.

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply Good Answer (Score 3)
Anonymous Poster
#18

Re: Heat Cogeneration

08/19/2009 12:13 AM

What I saw in advanced studies executed with the assistance of a University in Australia, is a system of energy recovey from : trailer's braking.

The last time I saw this development it was in the process of: patents searches etc . and : full scale trials. The energy captured was through electric accumulation ( there are others which used hydraulic reservoirs which in turn do help the tractor-truck/trailer combination on re-starting after traffic lights. ( watch out all of them mean added weight. Personally I have always felt they should be universally applied to : trains - however my background not including : mechanical engineering I have had to " shy - off "and watch ! )

As suggested by the previous contributor I suggest you stick to above suggestions . They are far less : dangerous,

Labor Omnia Vincit

Register to Reply
Guru
United Kingdom - Member - Hearts of Oak Popular Science - Paleontology - New Member Engineering Fields - Mechanical Engineering - New Member

Join Date: May 2005
Location: In the Garden
Posts: 3389
Good Answers: 75
#19
In reply to #18

Re: Heat Cogeneration

08/19/2009 8:35 AM

The idea of regenerative braking is very well known - I doubt the folks you saw found it easy to get a patent. Electric trains use this technology, storing energy going downhill to use going up the next incline.

Wait for PWSlack to wander by again - CR4's resident train expert!

__________________
Chaos always wins because it's better organised.
Register to Reply
Guru

Join Date: Dec 2005
Posts: 1602
Good Answers: 19
#21
In reply to #19

Re: Heat Cogeneration

08/20/2009 8:29 AM

Most transit lines (with frequent stopping) will regen a lot of electricity during the early stages of deceleration into a station. In the US not many all-electric trains for freight service that can take advantage of regenerating and reusing electricity on long down-hill grades. Might be an idea for someone to research.

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply
Guru

Join Date: Feb 2007
Location: Israel
Posts: 2966
Good Answers: 24
#23
In reply to #19

Re: Heat Cogeneration

08/20/2009 10:13 AM

"...energy going downhill to use going up the next incline..." - As done today by Toyota Prius

Most DC motor can in fact be switched to act as a dynamo. If the load (friction) on the motor reverses to a (external) push, it can be detected by the impedence to switch from a motor to an electricity generating dynamo.

Trying to patent this is futile: Michael Faraday could crack a rib, laughing in his grave

Register to Reply
Guru

Join Date: Dec 2005
Posts: 1602
Good Answers: 19
#24
In reply to #23

Re: Heat Cogeneration

08/20/2009 6:13 PM

Ya got me!

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply Off Topic (Score 5)
Guru

Join Date: Feb 2009
Location: Tamilnadu, India
Posts: 836
Good Answers: 42
#20

Re: Heat Cogeneration

08/19/2009 12:48 PM

Vanuta,

Good concepts. Your idea will be workable based on the following options for late heating use..

The flue gas energy can be used to heat thermic oil, high density organic oils stored containers kept in mobile insulated chambers. They retain higher temperature without being evaporated. This insulated hot oil energy stored can be later used for room heating and other purposes with suitable attachments.

Try out a mini model test and go ahead. Regards.

__________________
Nature is so graceful and naked. Human possession is ridiculous.
Register to Reply
Guru

Join Date: Feb 2009
Location: Tamilnadu, India
Posts: 836
Good Answers: 42
#22
In reply to #20

Re: Heat Co generation

08/20/2009 8:50 AM

Saline water is also being tried as heat retention fluid. Try with proper specific gravity by your own experiments.

__________________
Nature is so graceful and naked. Human possession is ridiculous.
Register to Reply
Commentator

Join Date: Jun 2009
Posts: 88
#25

Re: Heat Cogeneration

08/22/2009 12:20 PM

Guys,

I was thinking more in the lines of static vechicle that is running pumps at very high horse power..i'm sorry, i should have been clearer in my earlier statment.

Register to Reply
Guru

Join Date: Dec 2005
Posts: 1602
Good Answers: 19
#26
In reply to #25

Re: Heat Cogeneration

08/24/2009 9:58 PM

No problem. In either case, I still doubt the economics of the added equipment versus the energy saved would encourage anyone to make the extra investment for adding the equipment to the vehicle. If I am wrong, let me know. (But you won't be the first to tell me I'm wrong!)

__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.
Register to Reply
Register to Reply 26 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (5); bwire (2); devitg (1); English Rose (2); erdeigergo (1); GVW (1); lyn (2); ozzb (1); phoenix911 (1); Ried (4); s.udhayamarthandan (2); tcmtech (1); vanuta (2); Yuval (1)

Previous in Forum: Innovative Cooling System   Next in Forum: Naming the Forum

Advertisement