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Discussion Starter #1
It seems silly to just throw-away all that good heat energy. Is there some way to capture & store it?

I was thinking maybe I could strap a small brick in the engine compartment, such that it can become a nice hot 170 degrees. When I arrive home, I could carry the brick into my TV room & have a nice constant heat source all night long.

Not too practical though,
carrying a brick indoors every day.
Is there a better way to
capture said heat energy
& convert it to something useful?

(Maybe cook my evening supper on the engine block?) :lol:
 

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Discussion Starter #3
Build a heat pump that sits low to the ground.

Park your nice hot car over-top of the heat pump. Turn on heat pump.

The heat pump will suck the heat out of the engine & into the house.

.

Actually, it'd probably be easier to just put the hot car into the garage. The heat will eventually heat the garage & then make its way through the walls and into your house. That would work especially well if you have a bedroom over your garage. (Vice-versa, in summer, you'd want to leave the car set outside, to keep your home cool.)
 

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Two technologies are already being investigated.

BMW is looking at using the heat from the exhaust to run a small ‘steam’ engine. For the heat available the steam could be from something other than water with the boiling temp adjusted to suit the exhaust temperature. I have also heard of this idea applied to a sterling engine.

http://www.greencarcongress.com/2005/12 ... ping_.html

Another idea is to use the waste heat to charge a phase change salt. The salt is a liquid that can change to a solid and release heat. Recharging the system with heat resets the system. This would allow the de-frost and cabin temp to come up almost immediately. This can also be applied to the engine temp and with a different storage medium the cat could be quickly warmed up to reduce cold start emissions.

The problem with this system is that a short trip will deplete the heat reservoir (you can’t use just half the energy, once it starts all the material will change phase). So you need to get the car up to operating temp every trip.

Several years ago I saw a Toyota mini-van with a similar system connected to the A/C. The A/C would freeze water in a matrix (looked like bubble wrap with water in the cells). When the van was parked with the engine off the A/C would blow air through the matrix to cool the cabin for up to an hour, without running the engine. This was an application more specific to the Japanese usage of there vehicles (they drive on the week end for pleasure and sight seeing, they take the train to get to work). I was thinking this might work well for cars with auto stop, you could still have cool air at long stop lights.

By the way, for a patent to be valid you can not reveal your idea to the public until you have submitted the application for the patent. So the brick idea is a public technology now.
 

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The sad truth is that 99 percent of patents do not show a return on the cost of the patent. Now the other 1 percent. :D

The BMW system has a 15 percent energy recovery. It is complex, scavenging high and low temperature heat in two loops.

Parking the car in the garage works, but only if the above ambient energy stored in the engine/coolant is greater than the below ambient temperature stored in the rest of the body. (Salty slush on the body is an excellent phase change cold storage media.) ;)
 

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Here is a little Teaser!

Saving the waste heat.

I am actually doing a Prius thermos mod to one of my Insights as we speak. I shall keep you all updated with a full write up later.

The Prius Thermos fitted to some of the models in colder climates basically saves hot engine coolant between runs and dumps it into the engine on the next cold start, reducing warm up time and improving economy etc. It has been discussed on here before, but I don't think anyone has actually done it yet ;) Until now that is!

As the Prius Thermos is impossible to get in the UK, I am using a 3L Emsa President pump pot stainless steel vacuum flask, This is an excellent model with some useful fittings as you can see from these few pics. I have a pump, and am now waiting for a 3 way valve to help finish the sytem.

I carried out some heat retention tests with the flask, and when filled with 95C water it was still above 45C 3 days later, about the same performance as the Prius flask.

I was saving this, but I will let you in on some of the details now.

My test system will be very simple with one thermometer showing the temp of the coolant in the flask. The pump and valve will be controlled by a simple push to make switch and one minute one shot timer.

Operating sequence is this, get in car on cold morning, check thermos temp on gauge, if hotter than ambient press button to transfer contents to engine. When you stop engine after your run press button again to transfer hot coolant from block to thermos. Easy. This can also be done automatically later with a simple circuit.

Here are a few teaser pics.
http://www.solarvan.co.uk/insight/Thermos01.jpg
http://www.solarvan.co.uk/insight/Thermos02.jpg
http://www.solarvan.co.uk/insight/Thermos03.jpg
http://www.solarvan.co.uk/insight/Thermos04.jpg

These two pics show how the Prius system works.
http://www.solarvan.co.uk/insight/Preheat.jpg
http://www.solarvan.co.uk/insight/Storage.jpg

These two pics show a crushed Prius thermos. (Thanks to Mike Dabrowski)
http://www.solarvan.co.uk/insight/crushedpriusflask.jpg
http://www.solarvan.co.uk/insight/cutopenpriusflask.jpg

I am also incorporating a low power 12V heater in the flask to help maintain the contents temperature. The could be run from the mains like the Insight block heater but would be hundreds of times more effcient. Just a few watts would maintain the temp in the flask, and 12v is a lot safer outside than 110v or 240v here in the UK. You could power this heater from a solar panel in the summer :)

Anyway I am away on hols next week so probably be at least a month before system is up and running, a lot depends on finding a suitable three way valve.

Peter UK :)
 

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Discussion Starter #8
b1shmu63 said:
Parking the car in the garage works, but only if the above ambient energy stored in the engine/coolant is greater than the below ambient temperature stored in the rest of the body.
"This sentence does not parse." (Brings back memories of Zork.) Uh... if your engine is at ~180 degrees, and your house is at ~60 degrees, the heat will flow out of the engine & into your garage & eventually your house.
 

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Re: Here is a little Teaser!

retepsnikrep said:
I am actually doing a Prius thermos mod to one of my Insights as we speak. I shall keep you all updated with a full write up later.
Peter please do ! :)
And start a new thread in the Mod & Tech forum. I've looked into this option too. Should be enough space in the 12v battery area to fit.

New Prius parts are nearly $1000 USD for the thermos and 3way valve and pump :!: :shock: So far all the recyclers I've checked with don't have a clue of what I'm asking for.


Troy: Read about the laws of thermodynamics. Maybe Kip's reference to the "body" wasn't clear. He ment the car's body. Lots of thermal mass that is well chilled from being outside.
 

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Re: Here is a little Teaser!

retepsnikrep said:
Saving the waste heat.

I am actually doing a Prius thermos mod to one of my Insights as we speak. I shall keep you all updated with a full write up later.
I'm very interested to hear about this.

Been thinking about it for years but as with most projects on the Insight (new battery tray, MIMA, some gauges, battery relocation, etc.) that I have planned it's been on the back burner until I get the RX-7 done.

My basic plan was to use a thermos filled with wax, then a long coil of copper tube inside through which the coolant circulates. That way there are no valves and pumps involved but once the engine begins running the cold coolant will circulate through the hot wax and become warm much faster. Probably not effective for the first start of the day at -30 degrees, but certainly for each successive start.
 

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I went as far as buying 2 stainless steel 1.5 liter thermos bottles that were on sale. I considered using washing machine valves rewound for 12 volt activation. I never figured out an effective way to seal the thermos bottles without creating a thermal bridge. Yes, keep us informed!
 

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that is just peiltier effect modules on the exhaust ... if you have the money and or time... I've seen people make them for exhaust systems , as well as radiator systems.

No off the shelf option as far as I know... just custom stuff.
 

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Unless the peltier effect you refer to is completely different from the PC Computer applications than I am used to then this is not the peltier effect. The peltier effect (unless I am mistaken) involves using electricity to pull heat away from one source and send it to the other side of that source. It's used on computers in heat sinks.

This is different because it involves using heat to generate electricity... sort of a backward peltier effect.
 

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those same peltier effect modules you use in cooling a PC also work in reverse...

The semiconductor setup will generate a current any time there is a difference in temperature between one side and the other... or you can create a difference in temperature by supplying electricity and the device will pump heat from one side to the other.

you can see this effect if you have those PC peltier effect modules hot on one side and cool on the other... and you check them with a multi meter... the larger the temperature difference between he sides.... the more power you get ... up to the limits of the device itself.
 

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Put on a turbo. That will use exhaust energy to increase efficiency. Increased pressure will improve combustion and increased intake temperature would decrease the amount of fuel needed to bring the cylinder up to operating temperature each cycle. Although my understanding of thermodynamics may not be exactly right here.

This would be an efficiency benefit as long as it doesn't mess anything up.

The turbo could also be sized for top end performance rather than low end torque for obvious reasons. As long as you run low boost (<5 psi) you could most likely get away with not being intercooled. I saw a guy turbo an insight online once for performance rather than economy so it has been done.
 

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Keep in mind that any turbo also creates exhaust backpressure due to the turbine. Something never comes from nothing. Turbochargers aren't going to do much for efficiency unless the engine is designed to take advantage (ie. Miller cycle).

The new Prius uses waste exhaust heat to help speed up engine warmup. A coil of coolant is wrapped around a heat exchanger.
 

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I found this trying to learn more about the topic.

"Oh, and let's not forget Autospeed's series on "The Story of Turbo'ing a Hybrid Prius" (1st gen. model.)

Where the author concludes:


Quote:
""So it’s been lots of work and there have been a helluva lot of problems to overcome along the way – but now, finally, what’s the turbo Prius like on the road?
In a word – fantastic.
The turbo NHW10 Prius now has better than standard fuel economy. And performance? Well, the key aim has been realised – country road hill-climbing performance has been completely transformed.""

He points out that, not surprisingly, the car's CVT contributes to the gains because it permits the revs to stay lower for a given road speed.

Parts 1 through 5:

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I'm vaguely aware of a couple of Honda Insights that have also been turbocharged."

here is the link Article: adding a turbo to improve efficiency - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com
 
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