Mimicking Gen3 Prius Exhaust Heat Recovery

[Daox]

Know of any solenoid valves that can flow enough coolant and aren't $100+? I searched mcmaster.com for solenoid steam valves and they are EXPENSIVE.

[Frank Lee]

"...and how they went to using exhaust heat to speed up the warming up of engine..."

My '66 Corvair has that feature! LOL

[basslover911]

And how much faster the coolant heats up? 5 seconds? not worth it... 1 minute faster? WORTH IT

[Daox]

Perhaps I'll do a test tonight. I'll fire up the car in the garage and let it idle. I have an IR thermometer and I'll measure how fast the exhaust pipe heats up. I'm betting its pretty darn quick.

[Noitoen]

Make some kind of moving heat exchanger. To heat up it moves to touch the exhaust and when hot enough, a motor removes the contact, separating it from the exhaust.

[basslover911]

Originally Posted by Daox

Perhaps I'll do a test tonight. I'll fire up the car in the garage and let it idle. I have an IR thermometer and I'll measure how fast the exhaust pipe heats up. I'm betting its pretty darn quick.

That would be awesome because I am contemplating doing this MAJORLY. And not only for the coolant, but the transmission and oil liquids as well.

Let us know pleeease

[tasdrouille]

Originally Posted by Frank Lee

"...and how they went to using exhaust heat to speed up the warming up of engine..."

My '66 Corvair has that feature! LOL

Thinking about it, that's what the cooled EGR on my TDI do.

[Daox]

Originally Posted by Noitoen

Make some kind of moving heat exchanger. To heat up it moves to touch the exhaust and when hot enough, a motor removes the contact, separating it from the exhaust.

Thats pretty much what I was thinking. I have some initial rough sketches. Might as well share them. The top assembly would be soldered together, and with more tubing. It would ride up and down guided by pins or bolts or something, one on each end. The aluminum tube cut in half would help capture more heat and keep the unit smaller and cheaper. It would also allow for easy mounting with a clamp on each end.

[Frank Lee]

Prius does it cuz engine is on/off so much.

Gotta wonder if it warms up much faster than regular stuff from initial start up?

I mean, with thermostats and especially us with grille blocks, it's only a matter of minutes anyway. I bet coolant doesn't even get overly cool with big P&G.

I think it's a hybrid thing.

[Bearleener]

Here's a PowerPoint about a simulation of various auxiliary heating systems.
http://www.vda-wintermeeting.de/file...DA-Handout.pps
The focus was primarily on warming up the passenger compartment faster when you have an efficient diesel engine (not enough waste heat), but there are interesting comparisons on Slides 14 and 15.
Below is Slide 14. The yellow curve is exhaust heat recovery. Doesn't look too great, but on Slide 15 it has negative fuel consumption, i.e. it saves fuel.

I'm thinking an oil heater: a separate water circuit from the exhaust heat exchanger to tubing wrapped around the oil filter. A pump would circulate the water only when desired, greatly reducing additional, unwanted heat at the oil filter when the engine is warm. An overflow reservoir could accomodate the thermal expansion of the coolant-water mix.