I am starting this thread to document my progress with this project. I am also copying my first post on the subject 18/02/07 to this thread to give the background. Peter
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.
These two pics show how the Prius system works.
These two pics show a crushed Prius thermos. (Thanks to Mike Dabrowski)
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.