New ICE engine for extended range EV's

Cool! it looks like one of those shake lights.

 

Or, one of those "Shake Weights" that actually does something more than make people giggle & blush (wink,wink)!

Could also make an excellent emergency home POWER source!

 

No direct mechanical path. Functionally reminds me a serial hybrid design. That has both advantages and disadvantages.

It does however look like it might be small and light which would be a tremendous advantage. Without a doubt it *looks* cool.

 

I want one!! .... I'll be the test driver!!

 

...seems conceptual at this point...but I wonder what the fuel requirements would be? Any need for conventional 87 octane gasoline in an unconventional engine?

 

i guess without a real engine and testing, this is close to meaningless. nice to know they are thinking about it tho. reminds me of popular science, 99.99999999% of their 'concepts' never happen.

 

Just being the acronym troll:

Your title "ICE engine..." is basically saying "Internal Combustion Engine engine..."

 

What are the disadvantages?

One might be the two-stroke design which tends to be dirtier (lets unburned hydrocarbons exit the exhaust).

GM is planning to use a three-cylinder in its future Volt G2, which has efficiency very close to Toyota's prototype linear engine.

 

which 'gm claims' has efficiency close to toyota's prototype linear.

 

GM claims its electric Volt only needs a 60+ hp three-cylinder engine to keep it moving at interstate speed. (Approximately 15 hp at running rpm of 1500-2000.)

Another thought: Power companies don't use "linear" engines. They all use rotary generators (powered by turbine or traditional engine with output shaft). Perhaps they've found rotary generation is more efficient?

 

One word answer: INERTIA.

 

Power companies use huge systems not 10 hp engines.

 

The OP link doesn't work for FireFox, or least me, but here's one to the original article: Green Car Congress: Toyota Central R&D developing free-piston engine linear generator; envisioning multi-FPEG units for electric drive vehicles
Links to SAE papers are there.

There is a demostration unit. So Toyota has moved beyond the theoretical. Two cycle engine do have higher emissions, but the concern there depends on what the EV range of the hypothetical car means in terms of range extender use frequency.

It is neat, and a production would probably be cheaper than a microturbine. The question I have is how big is it? In order to work as an onboard range extender for what will be a short range BEV, packaging is important. The A1 E-tron PHV concept had a 30mile EV range with about 125miles of extended range. This was accomplished without compromising any of the interior space. This is in part because the range extender was a 0.25L rotary engine that produced 15kW. It was small and light weight. Fitting between the rear wheels.

All we know is that it will take two of these 10kW linear engines for a car similar to the A1 in size. Size, weight, and displacement are probably in the pay articles, and I'm cheaper than Bob.

 

The gm ice is real and in the opel adam, and being tested with US emissions. The linear ice is still in the lab. We normally call that lab only stuff the claim. Can they A) make it reliable for the 200K miles a 3 cylinder turbo is good for. B) make it at the same cost or less including emissions control systems? What about NVH.

Toyota has 43% efficient turbo ice in the lab. I don't know where GM's new 3cyl turbo sits, but probably in the mid to high 30s being 1L they likely give up some efficiency for cost. To me you have a range extender for a prius sized phev (3200 lbs) you really still need at least 70 hp if it is going to make it on hilly highways in the cold. The cheapest way to do this in a small inexpensive ice is a 3 or 4 cylinder. If size not weight is the issue, then a cast iron block, aluminum head with integrated manifold, like ford used in its 1L allows you to shrink it down, and warm up quicker for short ice times.

You likely will be more efficient if you directly drive the wheels, and you need two motors anyway, so having a turbo miller cycle set up, may help manage the torque for easier system design.

Its neat to see some of this tech from the lab, but the emissions piece of it, or the efficiency piece of it, will normally keep it in the lab.

 

why can't we use micro-turbines for power generation in EV?

 

I think that is the problem that the design of this particular ICE is designed to remedy. Yes, normally you would get more efficient (and by 'efficient', I'm assuming you mean highway mpg using ICE after battery depletion) using a primarily parallel setup like the Fusion & Prius vs. a primarily series configuration as in the Volt.

With this setup and a primarily-series hybrid, I think the battery will always maintain sufficient buffer to take care of cold, windy 70mph hills. It could possibly even use fuzzy logic to determine driving habits, plus GPS, weather & traffic reports, and proximity to mountains to determine when and at what power to activate the ICE.

 

Here is why this engine is so important: the primary complaint about the Volt setup is that once the battery is depleted, it will get inferior highway mpg as compared to the Prius. Thus, the Volt is only more efficient gasoline-wise if you can charge frequently; otherwise on long continuous highway travel with no charging opportunities, the Prius and Prius PHV become progressively more economic.
Toyota engineers were among those early critics of the Volt setup, pointing out that it's more efficient to turn the chemical energy in gasoline directly into mechanical energy rather than turning chemical energy into mechanical energy, and then into electrical energy.
So, IIRC most Volts are getting 30-40mpg highway after battery depletion.
First, start with the fact that the Volt is a larger vehicle than the Yaris or Corolla. From the article:

"The unit isn't powerful--10 kW equates to about 13 horsepower--but just two of them produce enough charge to let a Yaris or Corolla-sized electric vehicle cruise at 75 mph on the highway."

Well, we can assume that because they're smaller cars, putting the Volt system in a Yaris or Corolla would yield better highway mpg. That isn't necessarily the case, and we've seen 40mpg-highway midsize sedans, mainly due to better aerodynamics. Nonetheless, let's give a Yaris or Corolla with a Volt system inside of it about 35-45 mpg highway, using a standard 2- or 3-cylinder engine that's optimized for mechanical output instead of electricity production.

Let's also assume that this engine is 40% efficient. It says you'd need 2 of them working at the rated 10kw, or 20 kw, to move a Corolla / Yaris at 75 mph.
20 kw for 1 hour, or 20 kwh, would require 50 kwh of gasoline.
One gallon of gasoline has 33.7 kwh, so you'd burn 1.5 gallons in order to provide the 20 kw necessary to push a Yaris / Corolla at 75 mph for 1 hour.

In other words, 50 mpg, or equal to a Prius. (or better? how many of you gen III's get 50mpg @ 75 mph? I know my gen II can't!)

So, with this engine as a range-extender in a Volt/series type system, there is NO 'highway penalty'. This is taking maximum advantage of an ICE design that runs in a very narrow "RPM" (though nothing's rotating!) and is only designed to produce electricity (it'd never work for direct drive through a mechanical transmission).

The fact that Toyota is developing this tech leads me to believe that we'll be seeing more primarily-serial hybrids in the near future, especially those with plugs.....IMHO, the design will combine the best qualities of both PiP and Volt.

 

This seems like a fair analysis, at least based on the information given. If the engine(s) are small, light, and cheap; and emissions are not a problem, Toyota will have a winner.

 

It ("free piston") is ACTUALLY a very old concept...Ford experimented with similar back in 1957, and EPA has a 2001 paper on their similar work: http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/30535bf.pdf