alt.energy.renewable

From: "Anthony Matonak"
Subject: Re: Business Week: Air-Powered Green Car in U.S. in 2010
Date: Saturday, March 15, 2008 4:40 PM

Vaughn Simon wrote:
>> Both methods involve expanding the air without extracting useful work from
>> it
>> in the process, and both methods will decrease the temperature of the air,
>> unless space-robbing heat exchangers are provided. In other words, both
>> methods
>> introduce significant losses to a system that already must have large losses.

>What's wrong with space-robbing heat exchangers? They could make them
>pretty big without adding a huge amount of weight and the electric fans
>they would require could be run off a relatively small battery. The
>thing requires massive heat exchangers for the intercoolers anyhow.

Well you pretty well covered the disadvantages. As you imply, this would
only be one of several heat exchangers necessary to any passably-efficient high
pressure air engine. You could make the heat exchangers smaller and then burn
up lots of energy to blow a large mass of air through them, or make them larger
and perhaps get by with much less energy waste.

One thing you got wrong was the weight. Remember, the heat exchanger must be
made to take high pressure air; so it would need thick walls.



Vaughn