Hello /sci/ I have this engineering equestion, I'll try

File: images2.jpg (27KB, 640x480px) Image search: [Google]

27KB, 640x480px

Hello /sci/
I have this engineering equestion, I'll try to phrase it as clearly as possible.

Let's say I have a gas turbine Generator, and I want to make it kind of like a Combined Cycle one.

I have a regular turbine, pic mostly related. And at the exhaust nozzle I put a reaaaaally long tube that has a conic shape, so it's diameter get's smaller as the distance increases. Now, i have a bigger tube outside of it. Concentric to the first one, and has the same pattern of change in diameter.
The inner tube is for hot combustion gases exhaust and the one outside is for cool intake air.

If the tubes are long enough(and made with a good heat exchange material) let's porpose that the heat exchabge between the intake and exhaust is 100% by the time the tube ends.

So the combustion gases temperature at the end of the looong exhaust tube is the same as the temperature of the instake air.

Assuming this and that the turbine and system are perfectly insulated, chemical combustion 100%,blah blah etc. Is it safe to say that the ONLY loss in efficiency will come from friction?

This way all the chemical energy passes "directly" to the shaft, isn't that right?

>TL;DR:
OP wants to make a super efficient CC gas turbine with a stupidly long heat exchanger so that the only loss is due to fruction. Will it work?