Yes, that is what I meant to propose, but when you have that additional heat exchanger, why would you use steam rather than air (or some other fluid like helium or argon) in the low-pressure pipes?
An expensive gas would present the problem of leakage. If that could be cheaply addressed, great, otherwise go with something where making up small leaks is not expensive. That probably means steam or air.
I think steam would have better heat transfer properties than air, maybe?
I do wonder how much we should worry about oxidation of the pipes. Stainless is certainly fine at 600 C in an oxidizing atmosphere, but what about cheaper steel?
I think steam would have better heat transfer properties than air, maybe?
I do wonder how much we should worry about oxidation of the pipes. Stainless is certainly fine at 600 C in an oxidizing atmosphere, but what about cheaper steel?