Stephen A. Lawrence <[email protected]> wrote:
> In fact, the *goal* of the heat exchanger is to conduct heat from the > primary to the secondary pipes, as rapidly and completely as possible. Sure, I get that. > Consequently, the primary inlet and the secondary outlet are placed in > extremely intimate contact as soon as they enter the heat exchanger. (When > most normal people imagine a heat exchanger they think of a device where > the two flows are going in the same direction, but that's actually a far > less effective design than the counterflow scheme which is used in > practice.) > I saw that! Isn't that nifty? Counter-intuitive at first but it makes sense. > The issue is that, assuming the exchange of heat isn't perfect . . . Well of course it isn't. Nothing is. but as I recall, the specs for this one showed much higher efficiency than some online guide heat exchangers I found, which was probably way out of date. This is remarkably efficient. > , the secondary outlet may actually have been substantially cooler than > the primary inlet, in which case heat traveling through the surfaces of the > pipes (and, possibly, other parasitic paths) may have caused the > thermocouple to read some temperature between the value for the secondary > effluent and the primary inlet, Sure, that may be a problem. But parasitic paths are reduced to a minimum in a good design. That's my point. Any parasitic path reduces efficiency. I think you should take a close look at Houkes, if you have not done so already. If you find a problem, tell us what is wrong with it. - Jed
