On 02/08/2011 03:52 PM, Terry Blanton wrote: > On Tue, Feb 8, 2011 at 3:29 PM, Stephen A. Lawrence <[email protected]> wrote: > > >> In an open boiler with a submerged heating element, the steam won't rise >> above 100 C, because its temperature is buffered by the liquid water with >> which it's in contact. In a pipeline, once the water has boiled away to >> steam, the steam is no longer in intimate contact with liquid water, but >> it's still in contact with the heating element, and there's nothing to keep >> it from getting hotter as it moves along the tube. >> > You are making assumptions about the geometry of the device. How do > you know there is no liquid water reservoir? >
No, I am not making assumptions about its geometry, beyond one very simple assumption: The total volume of water which flowed through the device was significantly larger than the internal water storage volume of the device. With that assumption, we can ignore what goes on inside the device. If that assumption is false, then the whole test is worthless anyway because there are all kinds of games you can play if you've got substantial excess volume. I am also assuming that essentially all the heat produced was carried off by the steam. If these two assumptions are true, then we can completely ignore the internal geometry of the device. It's easiest to think of it as a simple tube, but the internal shape of the water jacket really doesn't matter. What matters is the amount of heat which must be carried off -- unless it EXACTLY matches the heat needed to warm the water to 100 C and then vaporize it, you won't get pure dry steam at very close to 100 C coming out. And the amount of heat needed for that is set by the *pump*, with no feedback from the reactor. On the other hand, if the device was getting scorching hot in spots and radiating away a lot of its heat, then we can imagine a configuration in which the output temperature could be held fixed near 100C even with varying flow rates. But it seems to me that's stretching things a bit -- among other things it pushes us to the conclusion that it's really producing substantially more than the claimed 12 kW, but its water jacket is so badly designed that the heat's escaping instead of being measured. > T > > >
