On Mon, Jul 18, 2011 at 8:06 PM, Mark Iverson <[email protected]> wrote:
> > > In all the talk about the start up slope and thermal mass, one can almost > forget the metals. Here > are the specific heats for most of the materials that make up the majority > of the e-Cat: > - Hydrogen (gas) 14.30 J/g*K > - Water (liquid) 4.18 J/g*K > - Stainless 0.5 J/g*K > - Nickel 0.46 J/g*K > - Copper 0.39 J/g*K > - Lead 0.13 J/g*K > > The only thing that has any real heat capacity is the water and hydrogen... > But the water is flowing. It is always replaced at the same temperature, so it is not involved in the warm up. It's the thermal mass of the ecat that causes it to take time to warm up at the beginning, and to cool off at the end. The hydrogen may have a high heat capacity, but it makes little contribution because its mass is so small. > > In addition, the rubber hose has about HALF the heat capacity of water, so > it can absorb a > considerable amount of heat before it changes temperature... > That's not how heat capacity works. Any change in heat causes a change in temperature; it's only a matter of how much. But there is a way to absorb heat without changing temperature: when the phase changes. That's why the temperature is not varying by even a small amount. Any fluctuation in the power is absorbed by variation in the steam wetness without any change in the temperature. That's why the flat temperature is such good evidence that the steam is wet.
