Bob Cook <[email protected]> wrote:
> I think you assume that the reaction did not change the differential > pressure that the pump sees as the reaction occurs. (In other words the > "baseline" energy is a constant during the reaction.) > I did not "assume" that. I observed that during the 18 hour calibration. There is a huge difference between assuming X and running a test to prove X. > What I have suggested is that the differential pressure across the pump > should be measured, and it should be constant, if your assumption is valid. > The 18-hour test measures this and any other factor that might change the amount of work done by the pump. It covers all bases. This proves that any hypothesis you can come up with about how or why the pump output might have changed must be wrong. > If it is not, the pump energy input would have changed during the reaction. > It did not change measurably. The kinds of effects you are describing would be at the milliwatt level I believe. We could not detect with this system. Local two phase flow in a water stream will change the pressure drop in > that region where two phase flow occurs. Changes in the water viscosity > (and resulting pressure drop) with the small changes in temperature of the > test should be negligible compared to potential two phase flow > conditions--i.e., steam bubbles plus liquid water. > Steam bubbles? Have you looked at the data? The water temperature changes from 23.0°C to 25.5°C. There will be no steam at these temperatures. There is not the slightest chance such a small temperature change could have a measurable effect on the amount of work done by the pump. (Measurable with this system I mean. Perhaps a micro-calorimeter could detect it..) The water temperature did rise 0.6°C from the effect of the pump. I am not saying the pump had no measurable effect at all. I'm saying that the work done by the pump did not vary enough to be measured by the system. - Jed
