Jones Beene wrote:
JR:The power input related to the proper operation cannot be measured with flow calorimetry, and even if it could, it would be many orders of magnitude too small to be detected by these methods.
That is supposed to say the PUMPING operation cannot be measured . . .
No one is suggesting that you measure this input by via flow calorimetry. Aren't you conflating two issues?
No. The only calorimetry performed in this experiment is for the cell, between the inlet and outlet sensors. No other energy needs to be measured or considered. What happens outside the cell does not count.
There is a microscopic contribution by the pump between the inlet and outlet sensors, but it could not be detected with any sort of macroscopic calorimetry. It would require micro-calorimetry, being many orders of magnitude smaller than the heat from the control resistance heaters or the reaction.
You put a kill-a-watt meter on the pump, but you MUST include its power as P-in, just as you must include the electrical power to the resistive heaters as P-in. You add the two along with any other power input which is necessary.
No, the Kill-a-watt goes between the control electronics and the wall socket. There is no need to measure the pump input because it cannot transfer to the system between the inlet and outlet temperature sensors. The water does not slow down or stop between those points, so none of the pump energy converts to heat. The heat added to the water by the pump mechanical action is added before the inlet sensor, so it does not register.
The is no question but that ALL required input power MUST be included as P-in
No, that is incorrect. Only energy which enters the system after the cooling water passes P-in can be measured, and that is the only energy that need to be measured. The pump is outside that, so it is irrelevant.
- Jed
