Lewan told me that the thermocouples from the handheld meter were taped to the outside of the metal pipe, and then very well insulated.
People may complain, but actually that is a fine way to do it, in my experience. In the video, Rossi unwrapped the pipe and showed where the thermocouples were attached. That is at time 3:28 in the video. As I wrote here: "The pipe itself averages out the temperature nicely. Many researchers such as Miles and Takahashi use probes on the outside of metal shells, and calibrations show that it works well." The position of the outlet thermocouple bothers me a little. Regarding this, Mark Iverson wrote: It is clear in Lewan’s video that the steam input (primary circuit) is on the SAME end of the heat exchanger as the secondary circuit OUTPUT… so the Tout thermocouple is within 2 to 3 inches (perhaps less) of the steam (120+C degrees) input! For maximum heat transfer you want the maximum delta T, so I would think that you want the steam input being on the same end as the cooling water input???" I suppose they read the heat exchanger manual and it said that's how to set it up. The proximity of the 120 deg C steam to the outlet thermocouple is a concern, as I said. I think there is so much more cooling water coming through this pipe than steam coming into the pipe next to it that this pipe will be the same temperature as the cooling water. The thermal mass of the cooling water is much greater than that of the steam, which is why the final temperature of the two fluids ends up closer to the water than the steam (around 5 deg C higher than tap water). I doubt this is a problem, but it would have been much better to check a sample of cooling water, to be sure this is not a problem. I urged people do to that, before the test, as I reported here. Unfortunately, they could not check that because the damned hose attached to the outlet was 20 m long, leading outside the building. I was chagrined when I heard that. Upset. Cursing and fuming. It is another reason this test was lousy, when it could easily have been good. Like the other problems, this could easily be fixed. Here is how I would do it: Assume they need to dump the water 20 m away. I can't imagine why, since 10 L/min is not that much water, and you can dump it down a sink, but anyway let's assume it has to go 20 m. A single hose is a stupid way to do this because it prevents you from taking samples near the outlet. This is big problem. It is also a bad idea because the long hose can get tangled or crimped, changing the flow rate. You can see someone put a doormat on top of the hose, for crying out loud. Since they did not record the flow rate on computer, they might not notice the flow rate changed. Fortunately, Lewan noted the total cumulative volume of water for the test: 4,554 L, which comes to 178 g/s, close to the instantaneous readings, so I guess that was not a problem. The simple solution is to cut the hose off at 1 m, and let it flow into a large bucket. In the bucket you put a utility pump and garden hose. These pumps cost $80 and they run fine even when the water all drains out and the pump runs dry. See: http://www.lowes.com/pd_309016-15649-PPU6_0__?productId=3089853 Rossi just does not want to take the trouble to do this right. - Jed
