>From: Robert Lynn <[email protected]> >Sent: Tue, Oct 18, 2011 11:08 am
>Thanks for the work David, a few questions: >-It appears you are assuming the accuracy of the data from the secondary >thermocouple (excepting a simple 0.8°C offset) and that there was no water in >the reactor at the start (11:00) when the pump was turned on. Do you think it >unlikely that the >secondary outlet thermocouple error changed with the rate >of steam flow through the primary given it's poor placement? I am confident that there is not water in the ECAT at the beginning as it was weighed before and after emptied of water. These numbers were in agreement. You are correct in assuming that there may be an error in the thermocouple placement. I made the simulation based upon the readings being accurate as that is the only measured values. It would be ideal if someone could obtain one of the same type of exchangers and make tests to verify the actual facts. My personal opinion is that the water flow rate in the secondary dominates the effect. This flow runs throughout the tubing for a significant distance where it takes most of the wicking heat from the input port away. I am attempting some thought experiments in an effort to understand the temperature distribution across the exchanger. >-Have you used any of the videos to estimate primary water flow rate, or check >for variation? The noisy pump delivers maximum of 2ml/stroke, and I believe >this drops at higher pressure (pump rated for max 1.5bar). Yes, I used both of the test videos. The October as well as September videos reveal the pump rate settings. It is quite clear in the September video that the rate is 50 pulses per minute. Others and myself have listened to the October video and have found it to be approximately 40 pulses per minute. The pump is rated at a maximum mass per pulse of 2 grams(weight) and it was set at that position according to a picture taken by Mats. I picked several values to plot and you can change the simulation rate to any you wish to test. I do have several questions concerning the September test flow rate. The pulses per minute and mass rate settings do not seem to match the fine measurements Mats conducted during his trip as well as I would like. We are trying to reconcile this data. I will include the variation of input flow with internal pressure if that data becomes available. >-How do you explain the temperature variation in the reactor once it gets >above 100°C, and in particular the fact that highest temp doesn't correlate >with greatest power? Do you think the steam is being superheated? Normally >when a fluid's temp is >raised above ambient pressure it will rapidly boils >off to drop it's temperature to ambient again, do you think there was some >sort of variable flow restriction in the outlet from the reactor to prevent >this? I think that a check valve is in the output coupler on the top of the ECAT. There is a spring and ball (or equivalent) with a matching shoulder for a seal. In my opinion this type of device would be required to prevent vapor reversing into a dead or leaking unit when many ECATS are placed in parallel as in the 1 Megawatt power unit. The current valve design must be based upon having 3 ECAT cores internal and active so it is not functioning in its idea mode with just 1 core as in the test. The spring could easily push the ball against the shoulder to achieve any desired cut off pressure. Mats found that the path was restricted to his attempt to blow air through the output connector, supporting this assumption. I am currently pursuing the idea that the check valve may be causing some of the strange effects measured during the test run. A minor change in the pressure caused by water within the plumbing might cause this valve to restrict flow or open further leading to a large change in vapor output. And, if hysterisis is present in the valve opening, a lot of the measurements would make sense. This is just a theory that I am considering, and not proven. You mention that the highest temperature point within the ECAT vapor does not match the highest power output per the secondary flow measurements. I am researching the idea that valve restrictions lead to less vapor exiting the ECAT. In this state I would assume that most of the new energy is thus being stored within the ECAT and should result in internal temperature rise. This is part of the same theory. I would appreciate you taking time to consider some of the concepts I have just suggested. We may be able to construct a better theory as more people look for major holes and make patches. Dave
