1700W. It does not appear to show that boiling was taking place
Note that the test duration at that power was just 10 minutes. What would happen after an hour or a day at high power?
MFMP: Next replication - GlowStick 5.4 aka GlowShell
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This chart http://www.flourmilling.co.uk/water.html shows that a 6mm steel tube at 6Bar passes 0.028L/sec. Which is 1.44L/minute. Probably much more than they need- but those tubes would never hold 6Bar. At 1Bar it is 0.6L minute - probably doable and just sufficient to prevent boiling. But only just.
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it does not appear that in that specific case very high water temperatures would have been eventually reached.
Looks like about 0.1 °C / minute. So it would reach boiling in about 10 hours.
More water or a radiator seems like a good idea. Let's keep discussing this - it may be workable. -
Flow calorimetry is inherently better than open heat emitters tested for temperature, because it is difficult to control or even know all the effects that change effective thermal resistance, AND the thermal resistance is not a priori known.
You still use cal runs for the flow calorimetry to check everything is wrong - but you are one step ahead because you know what the cal result is supposed to be.
It is hands down a better method if practicable.
There are still errors: water flow mismeasurement, boiling, TC mis-siting. All easily avoided if you are not Rossi.
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gameover wrote:
Looks like about 0.1 °C / minute. So it would reach boiling in about 10 hours.
More water or a radiator seems like a good idea. Let's keep discussing this - it may be workable.
The measurement time was too short to notice that the temperature line would turn as equilibrium was reached. The increase in temperature showed that equiilibrium wasn't attained.for more precision, ideally, the temperature rise would be maximized, but kept short of boiling. Water flow would be increased only if it started to boil. The lack of equilibrium probably is due to the calorimeter itself heating up.
A calorimeter like this, properly done, can show high heat definitively. All of this depends on the independence and probity of those doing the work. For maximum value of its work, MFMP will continue to strive for scientific excellence, including all the necessary and rigorous self-doubt.
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Quote from Roger Barker: “Hi, I am no expert on calorimetry but Mary Yugo is. She knows all about calorimetry. We've used them often in our fact finding sessions.
Mary, can you kindly share your thoughts on using calorimetry for MFMP.”
As you may…
Hi, yes! This is definitely one of the calorimeters Mary and the crew at ECN have familiarity with. They've described its use in some detail. You will have to trawl through ECN to find the relevant sessions but I believe Popeye (Joshua Cude) and Mary had numerous sessions with this calorimeter. I was an observer in most cases and did not participate.
Mary, are you still in contact with Josh? If so can you kindly extend him an invite so we can get his input on this matter. Thanks.
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Flow calorimetry is inherently better than open heat emitters tested for temperature, because it is difficult to control or even know all the effects that change effective thermal resistance, AND the thermal resistance is not a priori known.
You still use cal runs for the flow calorimetry to check everything is wrong - but you are one step ahead because you know what the cal result is supposed to be.
It is hands down a better method if practicable.
There are still errors: water flow mismeasurement, boiling, TC mis-siting. All easily avoided if you are not Rossi.
Flow calorimetry is much more difficult than one might imagine. I don't recommend it for these types of experiments. Conduction calorimetry is a lot simpler and you don't have to deal with leaks, flow rates, and numerous problems that arise in flow calorimetry. MFC can be done well. Brian Albiston did it well. JPB did mass flow. Jeff Morriss did air flow. Guess what? No excess heat.
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Recirculating water at a steadily increasing temperature might not be the best idea, since the heat losses from all parts of the calorimeter will increase if the insulation is as 'casual' as the photograph suggests it might be. With a calibrated dosimetric pump it might be possible (and preferable) to draw fresh water at a known and stable temperature and volume from a reservoir, pass it through the heat exchanger, measure its temperature again at the exit point and then dump it.
What do you think?
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Recirculating water at a steadily increasing temperature might not be the best idea, since the heat losses from all parts of the calorimeter will increase if the insulation is as 'casual' as the photograph suggests it might be.
I am not sure what photo you refer to but anyway . . . I suggested phase change calorimetry, boiling off the water. I suggested a steam trap that would return hot water to the reservoir. To do this you need a well-insulated reservoir. Otherwise, as you say, the heat losses from the reservoir will increase significantly, making the calorimetry complicated.You have to calibrate this system carefully. You have to test it with a cold reservoir and a hot one. It is complicated. Phase change calorimetry is complicated and I do not recommend it. Sometimes it is the only practical method.
The other phase change calorimeter is the ice calorimeter, where the mass of ice that melts indicates the heat. This is one of the first kinds of calorimeter ever devised, in the 1770s and 80s. I have seen some cold fusion results from ice calorimeters. Most were bad, in my opinion. I do not recommend this instrument.
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This one Jed.
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Overall I think it would be best to not complicate things excessively for this sort of calorimetry.
I agree. And in the interests of less complications I shouldn't imagine that losing a few hundred litres of water would be a problem. Especially as they could be recycled via the rainwater-butt. It wouldn't be in most of (the soggy end of) Europe. But maybe magicsound knows.
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I would like to point out that calorimeters are difficult to setup and use to obtain credible results is that they are intended to make absolute measurements. Sure, there are good procedures for calibration, and they must be done before and after the experiment. There so many opportunities for it to be screwed up, that it is a wonderful target for equivocation after the experiment has ended. Compare this to the Glowstick type of experiment. This experiment will be calibrated too. But, small changes to the environment generally affect both the active side and the control and the delta-T is still valid. In the calorimeter, you have a large experimental heat output and a large calibrated heat output and you are subtracting these two heats to find the excess heat. This is a case of error possibility from the difference in two large numbers. On the other hand, when the simultaneous control is run, the delta-T is fairly accurate by comparison and the heat calculated from the delta-T is more credible than running a separate active and null experiment and subtracting the heats. In fact, you can configure two thermocouple junctions in series such that they only report the difference in temperature between the active and null side with separate thermocouples measuring the absolute temperatures.
To prevent CCS type of problems, calorimeters are first built with great precision and stability, and are situated in a constant temperature box. Everything is controlled to the Nth degree and the measurement precision will need to be 10x better than the desired sigma. Proper calibration requires measurement checks with NIST standards. For example, you can measure V and I each with high precision, but unless V and I measurements are calibrated to NIST standards, multiplying V and I will not give the correct power. Calibration and modeling of a calorimeter is a big undertaking to achieve credible results. And, in this field, even credible calorimeter measurements will be assailed.
In my opinion, the method of active + control experiment can reliably measure/demonstrate excess heat better than calorimetry. A well constructed, well calibrated, and expertly operated calorimeter will return a good measure of the excess heat from a single experiment, but the investment to achieve this is an order of magnitude more than that to setup and run an experiment having a simultaneous control experiment.
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Just a quick note: if such calorimeter ran for a week at a flow rate of 1 liter/minute it would use about 10000 liters of fresh water.
Quite close. However, considering this a problem ignores two things:1. The value of the work. http://www.circleofblue.org/wp…4/WaterPricing2015map.pdf
The cost of 10,000 liters of water would be, in San Francisco, one of the most expensive cities in the U.S. about $54. That includes sewer charges, which can exceed the actual water cost substantially. $54 is probably well in excess of the value of the work, and taking steps to ameliorate this cost might not be worth the effort.
2. The assumption above is that public water is metered through a valve, so no pump is needed. This water then passes through the system, is heated, and then runs into the drain. If it is very hot, that can be itself illegal. There is a temperature limit. It might be possible to observe it, but this requires the temperature rise be kept down, thus increasing the volume of water needed.
An option would be to have a large tank ... a cheap and easy one is a simple portable swimming pool. This water would be pumped and metered into a small tank where temperature is even -- perhaps it's stirred -- it can be a bit warm -- and then it's used for temperature rise in the calorimeter. Some of the water will evaporate (which would cool it more efficiently) but there would be far less water usage. I once used a small swimming pool as an ad hoc water storage tank for a small community of about 200 I designed and built on the cheap, for a week in the Arizona desert. Maybe I paid $20 for it, maybe less, new. Ah, that was fun!
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Abd, why do I get the feeling this story involved lots of LSD?
This is definitely one of the calorimeters Mary and the crw at ECN have familiarity with.
Roger, I too am interested too know what inputs Yugo has, regarding the use of these types of calorimeter. -
Abd, why do I get the feeling this story involved lots of LSD?
Oh, that's easy. Because you are an idiot, who believes that his imaginations have some substance.
It involved no drugs, absolutely nothing illegal. This was something over forty years ago, so okay, there were some "hippies" there, but I saw no drug use and it would have been highly disapproved. For me, the most significant thing was building that camp on a shoestring, designing structures that worked, providing what over 200 people needed for a week -- and then cleaning it up and recycling much of it.
What's relevant here is improvisation, finding simple ways to fulfill necessary functions.
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OK, just a few quaaludes then.
you are an idiot
What a hurtful and totally unnecessary descent into personal abuse. Perhaps if there was a some type of system whereby you could avoid having to see my comments, I could avoid suffering the same unpleasantness in the future. -
Abd, why do I get the feeling this story involved lots of LSD?
Quote from Roger Barker: “This is definitely one of the calorimeters Mary and the crw at ECN have familiarity with.”
Roger, I too am interested too know what inputs Yugo has, regarding…If you trawl ECN you'll find many posts of her experiences with this calorimeter. All quite descrpitive! The design is ideal, length and width can be modified depending on the session.
