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de Jong Review of Steam and Flow Fundamentals
Appendix 6 to New Energy Times Report #3
By Jan de Jong
I have read New Energy Times Editor Steven B. Krivit's recent Report #2 about Andrea Rossi, and I more and more get the feeling that Rossi is not careful enough with the steam. In itself, this is not a disaster as long as he does not use the steam balance to derive the energy efficiency of the LENR mechanism. But because Rossi uses the steam claims as the basis for the energy production of the nickel-hydrogen reactor, I fear that he is making an error that may affect the conclusions of his findings.
I am a heat transfer specialist, and as a designer of hundreds of heat exchangers, I have dealt with all type of heat transfer problems for many years with Shell Petroleum. I was, therefore, surprised to see how Rossi was having difficulty with the heat balance of the boiling steam and incorrectly simplified the heat balance to mass flow multiplied with the steam latent heat. In the case of a pumped heat exchanger, this likely will result in an unacceptable overestimation of the thermal duty.
Krivit hinted that it is very important to take into account the quality of the steam. Because the heat of vaporization is much larger than the specific heat, Rossi can make a very large error.
In refineries and industrial installations, steam kettles are used very often. Heat is supplied to the kettle bath through submerged tubes, and boiler feedwater is fed to the liquid bath. The steam vapor leaves the kettle through the outlet nozzle. The boiler feedwater flow to the kettle is controlled through a level measuring instrument. So you must take care that only the tube bundle is submerged. So long as there is a large separation zone above the liquid bath and a sufficiently large outlet nozzle to reduce entrainment of water droplets, you will find less than some 0.2 percentage (in weight) of water in the steam emerging from the kettle.
But the reactor wall as Rossi is using it is not a kettle but a pumped heat exchanger with an allegedly fixed mass-flow rate of water. He claims to pump in 7 liters per hour, and, due to the electrical heat supplied plus the LENR reaction, steam is formed.
As Rossi pumps in a fixed mass flow of water, only part of the water likely will vaporize, and that part of the water will leave as liquid water. If Rossi concludes in such a situation that the heat duty equals the mass flow multiplied with the latent heat of water, he likely will end up with a large error.
As Krivit may have known when he filmed Rossi's demonstration, the density of the water is much larger, so an observer will see only drips of water at the outlet of the hose. This water is not significantly attributable to condensed steam because of heat loss in the hose to the environment; that heat loss is very minor. This is water that comes out of the reactor and was never vapor in the first place.
To make a more realistic measurement, Rossi should have taken a small knock-out drum to separate the liquid water close to the reactor (insulate the knock-out drum and piping), and then he should condense the steam from the knock-out drum in a condenser so that he can measure both vapor and liquid flows separately. I do not understand why his test facility is not built that way. Alternatively, Rossi could have designed the reactor system as a kettle (see above) whereby the liquid level is controlled by a level controller.
For completeness’ sake, if Rossi would pump in too little water so that all water evaporates, the steam superheats and possibly the nickel wall will overheat. I do not know what will happen then to the reactor and whether it would lead to larger heat production or an explosion. But let us assume that Rossi prefers a water flow that is large enough so that there is liquid flow left.
Now the question is whether we could conclude something of value in the test that was performed on June 14. As seen in Krivit's video, Rossi took out the hose from a hole in the wall, and we could see some steam slowly coming out of the hose. I estimate the inner diameter of the hose at about 13 mm.
When we assume, as Rossi claimed, that all the water (7 kg/hr) becomes steam, then the steam velocity at the outlet of the hose should have been about 25 m/s. From what the film showed, however, the velocity was instead about 2 to 3 m/s, ten times less. And water was dripping from the hose.
When we ignore the water volume and the sensible heat that goes into the water, heating it to 100 degrees C without boiling (latent heat is much larger than the specific heat and the density of water is 2,000 times larger than the steam density), then we can simply calculate the heating duty which corresponds with the estimated 2-3 m/s steam in the outlet of the hose. The remainder of the water flow from the pump is then simply dripping from the hose. Working out a heating duty, we find it to be on the order of about 600 W, which all of a sudden comes very close to the electricity that goes into the heating element in Rossi's device.
Like everybody, I would have preferred to be convinced by this LENR device because this is really what mankind desperately needs. But with the oversimplification of the steam measuring (perhaps we can say no measurement at all), I feel strong doubts. Let us hope that Rossi did not heat his building with a complex electrical heater.
There is one question that remains: I understood that Giuseppe Levi, on behalf of Rossi, also performed a test whereby he did not produce steam at all, but by increasing the water flow, the outlet temperature of the water was well below 100 degrees C. In that case, there will be a much more accurate energy measurement.
Further, I would like to thank Krivit for all his hard work. In my view, he was not rude to Rossi or Levi, but he was critical. And that is what any specialist and scientist should be.
Brief Biography of Jan de Jong (Netherlands)
Engineer Jan de Jong has a master’s degree in mechanical engineering from the University of Delft, Netherlands. His thesis was a literature study on gas movement in diesel engines with direct injection. His master's study was on computational fluid dynamics modeling of gas movement in diesel direct injection engines during suction and compression stroke, taking account of swirl and geometry. He worked for 30 years with Shell Petroleum in various functions, including Shell´s Research Laboratory, Pernis refinery and Shell Global Solutions. He was a senior heat transfer specialist, senior gasification burner specialist, and senior process engineer. He now works in his own consultancy and engineering firm and performs design and thermal modeling, specializing in thermal engineering, heat exchangers (TEMA), fluid flow, burners and gasification.
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