Posts by Robert Horst

    Your graph is interesting.


    IMO, the cause of Delta Tair variations is the noise due to the turbulent rising of the cooling air inside the acrylic box. This air flows over areas of the reactor surface which are at different temperatures, so its vorticity can cause the air to heat not uniformly. The Delta Tsurf is roughly proportional to the Tmax of the reactor body whose heating and cooling trends are substantially delayed by the large mass of the reactor metal. You can see in your first graph that amplitude increases at the power-on and decreases at the power-off following trends very similar to the heating and cooling phases of the reactor.

    You may be right the the cause is related to the turbulent air, but realize that the data points in the spreadsheet are 25 seconds apart. It is hard to imagine a vortex that lasts 25 seconds or longer and makes the average 2 deg C hotter or colder than the previous 25 sec.


    Maybe the problem is the way this spreadsheet was derived from the raw HP data logger measurements. The logger probably sampled much more frequently than once per 25 seconds. I was assuming that each 25 second spreadsheet row is an average of the last 25 seconds, but maybe the spreadsheet just takes one raw measurements from each 25 second period. That may show the large variation we see, while averaging them (integrating over the entire period) would smooth everything out.

    No, I do not think plasma heating or any other heater-related noise could lead to the output temperature variations. If you look at my first graph above (just edited to fix the horizontal scale), the large output temperature variations last for more than 10,000 seconds (> 2.7 hours) after the heater is turned off.

    On a slightly different subject, I have been wondering why there is large variation in the output temperatures while the heater is on, but not when it is off. Here is a graph I produced from the Mizono spreadsheet:

    The temperature varies +- 2 degC while the heater is on, but then less than +- 0.1 degC after it has cooled.


    To look for periodicity in the variation, I took an FFT of the data, here it is plotted in the frequency domain on a log scale, and in the time domain on a linear scale. The input is the delta between measurements, which is like using AC coupling to a scope or putting the signal through a high pass filter.


    There is one peak at .015 Hz (66 seconds), but it is not much higher than the other frequencies. The distribution is pretty flat, like white noise.

    • It seems unlikely to be instrumentation inaccuracies, or they would affect the later measurements with power off.
    • It is not noise coupled from the heater or its power source, or it would drop abruptly when the heater is powered off.
    • I looked at deltaTemp for the input (ambient) air, and it has about the same low variation as the cool part of the experiment. That cannot explain the large heater-on deltas.
    • If the peaks were from excess heat events, it seems like there should be no low peaks. It is hard to imagine excess cool events.

    I am at a loss to think of a cause for the output temperature variations.

    Experiments that use an internal heater have a different equivalent thermal circuit than the one I posted earlier. This circuit would apply to R20 as well as the earlier experiments if they also use an internal plasma heater.

    lenr-forum.com/attachment/9719/

    The diode is here because I assume that when the heater is turned off, it does not contribute to cooling of the mesh. This also uses better values for the heat capacity as suggested by THH and RB. The reactor is 20.3 kg * 500 j/kgC and the mesh is .3 kg * 450 j/kgC.


    For the reactor thermal resistance, I found a reference that says forced air cooling has a convection coefficient, h, between 30 and 600 W/m2C. R = 1/hA. The reactor is 114 mm dia x 600 mm L for an area of about 0.21 m2. That makes Rra = 0.1 to 6.4 degC/W. That is a huge range depending on the blower and surface it is blowing over. I used a value of 1, but it would need to be measured. All thermal resistances are not much better than pure guesses.


    Using the values shown above, here is what the reactor temperature (delta T from ambient) would look like:


    And this shows both the reactor and the mesh temperatures.

    It is hard to draw many conclusions based on the long time constant at the tail of the experiment. The amplitude of the tail is less that 1 degree which is much less than the errors in the rising edge measurements. That means that there might not even be any tail at all. You can't conclude anything from measurements smaller than the noise.


    If your calculation of the heat capacity and thermal resistance of the mesh is correct, you are right that it will not have much effect on the tail. But I am not sure if we can get accurate values for either the heat capacity or the thermal resistance.


    I used "mesh" to mean everything inside the vacuum chamber. There may be other thermal masses, like an internal heater used for later experiments. That would have a big effect on the heat capacity.


    The thermal resistance to the mesh (plus whatever) could be extremely high. Part is in contact with the reactor wall, but part is not. Try heating one end of a screen and see how much heat you detect a few inches away. The thin Ni wire in the screen is a lousy thermal conductor. Also, if there was something else like an unused heater inside, that could be very well insulated by the vacuum.


    My simulation was not intended to try to arrive at any specific numerical results. I posted it more as a technique that could be used by those doing the experiments. They could measure the values of the six parameters fairly easily and come up with a simulation to show what should happen without excess heat, then show what actually happens and analyze the differences.

    Great work Robert

    Four questions if I may be so bold as to ask

    1. Does the SPICE sim give a regression value saying how good the fit is on the heating phase , and on the cooling phase?


    No. SPICE does not do that directly. There are ways of varying parameters or adding comparisons to algorithmicly generated waveforms, but that would take quite a bit of work.

    2. Is it possible to include the thermal inertia of the insulated Perspex walls.. maybe the mass is 11000 g or more? Cw= 1.5


    Yes, more elements could be added easily if enough information could be gleaned from the experiment.

    3. Can the voltage on the vertical axis be made to correspond to energy content in Joules?


    Yes, that could be done. Not sure how much time I have to continue this though.

    4. What is the expected maximum temperature of the Nickel?


    The Nickel should eventually reach the same temperature as the housing if the circuit is generally right. There is a thermal path (Rrm) to heat it from the housing, and no thermal path to cool the mesh (no resistor to ground). But that assumes that the heater stays on long enough. If the mesh heat capacity is large (large Cm) and the vacuum does a good job of insulating the mesh (large Rrm). The time constant to reach equilibrium is very large.

    There is more than one time constant in the Mizono experiment and the interactions between them are not easily solved without simulation tools. The same differential equations for heat flow are the ones used in EE for RC circuits. I have created a simulation based on this and used a SPICE simulation to create the waveforms. This is the circuit, where:

    Cr = Heat capacity of the reactor

    Cm = Heat capacity of the mesh

    Rhr = Thermal resistance from heater to reactor

    Rh = Thermal resistance of the heating element

    Rra = Thermal R from reactor to ambient (fan speed dependent)

    Rrm - Thermal R from reactor to mesh

    Voltage is analogous to temperature.

    The simulations go from 0 - 70 ms, to correspond to 0-70 Ks in the experiment.


    Waveforms below alternate between those from the Mizono spreadsheet and SPICE sim of this circuit. I am using 4 columns from the Mizono spreadsheet - Time, Air In Temp (for ambient), Air Out Temp, and Heater Temp. I used Reactor temp = Air Out Temp. That would not be quite right, but probably just a constant offset. Plots show delta Temp from ambient.



    The reactor temp rises more quickly than it falls because winding the heater around the reactor conducts the heat with thermal resistance that is low compared to convection to ambient air to cool it off later.


    The long tail of the blue simulation is from the extra heat storage in the mesh after the heater is turned off. It takes a long time to make its way out to the reactor and then to ambient, likely because much of the mesh is in the vacuum and has low thermal conductivity to the reactor body.


    I chose values to make the waveforms look as similar as possible. There is no published information on heat capacities and thermal resistances in the experiment. I could get times and max Temperature (Voltage) from the spreadsheet, but had to iterate to find other values to make things fit. Someone else might be able to derive some values based on other published data.


    The simulation does not prove or disprove the existence of excess heat. It just shows that you cannot tell either way based on the shapes of the curves. The long tail might look like heat after death, but the small value is within the noise of other measurements in the same trace.


    With the values shown, the simulations show that you may need to wait a really long time to get accurate calibration constants.


    A great experiment would be to run it once with He, then run the same reactor with D keeping other parameters the same. Then differences could easily be subtracted out to show any net excess.

    I think you are using "input" to mean different things. Jed says Mizono measures input to the heater and you are talking about input to the power supply powering the heater. Your posts would be clearer if you used "heater input" or "power supply input" depending on what you are referring to.


    When power is measured to the heater, it will be very precise, whether done with an expensive power meter or just measuring V and I and multiplying. Measuring power to a resistive heater driven by DC is about as easy as it gets.

    The fan is much quieter than the axial fan I previously tried, and really doesn't seem to be blowing as hard as the axial fan.

    Blowers generally deliver air at higher pressure but lower velocity than axial fans.


    When testing, if you restrict the output flow to increase backpressure, there will be some point where the blower delivers more air (CFM) than the axial fan.

    Just as with the other Mizono-type experiments, much could be learned in the Zhang experiment from showing graphs while cycling the input power on and off at some interval longer than the thermal time constant.

    • Is the output delay for excess heat the same same as the delay with just heater power observed in the control?
    • Are there spikes in the excess or is it a constant delay from when heater power is applied?
    • Do excess heat spikes appear only with input power applied or also when it is off?
    • How long, if at all, is there heat after death?
    • Does the baseline with heater power off rise or fall gradually over time or remain the same?

    Heat is heat. If the system is sufficiently exothermic to overcome losses, and sufficient heat is returned to the reactor from the cooling system (if there is one), the reactor will run without further electrical heater input.

    But IR radiated from the heater to the mesh is not the same as the heat generated by the reaction and conducted through the mesh. If the mesh temperature is all that is important, then any version with high COP should self-sustain. But I get the impression that will not happen with this reactor, meaning the IR radiation is the key to making it work.


    If we get data with heater power on and off, that would help understand whether or not IR from the heater is important. If IR is important, that gives an avenue to understand the experiment more. What frequency gives best performance? Is the frequency/wavelength related to the size of the microvoids, cracks or grain boundaries in the Pd or Ni?

    Mizono did not have a good answer to Question 8 above (heat after death).


    In most of his papers, the graphs only show data while the heater remains on. It would be very informative to cycle the heater on and off (once an hour or day or week depending on how long to reach steady state). That would show the impulse response. Much could be learned from the time constant, shape of the curve, and power peaks especially if the same is done at similar power levels on the control.

    Is there existing knowledge or anyone's theory on why the reactor has to be so completely degassed? How does minute amounts of nitrogen or some other element stop all LENR reactions in the reactor?

    I was wondering the same thing.


    Maybe the the key is the process and particular temperatures used to degas it, not the impurities themselves. It could be that the temperature cycles condition the mesh to allow the reaction to take place.


    For instance, here is an article about annealing Ni and how high temperature annealing increases grain size.


    http://www.totalmateria.com/Article32.htm


    And this is from a 2015 paper by Ed Storms on the need to have cracks of the right size.

    (CURRENT SCIENCE, VOL. 108, NO. 4, 25 FEBRUARY 2015)


    "The interior of a crack meets this requirement. Such

    cracks form by stress relief generally on the surface of a

    material. In fact, they are observed to form on the surface

    of a PdD cathode. However, not all cracks will be active.

    Cracks having too large a gap allow D2 gas to form,

    which is well known not to fuse. A crack having too

    small a gap will not be sufficiently different from the

    conditions in the lattice to meet the requirement. Consequently,

    if a crack is the site, it must have a critical gap

    width in which a collection of hydrogen atoms can form a

    unique structure able to accomplish what normal D2 or

    deuteron ions in the lattice cannot do."


    So the heat treatment might allow the right size cracks to form.


    In other words, failure to reach over unity might be correlated with contamination but not caused by it.

    As the pressure increases, more of the heat transfer from the heater to the mesh is through convection and less through radiation. If the IR intensity is controlling the reaction rate, higher pressure should reduce the rate.


    The vacuum inside the reactor is a key difference between Mizono's and other less successful experiments.


    There is a big difference between 3 and 6000 Pa:


    Here is another difference. Notice the big difference in the color of the sheath heater referenced in the Mizuno Rothwell paper and a screenshot of the heater in the Deneum video. The sheath heater is a much darker color, making it a better blackbody radiator.



    Below is a link to an experiment where someone measured the IR from a cube with different colors on different faces. The difference between shiny black and shiny silver was a factor of 3.7.


    https://www.bbc.co.uk/bitesize/guides/ztpm7p3/revision/1

    Here is another thought to help determine the importance of heat vs. IR radiation of the mesh.


    Use a solid state relay to pulse the power to the heater and/or Halogen bulb. Run it at constant power, say 100W and measure the heat output. Then pulse it at 1000W 10% duty cycle (maybe 100ms on, 900 ms off) and measure heat. The thermal time constant should make the mesh temperature nearly equal in both cases, but the 10x pulses of IR (and probable nonlinear response) may make the heat output of the pulsed version higher.


    I would suggest a zero-crossing SSR to reduce noise to the other electronics. These switch only at the zero crossing of the AC input and do not introduce noise from switching high currents. You might use something like this one and drive the control from a signal generator:


    https://www.digikey.com/produc…SR-240D25/PB545-ND/678179

    Halogen bulbs like this are quite sensitive to cooling. They require good cooling at the rated power output, or they will burst. ...

    I would test the bulbs outside the reactor but in a similar sized enclosure to make sure they will stand up in the inside of the reactor vessel at the power levels desired. I am sure it can be done, but best to make sure before committing it to a clean reactor.

    Excellent suggestion.


    If this shows that you cannot run it at high enough power, you could use the metal pipe of the reactor as one of the electrodes (neutral if AC or negative/GND if DC). Then the bulb could be clamped or solidly attached to the cooler end of the metal pipe which would act as a heatsink for the bulb. If AC powered, you would have to be careful to have it wired correctly to avoid a shock hazard. Best to use a GFI outlet just in case.

    Here is an idea for a heater for the Mizuno replications.


    First, there are several reasons to think that the heater function is not just to heat the Nickel mesh.


    1. If heat was the only thing required, once excess heat starts, the mesh would be self-heating and the heat should continue indefinitely or even start to run away. This does not seem to happen, and turning off the heater eventually shuts it down. See Fig 28 of the 2017 paper (the 2019 paper does not show data after input power is removed).


    2. The mesh should not care if the heat comes from outside or inside, yet the R20 experiment with inside heat has much higher COP than R19 with outside heat.


    3. Once the excess heat starts, the excess is much more than the input. (In R20: 50 W input, ~250 W of excess heat, 300 W input, ~2 to 3 kW excess). When large excess is being produced, it should hardly notice that the input heater is turned off.


    This leads me to conclude that the function of the heater is more than just to raise the temperature of the mesh.


    One possibility is magnetic interaction, but this seems unlikely. The heaters are inside a steel jacket and that should provide some magnetic shielding because it gives a much lower reluctance path for the flux than through the mesh which is farther away. Also, the current and number of turns of the heater coil is low and would generate a very small magnetic field. Also, the R19 experiment should have much better magnetic coupling than R20, yet its COP is worse.


    That leaves the main possibility for the heater function to be infrared radiation. This makes sense because


    1. Low pressure D (100-300 Pa) causes more of the input power to be from radiation than conduction or convection. The excess power stops at higher D pressure.


    2. The low pressure (medium vacuum) inside the chamber effectively provides insulation and makes the temperature of the heater element (now like a bulb filament) to be higher than the mesh. The higher temperature increases the frequency of its black body IR radiation. This could explain why the lower temperature mesh cannot self-activate – its IR is at a much longer wavelength than the heater filament.


    This leaves me to conclude that a better heater would be one with higher frequency (shorter wavelength) IR radiation. A halogen bulb would do just that, and low cost halogen bulbs are available in a form factor similar to the space in the Mizono-type experiments. They come in a “T3” style in 100W, 250W, 500W and 1000W versions. The 1000W is .44 inch dia x 10.06 inch long. Here is one source, but you can get them through Amazon or hardware stores also:


    https://www.bulbs.com/product/Q1000T3-CL-120V


    This bulb could be driven from 0-130V AC or DC , 0-1 KW. A variable DC supply would work up to a couple hundred watts, but something like a Variac might work better for higher power.


    The halogen bulb is equivalent to a black body radiator at much higher temperature than the heaters used by Mizuno. Halogen bulbs have peak radiation around 1 um which is equivalent to around 3000 K. See these links:

    https://www.heliosquartz.com/p…infrared-heaters/?lang=en

    http://www.sun.org/encyclopedia/black-body-radiation


    Reactors could be made to accept either a sheath/cartridge heater or halogen bulb. First do a true replication with the heater, then try the halogen bulb. If this analysis is right, it could greatly increase the COP.


    Note that the halogen bulb has its own vacuum chamber. This might allow the reactor to operate at much higher pressure.

    A 30V supply will not be enough for some sheath heaters, and cannot get to the 500W that Mizuno used in any case.


    You might consider a Variac instead. These are electrically quieter than switching supplies or triac dimmers because the variation is done by changing the transformer coupling. They are also very inexpensive.


    Here is one that would heat up to 1000W (1000VA with a resistive load), and it is only $69. You would want to use it with a heater that is designed for 120V.


    https://www.amazon.com/YaeCCC-…64625627&s=gateway&sr=8-1