*rather the issue is the _control_ of that variance.* As I understand your intent, your interest is the passive control of the variance.
It seems to me, that if there is a mechanism of parameter control in the operation of the reactor, control of that parameter can be either active or passive or both. In the LFTR, there is a sacrificial failsafe freeze plug concept that passively protects the reactor from meltdown. I think this is what you are after to avoid a catastrophic runaway of the E-cat. This passive failsafe can exist in parallel with a passive or active control of the reactor. If the hydrogen gas gets too hot a freeze plug could melt to expel the hydrogen gas into a dedicated dump tank in the same way as is done in the LFTR with the molten salt.. On Tue, Jun 25, 2013 at 12:21 AM, James Bowery <jabow...@gmail.com> wrote: > First of all, variable conductance is not to the point. The issue is not > whether one can vary the conductance or anything else -- rather the issue > is the _control_ of that variance. > > Secondly, the technology you describe involves a solid phase. My request > was for a cite of prior art for the technology you describe. The > Thermacore technology does not fit your description. > > > On Sat, Jun 22, 2013 at 9:03 PM, Axil Axil <janap...@gmail.com> wrote: > >> *http://www.thermacore.com/products/variable-conductance-heat-pipe.aspx* >> ** >> *Heat pipes have this ability for Variable Conductance, here is what >> thermacore does. * >> ** >> *How Does a Variable Conductance Heat Pipe Work?* >> >> All heat pipes can be made variable conductance by introducing a small >> mass of Non conducting gas NCG(shown schematically below). Because NCG is >> swept to the end of the condenser by the condensing working fluid vapor, it >> blocks a portion of the condenser, effectively reducing its conductance. If >> the ambient temperature increases, decreasing the available temperature >> difference between the condenser and the ambient, the operating temperature >> of the heat pipe will increase. This causes the operating pressure (i.e, >> saturation pressure of the working fluid at the heat pipe operating >> temperature) to increase, compressing the NCG into a smaller volume. The >> result is that more of the condenser area is available to condensing >> working fluid. This limits the increase in the operating temperature of the >> heat pipe and the component mounted to it, much as in the case of a >> Constant Conductance Heat Pipe (CCHP). Ideally, the increased conductance >> of the condenser offsets the increase in the ambient temperature and the >> heat pipe operates at a constant temperature. >> >> The degree of control depends on the working fluid saturation curve, the >> desired operating temperature set point, the ranges of ambient temperature >> and heat load and the volume of gas relative to the volume of the vapor >> space in the condenser. >> >> >> >> >> On Sat, Jun 22, 2013 at 8:43 PM, James Bowery <jabow...@gmail.com> wrote: >> >>> If you have indeed come up with something that is as elegant as the >>> passive power output from LFTR for the E-Cat HT, my apologies for >>> misunderstanding your proposal and my congratulations. >>> >>> Can you cite any patent numbers that use this sort of passive >>> temperature control using Li heat pipes? Can you select the desired >>> operating temperature at the reactor surface with it, as I believe the free >>> convection approach can? >>> >>> >>> On Sat, Jun 22, 2013 at 12:26 AM, Axil Axil <janap...@gmail.com> wrote: >>> >>>> A passive thermostat that reduces the flow of lithium liquid in a heat >>>> pipe is what you were after. >>>> >>>> It uses the same passive expansion mechanism that is used in the LFTR. >>>> >>>> What is the problem? >>>> >>>> >>>> >>>> >>>> On Fri, Jun 21, 2013 at 11:26 PM, James Bowery <jabow...@gmail.com>wrote: >>>> >>>>> You must not be much of an engineer if you are so willing to blow off >>>>> explicit mention of passive control, Axil. Do you have any engineering >>>>> background in critical systems -- by which I mean systems that, if they >>>>> fail, they kill people? >>>>> >>>>> I do and they didn't. >>>>> >>>>> >>>>> On Fri, Jun 21, 2013 at 10:21 PM, James Bowery <jabow...@gmail.com>wrote: >>>>> >>>>>> You sacrificed passive control without acknowledging that was the >>>>>> goal of my proposal. >>>>>> >>>>>> >>>>>> On Fri, Jun 21, 2013 at 8:03 PM, Axil Axil <janap...@gmail.com>wrote: >>>>>> >>>>>>> *A *lithium heat pipe provides enough thermal capacity and power >>>>>>> transfer density than you could ever want or need. Gravity is not a >>>>>>> factor. >>>>>>> >>>>>>> >>>>>>> >>>>>>> The heat transfer can be controlled by a temperature regulation of >>>>>>> the liquid lithium return flow. More flow results in more cooling >>>>>>> through >>>>>>> heat transfer through phase change from liquid to vapor. This phase >>>>>>> change >>>>>>> mechanism is 1000 more powerful than convection cooling. ** >>>>>>> >>>>>>> * * >>>>>>> >>>>>>> * * >>>>>>> >>>>>>> >>>>>>> On Fri, Jun 21, 2013 at 8:42 PM, James Bowery <jabow...@gmail.com>wrote: >>>>>>> >>>>>>>> Systems like the LFTR have passive high temperature thermal control >>>>>>>> based on thermal expansion of a near-critical mass density. As the >>>>>>>> temperature increases, thermal expansion produces a rapid drop in power >>>>>>>> production thereby stabilizing the reactor core. >>>>>>>> >>>>>>>> Systems like the E-Cat HT are solid state and, in any event, are >>>>>>>> not dependent on critical mass density, but another approach to >>>>>>>> utilization >>>>>>>> of thermal expansion might work: >>>>>>>> >>>>>>>> Thermal Convection >>>>>>>> >>>>>>>> To make thermal convection work, passive (free) convective forces >>>>>>>> must be large enough to move enough thermal capacity past the power >>>>>>>> source >>>>>>>> and must be in a regime where the rate of cooling exceeds the power >>>>>>>> production at the target temperature. >>>>>>>> >>>>>>>> The 3 variables one has to play with to reach the target >>>>>>>> temperature are material thermal properties, power density of the >>>>>>>> E-Cat and >>>>>>>> g forces. Of these three, only g forces and power density are >>>>>>>> amenable to >>>>>>>> continuous alteration via centrifugation and reactor fabrication >>>>>>>> respectively. >>>>>>>> >>>>>>>> In my ultracentrifugal rocket engine patent, the g-forces are so >>>>>>>> enormous that enormous fluid flow, hence enormous thermal capacity flow >>>>>>>> enables relatively small heat exchange surfaces to cool the engine. A >>>>>>>> material that might be worthwhile analyzing in this regard is NaCl >>>>>>>> (sodium >>>>>>>> chloride) with a melting point near the high end of the E-Cat HT, and a >>>>>>>> heat capacity comparable to that of H2O. It is problematic to run >>>>>>>> molten >>>>>>>> NaCl in an ultracentrifuge due to material strength limits as they >>>>>>>> detemper >>>>>>>> at high temperature. >>>>>>>> >>>>>>>> On the other hand, power density might be reduced to the point that >>>>>>>> the heat capacity flow rate, even under only 1-g, might be sufficient. >>>>>>>> >>>>>>>> Clearly some arithmetic needs to be done here. >>>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> >
