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. >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>> >> >
