Re: [Vo]:Passive High Temperature Convective Thermal Control
No the LFTR passive control to which I refer is the fact that when the power load on the reactor lowers, the temperature rises in the liquid fluoride thorium salt which, in turn, causes it to expand. Since the salt is at critical mass, any expansion takes it below criticality which nonlinearly lowers power production and thereby lowers the temperature. The set point of the system is a particular temperature at which the power draw and the power production are equal so it is robust against variable load. On Tue, Jun 25, 2013 at 12:10 AM, Axil Axil janap...@gmail.com wrote: *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.comwrote: 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.comwrote: 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.comwrote: 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.comwrote: *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
Re: [Vo]:Passive High Temperature Convective Thermal Control
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.comwrote: 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.comwrote: 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.comwrote: 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,
Re: [Vo]:Passive High Temperature Convective Thermal Control
*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.comwrote: 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.comwrote: 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.comwrote: *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.comwrote: 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
Re: [Vo]:Passive High Temperature Convective Thermal Control
In reply to David Roberson's message of Fri, 21 Jun 2013 21:15:37 -0400 (EDT): Hi, A couple of weeks ago I gave Rossi a relatively cheap and simple method of achieving fine control over the cooling. I am waiting to see if he implements it. [snip] That sounds like a good material for Rossi to experiment with for active cooling. He might be able to reverse the thermal run away process while operating much closer to the limit of his ECAT thermal capacity. Do you know the temperature at which that these devices typically operate? [snip] Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
Re: [Vo]:Passive High Temperature Convective Thermal Control
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.comwrote: 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.comwrote: 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.
Re: [Vo]:Passive High Temperature Convective Thermal Control
*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.comwrote: 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.comwrote: 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.comwrote: 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
[Vo]:Passive High Temperature Convective Thermal Control
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.
Re: [Vo]:Passive High Temperature Convective Thermal Control
*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.
Re: [Vo]:Passive High Temperature Convective Thermal Control
That sounds like a good material for Rossi to experiment with for active cooling. He might be able to reverse the thermal run away process while operating much closer to the limit of his ECAT thermal capacity. Do you know the temperature at which that these devices typically operate? Dave -Original Message- From: Axil Axil janap...@gmail.com To: vortex-l vortex-l@eskimo.com Sent: Fri, Jun 21, 2013 9:03 pm Subject: Re: [Vo]:Passive High Temperature Convective Thermal Control A lithiumheat pipe providesenough thermal capacity and power transfer density than you could ever want or need. Gravityis not a factor. The heat transfercan be controlled by a temperature regulation of the liquid lithium returnflow. More flow results in more cooling through heat transfer through phasechange 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.
Re: [Vo]:Passive High Temperature Convective Thermal Control
http://www.lanl.gov/science/NSS/issue1_2011/story6full.shtml 500C On Fri, Jun 21, 2013 at 9:15 PM, David Roberson dlrober...@aol.com wrote: That sounds like a good material for Rossi to experiment with for active cooling. He might be able to reverse the thermal run away process while operating much closer to the limit of his ECAT thermal capacity. Do you know the temperature at which that these devices typically operate? Dave -Original Message- From: Axil Axil janap...@gmail.com To: vortex-l vortex-l@eskimo.com Sent: Fri, Jun 21, 2013 9:03 pm Subject: Re: [Vo]:Passive High Temperature Convective Thermal Control *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.
Re: [Vo]:Passive High Temperature Convective Thermal Control
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.
Re: [Vo]:Passive High Temperature Convective Thermal Control
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.
Re: [Vo]:Passive High Temperature Convective Thermal Control
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.comwrote: 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.
