Monogroove heat pipe design: insulated liquid channel with bridging wick

Claim 2

In a heat pipe having an elongated, sealed envelope, the envelope having a condensing section for operation at a relatively low temperature, an evaporation section for operation at a relatively high temperature, separate vapor and liquid channels extending between the condensing and evaporation sections, the vapor and liquid channels being in a substantially longitudinally parallel side-by-side relationship at least in the evaporation and condensing sections, wall capillary means on the inside surface of the vapor channel in at least the condensing and evaporation sections, slot capillary means extending longitudinally within the envelope at least in the evaporation and condensing sections thereof for providing fluid communication between the vapor and liquid channel, a vaporizable working fluid in the envelope, the fluid having a liquid phase and a vapor phase at the operating temperature of the heat pipe for evaporating in the high-temperature evaporation section and condensing in the low-temperature condensing section to transfer heat from the evaporation to the condensing section by phase change of the fluid, the liquid phase substantially filling the liquid channel at the operating temperature and flowing from the condensing section to the evaporation section, and the vapor phase flowing substantially independently along the vapor channel from the evaporation section to the condensing section, the improvement comprising: (a) artery means within at least the evaporation section of the liquid channel for defining an artery therein for the working fluid, said artery being spaced from and substantially free of thermal contact with the inside surface of the liquid channel to define an annulus surrounding said artery between said artery and the inside surface of the liquid channel, for retaining a continuous liquid column in said artery, and hence in the core of the liquid channel, in the event that a period of excessive heat transfer to the evaporation section of the heat pipe causes boiling and loss of liquid from said surrounding annulus, the resultant vapor in said annulus then serving to insulate and thermally isolate said artery from further liquid loss through vaporization therewithin, and to preserve the continuity of the fluid flow within the liquid channel to the evaporation section, and (b) means for providing an auxiliary liquid flow path from said artery to the slot capillary means in the evaporation section of the envelope for assuring liquid feed to the wall capillary means on the inside surface of the vapor channel in the evaporation section during such an excessive heat transfer period.

Claim 3

The improvement of claim 1 further comprising means for supporting said artery means substantially concentrically within the liquid channel.

Claim 4

The improvement of claim 1 wherein said artery means is substantially a metallic screen cylinder.

Claim 5

The improvement of claim 1 wherein said means for providing an auxiliary liquid flow path further comprises a bridging wick extending from said artery at least to the slot capillary means.

Claim 6

The improvement of claim 4 wherein said bridging wick extends through the slot capillary means, into and across the vapor channel, and into contact with the inside surface of the vapor channel substantially opposite the slot capillary means to feed liquid to the vapor channel wall capillary means farthest from the slot capillary means.

Claim 7

The improvement of claim 4 wherein said bridging wick is formed of metallic screen.

Claim 8

The improvement of claim 1 wherein said artery is sized relative to the liquid channel to preserve at least half of the original transport capacity of the heat pipe.

Claim 9

The improvement of claim 1 wherein the end of said artery closer to the condensing section extends in that direction beyond the end of the evaporation section, and further comprising plug means defining a porous plug extending across the liquid channel at said artery end for conducting liquid therethrough while preventing vapor from flowing therepast.

Claim 10

In a heat pipe having a hermetically sealed, elongated, thermally conductive envelope, the envelope having a condensing section for operation at a relatively low temperature, an evaporation section for operation at a relatively high temperature, separate longitudinal vapor and liquid channels extending the length of the envelope in a substantially parallel side-by-side relationship, wall capillary means on the inside surface of the vapor channel in at least the condensing and evaporation sections thereof, slot capillary means extending longitudinally within the envelope at least in the evaporation and condensing sections thereof for providing fluid communication between the vapor and liquid channels, a vaporizable working fluid in the envelope, the fluid having a liquid phase and a vapor phase at the operating temperature of the heat pipe for evaporating in the high-temperature evaporation section and condensing in the low-temperature condensing section to transfer heat from the evaporation to the condensing section by phase change of the fluid, the liquid phase substantially filling the liquid channel at the operating temperature and flowing from the condensing section to the evaporation section, and the vapor phase flowing substantially independently along the vapor channel from the evaporation section to the condensing section, the improvement comprising: (a) cylindrical stainless steel mesh screen artery insert means supported substantially concentrically within the liquid channel within at least the evaporation section of the liquid channel for defining an artery therein for the working fluid, the end of said artery closer to the condensing section extending in that direction beyond the end of the evaporation section, said artery being sized relative to the liquid channel to preserve at least 90% of the original transport capacity of the heat pipe itself, and being spaced from and substantially free of thermal contact with the inside surface of the liquid channel to define an annulus surrounding said artery between said artery and the inside surface of the liquid channel, for retaining a continuous liquid column in said artery, and hence in the core of the liquid channel, in the event that a period of excessive heat transfer to the evaporation section of the heat pipe causes boiling and loss of liquid from said surrounding annulus, the resultant vapor in said annulus then serving to insulate and thermally isolate said artery from further liquid loss through vaporization therewithin, and to preserve the continuity of the fluid flow within the liquid channel to the evaporation section, (b) stainless steel mesh screen plug means defining a porous plug extending across the liquid channel at the end of said artery closer to the condensing section for conducting liquid therethrough while preventing vapor from flowing therepast, and (c) a stainless steel mesh screen bridging wick extending from said artery through the slot capillary means, into and across the vapor channel, and into contact with the inside surface of the vapor channel substantially opposite the slot capillary means, to provide an auxiliary liquid flow path from said artery to the slot capillary means in the evaporation section of the envelope and also to feed liquid directly to the vapor channel wall capillary means farthest from the slot capillary means, thereby assuring a relatively uniform liquid feed to the wall capillary means throughout the inside surface of the vapor channel in the evaporation section during such an excessive heat transfer period.

Claim 11

In a heat pipe having a hermetically sealed, elongated, thermally conductive envelope, the envelope having a condensing section for operation at a relatively low temperature, an evaporation section for operation at a relatively high temperature, separate longitudinal vapor and liquid channels extending the length of the envelope in a substantially parallel side-by-side relationship, wall capillary means on the inside surface of the vapor channel in at least the condensing and evaporation sections thereof, slot capillary means extending longitudinally within the envelope at least in the evaporation and condensing sections thereof for providing fluid communication between the vapor and liquid channels, a vaporizable working fluid in the envelope, the fluid having a liquid phase and a vapor phase at the operating temperature of the heat pipe for evaporating in the high-temperature evaporation section and condensing in the low-temperature condensing section to transfer heat from the evaporation to the condensing section by phase change of the fluid, the liquid phase substantially filling the liquid channel at the operating temperature and flowing from the condensing section to the evaporation section, and the vapor phase flowing substantially independently along the vapor channel from the evaporation section to the condensing section, the improvement comprising: (a) cylindrical stainless steel mesh screen artery insert means supported substantially concentrically within the liquid channel within at least the evaporation section of the liquid channel for defining an artery therein for the working fluid, the end of said artery closer to the condensing section extending in that direction beyond the end of the evaporation section, said artery being sized relative to the liquid channel to preserve at least 90% of the original transport capacity of the heat pipe itself, and being spaced from and substantially free of thermal contact with the inside surface of the liquid channel to define an annulus surrounding said artery between said artery and the inside surface of the liquid channel, for retaining a continuous liquid column in said artery, and hence in the core of the liquid channel, in the event that a period of excessive heat transfer to the evaporation section of the heat pipe causes boiling and loss of liquid from said surrounding annulus, the resultant vapor in said annulus then serving to insulate and thermally isolate said artery from further liquid loss through vaporization therewithin, and to preserve the continuity of the fluid flow within the liquid channel to the evaporation section, (b) stainless steel mesh screen plug means defining a porous plug extending across the liquid channel at the end of said artery closer to the condensing section for conducting liquid therethrough while preventing vapor from flowing therepast, and (c) a stainless steel mesh screen bridging wick extending from said artery through the slot capillary means, into and across the vapor channel, and into contact with the inside surface of the vapor channel substantially opposite the slot capillary means, to provide an auxiliary liquid flow path from said artery to the slot capillary means in the evaporation section of the envelope and also to feed liquid directly to the vapor channel wall capillary means farthest from the slot capillary means, thereby assuring a relatively uniform liquid feed to the wall capillary means throughout the inside surface of the vapor channel in the evaporation section during such an excessive heat transfer period.

Claim 12

In a method for preserving the continuity of the fluid flow within the liquid channel to the evaporation section of a heat pipe, the heat pipe having an elongated, sealed envelope, the envelope having a condensing section for operation at a relatively low temperature, an evaporation section for operation at a relatively high temperature, separate vapor and liquid channels extending between the condensing and evaporation sections, the vapor and liquid channels being in a substantially longitudinally parallel side-by-side relationship at least in the evaporation and condensing sections, wall capillary means on the inside surface of the vapor channel in at least the condensing and evaporation sections, slot capillary means extending longitudinally within the envelope at least in the evaporation and condensing sections thereof for providing fluid communication between the vapor and liquid channels, a vaporizable working fluid in the envelope, the fluid having a liquid phase and a vapor phase at the operating temperature of the heat pipe for evaporating in the high-temperature evaporation section and condensing in the low-temperature condensing section to transfer heat from the evaporation to the condensing section by phase change of the fluid, the liquid phase substantially filling the liquid channel at the operating temperature and flowing from the condensing section to the evaporation section, and the vapor phase flowing substantially independently along the vapor channel from the evaporation section to the condensing section, the improvement comprising: (a) retaining a continuous liquid column of the working fluid within an artery located within at least the evaporation section of the liquid channel, (b) supporting the artery spaced from and substantially free of thermal contact with the inside surface of the liquid channel to define an annulus surrounding the artery between the artery and the inside surface of the liquid channel, such that during a period in which excessive heat transfer to the evaporation section of the heat pipe causes boiling and loss of liquid from the surrounding annulus, the resultant vapor in the annulus then serves to insulate and thermally isolate the artery from further liquid loss through vaporization therewithin, thereby retaining the continuous liquid column in the artery, and hence in the core of the liquid channel, and preserving the continuity of the fluid flow within the liquid channel to the evaporation section, and (c) feeding liquid from the artery to the wall capillary means on the inside surface of the vapor channel in the evaporation section, during such an excessive heat transfer period, through an auxiliary liquid flow path from the artery to the slot capillary means in the evaporation section of the envelope.

Claim 13

In a method for preserving the continuity of the fluid flow within the liquid channel to the evaporation section of a heat pipe, the heat pipe having an elongated, sealed envelope, the envelope having a condensing section for operation at a relatively low temperature, an evaporation section for operation at a relatively high temperature, separate vapor and liquid channels extending between the condensing and evaporation sections, the vapor and liquid channels being in a substantially longitudinally parallel side-by-side relationship at least in the evaporation and condensing sections, wall capillary means on the inside surface of the vapor channel in at least the condensing and evaporation sections, slot capillary means extending longitudinally within the envelope at least in the evaporation and condensing sections thereof for providing fluid communication between the vapor and liquid channels, a vaporizable working fluid in the envelope, the fluid having a liquid phase and a vapor phase at the operating temperature of the heat pipe for evaporating in the high-temperature evaporation section and condensing in the low-temperature condensing section to transfer heat from the evaporation to the condensing section by phase change of the fluid, the liquid phase substantially filling the liquid channel at the operating temperature and flowing from the condensing section to the evaporation section, and the vapor phase flowing substantially independently along the vapor channel from the evaporation section to the condensing section, the improvement comprising: (a) retaining a continuous liquid column of the working fluid within an artery located within at least the evaporation section of the liquid channel, (b) supporting the artery spaced from and substantially free of thermal contact with the inside surface of the liquid channel to define an annulus surrounding the artery between the artery and the inside surface of the liquid channel, such that during a period in which excessive heat transfer to the evaporation section of the heat pipe causes boiling and loss of liquid from the surrounding annulus, the resultant vapor in the annulus then serves to insulate and thermally isolate the artery from further liquid loss through vaporization therewithin, thereby retaining the continuous liquid column in the artery, and hence in the core of the liquid channel, and preserving the continuity of the fluid flow within the liquid channel to the evaporation section, and (c) feeding liquid from the artery to the wall capillary means on the inside surface of the vapor channel in the evaporation section, during such an excessive heat transfer period, through an auxiliary liquid flow path from the artery to the slot capillary means in the evaporation section of the envelope.

Claim 14

The method of claim 10 further comprising supporting the artery substantially concentrically within the liquid channel.

Claim 15

The method of claim 10 wherein the artery is substantially a metallic screen cylinder.

Claim 16

The method of claim 10 wherein said step of feeding liquid to the wall capillary means further comprises feeding the liquid by means of a bridging wick extending from the artery at least to the slot capillary means.

Claim 17

The method of claim 13 further comprising feeding liquid from the artery to the vapor channel wall capillary means farthest from the slot capillary means through a bridging wick which extends through the slot capillary means, into and across the vapor channel, and into contact with the inside surface of the vapor channel substantially opposite the slot capillary means.

Claim 18

The method of claim 13 wherein the bridging wick is formed of metallic screen.

Claim 19

The method of claim 10 wherein the artery is sized relative to the liquid channel to perserve at least half of the original transport capacity of the heat pipe.

Claim 20

The method of claim 10 wherein the end of the artery closer to the condensing section extends in that direction beyond the end of the evaporation section, and further comprising preventing vapor from flowing therepast using a porous plug extending across the liquid channel at the artery end, while conducting liquid therethrough.

Claim 21

In a method for preserving the continuity of the fluid flow within the liquid channel to the evaporation section of a heat pipe, the heat pipe having a hermetically sealed, elongated, thermally conductive envelope, the envelope having a condensing section for operation at a relatively low temperature, an evaporation section for operation at a relatively high temperature, separate longitudinal vapor and liquid channels extending the length of the envelope in a substantially parallel side-by-side relationship, wall capillary means on the inside surface of the vapor channel in at least the condensing and evaporation sections thereof, slot capillary means extending longitudinally within the envelope at least in the evaporation and condensing sections thereof for providing fluid communication between the vapor and liquid channels, a vaporizable working fluid in the envelope, the fluid having a liquid phase and a vapor phase at the operating temperature of the heat pipe for evaporating in the high-temperature evaporation section and condensing in the low-temperature condensing section to transfer heat from the evaporation to the condensing section by phase change of the fluid, the liquid phase substantially filling the liquid channel at the operating temperature and flowing from the condensing section to the evaporation section, and the vapor phase flowing substantially independently along the vapor channel from the evaporation section to the condensing section, the improvement comprising: (a) retaining a continuous liquid column of the working fluid within a cylindrical stainless steel mesh screen artery insert located within at least the evaporation section of the liquid channel, the end of the artery closer to the condensing section extending in that direction beyond the end of the evaporation section, and the artery being sized relative to the liquid channel to preserve at least 90% of the original transport capacity of the heat pipe itself, (b) supporting the artery substantially concentrically within the liquid channel and spaced from and substantially free of thermal contact with the inside surface of the liquid channel to define an annulus surrounding the artery between the artery and the inside surface of the liquid channel, such that during a period in which excessive heat transfer to the evaporation section of the heat pipe causes boiling and loss of liquid from the surrounding annulus, the resultant vapor in the annulus then serves to insulate and thermally isolate the artery from further liquid loss through vaporization therewithin, thereby retaining a continuous liquid column in the artery, and hence in the core of the liquid channel, and preserving the continuity of the fluid flow within the liquid channel to the evaporation section, (c) preventing vapor from flowing past the end of the artery closer to the condensing section using a stainless steel mesh screen porous plug extending across the liquid channel at the artery end, while conducting liquid therethrough, and (d) feeding liquid from the artery relatively uniformly to the wall capillary means on the inside surface of the vapor channel in the evaporation section, during such an excessive heat transfer period, through a stainless steel mesh screen bridging wick extending from the artery through the slot capillary means, into and across the vapor channel, and into contact with the inside surface of the vapor channel substantially opposite the slot capillary means, the wick providing an auxiliary liquid flow path from the artery to the slot capillary means and to the vapor channel wall capillary means farthest from the slot capillary means.

Claim 22

In a method for preserving the continuity of the fluid flow within the liquid channel to the evaporation section of a heat pipe, the heat pipe having a hermetically sealed, elongated, thermally conductive envelope, the envelope having a condensing section for operation at a relatively low temperature, an evaporation section for operation at a relatively high temperature, separate longitudinal vapor and liquid channels extending the length of the envelope in a substantially parallel side-by-side relationship, wall capillary means on the inside surface of the vapor channel in at least the condensing and evaporation sections thereof, slot capillary means extending longitudinally within the envelope at least in the evaporation and condensing sections thereof for providing fluid communication between the vapor and liquid channels, a vaporizable working fluid in the envelope, the fluid having a liquid phase and a vapor phase at the operating temperature of the heat pipe for evaporating in the high-temperature evaporation section and condensing in the low-temperature condensing section to transfer heat from the evaporation to the condensing section by phase change of the fluid, the liquid phase substantially filling the liquid channel at the operating temperature and flowing from the condensing section to the evaporation section, and the vapor phase flowing substantially independently along the vapor channel from the evaporation section to the condensing section, the improvement comprising: (a) retaining a continuous liquid column of the working fluid within a cylindrical stainless steel mesh screen artery insert located within at least the evaporation section of the liquid channel, the end of the artery closer to the condensing section extending in that direction beyond the end of the evaporation section, and the artery being sized relative to the liquid channel to preserve at least 90% of the original transport capacity of the heat pipe itself, (b) supporting the artery substantially concentrically within the liquid channel and spaced from and substantially free of thermal contact with the inside surface of the liquid channel to define an annulus surrounding the artery between the artery and the inside surface of the liquid channel, such that during a period in which excessive heat transfer to the evaporation section of the heat pipe causes boiling and loss of liquid from the surrounding annulus, the resultant vapor in the annulus then serves to insulate and thermally isolate the artery from further liquid loss through vaporization therewithin, thereby retaining a continuous liquid column in the artery, and hence in the core of the liquid channel, and preserving the continuity of the fluid flow within the liquid channel to the evaporation section, (c) preventing vapor from flowing past the end of the artery closer to the condensing section using a stainless steel mesh screen porous plug extending across the liquid channel at the artery end, while conducting liquid therethrough, and (d) feeding liquid from the artery relatively uniformly to the wall capillary means on the inside surface of the vapor channel in the evaporation section, during such an excessive heat transfer period, through a stainless steel mesh screen bridging wick extending from the artery through the slot capillary means, into and across the vapor channel, and into contact with the inside surface of the vapor channel substantially opposite the slot capillary means, the wick providing an auxiliary liquid flow path from the artery to the slot capillary means and to the vapor channel wall capillary means farthest from the slot capillary means.