Abstract An improved heat pipe capable of conveying a greater heat flux than a conventional heat pipe is provided in practice of this invention. A heat pipe transfers heat from a heat source to a heat sink in the form of latent heat of vaporization of a fluid within the heat pipe. Hot vapor transfers heat from the heat source to the heat sink. Condensed liquid is returned from heat sink to the heat source through porous capillary material due to surface tension forces. The heat flux obtainable is limited by the available flow of returning liquid. In the improved heat pipe, the flow paths for liquid and vapor are serially segmented by impermeable barriers transverse to the direction of heat flow so that the distance of liquid flow in each segment is minimized. In zero gravity the heat flux obtainable is approximately proportional to the number of serial segments N into which the heat pipe is divided, that is, if the heat is transferred serially through N segments approximately N times the heat flux is possible as compared with a conventional heat pipe of the same overall dimensions. When operating against a gravity head, the maximum heat flux is about N2 times the heat flux of a conventional heat pipe. Thus a heat pipe segmented into 10 serial segments has approximately 10 to 100 times the maximum heat flux capacity of an unsegmented heat pipe of the same cross section and total length.
An improved heat pipe comprising: a closed chamber; a fluid, comprising a liquid and its vapor in the chamber; a body of capillary material in the chamber for conveying liquid from relatively cooler regions to relatively warmer regions; a vapor way in the chamber for conveying vapor from relatively warmer regions to relatively cooler regions; and additional capillary material in the chamber having a lower effective capillary surface to volume ratio delta than a principal portion of the body of capillary material, and wherein the amount of fluid in the chamber is such that said additional capillary material is not completely saturated with liquid during operation.
Claim 2
Dependent Claim
106 words
An improved heat pipe comprising: a closed chamber; a fluid, comprising a liquid and its vapor in the chamber; a body of capillary material in the chamber for conveying liquid from relatively cooler regions to relatively warmer regions; a vapor way in the chamber for conveying vapor from relatively warmer regions to relatively cooler regions; and additional capillary material in the chamber having a lower effective capillary surface to volume ratio delta than a principal portion of the body of capillary material, and wherein the amount of fluid in the chamber is such that said additional capillary material is not completely saturated with liquid during operation.
Claim 3
Dependent Claim
145 words
An improved heat pipe comprising: a closed chamber; a fluid, comprising a liquid and its vapor, in the chamber; a body of capillary material in the chamber for conveying liquid from relatively cooler regions to relatively warmer regions; a vapor way in the chamber for conveying vapor from relatively warmer regions to relatively cooler regions; means for increasing the maximum heat flux capacity of the heat pipe comprising a partition having at least an impermeable layer and dividing the chamber into two closed chambers in thermal contact through the partition; and additional capillary material in at least one of the chambers having a lower effective capillary surface to volume ratio delta than a principal portion of the body of capillary material, and wherein the amount of fluid in the chamber is such that said additional capillary material is not completely saturated with liquid during operation.
Claim 4
Dependent Claim
145 words
An improved heat pipe comprising: a closed chamber; a fluid, comprising a liquid and its vapor, in the chamber; a body of capillary material in the chamber for conveying liquid from relatively cooler regions to relatively warmer regions; a vapor way in the chamber for conveying vapor from relatively warmer regions to relatively cooler regions; means for increasing the maximum heat flux capacity of the heat pipe comprising a partition having at least an impermeable layer and dividing the chamber into two closed chambers in thermal contact through the partition; and additional capillary material in at least one of the chambers having a lower effective capillary surface to volume ratio delta than a principal portion of the body of capillary material, and wherein the amount of fluid in the chamber is such that said additional capillary material is not completely saturated with liquid during operation.