RU2699116C2 - Metal thermal heat flow pipe - Google Patents

Abstract

FIELD: pipelines.

SUBSTANCE: metal heat pipe of flat type consisting of housing with evaporation, transport and condenser zones, heat carrier supply system, capillary-porous wick formed on the inner surface of the opposite walls of the housing with formation of a gap in its central part, in which there is a system of vapor discharge channels. Supply of heat carrier to evaporation zone of heat pipe is carried out due to system of porous channels for heat carrier, consisting of upper and lower capillary-porous wicks on inner surfaces of housing and arranged between rows of capillary-porous columns of arbitrary cross-section. Steam discharge duct system in evaporation, transport and condenser zones is a spatial cellular structure formed between external surfaces of upper and lower capillary-porous wicks of surfaces of housing and walls of capillary-porous columns, wherein ratio of heat-transfer volume of heat pipe and steam volume is in range from 0.5:1 to 4.0:1.

EFFECT: disclosed is a metal heat pipe of flat type.

8 cl, 12 dwg

Description

The invention relates to heat engineering, namely to heat pipes of a flat type, which can be used for cooling printed circuit boards of electronic equipment.

A flat type heat pipe is known according to the USSR author's certificate No. 1673824 (class IPC F28D 15/02, priority date 02/07/1989) [1], comprising a body, the opposite walls of which are provided with a capillary-porous structure with a system of steam channels in the central part of the body, moreover, the capillary-porous structure is located with the formation of a gap in the Central part of the housing, the system of vapor channels is formed by a flat metal mesh installed in this gap and adjacent to the capillary-porous structure.

The system of steam channels formed in the central part of the heat pipe of this design allows the steam to move in a plane in certain directions and transfer heat from the heating zone to the cooling zone. The working fluid can move in a porous medium of the heat pipe in an arbitrary direction.

The disadvantages of this design are:

1. The irrational use of the central space in this design, since a significant part of the useful section of the gap formed in the central part of the housing in which the mesh is placed, is blocked by the metal wire from which it is woven. As a result of this, the thickness of the mesh should be 1.5-2 times greater than the required diameter of the vapor channels. For example, when using water as a heat transfer medium so that at low temperatures (from 5 to 18 ° C) the hydraulic resistance of the vapor channels is small and the heat pipe has high effective thermal conductivity, the diameter of the channels should be at least 2 mm. To fulfill this condition, a mesh having a thickness of 3-4 mm is required. As a result, the use of a flat grid to form steam channels leads to an increase in the thickness of the heat pipe. As a result, its mass increases, which makes it difficult to use this heat pipe, for example, in space technology.

2. To reduce the thermal resistance and mass of a flat heat pipe, it is necessary to use a housing with as little wall thickness as possible, for example, less than 0.3 mm. However, in this design it is impossible to do this, because due to its low mechanical strength it is almost impossible to press the mesh tightly to the capillary-porous wick, therefore, the heat transfer characteristics of such a heat pipe will be worse.

Flat type metal heat pipe described in RF patent for invention No. 2457417 (class IPC F28D 15/00, priority date 11/22/2010) [2], contains a housing, a capillary-porous wick formed on the inner surfaces of the opposite walls of the housing with the formation of a gap in its central part, which contains a system of steam drainage channels, formed by one or two corrugated and perforated plates, consisting of one or more layers of a metal mesh, on the surface of which a capillary-porous metal powder structure. In the side walls of the corrugated perforated plate between the walls from which it is formed, slots (arteries) are formed with a size equal to or greater than the pore size of the capillary-porous structure. The evaporation zone and the condensation zone of the heat pipe, including, but not limited to, steam channels, special channels for transporting liquid and the working surface of the main wick, located in one housing, are located in mutually perpendicular planes.

The disadvantages of this design of a flat heat pipe are:

1. The corrugated perforated plate connecting the condenser and the evaporator serves as an additional wick and facilitates the transport of the coolant from the condensation zone to the evaporation zone due to capillary forces, and the corrugated perforated plate located in a parallel plane and connected to each other by corrugation vertices does not participate in the heat carrier transportation therefore, when summing up the heat load, the opposite sides of the flat heat pipe have different temperature gradients between the evaporator and a capacitor that leads to local draining of the porous medium in the evaporation zone and, correspondingly, local overheating of the heat pipe.

2. Arteries formed in the corrugations of the heat pipe are located not only in the condenser, but also in the evaporation zones, which leads to the formation of a vapor “bubble” at high heat loads and, as a consequence, the cessation of the functioning of the arteries as a whole.

3. The corrugated perforated plate blocks the opposite sides of the GTP evaporation zone, which further complicates the operation of a flat heat pipe at high specific heat loads, since the heat carrier only enters the evaporation zone from the condensation zone due to capillary forces and the coolant located on the opposite, not heat-loaded, is not used side.

4. The joints of corrugated perforated plates with other structural elements of a flat heat pipe creates a place of inhomogeneity of porous media, providing transportation of the coolant to the evaporation zone. The porosity at the joints instead of 50 ÷ 70% can be reduced to 20% or less. In the evaporator, the junction of the corrugated perforated plates with the side walls of a flat heat pipe, along almost the entire length, is a solid line that divides it into separate zones that are not interconnected by the fluid flow.

Heat pipe designs described in US Pat. No. 8,356,657 (CL IPC F28D 15/02, priority date 12/19/2007) [3] and No. 9459050 (CL IPC B22F 3/11, F28D 15/02, priority date 5/9/2012 ) [4] is based on the device of a heat pipe having a wick structure in the form of a sintered grating, including a plurality of tie walls of a certain length, width and height, located parallel with the wick fluid in the longitudinal direction along the respective lengths. Moreover, the corresponding lengths are greater than the corresponding widths and the corresponding height, a plurality of coupling walls adjacent to each other, and spaced apart to form pairs between them, a plurality of connecting coupling walls for the wick fluid to flow between adjacent walls in a transverse second direction, substantially perpendicular to the longitudinal first direction, and a steam chamber containing a sintered trellis wick structure, a steam chamber having an inner condensation surface and an inner ennyuyu evaporator surface, wherein a plurality of clamping walls and a plurality of connecting walls configured for clamping the wick liquids in the longitudinal first and second transverse directions. The direction in which the steam flows corresponds to the direction of heat transfer of the heat pipe of a given design from the heater to the refrigerator.

The disadvantages of this design of the heat pipe are:

1. The design of the heat pipe is made in such a way that during operation there may be overheating of its working section due to the fact that there is no equalization of steam pressure in between the individual channels.

2. The heat transfer of this heat pipe is not sufficient due to the large hydraulic resistance in the wick cavity due to its extensive network of channels.

3. This heat pipe is designed to transfer heat over short distances, since its height does not exceed 15 mm, so it cannot be universal in use.

The closest technical solution, and therefore taken as a prototype, is US patent No. 6293332 "The design of ultra-thin thermal plate" (CL IPC F28D 15/02, priority date 09/25/2001) [5].

The structure of an ultra-thin heat plate (flat heat pipe) consists of a pair of external bodies located one above the other, having flat surfaces, and supporting bodies inserted between the external bodies. Each of the external bodies is made in the form of a flat metal plate, which on the inner surface can have a capillarity function. These supporting bodies have an elongated shape of various configurations. The structure of the supporting bodies consists of a pair of opposite flat surfaces and an internal cavity. The flat surfaces of the support bodies are connected to the internal flat surfaces of the external bodies. The internal cavity in the supporting bodies is located along their entire length, and on the inner surface of this cavity there are many capillaries, the length of which coincides with the length of the internal cavity of the supporting bodies. The internal cavity and capillaries of the supporting bodies are made by stamping. The above external bodies and supporting bodies are interconnected by a variety of welded points. A wick structure is formed at the edges of the heat plate to form an unbroken fluid flow throughout the volume of the heat plate.

The fluid cavity of the heat plate is formed by the capillaries of the external bodies and supporting bodies, as well as the wick structure at the edges of the heat plate.

The vapor cavity is the free space of the internal cavities of the supporting bodies between the upper and lower plates of the external bodies.

The disadvantages of this design of the heat plate are:

1. since the vapor cavity is divided into many separate channels, there is no equalization of the vapor pressure, which can lead to local overheating of the working section of the heat plate;

2. the liquid cavity has the form of a branched network of channels delimited by sections of the vapor cavity, as a result of this there is a large hydraulic resistance, which limits the heat transfer ability of the heat plate;

3. the wick structure is formed by many specially formed capillaries made by stamping - a narrow range of possible values of capillary diameters leads to limitations both in mass transfer and in the permissible angle of inclination of the heat plate. The greater the angle of inclination of the heat plate, the lower the mass velocity of the coolant and the lower the height at which the capillaries, with a narrow range of possible diameters, can raise the coolant inside the heat plate;

4. spot welding causes local heating and deformation of supporting bodies having capillary channels inside an ultra-thin heat plate. This leads to local changes in the hydraulic resistance of the capillary channels and affects the heat transfer of the heat plate.

The objective of the claimed design of a metal heat pipe of a flat type with a system of steam channels of a spatial structure is the rational use of the central space of a flat heat pipe, increase its performance at high specific heat loads, increase its effective thermal conductivity, heat transfer over long distances and expand its applicability by reducing weight characteristics.

The problem is achieved due to the fact that in the known design of a flat type heat pipe, including a housing with evaporation, transport and condenser zones, a coolant supply system, a capillary-porous wick formed on the inner surface of the opposite walls of the housing with the formation of a gap in its central part, in which the system of steam drainage channels is located, according to the claimed technical solution, the coolant (liquid) is supplied to the evaporation zone of the heat pipe due to the topics of porous coolant channels, consisting of upper and lower capillary-porous wicks formed on the inner surfaces of the walls of the body and located between them and adjacent to them in rows of capillary-porous columns of arbitrary section, for example, round, and, if necessary, rectilinear porous partitions (additional coolant channels). This design forms a spatial cellular structure of a system of steam drainage channels located between the outer surfaces of the upper and lower capillary-porous wicks of the housing surfaces and the walls of the capillary-porous columns, and the ratio of heat-transfer and vapor volume is in the range from 0.5: 1 to 4.0: one.

The use of the claimed design in addition to the implementation of the tasks, provides high tensile strength from internal pressure, which is important when using, for example, low-temperature boiling fluids.

It was experimentally determined that the ratio of the coolant (liquid) and steam volume is in the range from 0.5: 1 to 4.0: 1.

When the ratio of heat transfer and vapor volume is less than 0.5: 1, the heat transfer in the heat pipe is limited as a result of a rapid increase in temperature in the evaporation zone of the heat pipe, caused by the drying of the porous medium of the coolant channels, when the mass flow of the coolant through the system of porous channels cannot compensate for the mass rate of evaporation coolant in steam channels.

When the ratio of the heat transfer and vapor volume is more than 4.0: 1, the heat transfer in the heat pipe is limited as a result of the increase in the temperature of the evaporator, without drying the porous medium, when the transmitting ability of the steam channel ceases to correspond to the mass rate of evaporation of the coolant.

A variant of the inventive metal heat pipe of a flat type is a design in which artery channels are made on the inner surfaces of the body plates, contributing to an increase in the coolant supply to the evaporation zone.

Another design option of the inventive flat-type metal heat pipe with a system of steam drainage channels of a spatial cellular structure is a structure in which steam drainage channels between rows of capillary-porous columns are made with an arbitrary step on the inner side of the upper and lower capillary-porous wicks adjacent to the inner surfaces of the housing .

The next design option of the inventive flat type metal heat pipe with a system of steam drainage channels of a spatial cellular structure located in the evaporation zone is a heat pipe design with capillary-porous arteries for the coolant in the form of rectilinear porous bridges made at random intervals between rows of capillary-porous columns.

Variants of the design of the inventive heat pipe with a system of steam outlet channels of a spatial cellular structure are various combinations of structural elements of the inventive heat pipe, namely, channels-arteries, on the inner surfaces of the housing, steam channels and rectilinear capillary-porous bridges for the coolant between the rows of capillary-porous columns, made with an arbitrary step.

The claimed technical solution is illustrated by figures 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12.

In FIG. 1 shows the design of the inventive metal heat pipe of a flat type with a spatial cellular structure formed by capillary-porous columns, for example, round.

In FIG. 2 option of the claimed design of a metal heat pipe of a flat type with a spatial cellular structure formed by capillary-porous columns with an arbitrary shape.

In FIG. 3 is a variant of the inventive metal heat pipe of a flat type with a spatial cellular structure, on the inner surfaces of the walls of the body of which channels-arteries for the coolant are made.

In FIG. 4 is a variant of the claimed design of a flat type metal heat pipe with a spatial cellular structure on the inner side of the upper and lower capillary - porous wicks, which have steam channels arranged, for example, with an arbitrary step between the rows of capillary-porous columns.

In FIG. 5 is a variant of the claimed design of a flat type metal heat pipe with a spatial cellular structure with steam channels between the rows of capillary-porous columns and artery channels for the coolant on the inner surfaces of the housing walls.

In FIG. 6 is a variant of the claimed design of a flat type metal heat pipe with a spatial cellular structure with porous arteries for the coolant in the form of capillary-porous rectilinear bridges located at an arbitrary step between the capillary-porous columns.

In FIG. 7 is a variant of the claimed design of a flat type metal heat pipe with a spatial cellular structure with capillary-porous columns alternating with capillary-porous arteries for the coolant in the form of rectilinear porous bridges, and ducts-arteries for the coolant on the inner surfaces of the housing walls.

In FIG. 8 is a variant of the claimed design of a flat type metal heat pipe with a spatial cellular structure and with porous arteries for the coolant in the form of rectilinear porous bridges, ducts-arteries for the coolant on the inner surfaces of the walls of the casing and steam channels between the rows of capillary-porous columns.

In FIG. 9 is a fragment of the internal structure of a flat type heat pipe of the claimed design with a spatial cellular structure formed by capillary-porous columns, for example, round.

In FIG. 10 is a fragment of the internal structure of a flat type heat pipe of the claimed design with a spatial cellular structure formed by capillary-porous columns, for example, round and with porous arteries for the coolant in the form of capillary-porous rectilinear bridges.

In FIG. 11 - the location of the heat pipe of the claimed design and temperature sensors in the example of a specific implementation.

In FIG. 12 is a table comparing the characteristics of options for metal heat pipes of the claimed design.

The inventive flat heat pipe (Fig. 1) consists of a casing representing the upper (1) and lower (2) metal plates, with the upper capillary-porous wick (3) and the lower capillary-porous wick deposited on their inner sides, respectively (four). Between the walls of the casing (1 and 2), a space is formed in which there are rows of capillary-porous columns (5) of arbitrary cross section, for example, as shown in the round figure, with the ends of the capillary-porous columns (5) in contact with capillary-porous wicks (3 and 4) the walls of the housing.

The coolant is supplied to the heat pipe evaporation zone due to the system of capillary-porous coolant channels formed by the upper (3) and lower (4) capillary-porous wicks on the inner surfaces of the body and the rows of capillary-porous columns (5) in contact with them (5) .

In addition, this design forms a spatial cellular structure of a system of steam drainage channels located between the outer surface (6) of the upper (3) capillary-porous wick and the outer surface (7) of the lower (4) wick of the housing surfaces and the walls (8) of the columns.

In FIG. 2 shows a variant of the claimed design of a flat type heat pipe with an arbitrary shape of columns, for example, oval (9). The use of this form of columns allows you to improve not only the strength characteristics of the heat pipe, but also the aerodynamics of the steam flow, and in addition, the volume of capillary-porous coolant channels increases.

In FIG. 3 shows a variant of the inventive heat pipe on the inner surfaces of the upper (1) and lower (2) body plates of which are made the artery channels (10) for the coolant, the length of which, for example, may not coincide with the length of the heat pipe in order to equalize the pressure over the heat pipes.

The presence of artery channels (10) for the coolant allows to increase the flow of coolant to the upper (3) and lower (4) capillary-porous wicks located respectively on the upper (1) and lower (2) plates of the body.

In FIG. 4 is a variant of the claimed design of a flat type heat pipe on the inner side of the upper (3) and lower (4) capillary-porous wicks, which have steam channels (11) located at an arbitrary step between the rows of capillary-porous columns (5). The presence of steam drainage channels (11) allows one to create the direction of steam movement with the lowest aerodynamic drag, and on the other hand, reduces the thickness of the upper and lower capillary-porous wicks, thereby reducing their thermal resistance. In addition, the vapor channels (11) allow you to increase the evaporation area by increasing the area of the side walls.

In FIG. 5 shows a variant of the inventive heat pipe on the inner surfaces of the upper (1) and lower (2) plates of the body of which are made the artery channels (10) for the coolant, and on the inner sides of the upper (3) and lower (4) capillary-porous wicks, steam channels (11) located with an arbitrary step between the rows of capillary-porous columns (5).

The presence of artery channels (10) for the coolant can further increase the flow of coolant to the upper (3) and lower (4) capillary-porous wicks located respectively on the upper (1) and lower (2) plates of the body.

In FIG. 6 shows a variant of the claimed design of a heat pipe with capillary-porous arteries for the coolant in the form of rectilinear porous bridges (12) located at an arbitrary step between the capillary-porous columns (5). Rectilinear porous bridges (12) and capillary-porous columns (5) are adjacent to the upper (3) and lower (4) capillary-porous wicks.

The presence of porous arteries for the coolant in the form of rectilinear capillary-porous bridges (12) allows to increase the structural strength of the heat pipe and increase the flow of the heat carrier supplied to the evaporation zone of the heat pipe.

In FIG. 7 shows a variant of the claimed design of a heat pipe with capillary-porous arteries for the coolant in the form of rectilinear porous bridges (12) located at an arbitrary step between the capillary-porous columns (5) in contact with the upper (3) and lower (4) capillary-porous wicks, and on the inner surfaces of the upper (1) and lower (2) walls of the body there are artery channels (10) for the coolant.

In FIG. 8 shows a variant of the claimed design of a heat pipe with porous arteries for the coolant (12) in the form of rectilinear parallel capillary-porous bridges in contact with the upper (3) and lower (4) capillary-porous wicks and located at an arbitrary step between the capillary-porous columns ( 5), moreover, on the inner surfaces of the upper (1) and lower (2) plates of the casing, artery channels (10) for the coolant are made, and on the inner sides of the upper (3) and lower (4) capillary-porous wicks, steam channels (11 ) split conjugated with an arbitrary pitch between rows of capillary-porous columns (5).

Embodiments of a flat type heat pipe of the claimed design described above depend on the tasks that are set during its operation, for example, on the temperature of the surface to be cooled, on the choice of the structural material of the heat pipe, on the choice of coolant, on the geometry of the heat pipe.

In FIG. 9 shows a fragment of the inner part of a heat pipe of a flat type of the claimed design with a spatial cellular structure formed by rows of capillary-porous columns (5), for example, round.

In FIG. 10 shows a fragment of the inner part of a flat type heat pipe of the inventive heat pipe with a spatial cellular structure formed by rows of capillary-porous columns (5), for example, round and with porous arteries for the coolant in the form of capillary-porous rectilinear bridges (12).

The inventive heat pipe flat type operates as follows. The supply of heat from a heated source to the evaporation zone of the heat pipe occurs through the upper (1) and lower (2), for example, the metal walls of the casing (Fig. 1). The coolant is supplied to the heat pipe evaporation zone due to the system of porous coolant channels formed by the upper (3) and lower (4) capillary-porous wicks on the inner surfaces of the casing and the capillary-porous columns in contact with them (5).

A change in temperature leads to a nonequilibrium state of the system, which leads to the appearance of a pressure differential between the hot and cold zones of the heat pipe and the steam begins to move from the warmer zone (high pressure zone) to the colder zone (low pressure zone). Due to the pressure difference, the steam moves and the heat source cools. Through the pores of the coolant channels, the heated coolant also evaporates through steam channels (11) formed by the outer surface (6) of the upper capillary-porous wick (3), the outer surface (7) of the lower capillary-porous wick (4) and the walls (8) capillary -porous columns (5), passes into the condensation zone of the heat pipe.

In FIG. 9 shows a fragment of the internal structure of a heat pipe of a flat type of the claimed design with a spatial cellular structure formed by rows of capillary-porous columns (5), for example, round.

In FIG. 10 shows a fragment of the internal structure of the inventive heat pipe with a spatial cellular structure formed by capillary-porous columns (5), for example, round and with porous arteries for the coolant in the form of capillary-porous rectilinear bridges (12).

For the upper and lower metal plates of the inventive heat pipe, various materials can be used, for example, copper, nickel, titanium, stainless steel and so on. Capillary-porous wicks of the walls of the heat pipe body and capillary-porous columns are formed from similar pressed and sintered powders. As a heat carrier, for example, water, alcohol, acetone, acetonitrile, etc., as in any heat pipe can be used. The sides of the casing of a flat heat pipe are connected to each other and to the capillary-porous structure of the upper and lower wicks and capillary-porous columns using powder metallurgy methods (pressing, sintering, diffusion or thermal diffusion welding, etc.).

As examples of the specific implementation of the claimed technical solution, the following samples of metal heat pipes of a flat type of the claimed design are made according to one technological regime.

Flat type metal heat pipe sample No. 1 is a heat pipe with a spatial cellular structure formed by rows of capillary-porous columns (Fig. 1).

Flat type metal heat pipe sample No. 2 is a variant of a heat pipe with a spatial cellular structure formed by rows of capillary-porous columns and two porous arteries for the coolant in the form of rectilinear bridges (Fig. 6).

A flat type metal heat pipe sample No. 3 is a heat pipe option with a spatial cellular structure formed by rows of capillary-porous columns and four porous arteries for the coolant in the form of rectilinear bridges (Fig. 6).

Their upper and lower metal plates were made of copper tape of the DPRNT M103 × 300 brand (GOST 1173-2006) [6] 0.3 mm thick, the upper and lower capillary-porous wicks and capillary-porous columns of PMS-1 copper powder (GOST 4060-75) [7], and the thickness of the capillary-porous wicks ranged from 0.5 to 0.7 mm, and the height of the capillary-porous columns from 1 to 1.5 mm.

The tests were carried out at a thermostat coolant temperature of 20 ° C, at various thermal powers emitted by the heater (from 0 to 150 W). The test product was located on the edge at an angle of 25 ° (Fig. 11) relative to the horizon. Water was used as a heat carrier.

The temperature sensor T1 was installed on the heater substrate, the sensor T2 was installed under the heat pipe cooler and measured the temperature of the tested metal heat pipe, the sensor T3 was installed on the surface of the metal heat pipe of the claimed design from the opposite side of the heater.

The results for comparing the operation of metal heat pipes of a flat type of the claimed design are shown in table 1 "Comparison of the characteristics of metal heat pipes of a flat type of the claimed design" (Fig. 12).

As can be seen from the data given in the table, the larger the cross-sectional area of the liquid (heat-transferring) channels, the greater the working load can withstand the metal flat heat pipe of the claimed design.

The spatial cellular structure of the claimed design of a metal heat pipe may contain continuous capillary-porous rectilinear bridges, the number of which can vary and which can be located along the pipe area from the places of increased local heating to the place of heat removal, which provides increased thermophysical characteristics with uneven heating over the area of the heat pipe and equalization of the general temperature field.

The heat pipes of the claimed design demonstrate an approximation to the optimal ratios of the area of the heat-carrying and steam channels with a fixed value of the characteristics of the porous structure of the porous arteries of the coolant and capillary-porous columns.

The increase in effective thermal conductivity of the claimed design of a flat type heat pipe at high specific heat loads is due to the presence of additional wicks for the coolant in its design.

A metal heat pipe of a flat type of the claimed design is also operable under conditions when the transfer of the working fluid is carried out in the opposite direction to the action of gravity.

In addition, the inventive design of a metal heat pipe of a flat type allows the use, for example, of low-temperature boiling fluids to provide high tensile strength from internal pressure.

The use of the heat pipe of the proposed design is promising in aircraft, including in space technology.

Used sources.

1. USSR copyright certificate No. 1673824.

2. RF patent for the invention No. 2457417.

3. US patent No. 8356657.

4. US Patent No. 9459050.

5. US patent No. 6293332.

6. GOST 1173-2006 “Foil, tapes, sheets and plates of copper. Technical conditions. "

7. GOST 4960-2009 “Electrolytic copper powder. Technical conditions. "

Claims (8)

1. A metal heat pipe of a flat type, including a housing with an evaporation, transport and condenser zones, a coolant supply system, a capillary-porous wick formed on the inner surface of the opposite walls of the housing with the formation of a gap in its central part, in which a system of steam drainage channels is located, characterized the fact that the coolant is supplied to the evaporation zone of the heat pipe through a system of porous channels for the coolant, consisting of upper and lower capillary-por wicks on the inner surfaces of the casing and rows of capillary-porous columns of arbitrary cross-section located between them, and the system of steam drainage channels is a spatial cellular structure formed between the outer surfaces of the upper and lower capillary-porous wicks of the casing surfaces and the walls of the capillary-porous columns, and the volume of the heat pipe and the steam volume is in the range from 0.5: 1 to 4.0: 1. 2. A metal heat pipe of a flat type according to claim 1, characterized in that the capillary-porous columns in the cross section are made round. 3. A flat type metal heat pipe according to claim 1, characterized in that the capillary-porous columns in the section are oval. 4. A metal heat pipe of a flat type according to claim 1, characterized in that on the inner surfaces of the body channels-arteries are made for the coolant. 5. A metal heat pipe of a flat type according to claim 1, characterized in that on the inner side of the upper and lower capillary-porous wicks adjacent to the inner surfaces of the casing, vapor channels are made between rows of capillary-porous columns. 6. A flat type metal heat pipe according to claim 1, characterized in that between the upper and lower capillary-porous wicks of the housing surfaces arteries are made for the coolant in the form of capillary-porous rectilinear bridges alternating with capillary-porous columns. 7. A metal heat pipe of a flat type according to claim 1, characterized in that on the inner surfaces of the housing there are made artery channels for the coolant, and arteries for the coolant are made in the form of capillary-porous rectilinear bridges alternating with upper and lower capillary-porous wicks capillary-porous columns. 8. A metal heat pipe of a flat type according to claim 1, characterized in that on the inner surfaces of the casing the artery channels are made for the coolant, arteries for the coolant are made in the form of capillary-porous straight bridges alternating with capillary between the upper and lower capillary-porous wicks -porous columns, and on the inner side of the upper and lower wicks adjacent to the inner surfaces of the body, vapor channels are made between rows of capillary-porous columns and capillary-porous rectilinear jumpers.

Images