KR102037492B1 - Heatpipe with outside wicks - Google Patents

Abstract

The present invention relates to an external wick heat pipe and, more specifically, to an external wick heat pipe which enables a plurality of grooves to be formed outside the heat pipe to increase thermal transfer effects. According to the present invention, the external wick heat pipe comprises: a cylindrical pipe body; and a plurality of wick grooves formed outside the pipe body in parallel to the longitudinal direction of the pipe body.

Description

Heatpipe with outside wicks}

The present invention relates to an external wick heat pipe, and more particularly, to an external wick heat pipe capable of improving a heat transfer effect by forming a plurality of grooves outside the heat pipe.

Generally, the heat pipe is vacuum exhaust after injecting the working fluid into the hollow metal pipe, and when one end is heated, the working fluid inside is vaporized, moved to the other side by the pressure difference, and heat is released to the surrounding area. Through the condensation process, it is operated continuously by returning to the heating part.

In addition, in order to efficiently return the working fluid of the liquid returned after heat dissipation by capillary action as described above, a relatively dense and thin mesh, a fine groove or a sintered metal powder is attached to the inner wall of the metal pipe. Many types of heat pipes in which the working fluid is injected into the pipes are used.

On the other hand, servers, network equipment, enterprise equipment and the like provided in the data center generates heat. As a result, the data centers operating these devices also operate large-scale facilities to cool the heat.

Servers are usually located in racks in the data center. Physical configurations for racks vary. Typical rack configurations include mounting rails, which are equipped with multiple equipment units, such as server blades, stacked vertically inside a rack. One of the most widely used 19-inch racks is a standard system for mounting equipment such as 1U or 2U servers. One rack unit on this type of rack is 175 inches high and 19 inches wide. Rack-Mounted Unit (RMU) servers that can be installed in one rack unit are commonly referred to as 1U servers. In data centers, standard racks are typically densely populated with servers, storage devices, switches and / or communications equipment. In some data centers, fanless RMU servers are used to increase density and reduce noise.

The data center room should be kept at an acceptable temperature and humidity for reliable operation of servers, especially servers without fans. Racks with densely stacked servers powered by Opteron or Xeon processors can range from 7,000 to 15,000 watts. As a result, server racks can produce very concentrated heat loads. Heat lost by the servers in the rack is exhausted into the data center room. The heat generated collectively by densely arranged racks depends on the ambient air for cooling and can adversely affect the performance and reliability of the equipment in the racks. Thus, heating, ventilation, and air conditioning (HAVC) systems are an important part of the design of an efficient data center.

Republic of Korea Utility Model Registration No. 20-0288903 (2002.09.11.) Republic of Korea Patent Publication No. 10-2005-0093959 (2005.09.26.) Republic of Korea Utility Model Registration Publication No. 20-0479829 (2016.03.10.)

It is an object of the present invention to provide an external wick heat pipe having excellent heat transfer performance and efficiency in order to effectively cool a server in a data center.

In order to achieve the above object, the outer wick heat pipe of the present invention comprises a cylindrical pipe body and a plurality of wick grooves formed parallel to the longitudinal direction of the pipe body on the outside of the pipe body.

In addition, a nano heat dissipation coating layer is formed on the outside of the pipe body, and the nano heat dissipation coating layer has 95% by weight of graphene, 2% by weight of polyurethane, 1% by weight of acrylate, and 2 Consisting of weight percent unavoidable impurities.

The nano heat-dissipating coating layer is formed in a thickness of 5 ~ 15㎛ on the pipe body, and dried at 80 ℃ for 30 minutes or more and fixed to the pipe body surface.

The heat pipe may include a first accommodating part in which a working fluid is accommodated as a sealed space, and a second accommodating part which is open at one end connected to the cooling pipe and extends in the other end direction. A part is formed to surround the second accommodating part, and the second accommodating part has a cooling water flowing along the cooling pipe to allow heat transfer between the working fluid and the cooling water.

The external wick heat pipe of the present invention may increase the surface area for heat transfer with the heating air and reduce the rising speed of the heating air to increase the contact time with the heating air, thereby improving heat transfer performance and efficiency. have.

The non-powered cooling system using the external wick heat pipe of the present invention effectively absorbs heat by using the natural convection of the air heated by heat generated from the server without a separate power source for forced convection of air around the server, thereby cooling the server. Can be maximized.

1 is a view schematically showing a non-powered cooling system using an external wick heat pipe according to an embodiment of the present invention.
Figure 2 is a perspective view of a heat pipe non-powered cooling system except the cooling water supply.
3 is a perspective view of a heat pipe according to a first embodiment of the present invention.
4 is a cross-sectional view of a heat pipe according to a first embodiment of the present invention.
5 is a cross-sectional view illustrating an internal structure of an external wick heat pipe according to a second embodiment of the present invention.

Hereinafter, an external wick heat pipe according to each embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First embodiment

The external wick heat pipe 200 according to the first embodiment of the present invention includes a pipe body 200a and a plurality of wick grooves 201 as shown in FIGS. 3 to 4.

The pipe body 200a is formed in a cylindrical shape. And the working fluid is accommodated inside the pipe body (200a). The space in which the working fluid is accommodated consists of a closed space. A plurality of wick grooves 201 are formed outside the pipe main body 200a in parallel with the longitudinal direction of the pipe main body 200a.

In the present invention, the wick groove 201 is formed outside the pipe main body 200a to increase the surface area for heat transfer with the heating air. In addition, by forming the wick groove 201 on the outside of the pipe body (200a) by increasing the friction with the heating air passing through the surface of the pipe body (200a) to reduce the moving speed of the heating air and the contact of the heat pipe 200 and air You can increase the time.

The working fluid accommodated in the pipe main body 200a is 41 to 46 parts by weight of acetone, 20 to 30 parts by weight of alcohol, 5 to 10 parts by weight of sulfuric ether, and 1,2-propylene. It comprises 5 to 10 parts by weight of glycol (1,2-propylene glycol; HOCH2CH3CHOH). In addition, the working fluid is 0.00035 to 0.00045 kg of methyl benzotriazole (5-methtlbenzole; C7H7N3) and sodium tripolyphosphate (Na5P3O10) based on 100 kg of acetone, alcohol, sulfulic ether, and 1,2-propylene glycol mixed solution. Contains 0.00028-0.00032 kg.

1,2-propylene glycol is mixed with distilled water and the ratio of the quantitative as described above has an excellent effect as a carrier for heat transfer and heat exchange. 1,2-propylene glycol is mixed with distilled water at freezing point of -60 ℃ to prevent the working fluid is frozen at the normal operating conditions or below (about -40 ℃). The working fluid may maintain a constant and stable internal pressure of the heat pipe 200 without causing a phase change at about −40 to 130 ° C. And methylbenzotriazole prevents corrosion of the heat pipe 200 as a corrosion inhibitor. And sodium tripolyphosphate to prevent foreign matter is formed on the inner peripheral surface of the heat pipe (200). If foreign matter is formed on the inner circumferential surface of the heat pipe 200, the endothermic effect is reduced.

Although the present invention preferably uses the above-described working fluid, a suitable working fluid may be used depending on the amount of heat released in the system (heating system requiring cooling, data center, etc.).

In addition, a nano heat dissipation coating layer may be formed on the outside of the pipe main body 200a. Specifically, the heat radiation coating layer is composed of 95% by weight of graphene, 2% by weight of polyurethane, 1% by weight of acrylate and 2% by weight of unavoidable impurities. Nano-radiation coating layer has excellent heat radiation and heat absorption to achieve effective heat transfer.

The nano heat dissipation coating layer is formed to have a thickness of 5 to 15 μm by cleanly cleaning the surface of the pipe body 200a and then applying a nano heat dissipation coating solution to the surface of the pipe body 200a. Thereafter, when dried at 80 ° C. or more for 30 minutes, the nano heat-dissipating coating layer is fixed to the surface of the pipe main body 200a.

Hereinafter, a non-powered cooling system using the external wick heat pipe of the present invention will be described.

The non-powered cooling system using the external wick heat pipe of the present invention includes a frame 100, a plurality of heat pipes 200, a cooling pipe 300, and a cooling water supply unit 400.

Frame 100 is installed above the server rack (R). As shown in FIG. 1, one frame 100 is installed on two server racks (R). Frame 100 is formed in a substantially rectangular pillar shape, a plurality of heat pipes 200 are installed therein. The size of the frame 100 may be changed according to the size of the server rack (R), the distance between the server rack (R), the number of heat pipes (200) installed.

The heat pipe 200 is installed in the frame 100, the working fluid is accommodated therein to absorb heat from the air rising to the top of the server rack (R). As illustrated in FIGS. 1 and 2, the plurality of heat pipes 200 are installed to cross between two server racks R. As illustrated in FIG. Accordingly, the heated air rises between the server and the server and passes between the plurality of heat pipes 200. At this time, heat transfer is performed between the heat pipe 200 and the heated air. As shown in FIG. 2, the plurality of heat pipes 200 are vertically connected to the cooling pipe 300.

The heat pipe 200 may be formed of several layers according to the required cooling performance. That is, since the heat pipe 200 is made up of several layers, the rising air may pass through more heat pipes 200, thereby performing heat transfer.

The heat pipe 200 may be provided with a cooling fin that can increase the surface area to the outside for effective heat transfer, in this case, the heat pipe 200 itself becomes smaller in size to accommodate the working fluid heat pipe 200 Inner space is reduced, or the number of heat pipes 200 that can be installed is bound to decrease.

On the other hand, the outer wick heat pipe 200 of the present invention is formed by the plurality of wick grooves 201 outside the pipe body 200a, thereby increasing the size of the heat pipe 200 itself in the same space or more heat pipe ( By installing the 200, it is possible to maximize the heat transfer effect by the heat pipe (200).

One end of each of the plurality of heat pipes 200 is connected to the cooling pipe 300 to absorb heat from the heat pipes 200. That is, one cooling pipe 300 is bent to be connected to one end of the plurality of heat pipes 200, respectively. One end of the heat pipe 200 is inserted into the cooling pipe 300 so that the cooling pipe 300 surrounds one end of the heat pipe 200. Accordingly, the working fluid absorbing the heat of the heating air in the heat pipe 200 transfers heat to the cooling water passing through the cooling pipe 300 at one end of the heat pipe 200.

The cooling water supply unit 400 circulates the cooling water to the cooling pipe 300.

As described above, when the surrounding air is heated by the heat generated by the server, the heating air rises and passes through the plurality of heat pipes 200. At this time, the heated air is heat transfer with the plurality of heat pipes (200). The working fluid contained in the heat pipe 200 absorbs heat from the heated air and then transfers heat back to the cooling water. This allows the working fluid to continuously absorb heat from the heated air. And the heat transfer air is introduced into the duct (D) is installed in the upper portion, and moves along the duct (D) and is discharged into the data center (C) through the outlet (E). On the other hand, by installing a fan in the discharge port (E) may be a smooth discharge of air to the data center (C).

Second embodiment

In the external wick heat pipe 200 according to the second embodiment of the present invention, as shown in FIG. 5, the first accommodating part 210 and the second accommodating part 220 are formed.

The first accommodating part 210 is formed as a closed space and a working fluid is accommodated therein. The second accommodating part 220 is open at one end connected to the cooling pipe 300 and extends in the other end direction.

The heat pipe 200 is formed such that the first accommodating part 210 surrounds the second accommodating part 220, and the coolant flows into the second accommodating part 220 to perform a working fluid and heat transfer. That is, the cooling water passing through the cooling pipe 300 flows into the second accommodating part 220, and the working fluid accommodated in the first accommodating part 210 surrounds the cooling water introduced into the second accommodating part 220 from the outside. It is in the form of heat transfer between the working fluid and the cooling water.

As in the first embodiment, the wick groove 201 and the nano heat dissipation coating layer may be formed outside the pipe main body 200a.

External wick heat pipe according to the present invention is not limited to the above embodiment can be carried out in a variety of modifications within the scope of the technical idea of the present invention.

100: frame,
200: heat pipe,
200a: pipe body,
201: Wickhome,
210: first accommodating part,
220: second receiving portion,
300: cooling pipe,
400: cooling water supply unit,
C: data center,
R: server rack,
D: duct,
E: outlet,

Claims (4)

A plurality of external wick heat pipe vertically connected to one cooling pipe passing through the cooling water, a plurality of wick grooves are formed outside the cylindrical pipe body in parallel with the longitudinal direction of the pipe body,
The pipe main body includes a first accommodating part in which a working fluid is accommodated as a sealed space, and a second accommodating part which is open at one end connected to the cooling pipe and extends in the other end direction.
The first accommodating part is formed to surround the second accommodating part, and cooling water flowing along the cooling pipe flows into the second accommodating part so that the working fluid surrounds the cooling water from the outside, between the working fluid and the cooling water. External wick heat pipe, characterized in that the heat transfer is made. The method according to claim 1,
The outer heat radiation coating layer is formed on the outside of the pipe body,
The nano-heat coating layer is an external wick heat, characterized in that consisting of 95% by weight of graphene (graphene), 2% by weight of polyurethane (polyurethana), 1% by weight of acrylate (acrylate) and 2% by weight of unavoidable impurities pipe. The method according to claim 2,
The nano heat-dissipating coating layer is formed in a thickness of 5 ~ 15㎛ on the pipe body, the outer wick heat pipe, characterized in that the dried to at least 30 minutes at 80 ℃ fixed to the pipe body surface. delete

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