WO2023187920A1

WO2023187920A1 - Dew condensation drainage recovery device and cooling device

Info

Publication number: WO2023187920A1
Application number: PCT/JP2022/015096
Authority: WO
Inventors: 孔一轟; 実吉川; 善則宮本; 隆大塚; 信夫金子
Original assignee: 日本電気株式会社
Priority date: 2022-03-28
Filing date: 2022-03-28
Publication date: 2023-10-05

Abstract

The present invention relates to a technology for preventing the mixing of water droplets into cooling air due to dew condensation generated in a local cooling device.　According to the present invention, a heat exchange device comprises a drainage receiving member (3) which receives drainage generated by cooling a cooling target (S) with a heat exchanger (2) and guides the drainage in a prescribed direction, the drainage receiving member (3) being provided at a position upstream from one side (C) of an air flow passage (1) which suctions the cooling target (S) from the other side H and discharges the cooling target toward the one side (C), and provided below the heat exchanger (2) which is disposed in an oblique manner with respect to the vertical direction. The drainage receiving member (3) is disposed at a position directly above a hot aisle of a server room.　

Description

Condensation drain recovery device and cooling device

The present invention relates to a condensation drain recovery device and a cooling device. In particular, the present invention relates to a condensation drain recovery device and a cooling device suitable for air conditioning equipment in data centers.

For cooling spaces such as server rooms in data centers that house a large number of electronic devices such as servers that generate heat, the process of receiving, compressing, releasing, and expanding the refrigerant causes the refrigerant that has received the heat of the heat source to be released into the atmosphere. A cooling device that uses a refrigeration cycle that releases heat is used.
In addition to being an air conditioner that maintains air conditioning for the entire server room, a cooling device that uses this refrigeration cycle absorbs heat from the electronic equipment (for example, a server rack in which multiple servers are stacked) and brings it into the room. It may also be used in local cooling systems where the exhausted air is immediately guided to a heat exchanger for cooling.

Since this local cooling device is installed very close to electronic equipment such as servers, it is necessary to reliably remove drains caused by condensation that can cause malfunctions of electronic equipment, and to prevent the drain from being sucked into electronic equipment. consideration is required.
Patent Document 1 related to the present invention discloses that in order to adjust the temperature and humidity inside the server room to an appropriate level, drain caused by condensation on a heat exchanger is collected and used to adjust the humidity of air supplied to the server room. The technology has been disclosed.
Patent Document 2 related to the present invention discloses a technique for controlling a cooling device so that air sucked into the cooling device (exhaust air from a server) does not fall below the dew point.
Patent Document 3 related to the present invention discloses a technique of providing a drain pan between a heat exchanger and an air filter.
Patent Document 4 related to the present invention discloses a configuration in which a filter is provided below an evaporator.
Patent Document 5 related to the present invention discloses a structure in which a moisture absorbent is immersed in a drain pan.
Patent Document 6 related to the present invention discloses a configuration in which a filter is provided below the cooler and a drain pan is further provided below the filter.

Japanese Patent Application Publication No. 2010-133618 Japanese Patent Application Publication No. 2003-130430 Japanese Patent Application Publication No. 6-347055 Japanese Patent Application Publication No. 2002-333237 Japanese Patent Application Publication No. 2004-176999 Utility Model Publication No. 58-11624

However, Patent Document 1 merely discloses a configuration for collecting water droplets generated due to dew condensation, and prevents drains due to condensation from being sucked into electronic devices such as servers in local cooling of the server room. No specific measures have been disclosed.
Furthermore, Patent Document 2 discloses a configuration that prevents dew condensation by maintaining a temperature above the dew point by controlling the temperature of a heat exchanger, but since the cooling device is controlled with priority given to preventing dew condensation, , for example in high humidity climatic conditions, cooling of the server may be insufficient.
Moreover, the above Patent Documents 3 to 6 merely disclose a configuration in which drain is received by a filter provided close to equipment where condensation occurs, such as a general heat exchanger, and the drain is collected in a drain pan. , does not disclose a specific configuration of how to collect drain in a local cooling device of a server room and prevent condensed drain from being mixed into cooling air.

The purpose of this invention is to prevent condensation drain generated in a heat exchanger from being mixed into cooling air.

In order to solve the above problems, the present invention proposes the following means.
This condensation drain recovery device is disposed at a position upstream of the other side of the air flow path where the air is sucked from one side of the object to be cooled and discharged to the other side, and is oriented diagonally with respect to the vertical direction. a drain receiving member provided below the heat exchanger to receive condensation drain generated by cooling by the heat exchanger and guide it in a predetermined direction;
The object to be cooled is a server rack storing servers, and the drain receiving member is disposed directly above a passage in a server room through which cooling air that has passed through the server rack is discharged. .

According to the present invention, water droplets generated in the heat exchanger due to dew condensation can be prevented from being mixed into the cooling air.

1 is a sectional view of a condensation drain recovery device according to a minimum configuration example of the present invention. FIG. 2 is a cross-sectional view showing an example of the arrangement of a heat exchange device including a condensation drain recovery device according to an embodiment of the present invention with respect to a cooling target. FIG. 3 is a sectional view showing details of the heat exchange device portion of FIG. 2; FIG. 4 is a plan view of the drain pan of FIG. 3;

An example of the minimum configuration of a heat exchanger equipped with a condensation drain recovery device according to the present invention will be described with reference to FIG.
This heat exchange device is installed at a position on the upstream side of the other side C of the air flow path 1 that sucks air from one side H of the object to be cooled S and discharges it to the other side C. A drain receiving member 3 is provided below the heat exchanger 2 arranged to face the server, and receives drain caused by condensation generated by cooling by the heat exchanger 2 and guides it in a predetermined direction.The object to be cooled is a server. In the stored server rack, the drain receiving member is disposed directly above a passage in the server room through which cooling air that has passed through the server rack is discharged.

According to the heat exchange device according to the present invention configured as described above, when dew condensation occurs on the heat exchanger 2 due to heat exchange with air and water droplets due to this condensation fall downward, Water droplets can be received in the drain receiving member 3 and guided in a predetermined direction from the drain receiving member 3, and, for example, it is possible to prevent the water droplets from falling to the other side C of the object to be cooled. Further, since the drain receiving member 3 is disposed above the so-called hot aisle side in the server room, it is possible to suppress the phenomenon that the collected drain is sucked into the server rack.

An embodiment of the present invention that embodies FIG. 1 will be described with reference to FIGS. 2 to 4.
With reference to FIG. 2, a configuration example of a heat exchange device including a condensation drain recovery device according to an embodiment will be described.
FIG. 2 shows an example of the arrangement of the heat exchanger 20.
The cooling target S is, for example, a rack in which a plurality of servers are stacked one on top of the other, and a fan F1 installed in each server sucks air from a cold aisle in the server room as shown by arrow A into an arrow B. , C, the inside of the server, which is the object to be cooled, is cooled by being guided and discharged to the hot aisle H as shown by arrow D, and sucked again by the fan F1 as shown by arrow D.
A duct 10 constituting a local cooling device is provided above the object S to be cooled. This duct 10 opens downward on the hot aisle H side and the cold aisle C side, and includes a fan F2 in the opening on the hot aisle H side that sucks air into the duct 10 as shown by arrow A.

The heat exchanger 20 has, for example, a configuration in which a large number of heat exchange pipes through which a refrigerant flows are arranged in parallel in one plane (or a single heat exchange pipe is bent many times), and the surface of the heat exchange pipe is is equipped with radiation fins (not shown) to ensure a large contact area with the air.
The heat exchanger 20 is provided, for example, above the opening on the inlet side of the duct 10 so as to be inclined with respect to the vertical direction.
In addition, the heat exchanger 20 is configured such that the refrigerant supply side (the side where the liquid phase refrigerant flows in) of the heat exchange pipe is directed downward, and the refrigerant discharge side (the side where the vapor phase refrigerant evaporated by heat reception is discharged) is directed upward. It is placed diagonally towards.

The configuration of the condensation drain recovery device will be explained with reference to FIGS. 3 and 4.
The receiving member 30 constituting the condensation drain recovery device is arranged below the heat exchanger 20 in parallel (with the same inclination) as the heat exchanger 20.
As shown in FIG. 4, the receiving member 30 has an outer shape that substantially matches that of the heat exchanger 20, and has a structure in which a mesh portion 32 made of a large number of wire rods is provided inside a frame 31.
The mesh portion 32 has a structure in which, for example, metal wires coated with fluororesin are stretched vertically and horizontally, and the distance between the wires is, for example, equal to or smaller than the distance between the heat radiation fins of the heat exchanger 20.

That is, in the heat exchanger 20, since dew condensation generally occurs between the radiation fins, there is a high probability that the size of water droplets falling from between the radiation fins will be larger than the gap between the radiation fins. In consideration of this phenomenon, the spacing between the wire rods constituting the mesh portion 32 is set to be equal to or smaller than the mutual spacing between the radiation fins. Furthermore, by applying a water-repellent finish to the wire rod, it is possible to prevent the water droplets from passing through the mesh portion 32, so that the water droplets that have fallen onto the surface of the receiving member 30 can be guided downward in an inclined manner. Moreover, since the receiving member 30 is made of a wire rod, the adverse effect of interfering with the airflow flowing through the duct 10 is suppressed to a minimum.

A temporary storage section 40 is disposed at the lower end of the receiving member 30 to collect drain flowing along the slope of the receiving member 30. The temporary storage section 40 has a gutter-like structure having a width approximately equal to that of the receiving member 30 (dimension in the direction perpendicular to the paper surface of FIG. 2), and collects drains that have fallen down along the receiving member 30. A predetermined amount can be accepted.
That is, since the condensation that occurs in the heat exchanger 20 often occurs temporarily depending on the weather conditions, the temperature and humidity of the server room, etc., the condensation that occurs temporarily can be drained as much as possible. It is sufficient to have sufficient capacity to store. Moreover, by employing a drainage mechanism described later as necessary, the capacity can be further reduced and the size can be reduced.

Further, the temporary storage section 40 is provided with a drain vaporization member 41.
The drain vaporizing member 41 is made of, for example, a porous material, a fibrous material, or other material that has the ability to suck drain through capillary action and has air permeability.
The drain vaporization member 41 is disposed so that its lower end contacts the temporary storage section 40 and crosses the duct 10 (extending in a direction perpendicular to the paper plane of FIG. 3).
The drain vaporizing member 41 configured in this manner can suck up the drain accumulated in the temporary storage section 40 by capillary action, diffuse it over the entire surface, and evaporate it into cooling air by contact with the airflow flowing through the duct 10. Furthermore, since it is made of a porous material or a fibrous material, resistance to the airflow flowing inside the duct 10 can be minimized. Note that the width dimension of the drain evaporating member 41 (the dimension in the direction perpendicular to the plane of the paper in FIG. 3) does not need to be the entire width of the duct 10, and depends on the conditions of the amount of condensation drain to be evaporated and the flow rate of air, or, For example, the width may overlap with only a part of the cross section of the duct 10, depending on the flow path resistance conditions allowed for the duct 10.

In the heat exchanger configured as described above, the air discharged from the object to be cooled S to the hot aisle H rises as shown by arrow A (because the temperature is higher than room temperature) and is sucked by fan F2. and guided into the duct 10.
The air guided into the duct 10 passes through the mesh portion 32 constituting the drain receiving member 30 and passes through the heat exchanger 20, and as it passes through, the refrigerant flowing through the refrigerant piping of the heat exchanger 20 is evaporated. It flows through the duct 10 as shown by arrow B and is released to the cold aisle C side as shown by arrow C.

If the temperature of the refrigerant flowing through the heat exchanger 20 is below the dew point depending on the climate conditions (temperature and humidity conditions), the air cooled by the heat exchanger 20 may be cooled by the heat exchange pipes and radiation fins of the heat exchanger 20. Condensation forms on the surface and falls downward as water droplets.
The water droplets falling downward do not pass through the mesh part 32 and are absorbed by the drain receiving member 30 because the distance between the wire rods of the mesh part 32 constituting the drain receiving member 30 is smaller than the water droplets and has water repellency. It flows downward along the slope and flows into the temporary storage section 40 . In one embodiment, the drain receiving member 30 is inclined along the heat exchanger 20, so that the distance of water droplets falling from the heat exchanger 20 is minimized, so that the water droplets do not fall onto the mesh portion 32. There is a small possibility that water droplets will pass through the mesh portion 32 due to impact.

Further, since the lower end of the drain vaporizing member 41 is disposed in the temporary storage section 40, the drain vaporizing member 41 immersed in the stored condensation drain sucks up the condensation drain by capillary action, and the entire drain vaporizes. spread to. In addition, since the drain vaporizing member 41 is porous or fibrous, it ensures a large contact area between the sucked up condensation drain and the airflow in the duct 11, thereby preventing evaporation and diffusion of the condensation drain into the airflow. can be promoted.

The arrangement of the heat exchanger 20 and the drain receiving member 30 is not limited to the bent portion of the duct 10 shown by the solid line in FIG. 2, but may be placed in the straight pipe portion of the duct 10 shown by the chain line in FIG. .
Discharge of the condensation drain stored in the temporary storage section 40 is not limited to the configuration using the drain vaporization member 41, but may also include a configuration in which the condensation drain is discharged outside the cooling air circulation system using a pump or the like, or a duct. It is desirable to select an optimal configuration, such as a configuration in which condensation is diffused on the bottom surface of the straight pipe section 10, in consideration of the amount of condensation drain generated (the amount of condensation drain that should be evaporated) and the installation and maintenance cost of the cooling system. Furthermore, if a water gradient is provided on the bottom of the straight pipe part of the duct 10 so that it slopes downward to the right in FIG. It is possible to prevent the water droplets from being sucked into the server from the cold aisle C side again.

The arrangement of the heat exchanger 20 and the drain receiving member 30 is not limited to the one embodiment described above, but any arrangement other than the opening on the exit side of the duct 10 (the position directly above the cold aisle C) may be used. Even if there are water droplets that cannot be collected, the possibility that these water droplets will be sucked into the server can be reduced.
The water repellency possessed by the mesh portion 32 of the drain receiving member 30 is a phenomenon that occurs when the surface tension of the solid surface is lower than the surface tension of the liquid. This can also be achieved by surface treatment of the wire and material selection.

Moreover, instead of the mesh-like drain receiving member, a striped drain receiving member may be used in which a large number of water-repellent rod-like bodies (or linear bodies) are arranged in parallel in one direction. By having a striped configuration, it is possible to suppress an increase in flow path resistance due to occurrence of clogging peculiar to meshes.
The hygroscopic fibers used in the drain vaporization member include, for example, inherently hydrophobic fibers such as polyester or polypropylene, and hydrophilic fibers such as cellulose fibers such as cotton and viscose rayon. Although a mixture of hygroscopic fibers and hygroscopic fibers is preferably used, cloth or nonwoven fabric made of fibers other than these hygroscopic fibers, or porous materials having water absorbing properties may also be used.

Although the embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like may be made without departing from the gist of the present invention.

The present invention can be used in cooling devices employed in air conditioners and the like, particularly in recovering condensation drains thereof.

1 (Air)

channel

2, 20 Heat exchanger 3 Drain receiving member 10 Duct 30 Drain receiving member 31 Frame 32 Mesh portion 40 Temporary storage portion 41 Drain vaporization member

Claims

It is installed below a heat exchanger that is arranged diagonally to the vertical direction in the flow path of air that is sucked in from one side of the object to be cooled and discharged to the other side, and the heat exchanger cools the object. It is equipped with a drain receiving member that receives the condensation drain generated by the drain and guides it in a predetermined direction.
The object to be cooled is a server rack storing servers, and the drain receiving member is disposed directly above a passage in a server room from which cooling air that has passed through the server rack is discharged.
Condensation drain recovery device.
The drain recovery device according to claim 1, wherein the drain receiving member is arranged obliquely along the heat exchanger.
The drain receiving member is composed of a plurality of linear bodies arranged at predetermined intervals.
The condensation drain recovery device according to claim 1 or 2.
The distance between the linear bodies constituting the drain receiving member is smaller than the water droplets formed by the drain generated in the heat exchanger.
The condensation drain recovery device according to claim 3.
A drain storage portion is provided near the lower end of the drain receiving member to receive the drain flowing along the drain receiving member.
The condensation drain recovery device according to any one of claims 1 to 4.
The drain storage section includes a drain discharge section that discharges the drain stored in the drain storage section.
The condensation drain recovery device according to claim 5.
The drain discharge part guides drain absorbed from the drain to a flow path downstream of the heat exchanger.
The condensation drain recovery device according to claim 6.
The drain discharge part is a fibrous material or a porous material that absorbs drain from the drain storage part by capillary action and evaporates into the flow path.
The condensation drain recovery device according to claim 6 or 7.
The object to be cooled is an electronic device including a fan that sucks air from the other side and discharges air that has absorbed internal heat to the one side, and the drain discharge section is located downstream of the heat exchanger. evaporating the drain into air flowing through a side channel;
The condensation drain recovery device according to any one of claims 6 to 8.
The condensation drain recovery device according to any one of claims 1 to 9,
a heat exchanger disposed above the drain receiving member of the condensation drain recovery device;
A cooling device with