Airflow mixing method for data center HVAC machine room

Abstract

This invention provides an airflow mixing method for a data center air conditioning machine room that promotes the mixing of return air and outside air, thereby suppressing the occurrence of short circuits between the return air and outside air, and making the intake temperature and flow rate of air to the air conditioner uniform, resulting in energy savings for the air conditioner. [Solution] In the air conditioning machine room 13, high-temperature return air a and low-temperature outside air c are mixed in the upper space on the other wall side 23, which is farther away from the air conditioner 12. This promotes the mixing of return air a and outside air c, suppresses the occurrence of short circuits in the return air a and outside air c, and makes it possible to equalize the intake temperature and flow rate of air to the air conditioner 12. As a result, energy savings can be achieved for the air conditioner 12.

Description

Technical Field

[0001] The present invention relates to an air flow mixing method for a data center air conditioning machine room, which mixes high-temperature return air from a server room and low-temperature outside air from the outside in an air conditioning machine room attached to the server room of the data center.

Background Art

[0002] In a data center such as the Internet, in order to remove heat generated from a large number of computers arranged in a rack shape in a server room and provide an environment in which the computers operate normally while maintaining a predetermined humidity, the air conditioner (chiller) in the air conditioning machine room attached to the server room operates throughout the year to perform cooling and humidity adjustment. However, since the computers in the server room generate a large amount of heat, the temperature of the return air (return air, RA) from the server room to the air conditioner is high. Therefore, in order to cool the return air to the set temperature and supply it as supply air (SA) to the server room, a large amount of power is consumed throughout the year.

[0003] Therefore, conventionally, in order to save energy by using outside air that is lower in temperature than the return air throughout the year, for example, an air conditioner for an outside air-cooled computer room described in Patent Document 1 is known. In this Patent Document 1, in the air conditioning machine room, high-temperature return air from a return air port that is previously in communication with the data room and outside air from an outside air port that is lower in temperature than this and in communication with the outside are mixed, and then this mixed air (MA) is sucked into the air conditioner, cooled to an appropriate temperature if necessary, and humidified, and then supplied as supply air to the server room. Thereby, the electric cost of the air conditioner can be reduced.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Disclosure of the Invention

[0005] However, when mixing return air and outside air in the air conditioning unit room, if the placement and orientation of the return air inlet and outside air inlet are not appropriate, a short circuit will occur where the return air and outside air are not mixed and are drawn into the air conditioner. When this short circuit occurs, the temperature and flow rate of the air drawn into the air conditioner will vary greatly depending on the position of the air conditioner's intake. This results in variations in the temperature difference and heat quantity with the air conditioner's heat exchanger, reducing the air conditioner's cooling capacity.

[0006] For example, if the inlet temperature of the heat exchanger of an air conditioner is 13°C for chilled water, and outside air with a temperature of 11°C partially enters the air conditioner without mixing with the return air through a short circuit, the purpose of cooling the mixed air with chilled water will instead be to partially heat the mixed air, leading to a decrease in the cooling capacity of the air conditioner.

[0007] As a result of diligent research, the inventor discovered that by guiding the return air that has passed through the return air inlet along the ceiling of the air conditioning machine room toward the other wall using a first airflow adjustment member, while directing the outside air that has passed through the outside air inlet upward along the other wall using a second airflow adjustment member, the above-mentioned problems can be resolved by mixing the return air and outside air in the upper space on the other wall side, far from the air conditioner's intake, within the air conditioning machine room, before the return air and outside air are drawn into the air conditioner. This led to the completion of the present invention.

[0008] This invention has been made in view of the above problems, and aims to provide an airflow mixing method for a data center air conditioning machine room that promotes mixing of return air and outside air, thereby suppressing the occurrence of short circuits between the return air and outside air, and making the intake temperature and flow rate of air to the air conditioner uniform, and as a result, saving energy for the air conditioner. [Means for solving the problem]

[0009] The invention described in claim 1 relates to an airflow mixing method for a data center air conditioning machine room, which is adjacent to the server room of the data center and houses an air conditioner that cools the high-temperature return air from the server room and supplies it to the server room, wherein the method mixes return air from the server room with outside air that is cooler than the return air from the outside, wherein a return air port for the return air returned from the server room is formed in the upper part of one wall of the air conditioning machine room, and the return air port is provided with a first airflow direction adjusting member that is inclined upward at 30° to 90° to guide the return air that has passed through the return air port along the ceiling of the air conditioning machine room toward the other wall, and the air conditioner is installed in the lower part of one wall of the air conditioning machine room below the return air port, and An air intake is formed at the lower part of the other wall facing one wall to allow outside air into the air conditioning machine room. The air intake is provided with a second airflow adjustment member that causes the outside air that has passed through the air intake to rise along the other wall. The return air that has passed through the return air intake is guided by the first airflow adjustment member along the ceiling of the air conditioning machine room toward the other wall, while the return air that has passed through the air intake is caused by the second airflow adjustment member to rise along the other wall. This method of mixing airflow in a data center air conditioning machine room is characterized by mixing the return air and the outside air in the upper space on the other wall side of the air conditioning machine room before they are drawn into the air conditioner.

[0010] The type of data center is arbitrary. For example, various cloud data centers are acceptable. The size, shape, and number of computers housed in a server room are arbitrary. Generally, a server room houses numerous computers arranged in racks. In addition, the room is divided into a cold aisle through which cooling air (supply air) passes and a hot aisle through which heated air (return air) passes. In this context, "return air" refers to the air heated by the heat generated by numerous computers in the server room, which is then returned from the server room to the air conditioning machine room.

[0011] While the air conditioning machinery room is generally located next to the server room, separated by a partition wall, it is not limited to this configuration. In this context, "one wall" refers to the wall in the air conditioning equipment room on the side where the air conditioners are installed (generally, the partition wall separating it from the server room). The type of air conditioner is arbitrary as long as it can cool, dehumidify, humidify, and mix the air (return air, outside air, etc.) in the air conditioning unit room with some of the return air as needed and supply it to the server room. The American Society of Heating, Refrigerating and Air-Conditioning Engineers recommends a dry-bulb temperature of 18-27°C, a relative humidity of 60% or less, and a dew point of 5.5-15°C for the air supplied to the server room. The number of air conditioners used is optional. One unit or two or more units are acceptable.

[0012] In this context, "the other wall" refers to the wall in the air conditioning machine room that faces the air conditioner (for example, the partition wall separating it from the outside). Here, "outside air" refers to air that is colder than the return air, such as the air outside. However, even if the outside air is colder than the return air, if the enthalpy of the outside air is higher than that of the return air, the return air is often cooled by the air conditioner alone without mixing it with the outside air. The shape and size of the return air vent and the outside air vent are arbitrary. Furthermore, the number of return air vents and outside air vents can be appropriately changed, for example, depending on the number of air conditioners.

[0013] The material of the first wind direction adjustment member is not limited. For example, various metals such as iron, stainless steel, and aluminum alloy can be used. Other materials such as various plastics may also be used. The shape of the first airflow adjustment member is arbitrary. For example, it may be plate-shaped, folded plate-shaped with a horizontal return / outlet section that slopes in the middle, cylindrical, etc. The number of the first airflow adjustment members used is also arbitrary. For example, it may be changed as appropriate depending on the number of air conditioners and return air vents.

[0014] If the first airflow adjustment member is absent, for example, if the distance from the return air inlet to the other wall is 4m, the height of the air conditioning machine room is 5m, the discharge velocity from the return air inlet is 6m / s, the outside air discharge velocity from the top of the second airflow adjustment member is 6m / s, and the flow rate ratio of return air to outside air is 3:1, then the return air flow blown horizontally from the return air inlet will create a short circuit, drawing an arc that changes direction 180 degrees downwards before being drawn into the air conditioner. At the same time, most of the outside air blown out from the top of the second airflow adjustment member rises between the arc-shaped return air flow and the other wall. This results in uneven mixing of return air and outside air within the air conditioning unit room, causing problems such as large variations in temperature and flow rate of the intake air at the intake port, which is approximately 3m high in the air conditioner's height direction.

[0015] If the inclination angle of the first airflow adjustment member is less than 30°, for example, if the length of the inclined portion is 1.5 times or less the height of the return air inlet, and the discharge velocity from the return air inlet is 8 m / s or less, a short circuit of the return air will occur, similar to the case where the first airflow adjustment member is absent. This results in the inconvenience that most of the outside air discharged from the top of the second airflow adjustment member will rise between the arc-shaped return air flow and the other wall. Furthermore, if the first airflow adjustment member is folded and its inclined portion exceeds 90°, a disadvantage arises: pressure loss occurs in the return air flowing along the ceiling of the air conditioning machine room to the other wall.

[0016] In particular, the preferred upward inclination angle of the first airflow adjustment member is 45° to 60°. Within this range, for example, even if the length of the inclined portion is 1x the height of the return air inlet, most of the return air flows along the ceiling and descends at the other wall, and the upward flow of outside air blown out from the top of the second airflow adjustment member bends towards one wall, allowing the descending high-temperature return air to flow between the rising outside air and the other wall, thereby promoting mixing and providing an even more favorable effect.

[0017] The second air direction adjusting member is a member for raising the outside air introduced from the outside air inlet into the air conditioning machine room upward (for example, directly upward) along the other wall. In addition, an inclined plate inclined in the direction of one wall or an inclined plate that allows the upward flow to spread left and right in a direction parallel to the other wall is attached to the upper blowing outlet of the second air direction adjusting member, so that the mixing of the outside air and the return air in the upper space of the air conditioning machine room can be made over a wide range. The material of the second air direction adjusting member is not limited. For example, various metals such as iron, stainless steel, and aluminum alloy can be adopted. In addition, various plastics and the like may also be used. The shape of the second air direction adjusting member is arbitrary, and it may be cylindrical or plate-shaped.

[0018] In addition, the invention according to claim 2 is a method for mixing airflows in a data center air conditioning machine room according to claim 1, characterized in that the upward inclination angle of the first air direction adjusting member is 45° to 60°. On one wall of the air conditioning machine room, a plurality of air conditioners, a plurality of return air inlets, and a plurality of first air direction adjusting members are arranged horizontally at predetermined intervals. However, it is desirable that the lateral width of the first air direction adjusting member is not less than the width of the return air inlet, and it may be a lateral width such that most of the return air blown out from the return air inlet changes direction due to the inclination of the first air direction adjusting member and flows along the ceiling. Also, the gap between adjacent first air direction adjusting members may be eliminated.

[0019] Furthermore, the invention according to claim 3 is a method for mixing airflows in a data center air conditioning machine room according to claim 1 or claim 2, characterized in that on one wall of the air conditioning machine room, a plurality of the air conditioners, a plurality of the return air inlets, and a plurality of the first air direction adjusting members are arranged horizontally at predetermined intervals, a control panel for controlling each of the air conditioners is installed on the other wall of the air conditioning machine room, and a horizontally long cable rack for placing an electric cable extending from the control panel to each of the air conditioners is arranged between the upper front side of each of the air conditioners and each of the first air direction adjusting members.

[0020] Furthermore, the invention according to claim 4 is a method for mixing airflows in a data center air conditioning machine room according to claim 1 or claim 2, characterized in that the first airflow direction adjusting member is a horizontally long multi-stage upward blade plate. The number of upward blade plates constituting the first airflow direction adjusting member can be arbitrarily set as long as it is two or more. The inclination angle of each upward blade plate is 30° to 60°, preferably 45° to 60°. The interval between adjacent upward blade plates is arbitrary.

[0021] The invention according to claim 5 is a method for mixing airflows in a data center air conditioning machine room according to claim 1, characterized in that the upper air outlet of the second airflow direction adjusting member is separated from the other wall by 10 cm or more, or inclined blades for blowing the outside air obliquely in the direction of one wall of the air conditioning machine room are attached to the upper air outlet, or both, so that the return air descending along the other wall is mixed into the space between the outside air rising from the upper air outlet of the second airflow direction adjusting member and the other wall.

[0022] The invention according to claim 6 is a method for mixing airflows in a data center air conditioning machine room according to claim 1, characterized in that a plurality of the outside air inlets and the second airflow direction adjusting members are arranged horizontally at a predetermined interval on the other wall of the air conditioning machine room, and outside air outlets for blowing out the outside air are provided on the left and right side surfaces of the second airflow direction adjusting member. [[ID=​​​​​​​​​​

[0024] According to the present invention, the return air that has passed from the data room through the return air inlet and returned to the air conditioning machine room is guided along the ceiling of the air conditioning machine room toward the other wall via a first airflow adjustment member. Meanwhile, the outside air introduced into the air conditioning machine room from the outside air inlet is directed upward along the other wall by a second airflow adjustment member. As a result, these return air and outside air are mixed in the upper space on the other wall side of the air conditioning machine room. The resulting mixed air is then drawn into an air conditioner, where it is humidified as needed and cooled to a suitable temperature before being supplied to the server room as supply air.

[0025] In this way, by mixing the return air and outside air in the upper space on the other wall side, farther away from the air conditioner, within the air conditioning machine room, the mixing of the return air and outside air is promoted, the occurrence of short circuits in the return air and outside air is suppressed, and the intake temperature and flow rate of the air into the air conditioner can be made uniform, which in turn can save energy on the air conditioner.

[0026] In particular, according to the invention described in claim 2, since the upward inclination angle of the first airflow adjustment member is set to 45° to 60°, there is no short circuit of return air to the air conditioner intake, and most of the return air flows along the ceiling with little pressure loss and descends at the other wall. Furthermore, the descending high-temperature return air flows between the rising flow of outside air blown from the top of the second airflow adjustment member and the other wall, promoting mixing.

[0027] Furthermore, according to the invention described in claim 3, a plurality of air conditioners, a plurality of return air vents, and a plurality of first airflow adjustment members are arranged horizontally at predetermined intervals on one wall of the air conditioning machine room, and a control panel for controlling each air conditioner is installed on the other wall of the air conditioning machine room, and a horizontally elongated cable rack is placed between the front upper part of each air conditioner and each first airflow adjustment member to support the electrical cables extending from the control panel to each air conditioner.

[0028] This has the effect of not obstructing the mixing of return air and outside air in the upper space on the other wall side, far from the air conditioner's intake port, within the air conditioning machine room. Furthermore, if there is a gap between adjacent first airflow adjustment members, some of the return air will leak out of the flow path on the inclined plate of the first airflow adjustment member and flow into the air conditioner's intake with insufficient mixing with the outside air, resulting in a malfunction. A horizontally elongated cable rack provides a detour, allowing some of the return air that leaked out to flow further away from one wall, thus promoting mixing with the outside air.

[0029] Furthermore, according to the invention described in claim 4, since a horizontally elongated, multi-stage upward-facing vane is adopted as the first airflow adjustment member, it becomes possible to attach it directly to the return air inlet, and the effect is obtained that support material from the ceiling or one wall to the first airflow adjustment member is not required.

[0030] According to the invention described in claim 5, the upper outlet of the second airflow adjustment member is positioned at least 10 cm away from the other wall, or an inclined vane is attached to the upper outlet that blows air diagonally towards one wall of the air conditioning machine room, or both are employed. This makes it easier for the return air descending along the other wall to mix with the outside air rising from the upper outlet of the second air direction adjustment member, thereby promoting the mixing of the return air and outside air in the upper space on the other wall side, which is far from the air intake of the air conditioner.

[0031] According to the invention described in claim 6, on the other wall of the air conditioning machine room, a plurality of outside air vents and a second airflow adjustment member are arranged laterally at predetermined intervals, and outside air outlets for blowing out outside air are provided on the left and right sides of the second airflow adjustment member. As a result, high-temperature return air with less mixing with outside air descends into the space between the adjacent second air direction adjustment member. By blowing outside air out from the outside air outlet on the side of the second air direction adjustment member and mixing it with the return air, the effects of uniformity, which reduces variations in the mixed temperature, and the effects of increasing the flow rate in the lower space of the air conditioning machine room, which helps to uniformize the intake flow rate of the air conditioner.

[0032] In data centers, multiple air conditioners are modularized by providing one control panel for each unit, and these modules are expanded to create larger systems. In some cases, the distance between adjacent second airflow adjustment members may increase due to the control panel, etc. By varying the opening area of ​​the outside air outlet, it is possible to increase the amount of outside air flowing out and equalize the mixed temperature.

[0033] According to the invention described in claim 7, the return air flowing through the passage above the air conditioning machine room is blown downward into the air conditioning machine room from an opening or return air port formed beside the other wall, and the return air descending along the other wall flows between the outside air rising from the second air direction adjusting member and the other wall, thereby promoting mixing. [Brief explanation of the drawing]

[0034] [Figure 1] This is an overall side view of an air conditioning system illustrating an airflow mixing method in a data center machine room according to Embodiment 1 of the present invention. [Figure 2] This is a perspective view showing an airflow mixing method in a data center machine room according to Embodiment 1 of the present invention. [Figure 3] This is a side view showing the airflow in a short-circuit in a data center machine room using conventional technology. [Figure 4] (a) is a plan view of the entire data center according to Embodiment 1 of the present invention. (b) is a side view of the entire data center according to Embodiment 1 of the present invention. [Figure 5] This is a cross-sectional view of a second airflow adjustment member in a data center machine room according to Embodiment 1 of the present invention. [Figure 6] This is a side view of an alternative shape of the first airflow adjustment member for a data center machine room according to the present invention. [Figure 7] This is a side view showing the position of the return air vent in the data center machine room of the present invention, with the location of the vent shifted. [Modes for carrying out the invention]

[0035] The following describes specific embodiments of the present invention. [Examples]

[0036] First, let's consider the use of this invention during winter and the transitional seasons as an example. In describing the airflow mixing method in a data center machine room according to Embodiment 1 of the present invention, we will first describe the air conditioning equipment 10 of the data center. As shown in Figure 1, this air conditioning system 10 has a server room 11 in a data center. Adjacent to this server room 11 is an air conditioning machine room 13 which houses numerous air conditioners 12 that cool the high-temperature (e.g., 36°C) return air a generated in the server room 11 and supply it to the server room 11 as supply air (e.g., 27°C) b.

[0037] The server room 11 houses numerous computers 15 arranged in large server racks 14. The racks 14 are separated into a cold aisle 16 through which cooling air (supply air b) passes and a hot aisle 17 through which heated air (return air a) passes. The supply air b to the server room 11 may be blown out from under the floor of the cold aisle 16. Furthermore, the return air a that has passed through the hot aisle 17 is returned to the air conditioning machine room 13 via the ceiling duct 18 above the server room 11. A cold aisle ceiling 34 with insulating properties is installed between the ceiling of the cold aisle 16 and the ceiling duct 18. A chimney 20 with a fan 19 is connected to the upper part of the ceiling duct 18. The plan view in Figure 4(a) is a cross-sectional view at the location of the cold aisle 16. Instead of the fan 19, the chimney 20 may be provided with the exhaust port 19' shown in Figure 4(b), allowing for natural exhaust at the same flow rate as the outside air c.

[0038] As shown in Figures 1 and 2, the air conditioning machine room 13 has six rectangular return air vents 22 arranged horizontally at predetermined intervals on the upper part of the wall 21 on the server room side (one wall), through which the return air a from the server room 11 passes. At the lower end of each return air vent 22, six first air direction adjustment plates (first air direction adjustment members) 24 are provided, each inclined 45° upward to guide the return air a that has passed through the corresponding return air vent 22 along the ceiling of the air conditioning machine room 13 toward the outdoor wall (the other wall) 23. Alternatively, a horizontally elongated four-stage upward-facing vane (first air direction adjustment member) 25 may be used instead of the first air direction adjustment plates 24 (see the dashed-dotted frame in Figure 1). In this case, direct attachment to the return air vent 22 becomes possible, eliminating the need for support materials from the ceiling, the server room wall 21, or the return air vent 22, as is required with the first air direction adjustment plates 24. Furthermore, six air conditioners 12 are arranged horizontally at predetermined intervals in the portion of the server room wall 21 below each return air vent 22. If there is a large gap between adjacent air conditioners 12, a partition plate 26 may be placed between them.

[0039] On the other hand, at the lower part of the outdoor wall 23 facing the server room wall 21, there are six rectangular outdoor air vents 27 arranged horizontally at predetermined intervals to bring in outside air c, which is cooler than the return air a (for example, 20°C), into the air conditioning machine room 13. In front of each outside air vent 27, six rectangular tubular airflow adjustment ducts (second airflow adjustment members) 28, each with an open upper end, are arranged laterally at predetermined intervals to direct the outside air c that has passed through the corresponding outside air vent 27 upward along the outdoor wall 23. At the front ends of the left and right side plates 28a of each second airflow adjustment duct 28, a pair of left and right outside air outlets 29 are formed to allow a portion of the outside air c to flow out to the side.

[0040] Furthermore, a control panel 30 that controls all the air conditioners 12 collectively is installed between the third and fourth units of the second air direction adjustment duct 28 in the lower part of the outdoor wall 23. Numerous electrical cables 32 are connected to each air conditioner 12 from the control panel 30 via cable racks 31 that are routed to predetermined locations. Between the front upper part of each air conditioner 12 and each first air direction adjustment plate 24, a horizontally elongated air conditioner-side rack (horizontally elongated cable rack) 33 is positioned, which constitutes the air conditioner 12-side portion of the cable rack 31.

[0041] In this embodiment, six air conditioners 12 are modularized with one control panel 30, but the number of air conditioners 12 can be more or less than six. Data centers are scaled up by adding many modules. In Figures 1 and 3, the symbol P represents four pipes. By piping them above the air conditioning machine room 13, it is expected that the airflow will be disturbed, promoting the mixing of return air a and outside air c.

[0042] Next, with reference to Figures 1 and 2, the airflow mixing method for the data center air conditioning machine room according to Embodiment 1 of the present invention in the air conditioning equipment 10 of the data center will be described. In the server room 11 of the air conditioning system 10, the low-temperature supply air b blown out from each air conditioner 12 passes through the cold aisle 16, cooling and deheating the numerous heat-generating computers 15 arranged in the server racks 14, and becomes high-temperature return air a. Multiple small fans (not shown) are often installed inside the server racks 14 to forcibly exhaust air from the cold aisle 16 to the hot aisle 17, reducing variations in cooling depending on the location. This return air a passes through the hot aisle 17, rises through the server room 11, and flows into the ceiling duct 18. The return air a then passes through the ceiling duct 18 and is returned to the air conditioning machine room 13 through each return air outlet 22. A portion of the return air a that flows into the ceiling duct 18 is exhausted outdoors through a fan 19 with a flow rate adjustment function in the chimney 20.

[0043] Next, the high-temperature (e.g., 36°C) return air a that has passed through each return air outlet 22 and returned to the air conditioning machine room 13 is guided by each first air direction adjustment plate 24, which is inclined upward by 45°, and is directed along the ceiling of the air conditioning machine room 13 towards the outdoor wall 23. Meanwhile, the low-temperature (e.g., 22°C) outside air c introduced into the air conditioning machine room 13 from each outside air inlet 27 is guided by each second air direction adjustment duct 28 and rises along the outdoor wall 23.

[0044] As a result, in the upper space on the outdoor side wall 23 of the air conditioning machine room 13, the high-temperature return air a and the low-temperature outside air c are mixed, and the temperature of the mixed air d is lowered to, for example, around 27°C (see Figure 1). Next, the mixed air d is drawn into the corresponding air conditioners 12.

[0045] The mixing ratio of return air a and outside air c in the air conditioning machine room 13 is adjusted by controlling the opening of the return air damper 38 installed upstream of the return air inlet 22 and the outside air damper 40 installed next to the outside air inlet 27. The airflow within the air conditioner 12 draws in mixed air d from the air conditioning machine room 13 through the intake port 50, humidifies it by the humidifier 35 if necessary, and cools or dehumidifies it by a heat exchanger such as a chilled water coil 36. If it is necessary to heat the humidified air, the bypass damper 39 is opened, and bypass air e, which is separated from the return air a within a suitable dew point temperature range, is introduced into the air conditioner 12 and mixed. Next, the supply air b is rectified (not shown) by the blower fan 37 and blown out into the cold aisle 16.

[0046] When the outside air c has an absolute humidity within a suitable dew point temperature range (for example, a dew point temperature of 5.5 to 15°C) and the temperature is around 13°C, the air conditioner 12 does not use heat sources for humidification or cooling, but instead adjusts the opening of the return air damper 38 and the outside air damper 40 to bring the mixed air d and the supplied air b to an appropriate temperature (for example, 27°C).

[0047] If we define the ratio of the flow rate of outside air c to the supply air b as the outside air intake ratio f, then it is desirable for the outside air intake ratio f to be 50% or less. If the outside air c is 24°C within a suitable dew point temperature range (e.g., dew point temperature 5.5~15°C) and the return air a is 36°C, then, for example, the outside air c and return air a are mixed in the air conditioning machine room 13 at the maximum outside air intake ratio f, and then cooled to a suitable temperature (e.g., 27°C) by the cooling coil 36.

[0048] If the enthalpy of the outside air c is lower than that of the return air a, but is higher than the suitable dew point temperature range (for example, a dew point temperature of 15°C or higher), dehumidification is necessary. After mixing the outside air c and the return air a, the mixed air d is cooled and dehumidified by the cooling coil 36 to an absolute humidity of 15°C. The bypass damper 39 is opened and mixed with the bypass air e separated from the high-temperature return air a to produce supply air b at a suitable temperature (for example, 27°C).

[0049] If the outside air c is cold and its dew point temperature is lower than the target dew point temperature (e.g., 5.5°C), then, if the outside air c is, for example, 0°C, the outside air c and return air a are mixed and then humidified in the humidifier 35 to the target dew point temperature to produce supply air b at a suitable temperature (e.g., 27°C). If the outside air c is, for example, 16°C, then after mixing and humidification, it is further cooled to produce supply air b at a suitable temperature (e.g., 27°C).

[0050] As shown in Figure 5, an outside air diffuser 41 may be attached to the upper outlet 48 of the second air direction adjustment duct 28 to facilitate mixing with the downward flow a' of the return air. Furthermore, by making the opening area of ​​the outside air outlet 29 of the left and right plates 28a of the second wind direction adjustment duct 28 variable, for example, in places where the distance between the third and fourth units of the second wind direction adjustment duct 28 is wide due to the presence of the central control panel 30, the flow rate of the downdraft a' of high-temperature return air with less mixing with outside air c increases. In response to this, the third second airflow adjustment duct 28 allows for flow rate adjustment by increasing the opening area of ​​the outside air outlet 29 on the control panel 30 side to increase the flow rate of the discharged outside air c'', and decreasing the opening area of ​​the outside air outlet 29 on the opposite side to decrease the flow rate of the discharged outside air c''''. Outside air c' represents the normal flow rate. This results in improved uniformity of mixing temperature and flow rate in the lower space of the air conditioning machine room 13.

[0051] As shown in Figure 3, if the first air direction adjustment plate 24 and the second air direction adjustment duct 28 are absent, a short circuit occurs in which most of the return air a and outside air c are not mixed and are directly drawn into each air conditioner 12. In this embodiment, the upward tilt angle of the first air direction adjustment plate 24 in the air conditioning machine room 13 is set to 45°, so that most of the return air a flows along the ceiling with little pressure loss. Next, by mixing high-temperature return air a and low-temperature outside air c in the upper space on the outdoor wall 23 side, which is farther away from each air conditioner 12, the occurrence of short circuits can be suppressed.

[0052] As shown in Figure 7, an inclined vane 49 may be attached to the upper outlet 48 of the second airflow adjustment duct 28 to facilitate mixing of the downward flow a' of return air and the outside air c. Alternatively, instead of the inclined vane 49, the upper outlet 48 may be placed at least 10 cm away from the outdoor wall (the other wall) 23.

[0053] This makes it easier for the downward flow a' of return air to mix with the upward flow of outside air c that is blown out from the top of the second air direction adjustment duct 28 and curves towards the wall 21 on the server room side, and the downward flow a' of return air between it and the wall 23 on the outdoor side, thereby promoting the mixing of return air a and outside air c.

[0054] In Figure 3, the same symbols as in Figure 1 indicate the same components. When the horizontally elongated air conditioner-side rack 33 is positioned near the outdoor wall 23, it separates the flow of return air a and outside air c within the air conditioning machine room 13, thus hindering mixing.

[0055] On the other hand, in Embodiment 1, six air conditioners 12, six return air vents 22, and six first airflow adjustment members are arranged horizontally at predetermined intervals on the server room side wall 21, and a control panel 30 for controlling each air conditioner 12 is installed on the outdoor side wall 23, and a horizontally elongated air conditioner side rack 33 is placed between the front upper part of each air conditioner 12 and each first airflow adjustment plate 24 to support the electrical cables 32 extending from the control panel 30 to each air conditioner 12. As a result, the horizontally elongated rack 33 on the air conditioner side does not obstruct the mixing of return air a and outside air c, and also has the effect of guiding the return air a that leaks to the side from the first air direction adjustment plate 24 to the center of the air conditioning machine room 13.

[0056] Furthermore, since a pair of left and right outside air outlets 29 are provided at the front ends of the left and right right plates 28a of each second air direction adjustment duct 28 to allow a portion of the outside air c to flow out laterally, mixing the outside air c' flowing out from these outside air outlets 29 with the descending flow a' of high-temperature return air, which has less mixing with the outside air c, improves the uniformity of the mixed temperature and flow rate in the lower space of the air conditioning machine room 13. Furthermore, if the distance between adjacent second wind direction adjustment members 28 changes in the control panel 30 or the like, the amount of outside air outflow can be adjusted by varying the opening area of ​​the outside air outlet 29 to equalize the mixing temperature.

[0057] As shown in Figure 6, a long guide plate 42 that is tilted upward at 45° and then folded horizontally is attached to the return air inlet 22, and an air conditioning machine room return air passage (passage) 43 is provided in the ceiling of the air conditioning machine room 13, so that the return air a flows towards the upper space on the outdoor side wall (the other wall) 23 and is blown downward from the opening 44. As a result, the high-temperature return air a and the low-temperature outside air c are mixed in the upper space on the outdoor wall 23 side, which is farther away from each air conditioner 12. This improves the uniformity of the mixing temperature and suppresses the occurrence of short circuits. In addition, the long guide boards 42 may be arranged continuously in the horizontal direction without predetermined intervals.

[0058] As shown in Figure 7, a ventilation opening 45 is provided in the ceiling of the server room side wall (one wall) 21, and return air a flows into the air conditioning machine room ceiling duct (passage) 46 in the ceiling of the air conditioning machine room 13, and the downward flow a' of return air is blown downward from the upper ceiling return air opening 47 on the outdoor side wall (the other wall) 23. As a result, the return air a descending along the outdoor wall 23 mixes with the outside air c rising from the second wind direction adjustment duct 28 and the outdoor wall 23, thereby promoting mixing.

[0059] In the summer, if the enthalpy of the outside air c is higher than that of the return air a, the air conditioning machine room 13 circulates only the return air a without using the outside air c, and this is cooled by the cooling coil 36. In this case, since there is no mixing with outside air c, the flow rate of return air a passing through each return air port 22 of the air conditioning machine room 13 increases. However, the return air a is guided by each first air direction adjustment plate 24, which is tilted upward by 45° according to the present invention, and is directed to the upper space on the outdoor side wall 23, which is farther away from each air conditioner 12. As it descends while slowing down and diffusing, short circuits do not occur, and the suction flow rate to the intake port 50 of the air conditioner 13 is less variable. [Industrial applicability]

[0060] The present invention is useful as an airflow mixing method in a data center machine room for mixing high-temperature air flowing in from the server room with low-temperature outside air flowing in from the outdoors. [Explanation of Symbols]

[0061] 10. Air conditioning equipment for data centers 11 Server Room 12 Air conditioner 13. Air conditioning machine room 21. The wall on the server room side (one of the walls) 22 Return air port 23. The outdoor wall (the other wall) 24. First wind direction adjustment plate (first wind direction adjustment member) 25 Upward-facing vane (first wind direction adjustment member) 27. Outdoor air vent 28. Second airflow adjustment duct (second airflow adjustment member) 29 Outside air outlet 30 Control Panel 31 Cable Rack 33. Rack on the side of the air conditioner (a long, horizontal cable rack) 43. Air conditioning machine room return air passage (passage) 44 openings 46. ​​Air conditioning machine room ceiling duct (passageway) 47 Ceiling air return vent 48 Upper air outlet 49 Inclined blades a. Return air b. Supply air c Outside air d Mixed air e Bypass Air

Claims

1. In an air conditioning machine room located adjacent to the server room of a data center, and containing an air conditioning unit that cools the high-temperature return air from the server room and supplies it to the server room, a method for mixing airflow in a data center air conditioning machine room involves mixing the return air from the server room with outside air that is cooler than the return air from the outside, A return air vent for the return air from the server room is formed in the upper part of one wall of the aforementioned air conditioning machine room. The return air inlet is provided with a first airflow direction adjusting member that is inclined 30° to 90° upward to guide the return air that has passed through the return air inlet along the ceiling of the air conditioning machine room toward the other wall. The air conditioner is installed in the lower part of one wall of the aforementioned air conditioning machine room, below the return air vent. An outside air vent is formed in the lower part of the other wall opposite to one wall of the aforementioned air conditioning machine room, to allow outside air to enter the air conditioning machine room. The outside air vent is provided with a second airflow adjustment member that causes the outside air that has passed through the outside air vent to rise along the other wall. A method for mixing airflow in a data center air conditioning machine room, characterized in that the return air that has passed through the return air inlet is guided by the first airflow direction adjusting member along the ceiling of the air conditioning machine room toward the other wall, while the outside air that has passed through the outside air inlet is raised along the other wall by the second airflow direction adjusting member, thereby mixing the return air and the outside air in the upper space on the other wall side of the air conditioning machine room before they are drawn into the air conditioner.

2. The airflow mixing method for a data center air conditioning machine room according to claim 1, characterized in that the upward inclination angle of the first airflow adjustment member is 45° to 60°.

3. On one wall of the aforementioned air conditioning machine room, a plurality of the aforementioned air conditioners, a plurality of the aforementioned return air vents, and a plurality of the aforementioned first air direction adjustment members are arranged laterally at predetermined intervals from each other. On the other wall of the aforementioned air conditioning machine room, a control panel for controlling each of the aforementioned air conditioners is installed. The method for mixing airflow in a data center air conditioning machine room according to claim 1 or 2, characterized in that a horizontally elongated cable rack for supporting electrical cables extending from the control panel to each air conditioner is arranged between the front upper part of each air conditioner and each of the first airflow direction adjusting members.

4. The airflow mixing method for a data center air conditioning machine room according to claim 1 or 2, characterized in that the first airflow adjustment member is a horizontally elongated, multi-stage upward-facing vane.

5. The method for mixing airflow in a data center air conditioning machine room according to claim 1, characterized in that the upper outlet of the second airflow adjustment member is placed at least 10 cm away from the other wall, or an inclined vane is attached to the upper outlet to diagonally blow the outside air toward one wall of the air conditioning machine room, or both, thereby mixing the outside air rising from the upper outlet of the second airflow adjustment member with the return air descending along the other wall between the outside air and the other wall.

6. On the other wall of the air conditioning machine room, a plurality of the aforementioned outside air vents and the second airflow adjustment members are arranged laterally at predetermined intervals. The airflow mixing method for a data center air conditioning machine room according to claim 1, characterized in that outside air outlets for blowing out the outside air are provided on the left and right sides of the second airflow adjustment member.

7. The airflow mixing method for a data center air conditioning machine room according to claim 5 or 6, characterized in that a passage for the return air is provided in the upper part of the air conditioning machine room, and the return air is blown downward from an opening or ceiling return air outlet formed next to the other wall of the passage.

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