Claims:
WE CLAIM:
1. A rack cooling unit (1000) for cooling electronics mounted on a rack (5), said rack cooling unit (1000) comprising:
a. an indoor unit (10) mounted on said rack (5) and configured to cool air sucked from space external to said indoor unit (10);
b. an outdoor unit (20) configured to discharge to external surroundings heat withdrawn by said indoor unit (10); and
c. a cooling fluid circulated between said indoor unit (10) and said outdoor unit (20);
wherein said indoor unit (10) comprises:
i. heat exchanging means (107) over which warm air is made to flow, thus causing the air to cool down;
ii. a fan (105) for blowing air cooled through said rack; and
iii. an inlet guide ring (106) disposed at the inlet side of said fan (105) for generating a convergent streamlined flow of air at the inlet of said fan (105).
2. The rack cooling unit (1000) as claimed in claim 1, wherein said fan (105) is a backward curved centrifugal fan.
3. The rack cooling unit (1000) as claimed in claim 1, wherein said indoor unit (10) is assembled inside an enclosure (101).
4. The rack cooling unit (1000) as claimed in claim 3, wherein said enclosure (101) is provided with air outlet grilles (103), each of said air outlet grilles (103) is provided with a cover plate (104) for selectively directing flow of air from said indoor unit (10).
5. The rack cooling unit (1000) as claimed in claim 4, wherein said air outlet grilles (103) are provided one at an operative top surface and one at an operative bottom surface of said indoor unit (10).
6. The rack cooling unit (1000) as claimed in claim 1, wherein said heat exchanging means (107) is an evaporator.
7. The rack cooling unit (1000) as claimed in claim 6, wherein said outdoor unit (200) comprises a condenser.
8. The rack cooling unit (1000) as claimed in claim 1, wherein said outdoor unit (20) is a chiller unit.
, Description:FIELD
The present disclosure lies in the field of rack cooling units.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Server rack cooling units are developed to impart closed-loop cooling for critical servers and server equipment. The units work on closed loop cooling concept, wherein the hot air from rack will be sucked from the cooling coil and circulated using a blower. A split type rack unit having an indoor unit and an outdoor unit is commonly used in rack cooling applications.
Certain desirable characteristics of a rack cooling unit are high cooling efficiency, optimal air distribution, low noise and a small spatial foot print.
The most common type of cooling principle used is the vapour compression cycle. The energy consumption of cooling units employing a vapour compression cycle makes the split type rack cooling units expensive while in operation due to an inherently low coefficient of performance achievable using vapour compression cycle. Hence, a rack cooling unit is desired, which also incurs less operating cost.
A rack cooling unit is required, which caters to above mentioned requirements.
OBJECT
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
A primary object of the present invention is to provide a rack cooling unit.
Another object of the present invention is to provide a rack cooling unit, which provides high cooling efficiency.
Yet another object of the present invention is to provide a rack cooling unit, which gives optimal air distribution.
Still another object of the present invention is to provide a rack cooling unit, which incurs less operating cost.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a rack cooling unit for cooling electronics mounted on a rack. The rack cooling unit comprises an indoor unit and an outdoor unit. The indoor unit is mounted on the rack and is configured to cool air sucked from space external to the indoor unit. The outdoor unit is configured to discharge to external surroundings heat withdrawn by the indoor unit. A cooling fluid circulates between the indoor unit and the outdoor unit. The indoor unit comprises a heat exchanging means, a fan and an inlet guide ring. Warm air is made to flow over the heat exchanging means, thus causing the air to cool down. The fan is for blowing air cooled through the rack. The inlet guide ring is at the inlet side of the fan for generating a convergent streamlined flow of air at the inlet of the fan.
The indoor unit is assembled inside an enclosure. The enclosure is provided with air outlet grilles, each of the air outlet grilles is provided with a cover plate for selectively directing flow of air from the indoor unit. The air outlet grilles are provided one at an operative top surface and one at an operative bottom surface of the indoor unit.
In an embodiment, the fan is a backward curved centrifugal fan.
In an embodiment, the heat exchanging means is an evaporator and the outdoor unit comprises a condenser. In another embodiment, the outdoor unit is a chiller unit.

BRIEF DESCRIPTION ACCOMPANYING DRAWING
A rack cooling unit, of the present disclosure, will now be described with the help of the accompanying drawing, in which:
Figure 1 shows a rack cooling unit in accordance with an embodiment of the present disclosure;
Figure 2 shows a rack cooling unit in accordance with another embodiment of the present disclosure;
Figure 3 shows an indoor unit of the rack cooling unit in accordance with an embodiment of the present disclosure;
Figure 4 shows a rack with the indoor unit in accordance with an embodiment of the present disclosure;
Figure 5 shows a rack with the indoor unit in accordance with another embodiment of the present disclosure;
Figure 6 shows a rack with the indoor unit in accordance with yet another embodiment of the present disclosure;
Figure 7 shows an exploded view of the indoor unit of Figure 1;
Figure 8 shows an exploded view of the indoor unit of Figure 2; and
Figure 9 shows another exploded view of the indoor unit of Figure 3.
LIST OF REFERENCE NUMERALS
1000 - rack cooling unit
5 - rack
10 - indoor unit
20’ - outdoor unit of prior art
20 - outdoor unit of the present disclosure
30 - cooling fluid tubes
101 - enclosure
101a - top lid
101b - tray
102 - front lid
103 - air outlet grille
104 - cover plate
105 - fan
106 - inlet guide ring
107 - heat exchanging means
108 - expansion valve
109 - rack mounting channel
1010 - drainage pan
1011 - service valve
1012 - drainage outlet
1013 - controller
1014 - transformer
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a”, “an”, and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises”, “comprising”, “including” and “having” are open ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
When an element is referred to as being “mounted on”, “engaged to”, “connected to” or “coupled to” another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper”, and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
The rack cooling unit 1000, of the present disclosure, is now described with reference to Figures 1-9. The rack cooling unit 1000 is a split type rack cooling unit comprising an indoor unit 10 and an outdoor unit 20 which are coupled by means of cooling fluid tubes 30. The cooling fluid tubes 30 are preferably made of copper. The indoor unit 10 is configured to exchange heat with the inlet air and thereby cool the inlet air and discharge the cool air into the space within the rack 5. In an embodiment, as shown in Figure 1, the outdoor unit 20a is a condenser. In another embodiment, as shown in Figure 2, the outdoor unit 20b is a chiller unit. In an embodiment, the indoor unit 10 encloses an evaporator and an expansion valve, as shown in Figure 7. In another embodiment, the indoor unit 10 encloses a heat exchanger, as shown in Figure 8.
The indoor unit 10 of the present disclosure comprises a fan 105, an inlet guide ring 106, and a heat exchanging means 107, which are assembled and enclosed in an enclosure 101. The enclosure 101 is formed by a tray 101a and a top lid 101b. The tray 101a and the top lid 101b are sheet metal plates, preferably galvanized or paint-coated stainless steel. A rack mounting channel 109 is provided for mounting the enclosure 101 within the rack 5. In an embodiment, the heat exchanging means 107 is an evaporator, as illustrated in Figure 7. In another embodiment, the heat exchanging means 107 is a cold water coil, as illustrated in Figure 8. The enclosure 101 has a filter 104 through which warm air from the space surrounding the rack 5 is sucked in. The cooling fluid cooled by the outdoor unit 10 and flowing through the cooling tubes 30, enters the heat exchanging means 107. The warm air is made to flow over the heat exchanging means 107 which causes the warm air to cool down. The fan 105 is configured to propel the cooled air at the required velocity through the components stacked in the rack 5. A transformer 1014 transforms electrical power supply to the required potential difference for driving the fan 105. A controller 1013 is configured to control the speed of the fan according to the cooling load present. The cooled air propelled by the fan 105 is discharged through an air outlet grille 103, wherein two air outlet grilles 103 are formed on opposite lateral surfaces of a front lid 102. In an operative mounted configuration, the air outlet grilles 103 are disposed to direct flow of air along the vertical axis, i.e., either upwards or downwards or both, of the rack 5. The lateral surface of the front lid 102 opposite to that of the air outlet grille 103 that is to be kept open can selectively be closed using a cover plate 103.
In the embodiment of the rack cooling unit 1000 illustrated in Figure 8, the cold water coil (i.e., the heat exchanging means) 107 is designed for high sensible heat, wherein the sensible heat factor is higher than 0.95. A two-way pressure independent chilled water valve (not shown in Figures) is used for controlling the cooling capacity of the coil 107, which changes the flow rate in the coil 107 based on input. The controller 1013 varies the inputs of the control valve and the fan 105 to control the rated cooling capacity.
The controller 1013 is configured to cooperate with a repository. The control unit is further configured to generate processing commands. In an embodiment, the control unit is implemented as one or more microprocessors, microcomputers, digital signal processors, central processing units, state machines, logic circuitries, and/or any devices that manipulate signals based on operational instructions.
According to an aspect of the present disclosure, the indoor unit 10 can be disposed in various configurations within the rack 5. In an embodiment, as shown in Figure 4, the indoor unit 10 is disposed at the top of the rack 5, with the server units and other electronic equipment stacked below the indoor unit 10. The cover plate 104 covers the top air outlet grille 103. In another embodiment, as shown in Figure 5, the indoor unit 10 is disposed in the middle of the rack 5, with the server units and other electronic equipment stacked above and below the indoor unit 10. Both of the air outlet grilles 103 are kept open. In yet another embodiment, as shown in Figure 6, the indoor unit 10 is disposed at the bottom of the rack 5, with the server units and other electronic equipment stacked above the indoor unit 10. The cover plate 104 covers the bottom air outlet grille 103.
According to an aspect of the present disclosure, the fan 105 is of backward curved centrifugal type, which propels air radially and uniformly in all the directions. The velocity of the air output by the fan 105 is varied by the controller 1013. The fan 105 is thus capable of delivering supply air in upward and downward direction both. This gives flexibility of mounting the indoor unit 10 at bottom or top or in the middle of the rack 5, as is illustrated in Figures 4, 5 and 6 respectively.
According to another aspect of the present disclosure, an inlet guide ring 106 is disposed at the inlet of the fan 105. The inlet guide ring 106 is shaped so as to generate optimal convergent streamlined flow of air at the inlet of the fan 105. In a preferred embodiment, the inlet guide ring 106 has an arcuate radial cross-section. The geometry of the curvature of the inlet guide ring 106 is optimized by considering the dimensions of the fan 105.
Besides, the enclosure 101 is provided with a drainage pan 1011 for collecting drain water that might be accumulated due to condensation. Further to the drainage pan 1011, a drainage outlet 1012 is also provided. Also, a pair of service valves 1012 is provided for facilitating removal of the cooling fluid tubes 30 for servicing activities. The rack cooling unit 1000 is compact and fits into rack 5 consuming less than 6U space, ensuring more available space for server equipment in the rack 5.
By using a backward curved centrifugal fan, the rack cooling unit 1000 of the present disclosure provides enhanced cooling efficiency. The cooling efficiency is further enhanced by using the inlet guide ring 106, which optimizes the mass of air sucked into and thus the mass of air circulated by the fan 107. The use of a radial-flow backward curved centrifugal fan gives the flexibility for mounting the indoor unit 10 at bottom or top or in the middle of the rack 5. Hence, the position of indoor unit 10 within the rack 5 that gives optimum cooling of the electronics stored in the rack 5, as per the distribution of heat generation along the rack 5.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a rack cooling unit that:
• provides high cooling efficiency;
• gives optimal air distribution;
• can be placed at any location within the rack; and
• incurs less operating cost.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components are omitted so as to not unnecessarily obscure the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.