Patent Application
20120156981
1. Field of the Invention
This invention relates to variable dampers that regulate air flow through passageways, such as grates. The dampers are positioned in or adjacent the passageways and have one or more members that selectively and variably block air passing through the passageways.
2. Background of the Invention
There are certain environments in which it may be desirable to regulate the air flow through a passageway such that different volumes of air are permitted to pass through different zones of the passageway. One such environment is a data center, and the subject passageway is an access floor grate panel in the data center, as discussed below.
A typical data center includes multiple IT racks. The equipment supported by those racks, and the associated cables and other accessories, generate a relatively high amount of heat. Because of that heat, providing adequate cooling to IT racks in the data center is of paramount importance. Moreover, it is desirable that the IT racks be cooled as efficiently as possible, as the energy costs to cool IT racks may approach a large percentage of the energy costs to operate the data center.
Data centers typically have a raised floor system, often called an access floor system. An access floor system is usually comprised of a continuous array of floor panels, arranged edge-to-edge, and supported above the sub-floor by support structure. The array of access floor panels usually extends wall-to-wall in the data centers.
A plenum is formed between the sub-floor and the access floor panel array. Cables, wires, hoses, etc. are located in the plenum, and the plenum is also used as a conduit for cooling air. Often, one or more air conditioning units supply air to the plenum, and some of the access floor panels in the access floor panel array have grates. The cooling air passes through the grates into the data center.
The access floor panels with grates are usually positioned immediately adjacent to IT racks, and may have vanes that direct the cooling air that passes through the grates toward the IT racks.
A typical IT rack supports a variety of electronic equipment. The equipment is often unevenly distributed throughout the rack, including vertically. In that regard, an IT rack may have shelves, spaced vertically. Different equipment may be placed on the different individual shelves.
Different IT equipment generates different amounts of heat. Thus, the heat generated by the equipment at one vertical height of an IT rack (e.g., on one shelf) may differ from the heat generated by the equipment at another vertical height of the same IT rack (e.g., on a different shelf). However, the prior art IT rack cooling apparatus does not take into account that difference in heat at the various heights. Rather, usually there are temperature sensors at various locations of an IT rack, and the volume of cooling air is determined for the whole rack based on the readings of those sensors. In fact, often the volume of cooling air for the entire rack is based on the highest sensed temperature in the IT rack. That is, the entire IT rack is subjected to the volume of cooling air necessary to cool the hottest area or zone in the rack, even the areas or zones of the rack that are already much cooler than the hottest area or zone.
This results in inefficient cooling of the IT racks, because the cooling air is directed at the same volume to all areas of the IT rack based on the highest temperature in the rack, even to those areas that may need little, if any, cooling. More efficient and economical cooling would be achieved if larger amounts of cooling air are directed to the hottest areas of the IT racks, while lesser amounts of cooling air are directed to the other, cooler areas of the IT rack. Thus, in a data center, there is a need for cooling apparatus that directs different amounts of cooling air to different areas of or zones in the IT racks in the data center.
The multizone variable damper of this invention addresses that need, as well as the need in other environments for apparatus that selectively regulates the flow of air in different zones of a passageway.
A multizone variable damper according to one embodiment of this invention includes two or more air passageway zones defined by movable members, wherein the positions of the movable members determine the air passageway openings in each of the passageway zones. The movable members are movable relative to each other such that the sizes of the air passageway openings in the passageway zones can be varied relative to each other. This embodiment also includes actuators that move the movable members relative to each other.
In certain embodiments, the movable members are pairs of opposed blades, with one of the pairs of opposed blades being located in each air passageway zone. The blades may extend lengthwise, and the air passageway zones may be aligned edge-to-edge widthwise.
The actuators can be manual or “automatic.” The “automatic” actuators may move the movable blades based on predetermined conditions (e.g., time of day) or sensed conditions (e.g., temperature or pressure differential).
Before describing the multizone variable damper of this invention, one environment in which it may be utilized is first described. The environment is a data center that includes one or more IT racks. That environment is illustrated, in part, in
In
IT rack 30 supports a variety of IT equipment. The heat generated by the equipment supported by IT rack 30 may vary in different areas or zones of IT rack 30 for many reasons, including the following. First, different types of IT equipment generate different amounts of heat. Second, the equipment may be unevenly distributed in IT rack 30, in all three dimensions, including vertically, laterally and longitudinally. Third, different units or assemblies of the equipment may operate at different times of the day. All of those factors may result in zones of different temperatures in IT rack 30 at any given time. For example, in
To achieve the most efficient and economical cooling of IT rack 30 when it has zones of different temperatures, such as zones 31a, 31b and 31c, it is desirable to supply or direct different volumes of cooling air to the different zones, so that each zone is cooled by the minimum necessary amount of cooling air. Thus, taking
This invention achieves that goal, as discussed in detail below.
The embodiment of this invention illustrated in the Figures is multizone variable damper 10. In
Multizone variable damper 10 is illustrated in more detail in
In the embodiment illustrated in the Figures, the multizone variable damper 10 defines three zones: zones 21a, 21b and 21c. The number of zones is not limited to three, but can be more than three zones and as few as two zones.
The zones 21a, 21b and 21e are positioned such that air that passes through each zone is directed, by grate panel 32, to a specific zone in IT rack 30. In this embodiment, the air from zone 21a is directed to IT rack zone 31a, the air from zone 21b is directed to IT rack zone 31b, and the air from zone 21c is directed to IT rack zone 31c. See
Also in the embodiment illustrated in the Figures, each zone has a pair of opposed blades that move relative to each other to control airflow through that zone. Specifically, opposed blades 30a are in zone 21a, opposed blades 30b are in zone 21b and opposed blades 30c are in zone 21c. The blades 30a, 30b and 30c can be made of any material that is capable of providing the structural rigidity required for a given application. Preferably, the blades 30a, 30b and 30c are made of metal.
Opposed blades 30a, 30b and 30c extend the length of multizone variable damper 10, and the zones 21a, 21b and 21e are located serially along the width of multizone variable damper 10.
As shown in
While the embodiment illustrated in the Figures utilizes pairs of opposed blades 30a, 30b and 30c to regulate the amount of air that passes through each zone 21a, 21b and 21c, respectively, any other means for variably regulating air flow through zones 21a, 21b and 21c can be used in place of opposed blades 30a, 30b and 30c, including single blades. However, one advantage of using a pair of opposed blades instead of a single blade is that the pair of opposed blades does not interfere with the directional nature of grate panel 32 if grate panel 32 is a directional grate.
In this embodiment, the multizone variable damper 10 includes actuators 20a, 20b and 20c, which are provided for each pair of opposed blades 30a, 30b, and 30c, respectively. The actuators 20a, 20b and 20c rotate the pairs of opposed blades 30a, 30b and 30c to their desired positions. The actuators 20a, 20b and 20c can either be manually operated or can be automatically operated.
There is a wide variety of manual actuators that can be used to rotate the blades of pairs of opposed blades 30a, 30b and 30c, including a lever (not shown) that is rotatable between fully closed and fully opened positions, and all positions between those two extremes. The lever is connected by a link or a series of links to a member that rotates the pair of blades. When the lever is in a first position, the rotatable member positions the pair of blades in the completely closed position. When the lever is rotated to a second position, the rotatable member is rotated to position the pair of blades in the completely open position.
There is also a wide variety of “automatic” actuators that can be used to rotate the blades of pairs of opposed blades 30a, 30b and 30c, including motors that rotate the blades in accordance with signals or instructions from a control unit. The control unit may instruct the movement of the blades based on a sensed condition, or a predetermined condition such as by the time. An example of a control unit that is responsive to a sensed condition is illustrated in
In
In the embodiment illustrated by
The temperature data from sensors 80a, 80b and 80c is used to adjust the positions of the blades of pairs of blades 30a, 30b and 30c so that the minimal necessary cooling air is directed or supplied to the IT rack zones 31a, 31b and 31c. Examples are discussed below, with reference to
In
In
As can be determined, blades 30a, 30b and 30c can be positioned relative to each other in any manner dictated by the respective temperatures in IT rack zones 31a, 31b and 31c.
As stated, in this embodiment, the control unit 110 controls the actuators 20a, 20b and 20c based on temperatures in the respective IT rack zones, zones 31a, 31b and 31c. In other embodiments, the control unit 110 may receive and act on pressure differentials in the various zones, for example at the back face of the IT rack 30, instead of the temperatures.
Further, in other embodiments, each actuator 20a, 20b and 20c may be operated by a separate control unit dedicated to it. That is, instead of a single control unit 110, there is a separate control unit for each actuator 20a, 20b and 20c. Those individual control units receive information from the corresponding IT rack zones and provide instructions to the corresponding actuators. For example, an individual control unit for actuator 20a would receive the temperature data from sensor 80a and instruct actuator 20a accordingly, the control unit for actuator 20b would receive the temperature data from sensor 80b and instruct actuator 20b accordingly, and the control unit for actuator 20c would receive temperature data from sensor 80c and instruct actuator 20c accordingly.
By providing three or more zones, the multizone variable damper 10 of this invention allows for precise cooling of the IT rack 30 based on sensed conditions along the height of the IT rack 30.
What has been described and illustrated herein are preferred embodiments of the invention along with some variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims—and their equivalents—in which all terms are meant in their broadest reasonable sense unless otherwise indicated.
