REDSHAW, Stuart, Peter (The Willows, Redhill LockRatcliffe on Soar, Nottingham NG11 0EB, GB)
TINDALE, Patrick (Ruddington House, 13 Kirk LaneRuddington, Nottingham NG11 6NN, GB)
REDSHAW, Stuart, Peter (The Willows, Redhill LockRatcliffe on Soar, Nottingham NG11 0EB, GB)
| CLAIMS 1. A portable measurement apparatus comprising: - a plurality of air measurement units, each unit comprising a tapering duct extending between an inlet and an outlet of the unit, an anemometer disposed at the outlet and a temperature sensor arranged to measure temperature of air passing through the duct; and - a data processing unit connected to, and configured to receive and store readings from, each of the anemometers and temperature sensors, wherein the air measurement units are arranged to form, in use, a vertical array for measuring air flow through each of the units. 2. The apparatus of claim 1 wherein the inlets of the air measurement units are aligned along a side face of the apparatus for measuring air flowing in a horizontal direction through each air measurement unit. 3. The apparatus of claim 1 or claim 2 comprising a further air measurement unit arranged to measure air flow in a vertical direction through the apparatus. 4. The apparatus of claim 1 wherein the air measurement units are removable from the apparatus and configured to be interchangeable to allow for a plurality of different arrangements of vertical arrays. 5. The apparatus of claim 1 wherein the air measurement units are collapsible from an extended state in which the tapering duct is formed between the inlet and outlet and a collapsed state in which the inlet and outlet are brought closer together. 6. The apparatus of claim 5 wherein the tapering duct is composed of a flexible fabric material. 7. The apparatus of claim 5 wherein the tapering duct is composed of a plurality of hinged panels. 8. The apparatus of claim 1 wherein the air measurement units are removable from the apparatus and configured to be stacked together when removed from the apparatus. 9. The apparatus of claim 1 wherein the apparatus comprises a foldable frame configured to support the air measurement units and the data processing unit in use and to collapse to a reduced size in a stored state. 10. A method of analysing air flow in a data centre, the method comprising: i) providing a portable measurement apparatus according to any one of claims 1 to 9; ii) positioning the apparatus adjacent an operational unit of electronic equipment; iii) receiving and storing readings from each of the anemometers and temperature sensors in the data processing unit; and iv) repeating steps ii) and iii) for each of a plurality of units of electronic equipment in the data centre. 11. The method of claim 10 wherein the stored readings are processed to obtain measurements of air mass flow rates through each of the plurality of operational units of electronic equipment. 12. A portable measurement apparatus substantially as described herein, with reference to the accompanying drawings. 13. A method of analysing air flow in a data centre substantially as described herein, with reference to the accompanying drawings. |
The invention relates to measuring air flow in ventilated environments such as computer data centres, and to apparatus for carrying out such air flow measurements. Modern data centres typically comprise racks of electronic equipment such as computer processors, memory, storage and servers in an enclosed and secured environment. The large amounts of heat generated by such equipment needs to be removed to avoid overheating. A common way of transporting this waste heat is by forced air cooling, where air is passed through each equipment rack to cool the equipment inside. More efficient ways of removing heat are possible, such as liquid cooling, but forced air cooling is preferable in many cases due to the flexibility of being able to easily reconfigure, remove and replace individual components.
Air cooling in data centres typically involves supplying an entire room, or series of rooms, with air via the floor or ceiling of the room, for example by using an underfloor cavity or plenum to supply cooling air to the room in which electronic equipment racks are located. Air is directed to each equipment rack via perforated floor tiles located adjacent racks that require cooling. Heated air that has passed through the equipment racks can be removed via an exhaust system, for example using perforated ceiling tiles and a ceiling space. Air may be recirculated through the data centre by passing at least a portion of it through one or more air handling units, which may be configured to cool air passing through them. Alternatively, free air cooling, i.e. using cooling air from the external environment, may be used if the external air temperature is sufficiently low to provide adequate cooling, thereby saving on air conditioning energy usage.
A problem with air cooling in data centres is how to optimise the distribution of air throughout the data centre, particularly when the cooling requirements of different racks of equipment may be different, given different power requirements. Hot and cool areas will tend to arise, due to the arrangement of equipment racks, as well as the position and flow rates of the air handling units, the positioning of floor tiles and any obstructions in the air flow path. The problem of how to predict where air will flow within a data centre is consequently complex, and not easily solved by trial and error alone.
Computational fluid dynamics (CFD) software may be used to assess air flow within a data centre, the results of which can be used to make adjustments to the air flow, for example by moving equipment racks or floor tiles, or by adjusting the flow rates of air handling units. To be able to run such CFD programs, data generally needs to be provided on the current state of the data centre, which can be provided from temperature measurements taken across the room. This type of thermal analysis and optimisation, combining thermal measurements with CFD is used in, for example, an IBM system known as Mobile Measurement Technology (MMT), in which a cart is configured to take temperature measurements at various heights over each floor tile within a data centre. These temperature data are fed into a CFD model, together with data on air flow and power consumed by the equipment in the data centre, to determine how much air flow is provided to each equipment rack.
A problem with existing approaches to analysing and optimising air flow is that the indications of power used and air flow provided may be inaccurate. It may also not be possible to take actual power measurements on each rack without causing significant disruption to the operation of the data centre, which typically cannot be taken offline. Such thermal surveys may also be time-consuming, difficult and complicated to carry out fully, which is a further disadvantage if further surveys are required after adjustments have been made.
US 2009/0041079 discloses a tool for measuring the thermal characteristics of a unit of electronic equipment, in which an air pressure sensing element is located in a duct, an edge of the duct having a band of bristles that contacts the tool with the surface of a unit to be measured. Performing measurements of the thermal characteristics throughout a data centre comprising many racks each comprising multiple units would, however, be impractical and very time-consuming using such a tool.
It is an object of the invention to address one or more of the above mentioned problems, and in particular to allow for surveys of data centres to be carried out more effectively and efficiently. In accordance with the invention there is provided a portable measurement apparatus comprising:
- a plurality of air measurement units, each unit comprising a tapering duct extending between an inlet and an outlet of the unit, an anemometer disposed at the outlet and a temperature sensor arranged to measure temperature of air passing through the duct; and - a data processing unit connected to, and configured to receive and store readings from, each of the anemometers and temperature sensors,
wherein the air measurement units are arranged to form, in use, a vertical array for measuring air flow through each of the units.
An advantage of the invention is that configuring the measurement units in a vertical array allows for a mass flow rate of air to be measured over the height of the measurement apparatus, with a minimal disruption of the air flow being measured. A measure of air flow and temperature for each equipment rack in a data centre can therefore be taken more quickly using the apparatus.
The inlets of the air measurement units are preferably aligned along a side face of the apparatus for measuring air flowing in a horizontal direction through each air measurement unit. Since air flowing to or from a rack of electronic equipment will tend to be aligned in a mainly horizontal direction, at least in a region close to the rack, aligning the units in this way allows for a reasonably accurate measure of air flow being provided to, or output from, a relevant rack, without the need to interface directly with, and possibly thereby interfere with, the equipment in the rack itself. The apparatus may comprise a further air measurement unit arranged to measure air flow in a vertical direction through the apparatus. This further air measurement unit could, for example, be configured to measure air flowing through a perforated floor tile over which the apparatus is positioned. The air measurement units may be removable from the apparatus and optionally configured to be interchangeable to allow for a plurality of different arrangements of vertical arrays. Different arrangements of vertical arrays may, for example, be used to match the size and arrangement of output air vents of a stack of electronic equipment, or to provide different resolution of air flow measurements at different heights.
The air measurement units may be collapsible from an extended state in which the tapering duct is formed between the inlet and outlet, and a collapsed state in which the inlet and outlet are brought closer together. This may for example be achieved by having the tapering duct composed of a flexible fabric material, or alternatively by having the tapering duct composed of a plurality of hinged panels. The air measurement units may be removable from the apparatus and may be configured to be stacked together when removed from the apparatus, thereby saving space when the apparatus is not in use. The apparatus may comprise a foldable frame configured to support the air measurement units and the data processing unit in use and to collapse to a reduced size in a stored state, thereby saving space when the apparatus is not in use and making the apparatus more readily transportable. According to a second aspect of the invention there is provided a method of analysing air flow in a data centre, the method comprising:
i) providing a portable measurement apparatus according to the first aspect;
ii) positioning the apparatus adjacent an operational unit of electronic equipment; iii) receiving and storing readings from each of the anemometers and temperature sensors in the data processing unit; and
iv) repeating steps ii) and iii) for each of a plurality of units of electronic equipment in the data centre.
The stored readings may be processed to obtain measurements of air mass flow rates through each of the plurality of operational units of electronic equipment, or alternatively may be stored as raw data readings for later processing and analysis.
Exemplary embodiments of the invention are described in further detail below with reference to the appended drawings in which:
figure 1 is a front perspective and side elevation view of an exemplary portable measurement apparatus;
figure 2 is an alternative perspective view of an exemplary portable measurement apparatus;
figure 3 is a perspective view of the portable measurement apparatus of figure 2, with the air measurement units removed;
figure 4 is a perspective view of the portable measurement apparatus of figures 2 and 3, with the air measurement units removed and stacked and with the apparatus is a partially folded state; and
figure 5 is a perspective view of the portable measurement apparatus of figures 2- 4, with the apparatus in a fully folded state. Figures 1 and 2 illustrate different views of an exemplary portable measurement apparatus 10. The apparatus 10 comprises a plurality of air measurement units 11 a-e, each unit 11 a-e comprising a tapering duct 12 extending between an inlet 13 and an outlet 14. Each air measurement unit is generally in the form of a hollow cone, a wider end of the cone forming the inlet and a narrower end forming the outlet. An anemometer 15 is disposed at the outlet 14 of each tapering duct 12. A temperature sensor 16 is also arranged within each duct 11a-e to measure the temperature of air passing through the duct 11a-e. The apparatus 10 also comprises a data processing unit 17 that is connected to, and configured to receive and store readings from, each of the anemometers 15 and temperature sensors 16. The data processing unit 17 may for example be a computer with a data logging card for capturing the temperature and pressure data obtained from the temperature sensors 16 and anemometers 15, the computer processing the received data into a form suitable for use by a further program such as a CFD model. Location data is also preferably logged, to allow the temperature and air flow data to be input into a model of the data centre. The data processing unit 17 may alternatively be a logging and storage device, and any processing can be carried out after the raw data has been acquired by transferring the data to a computer for processing.
The air measurement units 11a-e are arranged in a vertical array for measuring air flow through each of the units. The inlets 13 of the air measurement units 11a-e are also aligned along a side face 19 of the apparatus 10 to allow for measuring air flowing in a horizontal direction (indicated by arrows 18) through each air measurement unit 11a-e.
The apparatus 10 may comprise a further air measurement unit (not shown), arranged to measure air flow in a vertical direction through the apparatus. The further air measurement unit may, for example, be of a similar form to the vertically-arranged units 11a-e, but with the inlet 13 parallel with the floor of the data centre and configured to measure air flow through a floor tile over which the apparatus 10 is positioned The apparatus 10 preferably comprises wheels 20, for example in the form of castors, to allow the apparatus 10 to be easily moved around and positioned in a data centre as required. A location sensing module may be provided to enable a measure to be logged of where the apparatus is at each measurement point. In an embodiment, the apparatus may be programmed to move itself around a pre-prepared plan of a data centre, taking measurements at a series of predetermined locations. 00902
The anemometers 15 may be of a type that measures relative air pressure, from which air velocity through the units 11a-e can be derived. From this, a velocity measure of air flow entering the units 11a-e can be derived, with knowledge of the dimensions of the units 11a-e and assuming that the apparatus has a minimal effect on actual air flows. From these velocity measurements, mass flow rates of air can also be derived and, in combination with temperature of the air passing through the ducts of the units 11a-e, a measure of heat flow can be obtained.
The air measurement units 11a-e may be removable from the apparatus 10, as shown in figure 3 in which the units are shown separated from a support frame 31 of the apparatus 10. The air measurement units 11a-e, which in figure 3 are all the same size, may be configured to be interchangeable to allow for a plurality of different arrangements of vertical arrays. For example, an array of air measurement units 11a-e having a reduced height may be used to obtain a higher vertical resolution of air flow.
The air measurement units 11a-e may be collapsible from an extended state in which the tapering duct 12 (figure 1) is formed between the inlet 13 and outlet 14 and a collapsed state in which the inlet and outlet are brought closer together. This may be achieved for example by the tapering duct being composed of a flexible fabric material, or a plurality of hinged panels. In the former case, the air measurement units may be held in an opened configuration by struts extending between the outer edge of the inlet and the outlet.
As shown in figures 4 and 5, the air measurement units 11a-e may also be configured to be stacked together when removed from the apparatus 10, thereby reducing the volume taken up by the apparatus when not in use. To further reduce the volume, the frame 31 of the apparatus 10 may be foldable and configured to support the air measurement units and the data processing unit 17 in use and to collapse to a reduced size in a stored state. Figure 4 illustrates the foldable frame 31 in a partially collapsed state, and figure 5 shows the frame 31 in a completely collapsed state. In the collapsed state the apparatus is more easily transported, and would typically be of a size comparable with a large briefcase.
The apparatus, in particular the data processing unit, is preferably battery powered, to allow for wireless operation. Wireless Connectivity may be used for data download or transfer from the data processing unit to a computer system for further analysis of the data acquired, for example as input data for a CFD model. The apparatus may be configured to detect a distance between at least the side face 19 (figure 1) and an object such as an equipment rack the apparatus is positioned adjacent. This may be achieved by using a laser-based room surveying tool. The apparatus may also be configured to take and store a photographic or video record of a data centre survey, and to store this data together with the air flow measurement data in the data processing unit.
The apparatus is preferably no wider than 600mm, which is the standard width of a data centre floor tile, so that the apparatus can be used in most conventional data centre environments.
The apparatus may comprise a depth meter such as a downward-looking laser to enable measurements to be taken of the depth of an underfloor plenum over which the apparatus is used. A drop down probe may also be used to measure temperature, air flow and humidity below the floor of the data centre.
While measurements are being taken, the apparatus is preferably configured to automatically apply brakes to the wheels to ensure that the apparatus remains immobile during measurements.
Other embodiments are intentionally within the scope of the invention as defined by the appended claims.
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