DATA CENTRE, AND POWER AND COOLING SYSTEM THEREFOR
A data centre having a primary power source and a backup power source, wherein the primary power source comprises a gas pressure reduction station driving at least one generator, and the secondary power source comprises a large scale electricity distribution network.
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The present invention relates to a data centre.
BACKGROUND OF THE INVENTIONData centres are buildings where organisations choose to cluster their computers. The computers are held in a secure environment. In this context this means that environmental controls are applied such that the computers are adequately cooled, access to the computers is restricted, fire protection systems are provided, and continuity of electrical power is also ensured. Issues surrounding the provision of backup generation and cooling will be discussed further with reference to
In order to reduce the risk of disruption data centre owners install uninterruptible power supplies 20 which often include banks of batteries to provide short term power and standby generators running continuously or available at short notice so as to minimise start-up time. Even if the generator is not running it may be kept warm so as to facilitate a rapid start. Thus, such UPS systems 20 consume fuel, even under “no load” conditions. They do, however, ensure that the servers 4 can remain powered even if the national grid or a local part of it fails thereby preventing mains power being distributed from the power station 10 to the data centre 2.
The servers in the data centre are often quite densely packed, and deliberately so as high speed computing requires dissimilar computers to be located physically close to one another. As a consequence the servers generate significant amounts of heat which needs to be removed from the data centre by a computer room air-conditioning plant 30 which in reality is a refrigeration unit using chillers, compressors, heat pumps and the like as is well known to the person skilled in the art, to provide a chilled environment around the servers and to pump heat therefrom into the environment. This functionality needs to be maintained even when, for example, on a hot summers day the environmental temperature is greater than the target temperature inside the room containing the servers.
There is, of course, little point in maintaining power to the servers in the event of a failure of the main power supply 12 if cooling is not provided to the server room otherwise the servers would quickly initiate self controlled thermal shutdown in order to protect their components. Consequently the computer room air-conditioning unit 30 also has to be protected by the uninterruptible power supply 20.
SUMMARY OF THE INVENTIONAccording to a first aspect of the present invention there is provided a data centre having a primary power source and a backup power source, wherein the primary power source comprises a gas pressure reduction station driving a generator, and the secondary power source comprises a large scale electricity distribution network.
The inventors realised that the data centre power model could be “stood on its head” and the national grid used as the uninterruptible power supply with local power generation forming the primary source of power for the data centre.
According to a second aspect of the present invention there is provided a data centre in combination with a gas pressure reduction station, wherein cooling for the data centre is provided at least in part by the gas pressure reduction station.
The inventors further realised that, looking at the power budget for a data centre as a whole, around half of the electricity consumed by the data centre is used by auxiliary equipment, namely the computer room air-conditioning system, chillers, and the UPS system. Thus the overall power requirement of a data centre could be significantly reduced by placing it in proximity or conjunction with a gas pressure letdown station as the gas pressure letdown station causes gas to become chilled during the expansion process and significant amounts of heat are required by the letdown station in order to prevent undue cooling of pipes in the vicinity of the letdown station, possibly leading to damage of the pipes by ground heave, or the formation of deposits within the pipe as a result of impurities or moisture within the gas condensing out. Similarly the data centre requires large amounts of cooling therefore the data centre can provide the heat that is required by the gas letdown pressure reduction station and is so doing the pressure reduction station provides the cooling required by the data centre.
Advantageously the expansion of gas at the letdown station is performed by allowing the gas to expand in a turbo-expander such that the gas does mechanical work, and this mechanical work, such as rotation of a turbine, can be used to drive a generator thereby providing a source of electricity. The electricity can be provided to run electrical equipment within the data centre.
The present invention will further be described, by of non-limiting example only, with reference to the accompanying Figures, in which:
Reducing the gas pressure causes it to change its volume, and since the expansion process is essentially adiabatic the energy used to change the gas volume is extracted from the internal (thermal) energy of the gas and hence the gas temperature reduces. However since gas, such as natural gas used for fuel, is a complex mix of chemicals this may result in formation of ice or complex hydrates in and around the gas carrying pipes which can damage control valves of the gas distribution system or cause freezing of the ground around the pipe which again may cause damage.
As a consequence a typical gas pressure reduction station comprises an expansion unit 50 such as a turbo expander which is followed by a heat exchanger 52 such that heat can be delivered to the gas exiting the turbo expander 50 so as to warm it sufficiently in order to prevent the problems caused by excessively cold gas. The gas around the heat exchanger is quite cold, so the heat exchanger 52 can be regarded as a source of cold, or a source of cooling power.
The turbo expander 50 performs mechanical work and advantageously is connected to a generator 54 for generating, for example, three phase electricity which can be used to power electrical machines.
It can thus be seen that the gas expansion station 42 generates electricity by virtue of its generator 54 but also requires heat to be supplied to it. Conversely the data centre 40 requires electricity and is also a source of heat which has hitherto required the use of air-conditioning and refrigeration equipment which itself consumes electricity whilst extracting heat from the server environment and pumping it into the atmosphere.
The inventors noted that by combining a gas expansion station with or associating it with a data centre then some or all of the power requirements of the servers could be met by the electricity generated from the generator 54. Similarly the servers present a source of heat. The servers exchange their heat with the atmosphere surrounding them in the data centre and this can then be circulated by one or more fans 60 past one or more heat exchangers 62 of a cooling unit 65, of which only one is shown, which are in thermal connection with the heat exchanger 52. A transfer medium, such as a liquid or a gas, needs to be circulated inside the heat exchanger network and is driven around the heat exchanger network by a pump (not shown). Simplistically it has been assumed that the heat generation from the servers is sufficient to match the heat requirements at the gas expander. However, as we shall show later additional heating for the heat exchanger 52 can be provided from an internal combustion engine which may also be used as a source of primary electrical power in order to augment or top up the power provided by the generator 54. Similarly, it may be possible that due to load imbalances the heat generated by the servers, and possibly the result of other environmental factors effecting the data centre, might be in excess of the heat load required by the heat exchanger 52. Under such circumstances an otherwise conventional computer room air conditioning plant 70 can be brought into operation, with its power being provided either by the national grid as shown in
As shown in
The arrangement shown in
When considering the prior art case, the uninterruptible power supply is generally running on standby mode all of the time and has to provide sufficient power to run both the servers and the air-conditioning system 30. When the data centre is associated with a gas let down unit then the gas pressure reduction station is running continuously, except in the event of mechanical failure, and this allows for the national grid 12 to take the role of the uninterruptible power supply as there is a high probability that, at the time of a mechanical failure occurring in a turbo expander or generator of a letdown station, that the national grid will be running. Furthermore, where multiple letdown stations are provide in parallel then the chances of a fault effecting all of them becomes significantly reduced.
A heat exchange medium, such as a gas, is circulated between the heat exchangers 55, 52a, 52b and the computer room air conditioning equipment 65 of the data centre 40. The flow of the heat exchange medium from any of the heat exchangers 55, 52a and 52b is controlled by a valve system 58 which may incorporate electrically operated valves under the control of a computerised control system (not shown).
In the further arrangement, and as shown in
The ability to remove the standby UPS diesel set and battery set should not be underestimated. Even when the UPS is running on standby it is consuming power, and generating heat that may itself need to be removed.
As mentioned before, it may be necessary or desirable to augment the output of the generator 54 by a further generator 90 which is driven by an internal combustion engine 92. Heat from the internal combustion engine may be released to the environment via a conventional water based cooling system for such an engine or may be ducted towards any of the heat exchangers 94, 96 and 98 which may be provided in parallel, or series with controllable by-pass valves. Heat exchanger 94 allows heat from the engine to be added to the heat exchange fluid returning from the data centre computer room air conditioning unit 65, and from here it can be directed to any of the heat exchangers 55, 52a or 52b to warm the gas, with respective warming powers to the heat exchangers being controlled by the valves of the valve system 58.
Heat exchanger 96 allows heat to be delivered to an absorption chiller 98 (such devices being known to the person skilled in the art) which can further cool the heat exchange fluid via a heat exchanger 100.
Heat exchanger 98 allows heat to be delivered to a heat engine, such as an organic Rankin cycle engine 102 (known to the person skilled in the art) which drives a further generator 104.
Generators 54a, 54b, 90 and 104 can all deliver electrical power to the data centre 40, and excess power may be returned to the national grid. Frequency converters may be associated with each generator, but are also known to the person skilled in the art.
As part of its operation the internal combustion engine generates carbon dioxide. The carbon dioxide in the exhaust might be separated from the other exhaust components at a separation unit 110 and may then be purified and compressed by compressor 112 and stored in a tank 114. Suitable known carbon dioxide separation technologies include membrane technologies and pressure swing adsorption techniques. The carbon dioxide may, for example, be used as the heat exchange medium in the heat exchangers 52a, 52b and 65 as its escape into the environment would cause little harm (given that the carbon dioxide would otherwise have been released by operation of the internal combustion engine) and if escape of the carbon dioxide occurs within the server room, then as the server room is generally unmanned, it only serves to further reduce the risk of fire within the server environment.
Waste carbon dioxide from the engine might, for example, be ducted towards greenhouses where it is already known to grow plants in an enriched CO2 environment as this enhances their rate of growth.
Claims
1. A data centre having a primary power source and a backup power source, wherein the primary power source comprises a gas pressure reduction station driving at least one generator, and the secondary power source comprises a large scale electricity distribution network.
2. A data centre as claimed in claim 1, wherein the gas pressure reduction station is coupled to heat exchangers within the data centre, such that heat produced by computers or other electronic devices within the data centre can be used by the gas pressure reduction station.
3. A data centre as claimed in claim 1, wherein the gas pressure reduction station is connected to a cooling system of the data centre such that cold from the gas pressure reduction station is used to cool the data centre.
4. A data centre as claimed in claim 1, further including an internal combustion engine adapted to drive at least one of a generator and a compressor, and wherein carbon dioxide in the exhaust gas of the internal combustion engine is captured and cooled, and used as a heat exchange medium to cool the servers or as a fire suppressant in a server space.
5. A data centre as claimed in claim 4, further including an absorption chiller in combination with the internal combustion engine.
6. A data centre as claimed in claim 4, in which the internal combustion engine is diesel or bio-fuel powered.
7. A data centre as claimed in claim 1, in which a heat exchanger is provided downstream of an expansion engine in the gas pressure reduction station.
8. A data centre in combination with a gas pressure reduction station, wherein cooling for the data centre is provided at least in part by the gas pressure reduction station.
Type: Application
Filed: Jul 12, 2010
Publication Date: Jun 23, 2011
Applicant: 2OC Ltd. (Bristol)
Inventor: Edward L. Zakrzewski (Purley)
Application Number: 12/834,151
International Classification: F25B 27/02 (20060101); F25B 41/00 (20060101); F25D 31/00 (20060101);