Three pillars data-center engineering infrastructure leans on
Data-center of high level of reliability is a complex object, for the vital activity of which a well-coordinated work of electricity supply system, cooling and conditioning, scheduling and monitoring is required. On the 9th international conference «Data Centers — 2014», organized by the magazine «IKS» they talked about new achievements in those areas.
Flexibility and versatility again
The scalability of the data-center electricity supply system provides the possibility of its development in the future. It is not surprising that for electricity supply system of high power, notably those are required for data-centers today, modular architecture has become standard de facto.
Extremely indicative in this sense is three-phase static uninterruptible power supply (UPS) Trinergy Cube, in which designers of Emerson Network Power Company have embodied the idea of three-dimensional modularity. Modularity in horizontal direction means scaling of one system from 300 kWh to 3 MWh, achieved by adding power packs. Vertical modularity is a possibility to replace one of these modules without stopping the system as a whole. And, finally, orthogonal modularity allows parallel connection of up to eight systems to increase the total capacity to 24 MWh. So, the epithet «Cube» is present in the title of this system not only because it is the third top-of-the-line model in the family of three-phase uninterruptible power supply systems Trinergy, but also because of its three-dimensional modularity. By the way, there are also three dynamic modes, which operate the UPS. In addition to the standard mode of double transformation (VFI), the system, by analyzing the parameters of the supply net may switch to power save mode (VFD) in which it operates with efficiency more than 99%, or in the mode VI in which high efficiency (98.5 %) is combined with the stabilization of the voltage characteristics.
In contrast to the appeared a few years earlier entry-level models, Trinergy Cube is able to adapt to the environment temperature. For example, at a temperature of + 40 C°, wherein all Emerson systems are certificated to the primary minimum power capacity, the capacity of one power module is 250 kVA, and when the temperature drops to + 20-25 C° up to 400 kVA can be removed from the power module. Thus, warranting a certain temperature range on the basis of Trinergy Cube it is possible to construct a compact solution. In order to offer designers and data-center developers a system for growth, its central switching module was also endowed with the ability of reconfiguring the power. A special configurator allows collecting UPS, which characteristics meet the needs of present-day data-centers and can be expanded in the future under the principle of «Lego».
Three-phase UPS of TLE series of General Electric company give the opportunity to save space, reserved in the data center for uninterruptible power systems. Due to the fact that for the maintenance of these systems it is necessary to have only front-end access to them, they can be compactly placed wall to wall. The range TLE includes devices with 160-800 kVA capacity, plus the sources with capacity of 600 and 800 kVA entered the market in Y2014. Increasing of capacity of uninterruptible power supply (UPS) of General Electric is allowed by its architecture, which provides parallel connection of up to six devices. In terms of double transformation the coefficient of efficiency of the UPS equals to 96.5%, while in economy mode eBoost it is 99%.
Uninterruptible power supplies of TLE series were found by the designers in the scale of container data-center Power MOD. This turn key solution is collected in accordance with international standards (10 ft «/ 20 ft» / 40 ft «). In addition to UPS of TLE series with the capacity of 200 kVA / 400 kVA / 2h 400 kVA / 3h× 400 kVA it contains rechargeable batteries of VRLA type, input / output connectors, an external service bypass, cooling systems and systems of remote monitoring. Systems of fire extinguishing, access control and video surveillance are available optionally. Despite its novelty, the containerized data-centers have already been used at the recent Winter Olympic Games for the backup of power supply on five Railway stations, in Sochi Adler airport and also on the main railway station of Sochi.
Moving the object to the system of high-voltage direct current (400 V) can impact additional flexibility and efficiency to the data-center power system. Advantages of using direct current systems in the data-centers are obvious. The number of alterations of electric current in such systems is smaller and hence power losses are smaller. Due to the simplicity of its design (e.g., they do not have inverters, which can fail), total cost of ownership (TCO) of the direct current system is low in comparison with the classic three-phase uninterruptible power supply (UPS). As of today, the whole range of necessary equipment, from direct current (DC) power systems to power distribution devices and connectors for the implementation of this approach is available. This trend is supported by many suppliers of IT equipment: HP, IBM (separate server lines), Juniper, Huawei. Marek Szpek, Business development Manager for Emerson Network Power in EMEA, in addition to Emerson, as one of the suppliers of DC power systems, mentioned also ABB, Eltek and Delta, noting that the last is still in the experimental stage of the development.
Emerson Network Power itself, whose commercial DC systems 400 Volt with capacity of 30 kW are actively tested by telecom operators all around the world: in Japan it is operated by telecom operator NTT DoCoMo, released one more, the most powerful model NetSure 9500 this year. Constructed on the proprietary rectifiers of own design, the system of power supply of high-voltage direct current has a modular design, which allows to use different configurations of deployment and to scale it by avoiding downtime of capacity and working areas. It includes a power supply module with sections of power conversion (depending on the required capacity, it can unite from 8 to 15 rectifiers), management and distribution of power, module for advanced load distribution and battery case, containing group of VRLA batteries. Possibility of hot changeover of rectifiers and control elements of this system reduces downtime.
Dmitri Kovalenko, Director of Sales FIAMM Industrial RUS Ltd is convinced that a key element of any UPS is batteries. TIA-92 standard recommends to use airproof maintenance-free batteries, manufactured by VRLA technology: acid airproof batteries with control valves in data-centers. These batteries are relatively cheap and in compliance with the operating conditions are reliable enough.
At the same time, as noted by Dmitry Kovalenko, a significant disadvantage of acid airproof batteries is reduction of life cycle in case of violation of conditions of usage, e.g. under non-compliance of conditions of temperature in the quarters, high or low charge voltage, overcharge and overshoot of the working cycle, in case of manufacturing defects and errors in the storage and implementation, and moreover well as the heterogeneity of indexes of individual elements in the range.
As an alternative to VRLA batteries high-temperature nickel sodium chloride batteries can be considered. They retain their performance characteristics in the range from −40 ° to + 65C ° and don’t require placement in conditioned rooms, have high energy density (more than 90 watt-hour/ kg), 70% lighter and 30% smaller than lead-acid batteries. Whereas the nickel sodium chloride batteries can be in any number of connected in parallel, increasing their capacity, they can be the basis for the construction of modular solutions. Furthermore, despite of the fact that such batteries are completely maintenance-free, communication ports for remote monitoring are built-in them.
In case of nickel sodium chloride batteries FIAMM SoNick, they are equipped with BMS active system that controls the temperature inside the battery and the process of its charge, checks the input / output electric parameters, disconnects the battery when operating parameters reach extreme point in order to avoid mortality and moreover it generates emergency signals.
It is clear that the cost of such intelligent and high-tech batteries is several times higher than of traditional VRLA, however, according to D. Kovalenko, their use can spare by refusal to condition space for batteries and lengthening the service life of the battery. Besides, nickel sodium chloride batteries are space-saving and occupy space three times smaller than the lead-acid battery of the same capacity in the data-center.
The question of the choice of strategy
A separate item of cost in the construction of data-centers is cable infrastructure. The present day, many data-center designers choose broadband traffic 40 and 100 GB / s, said Kevan Sproston, manager of Strategic Technologies Division Product Brand-Rex. It is facilitated by such factors as penetration into the corporate sphere of mobile solutions, virtualization of desktops and applications, and consumerization, suggesting that the employees of the companies want to have access to corporate data with the same high speeds as well as at home. And if the experts talked about the absence of applications which required data transmission rate of 1 GB / s ten years ago, now 40 GB / s can surprise nobody.
Whereas the lifetime of cable infrastructure is pretty big (experts estimate it as nine years), a temptation to move to higher categories of copper cables appears. However, we must realize that in 5-7 years more efficient solutions will enter the market and then structural cable system (SCS) will need to be upgraded. For example, today a network of 10 GB/ s, based on the cable of Category 6A is cheaper than the one that uses twisted pair of 7 or 7A category. Soon cable category 8 is anticipated, it will allow to immediately develop a network with a data transfer rate of 40 GB/ s. Investments in cable infrastructure have a long payback period, therefore it makes sense to choose the most updated categories of cable for data-centers.
Forewarned — means alerted
«Power property» or more exactly problems in it, not very often but can become a cause of fire. Herewith the concentration of smoke in the server rack can remain small, not more than 0.01% for a few days. In the judgment of technical director of «Fire Engineering» group of companies Igor Neplohov, it is not easy to find out such a smoke formation, as the airflow raised in the datacenter by air conditioning system, prevent the accumulation of smoke under the ceiling. So the smoke detectors, which are installed under the ceiling in order to prevent the occurrence of smoke, can carry this function out only if the ventilation system is turned off, and such happens infrequently.
The results of the tests, conducted by the company «Fire Engineering» revealed that to respond to a lighted smoke bomb, such devices require more than 220 seconds. As an alternative to them, the Company recommends to use a new laser aspirated smoke detectors VESDA in the data — centers, as they showed much better results. To protect small areas (up to 100 square meters) aspiration detector VESDA VLQ, which is installed on the ceilings should be used. For more spacious control rooms the senior model VESDA E, one block of which has 120 address tubes for trapping smoke will be more effective.
In the opinion of experts, application of modern means of early detection of fire in the data — centers is very important. It allows avoiding both direct damage from data loss and loss of equipment and collateral damage: downtime of the object, a breach of contract with customers, a decrease in the efficiency.
Adiabatic cooling in the trend
Whereas the struggle for the improvement of energy efficiency of data — centers has not been canceled, but on the contrary, according to the requirements of the Federal Law № 261, by Y 2020 the efficiency of electricity consumption in the country is expected to grow by 40%, as the reserve for energy savings cooling system and conditioning are treated frequently now. And there is no wonder: experts estimate their share in the total energy consumption of the data center in 35-45%.
Meanwhile, owners and designers in the West operating data centers, who never refuse the opportunity to save money and who always watch their money, with ever increasing frequency combine free cooling (natural cooling) with finely atomized cooling water, which is called adiabatic. According to open sources, this method, which provide 95% energy savings on cooling system for some objects, is started to be added to data centers constructors’ armory. As an example we can take the company DataPro, which has applied this approach in its data center in Moscow.
Appearance of the equipment in which the function of adiabatic cooling is available on the Russian market immediately from several global providers of such systems says that «things started happening».
Thus, the Company STULZ offers a modular high-density cooling system for outdoor installation CyberCon. Enclosed in the separate container, the system can be installed in the upper part of the room or container with IT equipment and supports four modes of operation: free cooling, adiabatic natural cooling, mixed and DX-mode.
When the temperature outside is in the range between a given inlet air temperature and temperature of frost protection, the outside air damper is opened, air flows through the filter unit and from there to the data center. With decreasing outdoor temperature or thermal forcing, the dampers of recirculating and outdoor air open, the right temperature of inflow is regulated as a result of their mixing. Organized in this way, the natural cooling can save up to 80% of electricity. If the outdoor air temperature is above the setpoint temperature of the inflow, adiabatic cooling system intervenes in the proceedings. It cools outdoor air to the claimed temperature, after this, the outside air damper opens and the system returns to the natural cooling mode. In both modes air supply setting is still turned off. It is switched on to support the natural cooling in mixed mode, the need for which arises in the further increase of the outdoor temperature. In this case, the compressor operates in the partial load mode. And finally, if the outdoor temperature is higher than acceptable in mixed mode, the outside air dampers are closed and CyberCon completely convertes to the compressor DX-mode.
Thus, the use of adiabatic cooling in this facility allows to extend the range of temperatures for using free cooling, improves its efficiency, and simultaneously regulates air humidity at the facility.
The Company Emerson introduced several new products this spring. One of them is a highly efficient module of indirect air free cooling with adiabatic cooling Liebert EFC. Equipped with EC- aspirator with low power consumption and noise intensity, and being under control of a special controller iCOM, the system can operate in four modes. In Russian conditions, the maximum use of each of these modes accounts for a certain time of the year. Thus, in winter the main load falls on the fans and the controller (DX mode), in spring and autumn the module operates in free cooling mode, in summer at temperature above 20C ° and low air humidity adiabatic cooling is added to it. In the case of peak loads — high temperature — the system goes into combination drive (the so-called mechanical backup mode).
The company NordVent also has its own conception of work of seasonal nature, which embodies it in the hull adiabatic air conditioning Mirage, designed to cool data centers. When fully consumed electric power of 11.2 kW cooling capacity air conditioner is 100-120 kW, due to the fact that it is built on the principle of indirect free cooling, which in combination with indirect adiabatic cooling for most of the year is used to produce dispersion data center heat. Its designers followed the recommendations of ASHRAE 2011, which admit the increase of the inlet air temperature till 27С°. Working three of four seasons a year adiabatic system of air conditioning is comprised of the selection of three-part injectors of high-quality steel which are stable for demineralised water. In the process of indirect adiabatic water cooling, the water is spraying on the side of the air extraction system, on the principle of hollow cone, cooling air and than the air make its way to plate recuparator, sertificed by EuroVent, for heat exchange.Corrosive steadiness of the last is provided by epoxy coat.
In competitive activity of climate control systems leading suppliers, whose solutions support the same technologies and have similar specifications, the choice of equipment for the construction of data center is very complicated for the owners. The recommendations of the participants of the process, designers, who are not interested in promoting specific solutions of certain vendor are quite appropriate in the situation.
Thus, CEO of «AMD Technologies» Maxim Sokhan believes that you should start with the competition of circuit design of the object concepts. In the Russian market there are no such competitions at all, and yet at this stage it is possible to save money. According to the experience of «AMD Technologies» you can reduce capital expenditures by almost half at this stage. The second recommendation of the expert regards the choice of the manufacturer and the supplier. At this stage, it offers to answer the question whether the products of one, two, or better five suppliers will meet their requirements. At the same time you need to pay attention not only to the characteristics of the equipment, but also to the presence of service centers and warehouses of spare parts and accessories in Russia, to technical support organization. As for the price, the designers experience shows that choice of not the cheapest, but energy-efficient equipment allows to payback costs for its acquisition in a year due to the savings.
«The dividing of the vendors on cheap and expensive is a fairy — tale, agrees Victor Gavrilov, technical director of «AMD Technologies»- each of them has different lines of equipment, technical comparison of which allows you to optimize the cost, fit into the budget and obtain a solution which is the most efficient both in terms of cost and of the operation.«Precisely this approach is used by Victor in selecting the equipment for the design and construction of a direct cooling system of supercomputer with the performance of 10 petaflops for Lomonosov Moscow State University.
From systems of monitoring to...
For the coordinated work of all engineering systems of the data center service operation of this complex object should be able to remotely obtain information on the status and operating parameters of any of their constituent components. As experts admit, monitoring systems have been already introduced in the Russian data centers. And the next step should be their deeper penetration in power distribution cabinets. Why is it necessary? Konstantin Kharitonov, product Manager of Schneider Electric says that it is for remote control of turning machines on/off, energy audit, monitoring energy distribution on the object. Installing of essential bus Acti 9 SmartLink in the power supply can solve these problems. This front-end module of a special type is available in two versions: Modbus RTU and Ethernet. In the first case, it has 11 digital inputs for connecting to instrument and electrical counters and built-in Modbus RS485 connector and a power supply of 24 VDC. The second version of the device differs from the first by seven digital inputs and one analog port and the Ethernet connector RJ45. By using any of the versions operations department gets access to a wide range of useful facilities. These include monitoring of protection of devices, control power of on/off, including remote, moreover recording of total consumption and estimation of the power consumption. All data is stored in the device memory even in case of a power failure. This bus is used for monitoring energy consumption and measuring apparatus in the data centers. The share of projects of implementing Acti 9 SmartLink in data centers at Schneider Electric is about 30%.
The Company Raritan offers means of monitoring of parameters within each server. It has three types of the devices of allocation of electricity supplies: basic measuring PDU, PDU with the function of power management and innovative PDU in its portfolio. The first allows to measure rack temperature, humidity, current, voltage and power factor. The latter can be taken as the basis for the development of long-term strategy to reduce energy consumption in the data center, as they allow implementing several useful scripts at once. For example, to identify the server — a candidate for removal from service or virtualization, or to determine the time intervals during which the productive servers are not loaded, and revise their cooling mode. Innovative distribution devices have USB-port, Wi-Fi and a webcam. Furthermore, ports for sensors are built in them; registration allows to create optimal environment in the racks.
It would seem, that introduction of monitoring tools in the data centers is a direct path to higher level systems, DCIM (Data Center Information Manager), but Alexander Lasyi, deputy Director of the department of intelligent buildings, CROC, called DCIM a very slippery topic in data centers construction, as the suppliers of such systems have not yet been able to convince their customers that they are really important. «In fact — there was no single approach for promoting of such systems for a long time» -agrees Andrey Ivashov, head of the development of Schneider Electric business. In addition, integration of IT and engineering services remained fairly weak, but more recently the interest in such systems was outlined. It is stimulated by the system integrators that serve the vendors allies. Thus, Schneider Electric promotes its solutions in partnership with the integrator unit of HP — HP Converged Management Consulting Services, which offers to apply ITIL methodology of DCIM systems to the implementation.
It should be understood that the needs of customers from different industries are not the same. For example, for providers of colocation services it is important to know the peculiarities of energy consumption of each rack for the formation of quotations to customers and reducing operating costs of an object. Banks, which built fail-operational data centers with the function of monitoring, become to be interested in the security equipment, and the DCIM-system provides the information about the fact which rack which equipment was located with and by what scheme it is reserved (if the scheme is 2N, its operating cost is twofold higher). Resulting in the projected cost of the application, the customer can decide whether to continue using it, or abandon it in favor of cloud services.
In the wake of rising of the demand of such analytics the implementation of DCIM systems will also grow and it will improve the quality of all components of engineering infrastructure and their integrity to a new level, make it simple, logical, and effective from all points of view.