The NTT data center in Frankfurt has one goal:
Energy while cooling
The amount of data worldwide is increasing exponentially. As a result, the market for data centers that process and store this data is also booming. Modern data centers require powerful cooling systems due to the extreme packing density of servers with their high heat loss. Both energy supply and cooling are critical factors for the safe operation of such plants. The EU-wide requirements for greater efficiency are forcing operators to rethink: energy consumption in cooling must be drastically reduced!
NTT’s data center campus, Frankfurt 1 Data Center, is one of the largest locations for data backup, colocation services to complex IT applications and cloud solutions with 60,000 sqm of data center space. The buildings are specially built and equipped for being used as data center. The location is ideal because of the maximum security and availability of infrastructure here. Important aspects were, above all, the secure provision of energy, simple connection to data networks and protection against natural hazards. To meet high customer demand, NTT Global Data Centers EMEA GmbH operates three additional sites in the Frankfurt region alone, which can provide additional space of over 50,000 sqm.
The challenge: Design energy-efficient cooling processes
One of the biggest challenges for NTT, in addition to the continuous and secure power supply, is the enormous waste heat from the servers running around the clock 365 days a year: In addition to the redundant power supply with additional emergency generators or buffer batteries, extremely reliable and equally efficient cooling of the computer cabinets and all other critical areas is therefore necessary. On average, each kilowatt of computing power requires 0.2 to 0.5 kW of cooling power, and the necessary cooling systems are correspondingly large. To make the cooling process as safe and efficient as possible, NTT in Frankfurt relies on a cooling system for the IT equipment with a central chilled water circuit for distribution within the building. Among other things, AC Drives from Danfoss Drives are used. The sophisticated concept covers every area from cooling air flow within the server rooms to the release of thermal energy into the environment.
Safe cooling
AC drives handle pump control. Since the systems were first commissioned in 2003, they have always ensured the optimum flow rate and controlled the motor speed of the pumps using a differential pressure measurement. In this way, they permanently supply the consumers with the required amount of cold water.
The plant has both recooling units, which release waste heat or supply cooling water via the outside air, and chillers that can be switched on if the difference with the outside air is not sufficient during warm periods. The switching on takes place in stages in order to cool as energy-efficiently as possible. In the cold season, the outside air is often sufficient.
In addition to the frequency converters of the VLT series for cold and chilled water pumps, NTT in Continental Europe has been using Danfoss Turbocor exclusively as compressors in the installed chillers for about 2 years, in order to be able to benefit from the stepless speed control of the installed converter here as well. The resulting significant improvement in part-load efficiency is one of several factors that prompted NTT to take this step.
