News in Data Center Cooling Wednesday, 8th May 2013, 16:00h Benjamin Petschke, Director Export - Products Stulz GmbH
News in Data Center Cooling Almost any News in Data Center Cooling is about increase of efficiency : Cooling only when and where it is required, without compromises on reliability and availability.
Different Zones for Cooling
The CRAC Aircooled and Chilled Water
CRAC Cooling Systems Air- and Watercooled
CRAC Cooling System Chilled Water and CW2
Indirect Freecooling System
Direct Freecooling System
Row Cooling Systems
News in Data Center Cooling 1. Implementation of Best Practices 2. Airflow Guidance / Data Center Temperatures 3. Efficient use of Standby CRAC 4. CRAC with fan in the Raised Floor 5. Water as Refrigerant
1. Implementation of Best Practices
TIA 942 Typical datacenter Layout for cabinets/crac Proper Hot and Cold Aisle Configuration with raised floor
TIA 942 Equipment Racks Placement and CRAC units alignment 14
BICSI limitation for Cabinets laying limitation and recommendations 15
Placement of Cables to enhance the airflow 16 Put DATA cables in HOT aisles, up high Put POWER cables in COLD aisles, down low
The Raised Floor 1
The Raised Floor 2
Airflow Leakage 1 Airflow leakages (short air circuit) leads to dramatic inefficiencies due to air circulation back to the CRAC unit without taking heat from the computer equipment. Close all unwanted openings in the raised floor Close all unwanted openings below the racks Close all cable cut outs use cable sealings All gaps (near walls and CRAC units) have to be sealed
Airflow Leakage 2 The target is to create an overpressure under the raised floor to realize an even air supply to all areas of the data-centre. This overpressure can only be achieved with an as low as possible amount of unwanted airflow leakage.
Perforated Tiles Quantity and Opening Factor The number of perforated tiles must be in line with: the design the actual / real airflow Tile number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Example: Design Airflow: 50.000 m³/h, ESP 20Pa Chosen tile: Airflow: 500 m³/h, 20Pa 100 tiles are required Actual Airflow: 30.000 m³/h, Tile number to be reduced to 60
Perforated Tiles: With modulating damper Perforated tiles with integral adjustable dampers can be used to avoid having to replace perforated tiles with solid tiles. In this case the number of perforated tiles can remain unchanged but all tiles need to be adjusted according to the actual requirements in the room. It is also possible to work with different adjustments to vary the amount of air in different areas of the Data Center. In any case the static pressure under the raised floor has to be kept at the design level.
Blanking Panels Recirculation of cooling air inside the rack leads to overheating of servers. Blanking panels installed in unused areas or slots of a rack eliminate a possible internal recirculation of the hot air.
2. Airflow Guidance / Data Center Temperatures
Data Center Temperatures 1 22 C 35 C 13 C 35 C 35 C 13 C 20 C 13 C
Data Center Temperatures 2 35 C 35 C 22 C
Well organised airflow
Data Center Temperatures 3 What does this mean for the cooling equipment design? Less Airflow -> Reduced fan speed and/or smaller CRAC Higher Return Air Temperature -> Smaller CRAC for same capacity Higher Air Temperature Difference -> Smaller CRAC for same capacity Higher Water Temperature -> Smaller Chiller for same capacity
3. Efficient use of Standby CRAC
Standby Management EC Fan Characteristic 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Airflow Absorbed Power 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 1/2 Airflow 1/8 Absorbed Power Airflow Absorbed Power
Standby Management 1 Standby Airflow = 3x 48.000 m³/h = 144.000m³/h Fan power cons. = 3x 9,1 kw = 27,3 kw Lpa,2m = 3x 61,3 db(a) = 66,1 db(a) Capacity: 3x 201,0 kw = 603,0 kw net sensible Airflow = 4x 36.000 m³/h = 144.000m³/h Fan power cons. = 4x 3,9 kw = 15,6 kw Lpa,2m = 4x 54,5 db(a) = 60,5 db(a) Capacity: 4x 163,4 kw = 653,6 kw net sensible Reduction of fan power consumption by 43% Savings: 13.320,-- /year @ 0,13 /kwh
Standby Management 2 Standby Airflow = 3x 48.000 m³/h = 144.000m³/h Fan power cons. = 3x 9,1 kw = 27,3 kw Lpa,2m = 3x 61,3 db(a) = 66,1 db(a) Capacity: 3x 201,0 kw = 603,0 kw net sensible Airflow = 4x 32.700 m³/h = 130.800m³/h Fan power cons. = 4x 3,0 kw = 12,0 kw Lpa,2m = 4x 52,2 db(a) = 58,2 db(a) Capacity: 4x 151,3 kw = 605,2 kw net sensible Reduction of fan power consumption by 56% Savings: 17.420,-- /year @ 0,13 /kwh
4. CRAC with fan in the Raised Floor
CRAC with fan in the Raised Floor
CRAC with fan in the Raised Floor
CRAC with fan in the Raised Floor Fan power consumption 1 12,0 Fan power [kw] 10,0 8,0 6,0 4,0 2,0 2 0,0 18.000 22.000 26.000 30.000 34.000 38.000 42.000 46.000 50.000 54.000 Air flow [m³/h] CRAC with fan above the raised floor CRAC with fan in the raised floor 1 25% higher airflow ESP = 20Pa 2 Reduction of the fan power consumption by 47%
5. Water as Refrigerant
Water as Refrigerant New technology for data centers Designed for a no-cost, environmentally friendly refrigerant Provides the very hightest efficiency and sustainability Moving from technical to economical feasibility
Water as Refrigerant Standard water from water supply system No water treatment required Water hardness not a problem Fully environmentally compatible Infinitely available refrigerant - free of charge
Water as Refrigerant No toxicity or flammability No production energy required ODP = 0 No LGWP, but ZeroGWP GWP = 0 TEWI never reached before
Environmental Sustainability ODP Ozone Depletion Potential Relative indicator for the ozone depletion related to the ODP value 1 of the substance Trichlorfluoromethane (R11) GWP Global Warming Potential Relative measure of how much heat a greenhouse gas traps in the atmosphere comparing the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide as reference value (CO 2 =1) Commonly calculated over a period of 100 years, f. e. methane GWP = 25, R 134a = 1430 = 0 = 0
Environmental Sustainability Leackage rate (kg/a) Operating period(a) Filling quantity(kg) Recovery rate (kg) CO2 emmision per Energy unit (kg/kwh) TEWI Total Equivalent Warming Impact TEWI = GWP x L x n + GWP x m x (1 α R ) + n x Ea x β Annual energy Consumption (kwh/a) = World s Lowest TEWI: Calculation method to evaluate the influence of cooling systems on the greenhouse effect
high Sustainability CRAC with water as refrigerant low Economy (TCO, ROI) low Ecologic Compatibility high
Thermodynamics Water is an environmentally-friendly substance, however water offers difficult thermodynamic attributes that need to be overcome. Water characteristics require a special cooling circuit and compression process. Water (R718) R410a Vapour pressure 0,017 bar 0.246 psi 12,5 bar 181 psi Vapour density 0,0128 kg/m³ 0.0008 lb/ft³ 48 kg/m³ 3 lb/ft³ Volumetric refrigerant capacity 30,8 kj/m³ 0.828 Btu/ft³ 7355 kj/m³ 197 Btu/ft³ Pressure ratio for temperature lift 32K Volume flow for 45 kw (154 Btu/h) capacity Mass flow for 45 kw (154 Btu/h) capacity 6,6 6.6 2,3 2.3 5.250 m³/h 3,090 cfm 22 m³/h 12.95 cfm 67 kg/h 2.47 lb/min 1056 kg/h 38.8 lb/min
CRAH Air Section System Design Drycooler Primary side pump echiller Water Piping Secondary side pump CRAH Underfloor Fan Section
Thermodynamics Warm water Cold water Heat Removal OUT Heat Removal IN
Thermodynamics An entirely new evaporating, compressing and condensing process has been developed
Operating Principle - 1
Operating Principle - 2
Operating Principle - 3
Operating Principle - 4
The Turbine Unique three dimensional structure Specially developed, composed granulate material Absolutely oil free operation of all components Extremely high turbo compressor efficiency
The EC Motor Highest EC motor efficiency Efficiency > 98% (w/o inverter) and 95% with inverter Quasi loss-free magnetic bearing (axial and radial) Lubrication free bearing Unmatched emergency operation capability, passively stable Tested up to 100.000 rpm Friction and wear free Vibration free, super low noise operation
Free Cooling Build-in Indirect Free Cooling Free cooling operations starts a few degrees below desired supply air temperature No additional free cooling heat exchanger required; very low internal pressure loss, thus increased efficiency and lower sound pressure Precise temperature control with step-less high efficiency pump; No control valves, thus low hydraulic pressure drop Step-less adjusting condensing temperature without the high condensing pressures of conventional systems
Free Cooling Stages Ambient Temperature 102-77 F 39-25 C 76-64 F 24 C-18 C 63-54 F 17 C-12 C <53 F <11 C Mode DX Stage 2 DX Stage 1a DX Stage 1b Free Cooling CRAH Fan Fixed Speed or Raised Floor Pressure Controlled CRAH Pump Speed Controlled on Air Temperature Setpoint echiller Turbines 3x proportional 2x proportional 2x proportional Off echiller Pumps 3x maximum 3x medium 3x minimum 2x minimum / 1x proportional Drycooler Pump maximum speed proportional Drycooler Fan maximum speed proportional
Highest System EER 14 12 CRAC with water as refrigerant Aircooled CRAC EER 10 8 6 EER = Absorbed Power (all system components) Cooling Capacity 4 2 0 0 4 8 12 16 20 24 28 32 36 Ambient Temperature [ C]
70 60 Excellent COP CRAC with water as refrigerant Aircooled CRAC 50 COP 40 30 COP = Absorbed Power (Compressor / echiller) Cooling Capacity 20 10 0 0 4 8 12 16 20 24 28 32 36 Ambient Temperature [ C]
100 Part Load Efficiency Relative Power Consumption 80 60 40 20 0 35 C Ambient Temperature 20 C Ambient Temperature 10 C Ambient Temperature Linear 20% 40% 60% 80% 100% Heatload
ROI TCO [k ] 120 100 80 60 40 20 0 CRAC with water as refrigerant Aircooled CRAC ROI ~ 3 Years 1 2 3 4 5 6 7 Year @ 0,13/kWh
Regulations CRAC with water as refrigerant anticipates new upcoming regulations Avoids tax regulations Examples for 134a: Denmark 17.5/Kg, Norway 39/Kg Taxation coming up in Sweden and Australia CRAC with water as refrigerant avoids room safety regulations for installation and service
Water as refrigerant - Summary Water as refrigerant Innovative, reliable and secure system Highest efficiency and sustainability Competitive energy savings Build-in indirect free cooling Anticipates new upcoming regulations
Many thanks for your attention.