Upload
phamthu
View
225
Download
14
Embed Size (px)
Citation preview
Data Center Design GuidefeaturingWater-Side Economizer Solutionswith Dynamic Economizer Cooling
Presenter:Jason Koo, P.EngSr. Field Applications EngineerSTULZ Air Technology Systems
jkoo@stulz‐ats.com
Water‐Side Economizer Solutions
OutlineASHRAE Standards and Guidelines relative to Precision Cooling
– ASHRAE 127‐2012– CEC Requirements– ASHRAE TC 9.9 – 2011– ASHRAE 90.1 ‐ 2010
Air & Water‐Side Economizers
ASHRAE 127‐2012
New Test Standards• ASHRAE 127‐2012 Method for Testing for Rating Computer and Data
Processing Room Unitary Air Conditioners defines performance teststandards
• The purpose is to establish a uniform set of requirements for ratingprecision cooling equipment
• Significant changes in the 2012 edition1. Higher return air temperatures, thus increasing efficiency
• 75, 85, 95, 105 degrees F DB2. Higher chilled‐water entering temperatures3. A testing/rating procedure for equipment4. A testing/rating procedure for the newer technologies
a. Row based cooling systemsb. Containment systems
Raising return air temperature using containment• With a raised floor (Figure 1)
– Raised floor is pressurized with cold air from the precision cooling units
– Cold air passes through perforated floor tiles, taken into the servers, heated and exhausted into the contained hot aisle
– Hot air is directed back to the ceiling plenum, then returned to the CRAH units
• With a slab floor (Figure 2)– Utilizes server racks that have a top
ducted chimney connection– A CRAH with front discharge floods
the space with cold air, allowing the servers to take cold air in from the front
– Hot air is discharged out to the chimney and returned to the CRAH unit via a return duct or ceiling plenum
Update of CEC Requirements
On July 1st 2014• Adopting the SCOP requirements of ASHRAE 90.1‐2010 which are based
on the ASHRAE 127‐2007 test standard (75°F and 52° DP EAT’s)
• Requires 100% testing of a representative of each unit that will be offeredfor sale in the state of California
• Elimination of non‐adiabatic humidification and reheat
Adiabatic cooling provided (BTU/h)
Total KW/H per year*
Cost Per KWH
Annual Cost of
Electricity
Ultrasonic 2,095,200 799,973 x $0.11 $87,997
Feature Infrared Humidifier STULZ UltrasonicTechnology Infrared Ultrasonics
Capacity (lbs./hr.) 22 18
Energy Consumption (Watts) 9,600 585
Water Requirements Non‐conditioned city water
Demineralized water using RO and DI
Maintenance Requirements ½ hour to remove mineral buildup in pan
No cleaning of ultrasonic required
Humidification Improves Efficiency
*KWH based on 1.23 KW/Ton for air cooled chiller
HumidificationTechnology
Number of Humidifiers Required
Watts Consumed
Annual Hours Of Operation
KW/H per year Cost Per KWH
Annual Cost of
Electricity
Annual Savings
Infrared 98 x 9,600 x 3,725 x 3,504,480 x $0.11 x $385,493
Ultrasonic 120 x 585 x 3,725 x 261,495 x $0.11 x $28,764 $356,728
Humidification Energy Comparison
Free Cooling Energy SavingsHumidification
and Free Cooling Energy
Savings$444,725
Combined
STULZ Ultrasonic Humidifier
DRH –Direct Room Humidifier
• Mounts below the ceiling in a conditioned space• On wall or column with factory furnished mounts• Suspended from above in open space • Integral blower and washable filter • Absorption distance determined by RH of room
Ultrasonic Humidifier in Space
STULZ Ultrasonic Humidifier
DAH –Ducted Air Humidifier
• Mounts in moving air stream of AHU or ductwork• Multiple humidifiers assembled on factory rack system• Air velocity design similar to heating/cooling coils • Factory accessories for optimized airflow and mist control• Absorption distance determined by RH of airstream
Ultrasonic Humidifier in Duct
ASHRAE Standards and GuidelinesASHRAE TC9.9 2011• Allowance for increased delta‐
T across server equipment• Offers an opportunity to raise
the return air temperatures to the cooling equipment
• Current trend for maximum efficiency in the data center – isolate the hot return air
from the cold supply – prevent air mixing
• Opportunity to raise the delta‐T between the supply air temperature from the cooling equipment to the IT equipment and the return air temperature from the IT equipment to the cooling equipment
What Has Changed Inlet Air Temperature
Moisture Content
2004 Recommended (old)
68‐77.0°F DB 40% RH to 55% RH
2011 Recommended (new)
64‐80.6°F DB 41.9°F DP to 60% RH & 59°F DP
2011 Allowable (A1) 59‐89.6°F DB 20‐80% RH up to 62.1°F DP
Coil Calculations and Optimization• Higher return air
temperature to the CRAC/CRAH equipment increases cooling efficiencies
• Increase Entering Air (to CRAH)
– Improve Net Sensible Capacity
– Decrease CRAH Unit Power– Decrease Chiller Power– Mix and match to achieve
optimal conditions– More economizer hours,
lower PUE, and lower energy costs
ASHRAE 90.1 – 2010• Since data centers have been
identified to consume ~3% of the total energy produced in the U.S., the former process cooling exemption is gone.
• Water‐side economizers must meet 100% of the expected load with cooling towers when operating at or above 40°F dry bulb / 35°F wet bulb and with dry coolers when operating at or below 35°F dry bulb.
• Evolution of Measuring Efficiency– ASHRAE 127 – 2007 guideline for
Sensible Coefficient of Performance (SCOP)
– ASHRAE 90.1 – 2010 guideline for SCOP (used for this presentation)
– ASHRAE 127 – 2012 guideline for Net Sensible Coefficient of Performance (NSenCOP)
The DOE is mandating that all states adopt ASHRAE 90.1‐2010, or a more stringent standard, for new data center design and construction by October 2013.
Direct Free Cooling System, butcustomer provides dampersystem and filtration, andcontrols its operation.
Air Side Economizers
Outside Air & Moisture OperationWarmer / High Humidity Dampers close & the CRAC/CRAH revert to traditional operation
Within Proper Range Outside air is directly introduced through the dampers in the mixing box
Colder than Desired Dampers mix outside air & return air to achieve desired temperature
Air Side Economizers
Vertical and horizontal mixing boxes for air-side economizer options using floor-standing CRAC’s or CRAH’s
• CRACs or CRAHs with an integrated mixing box and damper controls provide direct free cooling
• Units attached to the top of a CRAC or CRAH in a vertical or horizontal position
• Pre-filter and freeze protection damper options
• Mixes outside and return air depending on outside air conditions
• Full economizer controls provided by the CRAC or CRAH
Air‐Side Economzer
Vertical & Horizontal Mixing Boxes
Air‐Side Economzer
Direct Air-Side Economizer • Outside air (less than supply air
temp) is directly introduced into the data center
Direct Adiabatic Cooling• The outside air is cooled with an
adiabatic system and directly introduced into the data center
Direct DX Cooling• The outside and/or return air is
cooled with a DX evaporator coil and directly introduced into the data center
Air‐Side Economizer
CyberHandler (AHU) with Direct Air Economizer, Direct Adiabatic Cooling, and DX for trim
Direct Air-Side Economizer • Outside air (less than supply air
temp) is directly introduced into the data center
Direct Adiabatic Cooling• The outside air is cooled with an
adiabatic system and directly introduced into the data center
Direct DX Cooling• The outside and/or return air is
cooled with a DX evaporator coil and directly introduced into the data center
Air‐Side Economizer
CyberCon (Modular/Container) with Direct Air Economizer, Direct Adiabatic Cooling, and DX for trim
DX Cooling Section with Humidification
Ex. Nortec V‐Profile Evaporative Pad
• An option is to add an adiabatic pad for direct adiabatic cooling before the DX Coil
• DX Coil used for trim capacity
• Ultrasonic Humidifier used for humidification
DX CoilUltrasonicHumidifier
Air‐Side Economizer
Indirect Air-Side Economizer• Outside Air (less than supply air temp) passes through an air-to-air heat exchanger
to indirectly cool the data center return air
Indirect Adiabatic Cooling• The return air is indirectly cooled via an air-to-air heat exchanger that has an
adiabatic spray applied to it
Air‐Side Economizer
CyberHandler with Indirect Air Economizer, Indirect Adiabatic Cooling, and DX for trim Indirect Adiabatic
Cooling Module
DX CRAC with Economizer Coil and Condenser Loop• Used with the following Water‐Side
Economizers:– Traditional Economizer Cooling– Variable Economizer Cooling– Evaporative Tower Economizer
Cooling
Types of Water Side Economizers
• DX Economizer Solutions– Traditional Economizer– Variable Economizer– Evaporative Tower Economizer
• CW Economizer Solutions– Dual‐Source Chilled Water
Economizer– Dynamic Economizer Cooling
• Standard• Optimized
Traditional Economizer Cooling Comparison• Traditional Economizer
Cooling– Constant fan speed dry
cooler • fans cycled on and off based
on fluid temperature
– Constant speed pumps– Water/glycol cooled free
cooling CRACs • DX cooling coil and
water/glycol free cooling coil
• Comparison of a CRAC to a CRAC with Free Cooling Coupled with a Constant Speed Fan Dry Cooler– Baltimore, MD– Salt Lake City, UT (4,500 ft
altitude)– Portland, OR
Variable Economizer Cooling Comparison• Variable Economizer Cooling
– Variable fan speed dry cooler
• fan speed controlled based on fluid temperature
– Variable speed pumps • controlled based on fluid
temperature– Water/glycol cooled free
cooling CRACs• DX and water/glycol free
cooling coil
• Comparison of a CRAC to a CRAC with Free Cooling Coupled with a Variable Speed Fan Dry Cooler– Baltimore, MD– Salt Lake City, UT (4,500 ft
altitude)– Portland, OR
Evaporative Tower Economizer Cooling Comparison• Evaporative Tower
Economizer Cooling– Closed loop evaporative
cooling tower • Controlled based on fluid
temperature
– Constant speed pump– Water/glycol cooled free
cooling CRACs• DX and water/glycol free
cooling coil
• Comparison of a CRAC to a CRAC with Free Cooling Coupled with an evaporative cooling tower– Baltimore, MD– Salt Lake City, UT (4,500 ft
altitude)– Portland, OR
Comparison of DX Economizer Cooling% Reduced Energy• Baltimore MD
– Traditional Economizer Cooling verses DX Cooling ‐13%
– Variable Economizer Cooling verses DX Cooling ‐31%
– Evaporative Cooling Tower Economizer Cooling verses DX Cooling ‐32%
Dual‐Source Chilled Water Economizer Cooling• Dual‐Source Chilled Water
Economizer Cooling– Evaporative cooling tower and
pump• controlled based on fluid
temperature– Air‐Cooled Chiller and pump
• controlled based on fluid temperature
– CRAH units• dual circuited interlaced chilled
water cooling coil
• Comparison of a CRAH Coupled with an Air‐Cooled Chiller to a CRAH with Dual Coils Coupled to an Air‐Cooled Chiller and Evaporative Cooling Tower– Baltimore, MD– Salt Lake City, UT (4,500 ft
altitude)– Portland, OR
Dynamic Economizer Cooling (DEC)• A Dynamic Economizer Cooling
(DEC) system (state‐of‐the‐art water‐side economizer solution)– Evaporative cooling tower– Air‐ cooled chiller– Cooling tower and chiller pumps– Control mixing valves– CRAH units
• Required cooling fluid temp < ambient conditions = operates in the cooling tower mode
• Required cooling fluid temp > ambient conditions = operates in the “chiller assisted cooling©” mode
• System minimizes hours of chiller operation and optimizes opportunity for economization
Warm Water Cooling
Power Usage Effectiveness (PUE)Evaluating Power Usage Effectiveness• Power Usage Effectiveness (PUE)
– Measurement of data center efficiency (by The Green Grid)
• PUE = (IT Load + Total Power) / IT Load– IT Load is the effective processing equipment power of the data center– Total Power includes security, cooling, lighting, fire monitoring, etc.
• Industry Benchmarks– PUE < 1.6 considered very good– PUE < 1.2 is state‐of‐the‐art
Latest News
Outdoor Cooling Indoor Cooling Retrofit and Conditioning
Utility Rebates Further Improve ROI
Utility Rebates Further Improve ROI
• Many utility companies are running out of capacity
• Most utility companies are offering incentive programs for:
• Retrofitting existing cooling equipment
• Replacing cooling equipment
• Installing new energy efficient cooling equipment
• Most energy efficient solutions available
• Sales Rep and Applications Engineering can:
• Help calculate the energy savings for STULZ solutions
• Provide you with an energy analysis report
• Sales Rep can:
• Introduce you to your local utility
• Initiate the rebate process by starting the paperwork
Customers have received hundreds of thousands of
$’s in rebates
Conclusions
• By providing an economizer, power usage is significantly reduced during cooling ambient conditions.
• By elevating return air temperature and elevating water temperatures, effective economizer hours are increased.
• Increase in effective economizer hours will reduce energy consumption of the cooling equipment.
• Reduction of energy by cooling equipment equates to smaller PUE values.
• Additional Savings Potential (Energy and Capital)– Eliminate the raised floor by utilizing CRAH’s with front discharge and
racks with integrated hot air containment (entire white space used as a cold aisle)
– Reduce chiller requirements and related maintenance, by specifying/sizing only for the minimum trim capacity required
– Reduce gen‐set requirements and related maintenance, by specifying/sizing for the much lower energy required by the system
Presenter:Jason Koo, P.EngSr. Field Applications EngineerSTULZ Air Technology Systems
jkoo@stulz‐ats.com