Embed Size (px)
Citation preview
Adiabatisch koelsysteem voor CO2-koelsystemenHans Reinders
Save up to 30% on the running costs of your
cooling system11/23/2017 Confidential
PreCooll®
Content
11/23/2017 Confidential 4
• Background: Transcritical and Subcritical Processes
• Pre-cooling on a CO2 gas cooler
• Oxycom’s PreCooll®
• Key Components & Key Features
• Adiabatic Cooling Principle
• Examples of Realized Project & Potential Savings
• Transcritical operation
• CO2 above 31 °C and 73 bar
Whenever air entering the condenser has a temperature above 20-23 °C
• Low cooling capacity
• High energy consumption
• Low EER (COPc)
11/23/2017 Confidential 5
Transcritical Process
• Subcritical operation
• High cooling capacity
• Low energy consumption
• High EER (COPc)
11/23/2017 Confidential 6
Subcritical Process
Content
11/23/2017 Confidential 7
• Background: Transcritical and Subcritical Processes
• Pre-cooling on a CO2 gas cooler
• Oxycom’s PreCooll®
• Key Components & Key Features
• Adiabatic Cooling Principle
• Examples of Realized Project & Potential Savings
Pre-cooling on a CO2 gas cooler
• Subcritical processes are more
efficient
• Installing a PreCooll® unit before
the condenser allows to switch
from a transcritical process to a
subcritical one
• CO2 below 31 °C and 73 bar
11/23/2017 Confidential 8
Source: Emerson Climate
Conversation
11/23/2017 Confidential 9
Pre-cooling on a CO2 gas cooler
• Pre-cooling always
increases the EER
• The advantage is
significantly higher in
subcritical operation
• 3.8% per °C transcritical
• 6.7% per °C subcritical
11/23/2017 Confidential 10
Pre-cooling on a CO2 gas cooler
• Pre-cooling always
increases the cooling
capacity
• The advantage is
significantly higher in
subcritical operation
• 1.1% per °C transcritical
• 1.7% per °C subcritical
Content
11/23/2017 Confidential 11
• Background: Transcritical and Subcritical Processes
• Pre-cooling on a CO2 gas cooler
• Oxycom’s PreCooll®
• Key Components & Key Features
• Adiabatic Cooling Principle
• Examples of Realized Project & Potential Savings
11/23/2017 Confidential 12
Oxycom’s PreCooll®
• Energy savings of
up to 30%
• Lower compressor
peak loads
• Increased chiller
lifetime
• Lower fan speed,
lower noise level
11/23/2017 Confidential 13
Oxycom’s PreCooll®
Retrofit to existing condenser section:
11/23/2017 Confidential 14
Oxycom’s PreCooll® - NEN 5060 2008
Content
11/23/2017 Confidential 15
• Background: Transcritical and Subcritical Processes
• Pre-cooling on a CO2 gas cooler
• Oxycom’s PreCooll®
• Key Components & Key Features
• Adiabatic Cooling Principle
• Examples of Realized Project & Potential Savings
11/23/2017 Confidential 16
Key Components
• Aluminum with corrosion-resistive coating
• Unique shape breaks up airflow and
minimizes boundary layer formation
• Superior heat transfer coefficient
compared to plate heat exchangers
(typically 200 W/m2K vs. 40 W/m2K)
• Hydrophilic and hygroscopic coating on
both sides of the fin
Unique highly efficient fin material
11/23/2017 Confidential 17
Key Features
• Superior cooling performance
• Low pressure drop
• Fully modular concept
• Integrated water distribution system
• Self-cleaning design
• Allows use of regular tap water
• VDI 6022 hygiene certified
Cooling
performance:• 89−93% saturation efficiency
• Independently confirmed by TNO in The Netherlands and
CSIRO in Australia
11/23/2017 Confidential 18
Key FeaturesOXYVAP Paper pad
Thickness 90 mm 190 mm
Saturation efficiency* 89% 89%
Pressure drop* 45 Pa 68 Pa
Carrier material Aluminum Paper
Self-cleaning fins Yes No
Sensible to fungus & algae No Yes
Droplet eliminator required <3.0 m/s
No Yes
*Performance data for 2.0 m/s air velocity.
11/23/2017 Confidential 19
PreCooll® Design
Modular design: Ease of Installation and
Maintenance
Content
11/23/2017 Confidential 20
• Background: Transcritical and Subcritical Processes
• Pre-cooling on a CO2 gas cooler
• Oxycom’s PreCooll®
• Key Components and Key Features
• Adiabatic Cooling Principle
• Examples of Realized Project & Potential Savings
11/23/2017 Confidential 21
Adiabatic Cooling Principle
• Aluminum with corrosion-resistive coating
• Conversion of sensible energy
(temperature) into latent energy (humidity)
• Powered by water, one of nature’s most
powerful refrigerants (R718): 1 L/h of
evaporation, almost 700 W of cooling).
• Both air and water outlet are cooled down
close to the wet bulb temperature
Content
11/23/2017 Confidential 22
• Background: Transcritical and Subcritical Processes
• Pre-cooling on a CO2 gas cooler
• Oxycom’s PreCooll®
• Key Components and Key Features
• Adiabatic Cooling Principle
• Examples of Realized Project & Potential Savings
11/23/2017 Confidential 23
Oxycom’s PreCooll® Installations
Befor
e
After
Supermarket Raalte – The
Netherlands
11/23/2017 Confidential 24
Oxycom’s PreCooll® Installations
Supermarket Purmerend – The
Netherlands
Photo published with the kind permission of Retail Technics – Nijkerk, The
Netherlands
11/23/2017 Confidential 25
Example of Realized ProjectExample (Trane RTAC 500J):
• Increase of COP: 2.79% per °C pre-cooling.
• Increase of cooling capacity: 1.33% per °C pre-cooling.
Outdoor air temperature
[°C]
Cooling capacity[kW (ton)]
Power consumption
[kW]
COP[kW/kW
(BTU/W∙h)]
30 1821 (518) 527 3.46 (11.8)
35 1716 (488) 564 3.04 (10.4)
40 1607 (457) 606 2.65 (9.0)
45 1494 (425) 653 2.29 (7.8)
11/23/2017 Confidential 26
NEN 5060 2008
Impact (at 30 °C DB / 23.7 °C WB outdoor air*):
• Condenser inlet temperature after pre-cooling:
24.4 °C.
• New COP: 3.56 x 1.0279(30–24.4) = 4.15 (+17%).
• Energy savings: 1 – 3.56/4.15 = 14%.
*Source: ASHRAE Standards
Potential Savings – NEN 5060 2008
Yearly Energy Savings:
15 - 20%
Oxycom Fresh Air B.V.Kaagstraat 31 – NL-8102 GZ Raalte – P.O. Box 212 NL-8100 AE Raalte
T: +31(0572) 349 400 E: [email protected] I: www.oxy-com.com
THANK YOU
11/23/2017 Confidential 27
