Sea Water Cooled Chillers
Amar Farjo
Senior Staff Engineer
Industrial Systems, Building Efficiency
Why do we need to consider sea
water cooled chillers?
Because they can save 57,600
Gallons (218,016 Liters) of
potable water per 1,000 Tons
of cooling everyday
Agenda
- Sea water cooled chiller products by YORK
- Chiller Operation
- Sea Water Quality Specification
- Material Options
- YORK Reliability
3
YORK Products with Sea Water Capability
YDYKSingle Compressor
Dual
Compressors
YB & YGGas- engine
Drive
CYKCompound
Compressors
YIASingle Stage
Titan OMYPCTwo Stage
4
Customer
Designed
YSTSteam Turbine
Agenda
- Sea water cooled chiller products by YORK
- Chiller Operation
- Sea Water Quality Specification
- Material Options
- YORK Reliability
5
Centrifugal Chiller
Prerotation Vanes
Impeller
Mist Eliminator
Diffuser Plate
Condenser
Flooded
Evaporator
Subcooler
6
Orifice
Pressure – Enthalpy Diagram
Pressure
Condenser
Lift
(or Head
Pressure)
Metering
Device
Evaporator
Enthalpy
7
Refrigerant rejects
heat to atmosphere
Compressor
Refrigerant absorbs
heat from load
Pressure – Enthalpy Diagram
Pressure
90° F 32° C
100° F 38° C
Lift
(or Head
Pressure)
54° F 12° C
44° F 7° C
Enthalpy
8
Agenda
- Sea water cooled chiller products by YORK
- Chiller Operation
- Sea Water Quality Specification
- Material Options.
- YORK Reliability
9
Water Quality Specification for Filtered Brackish or Seawater:
pH
Total Suspended Solids, ppm
Make-up
Water 4
Concentrated Cooling Tower
Water 2,5
pH
6.5 - 8.8
< 9.0
Total Dissolved Solids, ppm
< 50,000
[Dissolved Solids] must be below the solubility limits
200 - 350
450 - 650
< 0.02
< 0.01
< 525
< 975
< 2.0
< 0.1
[Cl] must be below the solubility limit for the chemical
treatment program
[SO4] must be below the solubility limit for the chemical
treatment program
< 150
Parameter
6.5 - 8.8
< 2.0
Total Alkalinity, ppm as CaCO
Total
Suspended
Total Hardness (Ca + Mg), ppm as CaCO
Iron, ppm as
Fe
Solids,
ppm
Copper, ppm as Cu
< 2.0
Chloride, ppm as Cl
1000 - 28,000
Sulfate, ppm as SO4
1000 - 4,000
Silica, ppm as SiO2
< 100 at 1.5 cycles
3
3
Phosphonate, ppm as P2O5
1000
< 0.5 28,000
< 0.5
Chlorine, free, ppm as Cl
TOC (mg/L)
Ammonia, ppm as NH3
Sulfides, ppm as SO2
Aerobic Bacteria, CFU/ml
Anaerobic Bacteria, CFU/ml
Coliform, (counts per 100/ml)
E-Coli, (counts per 100/ml)
BOD (mg/L)
COD (mg/L)
0.1 - 0.5
<2
06
0
2
< 1x10
6
0
0
0
0
0
Chloride, ppm as Cl
Phosphate, ppm as PO4
Ammonia, ppm as NH3
0
< 9.0
< 10
< 10
[Cl] must be below the
solubility
limit
the
Phosphate-based
corrosion
inhibitors for
are seldom
added.
Phosphonate-based
corrosion
inhibitors are seldom
chemical
treatment
added.
0.2 - 1.0
program
2
Requires good feed control of oxidizing biocide
<1 3
0
< 1x103 3
0
0
0
0
0
2 Chlorine, free [Clfree] = 2.0 ppm may be required in systems with high nutrient loading and/or drift.
3 Limit applies to CuNi tubes only. No limit for titanium.
4 Make up water concentration levels may change based on number of cycles.
5 Water that will be utilized for condenser heat exchanger.
6 Make-up water with even trace amounts of ammonia is considered to be polluted.
<1
3 Limit applies to CuNi tubes only. No limit for titanium.
10
Agenda
- Sea water cooled chiller products by YORK
- Chiller Operation
- Sea Water Quality Specification
- Material Options
- YORK Reliability
11
Recommendations protection
against:
- Corrosion
- Erosion
- Deposition
Heat Exchanger Tube Options
Options
Material
Wall
Thickness
Baseline 1
Copper
0.025
Baseline
Baseline
Base
line
Baseline
#1
70/30
CuNi
0.028
↑
↓
↑
↑
#2
Titanium
0.028
↑↑
↓↓
↑
↑↑
1 Copper
Life
Pressure Kw/
Chiller
Maintenance
Expectancy
Drop
ton First Cost
tubes are shown in the table above for baseline comparison purposes only. Copper tubes are not suitable for sea water applications.
Copper Nickel (CuNi)
- 70% Cu/30% Ni offers reliable operation, acceptable if, water is
consistent in quality, Maintenance is performed routinely .
-90% Cu/10% has been used but there is increased risk due to the
reduced corrosion resistance
Titanium
- Gold standard, immune to erosion & corrosion
- Upgrade in tube material
- Longest life expectancy
- Highest cost option
12
Baseline
Chiller Efficiency
4.95
Efficiency
Copper
4.9
4.85
COP
4.8
4.75
4.7
CU/NI 70/30
Titanium
4.65
4.6
13
Tube Material
Chiller Cost
2.25
Cost
2.00
Titanium
Cost
1.75
1.50
CU/NI 70/30
1.25
1.00
Copper
0.75
14
Tube Material
Tubesheet Options
Carbon Steel with Ceramic Coating
-Will ensure reliable operation and protection against
corrosion/erosion.
-But maintenance and annodes are required
Carbon Steel with Cladding
- Best option for tubesheet protection
- Higher costs but expected service life is higher
- Cladding material for the tubesheet must be the same
as the tubes
15
Explosion Titanium or CUNI Clad Tubesheets Manufacturing
Explosive
powder
Space between
Plates
1. Plane material
inspection
2. Grind Mating
services
3. Assembly:
Backer, Cladder, Explosive
Metallurgical
Weld Line
4. Explosion
Collision Point
Mechanical Test
Specimens
5.Flattening
and cutting
6.Testing & Inspection
7. Cut Parts for shipment
Ultrasonic Examination of bond, Mechanical Test
Physical Measurement, Certification
removes Any Edge Defects.
Cutting by Torch, Waterjet, or Saw
Source: DMC, Dynamic Materials Corporation
16
Edge Trim- Scrap
Waterbox Recommendation
Carbon Steel with Ceramic Coating
- Ceramic Coating (Polymer Composite)
- Ensure reliable operation
- Protect against corrosion/erosion
- Anodes should be provided and maintained if coatings is
requested to protect against corrosion if coating holidays*
occur
*Holidays- discontinuity or break in a coating, exposing the base bare metal
underneath
17
Additional Recommendations
Couplings/ Plugs, Thermowells, Flow Switches
-Monel will ensure reliable operation
Unit Accessories
- Evaporator water should be used as cooling water for VSD or SSS and
used with water cooled oil coolers for sea water applications , Motors ???
Anodes
(serve as an electrode, electric current flows into
a polarized electrical device capturing charged
materials in water ; reducing corrosion)
- Correct anode material will protect against
corrosion if coating holiday occurs
18
Agenda
- Sea water cooled chiller products by YORK
- Chiller Operation
- Sea Water Quality Specification
- Material Recommendations
- YORK Reliability
19
YORK Sea Water Chiller Installations
Proven Reliability
United States Navy
Surface and
Subsurface Vessels
Bahrain Bay
20
Hong Kong Bay
Questions
21