uk naval ships hvacr maintenance of legacy systemsashrae.gr/eeins2015/eeins2015_steward.pdf ·...
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UK Naval Ships HVACR – Maintenance of Legacy Systems
Robin Steward [email protected]
Younus Abbas [email protected]
Babcock International Group Energy and Marine Technology
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Objectives
• Operation and maintenance of HVAC
• Standards and legislative framework
• Issue 1. Ventilation fresh air improvements for health of crew
• Issue 2. Upgrading air conditioning on UK Naval Ships: Option 1. Upgrade to whole system
Option 2. Reducing the chilled water supply temperature
Option 3. Efficiency savings using air-to-air recovery
Scope: Ventilation and chilled water system on naval vessels
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Outline
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
– Overview of ship and HVAC – Part1: Fresh air upgrade to ventilation system
• Ventilation overview • Flow rate assessment • Proposed solutions • Summary
– Part2: Air Conditioning Upgrade • Current System Overview • Using standard CW temperatures • Using lower CW temperatures • Using energy recovery units • Summary
– Questions
Ship & HVAC Overview
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Ship particulars
• Personnel distribution: 342 crew, 1052 full compliment
• Design conditions: Tropical summer (31 °C DB) to sub-arctic winter (-10 °C DB)
• Chilled water plants capacity: 2.8 MW
• Fresh air supply: 12 m3/s
• Recirculated Air: ~80%
• Exhaust: 3m3/s
Part1: Fresh Air Assessment and Upgrade
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Fresh Air Safety Requirements
Legislation - Fresh air 5 – 8 L/s per person
- Oxygen >19.5%, nominally 21%
- Carbon dioxide < 0.5%, nominally 0.03%
Standards - 15 air changes per hour
- CO2 below permitted maximum levels
- At whole ship 13 L/s per person
Constraints:
• Accuracy of Measurements and Balancing
• Changing distribution of personnel
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Ventilation System Overview
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
F.A.
AFU
AHU
HEATER
FILTERED AIR
BATHROOM
AND HEADS
GENERAL
COMPARTMENT
RECIRCULATION FILTER
HEATER
AHU
EF
Fresh Air Make-Up Assessment
Whole Ship:
Personnel requirements (1052) - 13.7 m3/s
Ship supply - 12 m3/s
Example zone:
Zone personnel requirement (331) - 4.3 m3/s
Zone supply - 3.0 m3/s
Example AHU:
AHU personnel requirement (94) - 0.8 m3/s
AHU supply (calculated) - 0.6 m3/s
AHU supply (measured) - 0.5 m3/s
Whole ship exhaust - 3 m3/s
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Ventilation Solutions
1.Monitor air quality
2.Upgrade fresh air and exhaust • Example ship +2 m3/s
3.System management • Air flow diagrams
• Software analysis
4.Automation Upgrade • AHU to AFU flow control
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Fresh Air and Ventilation Summary
1. Discrepancies between safety guidance and calculated fresh air make-up
2. Key solutions:
• Increase air flow through ship
•Automation of flow between AFU and AHU
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Part2: Upgrading Air Conditioning System
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Existing HVAC System
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
M
Evaporator
Condenser Compressor
CW
PUMP
Cooling
Coil Fan
Air
Handling
Unit (AHU)
Thermostat
Exhaust
Solar Radiation
Supply
Air
Recirculated
Air
Fresh Air
from AFU
Re-
Heater
Pre-Heater
Hot Machinery Spaces
Sea Water
S
W
O
CW Plant
E
O
M
W
ADP S
E
31°C db, 27°C wb
29.5°C db, 22.0°C wb
7.5°C db,
14.8°C wb
30.0°C db, 22°C wb
15.0°C db,
13.9°C wb
System Parameters
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
• Outdoor Conditions – Hot: 31°C db, 27°C wb
– Cold: -10 °C
• Internal Design Conditions – 29.5°C db, 21.5°C wb
• New Outdoor Conditions – 41°C db, 33.4°C wb
O
M
W ADP
S
E
31°C db
27°C wb
29.5°C db, 21.5°C wb
17.5°C db,
14.8°C) wb
N.O
41°C db,
33.4°C wb
Higher Ambient
Temperature
Moore Cooling Capacity
Higher Fresh Air
Temperature
More Heat Conducted
Higher Compartment
Heat Load 30.0°C db,
22.2°C wb
15.0°C db,
13.9°C wb
Upgrading the System Using Standard Chilled Water Temperatures
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
O
M
ADP S
E
41°C db,
33.4°C wb
32.5°C db
24.4°C wb
17.5°C db,
14.8°C wb
15.0°C db
13.9°C wb W
29.5°C db,
22.0°C wb
• Chilled Water Temperatures Supply : 6.5°C Return: 13.5°C ΔT: 7°C
O
M
W
ADP
S
E
31°C db
27°C wb
29.5°C db
22.0°C wb 17.5°C db
14.8°C wb
15.0°C db,
13.9°C wb
30.0°C db
22.2°C wb
Upgrading the System Using Standard Chilled Water Temperatures
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Upgrade AHU (Fan + Coil +
Heater)
Upgrade CW Flow
Rate
Upgrade CW
Piping
Higher Fresh Air
Temperature
Upgrade CW Pump
Higher Heat Load
More Air Flow
Upgrade Ducting
Upgrade Chiller
76.5 kW 87.62 kW
Total Heat
Load
4 m3/s 4.7 m³/s Air Flow
120 kW 184.5 kW Cooling Capacity
4.1 l/min 6.3 l/s
Chilled Water
Flow Rate
18%
54%
54%
15%
Lower Chilled Water Supply Temperature
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
O
M
AD
P
S
E
41°C db,
33.4°C wb
32.5°C db
24.4°C wb
17.5°C db
14.8°C wb
15.0°C db
13.9°C wb W
29.5°C db,
22.0°C wb
• Chilled Water Temperatures Supply : 4°C Return: 13.5°C ΔT: 9.5°C
O
M
AD
P
S
E
41°C db,
33.4°C wb
33°C db
24.1°C wb
15.0°C db
12.8°C wb
12.5°C db
11.8°C wb W
30.1°C db
19.8°C wb
Lower Chilled Water Supply Temperature
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
76.5 kW 87.62 kW
Total Heat
Load
4 m3/s 3.75 m3/s Air Flow
120 kW 166.3 kW Cooling Capacity
4.1 l/min 4.1 l/s
Chilled Water
Flow Rate
-6%
39%
0%
15%
Upgrade AHU (Fan +
Coil+Heater)
Upgrade CW Flow
Rate
Upgrade CW
Piping
Higher Fresh Air
Temperature
Upgrade CW Pump
Higher Heat Load
More Air Flow
Upgrade Ducting
Upgrade Chiller
X
X
X X
Lower Air Temperate
Supply
Upgrade Cooling Coil
Capacity
Air-to-Air Energy Recovery
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
O
M
ADP S
E
32.5°C db
24.4°C wb
15.0°C db
12.8°C wb
12.5°C db
11.8°C wb W
30.1°C db
19.8°C wb
OE 34.0°C db
26.7°C wb
41°C db,
33.4°C wb
Out Door Air 31.0°C db, 27.0°C wb
Compartment Exhaust Air 29.5°C db 21.5°C wb
Out Door Air 41.0°C db, 33.4°C wb
Compartment Exhaust
29.5°C db, 21.5°C wb
Fresh Air Supply 34.0°C db, 26.7°C wb
Exhaust Air 36.6°C db 28.0°C wb
ERV
70%
Sensible
56.7% Total
Cooling Enthalpy -23%
Air Conditioning Upgrade Summary
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
120 kW 128.3 kW 7%
120 kW 184.5 kW
Cooling Capacity
54%
120 kW 166.3 kW 39%
• Standard CW temperature
– Upgrade all main components
• Lower CW Supply temperature
– Upgrade chiller plant
• Energy recovery units
– Increase in efficiency
EEinS2015 - International Conference “ENVIRONMENT & ENERGY in SHIPS 2015”
Robin Steward [email protected]
Younus Abbas [email protected]