Ice Pond Refrigeration System

cypriotcamelUrban and Civil

Nov 29, 2013 (3 years and 10 months ago)

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Chilled Engineering Systems

“Helping You Be Cool”

Ice Pond Refrigeration System

Derek Britten

Roger Connolly

Ben Francis

Adam Trudeau

Steve Vines

Final Presentation to the Mechanical Engineering

Faculty, Students, Clients and Guests

April 7, 2005

CO
2

Emissions Reductions


2002 world FF emissions



24.5 billion metric tonnes




0.703 kg of CO
2

emitted per
KWh of energy produced



Environmental stewardship



“One Tonne Challenge”

www.ge
-
at.iastate.edu

System Overview


Evaluate the effectiveness of an ice pond system


Under development in Norway, Japan


Potential to save energy and lower emissions


Kyoto Protocol


System was created to compare results to vapor
compression system

System Components


Ice Reservoir


Heat Exchanger & Support


Reservoir Cover


Fan Coil Unit (FCU)

Selected Pond


12 foot diameter


3 feet high


8 tonnes of ice


Double liner


Water tight vinyl


Protective tarp

Selected HX Support


1” x 4” wood planks


2” x 4” wood spacers


¼” steel flat bars


Ice block support

Selected Heat Exchanger


1” M copper piping


6” pipe spacing


Length = 51.7m


20% PG mix

FCU Selection

System Balancing


Load Selection


Cooling Load: 12000Btu/hr per 500ft
2

(USDOE 2004)


½ HVAC Lab


300ft
2
2110W


Q
in

= 2000W





Trane FCU vs. CES HX



FCU Selection

Model Chosen

4 pass, 2 row horizontal FCU

Ice Pond Cover



Design:



Self weight



1.8kPa snow load



Result:



No significant snow
accumulation



Withstood all
environmental conditions

Insulation


Heat transfer major concern


Ice preservation during summer


All reservoir components will be insulated


Sub
-
floor


Reservoir wall


Protective cover


Pipes and hoses

Ice Making


Began Feb. 17


Delayed due to warm temps
-

highs of 7
°
C


Slow initial production rates

Ice Making


Ice farms employed Feb. 21



Production rate increased 2
-

3x


Ice making completed in two weeks

Finished Product


Core sample
showing layers

Remaining System

Compression Fittings

Remaining System

Interior

Remaining System

Air Separator

Remaining System

Pump & Flow Meter

Measurements


Δ
T across pool inlet and outlet


Δ
T across FCU inlet and outlet


Control volume temperature


Power consumed by system

Pool
FCU
Q
Q


sys
FCU
P
Q
COP

Q = mc
p
Δ
T

Measurements


10 thermocouples located throughout system

Control Volume

Closed Loop Testing


3 short 2 hour tests


One 24 hour test


Test with maximum flow rate = 2.3gpm &
2100W heat input


Closed Loop Temperatures

18 Hour Closed Loop Test - 2100W Heat Input
Temperatures vs. Time
March 25, 2005
-5.0
0.0
5.0
10.0
15.0
20.0
25.0
0
200
400
600
800
1000
Elapsed Time (min)
Temperature (C)
Inside Amb.
Pool Inlet
Mid. HX
Pool Outlet
Melt Water
Outside Amb.
FCU Inlet
FCU Outlet
FCU Air
Large Control
Volume
Closed Loop Power

18 Hour Closed LoopTest - 2100W Heat Input
Cooling Power, COP and Thermal Efficiency vs. Time
March 25, 2005
1000
1250
1500
1750
2000
2250
2500
2750
3000
0
200
400
600
800
1000
Elapsed Time (min)
Cooling Power (W)
0
1
2
3
4
5
6
7
8
9
10
qFCU
qPool
COP
System
Efficiency
COP and System Efficiency
Closed Loop Testing


24 hours


Average FCU cooling rate =
1660W


Average pool cooling rate =
1989W


Average COP =
7.22


Average system efficiency =
83.68%


Estimated
400 kg

of ice melted


Average control volume temp =
20.94
°
C

Open Loop


Converted system to open loop


bypassed heat
exchanger due to mild temperatures



Compare systems


Flow rate increased


2.9gpm


Less head loss


Less viscous

Open Loop Testing




Same 2 hour tests as closed loop


One 2 hour test at maximum flow rate


One 24 hour test


Test with maximum flow rate = 2.9gpm &
2500W heat input


Open Loop Temperatures

24 Hour Open Loop Test - 2500W Heat Input, Maximum Flow Rate
Temperatures vs. Time
March 29, 2005
0.0
5.0
10.0
15.0
20.0
25.0
0
200
400
600
800
1000
1200
1400
Elapsed Time (min)
Temperature (C)
Inside Amb.
Pool Inlet
Pool Outlet
Melt Water
Outside Amb.
FCU Inlet
FCU Outlet
FCU Air
Large Control
Volume
Open Loop Power

24 Hour Open Loop Test - 2500W Heat Input, Maximum Flow Rate
Cooling Power, COP and Thermal Efficiency vs. Time
March 29, 2005
1500
1750
2000
2250
2500
2750
3000
3250
3500
0
200
400
600
800
1000
1200
1400
Elapsed Time (min)
Cooling Power (W)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
qFCU
qPool
COP
System
Efficiency
COP and System Efficiency
Open Loop Testing


24 hours


Average FCU cooling rate =
2264W


Average pool cooling rate =
2892W


Average COP =
9.84


Average system efficiency =
78.45%


Estimated
815 kg

of ice melted


Average control volume temp =
19.35
°
C

Project Assessment

Design Requirement

Delivered To Client

Create Working Model to Evaluate
Ice Pond System

Yes

Volume of Approximately 10


12 m
3

10 m
3

Reservoir

Overall HX Heat Transfer U
≈ 100W/m
2
K

U = 130W/m
2
K

Cool at a Rate of 2kW

Max Rate of 2.27kW

System Efficiency of 30%

System Efficiency of 80%

Budget = $5000

Total Cost = $5413.51

COP > COP V/C

COP = 10 (3x Greater)

Conclusions


All tests had a COP > 5


Little to no transient operating zone


reached
steady state quickly


More melt water = less performance


Open loop is better than closed loop


Δ
T between working fluid and air


Mass flow rate


C
p

of working fluid

Q = mc
p
Δ
T

Conclusions


Need a powerful system for low temperatures


No energy consumed for ice making


System efficiency high because of cool
ambient temperatures during testing

Budget


Estimated Budget: $5000.00

Actual Costs


Ice Reservoir

$1235.73

Piping and HX’s

$2078.06

Ice/ HX Support

$238.00

Pool Cover

$764.70

Testing Equipment

$826.59

Miscellaneous

$270.42

Grand Total

$5413.51

CO
2

Emissions Reductions


Environmental stewardship



“One Tonne Challenge”




OUR SYSTEM



Reduced by
3x
!

www.ge
-
at.iastate.edu

Recommendations


Full scale model


Melt water


No heat exchanger


Increase space between pool inlet & outlet


Colder outlet temperatures


Higher flow rates


Turbulent instead of laminar flow


Increases rate of heat transfer


More durable reservoir


Not dependent on vinyl liner


Automated ice making system

Demonstration

Special Thanks To:


Mr. Richard Rachals


Dr. Murat Koksal


Albert Murphy


Greg Jollimore


Dr. Peter Allen


Import Tool Corporation


Jeff MacNeil of Trane


Mike Trudeau of HCDJ

Questions?