12 Chiller Performance.ppt

SECTION 12
Chiller
Performance

European Training Center Of Excellence EUR - TRG - RTHC 1 2
Chiller Performance

Performance
Coverage
• Factors That Affect Performance
– System Design Factors
• Hardware Design Factors
– Type of Motors
– Drive Systems
– Refrigerants
– Heat Exchangers
• Measuring Operating Performance
– Sales Order Form
– Formulas
– Taking Measurements
• Examples Of Operational Changes
– Water Flow
– Contamination

Performance,
What is it ?
Getting What You Pay For or
Hitting Your Target Consistently

Technologies
Dictate
Performance
• Heat Transfer ( Water to Refrigerant )
• Refrigerant Thermodynamic Properties ( Cycle Efficiency )
• Drive Train ( Electrical and Mechanical Energy
Transmission Efficiency )
• Compressible Fluid Dynamics ( Compressor Efficiency )

Heat Transfer
• Replacement of CFC’s
– Refrigerant Efficiency
• Evaporator Design Changes
– Surface Area
• Tube Design Changes
– Texture Inside / Outside
• Condenser Design Changes
– Surface Area
• Better Water Treatment
– Tube Fouling
• Better Water Pump Design
1970 1975 1980 1985 1990 1994 1995
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1970 1975 1980 1985 1990 1994 1995
Kw/Ton

Cycle Efficiency
• Refrigerant Thermodynamics
– HCFC - 123 .5801 HP / Ton
– HCFC - 123 8.1303 kWcool / kWelec
– HCFC - 123 / Economizer .5569 HP / Ton
– HCFC - 123 / Economizer 8.4690 kWcool / kWelec
– HFC - 134a .6172 HP / Ton
– HFC - 134a 7.6416 kWcool / kWelec
– HCFC - 22 .6150 HP / Ton
– HCFC - 22 7.6689 kWcool / kWelec
1 HP = 0.7457 kWelec and 1 Ton = 3.517 kWcool

Drive Train Efficiency
• Hermetic Direct Drive
Compressor
• Hermetic Gear Driven
Compressor
• Open Gear Driven
Compressor
Gear Set
Motor
Gear
Shaft
Seal
Coupling
Motor
Moto
r
Impellers
Trane Multi - Stage Compressor

Compressor
Efficiency
• Impeller Design Changes
• Diffuser Design
• Volute Design
• Reduction of Pressure Drop
• Multiple impeller design Vs.
Single Stage impeller design
Compressors
• Economizer Stages

Measuring Operating
Performance
• The Sales Order Form
• Measurement Formulas
• Taking Measurements

Serviceability
Affects Performance
• Water Flow - Condenser
• Water Flow - Evaporator
• Type of Refrigerant
• Water Temperature
• Air In The System
• Economizers
What do you Measure ?

Start With The
Unit Model and
Serial Number
Trane
Old Order Write - Up Sheet
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
Comments:
Recommendations:
Bill of Material
New Unit Specifications
are Obtained from
Trane Company

Order Write - up sheet
• Evaporator Delta “T”
• Evaporator Passes
• Fluid Type
• Fouling Factor
• Evaporator Delta “P”
• Evaporator GPM
• Max. LRA
• RLA at Motor
• Motor kW
• Refrigerant Charge
• Evaporator Approach
• Condenser Delta “T”
• Condenser Passes
• Fouling Factor
• Condenser Delta “P”
• Condenser GPM
• Design Duty “Tons”
• kW Per Tons
• Voltage
• Frequency
• Refrigerant
• Max. Sound

What Do You Do With
This Information ?
Trane
Old Order Write - Up Sheet
1
2
3
4
5
6
7
8
9
12
13
14
15
16
17
18
19
20
21
22
26
27
28
29
30
31
32
33
34
35
36
Comments:
Recommendations:
• Evaporator Delta “T”
• Evaporator Passes
• Fluid Type
• Fouling Factor
• Evaporator Delta “P”
• Evaporator GPM
• Max. LRA
• RLA at Motor
• Motor kW
• Refrigerant Charge
• Evaporator Approach

Compare Current To
Design
Measurements
The Term “Refrigeration” means,
To move heat from a place you don’t
want it, to a place where it’s not objectionable.
Heat Balance
( Net Even )
COND.
EVAP. MOTOR
This
=
This

Heat Balance
Formula
GPM X TD + ( K.W. ) X 3413 = GPM X TD
24 12,000 24
Tons + Tons = Tons

Heat Balance
Formula
Evaporator + Motor = Condenser
840 X 10 + ( 193) X 3,413 = 1,050 X 9.32
24 12,000 24
[350 TONS + 54.9 TONS]
404.9 Tons = 407.75
ARI = + - 5%
407.75
404.9
2.85 Tons Difference
2.85
407.75
X 100 = .70%

Heat Balance
Formula
Cooling Electrical Condenser
Capacity Power Capacity
kW + kW = kW

Heat Balance
Formula
m (kg) x Cp (4.18 kJ) x DT (°C) + P elec (kW) x 0.8
(s) (kg x°C)
kW cool + kW comp =
m (kg) x Cp (4.18 kJ) x DT (°C)
(s) (kg x°C)
kW cond
=

Cool Tower Water In
Warm Condenser
Water Out
Building
Return Water
Cold Evaporator
Water Out
Approach
Approach
Lift
=
Delta “P”
=
Delta “T”
Orifice
Compressor
Condenser
Evaporator
Condenser Saturated Liquid
Evaporator
Saturated Mixture
Approach and Lift

Warm Condenser
Water Out
Building
Return Water
45 Deg. Out
55 Deg. In
Cool Tower Water In
Cold Evaporator
Water Out
Approach
Approach
Lift
=
Delta “P”
=
Delta “T”
Orifice
Compressor
Condenser
Evaporator
Saturated Mixture
40 Deg.(18.2 In. Vacuum)
85 Deg.
In
95 Deg. Out
100 Deg.(6.3 PSI)
5 Deg.
5 Deg.
Approach and Lift

Warm Condenser
Water Out
Building
Return Water
7°C Out
13°C In
Cool Tower Water In
Cold Evaporator
Water Out
Approach
Approach
Lift
=
Delta “P”
=
Delta “T”
Orifice
Compressor
Condenser
Evaporator
Saturated Mixture
29°C In
35°C Out
37.7°C (0.42 bar Pe)
2.7°C.
2.7°C.
Approach and Lift
4.3°C (-0.62 bar Pe)

Estimating kW
1. Determine kW from a kW or PF meter
2. Calculate kW Using Average Volts, Average Amperes
and Motor Power Factor
Real Power in kW = V x A x 1.73 x PF
1000
Example : 480 x 274 x 1.73 x .85 = 193.4 kW
With Power Factor Capacitors = 90 to 95 %
3

Converting PSIG to
Pressure in Feet Of Head
 1 PSIG = 28 Inches Water Column
 28 Inches W.C. = 2.3 Feet of Head
 Delta “ P “ = PSIG IN - PSIG OUT
Delta “P” = PSIG IN
- PSIG Out
PSIG Net Pressure Drop
Example:
15.0 PSIG In
7.5 PSIG OUT
7.5 PSIG Net
7.5 X 2.3 = 17.25 Ft. of Head

Converting PSIG to
Pressure in Feet Of Head
 Pe = 1 bar = 10.2 mCE
 Delta “ P “ = Pe IN - Pe OUT
Delta “P” = Pe IN - Pe OUT =
Pe Net Pressure Drop Example:
1 bar Pe IN
- 0.5 bar Pe OUT
0.5 bar DP Net

GPM Pressure Drop
Chart
Feet
of
Head
GPM
2 Pass
Size 5
Condenser
Maximum speed Rate 11 Ft / sec
Minimum speed Rate 3 Ft / sec
25
20
15
10
5
0
0 50 100 150 200 250 300 350 400
200 GPM

GPM Pressure Drop
Chart
m W.C.
m3/h
2 Pass
Size 5
Condenser
Maximum speed Rate 33 m/s
Minimum speed Rate 9 m/s
10
8
6
4
2
0
0 10 20 30 40 50 60 70 80
45 m3/h

How Performance Can
Be Affected By
Components
• Economizers
• Compressors and Motors
• Heat Exchangers
– Condensers
– Evaporators

Economizers
• CVHE 3 Stage has a 2 Stage
Economizer
• CVHF 2 Stage has a Single
Stage Economizer
• There is an ORIFICE
upstream of 1, Between 1
and 2 and down stream of 2.
• Each Stage has a value of 2
degrees Sub-cooling
1
2
How do you see efficiency ?

Refrigeration Effect
• A = Saturated Liquid Line
• B = Saturated Vapor Line
–1 = 40 F / 4.4°C Evap.
–2 = Superheated Vapor
–3 = Motor & Heat of
Compression
–4 = De-Superheating
–5 = 105 F / 41°C Cond.
–6 = Sub-cooled Liquid
–7 = Expansion Device
–8 = Flash Gas
P
R
E
S
S
U
R
E
Bar Refrigeration
Effect
Subcooled Superheated
A B
1
2
3
4
5
6
7
8
R-22
ENTHALPY
kJ / kg
30
European Training Center Of Excellence

ENTHALPY
kJ / kg
Refrigeration
Effect
Subcooled Superheated
A B
1
2
3
4
5
6
7
8
P
R
E
S
S
U
R
E
P
S
I
A
Pressure
Enthalpy Diagram
R - 22
This diagram is for a Reciprocating
Compressor system.
Note: This chart shows sub-cooling
Centravac units do not have
condenser sub-cooling.

Centravac P / h Diagram
• Less Superheated Gas =
Less
Condenser Surface Area
• No Sub-cooling = Less
Condenser Surface
• Economizer Effect moves the
Saturated Liquid Line Farther
to the Left
• Pressure Gain in the Liquid
line provides a measure of
Sub-cooling at the metering
orifice at the entrance to the
Evaporator.
• Less Energy is used to
produce the same
refrigeration effect
P
R
E
S
S
U
R
E
P
S
I
A
Refrigeration
Effect
A B
1
2
3
4
5
6
7
8
Less
Superheated
Gas
No
Sub-cooling
ENTHALPY
kJ / kg

Compressor and
Motor Efficiency
• Physical Design
– Gear Driven
• 2545 Btu’s/Hr or 746 W per Bearing
• 1 % of Total Transmitted Power
• Single Stage Vs. Multi- Stage
– PCV = 2 Stage
– CVHE = 3 Stage
– CVHB = 2 Stage
– CVHF = 2 Stage
– CV = 2 Stage
• Motor Efficiency
– Wire to Shaft Efficiency of 90 - 96 %
– Seals Absorb 2 Brake Hp.

Gear Driven
Hermetic
• Frictional losses
• Bearing Problems
• Gear Problems
• High Pressure Gas
Problems
• More Parts To Fail
• More Power
Consumption
• 7,000 To 36,000 RPM
 Double gear set
Gear Set
Motor
 5 bearings
2545 x 5 = 12,725 BTU’s Loss
or 746 x 5 = 3730 W = 3.7 kW Loss
2 % Total Transmitted power

Gear Driven Open
Drive
• Frictional losses
• Bearing Problems
• Gear Problems
• High Pressure Gas
Problems
• More Parts To Fail
• More Power
Consumption
• 7,000 To 36,000 RPM
• Coupling Problems
 5 bearings
2545 x 5 = 12,725 Btu’s
or 746 x 5 = 3730 W = 3.7 kW Loss
 Coupling
Alignment Problems
 Gear set
2 % Total Power
 Seal
2 Brake Hp
Gear
Shaft
Seal
Coupling
Motor

Direct Drive Reliability
• 3600 RPM
• Multi-stage Compressor
• Fewer Parts To Fail
• Low Pressure Refrigerant
• Less Friction Loss
• Fewer Bearings
• No Gears
• Less Power Consumption
• No additional heat to the
equipment room
Moto
r
Impellers
Trane Multi - Stage Compressor
.48 to .52 kW / Ton
7.33 to 6.76 kWcool / kWelec

Multiple - Stage
Compressor Efficiency
• Stable operation over a
wide range of
conditions
• Surge Resistant
• Can handle high head
pressure applications
– Heat Recovery
– Ice Storage
– Low Temperature Air
• Lower GPM
requirements for the A/C
water system

Compressor Maps
3 - Stage 2 - Stage 1 - Stage
H
E
A
D
H
E
A
D
FLOW FLOW FLOW
Surge Area
H
E
A
D

Heat Exchangers
Shell and Tube

Heat Exchanger Performance
• Affected By
– Load Reduction
– Water Flow Rate
• Higher Flow
• Lower Flow
– Evaporator Fouling
– Condenser Fouling
– Low Refrigerant

Normal
Example
• 1,000 Ton
or 3517 kW
Machine
• Full Load
• 625 kWelec
• .625 kW / Ton
• R - 123
Water In
85 F / 29°C
Water Out
95 F / 35°C
6.3 PSIG / Pe = 0.4 bar
100 F
37.7°C
Approach 5 F / 2.7 K
Water In
55 F / 13°C
Water Out
45 F / 7°C
18.2" Hg / - 0.62 bar
40 F / 4.3°C
1,000 Tons
kW / Tons =
625 / 1,000 = .625
COP = 5.63
European Training Center Of Excellence 41

Part Load
• Same 1,000
Ton Machine
• 485 kWelec
• .606 kW / Ton
or COP = 5.8
• R - 123
Cooler
Water In
53 F / 12°C
Water Out
45 F / 7°C
17.5" Hg / - 0.59 bar
42 F / 5.3°C
800 Tons / 2814 kW
Less Heat
42

Part Load -
Approach and Lift
Compressor
Orifice
Condenser
Tower In
Orifice
Compressor
Condenser
Tower In
55 F.
10 F.
45 F.
Evaporator
System Return
5 Deg. F. Approach
40 F. Sat Ref.
Evaporator
System Return
3 Deg. F. Approach
53 F.
8 F.
45 F.
42 F. Sat. Ref.
Reduced
Mass Flow
Reduced Lift
Full Mass
Flow
Reduced
Approach

Part Load -
Approach and Lift
Compressor
Orifice
Condenser
Tower In
Orifice
Compressor
Condenser
Tower In
13°C
6 K
7°C
Evaporator
System Return
2.7 K Approach
4.3°C Sat Ref.
Evaporator
System Return
1.7 K Approach
12°C
5 K
7°C
5.3°C Sat. Ref.
Reduced
Mass Flow
Reduced Lift
Full Mass
Flow
Reduced
Approach

1000 Ton Machine
Energy Cost
Full Load
1,000-Ton Load or 3517 kW
[1000 Ton] x [KW / Ton = .625] x [8¢ KWH] = $50.00 / HR
[3517 kW] / [COP = 5.63] x [50 cts kWh] = FF 312.00 per hour
[3000 HR] x [$50.00 HR] = $150,000
[3000 h] x [FF 312.00 per hour] = FF 936 000
•Power Cost - 50 cts / kWh
•Power Cost - 8c / kWh
•3,000 Operating Hours

1000 Ton Machine
Energy Cost
Part Load
800-Ton Load or 2814 kW
[3000 HR] x [$38.78 HR] = $116,340.00
[3000 h] x [FF 243.00 per hour] = FF 729 000
Savings $33,660.00 or FF 207 000

Is Affected By
• Load Reduction
• Water Flow Rate
Higher Flow
Lower Flow
• Tube Fouling
Water Side
Refrigerant Side
• Non-Condensable
• Low Refrigerant
47

Normal
Example
• 500 Ton
or 1759 kW
Machine
• 352 kWelec
• .70 kW / Ton
• COP = 5.00
Water In
85 F / 29°C
Water Out
95 F / 35°C
Water In
55 F / 13°C
Water Out
45 F / 7°C
18.2" Hg (40F) / -0.62 bar (4.3°C)
500 Tons
48
6.3 PSIG(100F) / Pe = 0.4 bar(37.7°C)

High
Condenser
Water Flow
• 500 Ton Machine
• 315 kWelec
• .63 kW / Ton
• COP = 5.58
Water In
85 F / 29°C
Water Out
92 F / 33°C
4.2 PSIG / 0.3 bar
95 F
35°C
Approach 3 F / 2 K
500 Tons

Excess Water Flow
- Approach and Lift
Compressor
Orifice
Condenser
Tower In
Orifice
Compressor
Tower In
55 F.
10 F.
45 F.
Evaporator
System Return
5 Deg. F. Approach
40 F/4.4°C Sat Ref.
Evaporator
System Return
5 Deg. F. Approach
55 F.
10 F.
45 F.
40 F. Sat. Ref.
Full
Mass Flow
Reduced Lift
Same
Approach
95 F
35°C
85 F
29°C
92 F/33°C
85 F/29°C
100 F/37.7°C
Saturated Condenser
6.3 PSIG/0.4bar
5 F/2.7K Approach
95 F/35°C Saturated Condenser
4.6 PSIG/0.3bar
3 F/2K Approach
Full
Mass Flow

500 Ton Machine
Energy Cost
Normal Flow
[3000 HR] x [$28.00 HR] = $84,000
[3000 h] x [FF 176.00 per hour] = FF 528 000

500 Ton Machine
Energy Cost
Higher Water Flow
[3000 HR] x [$25.20 HR] = $75,600
[3000 h] x [FF158.00 per hour] = FF 474 000
Savings $8,400 or FF 54 000

What About Water Pump
Horsepower?

Kilowatts Per Ton
Versus Lift
kW / Ton Lift Motor HP / Ton
Normal

A 1 F / 0.6°C Reduction in Lift
Results in a 1% Reduction
in Motor Kilowatts
55

Is Affected By
• Load Reduction
• Water Flow Rate
Higher Flow
Lower Flow
• Tube Fouling
Water Side
Refrigerant Side
• Non-Condensibles
• Low Refrigerant
56
European Training Center of Excellence

Normal
Example
• 500 Ton
or 1759 kW
Machine
• 352 kWelec
• .70 kW / Ton
• COP = 5.00
Water In
85 F / 29°C
Water Out
95 F / 35°C
Water In
55 F / 13°C
Water Out
45 F / 7°C
18.2" Hg (40F) / - 0.62 bar (4.3°C)
500 Tons
57
6.3 PSIG(100F) / Pe = 0.4 bar(37.7°C)

Lower
Condenser
Water Flow
• 500 Ton Machine
• 350 kW
• .777 kW / Ton
• COP = 4.53
Water In
85 F / 29°C
Water Out
98 F / 36.7°C
7.2 PSIG(103 F) / 0.5bar(39.4°C)
450 Tons / 1583 kW
58

Low Water Flow -
Approach and Lift
Compressor
Orifice
Condenser
Tower In
Orifice
Compressor
Tower In
55 F.
10 F.
45 F.
Evaporator
System Return
5 Deg. F. Approach
40 F. Sat Ref.
Evaporator
System Return
5 Deg. F. Approach
55 F.
10 F.
45 F.
40 F. Sat. Ref.
Full
Mass Flow
Increased Lift
Same
Approach
98F
36.7°C
85 F
29°C
95 F/35°C
85 F/29°C
103 F/39.4°C
Saturated Condenser
7.2 PSIG/0.5bar
5 F/2.7K Approach
100 F/37.7°C Saturated Condenser
6.3 PSIG/0.4 bar
5 F/ 2.7 K Approach
Full
Mass Flow
Same
Approach

500 Ton Machine
Energy Cost
Normal Flow
[3000 HR] x [$28.00 HR] = $84,000
[3000 h] x [FF 176.00 per hour] = FF 528 000

500 Ton Machine
Energy Cost
Lower Water Flow
[3000 HR] x [$31.08 HR] = $93,240
[3000 h] x [FF 194.00 per hour] = FF 582 000
Additional Cost $9,240 or FF 54 000

Heat Exchanger
Performance Is Affected
• Load Reduction
• Water Flow Rate
Higher Flow
Lower Flow
• Tube Fouling
Refrigerant Side
Condenser
Evaporator
• Non-Condensable
• Low Refrigerant

Normal
Example
• 1200 Ton
or 4220 kW
Machine
• 831 kWelec
• .693 kW / Ton
• COP = 5.08
Water In
85 F / 29°C
Water Out
95 F / 35°C
Water In
55 F / 13°C
Water Out
45 F / 7°C
17.8" Hg (41F) / - 0.60 bar (5°C)
Approach 4 F / 2 K
1,200 Tons
63
6.3 PSIG(100F) / Pe = 0.4 bar(37.7°C)

Fouled
Condenser
• 1,200 Ton
or 4220 kW
Machine
• 832 kW Draw
• .770 kW / Ton
• COP = 4.56
Water In
85 F / 29°C
Water Out
93 F / 34°C
6.8 PSIG(102 F) / 0.5 bar (39°C)
Approach 9 F / 5 K
1,080 Tons
3798 kW

Refrigerant Fouling
TUBE- Approach and Lift
Compressor
Orifice
Condenser
Tower In
Orifice
Compressor
Tower In
55 F.
10 F.
45 F.
Evaporator
System Return
5 Deg. F. Approach
40 F. Sat Ref.
Evaporator
System Return
5 Deg. F. Approach
55 F.
10 F.
45 F.
40 F. Sat. Ref.
Full
Mass Flow
Same
Approach
Full
Mass Flow
Same
Approach
93F
34°C
85 F
29°C
Increased Lift
102 F/39°C
Saturated Condenser
6.8 PSIG/0.5bar
9 F/ 5 K Approach
95 F/35°C
85 F/29°C
6.3 PSIG/0.4 bar
5 F/ 2.7 K Approach

1,200 Ton Machine
Energy Cost
Clean Condenser
[1,200 Ton] x [KW / Ton = .693] x [8¢ KWH] = $66.53 / HR
[3000 HR] x [$66.53 HR] = $199,590
[3000 h] x [FF 415.00 per hour] = FF 1 245 000

1,200 Ton Machine
Energy Cost
Fouled Condenser
[1,200 Ton] x [KW / Ton = .770] x [8¢ KWH] = $73.92 / HR
[3000 HR] x [$73.92 HR] = $221,760
[3000 h] x [FF 463.00 per hour] = FF 1 389 000

Heat Exchanger
• Load Reduction
• Water Flow Rate
Higher Flow
Lower Flow
• Tube Fouling
Refrigerant Side
Condenser
Evaporator
• Non-Condensable
• Low Refrigerant

Normal
Example
• 800 Ton
or 2814 kW
Machine
• 564 kWelec
• .705 kW / Ton
• COP = 4.99
Water In
85 F / 29°C
Water Out
95 F / 35°C
Water In
55 F / 13°C
Water Out
45 F / 7°C
17.8" Hg (41F) / - 0.60 bar (5°C)
Approach 4 F / 2 K
800 Tons / 2814kW
69
6.4 PSIG(101F) / Pe = 0.44 bar(38.3°C)

Refrigerant
Fouled
Evaporator
Tubes
• 800 Ton
or 2814 kW
Machine
• 541 kWelec
• .751 kW / Ton
•COP = 4.68
Water In
55 F / 13°C
Water Out
47 F / 8.3°C
720 Tons
18.6" Hg (39F) / - 0.63 bar (3.9°C)

Part Load -
Approach and Lift
Compressor
Orifice
Condenser
Tower In
55 F.
10 F.
45 F.
Evaporator
System Return
5 Deg. F. Approach
40 F. Sat Ref.
55 F.
8 F.
47 F.
Orifice
Compressor
Condenser
Tower In
Evaporator
8 Deg. F. Approach
39 F. Sat. Ref.
Lift
Increased Approach

800 Ton Machine
Energy Cost
Clean Evaporator
[3000 HR] x [$45.12 HR] = $135,360
[3000 h] x [FF 282.00 per hour] = FF 846 000

800 Ton Machine
Energy Cost
Fouled Evaporator
[3000 HR] x [$48.06 HR] = $144,180
[3000 h] x [FF 301.00 per hour] = FF 903 000

Heat Exchanger
• Load Reduction
• Water Flow Rate
Higher Flow
Lower Flow
• Tube Fouling
Water Side
Refrigerant Side
• Non-Condensable
• Low Refrigerant

Normal
Example
• 300 Ton
or 1055 kW
Machine
• 195 kWelec
• .65 kW / Ton
• COP = 5.41
Water In
85 F / 29°C
Water Out
95 F / 35°C
Water In
55 F / 13°C
Water Out
45 F / 7°C
17.8" Hg (41F) / - 0.60 bar (5°C)
Approach 4 F / 2 K
300 Tons / 1055kW
75
6.4 PSIG(101F) / Pe = 0.44 bar(38.3°C)

Non -
Condensable
• 300 Ton
or 1055 kW
Machine
• Non-Condensable
• 300 kW
• 1.25 kW / Ton
• COP = 2.81
Water In
85 F / 29°C
Water Out
92 F / 33.3°C
240 Tons / 844 kW
10 PSIG(105F) / Pe = 0.7 bar(40.6°C)

Trapped Air -
Approach and Lift
Compressor Orifice
Condenser
Tower In
Orifice
Compressor
Tower In
55 F.
10 F.
45 F.
Evaporator
System Return
5 Deg. F. Approach
40 F. Sat Ref.
Evaporator
System Return
5 Deg. F. Approach
55 F.
10 F.
45 F.
40 F. Sat. Ref.
Full
Mass Flow
Increased
Approach
Full
Mass Flow
Same
Approach
92F
33.3°C
85 F
29°C
Increased Lift
105 F/40.6°C
Saturated Condenser
10 PSIG/0.7bar
13 F/ 7.3 K Approach
95 F/35°C
85 F/29°C
6.3 PSIG/0.4 bar
5 F/ 2.7 K Approach

300 Ton Machine
Energy Cost
No Non-Condensable
[3000 HR] x [$15.60 HR] = $46,800
[3000 h] x [FF 98.00 per hour] = FF 294 000

300 Ton Machine
Energy Cost
With Non-Condensibles
[300 Ton] x [KW / Ton = 1.25] x [8¢ KWH] = $30.00 / HR
[3000 HR] x [$30.00 HR] = $90,000
[3000 h] x [FF 188.00 per hour] = FF 564 000

Heat Exchanger
• Load Reduction
• Water Flow Rate
Higher Flow
Lower Flow
• Tube Fouling
Water Side
Refrigerant Side
• Non- Condensable
• Low Refrigerant

Normal
System
• 500 Ton
or 1759 kW
Machine
• 328 kWelec
• .655 kW / Ton
• COP = 5.37
Water In
85 F / 29°C
Water Out
95 F / 35°C
Water In
55 F / 13°C
Water Out
45 F / 7°C
17.8" Hg (41F) / - 0.60 bar (5°C)
Approach 4 F / 2 K
500 Tons / 1759 kW
81
6.4 PSIG(101F) / Pe = 0.44 bar(38.3°C)
500 Tons / 1759 kW

Low
Refrigerant
Charge
• 500 Ton
or 1759 kW
Machine
• 320 kWelec
• .71 kW / Ton
• COP = 4.95
Water In
85 F / 29°C
Water Out
94 F / 34.4°C
Water In
55 F / 13°C
Water Out
46 F / 7.8°C
19.2" Hg (36F) / - 0.65 bar (2.2°C)
450 Tons / 1583 kW
82
5.7 PSIG(99 F) / Pe = 0.39 bar(37.1°C)
450 Tons / 1583 kW

Low Refrigerant Charge
Approach and Lift
Compressor
Orifice
Condenser
Tower In
55 F.
10 F.
45 F.
Evaporator
System Return
5 Deg. F. Approach
40 F. Sat Ref.
55 F.
9 F.
46 F.
Orifice
Compressor
Condenser
Tower In
Evaporator
10 Deg. F. Approach
36 F. Sat. Ref.
Lift
Increased Approach

500 Ton Machine
Energy Cost
Proper Charge
[3000 HR] x [$26.20 HR] = $78,600
[3000 h] x [FF 164.00 per hour] = FF 492 000

500 Ton Machine
Energy Cost
Low Refrigerant Charge
[3000 HR] x [$28.40 HR] = $85,200
[3000 h] x [FF 178.00 per hour] = FF 534 000

Conclusions
• Water Flows Must Be Maintained
• Water Integrity Must Be Maintained
• Chiller Logs Must Be Kept Up to Date And
Monitored
• Chiller Leaks Are Unacceptable
• Proper Instrumentation Must Used And
Maintained
• Poor Performance Costs Big $$$$$Money

12 Chiller Performance.ppt

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to 12 Chiller Performance.ppt

Similar to 12 Chiller Performance.ppt (20)

Recently uploaded

Recently uploaded (20)

12 Chiller Performance.ppt