Thermal Transfer Systems K Series - Manual (Page 3)

K
[email protected] 262.554.8330 www.thermaltransfer.com
82
W
A
T
E
R C
O
O
L
E
D
K
Piping Diagrams
Single Pass Model
Two Pass Model
A = Hot fluid to be cooled
B = Cooled fluid
C = Cooling water in
D = Cooling water out
Selection Procedure
Performance Curves are based on 100SSU oil leaving the cooler 40°F
higher than the incoming water temperature (40°F approach temperature).
Step 1 Determine the Heat load. This will vary with different systems,
but typically coolers are sized to remove 25 to 50% of the input
nameplate horsepower. (Example: 100 HP Power Unit x .33 = 33
HP Heat load.)
If BTU/Hr. is known: HP = BTU/Hr
2545
Step 2 Determine Approach temperature.
Desired oil leaving cooler °F – Water Inlet temp. °F = Actual
Approach
Step 3 Determine Curve Horsepower Heat load. Enter the
information from above:
HP heat load x 40 x Viscosity = Curve
Actual Approach Correction A Horsepower
Step 4 enter curves at oil flow through cooler and curve horsepower.
Any curve above the intersecting point will work.
Step 5 Determine oil pressure Drop from Curves. Multiply pressure
drop from curve by correction factor B found on oil viscosity
correction curve.
l
= 5 PSI; n = 10 PSI; s = 20 PSI.
Oil Temperature
Oil coolers can be selected by using entering or leaving oil tempertures.
Typical operating temperature ranges are:
Hydraulic Motor Oil
110°F - 130°F
Hydrostatic Drive Oil 130°F - 180°F
Lube Oil Circuits 110°F - 130°F
Automatic Transmission Fluid 200°F - 300°F
Desired Reservoir Temperature
return line Cooling: Desired temperature is the oil temperature
leaving the cooler. This will be the same temperature that will be found
in the reservoir.
off-line recirculation Cooling loop: Desired temperature is the
temperature entering the cooler. In this case, the oil temperature change
must be determined so that the actual oil leaving temperature can be found.
Calculate the oil temperature change (Oil
#
T) with this formula:
Oil
#
T=(BTU’s/Hr.)/GPM Oil Flow x 210).
To calculate the oil leaving temperature from the cooler, use this formula:
Oil Leaving Temperature = Oil Entering Temperature - Oil
#
T.
This formula may also be used in any application where the only temperature
available is the entering oil temperature.
oil pressure Drop: Most systems can tolerate a pressure drop through the
heat exchanger of 20 to 30 PSI. Excessive pressure drop should be avoided.
Care should be taken to limit pressure drop to 5 PSI or less for case drain
applications where high back pressure may damage the pump shaft seals.
C
B A
D
B A
C
D
C
B A
D
B A
C
D
50 60 70 80 90100 150 200 250 300 400 500
.5
.6
.7
.8
.9
1
2
3
4
5
1.5
2.5
OIL VISCOSITY CORRECTION MULTIPLIERS
OIL VISCOSITY - SSU
VISCOSITY CORRECTION
A
B