Title: Lecture Objectives:
1Lecture Objectives
- Learn about
- Pumps and
- System Curves
-
2Hydronic Terms
- Head loss
- Open-loop vs. closed loop
- Open System
- Closed System
h
Pump
Cooling coil in AHU
Chiller
Pump
3Is this open or closed system ?
Cooling towers
4Relationship between velocity in a pipe and
pressure drop
?p v2 ?p Constant v2
Required power (P) for the pump
P V ?p P power W,
V volume flow rate m3/s,
v velocity m/s
?p pressure drop Pa
?p v2 (?p V2 when same pipe
is used) P V V2 when same pipe is used P
V3 P2/P1 (V2/V1)3 For the same
pipe When different pipe is used for the same
flow rate For the same flow rate V Reduction of
D
smaller pipe
larger pipe
?p Pa or ft water
P2/P1 (D1/D2)4 - for the same flow rate or
50 smaller diameter of the pipe for the same
flow rate wee have 4 times larger velocity 16
times larger pressure drop and 16 times lager
power for the pump
v m/s or fpm
5Head Loss
6Fittings
7Pumps
- Raise pressure and produce flow
- Main type
- Centrifugal
Example of Turbine pump
Base mounted
Inline
Reading (textbook) Page 3-36 - 3-45
8Pump curves
- NPSHR Net Positive Suction Head Required
9(No Transcript)
10Changing Pump Speed
11Net Positive Suction Head(cavitation)
12Curve for Multiple Pumps
13System Curves
?p
?p
AB
AB
B
A
B
A
V
A
B
V
A
B
Parallel
Serial
14Find a system curve for this plumbing
configuration
15Primary/Secondary and Tertiary Pumping
(schematics AB below)
16System balancing
AHU1
AHU2
HC1
HC2
100 ft
1000 ft
10 gpm
2 gpm
10 ft
pump
BOILER
17Valves
- Section 5-14 and 6-15 in the textbook
- Types
- Butterfly Valves
- Ball Valves
- Globe Valves
- Three way valves
18Valve Sizing and Flow Coefficient
Cv value
in liter/hour or.
in Pa
Control Valve Selection For Hydronic Systems
reference http//www.google.com/url?satrctjq
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2Fdownload.php3Ffile3Dhegberg.pdfeiIvcqU_O1KM
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19Control Valve Selection For Hydronic Systems
Before DC we tried to do this
Valve authority