Objectives

1
Objectives

• - Finish with pumps and plumbing example

- Learn about district cooling and heating
systems
2
System Curves
?p
?p
AB
AB
B
A
B
A
V
A
B
V
A
B
Parallel
Serial
3
(No Transcript)
4
System balancing
AHU1
AHU2
HC1
HC2
100 ft
1000 ft
10 gpm
2 gpm
10 ft
pump
BOILER
5
Pumps

• Raise pressure and produce flow
• Main type
• Centrifugal

Example of Turbine pump
Base mounted
Reading (textbook) Page 3-36 - 3-45
Inline
http//www.taylor-engineering.com/downloads/coolto
ols/EDR_DesignGuidelines_CoolToolsChilledWater.pdf
6
Curve for Multiple Pumps
7
Changing Pump Speed
8
HW5 Find a system curve for this plumbing
configuration
9
Primary/Secondary and Tertiary Pumping
Reading Assignment
Taylor, S., P. Dupont, B. Jones, T. Hartman and
M. Hydeman. 2000. Chilled water plant design
guide. San Francisco Pacific Gas Electric
Company. http//www.taylor-engineering.com/downloa
ds/cooltools/EDR_DesignGuidelines_CoolToolsChilled
Water.pdf
10
Hydronic systems for district cooling/heating and
buildings
Constant-Flow System, Single Chiller, Single Coil
Constant-Flow System, Single Chiller, Multiple
Coils
Mixing valve that control by-pass flow Major
pumping force is the chiller pump
11
Control of coil temperature
Mixing valve that control the flow through the
coil Flow Variation as a Function of Valve
Position
Same pressure drop like a cooling coil
Major pumping force is the chiller pump
12
Multiple chiller (or boilers)
Serial
Parallel
13
Primary-Loop Only VariableSpeed Flow
Single chiller
Multiple chillers
14
Primary and Secondary Loop Variable Flow Design
Parallel chillers
Serial chillers
15
Large Plant or Building Distribution Systems
Primary/Secondary Loops with Variable Flow and
Distributed Pumping
16
Primary/Secondary and Tertiary Pumping
17
Primary Pump Arrangements
Dedicate a pump for each chiller
Provide a common header for the pumps
18
Coil Pumping Strategies
Variable speed pumps vs. Single pas Valve vs.
Mixing valves vs. Diverting Valves
19
Impact of plumbing on acooling coil
20
Plumbing Arrangement in Buildings hydronic
systems
Radiators
Fan coil systems
Baseboard heaters
21
Valves

• Section 5-14 and 6-15 in the textbook
• Types
• Butterfly Valves
• Ball Valves
• Globe Valves
• Three way valves

22
Valve 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
esrcssourcewebcd1cadrjauact8ved0CCUQFj
AAurlhttp3A2F2Fbookstore.ashrae.biz2Fjournal
2Fdownload.php3Ffile3Dhegberg.pdfeiIvcqU_O1KM
uE2AWgloHgDAusgAFQjCNFRAMzPnbzDpAluhyk4l8u_SKKTd
w
23
Control Valve Selection For Hydronic Systems
Before DC we tried to do this
Valve authority