basic heat transfer concepts
TRANSCRIPT
©2006 Armstrong International, Inc.
®
Basic Heat Transfer ConceptsBasic Heat Transfer Concepts
2““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Basic Heat Transfer ConceptsBasic Heat Transfer Concepts
And Their Relationships to Heating Coil Selection
TTAirAir
TTSteamSteam
TTsteamsteam >>> T >>> TAirAir
3““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Heat TransferHeat Transfer• Only occurs when there is a temperature
difference
• Flows faster when this difference is higher
• Always flows from high to low temperature
• Is greater with greater surface area
• Some materials transfer heat better than others
4““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Heat Flows from High to LowHeat Flows from High to Low
TTAirAir
TTSteamSteam
TTsteamsteam >>> T >>> TAirAir
5““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Thermal Conductivity of Common Coil Thermal Conductivity of Common Coil MaterialsMaterials
Material Thermal Conductivity
Copper 2724
Aluminum 1536
Steel 314
Cupro-Nickle 90/10 310
Cupro-Nickle 70/30 200
Stainless Steel 108
6““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
To Get More Heat Transfer From Bare To Get More Heat Transfer From Bare Tubes . . .Tubes . . .
Add Fins to Increase Surface Area
7““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Relative Heat Transfer:Relative Heat Transfer:Identical Coils w/Different Tube MaterialsIdentical Coils w/Different Tube Materials
Tube Material Relative HT Capacity
Copper 1.00
Aluminum 1.00
Steel 0.98
Stainless Steel 0.95
8““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Relative Heat Transfer:Relative Heat Transfer:Identical Coils w/Material Combinations*Identical Coils w/Material Combinations*
Tube Material Fin Material Relative HT Capacity
Steel Copper Keyfin 1.05
Steel Aluminum Keyfin 1.00
Stainless Steel Aluminum Keyfin 0.94
Steel Steel L Fin 0.92
Stainless Steel Stainless Steel L Fin 0.58
*At 800 FPM, 7FPI & 55 psig
9““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Heat Transfer EquationHeat Transfer EquationQ = U x A x LMTD
where
Q = Heat Transfer Rate (BTU/hr)
U = Heat Transfer Coefficient (BTU/hr/ft2/F)
A = Surface Area (ft2)
LMTD = Log Mean Temperature Difference (b/w the Steam and the Air)
10““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
©2002 Armstrong International, Inc.
Assembly ConceptsAssembly Concepts
11““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Bare Tube CoilsBare Tube Coils
Heat Exchange = U x Surface Area x T
Surface Area 1'' Pipe = 1 Sq Ft / Linear Ft
12““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Extended Surface CoilsExtended Surface Coils
Fin Area >>>>> Tube Area Tube is Irrelevant in Heat Transfer
Fin Element
Plate Fin Wound Fin
13““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Coil ConstructionCoil Construction
1, 2, and 3 Row Coils
Cond. Conn.
Cond. Header
Finned Tube
Steam Header
Steam Conn.
6 Tubes in the Face4 Tubes in the Face
7 FPI
1 Inch4 FPI
14““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Casings and Air BafflesCasings and Air Baffles
Coil Casings
Air Baffles
FlangesCasing Depth
Side Baffle
Header Baffle
Mounting Holes
15““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Coil Casing TypesCoil Casing Types
Turned-Out FlangeStandard Flange for Duct-Mounted Coils
Turned-In FlangeUsed w/ Removable Coils or Where mounting holes are not needed & smooth casing face is wanted
Dimensions & Spacing7/16"
1-1/2” 3/4”
16““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Removable (Drawer) CoilsRemovable (Drawer) Coils
• Core installed in a casing w/ flanges on 3 sides and a mounting place on the 4th side
• Coil slides into outer casing like a drawer
Bolt Holes
Lifting Lug Mounting Plate
17““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Coil ConfigurationCoil Configuration
Air Inlet
Air Outlet
Steam
Horizontal Air Flow
Horizontal Tubes
Vertical Tubes
Condensate
18““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Coil ConfigurationCoil Configuration
Vertical Up Air Flow Horizontal Tubes
Vertical Down Air Flow Horizontal Tubes
Air Inlet Side
Air Outlet Side
Air Outlet Side
Air Inlet Side
19““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Parallel Multiple CoilsParallel Multiple Coils
20““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Series Multiple CoilsSeries Multiple CoilsSteam Supply End
Air Flow
Condensate Return End
21““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
4 Coils in Parallel x 3 Coils in Series• 12 Coils Total• Drain each coil separately• 12 Traps may discharge to common Header
Multiple Coil InstallationMultiple Coil Installation
• Common steam supply OK
22““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Heavy Duty ConstructionHeavy Duty ConstructionMin. 0.016” Thick Finson 12 Ga. CS 0.109” Thick Tubes
12 Ga. Casing and Baffles
Sch 80 Connections
Sch 40 Headers
250 psig Standard Pressure Rating
23““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Heavy Duty ConstructionHeavy Duty Construction• Header, Connections &
Tubes (wetted parts) Same Material• No Galvanic Corrosion
• All Joints Welded• No Leaks
• Thicker Materials• Fights Corrosion
Model Number SelectionModel Number Selection
Extended Surface (Fin Tube) Heating Extended Surface (Fin Tube) Heating CoilsCoils
26““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Which Fin Type?Which Fin Type?Standard KeyFin• Tight joint over wide
temperature range
• Best for dissimilar tube and fin materials
27““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Which Fin Type?Which Fin Type?L-Fin• L-shaped foot tension wound
over knurled tube• Best for same material tubes &
fins• Large contact area for high
heat transfer• Some corrosion protection for
tube
28““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Tube MaterialsTube MaterialsCarbon Steel Affords both strength & corrosion resistanceStandard 12 Ga A-214 ERW (1” or 1½” OD) Optional 10 Ga A-214 ERW
10 Ga or 12 Ga A-179 Seamless
Stainless Steel (304L or 316L)When corrosive steam is present or when ideal piping & trapping practices cannot be followed14 Ga (1” OD) & 12 Ga (1½” OD)
29““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Fin MaterialsFin MaterialsSteel Fins stand up against aggressive cleaning0.024” Thick on 1” OD or 1 1/2” OD Tubes0.036” Thick on 1 ½” OD Tubes
Aluminum Fins provide the best overall value0.020” Thick Keyfin on all Tube Sizes0.030” Thick Keyfin on all Tube Sizes
Stainless Steel Fins fight high external corrosion0.020” Thick Type 304L & 316L on 1” OD Tubes
Copper Fins provide the best heat transfer0.016” Thick on All Tube Sizes
30““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Conns/Headers/CasingConns/Headers/CasingHeadersSame Material As Tubes With Welded Construction
ConnectionsSteel: Sch 80 (screwed) or Sch 40 (flanged)Stainless Steel: Sch 40 (screwed) or Sch 10 (flanged)
Casing12 Ga. Galvanized Steel or 12 Ga Stainless Steel
31““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Coil TypeCoil Type
• Standard (Type S)
• Centifeed (Type C)
• Tendam (Type T)
• Centifeed Tandem (Type P)
Type S coils are available with opposite-end connections only
Type C coils are available with same-end connections only
AIR FLOW
2-Row Standard Coil 2-Row Centifeed Coil
AIR FLOW
Type T coils have opposite-end connections
Type P coils have same-end connections
AIR FLOW
35““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
Armstrong PromiseArmstrong PromiseWe provide intelligent system solutions that
improve utility performance, lower energy consumption, and reduce environmental
emissions . . . while providing an “enjoyable experience”!
35““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®
®®
““Expect many Expect many enjoyable experiencesenjoyable experiences!”!”David M. ArmstrongDavid M. Armstrong
®