Thermal Conductivity of some chosen Supplies and Gases

Convective heat transfer
January 31, 2021 0 Comments

Thermal conductivity is a fabric property that describes skill to conduct warmth. Thermal conductivity could be outlined as

“the amount of warmth transmitted by a unit thickness of a fabric – in a path regular to a floor of unit space – because of a unit temperature gradient underneath regular state circumstances”

Thermal conductivity models are [W/(m K)] within the SI system and [Btu/(hr ft °F)] within the Imperial system.

See additionally thermal conductivity variations with temperature and strain, for:  Air,  Ammonia, Carbon Dioxide and Water

Thermal conductivity for frequent supplies and merchandise:

Thermal Conductivity
okay –
W/(m Ok)

Materials/Substance Temperature
25 oC
(77 oF)
125 oC
(257 oF)
225 oC
(437 oF)
Acetals 0.23
Acetone 0.16
Acetylene (fuel) 0.018
Acrylic 0.2
Air, environment (fuel) 0.0262 0.0333 0.0398
Air, elevation 10000 m 0.020
Agate 10.9
Alcohol 0.17
Alumina 36 26
Aluminum
Aluminum Brass 121
Aluminum Oxide 30
Ammonia (fuel) 0.0249 0.0369 0.0528
Antimony 18.5
Apple (85.6% moisture) 0.39
Argon (fuel) 0.016
Asbestos-cement board 1) 0.744
Asbestos-cement sheets 1) 0.166
Asbestos-cement 1) 2.07
Asbestos, loosely packed 1) 0.15
Asbestos mill board 1) 0.14    
Asphalt 0.75
Balsa wooden 0.048
Bitumen 0.17
Bitumen/felt layers 0.5
Beef, lean (78.9 % moisture) 0.43 – 0.48
Benzene 0.16
Beryllium
Bismuth 8.1
Bitumen 0.17
Blast furnace fuel (fuel) 0.02
Boiler scale 1.2 – 3.5
Boron 25
Brass
Breeze block 0.10 – 0.20
Brick dense 1.31
Brick, hearth 0.47
Brick, insulating 0.15
Brickwork, frequent (Constructing Brick) 0.6 -1.0
Brickwork, dense 1.6
Bromine (fuel) 0.004
Bronze
Brown iron ore 0.58
Butter (15% moisture content material) 0.20
Cadmium
Calcium silicate 0.05
Carbon 1.7
Carbon dioxide (fuel) 0.0146    
Carbon monoxide 0.0232
Forged iron
Cellulose, cotton, wooden pulp and regenerated 0.23

Cellulose acetate, molded, sheet

0.17 – 0.33
Cellulose nitrate, celluloid 0.12 – 0.21
Cement, Portland 0.29
Cement, mortar 1.73
Ceramic supplies
Chalk 0.09    
Charcoal 0.084
Chlorinated poly-ether 0.13
Chlorine (fuel) 0.0081
Chrome Nickel Metal 16.3    
Chromium
Chrom-oxide 0.42
Clay, dry to moist 0.15 – 1.8    
Clay, saturated 0.6 – 2.5    
Coal 0.2
Cobalt
Cod (83% moisture content material) 0.54
Coke 0.184
Concrete, light-weight 0.1 – 0.3
Concrete, medium 0.4 – 0.7
Concrete, dense 1.0 – 1.8
Concrete, stone 1.7    
Constantan 23.3
Copper
Corian (ceramic crammed) 1.06
Cork board 0.043
Cork, re-granulated 0.044
Cork 0.07
Cotton 0.04
Cotton wool 0.029
Carbon Metal
Cotton Wool insulation 0.029
Cupronickel 30% 30
Diamond 1000
Diatomaceous earth (Sil-o-cel) 0.06
Diatomite 0.12
Duralium
Earth, dry 1.5    
Ebonite 0.17
Emery 11.6
Engine Oil 0.15
Ethane (fuel) 0.018
Ether 0.14
Ethylene (fuel) 0.017
Epoxy 0.35
Ethylene glycol 0.25
Feathers 0.034
Felt insulation 0.04
Fiberglass 0.04
Fiber insulating board 0.048
Fiber hardboard 0.2    
Hearth-clay brick 500oC 1.4
Fluorine (fuel) 0.0254
Foam glass 0.045
Dichlorodifluoromethane R-12 (fuel) 0.007    
Dichlorodifluoromethane R-12 (liquid) 0.09
Gasoline 0.15
Glass 1.05
Glass, Pearls, dry 0.18
Glass, Pearls, saturated 0.76
Glass, window 0.96    
Glass, wool Insulation 0.04
Glycerol 0.28
Gold
Granite 1.7 – 4.0
Graphite 168
Gravel 0.7
Floor or soil, very moist space 1.4
Floor or soil, moist space 1.0
Floor or soil, dry space 0.5
Floor or soil, very dry space 0.33
Gypsum board 0.17
Hairfelt 0.05    
Hardboard excessive density 0.15
Hardwoods (oak, maple..) 0.16
Hastelloy C 12
Helium (fuel) 0.142
Honey (12.6% moisture content material) 0.5
Hydrochloric acid (fuel) 0.013
Hydrogen (fuel) 0.168
Hydrogen sulfide (fuel) 0.013
Ice (0oC, 32oF) 2.18
Inconel 15
Ingot iron 47 – 58
Insulation supplies 0.035 – 0.16
Iodine 0.44
Iridium 147
Iron
Iron-oxide 0.58
Kapok insulation 0.034
Kerosene 0.15
Krypton (fuel) 0.0088
Lead
Leather-based, dry 0.14
Limestone 1.26 – 1.33
Lithium
Magnesia insulation (85%) 0.07
Magnesite 4.15    
Magnesium
Magnesium alloy 70 – 145
Marble 2.08 – 2.94
Mercury, liquid
Methane (fuel) 0.030
Methanol 0.21
Mica 0.71
Milk 0.53
Mineral wool insulation supplies, wool blankets .. 0.04    
Molybdenum
Monel
Neon (fuel) 0.046
Neoprene 0.05
Nickel
Nitric oxide (fuel) 0.0238
Nitrogen (fuel) 0.024
Nitrous oxide (fuel) 0.0151
Nylon 6, Nylon 6/6 0.25
Oil, machine lubricating SAE 50 0.15
Olive oil 0.17
Oxygen (fuel) 0.024
Palladium 70.9
Paper 0.05
Paraffin Wax 0.25
Peat 0.08
Perlite, atmospheric strain 0.031    
Perlite, vacuum 0.00137    
Phenolic forged resins 0.15
Phenol-formaldehyde moulding compounds 0.13 – 0.25
Phosphorbronze 110
Pinchbeck 159
Pitch 0.13
Pit coal 0.24
Plaster gentle 0.2
Plaster, steel lath 0.47
Plaster, sand 0.71
Plaster, wooden lath 0.28
Plasticine 0.65 – 0.8
Plastics, foamed (insulation supplies) 0.03    
Platinum
Plutonium
Plywood 0.13
Polycarbonate 0.19
Polyester 0.05
Polyethylene low density, PEL 0.33
Polyethylene excessive density, PEH 0.42 – 0.51
Polyisoprene pure rubber 0.13
Polyisoprene onerous rubber 0.16
Polymethylmethacrylate 0.17 – 0.25
Polypropylene, PP 0.1 – 0.22    
Polystyrene, expanded 0.03
Polystyrol 0.043
Polyurethane foam 0.03
Porcelain 1.5
Potassium 1
Potato, uncooked flesh 0.55
Propane (fuel) 0.015
Polytetrafluoroethylene (PTFE) 0.25
Polyvinylchloride, PVC 0.19
Pyrex glass 1.005
Quartz mineral 3
Radon (fuel) 0.0033
Pink steel
Rhenium
Rhodium
Rock, strong 2 – 7    
Rock, porous volcanic (Tuff) 0.5 – 2.5    
Rock Wool insulation 0.045
Rosin 0.32
Rubber, mobile 0.045
Rubber, pure 0.13
Rubidium
Salmon (73% moisture content material) 0.50
Sand, dry 0.15 – 0.25
Sand, moist 0.25 – 2    
Sand, saturated 2 – 4
Sandstone 1.7    
Sawdust 0.08
Selenium
Sheep wool 0.039
Silica aerogel 0.02    
Silicon forged resin 0.15 – 0.32
Silicon carbide 120
Silicon oil 0.1
Silver
Slag wool 0.042
Slate 2.01
Snow (temp < 0oC) 0.05 – 0.25
Sodium
Softwoods (fir, pine ..) 0.12
Soil, clay 1.1
Soil, with natural matter 0.15 – 2    
Soil, saturated 0.6 – 4    

Solder 50-50

50

Soot

0.07

Steam, saturated

0.0184
Steam, low strain 0.0188
Steatite 2
Metal, Carbon
Metal, Stainless
Straw slab insulation, compressed 0.09
Styrofoam 0.033
Sulfur dioxide (fuel) 0.0086
Sulfur, crystal 0.2
Sugars 0.087 – 0.22
Tantalum
Tar 0.19
Tellurium 4.9
Thorium
Timber, alder 0.17
Timber, ash 0.16
Timber, birch 0.14
Timber, larch 0.12
Timber, maple 0.16
Timber, oak 0.17
Timber, pitchpine 0.14
Timber, pockwood 0.19
Timber, pink beech 0.14
Timber, pink pine 0.15
Timber, white pine 0.15
Timber, walnut 0.15
Tin
Titanium
Tungsten
Uranium
Urethane foam 0.021    
Vacuum 0
Vermiculite granules 0.065    
Vinyl ester 0.25
Water 0.606
Water, vapor (steam) 0.0267 0.0359
Wheat flour 0.45
White steel 35 – 70
Wooden throughout the grain, white pine 0.12
Wooden throughout the grain, balsa 0.055
Wooden throughout the grain, yellow pine, timber 0.147
Wooden, oak 0.17    
Wool, felt 0.07
Wooden wool, slab 0.1 – 0.15
Xenon (fuel) 0.0051
Zinc

1) Asbestos is dangerous for human well being when the tiny abrasive fibers are inhaled into the lungs the place they will injury the lung tissue. This appears to be exacerbated by cigarette smoking and the ensuing ailments are mesothelioma and lung most cancers.

Instance – Conductive Warmth Switch by an Aluminum Pot versus a Stainless Metal Pot

Convective heat transfer

The conductive warmth switch by a pot wall could be calculated as

q = (okay / s) A dT                                                (1)

or alternatively

q / A = (okay / s) dT 

the place 

q = warmth switch (W, Btu/h)

A = floor space (m2, ft2)

q / A = warmth switch per unit space (W/m2, Btu/(h ft2))

okay = thermal conductivity  (W/mK, Btu/(hr ft °F))

dT = t1 – t2 = temperature distinction (oC, oF)

s = wall thickness (m, ft)

Conductive Warmth Switch Calculator

okay = thermal conductivity  (W/mK, Btu/(hr ft °F))

s = wall thickness (m, ft)

A = floor space (m2, ft2)

dT = t1 – t2 = temperature distinction (oC, oF)

Be aware! – that the general warmth switch by a floor is set by the “general warmth switch coefficient” – which along with conductive warmth switch – is dependent upon

Conductive Warmth Switch by an Aluminum Pot Wall with thickness 2 mm – temperature distinction 80oC

Thermal conductivity for aluminum is 215 W/(m Ok) (from the desk above). Conductive warmth switch per unit space could be calculated as

 q / A = [(215 W/(m K)) / (2 10-3 m)] (80 oC) 

          = 8600000 (W/m2)

          = 8600 (kW/m2)

Conductive Warmth Switch by a Stainless Metal Pot Wall with thickness 2 mm – temperature distinction 80oC

Thermal conductivity for stainless-steel is 17 W/(m Ok) (from the desk above). Conductive warmth switch per unit space could be calculated as

q / A = [(17 W/(m K)) / (2 10-3 m)] (80 oC)  

          = 680000 (W/m2)

          = 680 (kW/m2)

Leave a Reply

Your email address will not be published. Required fields are marked *