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- Index
Fouling Factors
Fouling factors account for the increased resistance to heat transfer between a fluid and a surface due to reactions between the fluid and the surface. Fouling factors are dependent on many variables including temperature, fluid type, surface material, and fluid velocity. The values given in the lookup table are the most often referenced baseline values. If EES is configured in SI units, the units of the fouling factors are [m^2-K/W]. In EES is configured in English units, the fouling factor will be returned in [ft^2-F-hr/Btu]. The additional resistance, R_f, posed by fouling can be determined as shown:
where
R``_f is the fouling factor returned by this function
A_s is the surface area.
The format of the FoulingFactor function is:
R_f=FoulingFactor(FluidName$)
where FluidName$ can be a string constant or string variable set to one of the following recognized fluids.
<Water>
Brackish water
City or well water
Closed-loop treated water
Engine jacket water
Hard water (> 15 grains/gal)
River water (average)
River water (minimum)
<Industrial Oils>
Engine lube oil
No. 2 Fuel oil
No. 6 Fuel oil
Transformer oil
<Petroleum Streams>
Gasoline
Lean oil
Natural gas
Rich oil
<Crude Liquids>
Heavy fuel oil
Heavy gas oil
Kerosene
Light gas oil
Naphtha & light distillates
<Industrial Gases>
Chlorine vapor
CO2 vapor
Coal Flue gas
Compressed air
Engine Exhaust Gas
Molten HT salts
Natural gas flue gas
Refrigerant vapors
Steam
<Industrial Liquids>
Ammonia liquid
Ammonia liquid(oil bearing)
Calcium Chloride solution
Chlorine liquid
CO2 liquid
Ethanol solution
Ethylene glycol solution
Hydraulic fluid
Ind. organic HT media
Methanol solution
Refrigerant liquids
Sodium Chloride solution
<Chemical Proc. Gas>
Acidic gases
Solvent vapors
Stable overhead products
<Chemical Proc. Liquid>
Caustic solutions
DEG and TEG solutions
MEA and DEA solutions
Stable side draw
Vegetable oils
Example:
$unitSystem SI
$VarInfo R``_f units =m^2-K/W
R``_f=FoulingFactor('Gasoline')
{Solution:
R``_f=0.000262 [m^2-K/W]}
References:
1. Rohsenow, W., Hartnett, J., & Cho, Y. Handbook of Heat Transfer. McGraw-Hill: Madison, 1998.
2. Kakaç, S.& Liu, H. Heat Exchangers: Selection, Rating, and Thermal Design. CRC: New York, 1998.
3. Nellis, G.F. and Klein, S.A., Heat Transfer, Cambridge University Press, 2009, section 8.1.5