Model results with fouled coolers, and predicted "stabilized" fouling factor on the speed/load map are given in Figure 11 and Figure 12 respectively.
Based on the model results, a map of steady-state fouling factor is shown in Figure 12.
* Because the heat pump evaporator is connected to the open cooling-tower circuit, its fouling factor
will need to be raised to an appropriate value.
With the only difference between the two heat exchangers being the corrugation angle, and the soft corrugation angle BPHE having a fouling factor
one order of magnitude higher than the hard corrugation angle BPHE, it is concluded that the soft corrugation angle BPHE leads to a higher propensity for fouling.
As a rule, thermal resistance (fouling factor
) of ash deposits on heating surfaces of boilers burning pulverized solid fuel is calculated taking into account possible sintering and chemical processes during the fouling process.
Located on a heat exchanger or in a cooling water circuit, these devices indicate corrosion rate, pitting index, and fouling factor
The unit area resistance to heat transfer caused by a fouling deposit, [R.sub.f], has been dubbed the "fouling factor
" by the Tubular Exchangers Manufacturers Association (TEMA), whose listings of [R.sub.f] values are used by most heat exchanger designer.
In order to analyze the effect of SSC on heat transfer and pressure drop, the heat transfer coefficient fouling factor
[f.sub.h] and pressure drop fouling factor
[f.sub.dp] are employed (Yang et al.
Letting out fouling factors
to nature like dust-smoke, liquid and solid waste, quake and view spoiling; causes changes in the characteristics of soil, water and air.
It is extensively studied by focusing on fouling factors
, such as sludge characteristics, operational conditions, feedwater characteristics, aeration, hydraulic conditions, and membrane materials .
Users of this type of equipment have typically applied the same fouling factors
that are recommended for tube-type heat exchangers, which are summarized in the AHRI (Air-Conditioning, Heating, and Refrigeration Institute) Guideline E (AHRI 1997).
A contribution of this paper is to incorporate surface fouling at this juncture, adding the reciprocals of "fouling factors
" ([R.sub.fa] for air side and [R.sub.fw] for water side) in series with the coefficients (h) of clean surface convection.