Heating Systems - Steam and Condensate Loads
Calculating steam and condensate loads in steam heated systems.
The two basic situations common when calculating steam and condensate loads in steam heated systems are
- heat transfer through areas
- heating up materials
Heat Transfer through Areas
Heat transfer through areas can be expressed as:
Q = U A dt (1)
where
Q = quantity of heat transferred trough the area
A = heat transfer area
dt = temperature difference between the steam and the secondary heated fluid
Heating up Materials
The heat needed to heat up materials can be expressed as:
Q = w cp (t2 - t1) (2)
where
w = weight of material
cp = specific heat of the heated material (Check Material Properties to find specific heat for materials)
t1 = initial temperature of the heated material
t2 = final temperature of the heated material
Heat Rate
The heat rate is the heat transferred per unit of time.
Heat Transfer Rate through Areas
The formula for calculating the heat transfer rate for heat transfer through an area can be expressed as:
Q' = Q / (L h)
= U A dt / (L h) (3)
where
L = Latent heat of evaporated (condensation) steam (Check Steam Tables to find latent heat, SI or Imperial Units)
h = available time
Heat Transfer Rate when heating up Materials
The formula for calculating the heat transfer rate for heating up materials can be expressed as:
Q' = Q / (L h)
= w cp (t2 - t1) / (L h) (3b)
