Combining Heat Transfer Coefficients
For two or more heat transfer processes acting in parallel, heat transfer coefficients simply add:
For two or more heat transfer processes connected in series, heat transfer coefficients add inversely:
For example, consider a pipe with a fluid flowing inside. The rate of heat transfer between the bulk of the fluid inside the pipe and the pipe external surface is:
where
- q = heat transfer rate (W)
- h = heat transfer coefficient (W/(m2·K))
- t = wall thickness (m)
- k = wall thermal conductivity (W/m·K)
- A = area (m2)
- = difference in temperature.
Read more about this topic: Heat Transfer Coefficient
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