Finite Element
Analysis (FEA)
To predict the performance of special applications, O'Brien uses
Finite Element Analysis, a computer modeling of heat distribution
within the tubing bundle. It accurately predicts temperature performance
of your bundle under the conditions of your specific application.
Using FEA techniques O'Brien has successfully designed and supplied
bundles with cuttolength self regulating heaters that can withstand
up to 1100ÿF blow down temperatures.
Static Conditions
vs. Flowing Conditions
O'Brien standard calculations assume that the process fluid
enters the bundle at or above the desired maintenance temperature.
All formulas are based on static conditions. This is truly the worst
case for fluids in small diameter pipes that do not require heat
up. A static fluid provides no heat, thus relying on the tracer
to replace all the energy lost through conduction, convection and
radiation. A static fluid also has lower thermal conductivity, which
restricts the flow of heat energy and sets up a temperature gradient
across the tube. Properly sizing the tracer and using heat transfer
aids such as aluminum mylar in the tubing bundle guarantees that
no portion of the fluid will drop below the required maintenance
temperature.
The following examples show various
conditions in which O'Brien has used FEA to accurately predict performance.
FEA
 Predicted Temperature Distribution
