ENGINEERING – CHEMICAL ENGINEERING CALCULATOR
Heat Transfer Coefficient
A precise tool.
What is the Heat Transfer Coefficient & How does it work?
The overall heat‑transfer coefficient (U) quantifies the ability of a shell‑and‑tube heat exchanger to move thermal energy between the shell‑side fluid and the tube‑side fluid. It consolidates all resistances to heat flow—convective, conductive, and fouling—into a single parameter that engineers use for sizing and performance evaluation.
In a typical exchanger, heat must cross the tube wall (conductive resistance), the fluid boundary layers on both the tube‑side and shell‑side (convective resistances), and any deposits that have built up on the surfaces (fouling resistances). Each of these resistances adds in series, so the reciprocal of U is the sum of the individual resistances.
The relationship is expressed mathematically as follows:
\frac{1}{U}=\frac{1}{h_i}+\frac{r_o}{r_i}\frac{1}{k}+\frac{1}{h_o}+R_{fi}+R_{fo}
U = overall heat‑transfer coefficient (W/m²·K)
Parameters
Result
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Frequently Asked Questions
What is the overall heat transfer coefficient in a heat exchanger?
The overall heat transfer coefficient (U) measures how efficiently a heat exchanger transfers thermal energy between fluids, accounting for all heat flow resistances.
How do I calculate the overall heat transfer coefficient?
To calculate U, you need to consider the conductive resistance of the tube wall and the convective resistances on both the shell-side and tube-side fluid boundary layers.
Why is the overall heat transfer coefficient important in engineering?
U is crucial for sizing and evaluating the performance of heat exchangers, helping engineers design systems that efficiently transfer thermal energy.
What factors affect the overall heat transfer coefficient?
Factors include fluid properties, flow rates, temperature differences, tube diameter, and fouling on heat exchanger surfaces.
Can you provide an example of how to use this calculator?
Input the relevant fluid properties, flow conditions, and dimensions into the calculator to determine the overall heat transfer coefficient for your specific heat exchanger design.
Results are for informational purposes only and do not constitute professional advice.