Objectives
This higher thermal performance, per unit base surface area A may be used to achieve one of the three objectives below:
- Size Reduction: If the heat exchange rate (Q) is held constant the heat exchanger length may be reduced. This will provide a smaller heat exchanger.
- Increased heat exchange rate: This may be exploited either of two ways:
- Reduced driving temperature difference (ΔTm): If Q and the total tube length (L) are held constant, the ΔTm may be reduced. This provides increased thermodynamic process efficiency, and yields a savings of operating costs.
- Increased Heat Exchange Rate: Keeping L constant, the increased UA/L will result in increased heat exchange rate for fixed fluid inlet temperatures.
This increase in heat transfer capacity per unit volume comes at the expense of an increase in pressure drop across the heat exchanger. This pressure drop may be significant, so the heat transfer enhancement is often limited by the pumping power available.
Read more about this topic: Enhanced Heat Transfer
Famous quotes containing the word objectives:
“Along the journey we commonly forget its goal. Almost every vocation is chosen and entered upon as a means to a purpose but is ultimately continued as a final purpose in itself. Forgetting our objectives is the most frequent stupidity in which we indulge ourselves.”
—Friedrich Nietzsche (1844–1900)