Heat Exchanger Sizing Calculator

Heat Exchanger Area Formula:

\[ A = \frac{Q}{U \times LMTD} \]

Heat Exchanger Area (A): m²

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1. What is a Heat Exchanger Sizing Calculator?

Definition: This calculator estimates the required heat transfer area based on heat duty, overall heat transfer coefficient, and log mean temperature difference.

Purpose: It helps engineers and designers determine the appropriate size for heat exchangers in various thermal systems.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ A = \frac{Q}{U \times LMTD} \]

Where:

\( A \) — Heat transfer area (m²)
\( Q \) — Heat duty (W)
\( U \) — Overall heat transfer coefficient (W/m²K)
\( LMTD \) — Log mean temperature difference (K)

Explanation: The heat duty is divided by the product of overall coefficient and LMTD to determine the required heat transfer area.

3. Importance of Heat Exchanger Sizing

Details: Proper sizing ensures efficient heat transfer, optimal energy use, and cost-effective equipment selection.

4. Using the Calculator

Tips: Enter the heat duty in watts, overall coefficient (default 500 W/m²K), and LMTD (default 20 K). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical U value?
A: U values vary widely (50-2000 W/m²K) depending on fluids and exchanger type. Water-water exchangers typically range 300-1500 W/m²K.

Q2: How is LMTD calculated?
A: LMTD = (ΔT1 - ΔT2)/ln(ΔT1/ΔT2), where ΔT1 and ΔT2 are temperature differences at each end.

Q3: Does this work for all exchanger types?
A: This basic formula works for counterflow, parallel flow, and shell-and-tube with correction factors.

Q4: What affects the U value most?
A: Fluid properties, flow rates, fouling factors, and materials of construction significantly impact U.

Q5: Should I include a safety factor?
A: Yes, typical designs include 10-20% additional area for fouling and uncertainties.