1. What is a Heat Exchanger Calculator?

Definition: This calculator estimates the heat transfer rate in a heat exchanger based on the overall heat transfer coefficient, heat transfer area, and log mean temperature difference.

Purpose: It helps engineers and technicians determine the thermal performance of heat exchangers in various applications.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The heat transfer rate is calculated by multiplying the overall heat transfer coefficient by the heat transfer area and the log mean temperature difference.

3. Importance of Heat Exchanger Calculation

Details: Accurate heat transfer calculations ensure proper heat exchanger sizing, energy efficiency, and system performance in HVAC, industrial processes, and power generation.

4. Using the Calculator

Tips: Enter the U-value (typically 10-1000 W/m²K depending on exchanger type), heat transfer area, and LMTD (calculated separately). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is LMTD?
A: Log Mean Temperature Difference is the driving force for heat transfer in exchangers, calculated from the inlet and outlet temperatures of both fluids.

Q2: Typical U values for different exchangers?
A: Shell-and-tube: 300-1000, Plate: 3000-7000, Air-cooled: 10-50 W/m²K.

Q3: How do I find the heat transfer area?
A: For tubes: π × diameter × length × number of tubes. For plates: plate area × number of plates.

Q4: Does this work for all exchanger types?
A: Yes, but the LMTD may need correction factors for complex flow arrangements.

Q5: What about fouling factors?
A: Fouling reduces U-value over time. Include in initial U-value or use separate fouling factor calculations.